Brain and Behavior Test 1
Sherrington inferred the presence of a gap between neurons based on ____.
A slower than predicted speed of conduction
Resting Membrane Potential
-70mV The inside of the axon is negatively charged with respect to outside Membrane potential: Electrical charge across a cell membrane, the difference in electrical potential inside and outside the cell Resting potential: Membrane potential when the neuron is not being altered by excitatory or inhibitory postsynaptic potentials, about - 70 mV Inside of the cell is negative with respect to the outside Membrane is polarized (carries a charge) What factors lead to the resting potential: The cytoplasm and the fluid outside the cell contain ions Ions are positively or negatively charged The concentration of ions is different within the cell (intracellular fluid) and outside the cell (extracellular fluid) Two Forces: Diffusion: Particles tend to move down their concentration gradient Electrostatic pressure: Like repels like, opposites attract Ions with the same charge repel each other, ions with opposite charges attract each other Positive electromagnetic force attracted to negative electromagnetic force
Schizophrenia
= too much dopamine (High global dopamine levels) Antipsychotics antagonise DA2 (dopamine 2) receptors The more potent the blockade of DA2, the better the outcome Drugs that block D2 receptor decrease schizophrenia symptoms Treatment with drugs is so effective, it is unethical not to recommend drug treatment for schizophrenia Amphetamines or cocaine + schizophrenia = even worse symptoms Regular person on amphetamines or cocaine can act schizophrenic Antipsychotic drugs : DA2 receptor antagonists Block DA2 receptors and prevent activation Some drugs increase global dopamine levels High doses produce psychosis (schizo-like symptoms) Cocaine and amphetamine both block the reuptake of dopamine Can cause stimulant psychosis Cocaine: inhibits dopamine reuptake - greater dopamine transmission Amphetamine: Inhibits dopamine reuptake - causes release- greater dopamine transmission
Santiago Ramón y Cajal
Able to stain sections of tissue from brain: allowed you to see individual neurons Allowed people to see that neurons functioned independently Used Golgi stain to prove "neuron doctrine" (brain as one unit or neurons independent?) Neuron is the smallest individual unit of the nervous system
Epinephrine and norepinephrine are produced in the ____.
Adrenal Medulla Epinephrine (adrenaline) and norepinephrine (noradrenaline) are both produced in the adrenal medulla. Epinephrine is release by the sympathetic nervous system, and norepinephrine is released by the parasympathetic nervous system.
Drug Actions
Agonist: Activates receptor fully Partial agonist: Activates and blocks receptors (has agonist effect, but to a lesser degree) Binds to receptor and does activate it, but not fully. Not exactly the right shape, but pretty close Neurotransmitter can't fully bind Both activating and blocking at the same time Antagonist Competitive: Blocks receptor Non-Competitive: Blocks channel Can be permanent, once blocked, receptor will never function again (doesn't have to compete- sodium channel blockers) Indirect action Block reuptake Block/facilitate breakdown Disrupt transport or packaging Alter release
Genetics
All of our genetic information (genes) are encoded on our chromosome Our chromosomes provide instructions on how to build everything our body needs and when to build what Autosomal cells (not sex cells)- infromation in nucleus in pairs (chromosomes) 1-22, organized by size (pair 1 is longest) and 2 sex chromosomes (46 chromosomes total) Last pair are sex chromosomes Deoxyribonucleic acid composed of 4 nucleic acids Adenine, matches to thymine Guanine matched to cytosine DNA: Self replicating molecule Each base determines one base of the RNA RNA: Copy of single strand of DNA that can serve as a tempete/model for the synthesis of proteins A triplet of bases determines one amino acid Genetic materials purpose is to produce proteins, which depend on what amino acids/order of amino acids are used Proteins determine the development of the body by: Forming part of the structure of the body and Serving as enzymes, biological catalysts that regulate chemical reactions in the body Human reproductive cells have half the number of chromosomes (23) Hemizygous: Only one sided needed, or missing gene on one side of chromosome pair - have gene on one side, not on other Allele: Format of gene- what variation you have: we could have the same gene, but different alleles (Homozygous or heterozygous) Genes Are either dominant recessive, or intermediation Sex limited genes are genes that are present in both sexes but mainly have an effect on one sex (Chest hair, breast size, etc) Heritability refers to how much characteristics depend on genetic differences Estimates of hereditary influence are often difficult to infer and are prone to error Genes do not directly produce behaviors, Genes produce proteins that increase the probability that a behavior will develop under certain circumstances Genes can also have an indirect effect Do we ever get new genes? Genes can change throughout lifetimes - mutations
Pons
Along with medulla (part of hindbrain), the pons contains the reticular formation and raphe system -Pons: Increase arousal and readiness of other parts of the brain/ regulates sleep/waking/arousal Two systems within pons: -The reticular formation (AKA reticular activating system): sends and receives info in two directions-separates sleep from awake Descending portion: Control the motor areas of the spinal cord Ascending portion: Selectively increasing arousal and attention by activating cortex -The raphe system also modifies the brain's readiness to respond to stimuli
In which neurotransmitter category does GABA belong? a. monoamines b. neuropeptides c. amino acids d. purines
Amino acids stands for gamma-aminobutyric acid, is an inhibitory neurotransmitter in the nervous system. It is considered an amino acid neurotransmitter that binds to an ionotropic receptor, which allows Cl- to enter the cell. Most prevalent inhibitory neurotransmitter in the brain Ionotropic and metabotropic receptors Gaba secreted by "local" interneurons all over the brain Works as an off switch Implicated in relaxation/anti-anxiety Many drugs of abuse enhance GABA: Benzodiazepines Xanax, klonopin, valium, librium Barbiturates Secobarbital,phenobarbital ALCOHOL All reduce anxiety, produce sedation High dose can cause anesthesia, coma, or death Gabaergic drugs: GABA receptor agonists Bind to GABA receptor and activate or enhance result of activation GABA has five different subunits that come together to make receptor (each can have their own binding site- creates opportunities for multiple drugs to have effect on same receptor- explains why combo of GABA drugs is especially problematic)
Anandamide
Anandamide Acts on "cannabinoid" receptors THC from marijuana mimics anandamide - agonist for cannabinoid receptors
Antidepressants
Antidepressants woke by increasing monoamines by : Blocking reuptake (Prozac, SSRI - serotonin reuptake inhibitor) Blocking Deactivation (MAOIs (monoamine oxidase inhibitor = enzyme that breaks monoamines down) block the breakdown of monoamines- work on NE and DA, or all three transmitters) MAOIs have problematic side effects: Build up of other monoamines (tyrosine) - can cause cardiovascular problems (heart attack, stroke, death) Antidepressants = delayed result - change in depressive individual happens down stream? Neurogenesis: birth of new neurons: individuals who are depressed make fewer new neurons Antidepressants: Reuptake inhibitors (Serotonin, NE, DA) Prevent transmission reuptake Monoamine Oxidase Inhibitors: Presents inactivation of monoamines
Which type of glial cell wraps around the presynaptic terminals of a group of functionally related axons?
Astrocytes Astrocytes wrap around the synapses of functionally related axons. This creates a shield from chemicals circulating in the surround. Also, they help take up the ions and transmitters released by axons. Astrocytes synchronize the activity of the axon by taking up chemicals released by the axon -Synchronize activity for group of neurons
Three Types of Glia
Astroglia (), oligodendroglia (produce myelin sheath), microglia (remove waste/harmful microorganisms) All exchange chemicals with adjacent neurons These three are found in brain, theres also Schawnn cells, which are found outside the brain
A(n)____ conveys an impulse toward other neurons, an organ, or a muscle.
Axon
Action Potential
Axon produces action potential when membrane's potential reaches the threshold First part of action potential: Sodium floods in, then as cell starts to become positively charged (-70 up to positive), then potassium channels open, and potassium flodos out (Potassium is also positive) - when positive potassium leaves, it brings charge back down into negative territory (below -70) - period where it is below -70 (overshot mark) cell is called Hyperpolarized (more difficult for neuron to fire action potential again - during the first half of this, its actually impossible) Polarized = negative charged Depolarized = fires an action potential, goes back to zero, and a little bit past it (positive) - no big charge in one direction or the other Hyperpolarized = back to negative potential, but overshot All neural communication depends on the transfer of ions across membranes Without ion transfer there is neural communication thus no behavior Intracellular fluid has higher levels of Organic anions (can't leave cell) )A-) Potassium Ion (K+) Extracellular fluid has higher levels of Chloride ions (Cl-) Sodium Ions (Na+) Both of the forces for sodium tell it to go in the same direction - wants to diffuse inside, and its positive, so it's attracted to inside of cell Negative charge inside is due to amount of negatively charged particles The membrane is selectively permeable, allowing some chemicals to pass more freely than others Sodium, potassium, calcium, and chloride pass through channels in the membrane When the membrane is at rest: Sodium channels are closed Potassium channels are partially closed, allowing the slow passage of sodium How does Na+ stay in highest concentration outside cell when both forces try to drive it in? Sodium potassium pumps constantly pump it out At rest, the membrane potential of a neuron is NEGATIVELY CHARGED Process of becoming more positive = depolarizing
What structure(s) is/are implicated in movement disorders like Parkinson's and Huntington's?
Basal Ganglia Motor planning - Important for aspects of movement Receives input from substantia Nigra Important for selection of willful movement Receives signals to do different things at the same time - allows selection Actually several structures in one label
Hindbrain
Basic bodily function -Medulla -Pons -Cerebellum Hindbrain, midbrain, and central structures make up the brain stem Earliest evolved - lower centers, around and above spinal column Pons Cerebellum - involved in timing, physical coordination (Helps regulate motor movement, balances and coordination - also important for shifting attention between auditory and visual stimuli)
Neuropeptides are characterized by ____. a. being released by a single action potential b. being synthesized in presynaptic terminals c. being released mostly from dendrites d. having an action that lasts, at most, a few seconds
Being released mostly from dendrites Larger neurotransmitters are synthesized in the cell body and transported down axon Neuropeptides: Enkephalin Often referred to as neuromodulators, neuropeptides have properties that set them apart from other transmitters. Unlike most, neuropeptides are made in the soma and released mainly by the dendrites.
The question of how various brain areas combine to produce integrated behavior and experience is referred to as the ____.
Binding Problem
Hippocampus
Critical for forming new memories Henry Molaison Hippocampus not important to remember events that happened long ago, but with damage, you can't form new memories
cerebrospinal fluid (CSF)
Central canal: Fluid filled channel in the center of the spinal cord Ventricles (contain csf): four fluid filled cavities within the brain containing cerebrospinal fluid (CSF) Cerebrospinal fluid: Clear fluid found in brain and spinal cord Provides cushioning for the brain Reservoir of hormones and nutrition for the brain and spinal cord Schizophrenia decreases brain mass, but you don't just end up with blank space, these ventricles enlarge to push brain and maintain firm fit Produced by choroid plexus (Lining of ventricles) - releasing of new CSF allows for circulation through system (no pump or anything)
Cerebrospinal fluid is produced by cells called the ____.
Choroid Plexus
Central Nervous System (CNS)
Consists of the brain and spinal cord Other half of nervous system (along with PNS) The Spinal Cord: Communicates with the sense organs and muscles below the level of the head Sensory information comes in on dorsal side of our spinal cord, whereas motor neurons emerge from the ventral side
Midbrain
Coordinates movement with sensory input Tectum: Root of the midbrain Superior (visual) and inferior (auditory) colliculus (Help us orient towards stimulus in space) Tagmentum: The intermediate level of the midbrain contains nuclei for cranial nerves and part of the reticular formation Substantia Nigra: produces dopamine neurotransmitter (facilitates readiness and movement/critical for initiating movement)
The surfaces of ____ are lined with synaptic receptors that receive information from other neurons.
Dendrites
A motor neuron, with its soma in the spinal cord, receives excitation through its ________
Dendrites: A motor neuron receives excitation through its dendrites and conducts impulses along its axon to a muscle.
Parts of a neuron
Dendrites: Branching fibers bringing info into neuron - Some contain dendritic spines that further branch out and increase surface area Soma/ Cell body: Contains nucleus, mitochondria, ribosomes, and other structures - also responsible for metabolic work of neuron Presynaptic terminals (receptor sites) Dendrites (receives message), soma (cell body), myelin sheath (fat wrapped around axon), axon (transmitting element), terminal buttons
One of the classic studies to demonstrate synaptic organization and change related to experience was done by looking at __________ in animal models. The more stimulating the environment, the more change that was seen.
Dendritic branching
Camillo Golgi
Developed staining technique that made only a fraction of cells visible Silver stain/black stain
Peripheral Nervous System (PNS)
Divided into somatic and autonomic nervous system Autonomic nervous system (ANS): Regulates function of organs/organ control - one nerve present in ANS = vagus nerve - Regulates the functioning of organs (Automatic functions = heartbeat) Sends and receives messages to regulate the automatic behaviors (heart rate, BP, respiration,digestion, etc) -Divided into sympathetic and parasympathetic Nervous System Sympathetic Nervous system: Controls "fight or flight" response -Think of being startles-Increases heart rate, blood pressure, respiration -Activated by acetylcholine -> releases norepinephrine onto organs -Gives us alertness and activity Parasympathetic -Acetylcholine onto Vagus nerve to slow heart down -Non Emergency response eating and relaxing Somatic nervous system: Muscle control and sensation -All of the nerves that allow us to move muscles and feel things -Receives sensation, controls muscles -Soma = body
Tommy is addicted to smoking cigarettes and says he really enjoys smoking. Smoking cigarettes feels rewarding in part because it triggers the release of ____.
Dopamine
The cell bodies of the sensory neurons are in clusters of neurons outside the spinal cord called ____. a. basal ganglia b. spinal ganglia c. dorsal root ganglia d. somatic ganglia
Dorsal root ganglia The dorsal root ganglion transmits what kind of information? Sensory Bell-Magendie Law: Entering dorsal roots carry sensory information and the exiting ventral roots carry motor information Dorsal root ganglia cell bodies of sensory neurons located in clusters of neurons outside the spinal cord Ventral side more protected, so important stuff is there Injury to dorsal side of spine = sensation damage, but injury to ventral side of spine = loss of ability to move
Brain Machines
EEG = Electroencephalogram - Gross electrical activity in the brain (detects electrical signals coming through skull, very sensitive according to time, but you don't know where signal is originating from - not very precise in terms of location) CAT= Computerized axial tomography : 3D X-Ray (X-ray sent through head, all this provides us with is structural image - dont get to see changes across time - good to see damage across brain) PET = positron emission tomography Measures positron emitting tracers (E.g glucose) Uses radioactive substance injected into body - can be designed to bind to certain things (like only dopamine) Can tell you where different proteins are residing Expensive and difficult Functional Magnetic Resonance imagery (fMRI) Maps changes in blood flow over structural images (blood contains iron = magnetic resonance) EEG very precise in terms of time, fMRI you can't see changes that quick (less temporal precision), but with fMIR you get great localization, with EEG you dont really know where signal is coming from
The primary motor cortex is in the ____ lobe of the cerebral cortex.
Frontal Phineas gage: Frontal lobe damage altered his personality Planning of movements, some aspects of emotions, Thinking and reasoning abilities, memory, executive function Precentral gyrus: Primary motor cortex responsible for the control of fine motor movement
Which is not a monoamine, but is a catecholamine?
Epinephrine = not a monoamine, but it is a catecholamine
Evolution
Evolution refers to a change in the frequency of various genes in a population over generations Regardless if helpful or harmful to the species Evolution attempts to answer two questions: How did species evolve? How do species evolve? How does evolution occurs Certain individuals successfully reproduce more than others do Artificial selection refers to choosing individuals with desired traits and making them parents of the next generation Evolutionary psychology: Focuses upon functional and evolutionary explanations of how behaviors evolved Assumes that behaviors characteristic of a species have arisen through natural selection and provide a survival advantage An organism with a short reproduction cycle is able to change through natural selection ----------- than an organism with a long reproduction cycle. FASTER *Some behaviors are more debate regarding the influence of natural selection Examples: Life span length: Living longer doesn't help us reproduce, so why are we living longer? Gender differences in sexiual promiscuity Altruistic behavior- a behavior that benefits someone other than the actor- why do we do nice things for people? Explanations: Reciprocal altruism (Perhaps in the future they can help me out) and kin selection
____________ refers to bursts of release of neurotransmitter from the presynaptic neuron.
Exocytosis Within 1 to 2 ms after calcium enters the axon terminal, the vesicle fuses with the cell membrane to release the contents into the synapse (a form of exocytosis).
ionotropic receptors
Fast receptors Close or open ion channels Can alter the charge (+/-) of the cell Opening allows certain things into post synaptic cells All it takes is a neurotransmitter to bind to them, and then immediately they open
Nitric oxide is an example of the ____ category of neurotransmitters.
Gases One of the few examples of a reverse action transmitter: Release by post synaptic neuron, travels to pre synaptic neuron
Most of the brain's excitatory ionotropic synapses use the neurotransmitter ____.
Glutamate The workhorse of the neurotransmitters Most prevalent EXCITATORY NT Some glutamate receptors can also cause inhibition AMINO ACID transmitter Has both Ionotropic and metabotropic receptors Everywhere in the brain Impacts a variety of functions, but can get out of control: can cause toxicity Blocking glutamate receptors after a stroke Involved in everything, but especially important in the formation of memories Can be highly toxic when out of control Whether something is excitatory or inhibitory effect depends on the type of receptor thats present on tissue AMPA Receptors: Allow Sodium (Na+) in NMDA receptors: Allows positive calcium in, cause long lasting changes Calcium will interact with other messenger proteins within cell to cause signaling cascade - new protein gets made from DNA, and neuron becomes exceptionally excited Mechanism of plasticity Can cause structural changes (grow more dendrites, add spines to dendrites) NMDA receptor blockers:Shut down communication Phencyclidine: "PCP" "Angel Dust" Ketamine: "Special K" Activation of receptor through drugs = perceptual changes (changes in viewing/feeling of body), changes in how you perceive time, delusions Psychotomimetic: mimic schizophrenia NMDA receptor antagonists Prevent glutamate from interacting with NMDA receptor/blocks the function of glutamate Used as an analgesic and anesthetic Both hallucinogens and anetherics Induces amnesia and true psychosis Hallucinations, paranoia, agitation, dissociation Higher doses lead to stupor, coma, seizures, death Sensations of light coming through the body, colorful visions, bizarre distortion, altered perceptions, sensation of floating or hovering, feelings of leaving one's body, visions of spiritual/supernatural beings, emotions ranging from euphoria to hostility
Common Misconceptions about evolution
Lamarckian Evolution: "The use or disuse of some structure or behavior causes an increase or decrease in that behavior" Not really true, but there are some exceptions Epigenetics (Epi means above or beyond) May not be changes to genetic code, but experiences can change our access to our DNA Locking Histone Spools: Chromatin wound around histones- each histone has tail-when we access DNA to make protein, we unwrap it- histone spools can become locked preventing us from being able to unwind portion of DNA and create protein from it (State of your histone can also be passed onto your children- If your histones get locked, the locked histone could be passed onto your children) "Humans have stopped evolving" "Evolution means improvement" Improves likelihood of reproduction, not necessarily that an organism is getting better, just means pressures of environment are changing Evolution benefits the GENE not the individual What benefits the reproduction of the gene may not be good for the individual (The Selfish Gene) "Evolution acts to benefit the individual or the species" "How could something as complex as a human develop through mutations?" "Irreducibly complex: It's so complicated it had to be assembled all at once"
Grey Matter VS White Matter
Grey: mostly cell bodies in spinal cord White matter: axons (covered in myelin sheath, makes it look white) Myelinated axons that carries information from the gray matter to the brain or other areas of the spinal cord
Pituitary Gland
Hormones: Chemicals secreted into the blood that travel to and effect distant organs Endocrine glands are responsible for the production of hormones The pituitary gland is attached to the hypothalamus (base of the brain) and consists of two distinct glands that each release a different set of hormones: 1. Anterior pituitary- Composed of glandular tissue and synthesizes 6 hormones (front part) - can release hormones into bloodstream 2. Posterior Pituitary- composed of neural tissue and can be considered an extension of the hypothalamus (made of neurons, aid in signaling) Pituitary Hormones Oxytocin: Orgasam, attachment, birth, breast feeding Vasopressin: Blood pressure Alters kidney functioning
Following a stroke, Mr. Smith suffered damage to his ____. His doctors warned his family that he might now have alterations in motivated behaviors like hunger, thirst, and sex.
Hypothalamus The hypothalamus also secretes releasing hormones -Flow through the blood and stimulate the anterior pituitary to release a number of other hormones Conveys messages to the pituitary gland to alter the release of hormones Associated with behaviors such as eating, drinking, sexual behavior, and other motivated behaviors Damage = changes in eating behavior and temperature regulation Hypothalamus and thalamus together form the "Diencephalon"
The cerebral cortex is organized in six layers of cell bodies called ____, which are parallel to the surface of the cortex.
Laminae Cerebral cortex: Outer surface of the brain Divided into two halves Six distinct laminae (layers) that are parallel to the surface Cells of the cortex are also divided into columns that lie perpendicular to the laminae
Dendritic Spines
Increase the surface area available for synapse
Internal Structure of Neuron
Internal structure of neuron: Cytoskeleton Cytoskeleton: Formed of microtubules and other protein fibers giving the cell its shape Microtubes: Long strand of bundles of protein filaments arranged around a hollow core; involved in transporting substances in the cell Axoplasmic transport: Active process by which substances are propelled along microtubules
__ is thought to help control appetite by decreasing it.
Leptin Leptin is produced by fat cells and helps to decrease appetite and increase activity levels.
Which of the following classic researchers is credited with demonstrating the existence of chemical synapses?
Loewi Otto Loewi was working with the vagus nerve and dissected frog hearts. He discovered that a chemical (that we now know is acetylcholine) was released by neurons to stimulate other neurons. Soupers VS Sparkers Sparkers: Believed that electrical signals were sent from one neuron to the other as a means of communication (incorrect) Soupers: believed chemicals were sent from one neuron to the next (correct) Sir Henry Dale and Loewi Otto demonstrate that communication at the synapse is chemical Loewi demonstrated that acetylcholine (used in all muscle junctions) released from the vagus nerve slows heart rate Two years after winning the Nobel prize, Loewi was thrown in jail by Nazis Later released after he gave them his prize money, then fled to US Loewi demonstrated that acetylcholine released from the vagus nerve slows heart rate Dale and Otto demonstrate that communication at the synapse is chemical
Drugs
Many hallucinogenic drugs work by altering monoamine transmission Produce perceptual disturbances Hallucinations, delusion, altered perception of time and space LSD (Acid), DMT, and psilocybin (mushrooms): All bind to serotonin (5-HT) 2A receptors MDMA (ecstasy) and peyote (mescaline): Increase serotonin, dopamine, and norepinephrine transmission Opioid/Endorphin system (receptors called opioid receptors) Discovered as a result of the pain relieving qualities of opium products Natural transmitters called endorphins Short for "Endogenous morphine" Morphine originating from within Endorphins and Opioid drugs bind to Opioid receptors (Named after opium) Opiate/Opioid drugs bind directly to opioid receptors Morphine, Codeine, Heroin, Methadone, Oxycontin, Percocet, Vicodin, Dilaudid
The ____ controls vital reflexes including breathing, heart rate, vomiting, salivation, coughing, and sneezing.
Medulla - Heart rate, BP, reparations Part of the hind brain (along with pons) Enlarged extension of spinal cord Controls vomiting, weak blood brain barrier so you can vomit quickly Cranial nerves allow the medulla to control sensations form the head, muscle movements in the head, and many parasympathetic outputs to the organs (12 or 13 cranial nerves)
Gordon is having trouble sleeping and decides to take a supplement containing a hormone that is manufactured in the pineal. What is he most likely taking?
Melatonin It is released in the evening and induces sleepiness. Gordon can take melatonin supplements that will have a similar effect to the endogenous hormone. Monoamine Manufactured directly from serotonin
Extra
Mesolimbic dopaminergic pathway Dopamine from VTA, travels to the nucleus accumbens, all the way to prefrontal cortex signals reward - drugs of abuse (taken for rewarding properties) Animals have the same reward system as humans (they self administer alcohol, cocaine, and THC) Each side receives sensory information and controls motor movement from the opposite (contralateral) side of the body Biological Psychology is the study of the physiological, evolutionary and developmental mechanisms of behavior and experience (assumes monoism) The action of a neurotransmitter can be excitatory or inhibitory, depending on the type of receptor - neurotransmitter will always be the same Left side of brain = facts and logic, right side = artistic/imagination
Monoism vs Dualism
Mind-Body problem: What is their relationship? Dualism: Mind and body are separate (Mind and body interact, but are separate from each other) Body is matter but mind is not The mind cannot be reduced to the workings of the nervous system or vice versa Most common belief among non scientists Rejected by most neuroscientists ; it infers that there is something that is unobservable- something that science can never look at or evaluate? Something that is completely random? Scientists don't like that Scientific defender of Dualism: Rene Desartes Body and soul joined at the pineal gland (Pineal gland operated by the soul) Movement of gland causes bodily movement by altering the flow of animal spirits in the nerves Well he was right about pineal gland having effect on emotions, but not by soul moving fluids around Monism: Everything in the universe consists of matter The mind is a phenomenon produced by the workings of the nervous system/ body Researchers In physiological psychology are usually monists Believe that studying the nervous system will eventually solve the mystery of the mind Fundamental randomness is the one thing scientific method can prove/speak to
Research using contemporary imaging methods have shown that people with a larger amygdala tend to have ____.
More social contacts
Multipolar, unipolar, and bipolar neurons
Multipolar: Has one axon and many dendrites attached to soma (most common) Bipolar (one axon and one dendrite)- usually sensory Unipolar: One axon attached to soma, the axon divides - one branch receives sensory info, the other sends it to the central nervous system
Myelin Sheath
Myelin Sheath: coating around axons, only appears in segments, little pieces with breaks in between =Node of ranvier = only place where axon channels are exposed/ ions can enter/exit) Encased part of axons cant have any gates because nothing could get in - maximizes the forces that are involved in movement (diffusion and electrostatic pressure) - If flow of ions separated by ideal amount of space= maximizing pressures Myelin sheath and NOR allow for fastest communication of single because of break in distance between channels (Myelin sheath speeds shit up) Shorter neurons don't have this, only needed for longer ones Allows action potential to travel more rapidly
The mesolimbic dopaminergic system signals reward by releasing dopamine from the ventral tegmental area (VTA) onto which structure
Nucleus accumbens
Primary visual cortex is located in the ____ lobe. a. frontal b. occipital c. parietal d. temporal
Occipital Occipital: Integrates visual input Located at the posterior end of the cortex Damage can result in cortical blindness
Oligodendrocytes
Oligodendrocytes wrap around the axon of neurons and produce myelin sheath Has projections that extend from the cell body that will wrap around the axon of a neuron, then appendage will break off, and piece that is wrapped around becomes myelin sheath - responsible for all myelin sheath - allows signal to go a little bit faster No myelin sheath- timing can be thrown off Myelin sheath comes from oligodendro cells
Dot is a cat with a huge brown spot on her dorsal side. The rest of her fur is white. Where is the spot located? a. on Dot's stomach b. on Dot's back c. toward Dot's front end d. toward Dot's rear end
On Dot's back
If damaged, axons in the _____ can grow back slowly if allowed to follow the original myelin sheath. However, axons in the _____ have a harder time growing back in part because the astrocytes produce a lot of scarring.
PNS/CNS If the myelin remains intact, cells in the PNS can possibly regrow (with the help of Schwann cell support). This is why you can cut your finger and still have feeling return once it has healed. This process is harder to do in the CNS due to the amount of scarring produced by the astrocytes.
The ____ system consists of the cranial nerves and nerves from the sacral spinal cord.
Parasympathetic - "rest and digest" system as it facilitates nonemergency states in the body. -craniosacral system as it is composed of all the cranial nerves and nerves from the sacral spinal cord. -Acetylcholine
Dr. Chiarella's lab studies the primary somatosensory cortex, located in the ____ lobe. a. frontal b. occipital c. parietal d. temporal
Parietal back top of brain - responsible for body sensations) Integration of sense Processes and integrates information about eye, head, and body positions from info form muscles and joints Postcentral gyrus: Primary somatosensory cortex which is the primary target for touch sensations, and information from muscle stretch receptors and joint receptors
Parkinson's disease and MPTP
Parkinson's disease, loss of dopamine, substantia nigra The 80% threshold MPTP (Substitute for opiate = synthetic opiate) and the case of the frozen addicts Ended up manufacturing MPP+, which enters dopamine cells through transporter mechanism, and as its metabolized, it destroyed neurons Individuals were paralyzed = drug destroyed dopaminergic neurons = caused advanced parkinson's rapidly = damaged substantia nigra- some did not recover Brain damage can occur without overt symptoms Mohammad Ali suffered from parkinsons Michael J. Fox too
Biological explanations of behavior fall into 4 categories
Physiological: Relates a behavior to the activity of the brain and other organs (Startle from Loud unexpected noise = Heart starts racing) -Explanation: as a result of auditory input, the sympathetic nervous system is releasing the neurotransmitter norepinephrine onto our heart Ontogenetic: Describes the development of a structure or behavior (learned behaviors) Evolutionary: Reconstructing evolutionary history of a behavior or structure Functional: Describes WHY a structure or behavior evolved as it did, what function does it serve in our environment Functional Explanations: Giraffes with long necks- more likely to survive to reproduce to pass on genes
Adenosine is an example of the ____ category of neurotransmitters.
Purine Purines: Adenosine, ATP
From DNA to Protein
RNA makes a mirror copy of DNA Transcription: Process of creating one stranded string Translation: RNA gets turned into protein RNA (messenger RNA) leaves nucleus and attaches to ribosomes Ribosomes translate the sequence into a sequence of amino acids Ribosomes made out of protein, basically everything is made out of protein 3 base pairs *codon)= 1 amino acid TAT= Tyrosine Amino acid chain folds into a protein (20 different amino acids) RNA: T replaced with U RNA is single sided and coding will include Uracil
___ guide the migration of neurons and their axons and dendrites during embryonic development.
Radial Glia Serve as structure to help neurons move across our brain - most neurons are stationary now, because you are an adult, but at one point they had to move out - travel along radial glia - we still birth small amount of new neurons
Karin just burned her finger on a hot pan. What is the circuit from sensory neuron to muscle response called that transmitted the message that she should remove her finger from the pan?
Reflex Arc When Karin touched the hot pan, a message was sent via her sensory nerves to the spinal cord. Within the spine, an interneuron quickly relayed the message to her motor neurons, which, in turn, resulted in her jerking her hand away from the hot surface.
Refractory Period
Refractory period: Period after an action potential, during which ht neuron resists firing another action potential Sodium channels are closed Absolute refractory period: Period in which the membrane can not produce an action potential Can start firing again after absolute pause Rate on which it fires depends on neuron before it Relative refractory period: It takes a stronger than usual stimulus to trigger an action potential Still can be active during this period if neuron is rapid firing Can be fired if you give it enough input
Twin Studies
Researchers study monozygotic (from one egg) and fraternal (from two eggs) twins to infer contribution of heredity and environment Identical = monozygotic =Shared placenta = identical DNA Fraternal = dizygotic = separate placenta = related DNA Concordance rate: Likelihood that if one twin has it, the other does too
Types of Neurons (shapes determine function)
Sensory neurons: Gather and conduct information from the environment Recieves info from senses Has its nucleus/soma detached from one giant axon (unipolar neuron- info going in one direction) Sensory endings instead of dendrites Motor Nerves: COntrol contraction of muscles Structured like multipolar neuron - range of dendrites that can receive info Communicates directly to muscle fibers (axon terminals) Interneurons: Lie entirely within the central nervous system- input comes from other neurons, output goes to other neurons Neurons in the brain that receives information from the outside world but it doesn't take info in directly or directly communicate with muscles- function is just to process in between - communicate with other interneurons, communicate with motor neuron/sensory neuron Interneurons or intrinsic neurons are those whose dendrites and axons are completely contained within the central NS
Many hallucinogenic drugs are chemically similar to ____.
Serotonin
Which of the monoamines is not a catecholamine:
Serotonin
Metatropic Receptor
Slow receptors: End effect on postsynaptic cell is much slower than opening channel immediately Act through 2nd messenger chemicals -Messenger proteins (g-proteins) travel through neuron and unsnap from receptor and diffuse through out the interior of the cell, causing a cascade of effects, then channel opens Some of the g proteins can find other receptors and bring them inside cell
Consider a wiring arrangement of neurons in which the two neurons (A and B) stimulate a third neuron (X). Neither neuron A nor B can stimulate neuron X on its own, but can excite neuron X in combination. This is an example of ____.
Spatial summation Synaptic inputs from separate locations combine their effects on a neuron. Sherrington demonstrated this by pinching two places at once (A and B) to stimulate X when neither A nor B alone was sufficient. One input may not be enough, but multiple neurons at same time, each giving one signal, could be enough to excite
Neurons
Specialized cells that receive, conduct and transmit electrochemical signals Estimated number in the human brain: 100 billion Most neurons (70 billion) in cerebellum (back of the head), 1 billion in spinal cord, rest in cerebral cortex
What term describes periodic production of action potentials, even without synaptic input?
Spontaneous firing The spontaneous firing rate refers to the periodic production of action potentials despite synaptic input EPSPs increase the number of action potentials above the spontaneous firing rate IPSPs decrease the number of action potentials below the spontaneous firing rate
Stimulant drugs, including amphetamine and cocaine, decrease reuptake and prolong the effects of various neurotransmitters. Which of the following is not one of those neurotransmitters?
Stimulant drugs, including amphetamine and cocaine, decrease reuptake and prolong the effects of serotonin, norepinephrine, and dopamine by inhibiting the transporters. GABA
Limbic System
Structures that form a border around the brainstem Olfactory bulb, hypothalamus, hippocampus (memory), amygdala (emotion), and cingulate gyrus of the cerebral cortex MAINLY HYPOTHALAMUS, AMYGDALA, AND HIPPOCAMPUS Motivation, emotion, memory, drives and aggression
Charles Scott Sherrington
Studied reflexes of animals Demonstrated that nerves communicate information from the senses to the muscles 1906: coined the term synapse to describe the specialized gap that existed between neurons Conducted research investigating how neurons communicate with each other by studying reflexes (automatic muscle responses to stimuli) Sherrington observed 3 important points about reflexes: Reflexes are slower than conduction along an axon (hypothesized that delay was caused by communication between two neurons (sensory and intrinsic, and intrinsic and motor)) Difference in the speed of conduction in a reflex arc from previously measured speed of nerve conduction As one set of muscles relax, another set becomes excited (two different types of communication: Stop and go) -Temporal summation (one neuron firing a lot) Sherignton also noticed that several small stimuli on a similar location produced a reflex when a single stimuli did not - spatial summation, or that synaptic input from several locations can have a cumulative effect and trigger a nerve impulse Spatial Summation: Input from multiple neurons firing simultaneously can reach the threshold of excitation Sherrington also noticed that during the reflex that occurs, the foot of a dog that was pinched retracted while the other 3 feet were extended He suggested that an interneuron in the spinal cord sent an excitatory message to the flexor muscle of one leg and an inhibitory message was sent to the other 3 legs This led to the idea of inhibitory postsynaptic potential or the temporary hyperpolarization of a membrane
In which areas of the brain is dopamine produced?
Substantia Nigra (dopamine to motor systems) and Ventral Tegmental Area (providing dopamine to nucleus accumbent to signal reward) Dopamine then gets sent to basil ganglia
The ____ is a part of the brain that is very important for vision.
Superior Colliculus Part of the midbrain The swellings on each side of the tectum are the superior colliculus and inferior colliculus. Both are important for sensory information: the inferior colliculus for hearing and the superior colliculus for vision. Midbrain: Coordinates movement with sensory input Also includes Substantia nigra, tectum, tegmentum
Synapse
Synapse: Junction between the terminal button of an axon and the membrane of another neuron Presynaptic and postsynaptic neuron/membrane POSTSYNAPTIC MEMBRANE becomes thicker as a result of communication, = postsynaptic density Chemicals stored in vesicles: receives signal from axon, vesicles move towards presynaptic membrane, fuse with it, Presynaptic Membrane: The membrane of a terminal button, through which neurotransmitter is released. Postsynaptic membrane: Cell membrane on the opposite side of a terminal button in a synapse Synaptic cleft: The space between the presynaptic membrane and the postsynaptic membrane. Contains extracellular fluid Synaptic vesicle: Small bead like structure found in terminal buttons - contains neurotransmitter (Chemical that are released by the terminal button) Postsynaptic density: Region in the postsynaptic membrane that is under the terminal button- contains receptors Possible effects of neurotransmitters on the postsynaptic membrane: Excitatory Postsynaptic potential (EPSP): "Excites" the postsynaptic membrane Inhibitory postsynaptic potential (IPSP): "inhibits" the post- pynaptic membrane - more hyperpolarized in receiving area
The ____ lobe contributes to complex aspects of vision, including perception of movement and recognition of faces.
Temporal The temporal lobe is responsible for a variety of different functions, including understanding/processing spoken language (left temporal lobe), hearing (auditory information), and various aspects of advanced visual processing Temporal lobe important for speech (speech on left side of brain) Located in bottom middle Recognition of sights and sounds and long-term memory storage Part of cerebral cortex Complex aspects of vision including movement and some emotional and motivational behaviors
What term is used for the cumulative effect of repeated stimulation over a brief period of time? a. excitatory postsynaptic potential b. spatial summation c. temporal summation d. inhibitory postsynaptic potential
Temporal Summation Charles Sherrington observed that repeated stimuli over a short period of time produced a stronger response Led to the idea of temporal summation or that repeated stimuli can have a cumulative effect and can produce a nerve impulse when a single stimulus is too weak Temporal Summation: Neuron A (presynaptic neuron) sends an excitatory signal (by releasing transmitter) repeatedly over a short amount of time Neuron B (Postsynaptic neuron) becomes progressively more excited (positive charge) until the threshold of excitation is reached
Forebrain
Thalamus, hypothalamus Cerebral cortex, hippocampus, basal ganglia Telencephalon Diencephalon Location of most sensory, emotional,and cognitive processing Two specialized hemispheres (left and right) joined by the corpus callosum Thalamus: Relay station from the sensory organs to the cortex- structure that provides most of the direct input to the cerebral cortex
All or none law
Threshold of excitation: If input is not sufficient to raise above -60, then neuron will not fire Neurons either fire or they don't, no intermediate pulse All action potentials are of equal intensity (amplitude). As such, a neuron can only send "on" or "off" signals However, more intense stimuli produces more RAPID firing More rapid = stronger signal Applies to axons Aspects of information are communicated by rate of firing
The major sequence of events allowing communication between neurons across the synapse:
The neuron synthesizes chemicals that serve as neurotransmitters Neurons store neurotransmitters in axon terminals or transport them there An action potential triggers the release of neurotransmitters into the synaptic cleft The neurotransmitters travel across the cleft and attach to receptors on the postsynaptic neuron The neurotransmitters separate from the receptors The neurotransmitters are taken back into the presynaptic neuron, diffuse away or are inactivated by chemicals The post synaptic cell may send negative feedback to slow the release of further neurotransmitters Most individual neurons release at least two or more different kinds of neurotransmitters Neurons may also respond to more types of neurotransmitters than they release
Axons
Thin fiber of neuron responsible for transmitting nerve impulses toward other neurons, organs, or muscles Axon hillock: Area in which axon emerges - where voltage gated ion channels are that initiate action potential to travel down axon
Monoamines
Three major monoamines: Dopamine, norepinephrine,and serotonin Dopamine (DA) Tyrosine -> L-Dopa -> Dopamine Norepinephrine (NE, Noradrenaline) Dopamine -> norepinephrine Serotonin (5-HT) Tryptamine -> serotonin Histamine Low levels of (one or all, depends on individual) dopamine, serontonic, adn NE are associated with depression
Frederick is interested in using his diet to elevate his mood. His doctor suggested that he try to increase the amount of ____ in his diet, because it controls the amount of serotonin in the brain.
Tryptophan Tryptophan serves as a precursor for serotonin/leads to serotonin Example of amino acid from diet
Terms used to describe location when referring to the nervous system
Ventral: Toward the stomach Dorsal: toward the back (Toward the back portion of our spine) Anterior: Toward the front end (towards brain end of neuraxis) Posterior: Toward the back end Lateral : Toward the side Medial: toward the midline Kinda confusing because human axis takes a sharp right turn......
Which of the following is not a monoamine:
acetylcholine Smaller neurotransmitters are synthesized in the presynaptic terminal and held there for release Example: acetylcholine Acetylcholine (ach): Implicated in memory Nicotine activates "Nicotinic" acetylcholine receptors Alzheimer's disease characterized by Ach deficits Acetylcholine is released from motor neurons: First discovered
Aimee is trying to memorize the anatomical directions for her physiology quiz so she is associating her body parts with the various terms. Which of the following should she remember to be ventrally located?` a. Her stomach and the tip of her nose b. Her chest and the top of her head c. Her stomach and the underside of her chin d. Her back and the back of her head
c. Her stomach and the underside of her chin The anatomical directions were first described in four-legged creatures. Because humans walk on two legs and hold the head differently, the directions can be a bit confusing, especially when comparing the head to the body. In this case, Aimee's stomach and underside of her chin are both ventrally located. Dorsal: Toward the back, away from the ventral (stomach) side. The top of the brain is considered dorsal because it has that position in four legged animals Ventral: Toward the stomach, away from the dorsal (back) side
Cathecholamines
contain a catechol group and an amine group (Epinephrine, norepinephrine, and dopamine) Catecholamines = catechol base Catecholamine Synthesis Dopamine synthesis depends on the enzyme tyrosine hydroxylase How much dopamine you produce depends on how much "TH" is present This "TH" is the RATE LIMITING FACTOR in dopamine production
The temporary hyperpolarization of a membrane is a(n) ____. a. excitatory postsynaptic potential b. spatial summation c. temporal summation d. inhibitory postsynaptic potential
inhibitory postsynaptic potential The resting membrane potential of a neuron is around -70mV. When a cell is hyperpolarized (made more negative), it is said to be slightly inhibited, as it would now take an even stronger positive stimulus to reach threshold. Once the charge has become strong enough, voltage gated ion channels open causing the charge to rapidly shift positive Once it hits positive territory, different set of gates open at like +20 so that it drops into hyperpolarization (-70- -80) Synaptic communication which causes the membrane potential to be more positively (less negatively) charged is an : An excitatory postsynaptic potential (EPSP) Inhibitory postsynaptic potential letting more negatively charged ion into cell/allowing positively charged ions to exit cell When an EPSP is triggered, Na+ moves: Into the neuron/ion Hyperpolarization: Increase in the membrane potential Membrane becomes more polarized than at rest
Prefrontal cortex (frontal lobe)
the integration center for all sensory information and other areas of the cortex Decision making/executive functioning Phineas gage Responsible for higher functions such as abstract thinking and planning Responsible for your ability to remember recent events and information (working memory) Allows for regulation of impulsive behavior and the control of more complex behaviors
