Final Biopsychology Exam UT Dominguez

The _________ is important for learning about rewards and punishments

*Prefrontal cortex*: faster and based more on recent events *Basal Ganglia*: slower based on the average reward over long period of time

cholecystokinin (CCK)

A hormone released in the duodenum. CCK limits meal size by closing the sphincter muscle between the stomach and the duodenum, causing the stomach to hold its contents and fill more quickly than usual. CCK also stimulates the vagus nerve, which sends a message to the hypothalamus, causing cells there to release a neurotransmitter that is a shorter version of the CCK molecule itself

Equipotentiality

All parts of the cortex contribute equally to complex behaviors such as learning, and any part of the cortex can substitute for any other. This is not entirely correct.

SSRIs

Blocks the reuptake of serotonin. SSRIs produce milder side effects than tricyclics, but equal effectiveness -Prozac/Fluoxetine -Sertraline/Zoloft -fluvoxamine/Luvox -Citalopram/Celexa -Paxil/Seroxat

Anterior and Inferior Temporal Lobe Damage and Memory

Causes *semantic dementia* which is the loss of semantic memory. Portion of long-term memory that processes ideas and concepts that are not drawn from personal experience (like letters, capitals, colors, facts)

Chronic

Gradual onset, lower chance of recovery

Implicit memory

Influence of recent experience on behavior, even if one does not recognize that influence

Hunger Sensitive Neurons

Influenced by the neyurotransmitter *ghrelin* and from taste pathways Input from the hunger-sensitive neurons of the arcuate nucleus is inhibitory to both the paraventricular nucleus and the satiety-sensitive cells of the arcuate nucleus itself. Sends combination of GABA (main inhibitory transmitter) and *NPY* and *AgRP* which block the satiety actions of the PVN Another pathways leads to lateral hypothalamus to release *orexin/hypocretin*

Insulin

Insulin regulates the flow of glucose into the blood; enables glucose to enter the cells, except for brain cells, where glucose does not need insulin to enter. When insulin levels are high, cells receive glucose easily. When someone is getting ready for a meal, insulin levels rise, letting some of the blood glucose enter the cells in preparation for the rush of additional glucose about to enter the blood. Insulin increases even more during and after a meal. High levels of insulin tend to decrease appetite

lactase

Intestinal enzyme which is necessary for metabolizing *lactose* which is the sugar in milk. In most mammals at about the age of weaning this intestinal enzyme is lost. Declining levels of lactase help encourage weaning

AMPA receptor

Ionotropic receptor that is ordinarily excited by glutamate, but it can also respond to a drug called AMPA. The AMPA receptor is a typical ionotropic receptor that opens sodium channels.

Lateral Interpositus Nucleus

Thompson identified one nucleus of the cerebellum, the lateral interpositus nucleus (LIP), as essential for learning. At the start of training, those cells showed little response to the tone, but as learning proceeded, their responses increased. When LIP was suppressed, the training had no effect. It is necessary both for learning and for retention and for the extinction of learned responses

Lithium

Treatment for bipolar disorder. Lithium stabilizes mood, preventing a relapse into either mania or depression. The dose must be regulated carefully, as a low dose is ineffective and a high dose is toxic. Bipolar meds generally decrease the number of AMPA type glutamate receptors in the hippocampus. Excessive glutamate activity is responsible for some aspects of mania. Also blocks synthesis of arachidonic acid which is produced during brain inflammation

Within the _________________, some cells respond when the reward is more than expected, and others when it is less than expected

anterior cingulate cortex

Reinforcer

any event that increases the future probability of the response.

Working Memory

emphasize that temporary storage is not a station on the route to long-term memory but the way we store information while we are working with it; the part of short-term memory that is concerned with immediate conscious perceptual and linguistic processing.

Operant Conditioning

individual's response leads to a *reinforcer* or *punishment*

Cells in the _____________ respond based on how that reward compares to other possible choices

orbitofrontal cortex

Red Nucleus

suppressing the red nucleus temporarily prevented the response but did not prevent learning. That is, learning did not depend on the red nucleus or any area after it.

Mass Action

the cortex works as a whole, and more cortex is better. This is not entirely correct.

Arcuate nucleus

"Master area" for appetite control in the hypothalamus. Axons extend to other areas in the hypothalamus. Has one set of neurons receptive to hunger signals (receive input from taste cells and from axons releasing neurotransmitter *ghrelin*), and one to satiety signals (includes distension of intestines triggering CCK, blood glucose levels stimulate directly causing secretion of insulin, and leptin). Sends output to paraventricular nucleus of the hypothalamus (PVN) which inhibits the *lateral hypothalamus*. Axons from satiety-sensitive cells send excitatory message to PVN causing rlease of *melanocortin* which helps limit food intake

High or Low Insulin levels

*Constantly High Levels*: hunger will remain because blood is sending out so much glucose constantly that glucose levels drop. Animals that hibernate have constantly high insulin levels in the fall for this reason by rapidly depositing meals into flat and glycogen and gaining weight. *Constantly Low Levels*: people with diabetes, blood glucose levels may be three or more times the normal level, but little of it enters the cells. Causes people to eat more food than normal because their cells are starving but they excrete most of their glucose and lose weight. Both cause excess eating, but have different effects on weight gain.

conditioned taste aversion

*conditioned taste aversion* develops when you try something new and then become ill, so your brain blames the illness on the food and it won't taste good to you the next time

MAOIs

-Block the enzyme monoamine oxidase (MAO) which metabolizes catecholamines and serotonin in presynaptic cell -MAOIs block this enzyme, so the presynaptic terminal has more of its transmitter available for release -Generally a back up for people where SSRIs or Tricyclics failed If taking MAOIs, you must avoid foods with tyramine which cause an incresase in blood pressure.

The hippocampus is important for (3 theories)

-Declarative memory -Spatial Memory -Context

How to learn what is edible?

-Experience of others; juveniles imitate food selection of elders -children acquire culture's food preferences, especially for spicy foods -select sweet foods + avoid bitter ones, eat salty or sour foods in moderation→sweet foods tend to be nutritious while bitter tend to be toxic -the familiarity of taste is important because it shows that a food is probably safe -*conditioned taste aversion* develops when you try something new and then become ill, so your brain blames the illness on the food and it won't taste good to you the next time

Mechanisms by which LTP occurs (4 and summary)

-The dendrite builds more AMPA receptors or moves old ones into better positions - In some cases, the neuron makes more NMDA receptors -The dendrite may make more branches, thus forming additional synapses with the same axon; that enriched experience also leads to increased dendritic branching. -Possibly, some individual AMPA receptors become more responsive than before. When glutamate massively stimulates AMPA receptors, the resulting depolarization enables glutamate to stimulate nearby NMDA receptors also. Stimulation of the NMDA receptors lets calcium enter the cell, where it sets into motion a series of changes that potentiate the dendrite's future responsiveness to glutamate at AMPA receptors. After LTP occurs, NMDA receptors revert to their original condition.

There is a strong relationship between happy mood and increased activity in the ___1______. Most people with depression have decreased activity in the ____2______and increased activity in the _____3_______.

1. Left prefrontal cortex 2.Left prefrontal cortex 3 Right prefrontal cortex

Hebbian Synapse

A synapse that increases in effectiveness because of simultaneous activity in the presynaptic and postsynaptic neurons is called a Hebbian synapse. So an axon that has successfully stimulated cell B in the past becomes even more successful in the future

Postpartum Depression

About 20% of women report some degree of postpartum depression. Most women recover quickly without treatment, but about 0.1% enter a serious, long-lasting depression. Postpartum depression is more common among women who have also suffered major depression at other time some women are more vulnerable to depression than others, and hormonal changes can trigger an episode of depression for the vulnerable women.

Alzheimer's Disease

Alzheimer's patients have better procedural than declarative memory Memory and alertness vary day to day suggesting that many of their problems result from malfunctioning neurons Gradually progresses to more serious memory loss, confusion, depression, restlessness, hallucinations, delusions, sleeplessness, and loss of appetite

Sensitization

An increase in response to mild stimuli as a result of exposure to more intense stimuli.

sham-feeding

Animals eat and swallow but food doesn't enter stomach so they remain unsatiated. Important because humans desire chewing and tasting but it's not enough to do that to feel full.

Path in digestive system

Begins in mouth with mastication and saliva →esophagus →stomach (HCL and enzymes to break down proteins) →sphincter opens →small intestine (enzymes digest proteins, fats and carbs and absorb into bloodstream) →blood caries chemicals to body cells for use or storage →large intestine absorbs water and minerals →out the end

Tricyclics

Block the transporter proteins that reabsorb serotonin, dopamine, and norepinephrine into the presynaptic neuron after their release→ prolong the presence of the neurotransmitters in the synaptic cleft People have to limit their use of tricyclics because: -Blocks histamine receptors→drowsiness -Blocks acetycholine receptors→dry mouth and trouble peeing -Blocks sodium channels→heart irregularities

leptin

Body's fat cells produce leptin: the more fat cells, the more leptin, which signals the brain about the body's fat reserves, providing a long-term indicator of whether meals have been too large or too small. When leptin levels are high, animals act as if they have plenty of nutrition. They eat less and become more active and increase activity in the immune system Excess leptin can increase the risk of diabetes Note: low levels of leptin increase hunger, but high levels do not necessarily decrease it. For the vast majority of obese people, who already have high leptin levels, giving them still more is seldom effective (perhaps due to lowered sensitivity to leptin)

Bullima nervosa

Bulimia nervosa is a condition in which people alternate between extreme dieting and binges of overeating. About 95% of people with bulimia also have at least one other psychiatric disorder, such as depression or anxiety. People with bulimia have decreased release of CCK, increased release of ghrelin, and alterations of several other hormones and transmitters associated with feeding. A cycle of food deprivation followed by overeating strongly stimulates the brain's reinforcement areas

Acute

Condition with sudden onset (better in the case of schizophrenia with higher chance of recovery)

Consolidate

Consolidating a long-term memory depends on more than the passage of time; emotionally stirring memories consolidate quickly. Stressful or emotionally exciting experiences increase the secretion of epinephrine (adrenaline) and cortisol. Small to moderate amounts of cortisol activate the amygdala and hippocampus, where they enhance the storage and consolidation of recent experiences. The amygdala in turn stimulates the hippocampus and cerebral cortex, which are both important for memory storage.

splanchnic nerves

Convey information about the nutrient contents of the stomach

vagus nerve

Conveys information about the stretching of the stomach walls, providing a major basis for satiety.

Explicit memory

Deliberate recall of information (like test questions)

SAD

Depression that recurs during a particular season, such as winter, is most prevalent near the poles Patients with SAD have phase-delayed sleep and temperature rhythms—becoming sleepy and wakeful a bit later than normal Can be treated with an hour of bright light every day

Electroconvulsive Therapy (ETC)

ECT is quick and most patients awaken without remembering it, and usually works faster than antidepressants with improvements in as little as a week. Increases neuron proliferation in hipocampus and effects genes related to neurotrophins, arachidonic acid, etc. It is applied every other day for 2 weeks, and patients are given muscle relaxants to minimize discomfort. The most common side effect is memory loss, but when only applied to right hemisphere this is avoided. The issue is relapse into more depression after a couple months, so to prevent this, it's important to partner with drugs, psycotherapy or periodic ETC

omnivore

Eats meat and plants; has to distinguish between edible and inedible substances and find enough vitamins and minerals

Parietal Lobe Damage and Memory

Episodic memory is intact, but can't elaborate on a memory spontaneously.

Atypical Antidepressants

Everything that's not an SSRI, Tricyclic, or MAOI Ex. Buproprion which inhibits dopamine reuptake and to some extend norepinephrine uptake

Retrograde Transmitter

Extensive stimulation of a postsynaptic cell causes it to release a retrograde transmitter that travels back to the presynaptic cell to modify it (often NO). As a result, a presynaptic neuron decreases its threshold for producing action potentials, increases its release of neurotransmitter, expands its axon, and releases its transmitter from additional sites along its axon

Major Depression

Feeling sad and helpless every day for weeks at a time. They have little energy, feel worthless, contemplate suicide, have trouble sleeping, cannot concentrate, find little pleasure, and can hardly even imagine being happy again. 2x women than men Moderate heritability but no specific gene One gene controls the serotonin transporter protein, which regulates the ability of an axon to reabsorb serotonin after its release, to recycle it for further use; the short form of the gene by itself does not lead to depression, nor does a series of stressful events, but a combination of both is hazardous

Glucagon

Glucagon stimulates the liver to convert some of its stored glycogen to glucose to replenish low supplies in the blood

Habituation

Habituation is a decrease in response to a stimulus that is presented repeatedly and accompanied by no change in other stimuli. The sensory neuron still gives a full, normal response to stimulation; it merely fails to excite the motor neuron as much as before

Areas to Memory Types (3)

Hippocampus-storing certain kinds of memory, episodic, declarative, spatial Basal Ganglia-important for procedural memory Prefrontal Cortex-important for working memory and reasoning

Humans and milk

Humans are the exception to the rule about adult mammals not drinking milk: most people have enough lactase levels to consume dairy throughout life. But Asians generally don't have the gene for adults to metabolize lactose. Gene for lactose digestion is different in Africa and Europe so evolved distinctly in response to domestication of cattle.

Amygdala

Important for fear learning

Orexin

In lateral hypothalamus, released from influence of hunger cells; a lack of this causes narcolepsy. Orexin increases persistence in seeking food after periods of food deprivation and responds to incentive or reward properties of a meal i.e. orexin receptors in your hypothalamus can override other satiety signals to allow you to dig into food you want to eat even when you're not actually hungry.

Obesity

In some cases, obesity can be traced to the effects of a single gene. The most common of these is a mutated gene for the receptor to *melanocortin* causing obesity from childhood onward People with a variant form of one gene called FTO weigh 3 kg (6-7 lb) more than other people, on the average and have higher risk of obesity *Prader-Willi syndrome* is a genetic condition marked by mental retardation, short stature, and obesity. People with this syndrome have blood levels of ghrelin (the hunger deprivation hormone) four to five times higher than average *syndrome obesity* results from a medical condition.

Anterograde amnesia

Inability to form memories for events occurring after the brain damage

Retrograde amnesia

Inability to remember events from before the damage; usually worse for first few years before the damage and improves the further back you go

NMDA receptor

Ionotropic receptor that is ordinarily excited only by glutamate, but it can respond to a drug called NMDA. Its response to the transmitter glutamate depends on the degree of polarization across the membrane. The NMDA channel opens only if magnesium leaves, and the surest way to detach the magnesium is to depolarize the membrane. When calcium enters through the NMDA channel, it activates a protein called CaMKII (needed for LFT). Once LTP has been established, it no longer depends on NMDA synapses. Drugs that block NMDA synapses prevent the establishment of LTP, but they do not interfere with the maintenance of LTP that was already established

Engram

Karl Lashley searches for the *engram* which is the physical representation of what had been learned in the brain with a connection between cells

ventromedial hypothalamus (VMH)

Lesions in VMH cause intense weight gain though it eventually levels out; to create this effect damage must extend to invade nearby axons. Damaged VMH causes rats to eat normal sized meals, but more frequently because they have increased stomach motility and secretions, and their stomachs empty faster than normal. Also causes increase in insulin production so each meal is stored as fat

duodenum

Meals end after distension of either the stomach or the duodenum; part of the small intestine adjoining the stomach. It is the first digestive site that absorbs a signifi cant amount of nutrients. Food in the duodenum releases the hormone

carnivore

Meat eater.

Melanocortin

Melanocortin receptors in the paraventricular nucleus are important for limiting food intake, and deficiencies of this receptor lead to overeating

Episodic memories

Memories of single events; amnesia regarding episodic memories can potentially be explained by the theory that the hippocampus is important for remembering the context for when learning occured

Amnesia

Memory loss; can be caused by lesion or ablation of hippocampus and the medial temporal lobe. Generally patients with amnesia can have functioning short term or working memory. Generally have: -Normal short-term or working memory - Severe anterograde amnesia for declarative memory—that is, difficulty forming new declarative memories - In many cases, a severe loss of episodic memories - Better implicit than explicit memory -less impaired procedural memory

Long term memory

Memory of events further back; larger capacity, and sticks with you longer; a hint might help you reconstruct something you thought you had forgotten

Short-Term Memory

Memory of events that just occurred. Has a much smaller capacity (7 number) and fades quickly unless you rehearse information; once you have forgotten something, it is lost

How do antidepressants work?

Neurons in parts of the hippocampus and cerebral cortex shrink in some people with depression. Drugs increase the release of neurotransmitters, so the axons release a neurotrophin called brain-derived neurotrophic factor (*BDNF*) BDNF is especially important for synaptic plasticity and improves learning and increase the proliferation of new neurons in the hippocampus.

Ghrelin

Neurotransmitter released by axons that provide input to hunger-sensitive cells; it binds to same receptors as growth-hormone Released by the stomach during periods of food deprivation and acts on hypothalamus to decrease appetite and on the hippocampus to enhance learning

Long term Potentiation (3 properties)

One or more axons connected to a dendrite bombard it with a brief but rapid series of stimuli—such as 100 per second for 1 to 4 seconds. The burst of intense stimulation leaves some of the synapses potentiated (more responsive to new input of the same type) for minutes, days, or weeks. LTP is necessary for long-term learning and memory *specificity*: If some of the synapses on a cell have been highly active and others have not, only the active ones become strengthened (though stim at one synapse does briefly facilitate the formation of LTP at nearby synapses) *cooperativity:*Nearly simultaneous stimulation by two or more axons produces LTP much more strongly than does repeated stimulation by just one axon. *associativity:* Pairing a weak input with a strong input enhances later response to the weak input. In this regard, LTP matches what we would expect of Hebbian synapses. Mostly depends on changes at glutamate synapse

Lateral Hypothalamus

Output from the paraventricular nucleus acts on the lateral hypothalamus which controls *insulin* secretion and alters taste responsiveness and helps fascilitate feeding Damage to this area causes animals to refuse food and water. Can gradually recover ability to eat but first must be force fed. Damage to lateral hypothalamus interrupts dopamine passing fibers as well - Axons from the LH extend to the NTS alter the taste sensation and the salivation response to the tastes (makes food taste better when you're hungry) -Axons extend into parts of the cerebral cortex, facilitating ingestion and swallowing and causing cortical cells to increase their response to the taste, smell, or sight of food -Increases the pituitary gland's secretion of hormones that increase insulin secretion -Sends axons to spinal cord to control autonomic responses like digestive secretion

Classical Conditioning

Pairing two stimuli changes the response to one of Starts with *conditioned stimulus* which initially elicits no response, and presents the *unconditioned stimulus* which automatically elicits the *unconditioned response*. After pairing repeatedly, individual develops a *conditioned response* to conditioned stimulus.

Confabulation

Patients with Korsakoff's Syndrome guess to fill in memory gap. They confabulate only on questions for which they would expect to know the answer. For example, to a nonsense question like "Who is Princess Lolita?" they reply, "I don't know." They confabulate mainly on questions about themselves, their family, and other familiar topics

Pavlov Dogs

Pavlov presented a dog with a sound (CS) followed by meat (UCS), which stimulated the dog to salivate (UCR). After many such pairings, the sound alone (CS) stimulated the dog to salivate (CR).

Bipolar I disorder

People who have full-blown episodes of mania are said to have bipolar I disorder

Causes of Alzheimers (3)

People with Down syndrome almost invariably get Alzheimer's disease if they survive into middle age. 3 copies of chromosome 21 caused examination of chromosome where they found a gene linked to many cases of early onset Alzheimer's disease though there are other genes on other chromosomes as well. The genes controlling early onset Alzheimer's disease cause a protein called *amyloid-B or B-amyloid* to accumulate both inside and outside neurons which can damage axons and dendrites and cluster into structures called plaques which cause the cerebral cortex, hippocampus, and other areas to atrophy. Alzheimer's patients also accumulate an abnormal form of the *tau protein* that is part of the intracellular support structure of neurons which produce "tangles", structures formed from degenerating structures within neuronal cell bodies

Anorexia Nervosa

People with anorexia nervosa are unwilling to eat as much as they need. Th ey become extremely thin and in some cases die. About 0.9% of women and 0.3% of men in the United States develop anorexia nervosa.

Bipolar Disorder

People with bipolar disorder—formerly known as manic-depressive disorder—alternate between two poles—depression and its opposite, mania. In addition to the mood swings, most people with bipolar disorder have attention deficits, poor impulse control, and impairments of verbal memory There is a strong genetic component

herbivore

Plant eater; has to distinguish between edible and inedible substances and find enough vitamins and minerals

Stomach Distension

Sufficient to induce feeling of satiety. The stomach conveys satiety messages to the brain via the *vagus nerve* and the *splanchnic nerves*. But people with no stomachs still report satiety so distension isn't the only factor.

lactose

Sugar in milk which infants can digest using *lactase*; becomes difficult to digest later on when lactase is gone and causes cramps and gas Adult mammals don't drink much milk

How to decrease weight

The most successful treatments require a change of lifestyle, including increased exercise as well as decreased eating. That combination does help people lose weight, although at best only 20%-40% keep the weight off for at least 2 years. Reduce or eliminate soft drinks which are sweetened with fructose which doesn't increase insulin or leptin as much as other sugars, so you gain calories without feeling satiety. Diet drinks are also bad because they actually increase weight gain; you unlearn calibration that more sweets mean more energy so you overeat sweet other foods. *fen-phen*: The fen-phen combination produces brain effects similar to those of a completed meal but had medical complications *sibutramime (meridia)*: decreases meal size and binge eating *Orlistat (Xenical):* prevents the intestines from absorbing up to 30% of fats in the diet. Approximately half of people using orlistat have at least 5% weight loss 2 years later but creased intestinal discomfort from undigested fat *gastric bypass:* By decreasing stomach size, the surgery makes it possible for a smaller meal to produce satiety, but 10%-20% of people experience serious side effects, including infections, bowel obstruction, leakage of food, and nutritional deficiencies

Unipolar Depression

Vary between normality and one pole—depression

Long-term depression (LTD)

a prolonged decrease in response at a synapse, occurs when axons have been less active than others. You can think of this as a compensatory process. Associated with dendrite shrinkage and decreased synaptic receptors

Morris water maze task

a rat must swim through murky water to find a rest platform that is just under the surface A rat with hippocampal damage slowly learns to find the platform if it always starts from the same place and the rest platform is always in the same place. However, if it has to start from a different location or if the rest platform occasionally moves from one location to another, the rat is disoriented If a rat has already learned to find the platform before damage to the hippocampus, he won't even remember that there is a platform

Delayed non-matching to sample task

an animal sees an object (the sample) and then, after a delay, gets a choice between two objects, and must choose the object that is different from the sample animal must remember which object was present on this occasion, thereby showing what we might call a declarative memory, perhaps an episodic memory. Hippocampal damage strongly impairs performance

Delayed Matching-to-sample task

an animal sees an object (the sample) and then, after a delay, gets a choice between two objects, from which it must choose the one that matches the sample animal must remember which object was present on this occasion, thereby showing what we might call a declarative memory, perhaps an episodic memory. Hippocampal damage strongly impairs performance

Punishment

an event that suppresses the frequency of the response.

Korsakoff's Syndrome

brain damage caused by prolonged thiamine deficiency; most common in chronic alcoholics. Symptoms are apathy, confusion, and memory loss and *confabulation* in which patients guess to fill in memory gap Prolonged thiamine deficiency leads to a loss or shrinkage of neurons throughout the brain, and one of the areas most aff ected is the dorsomedial thalamus, which is the main source of input to the prefrontal cortex Are better at remembering things through rote repetition.

Depression in older men is linked to _____.

declining levels of testosterone

The hippocampus may be particularly important for remembering the ____________ of an event

details and context

Schizophrenia

deteriorating ability to function in everyday life and by some combination of hallucinations, delusions, thought disorder, movement disorder, and inappropriate emotional expressions memory impairment could be a central symptom -about 1% of the population has schizophrenia -diet high in sugar and saturated fat aggravates schizophrenia -more common in men than women, and more severe in men with early onset as their brains produce more dopamine

The _________ is important for spatial memory

hippocampus there is actual growth of the adult human hippocampus in response to spatial learning experiences (taxi cab experiment)

Radial maze

maze has eight or more arms, some of which have a bit of food or other reinforcer at the end. A rat placed in the center can find food by exploring each arm once and only once. Rats with damage to the hippocampus seldom enter the never-correct arms, but they often enter a correct arm twice. That is, they forget which arms they have already tried

Bipolar II disorder

milder manic phases, called hypomania, which are characterized mostly by agitation or anxiety.

Basal ganglia

more important for procedural memory, though most tasks tap both kinds of memory, and it is possible to shift from one type of memory to the other, even on the same task.

delayed response task

requires responding to something that you saw or heard a short while ago, used to demonstrate working memory

Declarative Memory

the ability to state a memory in words; the hippocampus is more important for this kind of memory

Procedural Memory

the development of motor skills and habits