Biopsych Part 1

What is a Cochlear Implant?

"Electronic medical device that does the work of damaged parts of the inner ear (cochlea) to provide sound signals to the brain" Direct stimulation auditory nerve fibers of the cochlea - bypassing the ossicles and the hair cells altogether Filtered electrical signals pull out frequency bands which go to corresponding electrodes. Mimic tonotopic mapping of sound along the basilar membrane

Acquired Synesthesia

"Induced": Reading words with letters that were individually and consistently colored produced effects substantial enough to meet behavioral markers for grapheme synesthesia. Hearing letters and numbers they would then associate in a certain color Gene x Environment- only one known case of monozygotic twins where only one has synesthesia

Nightmares

Long, frightening dreams that awaken the sleeper from REM sleep Sleeper doesn't know they are dreaming Sensory system is triggered and you can feel certain types of pain. Caused by sickness, stress, trauma, and drugs or alcohol Medications like antidepressants and drugs that control blood pressure, make them more frequent At least 25% of college students report having one or more nightmares per month

3 Basic Neurophysiology Electroencephalogram, EEG Event-related potential, ERP

An electroencephalogram (EEG) records much smaller oscillations of electrical activity that are thought to be the average across thousands of cells. An event-related potential (ERP) is basically the same kind of recording, but averaged across many stimulus presentations to show the average waveform that has been triggered by a stimulus.

Metabotropic receptors

Another kind of synaptic influence The G protein will activate other molecules, collectively known as "second messengers." These may bring about changes in the membrane potential, or influencing genetic control mechanisms, or other diverse effects.

Range Fractionation

Another mechanism the sensory system uses to handle a wide variety of light intensities Uses different light receptors: Rods -have a low threshold for light intensity -Used in the dark since minimal light energy needed to excite receptors -Loss of color discrimination Cones (color) -have a high threshold for light intensity -This allows for distinct determination of brightness.

Patel Anatomy and Physiology of the Anterior Pituitary Anterior Pituitary Anatomy

Anterior Pituitary: -Consists of many different endocrine cells, that each secret a different hormone. -It is the front division of the pituitary gland. -Synthesizes the hormone it releases. The hormones are tropic hormones, meaning that they act on a different endocrine gland. -Can reach all glands through blood stream but only target gland has the receptors for it. Anatomy: -Located beneath Hypothalamus -Pituitary artery run through it and the hormones flow out through there -Releasing hormones from the hypothalamus tell the anterior pituitary when it should release certain tropic hormones.

Standard views of brain

B9 Coronal also called transverse or cross section. In half like bread In humans, dorsal/ventral sometimes replaced with superior/inferior Also, anterior/posterior more common than rostral/ caudal. slices like hot dog style/filet Sagittal: midline cut

Transduction of Stimuli-Labeled Lines Labeled Line theory

Each nerve input into the brain is connected to only one type of sensory information. Allows to differentiate between feelings of touch: pain, temperature, texture Action potential initiated for smell will go down a different nerve than an action potential for sight They are also help differentiate within a sense such as touch to determine sensations such as light touch, vibration, and stretching.

Study

Measured adaptation in 15 control, and 15 schizophrenic patients. This study was beneficial because it showed a definitive link between Schizophrenia and a efficiency coding deficit. Now physicians are more easily able to diagnose patients who they believe to be Schizophrenic. The most important results unearthed that the Schizophrenic N=15 group had "substantially weaker" responses to repeated visual stimulation and touch stimulation yielded that same results.

Cabral Olfaction In humans

Olfaction -sense of smell , a chemical sense that helps us to identify food and make sure it's not spoiled and therefore unfit to consume. Odors give us the sensation of smell 10,000 different odors we can detect About 5000 odors we are able to tell apart Anosmia - odor blindness Humans vs other Mammals

The Olfactory Apparatus

Olfactory epithelium - where our six million olfactory receptor cells reside within this mucous membrane Olfactory epithelium is located on top of the nasal cavity Three Types of Cells are found within the Olfactory Epithelium -Supporting cells -Basal cells -10 million olfactory receptor cells

Two types of Retinal Receptive Fields

On center/ Off surround: -Flashing a bright spot in the center increases the cell's response. -Flashing a bright ring in the surround inhibits the cell's response. -There is little or no response to a large (full field) spot of light that covers both the center and the surround Off center/ On surround: -Has the opposite arrangement. -It gets inhibition from a small spot of light in the center, and excitation from a bright ring in the surround.

Classification of Sensory Systems-Photic system

Only found in eye Mainly rods (black and white), cones are color, and found on back of retina Photoreceptors take in photons and makes an image in your brain for you to be able to see It is the system we use for vision and perception of the environment around us Receptors are called photoreceptors Photons form light sources and reflected light enters the eye to stimulate the receptors.

Outer external ear

Outer external ear: The outer ear is shaped to filter sound. Pinnae are the fleshy variations visible as the external part of the ear. Vary in shape and size. Enhances reception of 2,000-5,000 Hz frequencies. Ear canal, also known as the auditory canal, is a tube that leads from the external structures of the pinnae to the tympanic membrane. The tympanic membrane, more commonly known as the eardrum, is a taut membrane that divides the ear canal from the middle ear.

Superior olivary nuclei

Output from both left and right cochlear nuclei extends to each superior olivary nuclei Bilateral input allows for first binaural, two-ear, processing to occur here ability to compare input from the two ears, very useful for sound localization For example time differentials in hearing lead to selective response -Neurons in the olivary complex selectively fire as a function of time difference in arrival of sound at the two ears

-Peptide hormones -Amine hormones -Steroid hormones

Peptide hormone: -is made up of a short string of amino acids -Peptides are small protein molecules -Different peptide hormones consist of different combinations of amino acids Amine hormones: -are smaller and simpler, consisting of a modified version of a single amino acid (hence their alias, monoamine hormones) Steroid hormones: -are derivatives of cholesterol and thus share its structure of four rings of carbon atoms. -Different steroid hormones vary in the number and kinds of atoms attached to the rings. -Because steroids dissolve readily in lipids, they can pass through membranes easily.

How is it helpful?

Perception of the sensation of sound Conditions: Damaged hair cells in the inner ear (cochlea): -Moderate to profound loss in one or both ears -Receive little to no benefit from hearing aids Bilateral (listening in 2 ears) improvement: -Identify direction of sounds -Selection sound from desired source (attention)

Intracranial electrodes ASK FOR SLIDES/PIC

Periaqueductal Gray (PAG) Similar to the process of administering opiates Stimulation: neurons in the brainstem Serotonin released into the dorsal horn Connects with inhibitory interneurons Produces either enkephalin or dynorphin Bind to receptors on axons of incoming pain transmissions

Limitations

Photopigments don't have narrow spectral distributions No red cones and green cones, receptor pigments have broad sensitivities and overlap quite a bit Photopigments DO have peaks of sensitivities, but they are not that far apart All three cones are sensitive to almost all spectral regions, but are most sensitive in their respective optimized color regions Trichromatic theory does not explain many color perception phenomena Does not explain the contrasting afterimages we perceive when we inspect one color for an extended period of time Complementary afterimages are better explained by the opponent-process theory.

What is a photoreceptor?

Photoreceptor-A neural cell in the retina in the retina that responds to light. Two classification of photoreceptors: rods and cones Cones have many different varieties for the different wavelengths of light. Rods to respond to any and all visible light regardless of the wavelength. DUKE SLIDE 5

Mechanism of Vision

Phototransduction - initiation of vision at the rods and cones -Conversion of light energy to nerve impulse -Activation of Rhodopsin *When light falls on this cis retinal, it undergoes isomerization and forms trans retinal. The opsin molecules becomes free and catalyzes the transformation of GDP to GTP. The ion channels close and inhibit the release of inhibitory neuro-transmitter thus the generation of the nerve impulses which is carried to the brain for nerve interpretation

Ageusia

Taste disorder - loss of taste functions on the tongue Many causes, including zinc deficiency, vitamin B3 deficiency, anxiety disorders, cancer, damage to tongue, damage to liver, side effects of certain medications, etc. Neurological cause: caused by damage to the nerves that support the tongue - specifically the chorda tympani (CN VII) and the glossopharyngeal nerve (CN IX) ← lingual branch These nerves support the tongue, and when they are damaged there is a loss of the ability to detect the 5 basic tastes.

Lateral Inhibition

This is the reason for the opposite effects of light in the type of retinal ganglion cells Lateral inhibition: The phenomenon by which interconnected neurons inhibit their neighbors. There is little or no response to a large spot of light because excitation in the center cancels the inhibition from the surround and vice versa

Nociceptive:

This pain represent the normal response to noxious (harmful, poisonous, or very unpleasant) insult or injury of tissues such as skin, muscles, visceral organs, joints, tendons, or bones Somatic: Musculoskeletal (joint pain, myofascial pain), cutaneous; often well localized Visceral: hollow organs and smooth muscle; usually referred. Ex. Sprains, bone fractures, burns, appendicitis

Diagram of how it works

This simple cortical cell receives input from a row of on center ganglion cells and so responds better to a bar of light than to any single spot of light This complex cortical cell receives input from a row of simple cortical cells, and so responds better to a bar of light moving across the retina than to any stationary bar of light. The bar must have a particular orientation as it moves across the retina to best stimulate this neuron

V1 V2 V4

V1: -Signal comes from the Lateral Geniculate Nucleus(LGN) where it gets divided into two separate streams one for color processing and the other for form processing -Wavelength selective cells that respond only if a sufficient amount of light of their preferred wavelength is reflected from it -Help discriminate between different wavelengths V2: -Studies have shown there might be some cells in V2 that are involved in an initial spatial wavelength-differencing operation -The cells here have small receptive fields so they only respond to some parts of the field of view V4: -Electrophysiological recordings in the Macaque monkeys V4 region showed these areas as being sensitive to color -Infer that it is also involved in color processing in humans -Patients with certain lesions lose the ability to recognize color

Stress-Induced analgesia (SIA)

Stress-Induced analgesia (SIA): Stress may help reduce pain Some gravely wounded soldiers experience no pain after their injuries Activates 1) opioid-dependent form of analgesia (can be blocked by naloxone) 2) non-opioid analgesia system (may rely on endocannabinoids) Varies greatly and Can depend on: -Opioid sensitivity -Startle response -Age -Gender specific hormones -Prior exposure to stress/pain Descending pain pathway activated

Geoly Anatomy and Physiology of The Posterior Pituitary Structure of the Posterior Pituitary Gland

Supraoptic Nucleus -Hypothalamic Nucleus -Magnocellular (large) Neurosecretory Neurons -Release Vasopressin and Oxytocin Paraventricular Nucleus -Hypothalamic Nucleus -Magnocellular (large) Neurosecretory Neurons -Release peptide hormones Vasopressin and Oxytocin Pituitary Stalk -(unmyelinated axons) -Terminate on Capillaries Capillaries

Taste receptor cells (taste buds)

Taste buds produce a graded response, they don't have "all or none" characteristic (no vg-Na+ channels), thus no action potential Gustatory afferent axons that pick up the information do produce action potentials (they do have vg-Na+ channels)

Primary motor cortex (M1)

in front of central fissure Has a a map of the "motor homunculus." It is predominantly contralateral in its control of voluntary muscle activity.

Basal Ganglia

includes caudate nucleus, globus pallidus, and putamen Dark grey groupings of cells B29, motor deficits come in here such as parkinson's. Also controls specific movement such as trotting/cantoring in horses Motor control systems include some buried structures

Chemical Endogenous opioids Opioid receptors ASK GREENE ABOUT SLIDES

innate pain relieving neuropeptides Attach to opiate receptors to produce analgesic effect Endorphin: brain stem Enkephalin: spinal cord Dynorphin: spinal cord hypothalamus Opioid receptors

MRI data and Neural Correlates

fMRI data showed that although oxytocin administration didn't increase overall brain activity, there was significant activation of the ACC and dmPFC when performing the "friend or foe" task Oxytocin administration returned activity in these regions to levels found in typical development people. The study also noted oxytocin's suppressive effects on the amygdala response to emotional stimuli, confirming many other findings (Kirsch et al., 2005).

Seibert Etiology of deafness Hearing Steps

hearing: easy as 1, 2, 3 mechanics of inner and middle ear transduction of sound in inner ear and cochlea interpretation of sound that happens in nuclear

Seibert let's talk about sex: The role of hormones in sexual behavior what is sex? reproduction/sex

what is sex?: reproduction ≠ sex -Different "families" of organisms procreate according to their underlying biology + environmental pressures. -Single-celled organisms reproduce asexually -Eukaryotes reproduce sexually -What makes human sexuality different from (most) others in the animal kingdom?

Sensory-Conflict Theory

sickness occurs when we receive contradictory sensory messages - differences in vestibular and visual input. Ex: when an airplane bounces in turbulence, the vestibular system signals various changes in direction and acceleration, but the visual system is not impacted because the planes interior is constant Hypothesis: nausea has evolved to help the body get rid of ingested toxins, after experiencing dizziness due to potential poisons. Ye slide 6

Levels of sensory processing

slide 7 Secondary is most primitive input, more so than primary cortex

Somatosensory Feral slide 3 Slide 4 Look up definitions of these in book

somatosensory system has Dorsal Column System: Dermatome: strip of skin enervated by particular spinal nerve Thalamus: top of brain stem that trade info with corte Primary Sensory Cortex: receive info regarding own modality from thalamus Nonprimary Sensory Cortex, secondary sensory neurons S2 Primary Somatosensory Cortex (S1): post central gyrus in parietal lobe

Recap

some behaviors may be explained mechanistically (Descartes) with modern neuroscience pressing the view that all mental activity is mechanistic electrical nature of nerves and muscles (Galvani) which provides the information and control for this mental activity individual neurons of the brain and their connections provide the circuit structure for brain activity (Golgi & Cajal) specific locations in the brain are dedicated to specific mental functions (Gall, Spurzheim, Broca, Wernicke)

Hippocampus HM

temporal lobe roll in memory? Beginning in the 1950s, there was a new direction of speculation about the locus of memory based on Penfield's work with epileptic patients. Hippocampus seemed to be critical HM B42

The difference between sex and reproduction Oxytocin and Vasopressin

the difference is pleasure . . . What differentiates human animals from much of the animal kingdom is that humans have sex not only for procreation, but also for recreation. Since it is difficult to QUANTIFY & MEASURE "pleasure", scientists look to the presence or absence of the orgasm as a determining factor. ORGASM (d) : "the brief, extremely pleasurable sensation experienced by women & men during intercourse; characterized by muscular contractions in women & men Oxytocin: -A "nonapeptide" hormone -Released during sexual activity in females (and other times too!) -WARNING: may elicit trust, monogamous pair-bonding, and other dangerous behaviors. Vasopressin: -A "nonapeptide" hormone -Released during sexual activity in males (and other times too!) -FDA STATEMENT: may cause heightened attraction to sexual partner as well as subsequent "feelings"

Inferotemporal cortex

vision comes in the occipital lobe, Subsequent work has shown that vision is more extensive, i.e., not just occipital. Also into temporal lobe now. Identifying objects V2 And even into parietal lobe, with somatosensory equivalents, where things are in the world (depth perception) V3

why should sex be fun? study

who: garth, fletcher, simpson, campbell and overall (2015) what: use evolutionary theory to propose how the oxytocin (OT) system, originally thought to be responsible for mother-child bond, became co-opted to facilitate pair-bonding in parents. how this redefines sex: Since oxytocin facilitates the mother-child bond that encourages a mother to protect and care for her offspring, the research demonstrates the relevance of recreational sex in human animals.

Talking about the brain

Spinal cord for humans: it folds down B53

Brain Structures and pathways of theMotor System Spinal cord Major pathways

Spinal cord: Brain sends commands to spinal cord through pathways. Acts as a mediator to control behavioral responses. Focus on descending tracts bc of motor function Major pathways: Pyramidal system Extrapyramidal system

Hrovat stages of sleep Why do we sleep? Human sleep has different stages REM and Non Rem sleep

-Inactivity Theory -Energy Conservation Theory -Restorative Theory -Brain Plasticity Theory Human sleep has different stages: -Electroencephalography (EEG) provides a way to define, describe, and classify levels of arousal and stages of sleep -Also measure eye movements and muscle tension in sleep studies -Lead to discovery of REM and non-REM sleep REM sleep - also characterized by: fast EEG waves, no postural tension, and rapid eye movements Non-REM sleep: - divided into 3 stages Rapid- eye- movement (REM) sleep: Also called paradoxical sleep Characterized by small amplitude, fast waves Non- REM sleep Divided into stages 1-3 Distinct EEG activity HROVAT SLIDE 4

Summary:

-Studying EEG's of individuals while sleeping has given us an understanding of the varying neural activity during different stages of sleep -Sleep consists of non-REM and REM sleep -Stages 1-3 are part of non-REM sleep -REM sleep is the deepest sleep, where we experience dreaming

4 Categories of Color Vision Capabilities (among mammalian species)

1. Excellent trichromatic color vision -Diurnal primates -Humans -Rhesus monkey 2. Robust dichromatic color vision -Species with 2 kinds of cone photopigments & a large population of cones -Dogs -Pigs -Male South American monkeys 3. Feeble dichromatic color vision -Species with 2 kinds of cone pigments but very few cones -Domestic cat -Coati 4. Minimal color vision -Species that have one type of cone pigment -Rely on interactions between rods & cones to differentiate wavelength -Owl monkey -Raccoon -within a taxonomic family: diurnal species (i.e. coati) have better color vision than nocturnal species (i.e. raccoon)

Summary

1. Forebrain system: a region called the basal forebrain promotes SWS by releasing GABA into the tuberommillary nucleus in the hypothalamus 2. Brainstem system: the reticular formation projects axons to the brain, activating it to promote wakefulness 3. Pontine system: Near the locus coeruleus is a region that sends widespread projections to promote REM sleep. Axons projecting to the spinal cord profoundly inhibit motoneurons so that they cannot fire, causing deep muscle relaxation (atonia) 4. Hypothalamic system: a region in the hypothalamus including neurons that use orexin as a nuerotransmitter sends axons to the other three sleep centers and seem to coordinate them, enforcing patterns of sleep. Loss of orexin can lead to disorganized sleep such as REM like muscle atone while still awake (narcolepsy)

Neural codes How does neuronal activity specify the nature of the stimulus?

1. A sensor cell selectively responds to a stimulus attribute, e.g., color, flavor, sound frequency. Then unless modified by interactions with other neurons, the brain is informed of that attribute through channels (axons) that come from that sensor. One only needs to send a few spikes to provide this qualitative information. 2. Rate of firing of the neuron can specify the intensity of the stimulus, this being known as a rate code. Other methods are theoretically possible, such as having different neurons fire depending on the intensity, but a rate code is generally assumed unless proven otherwise. 3. Stimuli may have complex attributes, such as a mixture of odors or a visual pattern. This means that many channels (axons) are sending or have received simultaneous information. This is called a "distributed code." At best this is an amorphous concept that if often invoked when one has not developed a comprehensive theory. Generally it is not clear how a unified decision about the stimulus can come from activity in neurons that are scattered among the population.

Lee Other Sleep Disorders + Drugs as Sleeping Aids 1. Disorders of initiating and maintaining sleep (Insomnia) 2. Disorders of Excessive Drowsiness

1. Disorders of initiating and maintaining sleep (Insomnia): -Drug-related insomnia caused by: -Use of stimulants -Withdrawal of depressants -Chronic alcoholism -Insomnia associated with psychiatric disorders -Sleep apnea (insomnia associated with sleep-induced respiratory impairment) -Sleep-maintenance insomnia (difficulty staying asleep) 2. Disorders of Excessive Drowsiness: -Narcolepsy -Drowsiness associated with psychiatric problems -Drug-related drowsiness -Drowsiness associated with sleep-induced respiratory impairment (sleep apnea)

HOW THE SNB DEVELOPS IN MALES VS. FEMALES

1. In both sexes spinal motoneurons make connections with the bulbocavernous muscle early in development 2. In both sexes the muscle expresses androgen receptors 3. In males circulating testosterone binds to the androgen receptors. In females, the receptors remain unoccupied 4. In males, the activated receptors promote the survival of the muscle and cause it to secrete unknown factors, which are picked up by the motoneurons. In females, the lack of receptor activation causes the muscle to die, and no factors are produced 5. In males, the factors picked up by the motoneurons promote their survival. In females,the lack of these factors causes the motoneurons to die

1 Early History of Neuroscience

1600 BCE: Egyptian papyrus provides the earliest reference to the brain. 2 individuals w brain damage and how they helped them Greek concept of animism. Driving force for soul. what gives all things their nature. Especially living things. Ex. Water has a flowing property. Mental activity of humans was provided by a unique form of animism. Most cases they tied it to the heart as the life force. Body fluids carry Awareness, vague in their description

3. Disorders of sleep-waking schedule Sleep state misperception 4. Dysfunctions associated with sleep, sleep stages, or partial arousals

3. Disorders of sleep-waking schedule: Temporary disruption caused by: -Time zone change by airplane flight (jet lag) -Shift work, especially night work -Persistent disruption (irregular rhythm) Sleep state misperception- sleeping without being aware of it; individuals with this sleep disorder report they did not sleep, when the EEG showed signs of sleep & they failed to respond to stimuli 4. Dysfunctions associated with sleep, sleep stages, or partial arousals: -Somnambulism (sleepwalking) -Sleep enuresis (bed-wetting) -Night terror -Nightmares -Sleep-related seizures -Teeth grinding -REM behavior disorder (RBD)

Johnson Dream States 6 Different Dream States Daydreams Functions of daydreams Brain

6 Different Dream States: Daydreams Normal Dreams Lucid Dreams False Awakenings Nightmares Night Terrors Daydreams: Short-term attachment from one's immediate surroundings, a person's contact with reality is blurred and partially substituted by a visionary fantasy. Happy and pleasant thoughts, hopes or ambitions, imagined as coming to pass, and experienced while awake 70-120 minutes of their waking day Semi-awake during daydreams Functions of daydreams: Eric Klinger: most daydreams are about ordinary events and help to remind us of mundane tasks Over 75% of workers in "boring jobs" such as lifeguards and truck driver, use vivid daydreams to "ease the boredom" of the routine tasks When the brain consolidates learning May help people sort through problems and achieve success Brain: Brain areas associated with complex problem-solving are in fact highly active during these episodes.

Vestibular Nuclei Motion sickness

A brainstem nucleus that receives information from the vestibular organs through cranial nerve VIII. Outputs project to motor areas throughout the brain, including motor nuclei of the eye muscles, the thalamus, and the cerebral cortex Motion Sickness: can result from too much vestibular excitation. caused by movements of the body that we cannot control. Ex: passengers in a car are more likely to feel motion sickness than the driver. Ye slide 5

Sensory Processing Disorder SPD vs. Autism

A condition in which an individual's auditory, visual, and somatosensory do not integrate properly resulting in inappropriate responses More Prevalent in Children than Autism and as common as ADHD Struggle with how to process stimulation UCSF researchers found abnormal tracts of white matter. Not Recognized by the American Psychiatric Association as a distinct disorder Brain Wiring differences between SPD and Autism SPD vs. Autism: Both: Deficits in the brain region that handles basic sensory information Autism: Impairments in brain connections related to processing facial emotion and memory SPD: Impairments in the parts of the brain that link auditory, visual and tactile sensory processing systems Slide 12: Images show the abnormality of white matter in the back of the brain where the connections of the visual, auditory, and somatosensory connect. Signs of SPD slide 13

Ganglia

A ganglion consists of a group of nerve cell bodies that are not in the brain or spinal cord (CNS). Fiber brings sensory info from skin, before it goes into spinal cord it goes into the Dorsal root ganglia. sympathetic ganglia parasympathetic ganglia Butterfly area is neurons, white is the myelin wrapping axons, grey matter is cell bodies and grey bc of preservatives

Odor coding glomerulus, spatial recognition

A glomerulus receives information from type of receptor , so the odorants that bind to these receptors will produce different patterns of activities on the glomeruli. In order to be able to recognize an odor there has to recognition of a particular pattern of activity that happened in the glomeruli when that odor was sniffed. So spatial recognition is key when trying to detect a particular odor. cabral slide 9

Duke Photopic and Scotopic retinal anatomy The eye is a camera

A layer of neurons captures light and projects the image of the external world in the back of the eye. The retina, a layer of neurons, turns the light into neural signals, in a process called transduction. Another camera feature of the eye is the cornea-a transparent, convex layer over the eye DUKE SLIDE 3

Satterfield: Mechanisms of sound Localization What is sound localization? Two binaural cues

A listener's ability to identify the location or origin of a detected sound in direction and distance We have the ability to locate sounds Evolutionary significance (predators) The two binaural cues, Intensity differences and latency differences play a major role The auditory system analyzes these 2 binaural cues

Courtship behavior of ringdove

A male ringdove sees an attractive female, this visual stimulation provides a neural-to-neural transmission of information The perception of an available mate activates a neural-to-endocrine signal, leading the hypothalamus to secrete GnRH GnRH provides a endocrine-to-endocrine signal to the anterior pituitary to release LH and FSH LH and FSH, provide an endocrine-to-endocrine signal, promoting the testes to increase testosterone release The testosterone then acts on specific neurons in the male's brain, endocrine-to-neural signal, leading to display of courtship behavior, bowing coos If the female dove responds to the courtship display, this provides further visual stimulation to the male dove, leading to another iteration of this signaling cycle

Fun facts about taste

A recent study showed that eating sweet foods helps form a memory of a meal Everyone has a different number of taste buds As you age, your taste buds become less sensitive Flies and butterflies have taste organs on their feet, so they can taste anything they land on

Night Terror

A sudden arousal from Stage 3 sleep that is marked by intense fear and autonomic activation Happen during non-REM sleep Sudden reaction of fear that happens during the transition from one sleep phase to another Common in children during the early part of an evening's sleep Occur about 2 or 3 hours after a child falls asleep, when sleep transition from the deepest stage of non-REM sleep to lighter REM sleep A child might suddenly sit upright in bed and shout or scream in distress Breathing and heartbeat might be faster, sweating can occur, thrashing around, and acting upset and scared

Properties of the human photopic and scotopic visual systems

ADD IN WORDS FROM DUKE SLIDE 7

ALTERNATIVE EXPLANATIONS HOMOSEXUALITY IN WOMEN

ALTERNATIVE EXPLANATIONS: Early social experience... -Affects development of INAH-3 -Determines later sexual orientation Sexual experiences as an adult could affect INAH-3 structure Smaller nucleus in some homosexual men may be the result of their homosexuality rather than the cause HOMOSEXUALITY IN WOMEN: -Markers of exposure to androgen as a fetus: sounds emitted from the ears, finger length patterns patterns of eye blinks, skeletal features -Lesbians, on average, exposed to slightly more fetal androgen than were heterosexual women -NOT PREDICTIVE: cannot use the features to produce whether a woman is gay and clearly fetal androgens cannot account for all lesbians

What is Analgesia? Pain Transmission/Gate control theory huang slide 3

Absence of or reduction in pain (i.e. pain relief) Gate Control Theory: -Spinal "gates" control the signal of pain that gets to the brain -Can be modulated to facilitate or block pain -Goal: keep the gates closed to cut off the pain signal pic 2: inhibitory neuron, don't feel any pain, pic 3: large fiber input encourages inhibitory neuron to close gates for pain perception

Acute Pain vs. Chronic Pain

Acute pain -Begins suddenly and is usually sharp in quality. -Serves as a warning of disease or a threat to the body -Might be mild and last just a moment, or it might be severe and last for weeks or months -Usually won't last more than 6 months -Disappears when the underlying cause of pain has been treated or has healed Chronic Pain -Pain that persists despite the fact that the injury has healed -Pain signals remain active in the nervous system for weeks, months, or years -Physical effects include tense muscles, limited mobility, a lack of energy, and changes in appetite -Emotional effects include depression anger, anxiety, and fear or re-injury -Such a fear might hinder a person's ability to return to normal work or leisure activities CBT, physical therapy to help with chronic pain Slide 14

Quieting unnecessary information Central modification of sensory information The receptors in adaptation

Adaptation is one way to limit sensory information, there are other however In adaptation, a problem occurs if the action potentials are occurring infintium, therefore numerous physical barrier prevent this: -Simply closing eyelids form time to time prevents overload of the visual system. -tiny structures in the middle of the ear canal prevent the intensity of sounds for the auditory system. The ultimate plan of receiving only the necessary information is the brain choosing its own input. Central modification of sensory information allows the brain to choose the information coming from the sensory and pain pathways. The receptors in adaptation: phasic/tonic also carry information similar to the five types of somatosensory receptors. Pacinian corpuscles are also phasic receptors, once they get vibrations or pressure sensations, it relays that message to the CNS. Tonic receptors are nociceptors, they respond to pain and tissue damaging stimuli. Thus, adaptation is a necessary process to stop constant input to the nerve cells.

Age Genetics

Age: sleep decreases as you get older REM sleep also decreases as you get older Adults should get 7-9 hours of sleep Genetics: -DEC2 Gene Mutation (chromosome 12) Allows people to have a more efficient sleep Only need 4-6 hours of sleep each night May be associated with resistance to sleep deprivation effects -Future testing Replicated in mice Can help people sleep more efficiently Decades away from an actual answer

Alfred Kinsey virginia johnson + william masters

Alfred Kinsey: a biologist-turned-sexologist what he did: authored 'the kinsey report', the first research project to collect data spanning many dimensions of human sexuality. how this redefined sex: the results reported substantiated the existence of an enduring 'gay' population, thereby creating categories of human sexuality. virginia johnson: a research assistant turned sexologist william masters: a gynecologist turned sexologist what: studied physiological markers of human sexual experience how this re-defined sex research: extended conceptual and statistical research to experientially examining physiological aspects of human sexuality, thereby creating a basic model for future research on physiology of sex.

All or none concept

All or none: if it reaches the threshold it will go no higher, opening all pores to highest height. Also will travel reliably to the end and not get weaker Here is another meaning of the all or none concept -- that is, once a spike is initiated in an axon, the spike will travel down the full length of the axon without growing smaller. In other words, unlike electrical signals sent down copper wires, the spike pulse does not grow weaker as it travels. [But note failure of spikes at the telodendria (fine fibers).]

The Sensorimotor System Sensory Processing

All sensory organs have receptor cells: -They sense forms of energy -Vary depending on sensory organ -Filter energy from environment for what's important -Convert stimuli into electrical signal for the nervous system Stimulus: An environmental energy/event that starts a sensory response

Hearing Thresholds

All species have unique auditory capabilities that have helped solve important problems associated with survival. For example, the North Atlantic right whales hearing is estimated between 10Hz and 22Kz. In comparison to a human, we can hear sounds at frequencies from about 20Hz to 20,000 Hz. We hear best from 1000 Hz to 5,000 Hz, where human speech is centered. Hearing loss may reduce the range of frequencies a person can hear. It is possible as you age, you lose the ability to hear higher frequencies. There are sounds that even humans with the best hearing can't hear. We can't hear the sound of a dog whistle, but a dog can because dogs have a much larger hearing range than humans do.

Transduction of Stimuli- Sensory Transduction

An external stimuli excites the cell This turns the environmental energy into an electrical pulse called a generator potential (action potential) The change from a stimulus in the environment into an electrical action potential is sensory transduction This is how our body translates events in our environment into data our brain can use

Sleep may aid in memory consolidation

An initial study was conducted in 1924: -Participants were trained in a verbal memory task and tested 8 hours later, either after a night of sleep or 8 hours later in the day -Results: Better retention when sleep intervened the learning period and test of recall -Supporting evidence has been completed since then that confirms this finding REM sleep studies suggest that sleep improves performance on perceptual skills: -When learning visual discriminations, humans show little improvement after one session, but show considerable improvement 8-10 hours after with REM sleep -If deprived of REM sleep, there is a failure to show later improvement -However, REM is not absolutely necessary for learning

Intracellular methods

An intracellular method provides the most information about electrical events, and is needed for recording of the resting membrane potential. Initially, it was used only with very large neurons, as can be found in some invertebrates. It commonly required that the tissue be dissected out and pinned into a Petri dish. Newer recording methods have made it possible to do intracellular recording in smaller neurons, often done using a very thick slice of tissue. To measure resting membrane potential: you need an electrode sitting in the cell, but it is in a petri dish

Yeh Gonadal hormones vs sexual differentiation Androgen-insensitive women Hormones

Androgen-insensitive women have: -Male XY chromosomes -Internal testes -have a vagina and breasts -Don't have oviducts or a uterus attracted to males identify as women. Question: • Who can they marry "by law"? • Which public restroom do they use? • Which gender roles do they live by? Hormones: -Testicular hormones- direct masculine development of the fetal body. Androgens- testosterone - Behavioral research shows similar hormonal influence on the fetal brain

5 Pain Pathways and Brain Structures Archispinothalamic Pathway Paleospinothalamic Pathway Spinothalamic System

Archispinothalamic Pathway: -Oldest pathway pain stimuli can take to reach the brain -This tract also sends collaterals to the hypothalamus and to various nuclei in the limbic system -No somatotopic organization Paleospinothalamic Pathway: -The paleospinothalamic tract is composed of small diameter fibers that conduct nerve impulses slowly -Like the archispinothalamic pathway, there is no somatotopic organization -It projects widely into the reticular formation at all levels of the brainstem Spinothalamic System: -Also known as the anterolateral system, and is the most recent pathway which is traveled by rapid component of pain -A somatosensory system that carries most of the information on pain and temperature from the body to the brain -Has somatotopic organization -Each hemisphere receive pain inputs from the contralateral side of the body

Measuring resting potential Extracellular recording

As indicated before, one can't register the resting membrane potential unless one electrode is inside the cell. Extracellular recording: But if one is just outside, it can register the large, brief permeability from a spike!! Most often this is done with a fine tungsten needle that is insulated except at the tip. The metal tip will be coated with a small amount of metal salt, which still is necessary to sense the permeability pressures. Extracellular recording, also known as single-unit recording The brief pulse provides the basic signal that carries information or elicits action. Recording a burst of spikes

2/23 Jorgensen Sleep Deprivation

As we age, the total amount of sleep we get declines, while the number of awakenings increases. Insomnia (lack of sleep) is a common complaint of the elderly In humans and other mammals, the most dramatic decline is in stage 3 sleep; 60-year-old people spend only about half as much time in stage 3 sleep as they did at age 20. By age 90, stage 3 has typically disappeared. This decline may be related to diminished cognitive functioning.

Ascending Tracts vs. Descending Tracts

Ascending Tracts (sensory) vs. Descending Tracts (motor) Slide 6 dorsal column at top in blue spinal columns

White matter

B47 This is the mass which fills much of the center of the brain, and consists mainly of axons (the color comes from the axon wrapping -- myelin).

Volley Theory

Auditory nerves fire according to the Volley Theory up to several thousand Hz. Developed by Wever and Bray in 1934 So fibers can fire at different times. Individual neurons fire as often as possible and the entire group of fibers can send spiked at the frequency of the sound wave.

Autonomic nervous system

Autonomic: control external organs and glands, bp, automatic processes. Don't have to think about it Subdivisions being: Sympathetic and Parasympathetic Sympathetic: Challenges/threats. Feeding, fighting, fleeing, and sex. Heart rate increases, blood away from skin into major muscles, sweating goes up, digestion goes off. Said to prepare for action. Sympathetic has ganglia in a chain beside the spinal cord. Parasympathetic: digesting food, resting state. For relaxation and recovery. Turn on digestion, heart rate decreases. Come from base of the brain and Parasympathetic generally has ganglia near the target organ, not in a chain

Receptor Identification Techniques

Autoradiography Immunocytochemistry In situ hybridization

Tips For Avoiding Sleep Deprivation During Midterms/Finals

Avoid caffeine or stop drinking it within 10 hours of sleeping Avoid alcohol - it disrupts normal sleep patterns Use your bed for sleeping only - do not use your bed for studying/homework Take a nap - 20 minute naps help boost alertness and physical stamina Set a consistent bedtime and wake time Exercise regularly Don't pull all-nighters - your brain will not work properly the next day Don't stress (yeah right)

Cerebrum

B 18 The cerebrum is divided into four lobes Frontal lobe: central fissure separates this and parietal lobe, front, long term planning/judgement/thoughts, top is auditory cortex Parietal lobe: Top middle, S1 B 20 Occipital lobe: bottom of brain/front, processing of visual stimuli, Primary visual cortex (V1), goes from optic nerve to the thalamus then V1 Temporal lobe: back of head Ventricles are fluid system in the brain

Primary auditory cortex (A1)

B24 Top of temporal lobe, superior temporal gyrus

Linkages for language

B25 Expand auditory system to include language things Brain stem nuclei to transmit sound itself, also for localizing sound, goes up both sides, a little more to opposite side (contralateral) Superior Temporal Gyrus Sound message from one side goes to both hemispheres.

Caudate nucleus Thalamus Pineal body Colliculi

B30 Here is a cut-away view that shows these structures, as well as pineal body and the colliculi. Colliculi are the bumps, controls where you look. Auditory are on the lower ones. aka - corpora quadrigemina in lower vertebrates, called the tectum. Superior colliculus involved in control of eye movement, inferior colliculus in sound localization.

Cerebellum

B31 The basal ganglia have strong downstream connections to another motor structure, the cerebellum Tightly wrapped, highly compressed folds, said they help coordination of movements making them more precise, but also recently discovered they might be involved in some ways of learning

BMAL1 Timing of the molecular clock Well-known regulator of clock

BMAL1: -This protein is expressed in a circadian pattern in both the SCN and peripheral tissues -CLOCK protein levels do not oscillate in the SCN and ONLY in some peripheral tissues. Timing of the molecular clock: -This can be modulated by post-translational mechanisms using phosphorylation, acetylation, and/or ubiquitination pathways. -These modifications impact the stability and/or translocation of core molecular clock components with greatest impact on period length. Well-known regulator of clock: -This function is through changing phosphorylation status is casein kinase1. -This serine/threonine kinase has been the subject of studies in both hamster and humans in which the mutations of either CK1 or PER2 affect period length. -The activity shows a strong circadian rhythm antiphase to the rhythm of histone H3 acetylation.

Basal ganglia Damage to systems

Basal ganglia is major extrapyramidal nuclei and Helps plan movements Impulses sent through the extrapyramidal fibers to the basal ganglia Basal ganglia modifies impulses and reports information fibers directed down to synapse Or sent back to cortex. Damage to systems: In pyramidal system: Lesions can cause paralysis to target muscles In extrapyramidal system: Lesions can exaggerate reflexes Damage to basal ganglia: dyskinesia & Parkinson's, muscle and movement disorders

Future Research

Began in 2006 Synesthesia in Musicians: see music in color Synesthesia and handedness: left handedness Synesthesia and Associative Learning: seeing in two modalities helps remember Benefits of Acquired Synesthesia

1600s and brain dissection

Beginning in the 1600s there began to be major advances in our knowledge of gross brain anatomy. Much of this was done by dissecting animal brains but human brain anatomy was studied as well. Fixatives are the reason why brains turned grey Rembrandt painting of this in 1656, It was necessary to develop methods for preserving the tissue, and to dissect it without damage.

McGarry How Hormones Act Throughout the Body Hippocrates and Aristotle:

Believed that the human body is in balance when a person is healthy. The four body "humors," or fluids, they believed explained our temperament and emotions. Blood, Phlegm, Yellow Bile, and Black bile

Photoreceptor dark vs light Fun Facts!

Dark - photoreceptor depolarized - Neurotransmitter released Light - photoreceptor hyperpolarized - Less Neurotransmitter is released Fun Facts!: -A bird's retina actually has three types of photoreceptors that "translate" light into nervous impulses. (rods, cones, and double cones) -Unlike human retinas, bird's retina contains no blood vessels preventing the shadows and light scattering. -Birds may see more colors than humans and may be able to perceive ultraviolet or near-ultraviolet light. -Butterflies have the widest visual range.

German Physician Arnold Berthold (1803-1861)

Berthold aimed to identify the effects of testosterone in behavior through castration of roosters. Subjects: six castrated roosters (testicles removed) per group Group 1: control group - roosters were kept with their sex organs removed Group 2: the roosters were transplanted with the testicles of another rooster Group 3: the roosters were re-implanted with their own testicles Results: -Group 1: the castrated roosters were less aggressive, less masculine, and had lost their interest towards hens. They had a lesser tendency to crow, fight and mate. They also had smaller comb and wattles. -Group 2 and 3: the roosters that had reacquired testicles behaved normally, as any other un-castrated rooster. Their comb and wattles were both large. Autopsies of the roosters in groups 2 and 3 revealed that the re-implanted testicles did not re-establish nerve connections with the rest of the body. Conclusion: Testicles release a hormone (testosterone) that influences aggression and dominant male behaviors. Berthold was able to identify that a biochemical released by the testes was largely the cause of male characteristics and male behavior. This is because the males that were kept castrated did not show any male specific behaviors and also had lost physical characteristics of male roosters. Note: If Berthold had waited until the roosters were adults to return the testes he would have seen little effect. The testosterone must be present early in life to have such a dramatic effect on the body and behavior.

Different pores for different parts of the neuron C36

Between cell body and dendrites: mostly chemically sensitive (synaptic) pores. Dendrites are where info flows in. Sensitive to neurotransmitters Cell body: mixture of both axon: (almost) only electrically sensitive pores, loaded with electrical and that's how you trigger the spike

Bhardha Circadian Rhythms Types of rhythms (4) The endogenous clock

Biological Rhythms- Regular fluctuations in any living process Circadian Rhythm-A pattern of behavioral, biochemical, or physiological fluctuation that has a 24-hour period Ultradian-a rhythmic biological event with a period shorter than a day, usually from several minutes to several hours long Infradian- a rhythmic biological event with a period longer than a day, could be monthly or yearly The endogenous clock: -Diurnal vs. Nocturnal Humans and other primates are diurnal (awake during the day) Other mammals, mostly rodents, are nocturnal- awake during the night -Circadian activities are very precise

Birth and Labor Pair bonding and Reward

Birth and Labor: -Causes uterine contractions during second and third stages of labor. -Crossing the placenta, maternal oxytocin reaches the fetal brain and induces a switch in the action of neurotransmitter GABA from excitatory to inhibitory on fetal cortical neurons. This silences the fetal brain for the period of delivery and reduces its vulnerability to hypoxic damage Pair bonding and Reward: -It is thought that the prefrontal cortex and Nucleus Accumbens may serve as potential integrative sites for dopamine and oxytocin pathways underlying natural reward circuits and social attachment behaviors governing for example, maternal, and pair bonding

Bitter Umami

Bitter: Members of the T2R family of receptor proteins appear to function as bitter receptors The T2R family has about 30 members Each bitter-sensing taste cell produces most or all of the different types of T2R bitter receptors Umami: Detected by at least two kinds of receptors 1) A variant of the metabotropic glutamate receptor and most likely responds to the amino acid glutamate 2) A combination of T1R1 and T1R3 proteins responds to most of the dietary amino acids

Blindsight history Inducing blindsight Who it's studied in

Blindsight first came to light on the battlefields of the First World War when blinded soldiers were seen to duck bullets even though they had no idea they were doing so. Some degree of blindsight can be induced in people with normal vision by using Transcranial Magnetic Stimulation (TMS) to effectively "turn off" the primary visual cortex (V1). This is the area of the brain where information from the eyes usually impacts first, and starts to be turned into conscious sight. When it is put out of action, people are unable to see in the normal way and report being blind. But in laboratory tests they can still reach for moving objects, correcting the direction of their grasp as they go. Blindsight is more commonly studied, however, in people who are already blind, or partially blind, due to V1 damage.

2/9 Jorgensen Blindsight What is Blindsight?

Blindsight: The paradoxical phenomenon whereby, within a scotoma, a person cannot consciously perceive visual cues but may still be able to make some visual discrimination. People with blindsight say they cannot see, but when asked to guess whether a stimulus is present, they're correct more often than could be expected by chance alone, or they may walk down a corridor strewn with objects without running into them. It is almost as though a fully conscious brain is in telepathic contact with a less conscious one.

2-14 Linares Cortical Processing of Color Brain Regions How the eye processes color

Brain region Vision is processed in the occipital lobe *****Various areas of the occipital lobe are involved in visual processing: -Lateral geniculate nucleus where the info is relayed to V1 -V1, primary visual cortex -V2 -V4, involved in color processing How the eye processes color: -When light enters our eyes special cells tell us about the light. These cells are called photoreceptors. These cells are located in the backs of our retinas, classified as rods or cones. The cones are more responsible for bright light and RGB colors. -The photoreceptors pick up the different wavelengths. -Then signals from the cones transmit to the brain and we perceive them as color. There are about 6 million cones in the human retina.

Three Dimensions of Color Perception

Brightness: -varies from dark to light -Also called lightness or value Hue: -varies continuously through blue, green, yellow, red, etc. -When people use the word "color," they are usually referring to hue -Related to wavelength or dominant wavelength Saturation: -varies from rich, full colors to gray -Also called chroma -Example: red → pink → gray Kachmer SLIDE 11-12 picture

Mid 1800s Brocca's aphasia RECEPTIVE APHASIA Phineas Gage

But in mid 1800s, we began to get firm evidence of brain specialization. Paul Broca EXPRESSIVE APHASIA/BROCA'S APHASIA: Damage to left frontal lobe, Cannot express language correctly, but can perfectly understand RECEPTIVE APHASIA: A few years later, Carl Wernicke found loss of the ability to comprehend spoken language and cannot say anything meaningful back but think they can, Phineas Gage: also became famous, for the accident that damaged his frontal lobes. Rail road worker that had a metal pipe lodged through his brain. The damage was said to affect his "social intellect." Used to be friendly normal then became fits of temper, cursing all the time

Permeability changes

But neurons and muscles have the ability to dramatically increase the permeability of Na+. Sodium channels open for a very brief second of time, then they will close again Sodium is putting pressure on the atoms now and it is the opposite direction, so now the outside is negative. Correct -- the outside is now negative. Otherwise stated, the inside of the cell is now positive. Whether the inside registers as negative or positive is determined by which of the positive ions is more permeable!!! The direction of electron flow depends on which positive ion has greater influence on the electrodes. If potassium is flowing faster it will negative, if sodium it's positive (not many need to flow in to change it)

C29 EPSP IPSP

C29: Thing that is sending the signal is presynaptic ending, vesicles contain neurotransmitter. Target is a postsynaptic element: can be a muscle, cell body, dendrite of a neuron. Sodium channels that open to a transmitter EPSP, excitatory post synaptic potential: The electrical response in the postsynaptic element is not all-or-none -- it varies in size. IPSP, inhibitory post synaptic potential: If the transmitter receptors control potassium channels, the response to spike arrival will be an increase in potassium permeability. There is a hyper polarization of the postsynaptic element. Other kinds of synaptic transmission can produce inhibition as well, such as with chloride cells. In some cases it is very hard to show any membrane potential change and the receiving cell is still inhibited. Or an IPSP can be produced by opening channels that allow chloride ions to enter.

Corpus Callosum Neocortex Ventricles

CC: provides linkage between hemispherres Neo: This is the thin layer of neurons (mostly cell bodies and dendrites) that lies at the outside rim of the brain. V: the fluid chambers of the brain

Cranial Nerves Associated in Taste Processing

CN VII - facial nerve; associated to the processing of taste through a branch of the nerve called the chorda tympani, which is connected to and supports the anterior ⅔ of the tongue CN IX - Glossopharyngeal nerve; connected to and supports the posterior ⅓ of the tongue through the lingual branch CN X - Vagus nerve; the inferior ganglion innervate taste buds in the posterior oral cavity and terminates in the nucleus solitary tract

What is synesthesia?

Can identify backwards numbers very quickly, because they are in a different color than the rest A condition where a stimulus in one sensory modality evokes an additional perception in another sensory modality The stimulation in one sensory pathway leads to an automatic, involuntary response in a second sensory pathway NOT associative learning Thinking about chocolate and tasting chocolate is not synesthesia Inducer (initial stimulus, the number) and concurrent (involuntary response or second modality, the color)

Spectral Sensitivity of Rods and Cones Cones in Human Retina

DIAGRAM ON KACHMER SLIDE 4. Now that we understand the EM spectrum, we can see how the different spectral sensitivities of cones fit in Cones in Human Retina: -Distribution of red (long), green (medium), and short (blue) cones in the living human retina -Images are from two different people, both with normal color vision

Guevedoces  Guevedoces and Changes during Puberty

Caused by a rare genetic mutation where testosterone cannot be converted to DHT. The enzyme (5-alpha-reductase) is disabled, causing no conversion of testosterone into DHT, so the genital epithelium cannot get the androgenic signal amplified where you would have seen the testosterone converted into the more active DHT. XY individual develops testes and normal male internal reproductive structures External genitalia fail to masculinize fully Thus the penis is slightly masculinized and resembles a large clitoris , genital look like a labia but they contain testes. Changes in puberty: -In Dominican Republic many families have this Mutation, and many are regarded as females -Puberty causes the testes to release more androgens and so the external genitalia turns more masculine looking -Penis is small but there, they develop narrow hips and a muscular build , no breast are present. -They being to present themselves as young men and become interested in females.

Vestibular disorders Common symptoms

Caused by aging, injury, or disease Common Symptoms: -Vertigo and Dizziness -Vision disturbance -Hearing changes -Headaches

Cells in Mammalian SCN Molecular Clock

Cells in Mammalian SCN: -Suprachiasmatic nucleus (SCN) 2 proteins: -Clock and Cycle: bind together to form a dimer (pair of proteins attached to each other) -Bind to the cell's DNA to promote the transcription of other genes including per. Molecular Clock: -The molecular clock mechanism involves gene regulatory network composed of transcriptional-translational feedback loop referred to as the core clock. -Comprise the positive arm of the core clock are two members of the PAS-bHLH family of transcription factors Clock (circadian locomotor output control kaput) Bmal 1 (brain muscle arnt-like1) -The disruption of Per1 and Per2 genes together (or cry1 and cry 2 genes) cause behavioral and molecular arrhythmicity.

Central nervous system Peripheral nervous system Somatic nervous system

Central nervous system: brain or spinal cord Peripheral nervous system: all the nerves from everywhere else Somatic nervous system: the sensory and motor nerves can be classified as the "somatic nervous system." Branches come off spinal cord at each vertebra, nerves come in and out of these

Circadian Rhythm Terms Changes to the Rhythm Biological Markers for Circadian Rhythm

Circadian Rhythm Terms: Period-The interval of time between two similar points of successive cycles, such as sunset to sunset. -In the experiment they put two hamsters next to each other in dimly lit rooms -Their periods were independent from each other Phase shift-A shift in the activity of a biological rhythm, typically provided by a synchronizing environmental stimulus. -When the hamsters are re-exposed to periods of light and dark they resynchronize. Changes to the Rhythm: -Entrainment-The process of synchronizing a biological rhythm to an environmental stimulus -Zeitgeber- the stimulus that entrains circadian rhythms. Usually the light-dark cycle Biological Markers for Circadian Rhythm: -Core body temperature minimum. In young adults it occurs near the middle of the 8hr sleep cycle -Melatonin Secreted by the pineal gland. Absent or low-levels during the day

Associations in the brain

Classically, the remaining neocortex was thought to be for associations. But we've seen that vision is more extensive... B35 Also suplemental motor areas, supplemental somatosensory areas Frontal lobe Less and less was being left for memory. But from early on, there was much speculation that frontal lobes mediated learning and memory. Lesion studies in primates show that portions of the frontal lobe are important for learning -- dorsolateral: tasks with a delay -- orbitofrontal: emotional conditioning

Camillo Golgi late 1800s

Colgi stain: - using silver -- showed all the branches of the neurons. The blobs were the open flasks in the textile stain also can follow fibers and discover connections. It even stains the tiny knobs where the endings from other neurons make contact with the stained cell. (dendritic spines)

Color Matching Studies Absorption Spectra

Color Matching Studies: -Individuals alter the relative intensity of 1 to 3 light sources with differing wavelengths to match a monochromatic lower target light -Individuals with normal color vision required 3 wavelengths at all times to complete this task -Participants could not match the colors if they used only two wavelengths, but could match any color in the spectrum if they used three. Absorption Spectra: -Researchers later measured absorption spectra of visual pigments in receptors They found pigments that responded maximally to: -Short wavelengths (420 nm) -Medium wavelengths (530nm) -Long wavelengths (560nm)

Color Problems? Achromatopsia

Color Problems?: -Color blindness -Color agnosia, cannot recognize colors -Color anomia, cannot name colors -Dyschromatopsias, color confusion syndromes -Cerebral achromatopsia, cannot see colors due to brain lesion Achromatopsia: -Patient loses ability to name, sort, or match colors -Lesion in V4 -Sometimes you also get prosopagnosia -Steffan(1988)

Color Vision Dichromatic Color Vision Trichromatic Color Vision

Color vision: -Colors are identified by the brain based upon different opsin responses -Key to color vision ☞ ability to differentiate Dichromatic Color Vision: Only 2/3 primary colors can be discerned. Most mammals have only two kinds of opsins: short and middle which is blue and greens Trichromatic Color Vision: Vision based on the 3 classes of cone photopigments, humans, birds can also see long/red and even ultraviolet (shorter than visible spectrum), some bugs/bees see ultraviolet too

Color Blob, Interblob

Color: -Not limited to only one region In the visual cortex -V4, plays a key role in color processing, most important -V1 & V2, also plays role in color Processing Signal is sent to a pool of neurons in V1 known as a blob : Blob, color processing Interblob, form processing

Synesthesia Genetics

Colored Sequence Synesthesia (CSS) Linkage, Family Study found More prominent in females 23MB region of chromosome 16 Genetics set an individual up for synesthesia Genetic predisposition to synesthesia- role of environment. Under the influence of familial/genetic factors, and mediated by differences in brain structure and brain functioning, synesthetic individuals develop that differ not only in their sensory experiences but also in personal, cognitive and emotional characteristics. Personality, cognition, emotion, and sensory experience varies for all synesthetic individuals Previous genetic and family-based studies have suggested that the biological predisposition is to having synesthesia, not to having particular types of synesthesia ( Barnett et al., 2008, Ward and Simner, 2005 and Bargary and Mitchell, 2008). Putting these findings together, we propose the existence of a general trait of synesthesia. Current results provide the satisfying suggestion that the previously obtained results with one particular type of synesthesia, will be relevant to synesthesia in general, and thus to other types of synesthesia as well. In conclusion, current results show that it is worthwhile to broaden our view on synesthesia, and include the many different types of synesthesia in our models.

Basal Ganglia Disorders Symptoms and Treatment

Communicate heavily with cerebellum SLIDE 8 Parkinson's Disease SLIDE 10: -Degeneration of the dopamine-containing cells in the substantia nigra Symptoms include: slow movement, tremors of the hands and face, a rigid bearing, and diminished facial expressions Treatment: -Based on symptoms -Deep Brain Stimulation(DBS) Uses a surgically implanted neurostimulator to deliver electrical stimulation to certain areas in the brain that control movement which prevents the tremor and other PD symptoms. SLIDE 12 Huntington's chorea slide: -Loss of GABAergic neurons on caudate and putamen (in basal ganglia) Symptoms include: clumsiness, and twitches in stream of involuntary jerks engulf body Treatment: -No treatment QUIZ QUESTION -Adult onset form is slower in its course but it will inevitably lead to death in 14-15 years -The juvenile form has a more rapidly progressive course, with death occurring in 7-8 years

Communication tracts Fissure Convolutions Gyrus Sulcus Nuclei

Communication tracts between the two hemispheres are called commissures Largest one is corpus callosum Bundles of axons are called nerves when they are outside the CNS, but are called tracts when they lie within. Nuclei: small clusters of cell bodies -- especially those which are paired in each hemisphere

Not like computers

Computers use sequences of 1s and 0s for calculation, control operations, and all the amazing things they do. Perhaps because spike pulses are similar to 1s and empty spaces can be thought of as 0s, many have suggested that the brain works like a digital computer. Not so! In almost all computers, information processing goes through a single master control circuit that performs operation on the basis of what combination of 1s and 0s has been provided. So the operations to be performed a controlled by digital messages. Instead, neuron populations send information using parallel fibers, and it is assumed that the kinds of connections that are made among neurons determines the response. The "information" is mainly various degrees of Go and NoGo (excitation and inhibition), not complex message interpretation. It would be more like a computer code if the spikes and spaces between spikes could specify different operations to be performed. Neurophysiologists describe that as "temporal coding theory." Thus far there is minimal evidence that neurons function in this way.

Wolnicki Restoration of Hearing with Cochlear Implants Can you even restore hearing?

Conduction deafness: surgically free up fused ossicles or free up Teflon prosthetic restore the transmission of sound vibrations Sensorimotor deafness: neural elements destroyed or absent from birth. Can new hair cells be grown? YES! Fishes, amphibians, mammal lab animals (recently) Someday regrowth hair cells can be an effective therapy TRADITIONAL: hearing aids detect + amplify sounds to provide extra simulation Only effective for an impaired + still functional auditory system

Cortical Plasticity

Cortical Plasticity - the brain's capacity to change its structure or function in response to experiences, lifestyle and environment TMS (transcranial magnetic stimulation) used on rats -Non-invasive stimulation of cortical neurons -Showed that movements made by an area of M1 changes as a result of repetition or motor learning cortical plasticity -Researchers examined the motor cortex of rats before & after training of a new skill to compare the differences

Cortical Structures Cingulate Cortex

Cortical Structures: -An extensive cortical network constitutes both medial and lateral pain systems -Multiple neurotransmitters, such as opioid, glutamate, GABA, and dopamine are involved in cortical pain modulation -Glial cells may also be involved in cortical modulation of pain for pain management Cingulate Cortex: -Also known as cingulum -A region of medial cerebral cortex that lies dorsal to the corpus callosum -The extent of activation here in the medial pain pathway correlates with the subjective amount of pain people feel. Sewards and Sewards (2002) refer to this as the affective-motivational aspect of pain. -Different subregions seem to mediate emotional versus sensory aspects of pain (Vogt, 2005) -One part of the cingulate cortex becomes active when merely empathizing with a loved one (Singer et al, 2004)

Santiago Ramon y Cajal late 1800s

Curiously, Golgi still argued against cell theory, but his student, Cajal, proved the theory using Golgi stain. The cytoplasm are distinct cells not integrated The two shared the Nobel Prize in 1906

DECUSSATION SLIDE 6 SLIDE 7 SLIDE 8

DECUSSATION -Cell bodies Pass through brainstem and form pyramidal tract to spinal cord -Site of decussation: Point where nerve fibers cross over Slide 7: not all cross over but vast majority do. 2 tracts, lateral cortico spinal tract (70-90% cross over) and anterior cortical spinal tract (10-30% that don't cross over)

Dark ages

Dark ages, with religious prescriptions against autopsies, but still there was grave robbing and doing this Your text shows this painting by Michelangelo, circa 1512, which is on the Ceiling of the Sistine Chapel. Was he secretly dissecting cadavers to study anatomy - in this case, brain anatomy to help his painting/sculptures? This painting Looks like a brain The views of the Greeks (and Galen) persisted up until the 1600s. Images from eyes being carried by fluid into the chambers (ventricles) of the brain. Not accurate. Leonardo da Vinci circa late 1400s Later drawings, based on his own anatomical studies, were more accurate. Could have also dissected Brains to see this and the fluids again were Important in mind, spirit, soul

Charles Sherrington late 1800s

Deduced the existence of the synapse on the basis of 1/2 millisecond delay in transmission. Measured speed of conduction very accurately, synaptic junctions for each neuron hat pass info to each other Mental activity is like weaving a pattern in the rug

In Situ Hybridization Confirmation

Definition: Method for detecting RNA transcripts in tissue sections using nucleotide probe (radioactively labeled nucleic acid lengths) complementary to transcript of interest To search for neurons that make mRNA for steroid receptor which most likely have receptor protein OKINO SLIDE 10 PICTURE Confirmation: -Once brain regions of interest are identified, implantation of small hormone pellets in that area can be used in order to determine whether or not normal function can be restored. -In the case of testosterone, the male sexual behavior in rats was only restored with implants in the medial preoptic area (mPOA) of the hypothalamus.

Immunocytochemistry (ICC)

Definition: Method for detecting specific protein in tissues; antibody used to bind protein and visualization by chemical methods acting on antibodies Allows for mapping of distribution of hormone receptors in the brain by labeling the receptors (unlike autoradiography, which maps movement of hormones rather than their receptors) Leaves dark color in nuclei of target cells (hormone receptors) Fluorescent staining most commonly used (immunofluorescence); FITC and Rhodamine

Autoradiography

Definition: Staining technique showing distribution of labeled radioactive chemicals in tissues Steroid hormones accumulate in nuclei of neurons (leaves small black specks on film); peptide hormone radioactivity accumulates in cell membranes (appear in particular layers of brain) Computer-generated maps of hormone concentration (according to brain region) How is it done? -Inject animal (often with glands removed) with radioactively labeled hormone -Sacrifice animal, remove brain, freeze and slice into thin sections, place on photographic film -Film exposed according to radioactive emissions -Indicates where radioactive hormone has localized OKINO SLIDE 6 Pictures

Descartes mind/body debate Mind brain debate

Descartes provided the basis for a major debate regarding the relation of the mind to the body (and especially the brain). He suggested that some behaviors might be mediated by machine-like processes, certain principles given to species such as the galloping of a horse. Chemical, electrical, all physiology and anatomy. Ex. Reflexes, but did not include higher order mental skills of humans: memories, math, language Mind brain: modern times, his hypothesis is called mind brain debate. Main question: Can all aspects of mental activity be based on mechanistic principles? How about consciousness and free will? *Awareness, higher cognitive skills cannot be mechanistic. Mind body is probably a better explanation

Telephone theory

Developed by Lord Rutherford in the late 1800s after the invention of the telephone. ● He thought that the inner ear might function like a telephone. ● The auditory nerve would conduct a signal to the brain that was a copy of the sound wave, similar to early telephones Theory was developed before it was known that neurons use discrete spikes So the theory became the view that frequency and timing of spikes result in an estimation of a sound wave. ● Scientist Edwin Boring said NO to this theory. ○ We can hear up to 20,00Hz ○ But neurons can only spike at 1000 spikes/sec (max)

Wolnicki Sexual Orientation DEVELOPMENTAL INFLUENCES (2) Nature or Nurture?

Developmental influences 1. Sociocultural influences - instruct developing children about they should behave when they grow up i.e. gender norms 2. Differences @ fetal exposure to testosterone organize developing brains to be attracted to females or males in adulthood. Evidence that early hormones are responsible for some people to ignore societal prescription and become gay Nature or Nurture? -HOMOSEXUALITY provides a TEST for evidence whether hormones are responsible for development of homosexual and heterosexual sexual orientations -Homosexuality (+ other sexual minorities) stigmatized by various social groups + cultural institutions (Herek and McLemore, 2013)

Intensity differences Sound shadow

Differences in loudness at the ears: Slide 14 Causes: One ear is always more directly pointed to a sound Sound shadow caused by the head (slide 15) This shadow blocks off-axis sounds (sounds from one side of the head) Because of this, the ears don't detect equal loudness

Latency differences Two types

Differences in the time of arrival between the two ears One ear is always closer to an off axis sound, that ear is the first to pick up the sound Two types: -Onset disparity- difference between 2 ears in hearing the beginning of a sound -Ongoing phase disparity- mismatch between ears in arrival of peaks and troughs of a sound wave

Restoration of hearing!?

Different from normal hearing Takes time to learn or relearn Earlier in life - better chance at understanding complex sounds later which leads to Success in part is due to the cleverness of the brain -Development speech and language skills -Critical period for brain - learn to interpret sounds Better representation of sounds in the environment -Understand speech -Better focus

Olfactory bulb and odor maps

Different odour molecules are represented by different patterns of spatial activity in the olfactory bulb. And such patterns, analogous to those of other sensory systems, constitute 'odour images', or 'odour maps

Ionotropic receptors

Directly modifying permeability of ions themselves, We have been describing receptors that open to allow ions to flow. Responses of the synapse are thus completely determined by what kind of receptors are present in the postsynaptic membrane. If sodium pores are there, the postsynaptic element will be depolarized, and this is generally excitatory. If chloride or potassium pores are there, the postsynaptic element will be hyperpolarized, and this is generally inhibitory.

Johannes Muller mid 1800s

Doctrine of Specific Nerve Energies: Simply put -- we know what stimulus was presented on the basis of what nerve was stimulated. What nerve is carrying it means what type of sensation it will be. Neuroscientists now call this concept "labeled line theory." It has become a cornerstone principle of the field. He also said it depends on where in the brain it is connected

Drug-Induced Sleepiness Reticular Formation Wakes Up the Brain

Drug-Induced Sleepiness: -GABAA receptors are the same receptors that are stimulated by general anesthetics (drugs such as barbiturates and anesthetic gasses that render people unconscious during surgery) -General anesthetics produce the same slow waves seen in EEG as does SWS -Antihistamines cause sleepiness because histamine is an excitatory NT in the TMN Reticular Formation Wakes Up the Brain: -1916: Baron Constantin von Economo, a Viennese neurologist, began to see patients with a new type of encephalitis that specifically attacked regions of the brain that regulate sleep and wakefulness -Eventually called encephalitis lethargica or von Economo's sleeping sickness -Causes a lesion in the reticular formation, ascending system in the brainstem Late 1940s: scientists discover they could wake sleeping animals by electrically stimulating an extensive region of the brain stem known as the reticular formation -Reticular formation: diffuse group of cells whose axons and dendrites project in many different directions, extending from medulla through the thalamus

Dualism vs Monism

Dualism: There is a nonphysical entity -- mind or soul -- which can and does influence or mediate some activities of the brain. Monism: The activities which we commonly ascribe to the mind are accomplished by brain mechanisms. Neuroscientists tend to do this as professional goals

Synesthesia during Development

During normal development, overlapping neural connections get pruned out by age 4 Some failure to prune in certain areas is believed to cause synesthesia Disinhibition in regions of the brain maintains these connections

Advances in staining -- 1800s

During the 1800s, there were major advances in tissue fixation methods, and learning to enhance the cellular features of tissue by using textile stains. Neuron doctrine: With the microscope, most tissue could be seen to be composed of cells, livers/spleens/etc. Some anatomists argued that the brain also was composed of cells. But many thought not, With textile stains, gray matter had some bodies that could be cells, but others looked like open flasks. Also, there was lots of open space. BUT...

EFFECT OF TESTOSTERONE ON THE SDN-POA EFFECT OF INJECTIONS AT DIFFERENT TIMES

EFFECT OF TESTOSTERONE ON THE SDN-POA: - A normal male rat shows testosterone peak perinatally (just before and around birth) and a second rise at puberty. SDN-POA is large -A normal female rat lacks both the perinatal and pubertal rises in testosterone levels and her SDN-POA is small EFFECT OF INJECTIONS AT DIFFERENT TIMES: -Testosterone can permanently enlarge the SDN-POA in rats, but only if it is given during a sensitive period early in life -A female injected with testosterone at the time of the male perinatal surge develops a large SDN-POA Injections at later times, such as puberty have no effect on the size of a female's SDN-POA

Isolated Brain Still Displays Sleep Cycles

Early studies: animal brain transected Entire brain can be separated from the body by an incision between the medulla and the spinal cord First studied by Belgian physiologist Frederic Bremer in 1938, who called it the "isolated brain" In isolated brain EEGs of animals show periods of wakefulness alternating with periods of sleeping EEG-defined wakefulness: pupils dilated, eyes follow moving objects EEG-defined sleep: pupils were small REM sleep can still be detected in the isolated brain Takeaway: wakefulness, SWS, and REM are all mediated by networks within the brain

Eccentricity & Anatomy Word Acuity & Retinal Eccentricity study

Eccentricity & Anatomy: -Increasing eccentricity means fewer cones and greater rods -Optic disc is a blind spot because it has no visual receptors Word Acuity & Retinal Eccentricity: -Study was done looking at word acuity threshold and retinal eccentricity to determine the rate of threshold alteration in the retinal periphery -Subjects identified words at different eccentricities with 3 different contrast levels Findings: -High-contrast letters had similar thresholds across different eccentric values -Low-contrast letters displayed different threshold change because of eccentricity -Across both contrasts, there was a rapid decline in word acuity greater than 2 degrees of the fovea -Peripheral retina is more dependent on letter contrast

Effect of social influence on the nervous system Why does sexual dimorphism occur?

Effect of social influence on the nervous system: -Example: Development of the SNB -Rat dams (pregnant or parent female rats) spend more time licking the anogenital regions of male pups than of females -The dam's stimulation helps to masculinize his spinal cord -Androgens: The dam identifies male pups by detecting androgen metabolites in their urine -Social influence: The dam treats a pup differently because he's a male, and this differential treatment masculinizes his developing nervous system Why does sexual dimorphism occur?: -Direct product of evolution by natural selection -Struggle for reproduction drives many male and female organisms down different evolutionary paths -Ironically, many forms of dimorphism actually seem to disadvantage organisms Bright coloration of male game birds makes them highly visible targets for predator -Answer to Paradox: At a biological level, the reproductive success of an organism is often more important than its long-term survival.

Electricity

Electrical phenomena were known since the Greeks. Static electricity But in 1700s, methods for generating it were discovered. Metal bottle with glass in between would allow to store charge Some strange experiments were tried. Attempting to return function to a paralyzed limb Above: Electrical shock is applied in an effort to cure mental illness. Below: Recently deceased individuals are shocked in an effort to reanimate them.

A very recent advance - last 10 years

Electrode arrays Electrical activity on each grid electrode is carried to the computer The array records the pattern of electrical activity within a large population of neurons, and how activity spreads over time. Lots of what we know about psychoactive drugs as well as substrates of mental disease has come from the study of the neurochemistry of synaptic transmission. Modern recording of "gross" electrical brain activity has become far more complex, thanks to the ability to do computer processing of the output from each electrode. Newer Research Methods -- fMRI, Positron Emission Tomography (PET), Autoradiography

Hans Berger early 1900s

Electroencephalogram -- EEG Berger was the first to report electrical oscillations from the brain. Different electrical wave lengths for seizures, alert, resting, deep sleep, etc

Encoding tactile Information, receptive fields and coding rate including adaptation Process of encoding tactile information Three types of receptors depending upon the stimulus

Encoding tactile information is quite broad, but it simply means touch. There are many different types of receptors that are used for receiving information in the Somatosensory nervous system. Sensory receptors are found: +skin +skeletal muscles +bones +joints +internal organs +epithelial cells In the central somatosensory system, there are three types of receptors depending upon the stimulus -thermoreceptors-codes for changes in the temperature -mechanoreceptors- touch, vibration, stretch, pressure, etc.. These are the one we look at most in-depth -nociceptors- sensitive to pain, causing stimuli

Hormones are one of several types of chemical communication: Endocrine communication Synaptic communication Pheromone communication Allomone communication

Endocrine communication: the chemical signal is a hormone released into the bloodstream to selectively affect distant target organs. Synaptic communication: communication via synapses. The released chemical signal diffuses a tiny distance across the synaptic cleft and causes a change in the postsynaptic membrane. Pheromone communication: chemicals can be used for communication not only within an individual, but also between individuals. Pheromones are chemicals that are released outside the body to affect other individuals of the same species. Dogs and wolves urinate on landmarks to designate their territory. Allomone communication: some chemical signals are released by members of one species to affect the behavior of individuals of another species. These substances are called allomones. Flowers exude scented allomones to attract insects and birds in order to distribute pollen.

endocrine and nervous system interaction

Endocrine system and nervous system integrate various body systems to provide adaptive responses to the environment For example if sensory system indicates that a stimulus calls for action then hormones can be released to promote appropriate responses There are 4 types of integrative signals between neurons and endocrine cells -Neural-to-neural -Neural-to-endocrine -Endocrine-to-endocrine -Endocrine-to-neural Interactions between the two are cyclic in nature Change in sensation and experience can lead to change in hormone release, which leads to changes in behavior, and these changed in turn lead to changes in experience and so on

Okino Behavioral Endocrinology Techniques Endocrinology Hormones and Behavior Example

Endocrinology: -Definition: A branch of biology and medicine concerned with the endocrine system, including glands, hormones, and diseases that affect the system -Main Purpose: Understanding the system and particularly the roles of each hormone Hormones and Behavior Example: Male rats and testosterone -Observe behavior: Males copulate with receptive females placed in cage -Remove testosterone source (testes) and observe: Eventually stop copulation -Re-introduce hormone (by injection): Males begin copulation again -Knockout organism: individual in which particular gene has been disabled by an experimenter: Knock out the gene for the receptor of the hormone -Observe correlations in hormone level and behavior: Not correlated to blood levels of testosterone Therefore, testosterone is permissive of behavior but not determinant of the level of expression of the behavior.

Estrogens and progesterone secretion regulation

Estrogens act on hypothalamus as well as the anterior pituitary Hypothalamus releases GnRH which acts on the anterior pituitary Anterior pituitary releases LH and FSH -FSH stimulates the growth of ovum containing follicles, triggering the start of the ovulatory cycle -LH stimulates rupture of follicles in the ovary, which releases eggs, leading to the formation of corpora lutea, if the female does not become pregnant the cycle begins again As follicles develop they secrete estrogen which acts on target cells and provides negative feedback on hypothalamus and anterior pituitary Corpus luteum, structure that forms from the collapsed ovarian follicle, causes the release of progesterone which provides negative feedback on the hypothalamus and anterior pituitary and acts on target cells Many oral contraceptives use the negative feedback pathways of estrogens and progestins to inhibit the release of GnRH which prevents ovulation of eggs by the ovary

Interesting information

Even though human male and female appearances are perceived as different, homo sapiens have a low level of sexual dimorphism compared with many other species However, some key differences between men and women: -Hairy vs. not -Big apple vs. small -Square vs. heart-shaped faces

Tonotopic organization

Every level of the auditory system auditory neurons exhibit tonotopic organization, that is they are spatially arranged according to an orderly map of the auditory frequencies to which they tend to respond At higher levels auditory neurons are excited by certain frequencies as well as inhibited by neighboring frequencies leading to a much sharper tuning curve in these areas This allows more precision for discriminating finer differences in sound frequencies Although it is important to note that this doesn't mean that one can know the pitch of a sound based on which neuron was excited

Evidence and problems with temporal coding

Evidence for temporal coding: -Firing neurons on sound waves up to 4,000Hz. -Phase locking PROBLEMS WITH TEMPORAL CODING So, What happens after 4,000Hz?don't know what happens between 4000 and 20,000 Hz A nerve cell cannot signal at 20,000Hz, so temporal code can't be the explanation for conducting at high frequencies. The maximum response rate is about 1,000Hz

Experimental Evidence

Experimental evidence seems to favor the labeled-line system When one taste cell is inactivated, there is a tendency for that specific taste alone to be unperceived while the 4 other tastes are unaffected However, the pattern coding approach can't be ruled out based on this alone because the same example could be viewed as inactivating one-fifths of the pattern of complex activity that is occurring

Johnson Connections of the Eye to the Brain Eye-Brain Connection Optic Chiasm

Eye-Brain Connection: -Visual information is received through the eyes but interpreted with the brain. -Electrical signals are relayed from the retina to the brain via the optic nerve. -The ability to recognize what we see lies in the occipital lobe, near the back of the head. Optic Chiasm: The optic chiasm is an X-shaped space, located in the forebrain, directly in front of the hypothalamus. The left and right optic nerves intersect at the chiasm, thus creating the hallmark X-shape. One-half of each nerve's axons (their long, threadlike portions) enters the opposite tract at this location, making it a partial decussation (crossing). JOHNSON SLIDE 5

Huang Individual Variances in Sleep Requirement Factors

Factors: Age Genetics Varying length of circadian rhythm Faster: morning person "Lark" Slower: night person "Owl" Geography Hot climate: siestas Shorter nighttime sleep Workload Environment Light/dark Medication

Cones

Fast Response Low Amplification Directionally Selective: details are more focused Not Convergent Retinal Pathways Low Sensitivity High Acuity Chromatics, three types of pigments

Inheritence of Sex Chromosomes in Mammals

Female mammals make eggs, which always have an X chromosome. And males make sperm, which can have an X or a Y. Egg and sperm join to make a zygote, which develops into a new offspring. An egg plus an X-containing sperm will make a female offspring, and an egg plus a Y-containing sperm will make a male offspring. Female offspring get an X chromsome from each parent Males get an X from their mother and a Y from their father X chromosomes never pass from father to son Y chromosomes always pass from father to son

Cochlear nucleus

First stage in the auditory system where processing occurs A complex comprised of the dorsal and ventral cochlear nuclei Input is brought to each cochlear nucleus by the cochlear nerve from the ipsilateral cochlea Initial Processing: -In the ventral cochlear nucleus, the timing and pattern in which auditory nerve fibers fire is analyzed -In the dorsal cochlear nucleus, spectral cues along with the location of head, ears, and shoulders are utilized for orienteering responses

Overview of visual system

First step in processing visual information is the optical properties of eye The light energy excites specialized cells in the back of the eye After the light energy is encoded as neural activity it is taken to the cortex Bhada picture slide 3

Luigi Galvani late 1700s

First to propose that activity of nerves and muscles involved intrinsic sources of electricity. Used frogs legs a lot in his studies. Concept became known as "animal electricity." Galvani eliminated sources of fluid pressure, and showed that he could activate the muscle by stimulating the nerve. Yes you can stimulate, but is this how it naturally occurs? Some of his views on "animal electricity came from the study of electric fish. A spark would occur between two metal balls and convince people of biological electricity, the physiology of the animal produces electricity

Zhong Taste Receptors and Taste Sensations Five Basic Chemical Tastes Taste vs. Flavor

Five Basic Chemical Tastes: Sweet, sour, salty, bitter, umami (pleasant savory taste) Taste vs. Flavor: Taste: Any of the five basic sensations detected by the tongue: sweet, salty, sour, bitter, and umami Flavor: Sense of taste combined with the sense of smell

Primary auditory cortex (a1)

Following the medial geniculate nuclei pathways extend to several auditory cortical areas for processing of complex sound from lower auditory pathways Neurons organized according to the sounds they respond to best and neighboring cells respond to neighboring frequencies -Tonotopic organization Damage to this area can result in a loss of ability to recognize songs and voices, essentially the loss of any awareness/ perception of hearing but not necessarily the loss of hearing entirely Still able to react reflexively to sounds due to extensive subcortical processing

Forebrain: Generates Slow Wave Sleep Basal Forebrain

Forebrain: Generates Slow Wave Sleep: -Very different results when Bremer conducted experiments on an isolated forebrain -EEG showed constant SWS, with no wakefulness or REM sleep -Takeaway: SWS is completely controlled by forebrain Basal Forebrain: -SWS in forebrain appears to be generated by the basal forebrain in the ventral frontal lobe and anterior hypothalamus -Electrical stimulation of basal forebrain can induce SWS activity, and lesions of basal forebrain suppress sleep -Neurons in basal forebrain become active at sleep onset and release GABA to stimulate GABAA receptors in tuberomammillary nucleus (TMN) in the posterior hypothalamus Bottom Line: Basal forebrain promotes SWS by releasing GABA into the nearby tuberomammillary nucleus. -If left alone, this system would keep the cortex asleep forever -Brainstem contains a system that arouses the cortex from sleep

Classification of Sensory Systems-Thermal system

Found in dermis, under top layer of skin Detect heat and cold of skin and blood Receptors called thermoreceptors Become pain receptors when extreme heat and cold is present Helps maintain homeostasis Maintain temperature of blood as well

Mechanoreceptors and nociceptors Four types of mechanoreceptors: Free nerve endings

Four types of mechanoreceptors: +Meissner's +Pacinian corpuscles +Merkel's disks +Ruffini corpuscles Mechanoreceptors and nociceptors have different categorizations, but work towards the same goal. More often, the distinction is between control; the touch, joint motion and cognizant movement of the human body. Nociceptors are activated when there is tissue-damaging stimuli and provides an afferent response to CNS Free nerve endings are unspecified response nerve cells that will send afferent information to CNS on temperature

Early 1800s Localization of Mental Function

Franz Joseph Gall Johann Spurzheim Specialization in dif regions of the brain, and could tell the skills of a person by the shape/bumps of the skulls Phrenology: The basic view was that mental faculties were at specific locations in cortex. But they further speculated that the size of skull features indicated the strength of the faculty (or lack thereof). Practitioners of this new "science" sprang up all over Europe and in the United States and self-help books provided instruction on how to determine your own mental traits. As phrenology grew in popularity, it was also the subject of ridicule by scholars and cartoonists. Magendie (critic of phrenology) -- examined the brain of Laplace (brilliant mathematician) and it looked the same as the brain of an idiot

Frequency

Frequency is the number of cycles per second, and is measured in hertz (Hz). For example the musical note "A" has a frequency of 440 Hz: middle "C's" 361.6 Hz. Our perception of frequency is termed pitch. A person with normal hearing, when it comes to pitch, has a range starting low at about 20 Hz. The highest possible frequency heard without discomfort is 20,000 Hz. Our hearing is most sensitive in the 2,000-5,000 Hz frequency range. Most sounds are more complicated than a pure tone. When different instruments play the same note, the notes differ in the relative intensities of the various harmonics; this difference is what gives each instrument its characteristic sound quality or timbre. slide 4

Nonprimary Motor Cortex

Frontal lobe regions adjacent to primary motor cortex that contribute to primary motor control & regulate activity of the primary motor cortex Two main areas: -Supplementary motor area (SMA): initiation of movement sequences; most significant for movements guided by internal plan -Premotor cortex: Activated when motor sequences are guided by external events SLIDE 10 PICTURE Research suggests that...Rather than being a closed and solitary system, the premotor cortex is more likely a collection of different interacting systems therefore controlling different categories of motor behaviors

Fully awake Drowsiness/ pre-stage 1 Stage 1 Stage 2 Stage 3 sWS

Fully awake: Low amplitude waves Fast frequency (>15-20 cycles per second/ Hz) Beta activity Desynchronized EEG Drowsiness/ pre-stage 1 : Beginning of non-REM sleep Frequencies of 8-12 Hz Stage 1: Contains vertex spikes, sharp waves Slowing of heart rate Relaxation of muscles Theta waves Stage 2: Waves of 12-14 Hz Sleep Spindles: 14-18 Hz in EEG of a person in stage 2 K complex: sharp, negative EEG potential Stage 3 sWS: Large amplitude, very slow waves Delta waves SWS- slow wave sleep No longer a 4th stage of sleep

Bhadha Optics of the Eye Introduction to Vision

Function of eye is specific to species -Humans focus on eye preservation Visual information comes in high volume -Filter by important information Species visual ability evolve to match needs -I.e. bat develop night vision Surroundings affect sight

Duke Brain mechanisms for circadian rhythms. Functions Of The Circadian Rhythm The Hypothalamus & Circadian Rhythms Working Around The Clock

Functions Of The Circadian Rhythm: -The standard 24 hour cycle rhythm regulates: sleep/ wake, hormone secretion and metabolism -Disruption consequences: jet lag, genetic disorders, sleep disorders -An irregular circadian rhythm is cause for concern: the most common symptoms are : obesity, cancer and various mental disorders. The Hypothalamus & Circadian Rhythms: -It was discovered that the large legion on the hypothalamus for rats will cause interference with circadian rhythms. -A tiny subregion of the hypothalamus called the suprachiasmatic nucleus (SCN) is located on the optic chiasm and serves as a biological clock. -Severe lesions on the SCN eliminate circadian rhythms of drinking/ locomotion function Working Around The Clock: Experimenters noted that taking SCN cells and putting them into a petri dish shows that they maintain electrical activity and a circadian rhythm for days if not weeks.

Congenital Insensitivity to Pain Ex. Gabby Discovery of this disease

Gabby: -Baby unbothered by minor accidents -Poking herself in the eye, biting her fingers to the bone, she cannot feel pain -Protective gear: goggles, hand restraints -Now a happy, healthy teenager, but she must be extremely careful to avoid injury Discovery: First discovered in 1846. Dr. G Dearborn first reported the condition in 1932 describing Mirin Dajo. Known as "The human pincushion" sword swallowing, put swords through his body, didn't feel anything

Hardin Design of retinal ganglion cells Retinal Ganglion Cells

Ganglion cells are the first neurons in the retina that respond with action potentials. Bipolar cells release glutamate which always depolarizes ganglion cells There are two types of retinal ganglion cells -On-center ganglion cells: depolarize with light -Off-center ganglion cells: depolarize when light is off These fire nerve impulses and report "light" or "dark" to higher visual centers

Evolution of Human Color Vision

Genes for the medium- & long-wavelength pigments occupy adjacent positions on the X chromosome -Are more similar to each other than to the gene for the short-wavelength pigment Primate ancestors believed to have only 1 photopigment gene on the X chromosome that became duplicated -Mutations caused the 2 genes to become increasingly different -Result: different responses to various wavelengths of light Ancestors went from having only 2 cone pigments to 3

Lai Genetics of gender Genetic Components of Sex and Gender Sex chromosome

Genetic Components of Sex and Gender: -Humans are born with 46 chromosomes in 23 pairs. These include 22 pairs of autosomes, which are the chromosomes that are the same in males and females, and one pair of sex chromosomes, or allosomes, which are different in males and females. -The X and Y chromosomes determine a person's sex. Most women are 46XX and most men are 46XY. Sex chromosome: -Unlike the paired autosomes, in which each member normally carries alleles (forms) of the same genes, the paired sex chromosomes do not carry an identical complement of genetic information. -The X chromosome, being larger, carries many more genes than does the Y. -Traits controlled by genes found only on the X chromosome are said to be sex-linked.

Genetic Dissections And Further Info. Recent studies for Circadian Rhythms

Genetic Dissections And Further Info. -By dissecting fruit flies (Drosophila Melanogaster) we were able to understand more about the mammalian circadian cycle. -Cells in the mammalian SCN make two proteins, Clock and cycle, these form a dimer (attached protein pair) 1. Two proteins: clock and cycle, bind together to form a dimer 2. the clock/cycle dimer binds to DNA, enhancing the transcription of the genes for Period and Cryptochrome 3. Per and Cry bund together as a complex that inhibits the activity of the cycle/clock dimer, showing transcription of the per and cry genes and therefore slowing production of the per and cry proteins 4. The per and cry proteins eventually break down releasing the clock/cycle from inhubition and allowing the cycle to start again. The rates of gene transcription protein complex formation, and protein degradation result in a cycle that takes about 24 hrs to complete 5. Retinal ganglion cells detect light with melanopsin and their axons in the retinohypothalamic tract release glutamate onto neurons in SCN. The glutamate stimulation leads to increased transcription of the per gene, synchronizing the molecular clock to the day night cycle Recent studies for Circadian Rhythms: -Chemists and biologists have recently found that circadian rhythms can be altered in chemical methods -The circadian clock rhythm proteins were discovered and named: Clock, Bmal1, PER and CRY.

Genetic Mutation that Specifically Eliminates Pain SCN9A Mutations

Genetic Mutation that Specifically Eliminates Pain: -Mutation in the Sodium channel that is only found in nociceptors: SCN9A -SCN9A: Sodium Voltage-Gated Channel Alpha Subunit 9 Gene that codes for sodium channels -Positioned on long arm of Chromosome 2 -Codes for alpha subunit of NaV1.7 sodium channel SCN9A Mutations: -13 different mutations that have been found to cause CIP -Mutations cause premature stop signal in instructions for making the NaV1.7 alpha subunit (most important area, core of channel) Without this, it impairs transmission of pain signals from injury site to brain -SCN9A gene also codes for sodium channels in olfactory receptors -These mutations can cause anosmia (total loss of sense of smell)

Congenital adrenal hyperplasia (CAH)

Girls are exposed to excess amounts of androgen before birth from the adrenal gland Since the production of androgen in the CAH. Individual is that of normal males and females, the newborn will have an intersex appearance. The penis is intermediate in size between a normal clitoris and a normal penis. A skin fold resembles both a labia and scrotum in CAH individuals. Even with well formed penis and scrotum , no teste may be present inside of the scrotum instead there are normal abdominal ovaries.

Shamamyan Human Gustatory System Processing Taste

Gustatory system - the sensory system that detects taste 5 basic tastes: bitter, salty, sour, sweet, and umami "Gustation, along with olfaction (the sense of smell), is classified as chemoreception because it functions by reacting with molecular chemical compounds in a given substance."

Sensory homunculus

Gyrus: Outer fold/mounds of cortex. Post central gyrus Central sulcus (or fissure): the dipping in part of the brain, deep folds Penfield & Rasmussen, 1950: Canadian surgeon for epileptic patients, open their scalp to have access to brain and stimulate areas until he found the area of the brain that triggered epilepsy. Usually conscious patients. Also found what area of surface of the brain stimulates the body. Called this body map: sensory homunculus

HERITABLE? SCIENCE vs. SOCIETY

HERITABLE?: -Genetic evidence accounts for some, not all, cases: -50% variability in human sexual orientation accounted for by genetic factors, leaving ample room for early social influence -Monozygotic twins (same genes) - do not always have the same orientation (J.M. Bailey et al., 1993) -Non-twin brothers, both homosexual likely to have inherited the same X chromosome region (Xq28 region) from their mother (Hammer et a., 1993) SCIENCE vs. SOCIETY: -Laws and prejudices against homosexuality are based primarily on religious views that homosexuality is a sin that some people "choose" -All homosexual and heterosexual men report from their beginning their interests the romantic attachments matched their adult orientation -No reliable way of changing sexual orientation (Spitzer, 2012) *Most scientists believe that we do not choose our sexual orientation*

HOMOSEXUALITY IN ANIMALS HOMOSEXUALITY IN HUMANS

HOMOSEXUALITY IN ANIMALS: -Homosexual behavior observed in: mountain sheep, swans, gull, sand dolphins (Bagemihl 1999) -(Vasey, 1995) greater complexity of the brain makes homosexual behavior more likely. EVIDENCE: homosexuality more common among apes and monkeys than in proximal primates like lemurs and lorises -(Rosella et al. 2004) difference in the preoptic areia (POA) of "gay" vs. "straight" rams. Refuse to mount females, prefer to mount other rams POA organized by testosterone during fetal development (Roselli and Stromshak, 2009) HOMOSEXUALITY IN HUMANS: LeVay (1991): postmorem examination of POA in humans. 3rd interstitial nucleus of the anterior hypothalamus, or INAH - 3, --Larger in men than in women --Larger in heterosexual men than in homosexual men Brain differences NOT due to AIDS pathology All but one of the gay men in the study had died of AIDS. Straight meant with AIDS had a significantly larger INAH - 3 than did the gay men (Byne et al., 2001) EVIDENCE THAT SEXUAL ORIENTATION IS "BUILT IN"?

Eccentricity in perception Eccentricity and Global Motion Processing

HROVAT Slide 7 Eccentricity and Global Motion Processing: -Motion sensitivity declines as a function of retinal eccentricity -Do changes in motion discrimination performance co-vary with acuity in the retinal periphery? -Global motion- at eccentricities around 16 degrees -Self-motion is bigger because motion patterns present at 25-40 degrees

The Cochlea

Has tonotopic organization, so certain places here certain pitches. TO test: Pitch produced by electrical stimulation @ location in the cochlea approximate the pitch produced by acoustic stimulation Long electrode - stimulation along the length of the cochlea PLACE CODE: von Bekesy Helmholtz

Methods

He dissected a human cochlea, and replaced the fluid with a gel containing coal and aluminum particles that could dance in response to vibrations. He also performed tests on Guinea Pigs. Then bright light was flashed off the basilar membrane during vibration. The displacement of the aluminum was measured to see how much the membrane deformed. slide 12

Hermann von Helmholtz mid to late 1800s

Helmholtz was the first to measure the speed of nerve transmission -- though not with high precision. Of greater important were some of his conceptual developments, which include: -development of the trichromatic theory of color vision (with Thomas Young) -extending Muller's doctrine to explain sub modalities of perception, i.e. how we know the nature of a sensation within a given modality -forcefully arguing that all mental activities can be explained in terms of biological mechanisms

Limbic system

Here are some brain structures often mentioned as involved in control of emotion. orbitofrontal cortex Amygdala Hippocampus Hypothalamus Cingulate cortex

*Na/K pump C 8-9

High concentration of K+ inside the cell and high concentration of Na+ outside the cell, which means there is a concentration differential but there is a firm barrier in the membrane Every cell in the body has enzymes that pump Na+ out of the cell, and K+ into the cell - the Na/K pump. The pump needs ATP for energy to drive the pump The exchange isn't exactly one-for-one, and may not be completely electrically neutral, but this is irrelevant to signal generation. The important outcome is creation of a concentration gradient for each of these positive ions. There are as many negative ions as positive ions on each side of the membrane, so for the present we ignore the negative ions.) Additionally, the membrane is semipermeable to K+, but generally not to Na+. So for most cells, and for neurons at rest, only the K+ is able to run down its concentration gradient.

How we Perceive odors-Odor Coding

How are we able to perceive odors? Cilia contain only one receptor type for each olfactory neuron, while the glomerulus receives information from about 2000 olfactory receptor cells which contain the same type of receptor molecule. Odorants have the ability to bind to several different receptors. Cabral slide 8

How it Works

How it Works: -Hypothalamus acts as regulator and will release these releasing hormones which are then synthesized by neuroendocrine cells that reside in the hypothalamus. -The axons of these cells converge at the median eminence, which is the point at the base of the brain that marks where the pituitary stalk exits the hypothalamus to connect to pituitary gland. PATEL SLIDE 5 DIAGRAM -This area contains the hypothalamic-pituitary portal system, which is an elaborate bed of blood vessels that lead into the anterior pituitary. -After receiving inputs from the rest of the brain, the axon terminals on the neuroendocrine cells secrete their specific releasing hormone into the local bloodstream. -Only goes very short distance into the anterior pituitary. -The speed at which the releasing hormone arrives at the anterior pituitary affects the rate at which the tropic hormones are released. -The tropic hormones are released into general circulation, meaning they can travel throughout the body to reach their target.

Threshold Mechanoreceptors Four types of skin receptor cells called Free nerve endings

However, in order for these sensory cells to be activated, there must be a high enough threshold-or large enough stimulus activity to trigger an action potential. The end receptor and one of the four types of central receptors are mechanoreceptors The form, dimension, edges and complexity of touch is controlled by four types of skin receptor cells called: Meissner's corpuscles (Tactile corpuscles), Ruffini corpuscles, Merkel's disks, and Pacinian corpuscles. Tactile corpuscles for depth perception of objects while Merkel's disks perceive edges. Parcinian corpuscles are in the the lowest layer of skin, the hypodermis and they detect vibration and pressure. Finally, Ruffini corpuscles, also in the hypodermis, detect stretching of the skin when we move our joints/ ligaments. The highest concentration of these can be found in the most sensitive areas: lips, tongue, fingertips. Afferent (carrying info to the brain) Free nerve endings can act as proxy, unspecified thermoreceptors, nociceptors and mechanoreceptors that pick up sensory information. The ability to act in many situations as proxies means they are polymodal. Duke Slide 7

Personality, Cognition, and Synesthesia

Hrovat Slide 12 -Increased intelligence in synesthetes: not specific to any domain, but reinforcing things with two pathways helps to remember things Of the 5 personality traits- -Increased Neuroticism -Increased Openness -Decreased Conscientiousness -More emotional -No observed differences in education level, handedness, age, and sex More emotional but did not have any change in how they expressed their emotion

Auditory System audible range auditory system intensity (amplitude) Frequency

Humans can produce a variety of impressive tones: barely audible murmurs to crescendo vocalizations. This human hearing range is called the audible range. Sound waves are collected in the outer ear, amplified in the middle ear, and converted to neural messages in the inner ear. Auditory system: detects changes in the vibration of air molecules caused by sound sources, sensing both the intensity (amplitude) of sounds (measured in decibels) (dB) and perceived as loudness and their frequency measured in cycles per second or hertz (Hz) and perceived as pitch. We rely on intensity (amplitude) and frequency for communication with others, our safety and transfer of information.

Visual Correction Hyperopia Myopia

Hyperopia (farsightedness)- far objects can be seen but close objects are out of focus As mammals age the lens becomes less elastic Also can be caused by your eyeball being too short Myopia (nearsightedness)- people have trouble seeing objects at a distance but objects up close are in focus Mostly caused by the eyeball being too long so images are focused Also caused by the lens or cornea being too curved and focusing the image prior to the focal point on the retina Myopia with correction: eyeglasses refract the light before it reaches the cornea to bring the image into sharp focus on the retina

Testosterone secretion regulation

Hypothalamus releases Gonadotropin-releasing hormone GnRH travels to and acts on the Anterior Pituitary Anterior Pituitary releases Luteinizing Hormone and Follicle-stimulating hormone FSH acts on receptors in Sertoli cells to govern sperm production LN acts stimulates Leydig cells leading to testosterone production Testosterone acts on Sertoli cells promoting sperm cell production Testosterone and other androgens inhibit the production of GnRH, LH, and FSH in a negative feedback loop. Androgens also act on various target cells developing and maintaining male reproductive organs as well as secondary sex characteristics

What type of nerve endings cause pain

Identifying the nociceptor that detects physical damage is more difficult because so many different chemicals are released by damaged tissue. However, scientists have isolated a mutation in a gene called SCN9A that appears to be responsible for pain insensitivity. SCN9A encodes a sodium channel expressed in many free nerve endings.

Classification of Sensory Systems-Electrical and Magnetic system

Important for other animals like platoipi and sharks Electrical receptors are called electroreceptors They detect the differences in the density of electrical current going through the body, also determine density of current through body and around us and can help regulate it Magnetic receptors are called magneto receptors They detect magnetic fields for orientation

voltage-gated calcium channels Dendrites Dendrite to dendrite communication

In addition to voltage-gated sodium channels, there are also voltage-gated calcium channels that are able to produce spikes. It is not clear under what circumstances for what purposes a given neuron will use this mechanism. Dendrites are usually assumed to have passive conduction of the electrotonic signal, but there is evidence for active conduction using voltage-gated sodium or calcium channels. There is evidence for direct dendrite-to-dendrite communication from reciprocal synaptic contacts, with these interactions providing local responses that can determine or control the perception. This undermines the general belief that such logic operations are done by the neuron, e.g., whether the signal strong enough to generate a spike. Rather, a number of different logic operations may be occurring simultaneously in the branches of the neuron.

The dual olfactory system Olfactory structures in the brain

In the orbitofrontal cortex Brain systems involved in smell perception during orthonasal olfaction Brain systems involved in smell perception during retronasal olfaction (breathing out), with food in the oral cavity. Air flows indicated by dashed and dotted lines; dotted lines indicate air carrying odour molecules. Olfactory structures in the brain: The olfactory cortex is located on the base of the frontal lobe and medial aspect of the temporal lobe.

Myelin

In the peripheral nerves, Schwann cells wrap around the axon, spiral around it forming a membrane (insulation to help speed transmission of spikes) what we call myelin. Fish, mammals, all the vertebrates have myelin axons, invertebrates do not. Junction between schwan cells are nodes of ranvier that transmit signals In the central nervous system, related cells called, Oligodendroglia cells, form same nodes of ranvier, and send out branches, each wrapping a number of axons.

Inferior colliculi

Information from both ears is passed from the ipsilateral superior olivary nuclei, as well as from the contralateral dorsal cochlear nuclei, to the inferior colliculi, the primary auditory structures of the midbrain Paired gray matter structures of the dorsal midbrain, integrates input from several nuclei in the auditory pathway as well as from the auditory cortex Inferior colliculi play an important role in sound localization -Neurons in each colliculi have receptive fields and are activated when sound arrives from a specific region of space

Taste Pathway

Information from taste buds travel to primary gustatory axons Cranial Nerves VII, IX, X carry primary gustatory axons into the brainstem where they then project to the thalamus (Ventral Posterior Medial Nucleus-VPMN) and ultimately project into the primary gustatory cortex The thalamus further integrates the sensory information and relays it to the gustatory cortex

Inhibition of Motor Activity During REM Sleep Do Cats Dream?

Inhibition of Motor Activity During REM Sleep: -One important function of pontine REM sleep center: prevent motor neurons from firing -During REM sleep, GABA and glycine produce powerful IPSPs in spinal motor neurons, preventing them from reaching threshold and producing an action potential -This means that the person's muscles are completely flaccid during REM sleep -Small lesions of particular part of REM center can abolish this loss of muscle tone: this subregion is the area that disables the motor system during REM Do Cats Dream?: -Cats with lesions to this subregion appear to act out their dreams -Enter SWS as they normally would, but when EEG displays signs of REM sleep, instead of going completely limp, they get onto their feet Move their heads as if visually tracking objects that aren't there, bat their forepaws at nothing, and ignore objects that are present -Cat's inner eyelids (translucent nictitating membranes) partially cover their eyes -Appear to be in REM sleep, but motor activity is not being inhibited by the brain -These results suggest that animals dream too

Patel: Auditory system pathway and Brain structures Overall pathway

Input from hair cells is carried to cochlear nuclei Output from left and right cochlear nuclei then extends to each superior olivary nucleus Information is then passed to the inferior colliculi After that output from the inferior colliculi travel to the medial geniculate nuclei of the thalamus From there pathways extend to several auditory cortical areas While this diagram implies that there are relays at each structure, in reality some nerve fibers just pass by slide 10

Intensity/amplitude

Intensity/amplitude of sounds (measured in decibels (dB) and perceived as loudness Amplitude/intensity - is usually measured as sound pressure, or the force that sound exerts per unit area. Our perception of amplitude is termed loudness, expressed as decibels dB. As far as loudness, humans can typically hear starting at 0 dB. A whisper is about 20 decibels and a departing jet airliner a couple of hundred feet overhead is a sound about a million times as intense at 120 dB. 85 dB can be dangerous for your hearing. slide 3: The decibel scale is logarithmic - used for measuring the perceived loudness of sound

Correcting Dichromatic Vision

Introduced a gene carrying a 3rd photopigment into photoreceptors of adult male squirrel monkeys with dichromatic vision Soon displayed excellent trichromatic vision Introduced photopigment genes in mice Also enabled them to discriminate colors they normally cannot see CONCLUSION: it may be possible to correct dichromatic vision in humans!

Watanabe et al., 2013

Investigators conducted a double-blind, placebo-controlled study with 40 high functioning ASD men Subjects were imaged via MRI while performing the "friend or foe" task using 80 stimuli This task involved participants watching a short movie where an actor spoke an emotionally salient word while exhibiting emotional valence in their facial and vocal expressions. Responses to stimuli that were incongruent were classified as non-verbal information-based judgments (NVJ) or verbal information-based judgments (VJ). Ex: The actor might say the word delightful but would have a frown on their face and would say the word with hostility. This would be an example of an NVJ. Behavioral results of this study showed improvements in NVJs as well as decreased response times as a result of intranasal oxytocin administration..

2-7 Presentations Lai Brain areas that process smell Odor-sensing cells Olfactory projections to the brain

It actually shows the key structures mammals use every time they smell. The "mouth" is the nasal cavity of a mouse, which is lined with specialized odor-sensing cells (in green). These cells signal to the olfactory bulbs — the round "eyes" in the image. Lai slide 3

Pain receptors Nociceptors

Jorgensen slide 1 diagram Most tissues of the body contain receptors specialized for detecting painful stimuli. These receptors are particularly well studied in the skin. When tissues are injured, the affected cells release chemicals that activate nearby pain receptors, called nociceptors, on free nerve endings, as well as causing inflammation. Various substances in injured tissue can stimulate the nociceptors - such as serotonin, histamine, and various enzymes and peptides. Different nociceptors respond to various stimuli, such as pain and/or changes in temperature. Can ignore pain through other emotional areas in the brain??

Transient receptor potential (TRP) ion channels A delta fibers C fibers

Jorgensen slide 2 picture Capsaicin is linked to the burning sensation of temperature TRPV1 - reports a rise in temperature to warn us of danger. TRP2 - detects higher temperatures than TRPV1, but it does not respond to capsaicin. Other members of the TRP family of receptors detect coolness. TRP receptors at tip of fiber generating the signal that then travels on the fiber that convey the pain message; they provide the stimulus that generates the spikes. TRP2 receptors are found on A delta (Aδ) fibers, which are small-diameter, myelinated axons. Initial sharp pain you feel from burning your hand TRPV1 receptors, on the other hand, consist of thin, unmyelinated fibers called C fibers. Long delayed pain from a burn

Lateral Geniculate Nucleus (LGN)

Lateral geniculate body, lateral geniculate complex The lateral geniculate nucleus (LGN) is a relay center in the thalamus for the visual pathway. Receives a major sensory input from the retina Is the main central connection for the optic nerve to the occipital lobe Receives information directly from the ascending retinal ganglion cells via the optic tract and from the retinal activating system Neurons of the LGN send their axons through the optic radiation, a direct pathway from the primary visual cortex.

Late 1600s Antoni van Leeuwenhoek 1700

Leeuwenhoek greatly improved the microscope and thus was able to see blood corpuscles, sperm cells, and small creatures -- animalculi -- in sources of drinking water. Also, a cross-section of fresh (unfixed) nerve fibers. Inside the nerve there are axons circa 1700

Ancillary anatomy lens, iris, ciliary muscles

Lens- A structure in the eye that focuses light located immediately behind iris Iris- Ciliary muscles-changes the shape of the lens within the eye. These muscles allow the phenomena of accommodation- which alter focal distance on the eye

Image correction Accommodation Lens and Ciliary muscles

Lens- Transparent layers of tissue used to refract light -Flexible and adjusted by the Ciliary muscles Accommodation: -adjustment of lens called changes the focal distance of the eye depending on distance of object Ciliary Muscles: -Ciliary muscle-a ring shaped muscle attached to the iris and lens -Contraction and relaxation of the muscle affects the lens

"Hearing Colors"

Less than 1% of population Experiencing and associating -Words with taste -Numbers/ letters with color -Pain with shapes -Pain with colors -Sounds with shapes and light -Music with color -Color with sounds Most common association: words and numbers with color 19 forms have been identified

Photoreceptors response to light Rhodopsin

Light particles (quanta/photons) strike a disk where they are captured by photopigment receptor models. The name of this photopigment is rhodopsin. Rhodopsin is in the rods. Rhodopsin-Extremely selective to light, thus it allows vision in low-light conditions. DUKE SLIDE 11

Huang Orientation-selective cells in the primary visual cortex Visual pathway

Light passes through 1) Retina 2) Optic Nerve 3) Lateral Geniculate Nucleus of the Thalamus 4) Primary Visual Cortex

Lordosis Experiment, results, organizational effect

Lordosis: a posture assumed by many female mammals during mating, in which the back is arched downward occurs during the time of ovulation, when her fertility is at its peak. If male mounts at other time, the female will not display lordosis Experiment: Goal: Induce lordosis with ovarian steroids First, injecting the female with estrogen for several days, then progesterone. A few hours after the progesterone injection, the females will display lordosis in response to mounting When female guinea pigs were exposed to testosterone, they did not display lordosis. Even if ovaries were removed. Results: from the data, testicular steroids that masculinized the genetalia during early development also masculinized the developing brain Organizational Effect: steroid hormones permanently organize the nervous system during early development, which is reflected in adult male or female typical behaviors

Frequencies and the binaural cues

Low frequencies- latency differences are the main cues for low frequencies. No intensity differences between ears when sound is presented horizontally around the head High frequencies- sound shadows produce significant intensity differences Extremely low frequencies- neither cue is helpful quiz 6- slide 16

Lucid Dreams Part of brain False Awakenings

Lucid Dreams: Dreamer is aware that he or she is dreaming Control the course of the dream Denotes more conscious thought when compared to typical dreaming In REM (rapid eye movement) dreaming sleep Often super-vivid, high-definition experiences Part of the brain has reactivated (the right dorsolateral prefrontal cortex) False Awakenings: -Vivid and convincing dream about awakening from sleep while the dreamer, in reality, continues to sleep -Usually performing daily morning rituals such as cooking, cleaning, and eating -Highly vivid, suggesting a high level of self-awareness -May occur following a dream or following a lucid dream -Deirdre Barrett: false awakenings and lucidity more likely to occur within the same dream or within different dreams of the same night.

Male reproductive behavior Male Arousal- Vomeronasal Organ (VO)

Male reproductive behavior: The Hypothalamic Medial preoptic area (mPOA) ○ Contains many steroid- sensitive neurons ○ Lesions of the mPOA do not affect male motivation, but does affect their ability to commence reproductive behavior ○ In castrated males, mating can be resetablished by injecting testosterone into the mPOA ○ Mediates reproductive behavior by sending axons to the ventral midbrain and the spinal cord (mediates genital action, such as ejaculation) Male Arousal- Vomeronasal Organ (VO): -Has unique receptor cells near the olfactory epithelium. They detect pheromones that are release by other individuals -Receptors from the VO sent axons to the accessory olfactory bulb and then relays to other parts of the brain to control sex behavior -A target for the VO information is the medial amygdala

Mammal exclusive: Light information reaches the SCN directly

Mammal exclusive: Light information reaches the SCN directly: -Cells in the eye relay to the SCN when it is light outside. -The route that light information takes to the hypothalamus is as follows: retinal ganglion cells send axons along the retinohypothalamic pathway, going out the optic chiasm to synapse within the SCN. -The brain is informed about day length by a secretion of melatonin from the pineal gland. The entrainment pathway consists of specialized retinal ganglion cells containing melanospin that project to the SCN via the retinohypothalamic tract

Measuring Evolutionary Time with Molecular Clock The "Sloppy" Clock

Measuring Evolutionary Time with Molecular Clock: -Estimate Genetic Distance -Use Paleontological Data to Determine Data of common Ancestor -Estimating Calibration Rate (number of genetic changes expected per unit time) -Calculate Time of Divergence for Novel Sequences The "Sloppy" Clock: -'Ticks" are stochastic, not deterministic -Mutations happen randomly according to a Poisson distribution. -Many divergence times can result in the same number of mutations. -Actually over-dispersed Poisson Correlations due to structural constraints.

Medial Amygdala Disorders

Medial Amygdala: The medial amygdala receives information from olfactory and pheromones. ○ Lesions- extinguish erections that would otherwise occur around reproductive females. ○ Will in turn relay information to the mPOA. Therefore, mPOA is important in regulating motor actions for reproductive behavior Disorders: Hypersexuality- An increased desire for sex that negatively impacts an individual's ability to do daily activities Hypoactive Sexual Disorder- Characterized by an individual with low levels for sexual activity

Meissner's Corpuscles Merkel's Discs Ruffini Corpuscles Free Nerve Endings

Meissner's Corpuscles: -They have a low threshold which means they are highly sensitive and detect light touch -They are found more concentrated on the lips and fingers, found in the dermis Merkel's Discs: -They are found in the epidermis (top layer of skin) -They provide information on edges and other types of isolated points on a surface -They also detect deep static pressure placed on the skin. Helps with gripping things as well. Ruffini Corpuscles: -This receptor is used for determining stretching of the skin -It is also used to determine sustained pressure and grip Free Nerve Endings: -Most primitive ending Their axons terminate in the epidermis of the skin -They detect pain, heat, cold, and touch -The sensation for touch is not as accurate and fast as other receptors

Resting membrane potential

Membrane potential, the set up has the ability to create electricity Note that the inside electrode is the source of electrons, i.e., it is the negative electrode. But neurophysiologists like to say that the inside of the cell is negative.** The selective permeability for potassium produces what neurophysiologists call the resting membrane potential At best this is shorthand, though it appears that many experts on the subject believe it is literally true - suggesting , for example, that negative charges are residing on proteins.

Motor Deficits LINARES SLIDE 2 Problems with the Motor Cortex

Motor cortex goes to brain down to spinal cord, cross at the medulla and is important in motor deficits. Depending on where the deficit is it could be contralateral (above the cross) or ipsilateral (below the cross) Problems with the Motor Cortex: -Any lesion in the pyramidal tract will cause paralysis in the muscle targets of the damaged neurons -Upper motor neuron lesions can result from strokes or any other disease affecting motor neurons such as multiple sclerosis or cerebral palsy

How does it work? (5 aspects)

Microphone: picks up sound from environment Sound Processor: captures sound and turns into digital code; Fourier analysis Transmitter: digitally coded sound transmitted from sound processor to implant Receiver/Stimulator: converts the digitally-coded sound into electrical impulses Electrode Array: sends impulses to different regions of auditory nerve

Microvilli

Microvilli - fine fibers that extend from the taste receptor cells into a tiny pore, where they can come into contact with substances that can be tasted (tastants) Each taste cell is sensitive to just one of the five basic tastes Taste cells have a life span of only 10-14 days

Middle Ear So how does it work?

Middle Ear: It is important to note that the oval window (the first window) is a component of the middle ear, while the round window (the second window) is a component of the inner ear. The ossicles are small bones that transmit vibrations from sound across the middle ear. -Incus: hammer -Malleus: anvil -Stapes: stirup So how does it work? Sound waves hit the tympanic membrane, which vibrates at the frequency of the sound, simultaneously vibrating the ossicles (small bones). The ossicles concentrate and amplify the vibrations to be transferred to the oval window, which connects the middle ear and the inner ear. Small muscles, the tensor tympani and the stapedius, attach to the ends of the ossicles and can contract in order to hold the chain of ossicles in place to effectively decrease the "loudness" of a sound in order to protect the inner ear from damage due to loud sounds. slide 6

Molecular Clock in Skeletal Muscle Circadian Rhythm of Molecular Clock

Molecular Clock in Skeletal Muscle: -McCarthy et al found that approximately 35% of all the expressed genes were differentially expressed in the muscle of Clock mutant mice demonstrating the substantial impact disruption of the core clock machinery has on gene expression with implications for normal cellular function and health. Circadian Rhythm of Molecular Clock: -This enables the heart to adapt to various physiological stimuli, which change during the day. -The response of the target for the transcriptional factors involved in regulation of the clock requires determination. -Chronic stress might elucidate disease process mechanisms.

Ferral Molecular Clocking Mechanisms The Molecular Clock Hypothesis Molecular Clock estimations

Molecular Clocking Mechanisms: -Identified in the suprachiasmatic nuclei the master circadian clock mechanism in mammalian brain. -Master clock sets the phase for intrinsic molecular clocks identified in peripheral tissues including the heart. The Molecular Clock Hypothesis: -Stated the amount of genetic difference between sequence is a function of time since separation. -The rate of molecular change is constant (enough) to predict times of divergence. Molecular Clock estimations: -Methods for estimating time under a molecular clock: --Estimating Genetic Distances --Determining and Using Calibration Points --Sources of Error -Rate Heterogeneity -Reliability of time estimates --Reasons for Variation --How its taken into account when estimating times -Estimating gene duplication times

Locus of soul: heart or brain?

Most Greek philosophers accepted the view that the the heart was the seat of the soul, and provide the forces thus creating the source of consciousness, reason and free will. The Roman physician Galen argued in favor of the brain hypothesis, and this became the dominant view for a long period thereafter. If damage brain that's where disabilities came in Brain and ventricles of the brain, fluids also emphasized importance to Carry awareness of information

Grapheme-Color Synesthesia

Most common Emotional brain associations Decreased white matter and Increased grey matter in emotional areas similar to grey matter in synesthetic patients Lower connectivity between thalamus and cortex allowing and promoting other brain connectivity Consistency in color to letter/ number assignment. Letter A will always see red to a certain person, but also could be across people, many people see A as red

Recap

Most hormones are produced by endocrine glands released within the body. 1st major endocrine study was by Arnold Berthold in 1849 using roosters and concluded that testes release a chemical into the bloodstream that affects both male behavior and male body structures. Hormonal communication can be compared with other methods of communication within the human body: Endocrine, Synaptic, Pheromone, Allomone. Hormones can be classified by chemical structure: peptides, amines and steroids.

Hormones can be classified by chemical structure:

Most hormones fall into one of three categories: -Peptide hormones -Amine hormones -Steroid hormones The distinction between peptide or amine hormones and steroid hormones is important because the different types of hormones interact with different types of receptors.

Fundamentals & Harmonics

Most sounds are more than a pure tone. A sound made by a musical instrument contains a fundamental frequency and harmonics. The fundamental is the basic frequency and the harmonics are multiples of the fundamental. If the fundamental is 440Hz, the harmonics are 880, 1320, 1760, and so on (they double). When different instruments play the same note, the notes differ in the relative intensities of the various harmonics: this difference is what gives each instrument its characteristic sound quality, or timbre.

Motor Planning in the sensorimotor system Primary Motor Cortex (AKA "M1")

Motor planning is a process that encompasses the ability to come up with an idea, plan how to complete that idea and execute that idea Primary Motor Cortex (AKA "M1"): -Resides in the frontal lobe, on the precentral gyrus -Precentral gyrus: lies in front of the central sulcus -Organized as a map of body Generates neural impulses that control movement execution. Motor homunculus - body parts drawn in proportion to their significance/size on the M1 map -Body parts we have the most control over amplified on M1 i.e. hands, lips, and tongue -WARNING: M1 map helps understand basic organization of motor cortex, but oversimplifies it. -For instance, it does not illustrate the existing interactions or coordination of different body regions of M1 -Contralateral: Stimulation of specific area of the LEFT side = movement in RIGHT side LEE SLIDE 3 diagram

Ampulla

Movement of the head in one axis directs a flow of liquid into the semicircular canal. This movement deflects the stereo cilia in the ampulla and signals the brain that the head is moving. Utricle & Saccule: contain special receptors that provide the remaining signals - straight-line acceleration and deceleration. Ye slide 4

Past 50 years

Much of what has been learned in the past 50 years has been from single unit recordings. Action potential -- aka spike Extracellular Recordings: fine electrode inside of cell population picking up individual signals/spikes from neurons w an electrode Some has come from intracellular recordings. Getting electrode into the neuron

Types of Synesthesia

Multimodel Synesthesia (92%) Traditional- inducer and concurrent are of different senses Developmental Synesthesia (92%) Condition exists by age 4 Most individuals have more than one type of synesthesia Subtypes: Grapheme-Color Type (86%): letters and numbers are associated with color Chromesthesia (41%): seeing color from a given sound Natural and artificial sounds (33%): bears roar vs artificial sound box roar Ordinal linguistic (62%): specific sounds of words with color

Myth of taste vs the truth Basic tastes and specific sensors:

Myth: Each taste is perceived mainly in one region Truth: All five basic tastes can be perceived anywhere on the tongue where there are taste receptors Basic tastes are signaled by specific sensors on taste cells Salty and sour: taste cells are stimulated by simple ions acting on ion channels in the membranes of the taste cells Sweet and bitter: perceived by specialized receptor molecules and communicated by second messengers Umami: two types of receptors are involved

Nociceptive vs Neuropathic Mixed Category Pain (Other)

Nociceptors in tissues send pain signals to the CNS Neuropathic: damage to the nerve itself causes typical pain symptoms Mixed Category Pain (Other): -Pain that appears to be caused by more complex mixture of nociceptive and neuropathic factors -An initial nervous system dysfunction or injury may trigger the neural release of inflammatory mediators and subsequent neurogenic inflammation -Pain arising from neurological dysfunction, not damage Migraine, nonspecific chronic low back pain, irritable bowel syndrome, fibromyalgia

Diagram on Nociceptive vs Neuropathic vs mixed pain

Nociceptive: caused by activity in neural pathways responsible to potentially tissue damaging stimuli Mixed: caused by a combination of both primary injury and secondary effects Neuropathic: initiated or caused by primary lesion or dsyfunction in the nervous system

Non-hormonal Treatments Issues in Finding Definitive Treatment

Non hormonal treatments: -Mood disorders, neurological disorder, anxiety disorders, substance abuse disorders, impulsivity, etc. are linked to to impulsivity and executive functioning. -Thus, if the symptoms of these are treated with drugs, it would be expected that the same drugs could treat sexual impulsivity and paraphilic behaviors and thus, predation. -Lacking literature and results Issues in Finding Definitive Treatment: -Risk factors are not assessed -Research is lacking well-designed, double-blind experiments with controls -Side effects of hormonal treatments make subjects unwilling to participate -Access to treatments: cost, availability of programs/doctors, etc. Few studies done, no concrete results found yet

Normal Dreams

Normal Dreams: Standard dreams where you have no idea you're dreaming until you wake up Mostly from REM sleep With 8 hours of sleep, you get about 100 minutes of dreaming, with longer and more vivid dreams occurring at the end Insights from the unconscious mind Arrives in the form of conceptual imagery Brain doesn't distinguish between the dream world and the real world. Sequence of events as an alternative reality Possesses no real control over the content of the dream

Causes

Occurs when there is mutation in one of several genes, These mutations lead to deficiencies in 21-hydroxylase or 11-hydroxylase which are enzymes. -95% of CAH symptoms are due to a 21-hydroxylase deficiency -5 % due to 11-hydroxylase deficiency These enzymes are needed by the adrenal cortex to make proper amounts of cortisol, aldosterone, androgens, and Adrenaline. There are two groups, salt wasting and simple virilizing. In the classic CAH , the salt wasting,21-hydroxylase deficiency is severe , and so the adrenal gland makes too little aldosterone there is also too little cortisol and too much androgens. Simple virilizing CAH is the less severe form of classic 21-hydroxylase deficiency, in which there is no severe deficiency of aldosterone , and thus no deficiency in salt, since that hormone helps with salt retention.

Olfactory Receptor Proteins

Odorants will dissolve into mucosal layer and interact with receptor proteins that are on the cilia of olfactory neurons Olfactory receptor proteins are G protein coupled receptors which uses a second messenger system when odorants are detected. There are hundreds, even thousands of subtypes that can exist in a family of odorant receptors - depends on the species Humans make about 350 different kinds of olfactory receptor proteins Cabral slide 6

Chemical analgesic drugs slide 6 picture Alternatives to opiates

Opiates bind to receptors to reduce the pain, descending projections from the spinal cord to block these pain signals. Most effective way to decrease pain systems Morphine Oxycodone Dilaudid Fentenyl Percocet Purpose: bind to receptors to reduce pain Injections directly into the spine: Epidural: right outside CSF Intrathecal: directly into subarachnoid space, usually one time injections, but can get a pump put in under the skin to regulate Alternatives to opiates: Over-the-counter (non-opiate mechanisms): Aspirin Tylenol Marijuana (endogenous cannabinoid receptors) Alt are Not as effective as opiates

Opponent Process Theory Ewald Hering

Opponent process hypothesis- stated that different systems produce opposite responses to the light of wavelengths 4 hues: blue, green, yellow, red and 3 opposed pairs of colors (Blue v Yellow, Green v Red, Black V White) Different physiological processes with opposed positive and negative values are the basis of color vision Cone photoreceptors are linked together to form three opposing color pairs Activation of one member of the pair inhibits activity in the other No two members of a pair can be seen at the same location explains why we don't see objects as "bluish yellow" or "reddish green"

Three most important brain regions for smelling ADD

Orbitofrontal Insula Piriform Cortex

Organizational Effects

Organizational Effects: Steroids have organizational effects only during sensitive periods (early development). Effects tend to be permanent Boundaries for the "sensitive period" depends on which species is being examined. -Rats: androgens given just after birth can affect later behavior -Guinea pigs: must be exposed to androgens before birth for adult lordosis to be affected.

Organizational hypothesis Conclusion

Organizational-Activational Hypothesis: states that for all sexual differentiation there is a single steroid signal (androgens) that diffuse through all tissues and masculines the body, brain, and behavior, if the nervous system does not detect androgens, its will organize itself mostly in a female fashion Conclusion: Complete masculine behavior requires androgens both during development (to organize the nervous system) and in adulthood (to activate that behavior) Conclusion: animals exposed to androgens early in life behave like males, whereas animals not exposed to androgens behave as females

Impairments from sleep deprivation

Our mental function is impaired when we go without sleep - this is a problem for college students who rarely get enough sleep, just when they are supposed to be learning how to make their way in the world on their own. Early reports from sleep deprivation studies emphasized a similarity between schizophrenia and "bizarre" behavior provoked by sleep deprivation; dreams were seen as a "guardian of sanity." This idea was quickly shot down after examination of patients suffering from schizophrenia. They can show sleep-waking cycles similar to those of typical adults, and sleep deprivation does not exacerbate their symptoms. Although some participants in a study on sleep deprivation showed occasional hallucinations, the most common behavior changes were increases in irritability, difficulty in concentrating, and episodes of disorientation. It is clear that prolonged, total sleep deprivation in mammals compromises the immune system and can even lead to death! Although some people seem to need very little sleep, most of us feel the need to get 7-8 hours a night.

Papillae Taste buds

Papillae are tiny lumps of tissue that increase the surface area of the tongue There are three kinds of taste papillae - circumvallate -foliate -fungiform papillae Occurring in different locations on the tongue ZHONG slide 4 Taste buds: Taste buds - a cluster of 50-150 taste receptor cells Buried within the walls of the papillae A single papilla may house many taste buds

Ovulation Proceptive behaviors

Ovulation: -Ovulation - the production and release of an egg -Similar to female humans, female rats ovulate spontaneously -meaning they ovulate even when left alone -Around the time of ovulation, female rats lure in males with proceptive behaviors (i.e high frequency vocalizations) Proceptive behaviors: -Three components of proceptive behaviors: -Approach-female approaches the male -Orientation- female positions self in a way that allows the male to sniff and groom her anogenital region -Runaway-female hops away from the male, prompting him to chase her

Interesting effects of Oxytocin

Oxytocin therapy increased emotional recognition in children suffering from autism. (Guastella et al., 2010) Oxytocin can mediate wound healing by decreasing inflammation by decreasing certain cytokines (Gouin et al., 2010) Oxytocin reduces fear by inhibiting the amygdala. (Kirsch et al., 2005) Oxytocin can increase levels of trust (Lane et al., 2013) Oxytocin promotes learning and memory for socially relevant information (Guastella et al., 2008) Increased male memory for happy faces

Neuroendocrine Signaling oxytocin and vasopressin

Oxytocin: -Plays a large role in Pair Bonding (perhaps more so in females) -Milk Let-down reflex -Orgasm -Birth -Maternal Bonding Vasopressin ADH -Induces water retention in kidneys -Raises blood pressure by vasoconstriction -Pair-Bonding in Prairie Voles

Sensory Transduction-Pacinian corpuscle Transduction of Stimuli- Threshold

Pacinian corpuscle: Onion like structure located in the hypo dermis Detects vibration (usually 200 beats per second) and pressure Stimuli stretch the nerve ending and allow the sodium channels to open and produce a generator potential Transduction of Stimuli- Threshold Threshold is the amount of stimulus needed to create an action potential This means you can have a stimulus but no action potential to notify our body because it did not reach the threshold If the firing threshold is met then the action potential is sent to spinal cord.

Neuropathic

Pain initiated or caused by a primary lesion or disease in the somatosensory nerve system Sensory abnormalities range from deficits perceived as numbness to hypersensitivity (hyperalgesia or allodynia), and to paresthesias such as tingling. The result of an injury or malfunction in the peripheral or central nervous system, often triggered by an injury, but this injury may or may not involve actual damage to the nervous system Diabetic Peripheral Neuropathy Slide 8, shingles, reflex sympathetic distrophy, spinal cord injury pain, phantom limb pain

The Dimensions of Pain What is Pain?

Pain is a physical suffering or discomfort caused by illness or injury "Usually localized physical suffering associated with bodily disorder (as a disease or an injury); a basic bodily sensation induced by a noxious stimulus, received by naked nerve endings, characterized by physical discomfort (as pricking, throbbing, or aching), and typically leading to evasive action (the pain of a bee sting)

Extrapyramidal system KUMAR SLIDE 10 diagram

Pathways for coordination of movement and control posture and muscle tone Controls more gross movements and facial expressions All motor pathways not part of the pyramidal system, including basal ganglia (above brain stem) Cortex can influence this system via inputs to brain stem Rebrospinal: sskeletal muscle Reticular spinal: autonomic functions Techtospinal: neck muscle functions Vestibulospinal: balance

Placebo Effect acupuncture

Placebo Effect: Wisdom teeth extraction study -Morphine or Placebo -1/3 placebo patients experienced pain relief BUT When given naloxone (blocks opioid receptors), there are no placebo effect. Placebo effect itself makes use of brain's pain control system Likely activates brain's endogenous opioid system (endorphins, enkephalins, dynorphins) Acupuncture: Minority actually experience pain relief Similar to placebo effect Release of endorphins. One type of endogenous opioid Benefits of acupuncture can be blocked by naloxone

Spectral filtering

Process by which the hills and valleys of the external ear alter the amplitudes of some frequencies in a sound but diminish others The structure of the external ear and pinna act as localization cues Angle that the sound arrives at peaks and valleys determine the frequencies that are affected Spectral cues help decide what vertical localization (or elevation) a sound came from Without these spectral cues, you wouldn't be able to tell if a sound was coming from the ground or a tree

The ovaries

Produces mature female gametes, ova or eggs, and sex steroid hormones Unlike in the testes hormone production in the ovaries occurs in cycles -Human ovarian cycle ~ 4 weeks -Rat cycle ~ 4 days Produce two major classes of steroid hormones -Progestins like progesterone. Involved in pregnancy, preparation of uterine wall for implantation of a fertilized egg and preparation for milk secretion -Estrogens like estradiol. Promotes the development and maintenance of female reproductive organs. Promotes development of female secondary sex characteristics

Proof of SCN power: transplantations

Proof of SCN power: transplantations: Ralph and Menaker (1988 et al.) -Researchers found a male rat with a 22 hour rhythm. 50% of offspring also had a shorter cycle—20 hours- showing there is a genetic component to SCN and cell deficiencies. -More evidence for the SCN masterclock: endogenous transplants gave comparable results of the donor SCN meaning the SCN MUST be driving the circadian rhythms. Results: When the adult hamster recovered, it did not show its original circadian rhythm of about 24 hours, but displayed a rhythm that matched that of its donor, about 20 hours Conclusion: Within the SCN itself there must be a mechanism that can drive a circadian rhythym in activity, and this biological clock is affected by mutation of the gene tau

Pyramidal system KUMAR SLIDE 4 diagram

Pyramidal system: Pathways for voluntary movement and fine movements Pyramidal cells in the primary motor cortex Neurons originate in the pRE-central gyrus or primary motor cortex

Recap

Pyramidal system=direct activation pathway, this pathway dominated Voluntary muscles for neck, head, and limbs Lateral corticospinal and ventral corticospinal tracts Extrapyramidal system=indirect activation pathway. Probably came first Main pathway for voluntary movement Basal ganglia modifies impulses

Quanta / Photons Rhodopsin (visual purple) FERRAL slide 6 Photochemistry of Vision

Quanta / Photons Light particles that strike the disc and are captured by special photopigment receptor molecules Rhodopsin (visual purple) The photopigment in rods that responds to light. Photochemistry of Vision: Rods -Sensitive to dim light -Made up of glycoprotein opsin -Derivative of Vitamin A (retinals) Cones -Sensitive to color / details

REM sleep Sleep cycling

REM sleep: Very abruptly enters REM Small amplitude, high frequency activity Eyes darting rapidly in the lids Atonia- complete absence of muscle tone Paradoxical sleep Vivid dreaming Sleep cycling: Average sleep time for young adults: 7-8 hours Cycles last 90-110 minutes Typically repeat 3-4 cycles per night

Classification of Sensory Systems-Mechanical system

Receives input for: -Touch -Hearing: hit hammer ear drum, then those are what shape liquid in the cochelea, vibrates then the little hairs which let you hear -Vestibular(balance): sterocylia, helps sense what direction your body is, balance -Muscles -Joints Receptors called Mechanoreceptors

Receptive fields Somatosensory receptive fields

Receptive field definition: Stimulus region and features affecting the activity of a cell in a sensory system. Receptive fields differ in size/ shape and stimulation quality-meaning- power necessary to trigger activation. The research done on receptive fields often tests a variety of stimuli to see what makes A cell go from a resting rate to action potential state. Somatosensory receptive fields are donut shaped that contain an excitatory center and inhibitory surround or vice versa. These spots are also know as ON-OFF switches; ON for excitatory and OFF for inhibitory. These receptive fields have also been identified in the auditory system and visual system The responses from the cells can be recorded and shown in periods of stimulation. Touching outside receptive field yields one tick or minimal activity. Stimulation on the inhibitory portion of the receptive cell, the OFF area yields absolutely no ticks. Stimulation on the excitatory portion (ON) yields many ticks-a lot of response.

Retinal Ganglion Cells and Receptive Fields Think of receptive fields as

Receptive fields of a sensory cell consists of the stimulus region and the features that excite or inhibit the cell In animal studies, it has been found that retinal ganglion cells are concentric with a ring around it, which is usually referred to as the surround Think of receptive fields as: -The piece of the retina/photoreceptors that connects (indirectly) to the ganglion cell, or -The region of the visual field in which light stimuli evoke responses in the ganglion cell.

Recombination and Sex-Linked Genes Human Sex Differentiation

Recombination and Sex-Linked Genes: -When gametes (egg and sperm) form, chromosomes go through a process called recombination. During recombination, homologous chromosomes pair up and exchange stretches of DNA. Recombination makes new allele combinations, which can then be passed to offspring. -When sex chromosomes don't have a homologue (XY male mammals and ZW female birds, for instance), the sex chromosomes do not recombine. Instead, the sex chromosomes pass unchanged from parent to offspring. Human Sex Differentiation: -The presence of a Y chromosome determines sex. Presumably, this region had been transferred to the X chromosome during a translocation (Page et al., 1985). Subsequent experiments narrowed down this region (McLaren, 1991) and found that one gene, the sex-determining region of the Y, or SRY, was the master regulator of sex determination. -In human embryos, the SRY gene encodes a unique transcription factor that activates a testis-forming pathway at about week seven of development. Before this time, the embryonic gonad is "indifferent," meaning that it is capable of developing into either a testis or an ovary.

Reproductive Process

Reproductive Process: -The proceptive behaviors of the female results in the male mounting her -If the female is accepting of the mate she gets in a position referred to as lordosis -Lordosis-the hind quarters are raised and the tail is turned to one side to allow intercourse -The male then makes one single thrust then jumps off the female: this happens 7-9 more times during the next 6-7 minutes -During the final thrust, rather than jumping off, the male raises the front half of his body to ejaculate -The rats then groom their own genatalia for about 5 minutes -After this the female usually engages in more proceptive behavior and the two repeat the process -Rats may engage in 5-6 cycles of intercourse in one mating season

Criticism with grandmother cell theory

Requires a vast number of cells Faces must be recognized from various angles Doesn't respond to specific facial features Only responds to the face as a whole

ASD and the Amygdala

Research by Kim Dalton on gaze fixation patterns of ASD individuals has shown that decreased incidence of fixation on emotionally salient facial features (eyes) was correlated with hypersensitivity of the amygdala Her data can be interpreted as such: ASD individuals may experience a heightened emotional response associated with gaze fixation as a result of increased amygdalar responsiveness This helps to explain why many ASD individuals do not engage in much eye contact, it is likely aversive to them. If oxytocin administration in ASD individuals can decrease the responsiveness of the amygdala, perhaps this could increase the period ASD patients could spend in gaze fixation.

Evidence Afterimages

Researchers performing single-cell recordings found opponent neurons in 1970s Opponent neurons: -Are located in the retina and lateral geniculate nucleus -Respond in an excitatory manner to one end of the spectrum and an inhibitory manner to the other Afterimages: -Opponent process theory explains negative afterimages -If one member of a color pair is "fatigued" because of long periods of observance, the corresponding member's inhibition is reduced -Increases the relative activity level of other member and is perceived more strongly

Arm Movements of Monkeys

Researchers recorded M1 neurons in monkeys while they made arm movements Found that... -Many M1 cells change firing rates according to direction of movement, but for any of the cells, the firing rate was HIGHEST in ONE particular direction Could predict the direction of the monkey's arm movement by averaging activity of 100s of M1 neurons at once

Results Puberty

Results: -Females exposed to testosterone at birth, reduces the lordosis response -Males exposed to estrogen and progesterone at birth, show little lordosis response. -Castrated males exposed to estrogen and progesterone do show resoponse Puberty: -In mammals: puberty is viewed as a second sensitive period -Steroid exposure during puberty causes the addition of new cells to sex-related brain regions

Results

Results: -Some evidence shows that those who were treated with antiandrogens had lower rates of reoffending compared to those who did not receive the treatment, as well as decreased sexual arousal when stimulated with offense-specific stimuli. -Self report -Other evidence shows those who were treated with the hormonal agents had similar rates of reoffending -Lacking well designed, controlled experiments

Reticular Activating System The Pons Triggers REM Sleep

Reticular Activating System: -Electrical stimulation anywhere in along this reticular formation produces wakefulness -Sometimes called the reticular activating system (RAS) of the brainstem -Lesions of these regions produced persistent sleep in animals -Bottom Line: basal forebrain region actively imposes SWS on the brain, and the brainstem reticular formation pushes the brain from SWS to wakefulness The Pons Triggers REM Sleep: -Lesions of the region just ventral to the locus coeruleus abolish REM sleep -Locus coeruleus: Small modulatory nucleus in brainstem whose neurons produce epinephrine and norepinephrine -Electrical or pharmacological stimulation of this same region can induce or prolong REM sleep -Some neurons in this region seem to be active only during REM sleep

Visual processing in the retina 4 steps

Rod and cone photoreceptors release neurotransmitter molecules into synapses on the bipolar cells Bipolar cells connect with ganglion cells-> axons of the ganglion cells form the optic nerve -> afferent response to the brain Horizontal cells-make contact with receptors cells and bipolar cells. Amacrine cells-contact both bipolar and ganglion cells

Manipulating Oxytocin and Vasopressin

Rodents given supplementary amounts of Oxytocin spend more time in physical contact (Carter, 1992) Male mice with Oxytocin gene knocked out display 'social amnesia' (Ferguson et al., 2000) In Prairie Voles monogamous bonding was a result of Oxytocin release in females Vasopressin was shown to be responsible for male monogamous bonding Conversely, Meadow voles are polygamous and display far lower concentration of Vasopressin receptors in some brain regions than Prairie Voles (Lim et al., 2004) Giving virgin sheep mothers Oxytocin causes maternal bonding with unknown offspring (Kendrick, 2004)

Ferral Photochemistry of Rods & Cones Rods & Cones

Rods and cones structure when magnified look like large stack of membranous pancakes Light is reflected in many directions and only a fraction of light that strikes the cornea actually reaches the retina. This stacking of the discs increases the probability that they will capture light particles that will reach the retina. Feral SLIDE 3: A flash can be exceptionally short and still produce the prolonged "general potential" a flash can even last one microsecond (millionth of a second). The response depends on the number of photons that were delivered by the flash, not the duration, so as the flash is made shorter, it must commensurately brighter. This duration is likely a invertebrate retina. Primate cones and rods are closer to 60-70 ms.

Lee Dichromatic Color Vision in Mammals Review of rods, cones, and opsin

Rods: -Sensitive to dim light -Unable to detect color Cones: -Only function in sufficient, bright light -Provide sharper images -Detect color Opsins: -Light sensitive pigments -Near surface of cones -Opsins in different cones are sensitive to different wavelengths of light

Rods position and shape How the Eyes Work with Intensity Changes?

Rods: Retinal fits against the opsin. It has a bent shape when in the dark and is known as the cis retinal. How the Eyes Work with Intensity Changes?: -Pupil: the opening formed by the iris that allows the light to enter the eye. -Adjusting the size of the pupil -Iris: colorful circular structure/disc of the eye that provides the opening the the pupil

Role of extrapyramidal tract Extrapyramidal system/indirect activation pathway

Role: selective activation Initiation setting rate coordinating Extrapyramidal system/indirect activation pathway: -Starts in cortex and influences lower motor neurons -Axons run from forebrain to brainstem to spinal cord -Projections pass through spinal cord through specialized motor regions -Polysynaptic

Salty Sour Sweet

Salty: Sodium ions (Na+) enter taste cells via sodium channels in the cell membrane A second salt sensor, TRPV1, gives us a bit of extra sensitivity to Na+ Sour: Acids in food taste sour, but researches don't know how sour tastants are detected Researchers believe that the protons (H+) that all acids release may interact with special acid-sensing ion channels Sweet: These receptors are made up of simpler proteins belonging to two families - designated T1R and T2R - that are combined in various ways When two members of the T1R family - T1R2 and T1R3 combine, they make a receptor that selectively detects sweet tastants

Discovery of selective cells in V1 study

Sedated cat looks at screen Electrodes hooked up to V1 Images are displayed on screen Action Potentials are measured for a particular cell This cell has a preference for a certain orientation (thus named orientation-selective cells). SO the vertical line produced many more action potentials than a horizontal line Also called edge detectors because they detect the edge of the visual stimulus

Dimensions of Pain

Sensory Discriminative: -Processing in the primary and secondary somatosensory cortex -the perceived intensity, location, and quality of painful stimuli Affective Motivational: -Usually involves processing in anterior cingulate cortex , insular cortex, and prefrontal cortex. -Reflects the perceived unpleasantness of a painful event

Adaptation in Neuroscience

Sensory adaptation: Progressive loss of receptor response as Stimulation is maintained. The initial stimulus whether is be weak, Moderate or Strong causes rapid neuron firing, yet that peters off As adaptation occurs. Firing at high rate: the intensity of a stimulus is determined on firing rate. High rate=high stimulus intensity Firing at low rate= low stimulus intensity

Spinal cord

Sensory information from the body is transmitted over nerve fibers into the spinal cord. Some of the input is used to coordinate local reflexes. Reflex: single loop from central neuron, to motor neuron to muscle. Reflexes can be more complicated though with several points on spinal cord or even up to brain stem Fibers from different zones of the body enter along the length of the spinal cord. Dorsal roots Ventral roots Vertebrae

Drug Induced Synesthesia

Serotonergic hyperactivity theory: some sort of area in the brain is responding to an increase in serotonin, strengthening these sensory networks. Where cells are dying, these areas are being filled with serotonin and glutamate which make excitatory pathways -Psychedelic drugs- psilocybin (shrooms), LSD (acid), mescaline (mescal) -Excessive serotonin -Severe brain injury -Glutamate and serotonin flood areas with dead cells -Large levels of serotonin increases excitability and connectedness of certain brain regions

The testes

Sertoli cells produce male gametes, sperm cells Leydig cells produce and secrete testosterone, an androgen Testosterone -Controls bodily changes such as hair growth, genital size, and changes in voice -In animals that are seasonal breeders, testosterone has pronounced effects on appearance and behavior. For example in certain species of deer testosterone affects the development and strengthening of bone tissue in antlers and fighting between males -Levels tend to decline with age

Short vs. Long Sleepers

Short sleepers -1-5% of population -Require 4-6 hours of sleep/night -Energetic/Active -Optimistic -Work Hard; Keep busy -Confident -Adept -Decisive -Satisfied with themselves/their lives Long Sleepers -6-10% of population -Require 9+ hours of sleep/night -"Worriers" -Mildly depressed/anxious -Less easily definable

Action potential aka Spike

Signals from individual neurons can be made using extracellular recording, also known as single- unit recording The brief pulse provides the basic signal that carries information or elicits action. Can also put this into a speaker and you hear a pop and those are the spikes being generated by the neuron

Dermatones

Skin zones are served by different nerve roots, and goes to different vertebrae areas of the spinal cord Certain overlap of the skin zones with vertebraes Primary somatosensory cortex: one neuron the information is relayed to cortex, S1 completely contralateral to the sensory input Sensory info from left side of body is carried to right brain and vice versa, decasation?: the crossing over of sensory output Commissures: Crossing over of info from one side of brain to another Thalamus: carries sensory info from every modality and passes to cortex

Kachmer Brain Systems Related to Sleep and Dreaming Sleep Stages Four Interacting Neural Systems

Sleep Stages: -Sleep was once regarded as a passive state, as if most of the brain stopped working while we slept -We now know that sleep is an active state Four Interacting Neural Systems: 1. Forebrain system stimulates slow wave sleep 2. Brainstem system activates the sleeping forebrain into wakefulness 3. Pontine systems triggers REM sleep 4. Hypothalamic system coordinates the other three brain systems to determine which state we're in

Sleep apnea Sleeping Drugs

Sleep apnea: -Breathing ceases or alarmingly slows momentarily; blood levels of oxygen drop excessively -Arises from either... -progressive relaxation of muscles of chest, diaphragm, and throat cavity -Self-choking -More common in obese people -From changes in pacemaker respiratory neurons of the brainstem -Frequently accompanied by loud, interrupted snoring -Speculation in causing SIDS (sudden infant death syndrome) due to immature respiratory systems Sleeping Drugs: -Ancient Greeks used opium from poppy and products of mandrake plant to aid sleep -Benzodiazepines and nonbenzodiazepine sedatives bind to GABA receptors, stimulating drowsiness/relaxation and inducing sleep -GABA receptors— a group of receptors (in human brains) that respond to GABA, a neurotransmitter primarily responsible for inhibiting the function of the nervous system -In research study done by Lance P. Longo and Brian Johnson... Found that benzodiazepines may be very addictive for patients with a history of substance abuse/addiction

Somatosensory Routes & Mapping onto Cortex Somatosensory Pathways

Tactile information The cell bodies of the neurons are located in the dorsal root ganglion, the spinal cord, and the thalamus. The major target is the postcentral gyrus.

Sleep conserves energy Sleep enforces niche adaption

Sleep conserves energy: -During sleep there is diminished metabolic activity -Reduced muscular tension -Lowered heart rate -Reduced blood pressure -Reduced body temperature -Slower respiration -However, energy savings from sleep are modest at best Sleep enforces niche adaption: -Ecological niche: the unique assortment of environmental opportunities and challenges to which each organism is adapted -Through the specialization of diurnal or nocturnal vision, this niche adaption is reinforced -Based on their sleep specialization, animals are better adapted to gather food, avoid predators, etc. during their respective wake period -Natural selection probably played a role in this

Hardin The Biological Function of Sleep Sleep is vital Four Functions of Sleep

Sleep is vital: We spend about 1/3 of our lifetime asleep It is not possible to survive without sleep, but scientists are still unsure why exactly that is However, science has ascribed four functions that are vital to why sleeping is so important Four Functions of Sleep: Sleep conserves energy Sleep enforces niche adaption Sleep restores the body and brain Sleep may aid in memory consolidation

Sleep recovery

Sleep recovery - the process of sleeping more than normally after a period of sleep deprivation, as though in compensation. Studies of sleep recovery show that in the first night of sleep recovery, stage 3 sleep shows the greatest relative difference from normal. This increase in stage 3 sleep is usually at the expense of stage 2 sleep. However, the added stage 3 sleep during recovery never completely makes up for the deficit accumulated over the deprivation period. Which is why people say there is no such thing as "catching up on sleep." REM sleep in recovery nights is more intense than normal, with a greater number of rapid eye movements per period of time. So you never recover all the sleep time you lost, but you may make up for the loss by having more intense sleep for awhile.

Sleep restores the body and brain Sleep deprivation

Sleep restores the body and brain: -One of the proposed functions of sleep is simply the rebuilding or restoration of materials used during waking -Sleep may also "clean out" the brain The flow of cerebrospinal fluid is faster during sleep, and the flow of this fluid collects and disposes of toxins that build up (Xie et al., 2013) -In fact, the body is extremely affected when one goes through prolonged sleep deprivation Sleep deprivation: -Mild deprivation such as sleep disruption or shortened sleep, makes people more sensitive to pain the following day (Edwards et al., 2009) -In rats, prolonged and total sleep deprivation, interferes with the immune system and eventually lead to death -One study found that sleeping less than 6 hours per night were more likely to die over the next 6 years, but also people who slept more than 8 hours per night were also at greater risk (Gangwisch et al., 2007)

Sleeping and Memory Myth What about people who sleep very little?

Sleeping and Memory Myth: -We all have heard the myth that you can play a recording, listen to it in your sleep, and you'll subconsciously learn the material -This is a MYTH. The brain refuses to store anything during REM sleep, therefore you cannot learn new material while you sleep -The only way this will work is if you stay awake to listen to it (Wood et al., 1992) What about people who sleep very little? -A Stanford professor slept only 3-4 hours per night for more than 50 years and lived to be 80 (Dement, 1974) -A study conducted was conducted on a 70 year old nurse who had 23 hours of wakefulness Never complained about being tired Her sleep was recorded for 5 days, and she slept an average of 67 minutes per night Could be genetics or that she was a more efficient sleeper than the average person -No healthy person has been found to live without sleep

PICTURE OF BLINDSIGHT DIAGRAM Can Blindsight be considered a special case of Visual Perception? 2 types of blindsight

Slide 4 Jorgensen- people with blindsight have a more constricted pupil Necessary conditions for the application of the term "seeing": (1) contrafactual condition - yes (2) condition of consciousness - no (3) epistemic condition - no Blindsight may, at best, be regarded as a type of unconscious and non-epistemic seeing, although some argue that this is incorrect. Therefore, blindsight is typically referred to as a phenomenal quality for seeing. 2 types: 1-awareness of stimulus 2-unawareness of stimulus

Rods characteristics

Slow Response - Long Integration Time High Amplification Saturation Response Not Directionally Selective Highly Convergent Retinal Pathways High Sensitivity Low Acuity Achromatic: One Type of Pigment

Neurotransmitters

Some almost always act at excitatory synapses, e.g., glutamine Some almost always act at inhibitory synapses, e.g., GABA (gamma aminobutyric acid) Most known neurotransmitters: Some can do either, e.g., acetylcholine, dopamine, seratonin, norepineperine (noradrenalin). Some have very brief actions, some have sustained actions. Some are inactivated by a membrane enzyme, some just break from the receptor and diffuse away. There are often mechanisms for uptake of the transmitter (or transmitter components) into the presynaptic membrane, repackaging them for use again.

Minor Dysfunctions are Associated with Sleep Insomniacs Have Trouble Falling Asleep or Staying Asleep

Some are much more common in children than adults: -Night terrors -Sleep enuresis (bed-wetting) *Both occur in SWS Somnambulism: sleepwalking -More common in childhood, but can persist into adulthood -Episodes last a few seconds to minutes, and the individual usually does not have any memory of it -Episodes occur during stage 3 SWS- therefore, more common in 1st ½ of the night when that stage predominates Insomniacs Have Trouble Falling Asleep or Staying Asleep: -15-30% of adults have insomnia -More commonly reported by older people, females, & drug users (i.e. tobacco, caffeine, alcohol) -A common outcome from various conditions Situational factors-- shift work, time zone changes, changes in daily routine These usually lead to transient sleep-onset insomnia (difficulty falling asleep) Sleep-maintenance insomnia- difficulty staying asleep -often due to drug use, neurological, and psychological factors -Sleep frequently interrupted by nighttime arousals -Especially evident in disorders of respiratory system

1-31 Mcgarry Physics of sound

Sound can propagate through a medium such as air, water and solids as longitudinal waves and also as a transverse wave in solids. Sound waves are generated by a sound source, such as the vibrating diaphragm or a stereo speaker. A drum produces sound via a vibrating membrane. Bats use echolocation to navigate and find food in the dark. Bats send out sound waves from their mouth or nose. When the sound waves hit an object they produce echoes. The echo bounces off the object and returns to the bats ears.

Greene: Physiology of the cochlea said not being tested

Sound enters the cochlea through the oval window Cilia of the hair cells, fibers reach up to gather info from the hair cells, bending of the cilia is what generates the changing of membrane potential Spiral ganglion. Both sensory input in hair cells and motor control of the hair cells Inner hair cells: sense of sound Outer hair cells: motor control, selective activation of some frequencies or amplify vibrations

Okino The Structure of the Ear Hearing Main subdivisions of the ear:

Sound vibrations are transduced (converted) into neural activity. Different parts of the ear have differing roles in hearing. Main subdivisions of the ear: Outer Ear Middle Ear Inner Ear

Sources of Pain

Sources of Pain - each source of pain reaches the CNS by a different pathway or combination of pathways. -Somatic pain: ???? -Visceral pain: pressure, tissue damage, chemical -Thalamic pain: stroke -Neuropathic pain: sharp and shooting -Psychosomatic pain: sensation, anxiety -Referred pain: sensation at a sight other than the other one -Phantom or illusory pain: have pain without any signals from the nociceptors

Males vs. Females

South American monkeys have only a single longer-wavelength pigment Genes for the M & L pigments are on the X chromosome Males have only 1 X chromosome mutations in the genes for the M & L pigments can impair color vision Females have 2 X chromosomes Defective photopigment gene on one X chromosome can be compensated for by the other

Summary

Standard 24-hour circadian rhythm regulates: sleep/ wake, hormone secretion & metabolism Large lesions on hypothalamus for rats will cause circadian rhythm inference *Sub-region of hypothalamus called suprachiasomatic nucleus is a biological clock regulator and located on the optic chiasm* *Collecting cells of the SCN in a petri dish shows they maintain electrical activity for several days if not weeks* Transplantation of SCN cells shows that the circadian rhythm can re-boot and adapt.

Patel Physiology of gonadal hormones What are gonadal hormones?

Steroid Hormones, manufactured by various glands by the enzymatic modification of cholesterol Major structural feature being four specifically arranged carbon rings Steroids vary by the functional groups attached to these four rings and the oxidation state of the rings Critical for triggering of reproductive behavior and gamete production Major Classes: Androgens Estrogens Progestin

MARTIN Brain structures related to sex drives Brain regions involved in regulating reproductive behavior Steroid Sensitive Brain Structures-VMH Periaqueductal Gray

Steroid Sensitive Brain Structures-VMH: Using steroid autoradiography, the hypothalamic nucleus contains many estrogen and progesterone- sensitive neurons. ○ The ventromedial hypothalamus (VMH) ■ Important for Lordosis ■ Estradiol can be injected here to induce receptivity in females ○ VMH also mediates the concentrations of hormones and ovulatory cycle Periaqueductal Gray: -Receives axons from the VMH -Projects to other neural connections and spinal cord -In the spinal cord: Sensory information from the mounting male will evoke the response of lordosis when the female's estrogen and progesterone levels are adequate

Gustav Fritsch & Julius Hitzig (late 1800s)

Stimulating dog brain activates opposite limbs. Animal research was pointing to localization of function. Removed skull of animal, stimulate cortex and get activation of opposite side muscles

Stimulus Movement Hierarchical organization

Stimulus Movement: -Some cells are only activated when there is movement of the stimulus -Also sensitive to direction of movement Hierarchical organization: -Simple cortical cells receive input from a row of LGN cells. only orientation of the stimulus -Complex cortical cells receive input from simple cortical cells, etc. Perceive just movement or movement in a certain direction -"Grandmother cells" theorized: cells that only react to a certain cell or group of cells to be activated. This cell would only activate when they see your grandma's face

Study assessing Eccentricity and Global Motion Processing

Study assessing direction discrimination using random-dot cinematograms at different retinal eccentricities (0, 8, 22, and 40) HROVAT SLIDE 9 Findings: -Performance varied as a function of retinal eccentricity for eccentricities greater than or equal to 22 degrees -Eccentricities up to 16 degrees showed consistent global motion discrimination -Increased eccentricity allows more noise Conclusion: a decline in motion sensitivity is a function of eccentricity because it allows more noise to take up space in the motion channel for perception

Study of the Endogenous Clock The Experiment and Findings

Study of the Endogenous Clock: -The rhythms have been studied using rodents' love for running wheels -Placed a hamster in a room which was continuously dimly lit -Showed continued daily rhythm in wheel running -Rhythm not exactly 24 hours. -Changed by a few minutes every day slowly keeping its own rhythm The Experiment and Findings: -A running wheel in a hamster's cage is monitored by a computer-linked device. Each revolution of the wheel is recorded by the computer that displays the activity pods -This hamsters activity record shows that it becomes active shortly before the start of the dark phase of the daily cycle and remains active during the dark period -When the timing of the light was shifted, so that the lights came on later and went off later each day, the hamster showed a phase shift of activity - In constant dim light, the hamster became active a few minutes later each day. This is free running activity rhythm indicates that the hamster has an endogenous clock that has a period slightly greater than 24 hours -Free-running- A rhythm of behavior shown by an animal deprived of external cues about time of day

Milk Let-down reflex

Suckling by the infant at the nipple is relayed by spinal nerves to the hypothalamus. The stimulation causes magnocellular neuro-secretory cells (PVN and SON) to fire action potentials in intermittent bursts. Bursts result in the secretion of pulses of oxytocin from the neuro-secretory nerve terminals of the pituitary gland. Oxytocin binds to cells in smooth muscle tissue in mammary glands, causing contraction, releasing milk. Positive feedback loop: -Conditioning to crying often occurs. -Crying babies can trigger lactation.

summation spatial summation temporal summation

Summation: The combining of excitatory and inhibitory influence upon the neuron. spatial summation: Spatial summation is when its coming in from different areas of the cell. When the input comes from two or more synapses temporal summation: when spikes that arrive at different times combine their influences. It is assumed that the spatial and temporal summation are important in the analysis of neural information, but beyond vague generalities, it is not clear how the process works.

Sleep deprivation in rats and complications from that Fatal familial insomnia

Sustained sleep deprivation in rats causes them to increase their metabolic rate, lose weight, and, within an average of 19 days, die. No single organ system seems affected in chronically sleep-deprived animals, but early in the deprivation they develop sores on their bodies. These sore mark the beginning of the end; blood tests revealed infections from a host of bacteria, which probably enter through the sores. These bacteria are not normally fatal, but because the rat's immune system is compromised because of sleep deprivation, they are unable to fight it. Fatal familial insomnia - an inherited disorder in which humans sleep normally at the beginning of their life but in midlife they stop sleeping and, 7-24 months later, die.

AIS symptoms and treatments

Symptoms: -Complete androgen insensitivity (CAIS): not obvious at birth, have female genitalia, the vagina and labia. They also have undescended testicles (not obvious), no period, no pubic or underarm hair etc. -Partial androgen insensitivity (PAIS): may have genitalia between male and female from birth. Small penis or an enlarged clitoris , partially undescended testicles. Hypospadias, where the pee hole located on the underside of the penis instead of the end. Treatments: -Hormone replacement therapy , for CAIS this includes estrogen replacement -For those with PAIS treatment includes estrogen replacement if the individual is more female and for patients who have a male gender identity may be treated with with testosterone and/or dihydrotestosterone (DHT) -Surgery

CAH symptoms and treatments

Symptoms: -Two groups of CAH include : Salt Wasting symptoms, dehydration, poor feeding , vomiting, low blood glucose etc., caused by too little aldosterone. -Salt wasting also involves low cortisol and high androgens, which cause female newborns to have ambiguous external genitalia, enlarged genitalia in males. -Simple virilizing (non-salt wasting) , too little cortisol, too much androgen, less severe aldosterone deficiency, symptoms include females with ambiguous genitalia and virilization. Virilization are characteristics of puberty of young children, even up to 2 to 3 years, like rapid growth , facial hair , pubic and armpit hair, deep voice, well developed muscles. Treatments: For classic CAH, treatment is started soon after birth , they are given steroids to replace the low hormones. -infants and children are given hydrocortisone -to replace cortisol adults can take hydrocortisone, prednisone, or dexamethasone -fludrocortisone, to replace aldosterone -eating salty foods or talking salt pill -surgery for ambiguous genitalia

Classifications of pain Johnson slide 5/6

Synonyms: Suffering, Agony, Torture, Torment, Discomfort Nociceptive: Neuropathic Mixed Category Pain (Other)

TESTOSTERONE SOLE CAUSE? FRATERNAL BIRTH ORDER EFFECT Why?

TESTOSTERONE SOLE CAUSE?: -Those same markers of fetal androgen do not provide for consensus about gay vs. straight men -Some markers suggest that gay men were exposed to less prenatal testosterone than were straight men FRATERNAL BIRTH ORDER EFFECT: -The more older brothers a boy has, the more likely he is to grow up gay (Blanchard et al 2006) -NOT: social influence of older brothers: Raising with older stepbrothers leads to no effect Biological brothers (same mother) lead to increase the probability of the boy's being gay EVEN IF raised apart (Bogaert 2006) Only right handed (not left handed) boys (Blanchard et all 2006, Bogaert, 2007) WHY? Immune system of a mother carrying son exposed for the first time to Y chromosome proteins may produce antibodies that affect development of subsequent sons (Blanchard, 2012)

Taste pathway to the brain Sha Slide 3

Taste projections extend from the tongue to several brainstem nuclei. The receptor cells on the tongue themselves aren't neurons as of yet, though they may be classified as such as we discover more about how we process taste; instead of action potentials they have graded responses. These responses are picked up by gustatory neurons, that trigger the release of NT, which are released to the brain stem nuclei in the cranial nerves associated with taste. The information travels to the thalamus via these nerves, and the thalamus then relays the sensory information to the gustatory cortex.

Temporal theory Temporal coding

Temporal coding is the frequency of the stimuli in the firing rate of the auditory neurons A specific frequency of sound (600 HZ) causes auditory neurons to fire 600 action potentials per second Temporal coding to identify the pitch of sounds is more apparent at lower frequencies (up to 4,000 Hz) A low frequency tone means low firing rates in the auditory nerve, and vice versa Pitch is not fully understood

Hormones Activational effect

Testosterone-drives males interest in intercourse-If castrated, males will stop ejaculating and mounting females Activational effect-temporary change in behavior resulting from the administration of a hormone

Special characteristic of smell

Thalamus: sensory info is relayed to the cortex, auditory, somatic, visceral, gustatory, and vision (BUT NOT SMELL) each have dedicated nuclei in thalamus Not just relaying information: thalamic nuclei have reciprocal connections with cortex. Regulates level of awareness- damaged can lead to coma

Dimensions of pain

The 6 dimensions of pain include -Physiological -Sensory -Affective -Cognitive -Behavioral -Sociocultural-Ethnocultural Slide 16

The Electromagnetic Spectrum Wavelengths and type of light: radio, infrared, visible, gamma ray

The Electromagnetic Spectrum: -Electromagnetic energy travels in waves -Electromagnetic spectrum is the range of all types of EM radiation -Radiation: energy that travels and spreads out as it goes Wavelengths and type of light Radio: emitted by stars and gasses is space Infrared: light emitted by our skin and objects with heat Visible: light that our eyes can detect Gamma Ray: highest energy, shortest wavelength, used by doctors

The Power of Training

The Power of Training: TRAINING - can change motor representations in M1 M1 is W I D E R in piano players (especially the hand region) The YOUNGER the musician was at the start of musical training, the LARGER the gyrus in adulthood SLIDE 8 PICTURE Haueiesen and Knosche (2014) compared the motor activation in pianists and nonpianists while listening to piano pieces -Pianists were found to have a statistically significant increase of activity above the region of the contralateral motor cortex -Hence, when listening to well-trained piano music, pianists exhibit involuntary motor activity involving the contralateral primary motor cortex (M1)

The Visual Fields of the Eye The crossing over

The Visual Fields of the Eye: When someone looks at the back wall of a room, the entire scene, top to bottom, is divided down the middle For the right eye, the right half of the visual field goes to the nasal hemiretina while the left goes to the temporal hemiretina. It is vice versa for the left eye, so the right half of the visual field goes to the temporal hemiretina, while the left goes to the nasal hemiretina. The Crossing Over: -The optic nerve fibers from the nasal hemiretina cross over the optic chiasm but the optic nerve fibers from the temporal hemiretina do not cross over. -The fibers are called the ipsilateral and contralateral fibers -Afterwards, each half of the visual field is delivered to the lateral geniculate nucleus and cortex on the opposite side of the brain. JOHNSON SLIDE 14

action potential depolarization hyperpolerization C18

The action potential -- aka spike -- is produced by a large increase in Na+ permeability followed by a smaller increase in K+ permeability. The rising phase is called depolarization, and the afterpotential (below the resting potential) is called hyperpolerization.

Descending Pain Pathways Neuropathic Pain

The brain is a center that interprets signals and makes constant adjustments accordingly, leading to a descending pain pathway Involves brain structures such as dorsolateral prefrontal cortex, which communicates with anterior cingulate cortex These pathways have an inhibitory effect, that can stop the centers that relay pain signals up the ascending nociceptive pathways Neuropathic Pain: Pain that persists long after the injury has healed -Hsieh et al (1995) observed consistent activation of the cingulate cortex in patients with chronic pain -Phantom limb pain is a type of neuropathic pain, and treatment of it is demonstrated in this photo

The cerebellum slide 4 Damage to the cerebellum? Progressive Supranuclear Palsy:

The cerebellum: -Don't really know how it works -Medial hemispheres are involved in adjusting limb movements -Vermis involved in posture equilibrium and eye movement -Motor Learning: lateral sides -Later hemispheres are involved in planning and programing motor movements. Skillful movements such as learning how to play an instrument or a sport Damage to the cerebellum? : -Depends on the part of the cerebellum that was damaged -Lesion to any midline structure will cause problems with balance -Lesions to lateral structures causes difficulty in movement of the extremities Progressive Supranuclear Palsy: -Damage to nerve cells affects movement, control of walking (gait) and balance, speech, swallowing, vision, mood and behavior, and thinking -Cerebellum probably plays a role in coordinating context with proper emotional expression -Currently have no treatment

Color Perception

The cone receptors differ in absorption amounts due to the amount of opsin amino acids in the receptor Balance of activity between short, medium, and long wavelength cones determine how we perceive color Additive mixing: lights of different wavelengths Note: magenta can only exist as a metamer. There is no monochromatic wavelength for it and it is in the "non-spectral purples" region in the color wheel Color perception is produced by combinations of these 3 types of cones: -Each color produces a unique set of responses from the S, M, and L cones, and is therefore interpreted correctly by the brain.

The human brain flavor systems that evaluate and regulate food intake

The diagram shows the areas involved in the perceptual, emotional, memory-related, motivational and linguistic aspects of food evaluation mediated by flavour inputs slide 10 lai

Large axons and spikes

The electrical spread is greater with large axons, for there is more volume (and thus more ions) that can carry the electrotonic influence. Therefore the spike travels faster in larger axons.

Scotopic optical system

The scotopic optical system is also known as the rod-based system. Similar to how rods function optimally in low light, so does the scotopic optical system. Drawback: It is insensitive to color.

Cranial nerves

brain stem (madulla oblongata) Connecting fibers carrying info from one side of cerebellum to other Optic nerve: eyeball carry info Various nerves, some are motor some are sensory

Understanding central deafness Pure word deafness: Auditory agnosia: Cortical deafness Auditory hallucinations:

The experience of central deafness varies. Some types are: Pure word deafness: Easily confused with wernicke's aphasia. Usually result of damage between Heschl's transverse gyrus and medial geniculate or corpus callosum fibers between contralateral superior temporal Auditory agnosia: Characterized by inability to identify non-verbal sounds. Usually result of right hemisphere lesion to anterior "what" stream. Cortical deafness: combination of pure word deafness & auditory agnosia Auditory hallucinations: the illusory experience of a complex sound like music or voices. Usually result of injury to superior temporal auditory association areas.

Understanding conduction deafness Siebert slide 4 pic/words

The experience of conduction deafness essentially 'turns the volume down' on incoming auditory stimuli - this may diminish a person's ability to hear very quiet sounds Conduction deafness has many causes - luckily this kind of deafness can usually be ameliorated by medical treatment or surgery.

Understanding sensorineural deafness

The experience of sensorineural deafness, like conduction deafness, "turns the volume down on sound" - this may make auditory stimuli like speech seem muffled or unclear. Because this form of deafness arises out of physical damage to the hair cells (cilia), it cannot be corrected by medical treatment or surgery - this makes sensorineural deafness irreversible.

Flow/permeability of ions C24

The flow of ions at one site provides electrotonic influence on neighboring parts of the neuron (and on any electrodes that are present). Electricity has a push pull nature of it This influence gets weaker with distance from the point of ion flow. Some of the membrane in neurons and muscles has Na+ channels that are sensitive to this electrotonic influence. Thus an increase in permeability at one spot can spread to neighboring portions of the cell. Axons have these electrically excitable Na+ channels, so the depolarization can travel from one end to the other. The permeability increase at a given location lasts only about a millisecond, thus the excitation spreads like a burning fuse. Because the depolarization is moving, the later component of the spike, wherein potassium permeability increases, is seen as a trailing edge. After the membrane potential returns to normal, the axon is ready to transmit another spike.

How Does it Work? 3 canals Ampulla

The semicircular canals are composed of 3 canals that are oriented in different planes in which the head rotates. Connected to the saccule and utricle -Roll (Rotation around x-axis) -Pitch (Rotation around y-axis) -Yaw (Rotation around z-axis Ampulla: an enlarged region at the base of the canals, containing receptor cells (hair cells) of the vestibular system.

Feedback system Overview

The hypothalamus and anterior pituitary both receive synaptic inputs from many other brain regions. These inputs are either excitatory or inhibitory. They also receive a feedback loop from the hormone of the endocrine gland that is being stimulated and releasing hormones. This is to let the brain know that the signal worked and no more hormones are need to stimulate the wanted response. PATEL SLIDE 10 Overview: This system has a high level control over the endocrine organs in the body and translate brain activity into hormonal action. If someone were to lose their connection between the pituitary gland and the hypothalamus they would have major hormonal disruptions as well as atrophy of the pituitary gland.

Inner Ear

The inner ear is comprised of the cochlea and the vestibular apparatus. The cochlea, the fluid-filled coil, converts vibrations from sound into neural activity. There are 3 parallel canals that make up the cochlea: -Scala vestibuli -Scala media -Scala tympani When sound vibrations push the ossicles of the middle ear into the oval window joining the middle ear to the inner ear, the noncompressible fluid inside the cochlea must have a second membrane-covered window that can bulge outwards as an outlet. This second window is known as the round window and separates the scala tympani from the middle ear. The organ of Corti lies within the scala media and is the basis of the conversion of sound into neural activity. It is comprised of sensory cells, supporting cells, and the ends of nerve fibers for auditory input. Slide 7

The Organ of Corti

The sensory cells in the organ are called hair cells, whose stereocilia transduce the vibrations from the cochlear fluids into neural activity. The basilar membrane is the base of the organ of Corti, which ripples along with the fluids of the scala vestibuli. The basilar membrane is tapered and is at its narrowest and most stiff near the base of the cochlea. Tectorial membrane: A gelatinous membrane that contacts the sensory hair cells. Hair cell stereocilia are able to be influenced by the movements of the basilar membrane because the tectorial membrane does not move. slide 8

The Limbic System

The olfactory bulb is one of the structures of the limbic system. The information captured by the sense of smell goes from the olfactory bulb to other structures of the limbic system. Memory/emotion can be connected with smells The circular nature of the interconnections: slide 9 Lai

Olfactory Processing olfactory bulb, glomerulus, olfactory receptors

The olfactory bulb receives axons from olfactory receptor neurons , from there it forms synapses with dendrites of mitral cells and that terminates onto a specific glomerulus. A glomerulus is a spherical structure that gets information from one specific class of odorant receptors. The olfactory receptors will respond to only one odorant which are scattered throughout the epithelium The connections of these receptors that respond to a given odorant will collect and stimulate a single glomerulus and a single mitral cell which sends this information to the brain. cabral slide 7

Optic Tract

The optic tract is part of the visual system in the brain. A continuation of the optic nerve that relays information from the optic chiasm to the lateral geniculate nucleus (LGN), pretectal nuclei, and superior colliculus. Composed of the left optic tract and the right optic tract, each of which conveys visual information exclusive to its respective contralateral half of the visual field. JOHNSON SLIDE 7

Mach bands Perception of Light

The phenomenon, Mach Bands, suggests that perceived brightness next to transitions is affected by the brightness of adjacent zones. Perception of Light: Our visual experience is not a simple reporting of the physical properties of light It is our perception of light versus dark created by the brain, in response to many factors. These last examples are a version of "simultaneous contract" An effect that Gestalt Psychology used to challenge earlier work of psychophysics, which assumed the perception would be controlled by the amount of light falling at a given location

Primary Visual Cortex (V1)

The primary visual cortex is located in and around the calcarine fissure in the occipital lobe. The left and right hemispheres of the brain receive information directly from its ipsilateral lateral geniculate nucleus that receives signals from the contralateral visual hemifield. The visual cortex in the right hemisphere receives signals from the left visual field and the left hemisphere receives signals from the right visual field.

The problem with Sleeping Drugs Best Treatment for Insomnia

The problem with Sleeping Drugs: -None provide completely normal night of sleep in terms of how much time is spent in each of the sleep states -Diminished effectiveness over time oftentimes leads to increased self-prescribed dosages -Causes changes in pattern of sleep while drug is in use and the following days -Sleep drunkenness & drowsiness -> impairs waking activity or creates memory gaps of daily activity Best Treatment for Insomnia: -Develop regular routine to exploit body's circadian clock -Use an alarm clock to wake up faithfully at the same time each day, then go to bed when sleepy -Avoid daytime naps and caffeine at night -Have a bedtime routine- dark, quiet environment can help sleep onset -Avoid using smart phones or laptops before bedtime

Light Control

The pupil and Iris are the first method used to control light intensity Dilation- opening of the pupil in low light settings. Controlled by the sympathetic system of the autonomic system Constriction-closing of the pupil in bright settings. Controlled by the parasympathetic system The pupil only controls light to a 16-fold range compared to the billion-fold range of light sensitivity the eye has

Classification of Sensory Systems-Chemical system

The receptors are located in the nose and on the tongue Used a but in lungs for carbon dioxide/oxygen levels Helps detect danger and hazards in the environment In charge of taste and smell Receptors are called chemoreceptors

Oxytocin and ASD

The role of oxytocin in the medial prefrontal area is thought to be quite significant in social communication. Irregular function in mPFC regions is thought to contribute to some of the antisocial behaviors attributed to ASD One study found that there was a close connection between oxytocin levels and the mPFC in ASD patients. (Watanabe et al., 2013) They also found that intranasal administration of oxytocin ameliorated some symptoms of ASD And, that the duration of the supplementary oxytocin corresponded to temporarily recovered activity in mPFC.

Changing Findings And Definitions

The role that the occipital lobes, and specifically the primary visual cortex, play for vision has been debated for over a century. Blindsight is a controversial topic because of the changing criteria based on findings that challenge the original definition. A difficult feature of blindsight is that the experimental evidence fails to converge on a single pathway, but more recent research has confirmed that blindsight follows from V1 lesions via a colliculogeniculate pathway.

The sequence of sexual differentiation Genetic diseases

The sequence of sexual differentiation: 1. the presence of a y chromosome will direct indifferent gonads to develop as testes. Genetic sex XY, gonadal sex testes, hormone testosterone, phenotypic sex penis, scrotum, etc. Hormones from the fetal testes masculinize the body and the brain (at least in nonhuman mammals) 2. without a y chromosome the indifferent gonads develop as ovaries. Genetic sex xx, gonadal sex ovaries, hormone no testosterone, phenotypic sex clitoris, labia, etc. The fetal ovaries do not secrete androgens, so the body develops in a feminine fashion as does the brain Genetic diseases: Recessive sex-linked traits, such as hemophilia and red-green colour blindness, occur far more frequently in men than in women. This is because the male who inherits the recessive allele on his X chromosome has no allele on his Y chromosome to counteract its effects. The female, on the other hand, must inherit the recessive allele on both of her X chromosomes in order to fully display the trait.

The spinal cord in mammals

The spinal cord in mammals: -In rats, the bulbocavernosus (BC) muscles that surround the base of the penis are innervated by motoneurons in the spinal nucleus of the bulbocavernosus (SNB) -On the day before birth, female rats have BC muscles attached to the base of the clitoris that are nearly as large as the BC muscles of males and that are innervated by motoneurons in the SNB region. In the days before and after birth, many SNB cells die and the BC muscles of females die -Androgens act on the BC muscles to prevent their demise, and this sparing of the muscles causes the innervating SNB motoneurons to survive

Brain structures used in sound localization Binaural hearing

The superior olivary complex - contains the lateral superior olive (LSO) and the medial superior olive (MSO), the two cell groups that process the main cues for sound localization The inferior colliculus- integrates information about intensity differences and latency differences. Binaural hearing: -Binaural-having or relating to two ears -Binaural hearing- the ability to integrate information that the brain receives from the two ears -This hearing lets us listen in noisy, complex environments, while also helping us localize sounds

2-2 Martin Temporal coding of pitch Theories for pitch perception

There are 2 principal theories of how the auditory system codes the pitch of a sound: ● Place theory ● Temporal theory (timing) -Telephone (Rutherford) -Volley (Wever and Bray) The waveform of a sound with a strong pitch is periodic The basis of temporal theory for pitch perception is the rate of neural firing that occur in reaction to the vibrations on the basilar memory

Different types of receptors

There are two main types of receptors that are found for receptive stimuli: Phasic receptors: strong display of adaptation; once a stimulus occurs, the receptor will show a quick adaptation (shutting off) Tonic receptors: Shows little to no adaptation at all throughout the whole stimulus duration. These are usually pain receptors Both transmit information about a stimulus, but for different durations. Tonic is always much longer.

Summary

There are two primary modes of human vision are: Photopic (well-lit conditions necessary and involve color perception/cone system) and scotopic (Rod-based monochromatic vision in dimly-lit conditions). Some parts of the eye structure: lens, cornea, iris, retina Cones respond to specific wavelengths of light while Rods respond to all wavelengths of light Scotopic optical system is known as the rod-based system

Olfactory Receptors

These olfactory receptor cells which are bipolar neurons have cell bodies that lie within the olfactory mucosa. The olfactory neurons can die and be replaced in adulthood , this is where basal cells come in and can differentiate into new neurons. Production is strong for the olfactory receptors cells and the life of these cells are long as well. The supporting cells work to destroy any damaging odorant molecules so the olfactory receptor cells avoid damage. Olfactory receptor cells have cilia which penetrate the layer of the mucus , the mucus is where odorants must dissolve so that receptor molecules on the cilia can be stimulated.

Trichromatic Color Principle Thomas Young Herman Van Helmholtz

Thomas Young: -Thomas Young stated that color vision results from the presence of three different receptors -Suggested that the eye contained photoreceptor cells sensitive to varying wavelengths of light in the visible spectrum. -Blue sensitive, yellow sensitive, and green sensitive receptors tuned to its part of spectrum -Stated that receptors take separate path to brain & color of object is recognized depending on what color receptor is activated Herman Van Helmholtz: -Helmholtz suggested that there are three distinct cone receptors with different peak sensitivities: short wavelength (blue), medium wavelength (green), and long wavelength (red) receptors -Proposed that strength of the signals detected by the receptor cells determined how the brain interpreted color in the environment

Recap

Three ascending pain pathways: archispinothalamic pathway, paleospinothalamic pathway, and the spinothalamic system. Certain areas in the brain are important in processing pain: medulla oblongata, thalamus, cortical areas, neurotransmitters, cingulate cortex. Also there are descending pain pathways, that to a degree, have an inhibitory effect on pain Neuropathic pain: pain that persists long after an injury has healed

Kachmer The Electromagnetic Spectrum and Dimensions of Color Perception Three Stages of Color Perception Color is Created by the Visual System hues, vibrations

Three stages: 1. Cones receive visual information 2. Information processed by neurons in local circuits of the retina 3. Information is processed in primary visual cortex and other visual cortical areas Color is Created by the Visual System: Several distinguishable hues Hues appear different because of every light particle (photon) vibrates at a different frequency as it travels across space, behaving like a sinusoidal wave Vibrations of photons vary in frequency, and thus wavelength, and we can detect these differences: -Faster vibrations and shorter wavelengths = blue/green -Slower vibrations and longer wavelengths = orange and red

Each taste cell detects just one of the five basic tastes

Thus, the encoding of taste perception could be very straightforward, and the brain would simply monitor which specific axons are active in order to determine which tastes are present "Labeled-line system" In this system, there would be no need to analyze complex patterns of activity across multiple kinds of taste receptors The process in which we would need to analyze these patterns of activity is known as "pattern coding."

The Endocrine System: endocrine glands, hormonal secretions and levels

Today we know there are a lot more than four humors. There are hormones that excrete within the body and are called endocrine glands from the Greek endon "within" and krinein "to secrete" vs. the exocrine glands (tear glands, salivary glands, sweat glands), which use ducts to secrete fluid outside the body. Ancient civilizations understood the importance of hormones. Aristotle was able to describe the effects of castration (removal of the testes) in roosters and compared them with the effects in eunuchs (castrated men). The endocrine system provides regulation of the body through hormonal secretions. These are carried through the bloodstream to other parts of the body, where they act on specific target tissues to produce physiological effects. Changes in hormone levels can produce striking changes in brain function: cognitive abilities, emotions, our appetite for food, drink or sex, our aggressiveness or submissiveness, how we care for our children etc.

Topographic mapping Sensitivity and acuity Animunculus?

Topographic mapping: Note the regions of the body project to specific regions of the brain. Sensitivity and acuity: Need greater acuity/sensitivity for survival to manipulate things. Note also the mismatch of relative size. The amount of cortex relates to. Animunculus?: Similar maps have been found in animal brain. S1 primary somatosensory cortex, have greatest body map. The neurons in each area respond to the body zone that is illustrated.

Electrical stimulation ASK FOR SLIDES

Transcutaneous electrical nerve stimulation (TENS): Mild electrical stimulation applied to the nerves in the area around the injury May close the "gates" in spinal cord Releases endogenous opioids Activates low-threshold, myelinated nerve fibers, results in inhibition of small

Sensorineural deafness

Transduction of sound Where: the inner ear- cochlea with hair cells What: "when damages to the cochlear apparatus interfere with the ear's ability to transduce sound waves into electrical neural impulses" Why: -genetics, aging, head trauma, exposure to loud noise, illness (such as menengitis) -ototoxic drugs - medications that can damage the ear, thereby causing hearing loss or a ringing sensation (tinnitus). Ex. Includes aspirin, gentamicin, ibuprofen, among others

Kumar Trichromatic Color Principle and Hering's Opponent Theory Color Vision Principles

Trichromatic color principle and the opponent process theory are competing principles Trichromatic color principle explains color vision at the receptor level The opponent process theory explains color vision on a neural level (how photoreceptors are interconnected)

Turners Syndrome Symptoms Treatments

Turners Syndrome: -Embryo contains only one sex chromosome, a single X, embryos cannot survive with just a Y chromosome. -Turners Syndrome results in recognizable ovaries that are underdeveloped, since no SRY gene is available. -A person with this condition will develop into a female unless the indifferent gonad becomes a testis and releases hormones. Symptoms: -Webbing of the neck -Broad chest -Low set ears -Low Hair Line -Short stature and delayed growth -Cardiovascular problems Treatments: There is no cure but treatments do exist that can help with the symptoms. -growth hormones and others, can help imporve growth especially in adulthood. -estrogen replacement , given around the age of 12 or 13 to help with development of secondary sexual characteristics such as breast and menstruation. For menstruation a combination of estrogen and progesterone to help with the monthly period and keep the womb healthy. - also cardiac surgery if the heart is defected structurally

Rene Descartes early 1600s

Turning point in thinking: Descartes suggested hydraulic mechanisms for mediating some behaviors. How the fluids might carry pressure would animate muscles Thought of this when young visiting palace and saw fountain statue that bent to him when he stepped on a certain stone, uses a water valve system, so why not the body too Process often viewed as requiring pressure from flow of fluids...but sometimes with mechanical components. Fluid pressure activating eyeball to make it rotate. Optic nerve has rods to fluid in ventricles that would create an image. Pinneal gland thought of as seed of soul

Two models The preoptic area of rats Difference in the sdn-poa between males and females

Two models : 1) The Preoptic Area of Rats 2) The Spinal Cord in Mammals The preoptic area of rats: -Roger Forski examined the preoptic area (POA) of the hypothalamus in rats -Investigators found a nucleus within the POA that has a much larger volume in males than in females This nucleus was named the sexually dimorphic nucleus of the POA (SDN-POA) -Evidence that testicular androgens somehow alter the development of the SDN-POA Difference in the sdn-poa between males and females: The sexually dimorphic nucleus of the pre optic area (SDN-POA) is much larger in male rats than in females

Medial Geniculate nucleus

Two nuclei on either side which act as the relay in the thalamus for the auditory cortex Information comes here from the inferior colliculus before it goes on to several auditory cortical areas It has three major divisions: -Ventral sub nucleus: Subdivision specific to auditory processing ; important in relaying input regarding frequency, intensity, and binaural information to the auditory cortex -Dorsal sub nucleus: Broadly tuned responses, as well as multimodal responses to somatosensory as well as auditory stimuli -Medial sub nucleus: Involved in detection of the relative intensity, and duration of sound

Nociceptor Molecules Congenital Pure Analgesia

Two receptors sensitive to pain: TRPA1 and TRPV1 Both ion channels that are directly gated by the stimulus and carry an influx of calcium and sodium Congenital Pure Analgesia: -Incredibly Rare: only 80 cases documented, 300 reported worldwide -Often die young (by age 25) because they can't tell when they're doing something harmful to themselves. They usually don't die from injuries, they can't sweat and control body temp, so when they get a fever they usually die from that -Prevents inflammation and sensitization of injuries, which leads to continued injury -Knowledge of the condition can allow for successful management and treatment plan

Myelin

Vertebrates have developed another method of gaining speed, which is to wrap the axon with myelin. This forces the electrotonic current farther down the axon, for it can pass out from the interior only where the resistance is low -- this being at the nodes of Ranvier.

Vertigo and dizziness Vision Disturbance

Vertigo and dizziness: Cause: often by loose calcium particles in semicircular canals Spinning or whirling sensation - feels like the world is spinning Symptoms can be present even without movement Lightheaded Vision Disturbance: The vestibular system sends motor control signals via the nervous system to the muscles of the eyes with an automatic function called the vestibulo- ocular reflex (VOR). VOR: crucial part of maintaining balance and clear vision, controlling eye positions so that when the head moves, gaze remains stable. Words on a page may appear doubled Sensitivity to light, computer monitors and televisions

Vestibular Rehabilitation Therapy (VRT) Medications

Vestibular Rehabilitation Therapy (VRT): Effective in improving symptoms related to many vestibular disorders An exercise based program designed to reduce vertigo, dizziness, gaze instability and imbalance. Teaches the brain to use other senses to substitute for the deficient vestibular. Medications: "Double-Edged Sword" - it provides benefits in managing the disease, but has side effects like dizziness and muscle fatigue (which is part of the problem they're trying to solve) Because they suppress brain function, they should not be used for long periods of time. Ex: meclizine, dimenhydinate, etc.

Yehezkilof The Vestibular System What is the Vestibular System? Semicircular canals

Vestibular System: The apparatus of the Inner ear involved in balance and hearing. -Crucial for planning body movements, maintaining balance, directing sensory organs (eyes & ears) -Cochlea: Hearing -Labyrinth: balance Semicircular Canals: 3 fluid-filled channels inside the inner ear that provides us with continuous awareness of motion. Ye slide 2 pic

Visible Light

Visible Light: Human visual system only responds to frequencies within a very narrow range of the EM spectrum 400-700 nanometer wavelengths Particles outside of this wavelength are no longer called photons Color of an object depends on which wavelengths of light are reflected and which are absorbed

Summary****

Visual acuity is the sharpness of vision Eccentricity is an angular measurement of how far something in the visual field is from the fovea We experience a blind spot because of the optic disk at the optic nerve Low-contrast letters require a low eccentricity (less than 2 degrees) than high-contrast words

What about the higher frequencies? Nervous system and sound frequency

Von Bekesy called his idea Travelling Wave Theory. The sound wave travelled down the basilar membrane until it reaches the optimum part of the membrane and the vibrations are greatest at the corresponding part. That would be where the biggest vibrations were. Nervous system and sound frequency: -Thought the nervous system provided response to the frequency of the sound through lateral inhibition -This means that the neuron at the maximum vibration would be activated and the neighbors would be suppressed.

Results

Von Bekesy came to the conclusion that the area on the basilar membrane that showed the largest vibration in response to the sound were based on the frequency of the sound. Higher Frequencies displaced the basilar membrane at the base of the cochlea. Lower Frequencies displaced at the apex of the cochlea This differential lead to Von Bekesy's Theory being known as place coding due to the place on the basilar membrane corresponding to the frequency of the sound.

Patel: Von Bekesy Theory of Sound Encoding

Von Bekesy came up with a "new method" for explaining how we encoded pitch which he won a Nobel Prize for in 1961 Built upon the basic principle that Helmholtz proposed almost 50 years before, but wanted to try and distinguish himself from Helmholtz. Came up with these after learning of the responses of the basilar membrane to sound. Hypothesized that sound waves caused the membrane to ripple. Used two different methods to test his theory.

Wavelength

Wavelength the distance between successive crests McGarry slide 2

Electrotonic Influences

We have been describing the electrical influence from flow of positive ions through the membrane. The term "electrotonic" serves as a reminder that the electrical influences are being conducted by ions in a water medium -- and not by free electrons as would be the case in a metal wire.

Measuring effects of permeability C10-12

We'd like to measure the electrical effects of this permeability, but can't do so if both electrodes are outside the cell. But we can see the resting membrane potential if we can get an electrode inside!!! Stick tip in to create this. The potassium flows out now down their concentration gradient This happens because: silver makes a good electrode, which produces silver chloride molecule that drags electrode from silver to chloride and free silver. And the other way Cl- attaches to electrode to make AgCl and the negative electrode is the source of electricity

Shamamyan Sexual Predation: Can it be Treated? What does "sexual predator" mean? Rates of Recidivism Treatment Options

What does "sexual predator" mean?: -A sex offender who has been convicted of a sexually violent offence and who suffers from a mental abnormality or personality disorder that makes him or her likely to engage in predatory sexually violent offences. Rates of Recidivism: -Perceived: 70-80% -Actual: 10-20% -In a recent study about psychological treatment: Untreated offenders: 17.3% Treated offenders: 9.9% -Psychological intervention aims to increase the efficacy of treatment for offenders, and stress behavior modifications by recognizing and avoiding their criminal impulses. Treatment Options: -Hormonal Therapy - reducing testosterone and sexual drive -Treatments for mood disorders, anxiety disorders, ADHD, neurological disorders, etc. - occur more frequently in sexually impulsive men, particularly sex offenders.

Zhong Sexual dimorphism of the brain What is sexual dimorphism?

What is sexual dimorphism?: -Organizational hypothesis: difference in male and female rats behavior results primarily from androgenic masculinization of the developing brain -Sexual Dimorphism: The condition in which males and females of the same species showed pronounced sex differences in appearance -In all species studied so far, androgens are responsible for the sexual dimorphism seen in the brain Examples: pheasants, african lions, Orange tip butterflies

Hrovat: Visual Acuity as a Function of Eccentricity What is visual acuity? What is eccentricity?

What is visual acuity?: Sharpness of vision measured by the ability to discern letters (or numbers) at a given distance according to a fixed standard Normal: 20/20 vision What is eccentricity?: Refers to the angular distance from the center of the visual field, the fovea Essentially, how far away a point in the visual field is from the fovea- we measure this in degrees

What we know so far... Hormonal Therapy

What we know so far... -Significant results are modest, at best. There are no great changes found as of yet as a result of treatment for sexual predation -It seems to be beneficial only for those who are high-risk repeating offenders, while some studies have shown that those at low risk may even increase their risk of reoffending after treatment -Older offenders have no benefits from treatment. Hormonal therapy: -Testosterone is linked to sexual arousal, thus a decrease in testosterone should lower sex drive -Hormonal agents that reduce testosterone levels are known as antiandrogens - break down and eliminate testosterone, as well as inhibit the production of LH in the pituitary, resulting in inhibition of the production of testosterone -By reducing sex drive, it is hoped that it will also reduce the impulse of sexual offenses in those who are at high risk for reoffending.

2-21 Cabral Anomalous Gender Differentiation in Humans When Sexual Differentiation Goes Wrong (4 things)

When Sexual Differentiation Goes Wrong: -Sometimes sex differentiation goes wrong and this causes a person to not develop fully into a female or male. 1)Turners Syndrome 2) Congenital adrenal hyperplasia (CAH) 3) Androgen insensitivity syndrome (AIS) 4) Guevedoces

Opening of sodium pores C16 Hyperpolarization:

When a neuron is stimulated, the increase in Na+ permeability produces depolarization. If the threshold is exceeded, all the sodium pores open to generate an "all or none" action potential. Hyperpolarization: when you go below resting, potassium channels will open after the sodium channels opened. Following a spike, or from other influences on the neuron, additional potassium channels can open. This results in the inside of the cell becoming more negative than it is at rest...

The Camera (Structure of the eye) bhada slide 4 Optics of the Eye

When light enters the eye it becomes inverted and switches left to right and the crossing in the brain is how it becomes correct in the image you see Cornea -First structure light enters through -Replaces the Sclera-tough white sheath that makes up rest of the eye -Refracts light entering eye Iris -Colored part of eye -Diaphragm that changes size of the pupil Pupil -Hole at the center of Iris -Aperture through which light enters the eye

Phase locking

Where nerve fibers sensitive to a particular frequency range fire at the same phase of every cycle of a sound in that range

Mixed deafness

Where: middle ear - conductive aspect cochlea/cochlear nerve - transductive aspect What: "a combination of both conductive and sensorineural hearing loss" Why: -Disorders that damage the middle ear* -Disorders that affect the cochlea or cochlear nerve* *shown in previous slides*

Central deafness

Where: auditory cortex + associated areas What: "when cortical areas utilized to process & interpret sound information are damaged leading to specific deficits in complex sound processing - very rare" Also known as "cortical deafness" Why: Lesions, stroke, tumors

Conduction deafness- Where what and why

Where: the middle ear- What: "when the architectural elements of the ossicles - the malleus, incus & stapes - become unable to concentrate the vibrations of the sound wave onto the oval window". the ossicles pass along the sound and it conducts, but if the mechanics of this are disrupted it can be diminished Why: ear infection, allergies, benign tumors, fluid in the middle ear (from colds)

Itching & Pain

Why do we itch? Itching and pain are very common - they share a pathway in the spinal cord, the spinothalamic tract. Recent studies show that where pain and itching intersect, there is a chemical messenger: serotonin. In the brain, serotonin plays roles in mood, circadian rhythms and hallucinations. More than a dozen receptors for serotonin In the gut, it helps to control whether or not you end up with diarrhea, for example. In the skin, however, serotonin can help to inhibit pain and exacerbate itching. Pruriceptors: receptors for itch

Androgen Insensitivity Syndrome (AIS) Two types

XY zygote inherits a dysfunctional gene for the androgen receptor, so androgenic hormones will have no effect on the tissue of interest. This faulty does not let the male body respond to testosterone properly. Gonads develop normally into testes, testes produce AMH (inhibits mullerian ducts structures), and they produce testosterone, problem is with receptor proteins. Since the androgen receptors are faulty , the wolffian ducts do not develop and instead the external genital tissue forms a clitoris and labia. For women, at puberty they develop breast but do not menstruate since ovaries and uterus are absent. AIS women are infertile as well. Two types: Complete androgen insensitivity syndrome (CAIS): genitals are entirely female since testosterone does not exert its effects on sexual development. Partial androgen insensitivity syndrome (PAIS): genitals are between male and female since testosterone has some effect on the sexual development.

2-16 Satterfield Hormone Influence and Control of Sex Drive in Animals Zygotes How They Work Together Sexual Behavior of Rats

Zygotes: -Gamete- a sex cell (sperm or ovum); contains only unpaired chromosomes and has half of the usual number of chromosomes -Sperm-gamete produced by males to fertilize eggs (ova) -Ovum-an egg; the gamete of females -Zygote- fertilized egg How They Work Together: -In mammals, birds and reptiles: -Internal fertilization: the fusion of gametes (sperm and ovum) within the female body to form a zygote Sexual Behavior of Rats: -Rats do not bother with lengthy courtship -Rats do not stay with the same partner after copulation -Odors play a huge role in attraction

Somatosensory Pathway

action potential to spinal column, axon something, then to medulla, then across to terminate in the thalamus. Contralateral. Thalamus send Slide 4-5 1. Touch Receptors detect and send action potentials to dorsal spinal cord. 2. The axon joins the dorsal column of white matter and ascends to the brain 3. The axon makes it first synapse, innervating a medullary neuron. It sends its axon across to terminate in the thalamus. 4. The left thalamus receives information about the right side of the body. The thalamus sends this information to the somatosensory cortex on the same side.

2 Functional Specialization of the Brain

diagram of stains. B slide 2 Nissl stain: textile stain with neurons, certain classifications of brain areas were done with Braudman's numbers over the cortex, parametal cells? Golgi stain: silver, neurons staines, shows everything such as branches/dendrites, cell body, axon, and axon terminals Slide B3: This diagram provides a good sense of the scale of neuron components that we will be discussing.

Sex ed sigmund freud

early 19oo's: sigmund freud mid 19oo's: alfred kinsey mid-late 19oo's: virginia johnson, william masters contemporary: too many to list! sigmund freud: -A neurologist turned psychoanalyst of the victorian age -what he did: treated pathology by transducing un/subconscious "sexual" experience into conscious dialogue between analyst and patient. -how he redefined sex: shifted victorian culture by taking sex out of the private mind and into public discourse.

Biological electricity

ionization concentration gradients semipermeability resting membrane potential action potentials

ionization concentration gradients

ionization: When one of these salts is poured into water, it dissolves, and ionizes: they dissassociate from each other and separate into their compounds. Each atom carries a little bit of charge: K+ (missing electron) CL- (extra electron) Key players: NaCl (table salt) KCl (salt substitute) Here is a mixture of sodium chloride and potassium chloride, wherein the molecules have ionized. All the sodium and potassium atoms carry a slight positive charge, and all the chloride atoms carry a slight negative charge. concentration gradients: The ions migrate from regions of high concentration into regions of low concentration. In other words, the ions move down their concentration gradient

original conceptual model of human sexuality It's not always about (biological) sex. study hormones

original conceptual model of human sexuality: 1. excitement (receives input) 2. plateau (passes threshold) 3. orgasm (rapid 'rush') 4. resolution (returns to resting) It's not always about (biological) sex: Crews & Fitzgerald (1980) what: Studied endocrinology of parthenogenesis in female whiptail lizards during various stages of the ovarian cycle how this re-defined sex research: by correlating fluctuations in estradiol and progesterone to 'feminine' & 'masculine' typical sexual behavior, the researchers physiologically distinguish gendered behavior from biological sex. Hormones are a POTENT force underlying human sexual behavior and drive: Motivation for sex gendered behavior that facilitates sex

Body surface

primary somatosensory has a body map (homunculus) of the contralateral side of the body. Amount of space correlates with sensitivity in those areas, high in hands and lips. slide 8-9

Structure: spinal cord Medulla Oblongata Thalamus

spinal cord: Substance P: A peptide transmitter that is involved in pain transmission Glutamate and Substance P selectively boost pain signals and remodel pain pathway neurons Medulla Oblongata: When ascending pain signals cross the medulla oblongata, they can activate certain neural pathways of the autonomic nervous system Thalamus: The thalamus receives projections from multiple pain pathways -Processes nociceptive (harmful) sensory and motivational stimuli and then transmits that information to various parts of the cortex. (Aziz and Ahmad, 2006) -The habenula: in the posterior thalamus, connects forebrain structures, hypothalamic, and basal ganglia with brain stem structures that are important for processing pain modulation. (Shelton et al, 2012)