BIBB 109 Midterm 3
schizophrenia
"divided mind"; patients alternate between normal and abnormal states; characterized by loss of contact with reality; disruption of thought, perception, mood and movement
In general, what is the anatomy of the hippocampus?
It is made up of 3 layers, with 2 thin sheets of neurons folded onto each other. There is the dentate gyrus and Ammon's horn, made up of the CA3 and CA1 divisions.
____ MEC has finer grid spacing than ____ MEC.
Dorsal; ventral
Why is there lower hippocampal volume in PTSD?
During chronic stress, continuous exposure to cortisol can cause hippocampal neurons to die
What supports the Dopamine Hypothesis?
Effective treatments for the positive symptoms of schizophrenia block dopamine receptors (D2 receptors)
What does psychotherapy to treat affective disorders entail? In what cases is it used?
Efforts to overcome negative thought processes; for mild to moderate cases
How are EEG rhythms characterized?
By their frequency range
In the sympathetic division of the ANS, ganglia tend to be close to the ____, while for the parasympathetic division, ganglia tend to be close to the ____.
CNS; target
Describe the mechanisms of LTP in CA1.
Ca++ entering through NMDA receptors activates calcium-dependent protein kinases. Kinases change effectiveness of existing postsynaptic AMPA receptors by phosphorylating them. Kinases also stimulate insertion of new AMPA receptors into the membrane.
____ blocks adenosine receptors.
Caffeine
Why might the monoamine hypothesis drugs be legitimate?
It may be that the drugs promote long-term adaptive changes to the brain involving alterations in gene expression which alleviates depression.
Describe the study regarding proof of memory consolidation following sufficient sleep.
It tested people's improvement on a video game. Much improvement was shown for those who'd slept between the first and second session. Performance recovered and stabilized following sleep.
How does leptin act on the hypothalamus? Which specific parts of the hypothalamus respond?
Leptin released by adipocytes (fat cells) activate leptin receptors on neurons in arcuate nucleus of the hypothalamus. 1. the arcuate nucleus can sense leptin levels. It controls paraventricular nucleus and lateral hypothalamic area. Arcuate neurons responding to elevated leptin release the peptide transmitters αMSH and CART (anorectic peptides), which activate the paraventricular nucleus and inhibit the lateral hypothalamic area. 2. the paraventricular nucleus, which is part of the ANS and endocrine system, increases metabolism and increases energy expenditure. 3. the lateral hypothalamic area activates homeostatic motivated behavior (feeding); in this case, feeding behavior inhibited
What are the main diffuse neuromodulatory systems?
NE, serotonin (5HT), dopamine (DA), and ACh
How do NMDA receptors affect memory?
NMDA receptor dependent processes play a role in memory. Rats with NMDA-blocker (AP5, similar to APV) injected into hippocampus never learn the location of the platform. AP5 animals don't spend more time swimming in quadrant that had the platform like controls do
What peptide transmitters are released by arcuate neurons when leptin levels are decreased? What are the effects?
NPY and AgRP, which are orexigenic peptides Feeding behavior is stimulated. The lateral hypothalamic area is activated while the paraventricular nucleus is inhibited. An activated lateral hypothalamic area causes increased feeding behavior. The inhibited paraventricular nucleus lowers energy expenditure and metabolism.
Panic disorder may lead to _____.
agoraphobia
What is common in people with anxiety disorders? Why?
alcohol abuse; alcohol is sometimes used as self- medication because it has the same effect as benzodiazepines (binds to GABA A receptors)
Strabismus gives the same effect as what?What is it? What is this effect?
alternating deprivation; when the eye muscles are misaligned; all cells are either driven by the contralateral or ipsilateral eye, with very few binocular cells
Strabismus (eye misalignment) will lead to ____ (cortical ____ in the deprived eye) if not corrected.
ambliopia; blindness
Strengthening of synapses in developing V1 is thought to be mediated by what? Explain.
an NMDA-receptor dependent mechanism 1. Neighboring retinal ganglion cells tend to fire together leading to summation of synaptic inputs in target cells sufficient to raise Vm in cortical cells to a point where the Mg++ block in NMDA receptors is removed 2. Increase in [Ca++]in activates intracellular 2nd messenger systems leading to the strengthening of active synapses
Fear
an adaptive response to threatening situations expressed by the sympathetic division of the ANS; can be innate or learned
mood
an emotional state that is prolonged, one's predominant emotional state
What is the treatment for mental illness according to Skinner's theory of Behaviorism?
help patient "unlearn" through behavior modification
What is the treatment for mental illness according to Freud's theory of psychoanalysis?
help patient uncover secrets of the unconscious (e.g., physical, mental or sexual abuse) that often occurred during childhood and were suppressed from consciousness
EEG waves have ____ amplitude and ____ frequency as get into deeper sleep.
higher; lower
The _____ is involved in learning and memory, including spatial learning and memory
hippocampus
oxytocin
hormone that causes uterine contraction and milk letdown reflex; the love hormone (levels rise during sexual behavior; promotes social bonding)
What does the diencephalon consist of?
pineal gland, thalamus, subthalamus, and hypothalamus
What might border cells be important for?
planning trajectories and anchoring grid fields and place fields to a geometric reference frame
Antipsychotic drugs are most effective at diminishing ____ symptoms of schizophrenia. None of the medications reliably benefit the _____ symptoms.
positive; cognitive
PTSD
post traumatic stress disorder; Increased anxiety, intrusive memories, dreams or flashbacks of the traumatic experiences, irritability, or emotional numbness as a result of experiencing or witnessing a shocking event or events
You can think of development in the visual system as occurring in what 2 stages?
prenatal and postnatal development
Nondeclarative memory
procedural memory; memory for skills, habits, behaviors (e.g. riding a bike, playing an instrument)
The mature brain is precisely wired to do what?
process sensory information into coherent patterns of activity that form the basis of our perception, thoughts and actions.
List some treatments for affective disorders.
psychotherapy, antidepressant drugs, lithium, ECT (electroconvulsive therapy) of the temporal lobes, and deep brain stimulation
The amygdala and hippocampus regulate the HPA axis in ____-____ fashion. Anxiety disorders have been associated with ____ of the amygdala or ____ of the hippocampus.
push-pull; hyperactivity; hypoactivity
place cells
pyramidal neurons in the CA1 region of the hippocampus that are maximally responsive to specific locations in the world; serve as the output cells for the hippocampus
Where is the core of the 5HT neuromodulatory system?
raphe nuclei in brainstem
When the activity of the pyramidal cells is _____, there is a large fluctuation in the EEG ____ ____. This gives a large _____ EEG.
synchronized; voltage trace; amplitude
Diffuse modulatory systems control rhythmic behavior of the _____, and in turn EEG rhythms of the _____ _____.
thalamus; cerebral cortex
Spatial navigation requires what?
the ability to recall landmarks (external cues), and to rely upon internal (ideothetic) cues about self- movement and direction
Learning
the acquisition of new information or knowledge
Dopamine Hypothesis
the idea that schizophrenia involves an excess of dopamine activity; high doses of amphetamines can produce psychotic symptoms with positive symptoms identical to schizophrenia. Amphetamines (stimulants) enhance dopaminergic synapses causing release of dopamine
Glutamate Hypothesis
the idea that schizophrenia may be caused, in part, by understimulation or deficit of NMDA glutamate receptors
Anxiety disorders involve what?
the inappropriate and pathological expression of fear, which prevents normal function
energy balance
the intake of energy equals expenditure of energy
Memory
the retention of learned information
positive energy balance
the state in which energy intake is greater than energy expended, generally resulting in weight gain
negative energy balance
the state in which energy intake is less than energy expended, resulting in weight loss/starvation
How would APs change after a bilateral SCN lesion?
they lose their circadian rhythm
The walls of the ____ ventricle are made up of the hypothalamus.
third
What's another name for the sympathetic nervous system? Why?
thoracolumbar; the preganglionic neurons are located in the thoracic and lumbar regions of the spinal cord
What allowed rats to be trained to run on a wheel for 15 s?
time cells
What are some examples of ideothetic (internal) cues?
• vestibular signals detect movement in three dimensions • proprioceptive information from muscles (spindle) and joints (GTO) about limb position • corollary discharge from the motor system telling the rest of the brain what movements were commanded • Self-produced optic flow visual cues (produced by your own movement)
How is the radial arm maze done?
• At the start of each trial each arm is baited • Rat placed in center • Rats make a mental list of places it has visited • Rats learn to visit each arm only once
In the formation of ocular dominance columns there are 2 important mechanisms at work. What are they? What is the critical factor regulating both mechanisms?
• Competition for target space between fibers from the 2 eyes • Cooperation between fibers from the same eye neural activity
How is the circular platform maze done?
• Maze explores spatial reference memory on dry land like the water maze • Only one of the holes leads to a hidden tunnel beneath the maze • Rats don't like to be out in the open • Rat must learn location of hole leading to tunnel • Requires fixed cues outside the maze
How is the Morris water maze done?
• Rat are placed in circular pool of cloudy water • Rat must find hidden platform under surface of water • Rat learns to swim directly to platform • Platform remains in fixed position relative to visible cues outside pool • Remove platform and see where rats spend most of their time swimming • Divide pool into four quadrants • Rats spend more time swimming in quadrant that had been the site of the hidden platform
What occurs in postnatal visual development?
• The coarse pattern of connections that emerged during prenatal development is refined by activity dependent mechanisms • This activity dependent stage of development is based on interactions between the organism and its environment • The influence of the environment on the brain changes with age
What is a normal night's sleep?
•Adults 5-10 hrs •Young adults 6.5-8.5 hours
What occurs during REM sleep?
•An active, hallucinating brain in a paralyzed body •Dreaming sleep •EEG - almost indistinguishable from waking, fast, low voltage •Atonia, total loss of muscle tone •Paralysis - most of the body (except the respiratory muscles, inner ear muscles and eye muscles) is incapable of moving •Rapid eye movements (REM) •Increased sympathetic tone, increased and irregular heart rate and respiration rates
Which system is used for study because of its highly organized structure?
visual
allothetic (external) cues
visual, auditory, tactile, and olfactory cues
What does the normal stress response include?
- Adaptive response to real threat - Avoidance behavior - increased vigilance and arousal - Activation of sympathetic division of ANS - Release of cortisol from the adrenal glands - Usually transient
How is psychotherapy used to treat anxiety?
- Gradually expose the patient to the stimuli that produce the anxiety - Reinforce the notion that the stimuli are not dangerous
What factors can convert inherited genetic vulnerability into schizophrenia?
- New mutations - Epigenetics: how environment, nutrition and social conditions affect how genes are expressed - No single gene is responsible - environmental factors that could trigger schizophrenia if predisposed (drug use, difficult pregnancy/birth such as maternal infection during pregnancy or hypoxia during fetal development)
What are the symptoms of mania?
- Persistent abnormally elevated or expansive mood - Inflated self-esteem and grandiosity - Decreased need for sleep, increased talkativeness - Racing thoughts, distractibility - High impulsivity and increased reckless behaviors - Increased goal-directed activity - Onset tends to be rapid, often after sleep deprivation
What occurs in prenatal visual development?
- pattern of connections emerges as a result of cell recognition events. -A genetically programmed axon guidance mechanism gets axons in approximately the right place - There is a coarse retinotopic map, but the result is not nearly as good as normal retinotopy found in the adult.
Schizophrenia effects __% of the population. It's twice as common in ____.
0.5%; males
What are some symptoms of narcolepsy?
1. Excessive day time sleepiness-can lead to "sleep attacks" 2. Cataplexy-sudden muscle paralysis while consciousness is maintained, similar state as REM. Usually lasts <1 minute 3. Sleep paralysis-muscle paralysis occurring during the transition between sleeping and waking. Conscious but unable to move for several minutes 4. Hypnagogic hallucinations-graphic dreams, frightening, can occur at sleep onset, may follow sleep paralysis
how is necessary depolarization achieved with a tetanus?
1. High frequency stimulation causes temporal summation 2. Enough synapses must be active to cause spatial summation (cooperativity)
What were the assumptions of Freud's theory of psychoanalysis?
1. Much of mental life is unconscious (beyond awareness) 2. Past experiences, particularly in childhood, shape how a person will feel and respond throughout life
What are the microcircuits in the hippocampus?
1. Perforant path: Entorhinal cortex -> dentate gyrus 2. Mossy fiber pathway: Dentate gyrus-> CA3 3. Schaffer collateral: CA3 -> CA1
What are the 3 regions of the hypothalamus from medial to lateral? What nuclei/nucleus does each contain?
1. Periventricular area: periventricular nucleus 2. Medial Hypothalamic area: many well-defined nuclei 3. Lateral Hypothalamic area: lateral preoptic nucleus and lateral hypothalamic nucleus
What are the 4 regions of the medial hypothalamic area from rostral to caudal? What nuclei does each region contain?
1. Preoptic area: medial preoptic nucleus, lateral preoptic nucleus 2. Anterior (supraoptic) region: anterior hypothalamic nucleus, supraoptic nucleus, paraventricular nucleus, suprachiasmatic nucleus 3. Middle (tuberal) region: arcuate nucleus, ventromedial nucleus, dorsomedial nucleus 4. Posterior (mammillary) region: mammillary nuclei, posterior hypothalamic nucleus
How are ocular dominance columns visualized?
1. Radioactive proline is injected into the eye 2. Transsynaptic transport through LGN terminates in layer IVC of the primary visual cortex 3. Termination are visible as bright bands on the autoradiogram. Inputs from left and right eyes are completely segregated and generate ocular dominance columns.
What was the experiment that Hubel and Wiesel did to illuminate how OD columns are formed? What is true about this experiment if it's done on adults?
1. Suture one eye shut at birth 2. Raise monkey to ~6 months of age, remove sutures and test the deprived animalʼs visual responses 3. Observe responses: Retina: cells OK; responsive LGN: cells OK; responsive Striate cortex: cells can only be driven by non-deprived eye There is no effect is an adult is deprived.
How was long term potentiation of the the Schaffer collateral (CA3 > CA1) studied?
A brain slice preparation was done. After recording a baseline EPSP for a CA1 neuron, a tetanus (stimulus) is applied to the neuron. The EPSP then becomes greater and stays large after repeated stimulation (long term potentiation).
What 3 tasks are used to investigate spatial learning?
1. The radial arm maze 2. The Morris water maze 3. The circular platform maze
What does the hypothalamus control to mediate homeostasis? List how it is connected to what it controls.
1. autonomic nervous system: Projections to sympathetic and parasympathetic neurons 2. endocrine system: via anterior and posterior pituitary gland 3. motivated homeostatic behaviors (e.g., feeding, drinking, etc.): via connections with forebrain, limbic system, brainstem and spinal cord
What anxiolytic (anxiety-reducing) drugs are used to treat anxiety? How do they work?
1. benzodiazepines (Diazepam or Valium, Ativan (addictive)). They bind to GABA receptors (open Cl- channels > hyperpolarization) and enhance function and suppress activity in brain circuits including those used in stress response. 2. SSRIs (serotonin-selective reuptake inhibitors) (e.g., Celexa, Prozac (not addictive)). They prolong actions of 5-HT by blocking reuptake at the transporter. Takes a few weeks to become effective, at which point they increase the number of glucocorticoid receptors in hippocampus and increase neurogenesis in the hippocampus.
What are the two basic types of cues for navigation?
1. ideothetic (internal) cues 2. allothetic (external) cues
What are some theories for the biological basis of affective disorders?
1. monoamine hypothesis 2. Diathesis-stress hypothesis 3. Anterior Cingulate Cortex Dysfunction
How does the brain generate synchronous brain rhythms?
1. neurons take timing cues from a central pacemaker neuron (heart tissue) 2. Synchronous timing arises from the collective behavior of all the cortical neurons (mutually exciting and inhibiting one another)
Describe the HPA axis.
1. physiological or anxiety-like stress is sensed by the hypothalamus 2. corticotropic-releasing hormone (CRH) is released in the portal system by the parvocellular neurosecretory neurons and travels to the anterior pituitary. 3. Once CRH binds to cells with receptors for CRH in the anterior pituitary, the anterior pituitary releases ACTH (adrenocorticotropic hormone) 4. ACTH acts on receptors in the adrenal cortex. The adrenal cortex releases cortisol (stress response) 5. cortisol inhibits CRH release (negative feedback)
For a diagnosis of depression, symptoms must be present every day for at least ____ ____. Depression usually doesn't last longer than _____ _____.
2 weeks; 2 years
OCD affects ___% of the population equally in both genders.
2%
Panic disorder occur in ___% of the population and are more common in _____ or people who have some ____ ____.
2%; women; genetic predisposition
What is the critical period for the normal development of binocular vision in humans?
2-4 years
PTSD affects ___% of the adult population in the USA.
3.5%
Above and below layer ___, cells are binocular. It's important that neurons are binocular. This is the basis for ____, or ____ ___. Cells are ____ by one eye or the other.
4; stereopsis; depth perception; dominated
Without treatment, ___% will have recurrent depressive episodes.
50%
There is ___% of heritability of schizophrenia in identical twins. ____ factors are important as well.
50%; environmental
Depression occurs after a stressful life event in ___% of cases.
80%
sleep cycle
90-min cycle through REM and non-REM sleep (25% REM, 75% non-REM (4 stages)); ultradian rhythms (cycles repeated throughout a 24-hour circadian day.)
Describe what happens with a child with strabismus? (course of abnormality, treatment, etc.)
A child born with strabismus initially has good vision (acuity). However, because they cannot fuse the image in the 2 eyes, these children tend to favor one eye. Ophthalmologists used to delay correcting strabismus (surgically) until children were 8 or 9 years old - long after thecritical period. As a result, these children lost useful vision in the neglected eye (ambliopia). Because of Hubel and Wieselʼs animal models of strabismus and MD, ophthalmologists now treat strabismus very early, when normal binocular vision can be restored. For children with mild strabismus, patch good eye for a few hours/day to strengthen eye muscles for alignment. This forces use of eye becoming ambliopic. For children with mild strabismus, use surgical intervention to realign eyes
epilepsy
A condition where a person experiences repeated seizures; caused by tumor, trauma, metabolic dysfunction, infection, vascular disease, or genetic predisposition (mutated Na+ channels that stay open too long and make neurons hyper excitable, disruption of GABA mediated inhibition); upset in the balance of synaptic excitation and inhibition
mental illness
A diagnosable disorder of thought, mood, or behavior, which causes severe distress and impairs daily function
What type of neuron oscillator is the thalamic pacemaker neuron? Describe its action when one sleeps.
A one-neuron oscillator; The cortex receives input from the thalamus. A hyper polarizing stimulus goes to the thalamus. The thalamic neuron begins a burst mode of firing caused by depolarization. This is followed by inhibition. Thalamic relay cells can operate in rhythmic burst mode during sleep states. Their rhythmic activity is not shaped by patterns of retinal input.
How was it discovered that the hippocampus is involved in memory?
A young man suffering form epilepsy received a bilateral temporal lobectomy - Including the cortex, the amygdala and hippocampus - to alleviate seizures. He had partial retrograde amnesia for years preceding operation. He was unable to form new declarative memories (extreme anterograde amnesia). Only had a short working memory. This indicates that the areas that were removed from his brain, the hippocampus and parahippocampal regions, are essential for formation of declarative memories
Why does burst mode occur during sleep?
ACh, NE, or 5HT diffuse neuromodulatory systems depolarize thalamic neurons
Explain Glutamate receptor trafficking.
AMPA receptors are continually being added and removed from the membrane. LTD and LTP disrupt the equilibrium and lead to a net increase or decrease in AMPA receptors in the membrane. Newly formed AMPA receptors have GLuR1 subunit. During LTP, more newly formed AMPA receptors are inserted into slot proteins in the membrane. This also requires larger slot proteins to house the additional receptors. Thus, an LTP gives a new steady state with more AMPA receptors in the membrane. During LTD, there are fewer AMPA receptors in slot proteins in the membrane, and thus smaller slot proteins. Thus, an LTD gives a new steady state with fewer AMPA receptors in the membrane.
How were Hubel and Wiesel able to quantify ocular dominance?
Above and below layer 4, you find cells receiving inputs from both eyes (binocular), but they are generally dominated to some extent by one eye or the other. On the basis of responses to stimuli in the ipsilateral and contralateral eye, Hubel and Wiesel divided response properties into 7 ocular dominance groups. 7: cell driven only by ipsilateral eye; 4: cell driven equally by ipsilateral and contralateral eye; 1: cell driven only by contralateral eye
MAO inhibitors
Behavioral stimulants that reduce depression by inhibiting the action of an enzyme called MAO, which normally breaks down and deactivates norepinephrine and serotonin. This enhances NE and 5HT action by preventing synaptic destruction.
Activity in what area is increased by autobiographical recall of a sad event?
Anterior Cingulate Cortex
Why might the Anterior Cingulate Cortex affect depression?
Anterior cingulate has connections with amygdala and hippocampus
agoraphobia
Anxiety about, or the avoidance of, places or situations from which escape might be difficult or embarrassing, or in which help may not be available in the event of a panic attack
circadian rhythm
Any rhythm with a period of about 1 day
generalized anxiety disorder
At least 6 months of persistent and excessive anxiety and worry
obesity
BMI of 30 or higher
Explain why hippocampal synapses need to be modifiable.
Because grid cells differ in spacing, each place in the local environment is associated with a unique combination of active cells. Neurons with access to this combined activity could signal the animal's location (hippocampal place cells). Medial Entorhinal Cortex is one of the major inputs to the hippocampus. Because place fields can change in new environments, hippocampal synapses need to be modifiable
What type of lesion would cause rats to never remember the location of the platform in the Morris water maze?
bilateral hippocampal lesion
How does the brain maintain energy homeostasis?
Brain monitors amount of body fat to maintain normal levels of fat energy stores
How do orexins affect sleep? From where is it secreted?
Cell secrete orexin in the lateral hypothalamus. They strongly excite cells of the cholinergic, noradrenergic, serotonergic and dopaminergic modulatory systems. This promotes wakefulness and inhibits REM.
How do genes cause mental illness?
Certain genetic mutations can predispose or protect against psychiatric illness
Explain how the NMDA receptor is a coincidence detector?
Channel opens only when both pre and post synaptic elements are active (Hebbian learning). Pre synaptic cell is active - it's releasing glutamate. Postsynaptic cell is active - it's depolarized and therefore Mg++ block in NMDA receptor channel is removed. Na+ and Ca++ enter the postsynaptic cell. Increased intracellular Ca++ initiates a cascade of events leading to increased synaptic strength (synaptic efficacy).
REM-on cells
Cholinergic neurons of the pons, initiate REM; also part of the circuitry that inhibit spinal motor neurons and prevent us from acting out our dreams
How were place cells discovered?
Chronic recording electrode (measuring APs from place cells) implanted in rat's CA1 region by John O'Keefe and John Dostrovsky. Recording from single CA1 cell in hippocampus while freely moving rat move around in a closed space. LED was put on top of the rat's head detected by the camera. Computer keeps track of where the rat was when the cell fired. There is a white cue card inside the rat's enclosure to let the rat know where he/she is (external cue of location). When the cue card is rotates, the response field of the place cell changes.
_____ _____ mechanisms make it harder for teenagers to fall asleep early in the evening.
Circadian timing
Describe the setup of diffuse modulatory systems.
Core of each system has small set of neurons. Neurons of the diffuse systems arise from the central core in the brain. Each neuron in the core can influence many other neurons. Synapses can release transmitter into extracellular fluid and can diffuse to many neurons.
specific phobias
Clinically significant anxiety provoked by exposure to a specific feared object or situation, often leading to avoidance behavior
social phobia
Clinically significant anxiety provoked by exposure to certain types of social or performance situations, often leading to avoidance behavior
Hebbʼs Postulate for learning
Coincident activity in pre- and postsynaptic elements of a synapse leads to its strengthening (increased efficacy)
The autonomic nervous system is an ____ (efferent/afferent) system.
efferent
How was brain slice preparation used to study the Schaffer collateral?
Cut up piece of hippocampus and keep alive in a dish. Schaffer collateral synapses on to CA1 neurons used to study Long Term Potentiation, LTP. One electrode stimulates the axon collaterals projecting from the CA3 region to CA1 region and one electrode records intercellularly from one cell in the CA1 region to measure EPSPs at baseline.
What do antidepressant drugs do?
Dampen hyperactivity of HPA and anterior cingulate; increase neurogenesis in the hippocampus
As one falls asleep, what happens with the Ascending Reticular Activating System?
Decrease in firing rates of neurons of the Ascending Reticular Activating System may contribute to initiating non-REM sleep
What is used to treat affective disorders when all else fails? What does it entail?
Deep Brain Stimulation: stimulate anterior cingulate, recruits inhibitory neurons to reduce activity; electrodes left in place with battery-operated stimulator
What is the animal model used to study human anterograde amnesia? What type of lesion reduces performance on this task?
Delayed non-match to sample task (DNMS): An object is put atop an animal's food. The animal displaces the object to grab the food. A screen comes down to hide the food wells. A different object is placed over the well with the food in it. The task is to remember which object is different and move that object in order to get the food beneath it. Bilateral medial temporal lobe lesions
_____ is the most common mood disorder. It affects ___% of the population every year. ___%in the US will suffer from it at some point in their lifetimes.
Depression; 6%; 20%
What neural components control the sleep-wake cycle?
Diffuse modulatory neurotransmitter systems control sleep and waking. Locus coeruleus and raphei neurons fire during waking and enhance the awake state. They re a part of the NE and 5HT part of Ascending Reticular Activating System. Also, some cholinergic neurons can enhance REM events and others are active during waking
How does the hippocampus control fear?
It has glucocorticoid receptors which respond to cortisol. It suppresses CRH release in response to cortisol (negative feedback).
Zeitgebers
Environmental cues, such as the light-dark cycle, that entrain circadian rhythms to exactly 24 h; time givers
How can the environment cause mental illness?
Environmental stimuli (stress, drugs) can change how your genes are expressed
panic disorder
Frequent panic attacks consisting of discrete periods with the sudden onset of intense apprehension, fearfulness, or terror, often associated with feelings of impending doom
As one falls asleep, what happens with the Ventrolateral Preoptic area of hypothalamus (VLPO)?
GABAergic neurons inhibit ARAS and orexin neurons
What major psychiatric disorder afflicted 10-15% of institutionalized psychiatric patients in the early 1990s? What were the symptoms and what was it actually?
General Paresis of the insane; progressive, degenerative, involved mania and paralysis, ultimately death; syphilis
What are the main biological bases that underlie anxiety?
Genetic predisposition for many anxiety disorders or stressful life event
What types of cells are at work in spatial navigation in rats?
Grid, Border, Time, Head Direction, and Speed Cells
If one is awake or dreaming, what do the waves of the EEG look like? What type of waves dominate? How is one's cortical activity?
High frequency low amplitude waves; beta rhythms dominate; Cortical activity high and unsynchronized (see awake and REM sleep)
Why might the Diathesis-stress hypothesis support the idea that anxiety and depression coexist?
Hyperactivity of the HPA system (stress response system) is associated with anxiety disorders. Depressed patients also exhibit hyperactivity of HPA axis (elevated cortisol, elevated CRH, enlargement of the amygdala, reduced volume of hippocampus)
cognitive impairment
Impaired working memory and executive function - the ability to organize one's life; significant contributor to long term disability in schizophrenics
What is the evidence for competition for target space between fibers from the 2 eyes?
In MD, when one eye is closed, the competition is reduced Inputs from open eye form complete topographic map within the single neural space of layer 4c. In frog optic tectum, where processing occurs, no competition lead to no columns. This is because retinal ganglion cells cross in the optic chiasm and end up in the opposite optic tectum, so there's no competition in the optic tectum for target space. You can transplant a third eye onto the frog, which results in OD columns because two sets of ganglion from one side of the head project to the opposite tectum at the optic chiasm. Columnar organization results when 2 sets of afferent fibers are forced to compete for the same population of target cells.
How does deprivation change the dimensions of OD columns in layer 4c of V1?
In both cat and monkey, OD columns arenʼt there at birth and donʼt fully segregate until 13 weeks in cat. Initially you see projections from each eye spread out over the full neural space of layer 4. Each projection is trying to form their own topographical map of the retina. In an animal that has been monocularly deprived during the critical period, the deprived eye inputs to cortex are at a competitive disadvantage and therefore retract their inputs to an abnormal extent. Axon terminals from the non-deprived eye continue to occupy cortical space they normally would have given up to the other eye.
What led to the monoamine hypothesis?
In the 1960s, reserpine was used to control high blood pressure. Reserpine depletes monoamines dopamine, NE and serotonin. It caused depression in 20% of cases. Also, it was found that monoamine oxidase inhibitors (MAO inhibitors) used to treat tuberculosis causes marked elevations in mood.
How is a retinal flatmount used?
It does a multiunit recording. The top part of the eyeball is removed, leaving the bottom part of the eyeball with the retina. The retina is then cut so that it lies flat. Electrodes are placed in the retina to record from multiple retinal ganglion cells.
As one falls asleep, what happens with the sleep spindle?
It is generated by the inherent rhythmicity of thalamic neurons
What are the neurons that create circuity between the hypothalamus and posterior pituitary gland? Describe how it's connected. What hormones does it secrete and where do they go?
In the hypothalamus, there are neurons called magnocellular neurosecretory cells in the superoptic and paraventricular nucleus. These send their axons through the pituitary stalk. The axon terminals are in the posterior pituitary gland. They release hormones onto the capillary beds in the posterior pituitary gland. They release the hormones oxytocin and vasopressin. The hormones are released into the bloodstream, where they bind to receptors
What are the neurons that create circuity between the hypothalamus and anterior pituitary gland? Describe how it's connected. What hormones does it secrete? What is the entire system called?
In the hypothalamus, there are neurons called parvocellular neurosecretory cells in the paraventricular nucleus that secrete releasing hormones that travel in portal circulation to the anterior pituitary. The hormone are released to hormone-secreting cells in the anterior pituitary that have receptors for the hormones. Receptors for hypothalamic hormones cause anterior pituitary cells to release or stop releasing their hormones into blood. Their axon terminals are in the pituitary stalk. They synapse onto capillaries of the anterior pituitary. Hypothalamic pituitary portal circulation.
How does a precise retinotopic map and also segregation of L and R eye influences in 4c arise?
Initially there is a coarse map as both eyes try to generate a retinotopic map in the single layer 4c. Activity dependent processes of cooperation and competition follow Hebbʼs rule; sharpens terminal segregation. The course pattern of connection that emerged during prenatal development is refined by activity dependent mechanisms.
If one is in nondreaming sleep states or coma, what do the waves of the EEG look like? How is one's cortical activity?
Low frequency high amplitude waves; cortical neurons not engaged in information processing; large numbers of neurons excited by common slow rhythmic input; synchrony high, so EEG amplitude is high (see stages 1-4)
Why do we sleep?
Memory consolidation: verbal learning, spatial learning, sensorimotor learning
What are some disorders characterized by increased anxiety that are no longer classified by the American Psychiatric Association as "Anxiety Disorders"?
PTSD and OCD
Give 3 examples of treatment types developed from the monoamine hypothesis?
MOA inhibitors, tricyclics, and SSRIs
Where does the ventral tegmental area (VTA) project and what does it do?
Mainly to the frontal lobe; determines the nature of stimuli as rewarding or aversive and sends signals to the Nucleus accumbens
Freud's theory of psychoanalysis
Mental illness results when unconscious and conscious psyche are in conflict
What is the critical period for ocular dominance development?
Monocular Deprivation from birth to ~6 weeks in monkey; 12-13 weeks in cat, results in no binocular interactions. After this time period (the critical period) you get no effect of MD. The critical period is the time period in development when the genetically determined patterns of brain circuitry are particularly subject to environmental refinement. Here the cortex can change its wiring to appreciate the differential input from the two eyes.
Contrast the symptoms of a partial seizure occurring in the motor cortex vv sensory cortex.
Motor cortex - trigger, e.g. rhythmic movements of part of a limb Sensory cortex - trigger "aura" (abnormal sensation) e.g. odd smell or sparkling lights
The rat nervous system is highly adapted for what? Why?
Navigation through complex environments. Wild rats live in burrows and are generally nocturnal. When rats are kept in a semi-natural enclosure they dig underground tunnels and chambers for food storage and nests.
If you inject radioactive aa into newborn cat's eye, do you see ocular dominance columns? Explain.
No; only by 13 weeks of age do ocular dominance columns have essentially an adult pattern in mice.
REM-off cells
Noradrenergic and serotonergic neurons of the locus coeruleus and raphe nuclei, terminate REM
How is parabiosis done between two mice and what was the result when it was done with an ob-/ob- mouse and a wt mouse? What proof did this provide?
Parabiosis is the anatomical and physiological union of two animals in which they share the same blood supply. Ob-/ob- mice fused with normal mice have reduced feeding behavior and reduced weight; proof that communication from adipose tissue to brain was bloodborne (hormone)
Describe the biological clock experiment.
People were initially put on a light/dark cycle. Then, they were kept in the light all day. Their natural 24 h cycles shifts to a later time (free running circadian rhythms, rhythms not exact 24 h cycles). The people were then put back on a light/dark cycle. Their new circadian rhythm followed the last 24 h cycle that they were on (which was much later)
How does the SCN affect the other peripheral clocks?
Peripheral clocks are capable of maintaining their own circadian rhythms for only a few days. SCN controls ANS, body temperature, hormones and behavior and these processes regulate peripheral body clocks.
What drug is similar to oxytocin to cause uterine contraction?
Pitocin
How do place fields change?
Place cells' place fields are sometimes broadly responsive, sometimes focused point in space, sometimes more than one place.
___ cells appear to fire in specific places in environment. ___ cells fire at successive moments in temporally structured experiences. ___ direction cells fire to particular directions of head in the environment. ___ cells are excited at regularly spaced, multiple locations forming a spatial coordinate system. ___ cells firing rate correlates with speed of animal. ___ cells fire at boundaries in a number of environmental configurations.
Place; Time; Head; Grid; Speed; Border
Skinner's theory of Behaviorism
Pleasurable behaviors produce reinforcement and negative behaviors produce aversion. Mental illness occurs when maladaptive behaviors are learned.
What are the 3 clusters of schizophrenic symptoms? How do they differ?
Positive, negative, and cognitive; Each may reflect different aspects of the pathophysiology and each responds differently to medications
Describe the circuity of the autonomic nervous system.
Pre-ganglionic neurons from the parasympathetic and sympathetic autonomic nervous system send out axons to ganglia, which are outside the CNS. Pre-ganglionic neurons release ACh at ganglia. Ganglia send out axon to smooth or cardiac muscle or gland cells. Ganglia in the sympathetic division release norepinephrine, while those in the parasympathetic division release ACh.
Why is it that low increase in Ca2+ influx via NMDA receptors results in LTD and high increase in Ca2+ influx via NMDA receptors results in LTP?
Protein Kinases (phosphorylate proteins) are activated by high [Ca2+ ]in and yield LTP. Protein phosphatases (dephosphorylate proteins) are activated by low [Ca2+ ]in and yield LTD. Thus, AMPA receptors are dephosphorylated by stimulation that produces LTD.
What are the limitations of the monoamine hypothesis?
Prozac (Fluoxetine), selective serotonin reuptake inhibitor (SSRI) require weeks to achieve clinical efficacy, even though they have almost immediate effects at the modulatory synapses. They do not work in up to 40% of patients.
REM parasomnias
REM sleep behavior disorder; sleepers act out their dreams; sleep paralysis
Working Memory
lasts seconds; limited in capacity; requires repetition to hold the memory
Explain the experiment that suggested that early maternal care can reduce stress later in life.
Rat pups that receive a lot of maternal care have more glucocorticoid receptors in their hippocampus. Alternatively, tactile stimulation of rat pups activates serotonergic inputs to the hippocampus. Serotonin increases expression of the glucocorticoid receptor gene. More glucocorticoid receptors equip animal to respond to stressors as adults. Glucocorticoid receptors are on hippocampal neurons
What do rats do in maze learning?
Rat's establish a "cognitive map" an internal representation of the spatial attributes of the maze to solve the puzzle
What strategy do rats use to learn the radial arm maze?
Rats remember the position of arms by relating them to visible landmarks in the room. Rats develop a cognitive map of the maze by encoding spatial relationships between the different parts of it
What comes along with panic disorder?
Recurrent panic attacks, and persistent fear of panic attack, feelings of intense terror, palpitations, sweating, shortness of breath, chest pain, dizziness, tingling, chills or blushing
How can speed cells used to represent an animal's position for grid cells?
Running speed (cm/sec) is integrated across short time windows (sec) to obtain the instantaneous displacement (cm) of the animal, which, in conjunction with head direction input, is used to update the representation of the animal's position for the grid cells.
___ is the master clock (pacemaker).
SCN
What biological changes support the Neurodevelopmental Hypothesis?
Schizophrenia patients show reductions in brain volume and altered neural circuits, loss of dendrites and dendritic spines; also show loss of gray matter in parietal, motor, and anterior temporal cortex. Loss of gray matter is counterbalanced by enlarged ventricles.
What supports the Glutamate Hypothesis?
Schizophrenic patients have low levels of glutamate receptors. PCP ("angel dust") and ketamine ("special K"), are NMDA glutamate receptor antagonists, produces schizophrenia-like symptoms. Animal models of schizophrenia have diminished activation of NMDA receptors.
Explain and visualize how ocular dominance columns, which extend from pia to white matter, can be demonstrated anatomically or physiologically if there is monocular deprivation, binocular deprivation, and alternating deprivation.
Sensory deprivation alters the structure of the visual cortex. In MD, the deprived eye loses out in some sort of competition for target space. But the BD cat shows essentially no deficit. Compare the results of MD and BD you see that there is competition. The eye with more visual activity "wins" target space. In alternating deprivation, there are no binocular cells and the animal has no 3D depth perception. The effect of eye misalignment (strabismus) gives the same results as alternating deprivation.
What is the mind/body distinction and how made it up? Is it accurate?
Separation of the body and mind: the body could have physical ailments (physicians and medicine), but disorders of the mind were spiritual in nature (clergymen and religion); Descartes; no
What are the psychosocial approaches to mental illness?
Skinner's theory of Behaviorism and Freud's theory of psychoanalysis
NREM Parasomnias
Sleeper's brain tries to move from NREM to waking and becomes caught in between; Somnabulism - sleep walking; Night Terrors - more common in childhood. Screaming, temporary inability to regain consciousness
What is the reason for competition and cooperation for cortical targets?
Spontaneous firing of a group of fibers and the resulting synchronous excitation of the target seems to strengthen those synapses whose presynaptic fibers are active together (through cooperation) and to weaken those synapses whose presynaptic fibers are inactive or out of synchrony (through competition)
Describe the 4 stages of non-REM sleep.
Stage 1: •transitional sleep •Lasts only a few minutes Stage 2: •slightly deeper sleep •Lasts 5-15 minutes •sleep spindles (hi freq, low ampl) •generated by the thalamic pacemaker •K complexes Stage 3: •eye and body movements are few Stage 4: •deepest stage •large EEG rhythms
When do symptoms v. biological changes occur in schizophrenia?
Symptoms may not appear until twenties but biological changes causing the condition begin early in development, perhaps prenatally
Cooper and Monroe Model (BCM) for bidirectional synaptic plasticity
Synapses that are active when the postsynaptic cell is only weakly depolarized by other inputs will undergo LTD instead of LTP. Low increase in Ca2+ influx via NMDA receptors results in LTD; high increase in Ca2+ influx via NMDA receptors results in LTP.
What are the hypotheses for the biological basis of schizophrenia?
The Glutamate Hypothesis, the Dopamine Hypothesis, and the Neurodevelopmental Hypothesis
What governs the stress response? Explain?
The HPA Axis hypothalamus:In response to stress, secretes corticotropin releasing hormone (CRH) pituitary: In response to CRH, releases adrenocorticotropic hormone (ACTH) adrenal: In response to ACTH, releases cortisol
LTP is mediated by what?
The NMDA receptor, a glutamate receptor that is both a ligand (Glu) and voltage gated ion channel (at resting Vm, channel is blocked by Mg++, which is removed by depolarization when poise Mg2+ is repelled by cell being relatively positive inside; depolarization occurs when Glu ligand binds to AMPA receptors which opens Na+ to rush into cell), Na+ and Ca2+ entry through NMDA channels causes LTP. Thus, the channel opening is activity dependent.
Describe the animal study for energy balance.
The animal is first under a restricted diet. It loses body fat. Once free access to food is restored, animal will overeat until body fat restored. Then, the animal is under forced feeding. It gains fat mass. Once allowed to regulate its own diet, animal will eat less until fat levels return to normal.
homeostasis
The balanced functioning of physiological processes and maintenance of an organism's internal environment within a narrow range
What creates biological stress?
The brain in response to real or imagined stimuli. The brain stimuli causes the release of ACTH from the anterior pituitary, which binds to the adrenal cortex. The adrenal cortex releases cortisol during the stress response
What did O'Keefe and Nadel say about the hippocampus?
The hippocampus, with its place cells, is the site for a cognitive map. Responses of place cells are related to where animal thinks it is in its environment. The rat navigates its environment based on this cognitive spatial map in the hippocampus
What gene causes feeding behavior? Explain.
The ob gene codes for a protein, called leptin, which is released by adipocytes. Leptin is a hormone that communicates with the brain about fat reserves. Elevated leptin levels in blood activates hypothalamus and decreases feeding behavior. decreased leptin levels in blood activates hypothalamus and increases feeding behavior. Thus, there is communication from adipose tissue to the brain.
Diathesis-stress hypothesis
The proposal that says that genetic factors place the individual at risk while environmental stress factors transform this potential into an actual affective disorder. Life stress can dysregulate stress response systems.
What mode is the thalamic pacemaker in when you're awake? Describe it.
The tonic mode, in which there is no inhibitory firing and just a single AP
Neurodevelopmental Hypothesis
Theory proposing that schizophrenia is a disorder of development that arises during the years of adolescence or early adulthood due to alterations in the genetic control of brain maturation; early life stresses and in utero problems increase the risk of schizophrenia
How is the VTA involved in drug addiction?
There are opiate receptors and nAChRs for drugs such as heroine and nicotine. They stimulate DA release when the drug binds. On the nucleus accumbens, there are cocaine receptors. Cocaine prolongs the action of DA and enhances DA actions. This is why people find these drugs rewarding and addictive.
How does a two-neuron oscillator work?
There is a constantly excitatory cell giving input to another excitatory cell. The second excitatory cell synapses onto an inhibitory cell. The inhibitory cell synapses back onto the excitatory cell. Thus, when measuring the first excitatory cell, firing is constant. When measuring the second excitatory cell, firing begins at first and then stops when it's inhibited by the inhibitory cell. For the inhibitory cell, firing starts when its excited by the second excitatory cell, but stops when its activity stops the firing of the second excitatory cell.
Describe the flip-flop circuit for sleep.
There is mutual inhibition between sleep centers and waking centers. When you're asleep, the ventrolateral Preoptic area of hypothalamus (VLPO) is active. When you're awake, the lateral hypothalamus (orexin and ARAS) is inactive because they are inhibited by VLPO neurons. When you're awake, orexin neurons of the Ascending Reticular Activating system are active and excite ARAS. ARAS inhibits VLPO.
As one falls asleep, how is neural activity linked?
There is synchronization of activity during spindles and delta rhythms due to neural interconnections between thalamus and cortex
Why does the sleep-wake burst-tonic mode occur in the thalamic pacemaker neuron?
There's special ion channels that open when you're asleep v. awake because different inhibitory inputs arise
As one falls asleep, what happens with delta rhythms?
They are generated by the inherent rhythmicity of thalamic neurons
Why are the EEG rhythms useful?
They correlate with attentiveness, give information on sleeping/waking, and give information on seizures or coma
What allows the individual cells of the SCN to be biological clocks? Explain.
They have clock genes, which are transcribed into mRNA and translated into protein. After some delay, the translated protein feedback onto the clock gene and decreases transcription, which decreases gene expression. Then, less protein is produced so no negative feedback gene expression. This restarts a new cycle (24hrs). So in essence, a molecular cycle in their nucleus is based on gene expression.
What occurs in NMDA receptor knockout mice (NMDAR subunit knocked out)?
They have impaired LTP, less precise place fields in hippocampus, and impaired learning of water maze task
What occurs in CaMKII knockout mice? Why?
They have impaired LTP. They have fewer place cells found in hippocampus, less precise place fields, and less stable place fields. They also have impaired learning of spatial platform task. This is because CaMKII (Ca2+ /calmodulin kinase) is a Ca2+ -dependent kinase. They phosphorylate proteins and are activated by high [Ca2+ ]in and yield LTP.
What problem does Skinner's theory of Behaviorism and Freud's theory of psychoanalysis have in common?
They suggest that mental illness can be overcome by willpower alone (in contrast to physical illness)
Describe long-term depression in CA1.
To induce long term depression, input 1 axons are given a tetanus (brief burst of low frequency stimulation, e.g. 1 stimulus in 1 sec). What is required for LTD is that synapses be active at the same time that the postsynaptic CA1 neuron is weakly depolarized. The effect will be that EPSPs become smaller over the long-term.
Serotonin Selective Reuptake Inhibitors (SSRIs)
Treatment of clinical depression; rapidly elevate levels of serotonin in synapse by blocking reuptake of 5HT
What is the difference between Type I and Type II bipolar disorder? What is each's incidence?
TypeI involves mania with or without periods of extreme depression; effects 1% of the population. Type II involves hypomania with extreme depression. Hypomania is an increase in efficiency, accomplishment, and creativity; effects 0.6% of the population.
When is ECT (electroconvulsive therapy) of the temporal lobes used?
Used when suicide risk is high; immediate result
How was evidence for cooperation between fibers from the same eye obtained?
Using a retinal flatmount, you can visualize retinal ganglion cell firing. Each dot (pictured) represents an active cell. The size of the dot corresponds to the firing rate. Retinal ganglion cells are spontaneously active in utero. During 4 seconds of recording, a wave of spontaneous activity propagates from the lower right to the upper right of the retina. Neighboring cells in the retina tend to be active together, firing in synchronous bursts (lasting a few seconds). Neighboring cells would have similar patterns of activity (correlated activity). They project to the LGN and then to the cortex, so neighboring cells in these regions also have similar patterns of activity. Patterns in the two eyes would not likely be the same (uncorrelated activity).
What builds up when you're asleep? Explain
adenosine, a metabolite of ATP This seems to be a VLPO activator. The build up is indicative of neuronal depletion of energy stores. Adenosine has an inhibitory effect on the ARAS
When does schizophrenia start?
adolescence or early childhood
Because of syphilis, it is now acknowledged that all psychiatric disorders have what?
a biological basis: altered brain anatomy, chemistry and function
BMI
a measure of body weight relative to height; weight (kg)/(height)^2 (m^2)
Anxiety disorders
abnormal regulation of the emotion of fear
What does a electroencephalogram (EEG) measure and how?
activity of a large population of neurons; small voltage fluctuations are measured between appropriate electrode pairs; measures voltages generated by currents flowing during synaptic excitation of dendrites of many pyramidal neurons which are activated together. Very small electrical fields generated by many excitatory synaptic currents produce a signal. These electrical currents are due to positive current (Na+) flowing into dendrites at active synapses, leaving slight negativity. Current escapes near the soma leave fluid slightly positive.
The anterior cingulate cortex is an important link between what?
an internally generated emotional state and the HPA
What occurs when the blood is full of nutrients?
anabolism: storage of nutrients of glycogen in liver/skeletal muscle or as triglycerides in the adipose tissue
axis
anterior pituitary hormone system
vasopressin
antidiuretic hormone (ADH); regulates blood volume and salt concentration
What types of drugs are used to treat schizophrenia? Give some examples.
antipsychotic drugs
What are the most common psychiatric disorders?
anxiety disorders (15% of US population)
What are the broad categories of mental illness?
anxiety disorders, affective disorders, and schizophrenia
What is the 5HT neuromodulatory system involved in?
arousal, sleep-wake cycle, pain, mood
What is the NE neuromodulatory system involved in?
attention, arousal, and sleep-wake cycle
What are the 3 functional states of the brain? What does the EEG show on each?
awake: EEG low voltage and fast REM sleep: EEG looks like awake; body immobilized, dreams non-REM sleep: EEG high voltage and slow (slow wave sleep); 4 stages
What ACh core nuclei deteriorate in Alzheimer's?
basal forebrain complex
What was the assumption of Skinner's theory of Behaviorism?
behaviors are learned responses to the environment
Lithium is highly effective in ____ disorder.
bipolar
Human behavior is the product of ____ activity, which is a product of ____ and ____.
brain; genes; environment
What happens between meals?
catabolism: the stored glycogen and triglycerides get broken down to provide the body with a continuous supply of molecules for fuel
grid cells
cells found in Medial Entorhinal Cortex (MEC) of the hippocampus that are excited at regularly spaced, multiple locations as one moves around; allow animal to locate its body in a Cartesian-like external coordinate system
speed cells
cells in the MEC that exhibit a positive, linear response to running speed
Tricyclics
class of antidepressant drugs that increase the availability of neurotransmitters in the brain by interfering with the reuptake of these chemicals by transmitting neurons; enhance NE and 5HT
Short term memories are _____ into long term memories over time.
consolidated
Memory consolidation
converting memories into permanent form
Rhythmic activity in the thalamus drives rhythmic activity in the ____.
cortex
What's another name for the parasympathetic nervous system? Why?
craniosacral; the preganglionic neurons are located in the brainstem and the sacral spinal cord
ideothetic (internal) cues
cues that can tell the animal which direction it is moving, at what speed, and for how long. Provides basis for path integration - continuous integration of movement cues over a journey; tracking distance and direction to estimate your current position (and know how to get home)
aura
deja-vu, a feeling that something has happened before; hallucinations
Mood disorders generally involve what?
depression or elation
The hypothalamus is part of the ____.
diencephalon
What type of drugs were developed following the monoamine hypothesis?
drugs that elevate levels of serotonin, norepinephrine, or dopamine in the synapse
What brain part is our biological clock? How is it entrained? Explain.
each cell of the suprachiasmatic nucleus (SCN); Light sensitive input entrains the clock; light that entrains the cells comes from the retina, which contain ganglia cells, ipRGCs, that are intrinsically photoreceptive. Light-sensitive retinal ganglion cells have the visual pigment molecule melanopsin (not found in rods and cones). They project to the SCN.
Severe stress at which stage in life can put people at risk for development of mood disorders?
early in life
border cells
entorhinal cortex, sensitive to presence of borders; express proximity to boundaries in a number of environmental configurations
What influences the position of the place field?
external cues (landmarks in chamber) and internal cues: (visual (optic flow) cues, vestibular cues due to self-motion)
T/F? Depression most commonly precedes the onset of an anxiety disorder.
false
T/F? People with schizophrenia have the same life expectancy as people without schizophrenia.
false
T/F? The precise wiring of the brain is fully developed at birth.
false
monoamine hypothesis
hypothesis for the biological basis of affective disorders; Idea that mood disorders arose from depleted levels of serotonin and norepinephrine
negative symptoms
impairment of normal functions in schizophrenics; reduced expression of emotion (flat affect); withdrawal from social interactions; impoverished content of thought and speech; difficulty in initiating goal-directed behavior
Why might a panic attack occur?
in response to specific stimuli (triggers) or spontaneously
Where is the core of the NE neuromodulatory system?
in the brainstem (pons) in the locus coeruleus
Anterograde amnesia
inability to form new memories following trauma
Hypothalamic secretions of CRH (in the HPA axis) are regulated by what?
input from hippocampus and amygdala
Humans narcoleptics have ____ levels of orexin, not primarily due to genetics
low
What are some affective disorders?
major depression and bipolar disorder
The hippocampus projects to the ____ ____ by way of the _____.
mammillary bodies; fornix
bipolar disorder
manic-depressive disorder; mood disorder in which the person alternates between the hopelessness and lethargy of depression and the overexcited state of mania; characterized by cycling mood changes—from extreme highs (e.g., mania) to extreme lows (e.g., depression).
hypothalamus function
mediate homeostasis
Short term memory
memories that last on the order of hours
Long-term memory
memories you can recall days, months or years after they were originally stored
Declarative (explicit) memory
memory for facts (semantic memory) and events (episodic memory) (e.g. I had Cheerios for breakfast); spatial memory
Retrograde amnesia
memory loss for events before the trauma. Usually limited to loss of memory months or years before the trauma
generalized seizure
synchronization of firing involving entire cerebral cortex of both hemispheres
Both mood and anxiety disorders involve what? Why?
negative emotional states; they have overlapping neural circuits and overlapping risk factors
Head direction cells function as ____ ____ that signal the animal's directional heading to the navigational system
neural compasses
head direction cells
neurons in postsubiciculum of hippocampus that fire based on which direction an animal is facing; cells don't care where rat is, just what direction it's pointing; fire in same direction preference in familiar and novel environment
Which genotype of mice lacks both copies of the gene for leptin? What is their phenotype? Why?
ob-/ob-; they are obese because the brain thinks fat reserves are low
OCD
obsessive compulsive disorder; Obsession including recurring intrusive thoughts, worries, ideas, impulses, and images that the person perceives as being inappropriate, grotesque or forbidden that produces severe anxiety and compulsion including repetitive behaviors or acts to relieve the anxiety associated with obsessions to relieve the anxiety
What does the amplitude of the EEG depend on? Explain.
on how synchronous the activity of the underlying neurons is; the EEG picks up the sum of the activity from each individual pyramidal cell
Loss of ____ neurons leads to a sleep disorder called narcolepsy.
orexin
Disorders if REM control mechanisms involved what?
orexin: promotes wakefulness and inhibits REM sleep
What might be confused with a heart attack?
panic attack
What are some anxiety disorders?
panic disorder, agoraphobia, generalized anxiety, social phobias, and other phobias
Rats with bilateral hippocampal damage exhibit what behavior? What form of memory is this?
perseveration, repetition of choices, even when they are incorrect; spatial memory
In energy homeostasis, what does energy expenditure consist of? What are energy intake?
physical activity, diet induced thermogenesis (energy used in digestion, absorption, and nutrient distribution throughout the body), and basal metabolic rate (rate at which body uses energy at rest for vital functions); ingestion of protein, fats, and carbohydrates
insomnia
physical or emotional complications or poor sleep habits
What mental illness has the highest heritability?
schizophrenia
partial seizure
seizure involving only an isolated area of the cortex
What are the most extreme form of synchronous brain activity? What is this a sign of?
seizures; always a sign of pathology
major depression
severe symptoms that interfere with your ability to work, sleep, study, eat, and enjoy life; sad or empty feelings and decreased interest or pleasure in all activities; Overeating, or appetite loss, insomnia or excessive sleeping, fatigue, feelings of guilt and worthlessness, difficulty concentrating, recurrent thoughts of suicide, suicide attempts
Lesions in the hippocampus produce what?
spatial learning deficits and inability to form new declarative memories
In what season do most manic episodes occur? Why?
spring; light shifts
What does an inappropriate stress response entail?
stress that occurs when stressor is not present or not immediately threatening
Which division of the ANS is the fight or flight division? How about rest and digest?
sympathetic; parasympathetic
Positive (psychotic) Symptoms
symptoms of schizophrenia that are not present in healthy patients, but appear in schizophrenics; delusions (firm beliefs that are not realistic) often organized around a paranoid theme; hallucinations (usually auditory - hear voices, music)
What is required for LTP?
synapses be active at the same time that the postsynaptic CA1 neuron is strongly depolarized
The thalamus operates in ____ mode when awake and ____ mode when asleep.
tonic; burst
Emotions
transient responses to specific stimuli in the environment (danger), the body (pain), or mind (thoughts)
What does cortisol do?
transiently increases blood pressure, increases available blood glucose for fight or flight, increases vigilance and arousal in the brain, and reduces immune activity
T/F? 60% of patients with major depressive disorder also suffer from an anxiety disorder.
true
T/F? A depressive episode can occur only once in a person's lifetime, but more often, a person has several episodes.
true
T/F? Cell-death of orexin-containing hypothalamic neurons may be autoimmune process. This may be the cause of narcolepsy.
true
T/F? Cognitive impairment is also seen in healthy relatives of patients with schizophrenia.
true
T/F? Increased resting state activity in the anterior cingulate cortex has been observed in depressed patients. Activity decreased following successful treatment for depression.
true
T/F? LTD and LTP are input specific. Input 2 does not show an LTD or LTP.
true
T/F? Nearly every cell in the body, including those in the liver, kidney and lung, has a biological clock. They have the same gene transcription feedback loops drive the clocks in these peripheral tissues as the SCN.
true
T/F? People with depressive illnesses do not all experience the same symptoms. The severity, frequency, and duration of symptoms vary depending on the individual
true
T/F? Place cells are stable over time
true
T/F? The higher the hippocampal column, the longer people last as taxi drivers.
true
T/F? The sympathetic and parasympathetic nervous systems tend to have opposite effects.
true
How do rats code for head direction?
using internal cues and external cues
What does psychotherapy rely on? Is this appropriate for all mental disorders?
verbal communication to help the patient; no
What are the types of EEG rhythms? (give hertz range and characteristics)
•Gamma rhythms 30-90 Hz very attentive cortex •Beta rhythms >15-30 Hz signal activated cortex •Alpha rhythms 8-13 Hz drowsiness or relaxation •Theta rhythms 4-7 Hz occur during some sleep states •Delta rhythms <4Hz deep sleep
What occurs during non-REM sleep?
•Period for rest •Muscle tension reduced, minimal movement •Increased parasympathetic tone: heart rate, respiration, kidney function slow down •Digestive processes speed up •Slow firing rates of neurons •Slow, large amplitude EEG - neurons firing synchronously •An idling brain in a movable body
What occurs between REM and non-REM sleep over the course of the night?
•Reduction in duration of non-REM sleep •Increase in duration of REM sleep •Each REM is followed by at least 30min of non- REM
What does homeostasis control?
•Temperature •Blood volume •Blood pressure •Salinity •Acidity •Blood O2 •Blood glucose
Where are the two cores of the ACh neuromodulatory system? What are each involved in?
•basal forebrain complex: arousal, sleep-wake cycle, learning and memory •Parabrachial nucleus pons: regulates excitability of sensory thalamic nuclei
What are the functions of cortisol?
•releases glucose into your bloodstream •increases blood pressure for increased physical activity such as running or fighting •Stimulates brain for more intense awareness. •Immune system activity is reduced to save energy for physical activity
Where are the two cores of the DA neuromodulatory system? What are each involved in?
•substantia nigra: facilitates initiation of movement •ventral tegmental area: reinforces adaptive behaviors (rewards)
Each module grid scale is equivalent to the previous scale multiple by ____ or ____.
√2 or √e (Balasubramanian)
