Psyc 362- Exam 3

Homeostatisis

"Change in the face of change so as to remain unchanged..." Process by which body's substances and characteristics (temp and glucose level) are maintained at their optimal level Assumes regulatory mechanisms

Prognosis of Schizo

40% mild/moderate symptoms 25% mild/moderate remission 10% suicide 25% severe/chronic symptoms

5-TG

5-thioglucose Infusions into fourth ventricle block glucose metabolism and induce eating by causing glucoprivation

Sensory Memory

A brief period of time (ranging from fractions of a second to a few seconds) that the initial sensation of environmental stimuli is initially remembered. Sensory memory occurs in each of the senses and allows an individual to retain the experience of the sensation slightly longer than the original stimulus. Sensory memory is often experienced as a brief period in which sensory experiences can be remembered as repeating or "echoing."

Morris water maze

A common test of spatial memory. A rodent is placed in a small round pool filled with opaque-colored water and must remember the location of a submerged platform to escape. Damaged Hippocampus- learning is disrupted

Schizophrenia

A disorder of thought and emotion, but not a "split-personality" -Thought disorder -Hallucinations -Delusions -Bizarre behaviors Incidence is about 1% -No gender differences in incidence

Fasting phase

A fall in blood glucose level causes the pancreas to stop secreting insulin and to start secreting glucagon. The absence of insulin means that most of the cells of the body can no longer use glucose.--> As a result, all the glucose present in the blood is reserved for the CNS. The presence of glucagon and the absence of insulin instruct the liver to start drawing on the short-term carbohydrate reservoir—to start converting its glycogen into glucose. --> The presence of glucagon and the absence of insulin, along with increased activity of the sympathetic nervous system, also instruct fat cells to start drawing on the long-term fat reservoir—to start breaking down triglycerides into fatty acids and glycerol. --> Most of the body lives on the fatty acids, while the glycerol, which is converted into glucose by the liver, gets used by the brain.

medial forebrain bundle (MFB)

A fiber bundle that runs in a rostral-caudal direction through the basal forebrain and lateral hypothalamus; electrical stimulation of these axons is reinforcing

hippocampal formation

A forebrain structure of the temporal lobe, constituting an important part of the limbic system Without the hippocampal formation we would be left with individual, isolated memories without the linkage that makes it possible to remember—and think about—episodes and contexts. DAMAGE TO HIPPOCAMPAL FORMATION CAUSES ANTEROGRADE AMNESIA

Insulin

A hormone produced by the pancreas or taken as a medication by many diabetics Promotes utilization and storage of nutrients Increases the conversion of glucose to glycogen in liver and muscles Permits entry of glucose into all cells (except for neurons) Increases conversion of glucose to fat Facilitates transport of amino acids into cells (permits protein synthesis) Facilitates transport of fats into adipose tissue (promotes fat storage)

Consolidation

A hypothetical process involving the gradual conversion of information into durable memory codes stored in long-term memory. The role of the hippocampal formation in memory is consolidation—converting short-term memories into long-term memories. The hippocampal formation is part of the limbic system that includes the hippocampus and several surrounding structures.

Hypertonic vs. Hypotonic

A hypotonic solution is one in which the concentration of solutes is greater inside the cell than outside of it, and a hypertonic solution is one where the concentration of solutes is greater outside the cell than inside it.

tryptophan depletion procedure

A low-tryptophan diet, followed by an amino acid drink containing no tryptophan, causes blood levels of tryptophan to be very low, reducing serotonin synthesis Found to cause most of the patients with MDD to relapse back into depression. Then, when they began eating a normal diet again, they recovered.

Tourette's syndrome

A neurological disorder beginning in childhood that involves: -muscular/vocal tics, facial grimaces, word repetition -OCD patients also have tics: Tourette's syndrome patients have obsessions and compulsions -Treatment for Tourette's includes antipsychotic drugs that block D2 receptors (haloperidol or pimozide)

adipose tissue (satiety signals)

A particular gene, called OB, normally produces , leptin, which is normally secreted by well-nourished fat cells. Because of a genetic mutation, the fat cells of OB mice in the lab were unable to produce leptin. Leptin has profound effects on metabolism and eating, acting as an anti obesity hormone. If ob mice are given daily injections of leptin, their metabolic rate increases, their body temperature rises, they become more active, and they eat less. As a result, their weight returns to normal.

frontal cortex and depression

A reliable finding in neuroimaging studies of depressed patients is hyperactivity of this region, along with decreased activity in other regions of the frontal cortex, including: -the dorsolateral PFC -the ventrolateral PFC -the ventromedial PFC -the orbitofrontal cortex A variety of successful antidepressant treatments can reliably decrease the activity of the subgenual ACC and increase the activity of other regions of the frontal cortex.

LTP and rate

A series of pulses delivered at a high rate all in one burst (i.e., 100-Hz stimulation) will produce LTP, but the same number of pulses given at a slow rate will not. This means that rapid stimulation depolarizes the postsynaptic membrane much more than slow stimulation does.

Regulatory system

A system that uses feedback information to maintain a physiological function or parameter at an optimal level. Contains four essential features: -the system variable (the characteristic to be regulated) -a set point (the optimal value of the system variable) -a detector that monitors the value of the system variable -a correctional mechanism that restores the system variable to the set point The activity of the system is regulated by negative feedback, a process whereby the effect produced by an action serves to diminish or terminate the action.

monoamine theory

A theory that holds that: -Too much norepinephrine and serotonin leads to mania -Too little leads to depression Suggested since monoamine antagonists can produce the symptoms of depression and monoamine agonists can reduce them.

system variable

A variable that is controlled by a regulatory mechanism Ex: air temperature in room with heater

hepatic portal vein

A vein connecting the capillary bed of the intestines with the capillary bed of the liver. This allows amino acids and glucose absorbed from the intestines to be delivered first to the liver for processing before being transported throughout the circulatory system.

Synaptic Plasticity and LTP

AMPA receptor: (an ionotropic glutamate receptor that controls a sodium channel) when it's open, it produces EPSPs -Increased # of new AMPA receptors during stimulation Alteration of synaptic structure -Dendritic spines form "perforated" synapses with the presynaptic terminals -Structural changes depend on entry of calcium ions which activates calcium kinase -Results in de novo proteins synthesis and gene transcriptions +This gene expression occurs wvia local machinery on dendrites

Perceptual Learning

Ability to learn to recognize stimuli that have been perceived before. The primary function of this type of learning is the ability to identify and categorize objects (including other members of our own species) and situations. Perceptual learning appears to be accomplished primarily by changes in the sensory association cortex for each sensory system (for example, changes in the visual association areas when we learn to recognize a visual stimulus).

Hyperphagia

Abnormally increased appetite for food frequently associated with injury to MVH

Nitric Oxide

Activation of NMDA receptors increases the activity of NO with CA2+ -gaseous neurotransmitter NO diffuses into presynaptic terminals and may increase glutamate release from presynaptic terminal Drugs that block NO synthesis block LTP establishment in hippocampal slices

Dopamine in Reinforcement

Activity in nucleus accumbens and the dopamine released there are responsible for reinforcement Reinforcement strengthens the connections between the neurons that detect the specific stimulus -If a stimulus causes an appetitive behavior, that stimulus can reinforce behavior

Major Affective Disorders

Affect- emotions, moods, and feeling -Usually a reflection of our experiences -In the MAD, emotional reactions are at the extremes, and may not be related to actual experiences MAD includes -Bipolar disorder-alternating cycles of +Mania +Depression -Unipolar depression: continuous, 2-3 times more frequent in women

a-MSH

Agonist of the melanocortin-4 receptor (MC4R) where it binds and inhibits feeding. Both α-MSH and AgRP bind with the MC4R. However, whereas AgRP binds with MC4Rs and causes feeding, α-MSH binds with MC4Rs and inhibits eating. CART/α-MSH neurons are activated by leptin, and NPY/AgRP neurons are inhibited by leptin

Dopamine (Reinforcement)

All of the following reinforcing stimuli result in dopamine release in the nucleus accumbens: electrical stimulation to the pathway, cocaine or amphetamine administration, or reinforcers (water, food, sex partner, receiving money) Like classical conditioning, operant conditioning involves strengthening synapses among neurons that have just been active. However, operant conditioning involves three elements: *a specific stimulus (also called a discriminative stimulus), a response, and a reinforcing stimulus.* Plays a critical role in reinforcement

Presynaptic Changes (LTP)

Alterations in synapses presumably require coordinated changes in both presynaptic and postsynaptic elements. A possible answer comes from the discovery that a gas neurotransmitter, nitric oxide (NO), can communicate retrograde messages from one cell to another. Nitric oxide is a soluble gas produced from the amino acid arginine by the activity of an enzyme known as nitric oxide synthase (NOS). Once produced, NO lasts only a short time before it is destroyed. Thus, if it were produced in dendritic spines in the hippocampal formation, it could diffuse only as far as the nearby terminal buttons, where it might produce changes related to the induction of LTP.

Fluvoxamine

An SSRI that has been found to lower the number of panic attacks in patients with panic disorder

Population EPSP

An extracellular measurement of the EPSPs produced by the synapses of the perforant path axons with the dentate granule cells The size of the first population EPSP indicates the strength of the synaptic connections before long-term potentiation has taken place.

MCH (melanin-concentrating hormone)

An orexigin that plays an important role in stimulating feeding. Mice with a targeted mutation against the MCH gene or those that receive injections of an MCH receptor antagonist eat less than wild type mice and are consequently underweight (Shimada et al., 1998). In addition, genetically engineered mice with increased production of MCH in the hypothalamus overeat and gain weight (Ludwig et al., 2001). The axons of MCH travel to a variety of brain structures that are known to be involved in motivation and movement, including the neocortex, periaqueductal gray matter, reticular formation, thalamus, and locus coeruleus Lesions of the LH produced undereating electrical stimulation produced eating -LH is a "feeding center"

Anorexia/Bulimia

Anorexia Nervosa- people eat too little -Preoccupation with food; satiety control is out of whack -Fear to become obese -Biological and social factors -Death: suicide, complications of the disease -Common: osteoporosis, lack of menstrual cycle, shrinkage of brain tissue -Could be hereditary Bulimia Nervosa- loss of control of food intake -Binges of eating, self-induced vomiting, use of laxatives

anterograde amnesia vs retrograde amnesia

Anterograde amnesia: -memory loss for information since the accident -caused by damage to the temporal lobes -Includes a disorder of relational learning Retrograde amnesia: -memory loss for information before the damage occurred Amnesia can be temporary or permanent

Pharmacological Treatment (AD)

Antidepressants: -MAO inhibitors -Tricyclic Antidepressants -SSRIs -SNRIs Ketamine: -alleviates the symptoms of treatment-resistant depression -effective but short-term treatment for severe depression Lithium: -Rapid action on the manic phase of bipolar disorder -Positive- allows patients to feel and express themselves -have adverse side effects, and its use must be monitored and managed very carefully -has an effect on the function of DISC1 in the postsynaptic density -Site of action- unknown so far +Interfere with production of phosphoinositide +Increase production of neuroprotective proteins + Electroconvulsive Therapy: -Originally used for a variety of disorders, including schizophrenia, but is now most typically limited to treatment of mania and depression. -A few seizures induced by ECT can effectively reduce symptoms of severe, treatment-resistant depression within a single treatment, or over the course of a few days Vagus Nerve Stimulation: -painless and does not elicit seizures -procedure appears helpful, particularly for patients with treatment-resistant depression, and has also been used in the treatment of other mental illness for which few or limited treatment options exist Transcranial Magnetic Stimulation: -TMS applied to the prefrontal cortex reduces the symptoms of depression without producing any apparent negative side effects However, response rate is less than 30 percent, and long-term relapse rates appear to be similar to those seen with ECT Deep Brain stimulation: -directed towards the nucleus accumbens -DBS of the nucleus accumbens reduced symptoms of depression in 50 percent of treatment-resistant patients who previously showed no response to pharmacological treatment -1 month after- 35% showed improvement while 10% showed complete remission -6 months after- 60% showed improvement and 35% showed remission

Biological basis for anxiety

Anxiety may involve reduced levels of benzo receptors and lowered sensitivity to an unknown endogenous benzo agonist CCK-4 is a peptide that induces panic attack in PD patients, but not in normal subjects Reduced serotonin activity in brain may accompany PD -Fluoxetine can be used to treat PD -Yet, the tryptophan depletion procedure, which reinstates, depression doesn't produce anxiety attacks in PD patients Altered activity within the frontal cortex

Eating behaviors

Appetitive: Behaviors that locate food Consummatory: Behaviors that place food in the gut for absorption -Biting, chewing, sucking, swallowing

Basal Ganglia Pathways

As learned behaviors become automatic they are "transferred" to basal ganglia. Frees up the transcortical circuits No longer need to deliberately think through each step Caudate nucleus and putamen

basal ganglia pathways

As we deliberately perform a complex behavior, the basal ganglia receive information about the stimuli that are present and the responses we are making, learning what to do Eventually, they take over most of the details of the process, leaving the transcortical circuits free to do something else. At this point, we don't need to consciously think about what we are doing.

classical conditioning

Association between two stimuli -The response is called an unconditioned response (UR) because it occurs unconditionally, without any special training. -The stimulus that produces it (the puff of air) is called an unconditioned stimulus (US). To establish classical conditioning, we first present the tone and then quickly follow it with a puff of air. After a while, the tone produces the blink all by itself and the synapse between the auditory neuron and the motor neuron is strengthened.

DSM-IV Criteria for MDD

At least one of the following must be present for 2 weeks -Persisent sad, anxious, or empty mood -Feelings of hopelessness, pessimism -Feelings of guilt, worthlessness, helplessness -Anhedonia- Loss of interest or pleasure in hobbies and activites that were once enjoyed -In children and teenagers the mood can be irritable rather than sad Five or more of the following symptoms during the same 2 week period: *At least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure* -Depressed mood most of the day, nearly every day -Significant weight loss when not dieting or weight gain -Insomnia or hypersomnia nearly everyday -Psychomotor agitation or retardation everyday -Fatigue or loss of energy nearly every day -Feelings of worthlessness or excessive or inappropriate guilt -Diminished ability to think or concentrate -Recurrent thoughts of death, suicide ideation without a specific plan, or a suicide attempt

NST (nucleus of the solitary tract)

Atrial baroreceptors send signals to the nucleus of the solitary tract -NST projects to AV3V region -AV3V projects to the median preoptic nucleus

Motor cortex and Basal Ganglia

BG plays an essential role in stimulus-response and motor learning Diseases in the BG lead to difficulty in learning automatic responses- Parkinson's and Huntington's diseases

place learning

Based on the configuration of visual cues (platform is stationary, but rat is put in maxe in a different spot) -Where is the platform in relation to the cues in the room?

Pharmacological Treatments (Anxiety Disorders)

Benzodiazepine: -rapid onset - less appropriate for long-term treatment -cause sedation, they induce tolerance and withdrawal symptoms, and they have a potential for abuse SSRIs: -serotonin plays a role in anxiety disorders -become the first-line medications for treating all of these disorders

Anorexia and genetic factors

Between 58 and 76 percent of the variability in the occurrence of anorexia nervosa appears to be under control of genetic factors. In addition, the incidence of anorexia nervosa is higher in girls who were born prematurely or who sustained birth trauma during complicated deliveries, which suggests that biological factors independent of heredity may play a role. The fact that anorexia nervosa is seen primarily in young women has prompted both biological and social explanations. Most psychologists favor the latter, concluding that the emphasis that most modern industrialized societies place on slimness—especially in women—is responsible for this disorder. Another possible cause could be the changes in hormones that accompany puberty. Whatever the cause, young men and women differ in their response to even a short period of fasting.

spatial memory and damage

Bilateral medial temporal lobe lesions produce the most profound impairment in spatial memory, but significant deficits can be produced by damage that is limited to the right hemisphere. Right hippocampal formation becomes active when a person is remembering or performing a navigational task while the hippocampus is required for more detailed levels of spatial navigation

Anorexia and NPY

Blood levels of NPY are elevated in patients with anorexia. An infusion of NPY into the cerebral ventricles further increased the time spent running in rats on a restricted feeding schedule. The likely explanation for this phenomenon is that, if food is not present, NPY increases the animals' activity level, which would normally increase the likelihood that they would find food. Increased levels of NPY may also play a role in the obsession with food that is often seen in patients with anorexia.

Control of Drinking

Body Loses water Detectors signal loss of water Drinking occurs Stomach fills with water, sends signal to brain Satiety mechanism inhibits further drinking Water is eventually absorbed, body fluids are back to normal

Long Term Satiety

Body weight is a determinant of food intake -Force-feeding studies: food intake falls as body weight increases -Starvation studies: gastric satiety factors are less effective when body weight has been reduced below normal levels Fat cells in body produces a signal that represents amount of fat and that subsequently alters eating -Leptin is a protein produced by fat that suppresses food intake and stimulates metabolism -Genetically obsese mouse (ob) lacks the gene that produces leptin *Daily administration of leptin normalized weight in ob mice

satiety mechanism

Brain-based mechanisms that reduce hunger or thirst related to behaviors that result in adequate intake of nutrients or water. Required because of the physiology of our digestive system. Satiety mechanisms monitor the activity of the correctional mechanism (in this case, drinking), not the system variables themselves. *When a sufficient amount of drinking occurs, the satiety mechanisms stop further drinking in anticipation of the replenishment that will occur later* Eating and drinking are anticipatory, so one needs a satiety mechanism to turn off the correctional mechanism before the set point is reached

Consequences of Long-Term Drug Treatment (Schizo)

By blocking dopamine transmission, the early antipsychotics all produced at least some symptoms resembling those of Parkinson's disease: slowness in movement, lack of facial expression, and general weakness. Side effects: -Autonomic problems (dry mouth) -Skin-eye pigmentation -Breast augmentation a more serious side effect occurred in approximately one-third of all patients who took these antipsychotic drugs for an extended period: they developed a neurological disorder called tardive dyskinesia

Classical Conditioning Processing

CS and US info is processed in the lateral nucleus of the amygdala (LA) LA projects to the central nucleus of the amygdala (CN) -US info --> UR -CS info --> Conditioned emotional response (CER) through strengthening of the synapse via the Hebb rule Within a few trials the neurons became more responsive to the tone, and many neurons that had not previously responded to the tone began doing so When they repeatedly presented the tone without the foot shock, the response extinguished and the rate of firing of the neurons in the lateral nucleus returned to baseline levels

CaM-KII

Calcium-dependent enzyme, which is inactive until a calcium ion binds with it and activates it. Many studies have shown that CaM-KII plays a critical role in long-term potentiation. -LTP could not be established in mouse hippocampal tissue with a targeted mutation that prevented the production of CaM-KII -the injection of activated CaM-KII directly into CA1 pyramidal cells strengthened synaptic transmission in those cells

LTP (cont)

Cells in entorhinal cortex project via the perforant path to synapse onto granule cells in the dentate gyrus Procedure: electrically stimulate perforant path (100 pulses/over a few seconds) -Then observe pop postsynaptic potential induced by a single pulse given repeatedly over days LTP is indexed by increase in PSP size over days and months LTP requires rapid stimulation of the perforant path LTP involves activation of synapses and depolarization of the postsynaptic membrane Involves activation of the NMDA receptor

Baroreceptors

Cells that are sensitive to blood pressure changes.

grid cells

Cells that show an evenly spaced, crystal-like coverage of the entire environment in which the animal is located

Glucoreceptors in Brain

Cerebral aqueduct is blocked --> no communication between III and IV ventricles Infusions of 5-TG (5-thioglucose) into fourth ventricle block glucose metabolism and induce eating by causing glucoprivation Infusion of glucose into the third ventricle had no effect

Osmoreceptor steps

Changes in cell volume causes changes in the membrane potential, which serve as the signal for osmometric thirst As solute concentration of the interstitial fluid increases, water leaves the cell and decreases in volume The reduction in cell volume triggers a change in firing rate, which signals thirst As solute concentration of the interstitial fluid decreases, water enters the cell and the cell increases in volume The increase in cell volume a change in firing rate, which signals satiety

Learning

Changes in the nervous system produced by experiences Nervous system changes are physical Learning allows us to adapt our behaviors to the environment Learning involves interactions among the motor, sensory, and memory systems

role of basal ganglia

Circuits responsible for OC begin in sensory association cortex and end in motor association cortex Two major pathways: -Direct transcortical connections -Connections via the BG and thalamus

Classical vs. Operant Conditioning

Classical: -Involuntary (reflexive), unlearned -Association between two stimuli (ex: tone and puff of air) Operant: -Voluntary, learned -Association between the stimulus and the response (ex: tone and pressing a lever)

Strategies for Anorexia intervention

Cognitive Behavior Therapy: -more effective than other psychotherapies in treating symptoms of bulimia -success rate of less than 50 percent and a relapse rate of 22 percent during a one-year treatment period Pharmacology: -Researchers have had more success treating bulimia nervosa with serotonin agonists such as fluoxetine (an SSRI antidepressant drug). However, fluoxetine does not help patients with anorexia -Drugs that increase appetite have not helped treat patients with Anorexia Alternative Therapies: -One novel treatment protocol for anorexia teaches patients to eat faster by placing a plate of food on an electronic scale attached to a computer that displays the time course of their actual and ideal intake. After the meal, the patients are kept in a warm room, which reduces their anxiety and their activity level. This treatment has resulted in a 75 percent success rate -Another line of research has investigated the efficacy of deep brain stimulation of the cingulate cortex. One year of cingulate stimulation produced improvements in mood, BMI, and neural circuitry in individuals diagnosed with anorexia nervosa that had not responded to previous treatment attempts -Russell and colleagues (2018) reported some reductions in eating disorder symptoms as well as lower baseline cortisol concentrations in response to a stressor (consuming a high-calorie snack) after four weeks of treatment with oxytocin.

Triglycerides

Complex molecules that contain glycerol (a soluble carbohydrate, also called glycerine) combined with three fatty acids (stearic acid, oleic acid, and palmitic acid) Cells of the body cannot directly metabolize triglycerides -They are broken down first by adipose cells and released into the blood as glycerol and fatty acids -Liver takes up glycerol and converts it into glucose

Studies of the Neurobiology of Learning and Memory

Concerned with how the brain acquires, retains and uses info What are the processes which underlie the formation of the memories? What processes determine the strength of learning?

Hypovolemia

Condition where the heart can't effectively pump blood any longer due to low intravascular fluid

AN (Arcuate nucleus)

Contains neurons that secrete NPY -NPY acts to stimulate ravenous eating and to reduce metabolism (energy conservation) -NPY neurons project to *Paraventricular hypothalamus (PVN): Modulate metabolism *LH: induce eating (via action on MCH/ orexin neurons) NPY neurons also release AGRP(Agouti-related peptide) another orexigenic peptide

Reduced Neuropil Hypothesis

Cortical pathology in Schizo- includes significant reduction of the interneuronal neuropil in prefrontal cortex

OCD categories

Counting: -People might repeatedly check burners on the stove to see that they are off and windows and locks to be sure that they are locked Checking: -Some people will wash their hands hundreds of times a day, even if their hands become covered with painful sores Cleaning -Other people meticulously clean their house or endlessly wash, dry, and fold their clothes. Avoidance: -Some become afraid to leave home because they fear contamination. If they do accidentally become "contaminated," they usually have lengthy purification rituals.

Brain stem (eating regulation)

Decerebration: Research indicates that the brain stem contains neural circuits that can detect hunger and satiety signals and control at least some aspects of food intake -Involves a transection between the diencephalon and the midbrain -Decerebrate rats can lick, chew, and swallow -Motor neurons for eating are located in the brains te The area postrema and the nucleus of the solitary tract (the AP/NST): Evidence indicates that events that produce hunger increase the activity of neurons in the AP/NST. -*In addition, lesions of this region abolish both glucoprivic and lipoprivic feeding*

Monoamine hypothesis of depression

Depression results from reduced activity of brain monoamines (DA, 5-HT and NE) Suicidal depression is related to a low level of 5-HIAA (5-hydroxyindoleacetic acid, product of 5-HT destruction of MAO) Availability or activity of one of them is reduced Reserpine (hypotensive effects) depletes monoamines --> depression (early years of treatments-up to 15% patients developed depression) Antidepressant meds increase either NE or 5-HT +Usually via blockade of monoamine reuptake Tryptophan depletion procedure -Reduces brain 5-HT levels -Reinstates depression in formerly depressed patients -Sources: cottage cheese, fish, meat, poultry, peanuts, sesame seeds

Stomach and satiety signals

Deutsch and Gonzalez (1980) found that when they removed food from the stomach of a rat that had just eaten all it wanted, the animal would immediately eat just enough food to replace what had been removed and were not fooled by the infusion of a saline solution. Do these results extend to humans? Participants reported increased fullness and reduced hunger when the glucose solution was infused into the stomach, but not the intestine. While high levels of ghrelin are present immediately before a meal, ghrelin levels fall after a meal and provide a gastric factor of satiety.

response strategy

Dictates how the organization will respond to specific incidents Activates caudate nucleus The larger a person's caudate nucleus is (and the smaller a person's hippocampus is), the fewer errors that person made.

place cells

Different neurons were found to have different spatial receptive fields; that is, they responded when the animals were in different locations. A particular neuron might fire 20 times per second when the animal was in a particular location but only a few times per hour when the animal was located elsewhere Location- specific intense activity only when the rat's head in certain position or the rat was in a specific location Place cells do NOT make up a topographic representation of space within the hippocampus

Cognitive symptoms with schizophrenia

Difficulty in sustaining attention Low psychomotor speed: reaction time, connecting numbers or letters in sequence Deficits in learning and memory Poor abstract thinking Poor problem solving

decerebration

Disconnecting the motor neurons of the brain stem and spinal cord from the neural circuits of the cerebral hemispheres (such as the cerebral cortex and basal ganglia) that normally control them Decerebrate rats can distinguish between different tastes (they drink and swallow sweet or slightly salty liquids and spit out bitter ones). They even respond to hunger and satiety signals. They drink more sucrose after twenty-four hours of food deprivation, and they drink less of it if some sucrose is first injected directly into their stomachs. They also eat in response to glucoprivation

Anorexia

Disease where people are very interested in food and express an intense fear of becoming obese, which continues even if they become dangerously underweight associated with loss of gray and white matter in the brain Some reports indicate the presence of enlarged ventricles and widened sulci in the brains of patients with anorexia, which indicate shrinkage of brain tissue Excessive eating is a symptom: -Normally, hungry rats would extend their activity by exploring the environment and searching for food, but because of their confinement the tendency to explore is expressed through wheel running. -The fact that starving rats increase their activity suggests that the excessive activity of patients with anorexia may be a symptom of starvation, not a weight-loss strategy.

GAD (Generalized Anxiety Disorder)

Disorder marked by excessive and unfounded anxiety and worry, difficulty in controlling these symptoms, and clinically significant signs of distress and disruption of their lives. The prevalence of generalized anxiety disorder is approximately 3 percent, and the incidence is approximately two times greater in women than in men.

Obesity (cont)

Disorder of metabolism (as well as eating) BW difference have a genetic component People vary in metabolic efficiency Metabolic efficiency may reflect differences in -Nonexercise activity thermogenesis (NEAT) If calories in exceed calories out, then body fat will increase

acral lick dermatitis

Dog compulsion, compulsive licking of a body part, treated via clomipramine

Effects of Dopamine Agonists

Dopamine agonists such as cocaine, amphetamine, and l-DOPA, increase positive symptoms of schizophrenia

Reinforcement Mechanism

Dopaminergic neurons

Pharmacotherapy(OCD)

Drug therapy for OCD involves drugs that are agonists for brain serotonin systems -Blockade of 5-HT reuptake improves OCD symptoms +Clomipramine +Fluoxetine +Fluvoxamine -OCD drugs require weeks to relieve OCD symptoms Antagonism of 5-HT receptors worsens OCD, whereas the tryptophan-depletion procedure does not 5-HT agonists appear to reduce intensity of the species-typical behaviors (e.g. washing)

role of the mesolimbic dopamine pathway in the positive symptoms

Drugs that act as agonists in this pathway (such as cocaine and amphetamine) strongly reinforce behavior and can also produce the positive symptoms of schizophrenia patients with greater amounts of dopamine release showed greater increases in positive symptoms Reviews of these studies concluded that there might be modest increases in the numbers of D2 receptors in the brains of people with schizophrenia but that it seems unlikely that these increases are the primary cause of the disorder

tricyclic antidepressants

Drugs that inhibit the reuptake of 5-HT and norepinephrine by terminal buttons. By reducing reuptake, the drugs keep the neurotransmitter in the synapse and available to bind with the postsynaptic receptors. This helps prolong the postsynaptic potentials in these neurotransmitter systems

Glucocoticoids

During vigorous exercise or stress, the brain causes the adrenal cortex to release these hormones These hormones promote the breakdown and utilization of muscle glycogen

enriched environment

Environment that offers a rat many chances to learn Results in: -thicker cortex -More glial cells -More synapses -More vasculature

Factors that cause Obesity

Environmental: -In many societies, inexpensive, convenient, good-tasting, high-calorie food is readily available, which promotes an increase in intake. Fast-food restaurants are close at hand, parking is convenient (or even unnecessary at restaurants with drive-thru windows), and portion sizes have increased -For example, the transition to college life is often associated with changes in eating and physical activity patterns. Longitudinal studies of college students have confirmed increases in weight and body fat across four months -Some parts of the U.S. are considered food deserts, or areas where fresh fruits, vegetables, whole grains and other staples of a healthy diet are not readily available and there may be few, if any, grocery stores or markets Physical Activity: -The proportion of people employed in jobs that require a high level of physical activity has decreased considerably, which means that on the average we need less food than previous generations did -In one study, investigators found that the people who were overweight remained seated 2.5 hours per day more than the lean people. Genetic Factors: -Twin studies suggest that between 40 and 70 percent of the variability in body fat is due to genetic differences. Twin studies have also found strong genetic effects on the amount of weight that people gain or lose when they are placed on high- or low-calorie diets -People with an efficient metabolism have calories left over to deposit in the long-term nutrient reservoir, and these calories accumulate in the form of increased adipose tissue. Researchers have referred to this condition as a "thrifty phenotype." In contrast, people with an inefficient metabolism (a "spendthrift phenotype") can eat large meals without getting fat. Leptin: -So far, researchers have found several cases of familial obesity caused by the absence of leptin produced by mutations of genes responsible for production of leptin or the leptin receptor. -Treatment of people who are leptin-deficient with injections of leptin has dramatic effects on body weight. -However, it turns out that most people that are obese already have a high blood level of leptin, and increasing this level with injections of the peptide has little or no effect on their food intake.

DIsordered Sleep (Cont)

Evidence also suggests that up to 90 percent of people who experience an episode of depression report changes in their patterns of sleep and usually have difficulty initiating and maintaining a good night's sleep Sleep deprivation has been found to reduce symptoms of depression. However, patients with depression whose mood remains stable will probably not benefit from sleep deprivation, whereas those whose mood fluctuates probably will.

Kidneys and Water/Salt Balance

FLuid regulation is controlled by controlling intake and excretion of water ad salt Kidney: -In response to low blood volume, the kidneys are responsible for the presence of the hormone ANGIOTENSIN following a cascade of biochemical events. -Therefore, reduced blood flow to the kidneys causes water and salt to be retained until fluid balance can be restored. Nephrons of the kidneys control excretion of: -Water *Increases vasopressin (from posterior pituitary) release increases water retention -Salt *Increases aldosterone (from adrenal cortex) levels result in salt retention

Intestinal Factors

Feinle, Grundy, and Read (1997) had people swallow an inflatable bag attached to the end of a thin, flexible tube, and the people reported sensations of fullness like those experienced after eating a meal. This demonstrates that stomach and intestinal satiety factors can interact. After food reaches the stomach, it is mixed with hydrochloric acid and pepsin, an enzyme that breaks proteins into their constituent amino acids.--> As digestion proceeds, food is gradually introduced from the stomach into the duodenum. --> The duodenum controls the rate of stomach emptying by secreting a peptide hormone called cholecystokinin (CCK). CCK is secreted in response to the presence of fats, which are detected by receptors in the walls of the duodenum. --> In addition to stimulating contraction of the gallbladder, CCK causes the pylorus to constrict and inhibits gastric contractions, keeping the stomach from giving the duodenum more food. Peptide YY3−36 (PYY), is released by the small intestine after a meal in amounts proportional to the calories that were just ingested --> Injections of PYY significantly decreased the size of meals eaten by members of several species, including rats and both lean and obese humans In addition, Stoeckel et al. (2008) found that the amount of PYY released after a meal correlates positively with people's ratings of satiety.

Induction

First phase of LTP Induction- high frequency stimulation Where it could be induced- many areas of the brain (first found- hippocampus-dentate) Receptors involved-NMDA, AMPA Second messenger cascade(s)- start with Ca2+ influx, kinases, CREB (cAMP response element binding- a gene transcription factor)

LTP steps

First, a single pulse of electrical stimulation is delivered to the perforant path, and then the resulting population EPSP is recorded in the dentate gyrus. Long-term potentiation can be induced by stimulating the axons in the perforant path with a burst of approximately 100 pulses of electrical stimulation, delivered within a few seconds. Evidence that long-term potentiation has occurred is obtained by periodically delivering single pulses to the perforant path and recording the response in the dentate gyrus. If the response is greater than it was before the burst of pulses was delivered, long-term potentiation has occurred.

negative symptoms of schizophrenia

Flattened emotional response Poverty of speech Lack of initiative and persistence, no curiosity Anhedonia Social Withdrawal and diminished affect Echolalia- repetition of recently heard words

Issues for Rational Therapies for Obesity

Food intake and metabolism are controlled on multiple levels -Intervention on one level may result in compensation on another level *EX: Subjects who overeat and stretch their stomach after stapling procedure Obesity is a multifactorial disorder -One therapy might not fit all Obesity is a long-term disorder: requires long-term treatments

Example of CC

For example, an eye-blinking response can be conditioned to a tone. If we direct a brief puff of air toward an eye, the eye will automatically blink. We present tones (auditory stimuli), each followed very quickly (500 ms later) by a puff of air. After several trials the eye begins to close even before the puff of air occurs.

operant conditioning

Form of learning in which a reinforcing or punishing outcome follows a specific behavior in a specific situation. The reinforcer increases the likelihood of the behavior occurring again in the future, while the punisher decreases it.

Quirk, Repa, and LeDoux

Found evidence for synaptic changes in the lateral nucleus of the amygdala

lamina terminalis

Found in the hypothalamus, in a region that borders the anteroventral tip of the third ventricle (the AV3V) Contains two specialized circumventricular organs: -the OVLT -the SFO Injections of concentrated saline directly into this region produce drinking

Feeding termination (cont)

Gastric factors -Stomach is not required for feelings of hunger -Nutrient receptors monitor calories in stomach *Rats adjust their subsequent meals when food is withdrawn from their stomach via a fistula (sham-feeding) Intestinal factors -Axons from the gut are sensitive to glucose, amino acids and fatty acids -In stomach: food + HCl + pepsin (digestion of proteins) -In duodenum: food + bile + pancreatic enzymes -Food infusion into the duodenum suppresses sham feeding in the rat -CCK

Factors in Developing OCD

Genetic: -not all cases of OCD have a clear genetic origin; the disorder sometimes occurs after brain damage caused by various means, such as birth trauma, encephalitis, and head trauma increased activity in frontal lobes: -functional-imaging studies consistently showed increased activity of the caudate nucleus and the orbitofrontal cortex Damage to basal ganglia

Genetic factors (Affective disorders)

Gershon et al. (1976) found that if one member of a set of monozygotic twins was diagnosed with an affective disorder, the likelihood that the other twin was similarly diagnosed was 69 percent. In contrast, the concordance rate for dizygotic twins was only 13 percent. The RORA, GRM8, and RORB genes were all thought to be involved

Metabolism phases

Glucose satisfies most of the body's energy requirements, by replenishing the short-term reservoir in the liver. Glucose is converted to glycogen in the liver Excess glucose is converted to triglycerides and stored in adipose tissue. If enough carbohydrates are consumed, fats are stored in adipose tissue. Amino acids are used for protein synthesis. Unused amino acids are converted to triglycerides and stored in adipose tissue. The fasting phase begins and the body must live on the nutrients stored in the short-term and long-term reservoirs. Glycogen stored in the liver is converted to glucose, which is used by the nervous system. Triglycerides are made of fatty acids and glycerol. When broken down, the fatty acids are used by the body, while the central nervous system uses glycerol, after converting it to glucose.

Absorptive phase

Glucose: -As we start absorbing the nutrients, the level of glucose in the blood rises. --> -This rise is detected by cells in the brain, which tells the pancreas to stop secreting glucagon and to begin secreting insulin. --> -The insulin permits all the cells of the body to use glucose as a fuel. Amino acids: A small proportion of the amino acids received from the digestive tract are used as building blocks to construct proteins and peptides; the rest are converted to fats and stored in adipose tissue. Fat: Fat is not used as a fuel at this time. Instead, it is stored in adipose tissue.

positive symptoms of schizophrenia

Hallucinations -Auditory is most common Thought disorders -may jump from one topic to another as new associations come up -may use meaningless words or choose words for rhyme rather than for meaning. Delusions -Persecution -Grandeur -Control

Detector Cells in body

Heart: -These baroreceptor cells are stretch sensitive and detect when blood volume in the heart falls. -Reduced blood flow to the heart increases drinking and severing the nerves to the atrial baroreceptors decreases drinking, demonstrating the important role of these receptor cells

Heritability of Schizophrenia

Heritability is a strong indicator of a biological basis for schizo Adoption studies -Adult schizo that were adopted as children are likely to have schizo biological relatives Twin studies -Concordance rates for schizo are higher for identical that for fraternal twins No single gene is responsible for schizo, but genes can pass on a susceptibility to develop schizo

Leptin levels

High levels of leptin stimulate the release of the anorexigens CART and α-MSH and inhibit the release of the orexigens NPY and AgRP. Low levels of leptin have just the opposite effects: the anorexigenic CART/α-MSH neurons are not activated and the orexigenic NPY/AgRP neurons are not inhibited

Serotonin and Compulsions

Human compulsions -Trichtillomania refers to compulsive hair pulling -Onychophagia refers to compulsive nail biting -Both compulsions are reduced by clomipramine (serotonin agonist) Dog compulsions -Acral lick dermatitis refers to compulsive licking by a dog of a body part; ALD is treated by administration of clomipramine -Disorder is genetic, almost exclusively in large breeds (Great Danes, Labrador retrievers and German shepherds)

susceptibility hypothesis

Hypothesis that says that people would carry the "Schizo gene" but would not express it => the environment is such that Schizo is never triggered Evidence: equal % of Schizo in the offspring of both schizophrenic and non-Schizophrenic members of monozygotic twins Much higher chance in older fathers (1/47 with fathers over 50)

absorptive phase of metabolism

INSULIN PROMOTES UTILIZATION AND STORAGE OF NUTRIENTS Increases conversion of glucose to glycogen in liver and muscles Increases conversion of glucose to fat Facilitates transport of amino acids into cells (permits protein synthesis) Facilitates transport of fats into adipose tissue (promotes fat storage)

short-term memory

If information is meaningful or salient enough to be passed on from sensory memory, it will move to the short-term memory stage This stage is longer than sensory memory, but still limited to seconds or minutes. The memory capacity is limited to a few items, such as the digits in a phone number or the letters in a name. -Capacity can be expanded through chunking The length can be extended through rehearsal

Aldosterone

In the kidney Increased amount increases salt retention

Vasopressin

In the kidney Increased amount release increases water retention

Monochorionic vs dichorionic

In the past, most researchers assumed that discordance for schizophrenia in monozygotic twins must be caused by differential exposure to environmental factors after birth Found that the concordance rate for schizophrenia much higher in the monochorionic twins

ketones

In times of fasting, the liver oxidizes some of the fatty acids into ketones -The liver cannot use ketones but all other tissues can (including the brain)

Genetic factors (schizo)

Incidence is less than 50 percent, which means either that several genes are involved or that having "schizophrenia genes" imparts a susceptibility to develop schizophrenia Mutations: -DISC1: also appears to increase the incidence of other mental disorders Twin and Adoption Studies -concordance rate for schizophrenia was 10.7 percent in the dichorionic twins and 60 percent in the monochorionic twins. -These results provide strong evidence for an interaction between prenatal heredity and environment. Paternal Age: -children of older fathers are more likely to develop schizophrenia -caused by mutations in the spermatocytes, the cells that produce sperms Epigenetics: -Methylation of histone proteins prevents the expression of particular genes. important cause of schizophrenia is the disturbance of prenatal brain development that, in most cases, ultimately manifests itself after puberty

Overview of LTP

Increased glutamate release NMDA/AMPA receptors Calcium entry into dendritic spine -CaM-KII activity NO feedback onto presynaptic cell

positive reinforcement

Increasing behaviors by presenting positive stimuli, such as food. A positive reinforcer is any stimulus that, when presented after a response, strengthens the response. Reinforcement occurs in context of a stimulus Stimulus can then elicit the response

Perceptual Learning: Role of Cortex

Info from thalamus is sent to extrastriate cortex, then to the visual association cortex VAC is divided into two streams -Ventral stream: what -Dorsal stream: where Memory -Perceptual learning causes changes to neural ciruits, which become active again when the same stimulus is presented +Constitutes the recognition of the stimulus- the readout of the visual memory Specific kinds of visual info can activate specific regions of the extrastriate cortex -Retrieval of memories of pictures, sounds, movements, or spatial locations activates the appropriate regions of the sensory association cortex

Ingestive Behaviors

Ingestive behaviors are correctional mechanisms that replenish the body's depleted stores of water or nutrients. Because of the delay between ingestion and replenishment of the depleted stores, ingestive behaviors are controlled by satiety mechanisms as well as by detectors that monitor the system variables.

Fluids

Intracellular fluid: fluid portion of the cytoplasm of cells -Contains 2/3 of body's water Extracellular fluid: All other fluids

AV3V vs ACC

Intravenous injections of concentrated saline into human volunteers activates several brain regions, including the AV3V and the anterior cingulate cortex When the volunteers were permitted to drink water, they did so, and almost immediately reported that their thirst had been satisfied. Simultaneously, the activity in the anterior cingulate cortex returned to baseline values. However, the activity in the AV3V remained high. The fall in the activity of the anterior cingulate cortex appears to reflect the activation of this satiety mechanism.

Transcortical pathways

Involved in acquiring episodic memories and complex behaviors that involve deliberation or instruction A memorized set of rules provide a script to follow

How does ECT produce antidepressant effect?

It has been known for a long time that seizures have an anticonvulsant effect: ECT decreases brain activity and raises the seizure threshold of the brain, making it less likely for another seizure to occur The changes associated with this effect may be responsible for reducing the symptoms of depression.

Taijin Kyofusho

Japanese fear of offending or embarrassing others can be effectively treated with drugs that increase activity in the serotonin system

Obesity Treatments

Jaw wiring Gastric stapling reduces stomach volume Intestinal bypass reduces food absorption -Diarrhea and flatulence are problematic -Bacterial overgrowth and vitamin deficiencies can occur after intestinal bypass surgery Pharmacological: -Suppression of appetite (fenfluramine) *Cardiac problems with fenfluramine (PPH, primary pulmonary hypertension; heart valve disorder) -Herbal preparations that reduce appetite (ephedrine) -Blockage of fat absorption (Xenical) Exercise can benefit in obesity treatment

Dual Hypovolemic Sensors

Kidneys contain cells that detect decreases in the blood flow to this organ (Result of blood loss) Cells secrete renin --> catalysis of angiotensinogen=> angiotensin I=> angiotensin II Angiotensin II is formed when blood flow through kidneys is reduced -AII has -Baroreceptors within atrium of heart signal blood volume: Reduced stress results in drining

Extrastriate Cortex and Perceiving Motion

Kourtzi and Kanwisher (2000) found that specific kinds of visual information can activate very specific regions of the extrastriate cortex. The investigators presented participants with photographs that implied motion—for example, an athlete getting ready to throw a ball- activated the MT/MST areas Even though the photographs did not move, the participants' memories presumably contained information about movements they had previously seen.

History (schizo)

Kraeplin (1856-1926) first marked Schizo as a distinct disorder (collaborators- Alzheimer, Nrodmann and Nissl, in Munich, end of the 19th century) -Wrote a book, Dementia Praecox and Paraphrenia (1919) -Emphasized the chronic and progressive nature of the disease -Identified 11 subtypes

Aphagia (lack of eating) can be produced by lesioning the:

LH

LH vs VMH

LH is a "feeding center," so lesions produce undereating VMH is a "satiety center," so lesions produce ravenous overeating

LTP vs LTD

LTD: -low-frequency stimulation -decreased synaptic strength -fewer AMPA receptors in postsynaptic membrane LTP: -higher frequency stimulation -strengthening synaptic strength -more AMPA receptors

Role of Glutamate

LTP is a series of synaptic changes LTP among glutamate synapses in the lateral amygdala help establish conditioned emotional response -Synaptic changes in the system increases EPSP (excitatory postsynaptic potential) to the postsynaptic cell

L-LTP

LTP that lasts more than a few hours requires protein synthesis Apparently, the protein synthesis is required for establishing the later phase of long-lasting LTP, which normally occurs within an hour of the establishment of E-LTP. PKM-zeta appears to have several important roles related to LTP. It helps move AMPA receptors to the terminal membrane, and it remains active to perpetuate this contribution to LTP through a positive feedback loop. The long-lasting activity of PKM-zeta may be the critical component that allows memories to last a lifetime

Motor Learning

Learning that establishes changes (responses) within motor systems following a stimulus *Requires sensory guidance from the environment.* Differs from other forms of learning primarily in the degree to which new forms of behavior are learned. *The more novel the behavior, the more the neural circuits in the motor systems of the brain must be modified.*=[

Role of hypothalamus in satiety

Leptin produces behavioral and metabolic effects by binding with receptors on neurons that release NPY and AGRP (in the arcuate n) AN contains two other systems of anorexigenic peptide hormones -CART -a-MSH -Released by CART neurons -agonists of the MC4-R a-MSH and AGRP both bind to MC4-R -a-MSH will reduce eating -AGRP will increase eating

ventromedial hypothalamus

Lesions of the VMH produced overeating, electrical stimulation suppressed eating VMH is a "satiety center"

Effect of Tryptophan Depletion

Little or no effect on the mood of healthy individuals, but it does lower the mood of people with a personal or family history of affective disorders

Glucoreceptors in Liver

Liver contains glucoreceptors that report to brain via vagus nerve, nucleus of solitary tract Infusions of 2-DG into hepatic portal vein produce immediate eating -Transection of the vagus prevents the stimulatory effect of 2-DG on eating -2,5-AM (2,5 anhydro-D-mannitol) blocks glucose metabolism (like 2-DG) AND increases firing rate in the vagus (which reports to the brain) Injections of glucose into peritoneal cavity reduced eating in hungry dogs, while IV injections did not -Infusion of glucose into the hepatic portal vein produced long-lasting satiety: hepatic portal vein is a direct route to the liver -Infusions of small amounts of fructose into the hepatic portal vein also suppress eating; fructose does not cross into brain

Orbitofrontal cortex

Located at the base of the frontal lobes Inputs- dorsomedial thalamus, temporal and other areas of frontal cortex, ventral tegmental area, amygdala and olfactory system Outputs- cingulate cortex, hippocampal formation, temporal cortex, lateral hypothalamus, amygdala OC serves as interface between mechanism involved in automatic emotional responses and mechanisms involved in control of complex behaviors

Biological Bases of PD

MZ twins have a higher concordance rate for PD than DZ twins PD is more likely in families or patients with the disorder -*Caused by a duplicated region on chromosome 15* PD can be triggered by events that activate the ANS -Lactic acid injections (reactions- partly heritable) -Caffeine consumption -Breathing air containing high levels of carbon dioxide

Postsynaptic Changes (LTP)

Many studies have found that the establishment of LTP also includes changes in the size and shape of dendritic spines. For example, Bourne and Harris (2007) suggest that LTP causes the enlargement of thin spines into fatter, mushroom-shaped spines. Nägerl et al. (2007) found that the establishment of LTP even causes the growth of new dendritic spines.

detector

Mechanism that monitors the value of the system variable and signals when the system variable deviates from its set point Ex: Thermostat

correctional mechanism

Mechanism that restores the system variable to the set point Ex: Closure of the contacts turns on the correctional mechanism—the coils of the heater

partial agonist

Medication that produces a weaker, or less efficacious, response than an agonist.

nondeclarative memory

Memories that we are not necessarily conscious of. Nondeclarative memories do not seem to require memorization or include facts or experiences. Instead, nondeclarative memories control motor behaviors. You learn to make automatic adjustments with your hands and body.

Evidence for Brain Abnormalities (MAD)

Metabolic activity in subgenual (medial) prefrontal cortex is significantly reduced in patients with depression Decreased metabolism is evident in depressed and bipolar patients

Evidence for Biological Basis (MAD)

Monopolar depression is amenable to physical treatments including: MAO inhibitors (iproniazid) -Increases release of dopamine, norepinephrine and serotonin Tricyclic antidepressants: Serotonin reuptake inhibitors -Specific serotonin reuptake inhibitors (SSRIs), ex: Prozac -5-HT and NA reuptake inhibitors (SNRIs) Electroconvulsive Shock Therapy (ECS) Sleep Deprivation

fasting phase of metabolism

Most body organs (except the brain) use fatty acids The brain uses glucose from 3 sources -Glycerol converted to glucose in the liver -Liver glycogen converted to glucose -Muscle protein converted to amino acids which the liver converts to glucose during prolonged fasting In times of fasting, the liver oxidizes some of the fatty acids into ketones -Liver cannot use ketones but all other tissues can (including the brain) Muscle tissue can use its own stored glycogen

Cortical regions and recognition

Most investigators agree that the ventral stream is involved with the what of visual perception and the dorsal stream is involved with the where. Many studies have shown that lesions that damage the inferior temporal cortex—the end of the ventral stream—disrupt the ability to discriminate among visual stimuli. These lesions impair the ability to perceive (and thus to learn to recognize) particular kinds of visual information.

NPY/ AgRP

Neurotransmitter found in several brain areas, most notably the hypothalamus, that stimulates eating behavior and reduces metabolism, promoting positive energy balance and weight gain Increasing NPY production in the hypothalamus produces greater eating in rats, and ghrelin receptors are found on NPY neurons NPY produces the AgRP, which appear to act together. AgRP, like NPY, is a potent and extremely long-lasting orexigen. Infusion of a very small amount of this peptide into the third ventricle of rats produces an increase in food intake that lasts for six days

OCD and Brain Changes

OCD may involve damage to basal ganglia, cingulate gyrus, and prefrontal cortex OCD is associated with neurological syndromes that involve damage/degeneration to the basal ganglia (Huntington's Disease) Associated with increased activity within the frontal lobes -Drug therapy reduces frontal lobe activity -Surgical transection of the subcortical frontal lobe leads to improvement in OCD (as did a gunshot wound to the head)

Endocannabinoids

One of the effects of the THC contained in marijuana is an increase in appetite—especially for highly palatable foods. Cannabinoid agonists have been used to increase the appetite of cancer patients, and until adverse side effects were discovered, cannabinoid antagonists were used as an aid to weight reduction. Cannabinoid agonists have been used to increase the appetite of cancer patients, and until adverse side effects were discovered, cannabinoid antagonists were used as an aid to weight reduction.

Basal ganglia and operant conditioning

Operant conditioning entails strengthening the connections between neural circuits that detect a particular stimulus and neural circuits that produce a particular response. The circuits that are responsible begin in various regions of the sensory association cortex, where perception takes place, and end in the motor association cortex of the frontal lobe, which controls movements.

PKM-zeta

PKM-zeta appears to have several important roles related to LTP. It helps move AMPA receptors to the terminal membrane, and it remains active to perpetuate this contribution to LTP through a positive feedback loop. The long-lasting activity of PKM-zeta may be the critical component that allows memories to last a lifetime

Postpartum Depression

PPD is a condition that describes a range of physical and emotional changes that many mothers have after giving birth. There are three types: -"Baby blues" -PPD -Postpartum psychosis

postpartum psychosis

PPP is a very serious mental illness for new mothers Can happen quickly, often within the first 3 months after childbirth Women can lose touch with reality often having auditory hallucinations (hearing things that aren't actually happens) and delusions Other symptoms include insomnia, agitation, and anger Women who have PPP need treatment immediately and almost always needs medication Hospitalization may be necessary b/c women are at risk for hurting themselves or others

promoter region

Part of 5-HT transporter gene Comes in two forms: -Short -Long found that depressed people with two long alleles for this gene were more likely to respond to treatment with an antidepressant drug than were those with one or two short alleles. In fact, people with two long alleles were even more likely to respond to the placebo True role is still unclear

AP/NST (area postrema and the nucleus of the solitary tract)

Parts of the medulla that receive taste information from the tongue and hunger signals from the liver In addition, this region contains a set of detectors that are sensitive to the brain's own fuel: glucose. All this information is transmitted to regions of the forebrain that are more directly involved in control of eating and metabolism.

PYY

Peptide YY3-36 digestive tract hormone; sends "I'm not hungry" signals to the brain *released by the small intestine after a meal in amounts proportional to the calories that were just ingested* PYY binds with an inhibitory autoreceptor found on NPY/AgRP neurons in the arcuate nucleus of the hypothalamus. When PYY binds with this receptor, it suppresses the release of NPY and AgRP and suppresses food intake

Glucagon

Peptide hormone that stimulates the conversion of glycogen (stored in the liver) into glucose

Cortical Regions and Remembering

Perceptual learning involves changes that establish new neural circuits When the same stimulus is seen again and the same pattern of activity is transmitted to the cortex, these circuits become active again. This activity constitutes the recognition of the stimulus—the readout of the visual memory. Damage to regions of the brain involved in visual perception not only impairs the ability to recognize visual stimuli but also disrupts people's memory of the visual properties of familiar stimuli.

between-session learning

Period of time when the memory of motor behavior is improved, following the initial trials when no additional practice occurs Improvement is made through consolidation and reconsolidation of the memory, with REM and slow-wave sleep being associated with enhanced aspects of motor learning in some motor learning tasks promoting LTP

Types of Delusions

Persecution: others are following, plotting, and conspiring against oneself Grandeur: Thinks of one as more powerful and important than in actuality Control: He or she is controlled by others through radar or a tiny receiver in the brain

Protein Synthesis Steps

Presynaptic membrane depolarization Presynaptic release of glutamate Postsynaptic activation of ligand- and voltage-gated NMDA receptors Entry of calcium ions into the postsynaptic cell, and subsequent activation of enzymes such as CaM-KII Movement of AMPA receptors into the postsynaptic membrane Postsynaptic NOS increases release of NO, which retrogradely travels to presynaptic terminal to increases release of glutamate

lateral hypothalamus

Produces peptides, melanin-concentrating hormone (MCH) and orexin, (also known as hypocretin) MCH and orexin are orexigens, "appetite-inducing chemicals." Injecting either of these peptides into the lateral ventricles or various regions of the brain induce eating. Axons travel to a variety of brain structures that are known to be involved in motivation and movement, including the neocortex, periaqueductal gray matter, reticular formation, thalamus, and locus coeruleus Part of the pathway involves a system of neurons that secrete a neurotransmitter called neuropeptide Y (NPY), an extremely potent stimulator of food intake. Infusing NPY into the hypothalamus produces ravenous, almost frantic eating. NPY terminals release AgRP, which can work together to act as a long-lasting orexigen Endocannabinoids: Cannabinoid agonists have been used to increase the appetite of cancer patients, and until adverse side effects were discovered, cannabinoid antagonists were used as an aid to weight reduction.

Role of the Prefrontal Cortex

Provides input to the VTA (ventral tegmental area) -Increases the amount of dopamine in the nucleus accumbens -Involved in devising strategies, making plans, evaluating progress made toward goals, etc

Epidemiology (schizo)

Rate of prevalence is similar world-wide over different populations About 1% life time risk for schizo-like disorders Common to all parts of the world and cultures Affects people as they reach reproductive age -Accounts for around 75% of all mental health expenditures in industrialized countries

Nucleus Accumbens and Reinforcement

Rats will self-inject dopamine agonists directly into the nucleus accumbens Microdialysis studies indicate that increased extracellular dopamine levels in nucleus accumbens are produced by: -Drugs of abuse (amphetamine and cocaine) -Natural reinforcers (food for hungry rat) Dopamine receptor antagonists interfere with reinforcement

LH Control of Eating

Recent studies indicate a role for LH neurons in the control of eating -Selective lesions of LH cell bodies reduce eating -Excitation of LH cells by glutamate stimulates eating *Glutamate antagonists in the LH reduce eating -LH cells contain two peptide neurotransmitters *Melanin-concentrating hormone (MCH) *Orexin (hypocretin)

MC4-R

Receptor that a-MSH is an agonist to regulation of food intake and energy balance a-MSH and AGRP both bind to MC4-R -a-MSH will reduce eating -AGRP will increase eating

NMDA receptor

Receptor that is found in the hippocampal formation, especially in field CA1. The NMDA receptor controls a calcium ion channel. This channel is normally blocked by a magnesium ion (Mg2+), which prevents calcium ions from entering the cell even when the receptor is stimulated by glutamate. But if the postsynaptic membrane is depolarized, the Mg2+ is ejected from the ion channel, and the channel is free to admit Ca2+ ions. Thus, calcium ions enter the cells through the channels controlled by NMDA receptors only when glutamate is present and when the postsynaptic membrane is depolarized. Drugs that block the NMDA receptor block the formation of LTP

Insulin (satiety signal)

Receptors appear to detect insulin present in the blood, which tells the brain that the body is probably in the absorptive phase of metabolism. In this way, insulin may serve as a satiety signal. Infusing insulin into the third ventricle inhibits eating and causes a loss of body weight

MT/MST

Region of the visual association cortex that responds to movement Participants looked at static scenes and were able to judge their movement

Treating Obesity

Reinforcement and Stress: -stress and anxiety can cause reinstatement of the eating or drug taking, apparently by means of similar brain mechanisms (Nair et al., 2009). -Both dopamine, which plays an important role in reinforcement, and corticotropin-releasing hormone (CRH), which plays an important role in stress, are involved in relapse of food- and drug-seeking behavior. Surgical Interventions: -The procedures they have developed (called bariatric surgery) are designed to reduce the amount of food that can be eaten during a meal or interfere with absorption of calories from the intestines. -Bariatric surgery has focused on the stomach, the small intestine, or both. -RYGB procedure Pharmacological Intervention: -Suppress Eating *Fenfluramine stimulates the release of 5-HT, but was found to cause heart issues and was pulled from the market. *Sibutramine has similar effects on eating, but a study of people who were taking the drug found increased incidence of heart attacks and strokes, so this drug, too, was withdrawn from the market -Prevent Digestion *Orlistat interferes with the absorption of fats by the small intestine. As a result, about a third of the fat in the person's diet passes through the digestive system and is excreted with the feces. Unfortunately, as a result, the drug induced gastrointestinal side effects in 15-30 percent of users. Behavioral Interventions: Exercise consumes calories, of course, but it also appears to have beneficial effects on metabolic rat

Episodic Learning

Remembering sequences of events (episodes) that we witness Requires us to keep track of and remember not only individual events but also the order in which they occur.

AMPA Receptors

Research indicates that strengthening of an individual synapse is accomplished by insertion of additional AMPA receptors into the postsynaptic membrane of the dendritic spine (Shi et al., 1999). AMPA receptors control sodium channels; thus, when they are activated by glutamate, they produce EPSPs in the membrane of the dendritic spine. Therefore, with more AMPA receptors present, the release of glutamate by the presynaptic terminal button causes a larger excitatory postsynaptic potential. In other words, the synapse becomes stronger.

Decerebration

Research indicates that the brain stem contains neural circuits that can detect hunger and satiety signals and control at least some aspects of food intake -Involves a transection between the diencephalon and the midbrain -Decerebrate rats can lick, chew, and swallow -Motor neurons for eating are located in the brain stem

long term reservoir

Reservoir is filled with fat tissue and triglycerides What fuels the rest of our body, besides the CNS When the digestive system is empty, activity of the sympathetic axons that innervate adipose tissue, the pancreas, and the adrenal medulla, increases. All three effects (direct neural stimulation, secretion of glucagon, and secretion of catecholamines) cause triglycerides in the long-term fat reservoir to be broken down into glycerol and fatty acids. The fatty acids can be directly metabolized by cells in all of the body except the brain, which needs glucose. The liver takes up glycerol and converts it to glucose. That glucose, too, is available to the brain. The cells of the body require the presence of insulin (which binds to insulin receptors) in order to take up and utilize glucose. Cells in the brain do not contain insulin receptors, and these cells can absorb glucose even when insulin is not present.

Punishment

Responses that are followed by "unfavorable" consequences (punishing stimuli) are less likely to occur in the future

Heritability of Affective Disorders

Rosenthal (1971)- Close relatives of people who suffer from affective psychoses are 10 X more likely to develop an AD Gershon et al (1976)- In monozygotic twins if one twin has an AD, the chances for the other twin having a similar disease is 69%. Concordance rate in dizygotic twins- 13%

Hebb Rule

Rule that states if a synapse repeatedly becomes active at about the same time that the postsynaptic neuron fires, changes will take place in the structure or chemistry of the synapse that will strengthen it Introduction of tone causes an active but weak auditory synapse--> Puff is presented immediately afterward, and the strong somatosensory synapse becomes active and makes the motor neuron fire--> The act of firing then strengthens any synapse with the motor neuron that has just been active--> After several increments, the synapse between both neurons becomes strong enough to cause the motor neuron to fire by itself.

Theoretical Account of Operant Conditioning

S-R learning, connections between the sensory association cortex and the motor cortex are made -What pathways mediate this connection? *Transcortical connections +Complex behaviors that use instruction *Basal ganglia +As behavior becomes more habitual, the basal ganglia take over- the BG is in constant contact with frontal cortex -BG lesions disrupt instrumental conditioning and habit learning

SSRI vs SNRI

SSRI - selective serotonin reuptake inhibitor, anti-depressants (celexa, zoloft, paxil, lexapro) -reduces the symptoms of obsessive-compulsive disorder and social phobia SNRI - Serotonin-norepinephrine reuptake inhibitors, also anti-depressants, acts on 2 NTs, more effective, rarer -produce most of their effects as antagonists at the 5-HT transporters

Brain damage and Schizo

Schizophrenics exhibit enlarged brain ventricles, which suggests loss of brain cells Abnormal regions include -Prefrontal cortex -Medial temporal lobes -Medial diencephalon

Environmental factors (schizo)

Season of birth -Seasonality effect Viral epidemics -more likely to contract a viral illness during the fall or winter -Vitamin D deficiency Population density -likelihood of developing schizophrenia is approximately three times higher in people who live in the middle of large cities than in those who live in rural areas Prenatal malnutrition -underweight women are more likely to give birth to babies who later develop schizophrenia and that low-birth-weight babies have a higher incidence of schizophrenia -prenatal stressors such as exposure to a terrorist attack are associated with increased incidence of schizophrenia in offspring Substance abuse -Excessive alcohol intake increased the risk of schizophrenia only if the mother drank more than 210 ml of pure alcohol per week -tobacco use was associated with increased risk of schizophrenia Interactions Birth trauma Maternal stress can compromise the immune system of the mother and lead to a chance in contracting a viral infection

Maintenance

Second phase of LTP Requires proteins synthesis (local) Persistence of LTP-related changes-days, months, even years Structural changes caused by LTP- increased number of synapses, perforated synapses, number of vesicles in presynaptic terminal, complexity of synapse

semantic vs episodic memory

Semantic memories are less specific than episodic memories. -For example, knowing that the sun is a star involves a less specific memory than being able to remember when, where, and from whom you learned this fact. Semantic memories can be acquired gradually, over time while episodic memories must be learned all at once

Learning Process

Sensory Input--> Sensory Memory -(Attention)-> Short Term -(Encoding)-> -Maintenance Rehearsal multiple times Long Term Memory -(Retrieval)-> Short Term Memory

clomipramine

Serotonergic agonists that alleviate the symptoms of obsessive-compulsive disorder by reducing the strength of innate tendencies for counting, checking, cleaning, and avoidance behaviors that may underlie this disorder

Basal ganglia and motor learning

Several experiments have shown that *people with diseases of the basal ganglia have deficits that can be attributed to difficulty in learning automatic responses.* It was found that patients with Parkinson's disease were impaired in learning a visually cued operant conditioning task, while patients with Huntington's disease failed to learn a sequence of button presses.

Patient HM

Severe anterograde amnesia follows bilateral damage to the hippocampus Patient HM suffered from severe epilepsy following a bicycle accident at age 7 -To minimize his epilepsy, his surgeon's removed his medial temporal lobe (including the hippocampus) at the age of 27 -Severe anterograde amnesia HM exhibited: -Normal Short-Term & Normal Long Term for events prior to the surgery -Normal perceptual learning -Normal sensory-response learning -Normal motor learning HM's problem was transfer from STM to LTM

Panic Attack Symptoms

Shortness of breath clammy sweat irregularities in heartbeat dizziness faintness feelings of unreality Occurs in 1-2% of population -Has an early onset Symptoms are similar across cultures The person experiencing a panic attack often feels that they are going to die and often seeks help in a hospital emergency room. Anticipatory anxiety leads to Agoraphobia: fear of panic attack in public places

What starts a meal?

Signals from the stomach -Recently, researchers discovered a hormonal signal that may underlie communication with the brain -The gastrointestinal system (especially the stomach) releases a peptide hormone called ghrelin

feeding termination

Signals related to glucose and lipid start a meal -What factors contribute to ending a meal? Head factors -Info from the receptors in the head: the nose, the eyes, the tongue and the throat -Sham-feeding studies suggest minimal impact of head factors on ending a meal -Taste factors allow for learning about the caloric content of different foods and can adjust subsequent intake

SAD (seasonal affective disorder)

Some people become depressed during the winter season, when days are short and nights are long Appears to have a genetic basis: one factor is a particular allele of the gene responsible for the production of melanopsin Treated with phototherapy; increased exposure to light improves mood in SAD Incidence is 4 women to 1 male Involves; -Mood and sleep disturbances -Carbohydrate cravings and weight gain

Neural Model of Operant Conditioning

Stimulus --> Neural circuit that detects a particular stimulus --> Neural circuit that controls a particular behavior --> Behavior --> Reinforcing stimulus --> Reinforcement System --> Reinforcement System strengthens connection between Perceptual and Motor Systems

Types of learning

Stimulus-response: Making a response when a particular stimulus is present -Classical -Operant Motor: Involves forming new circuits in motor system Perceptual: learning functions to identify objects and situation Relational: Involves identifying connections between stimuli

Neurogenesis and Depression

Stress and depression are associated with reduced hippocampal neurogenesis Antidepressant treatment increases hippocampal neurogenesis in lab animals Evidence that exercise induces neurogenesis in the human brain

DA activity in schizophrenia

Studies of dopamine receptors in the schizophrenic brain have provided mixed results Postmortem studies suggest increased #'s of D2 receptors in striatum (may be due to exposure of antipsychotic drugs) -Striatum is motor control area: may be the wrong site -Schizo may involve D3 or D4 receptors Clozapine is an effective antipsychotic drug that does not interact with D2 receptors -Cloza acts on D4 receptors in the n. accumbens

Electrical stimulation of rat brain

Study found that stimulation induces reinforcement -This is supported by electrodes placed along the mesolimbic DA pathway- subjects will perform

Cortical areas of movement

Supplementary motor area: involved in performing previously learned, automatic series of behaviors Premotor cortex: involved in motor learning and memory that is guided by sensory info Ventral premotor cortex:home to mirror neurons that facilitate motor learning when observing another individual

RYGB Treatment

Suzuki found that rats that sustained a RYGB procedure(but not rats that recieved sham sugery) ate less, lost weight, and showed decreased glucose levels

Phases of LTP

Synaptic and more global cellular processes work together to result in: -A way to add specificity to use-dependent synaptic plasticity -Cell wide allocation of modified synaptic information

nigrostriatal system

System that projects from the substantia nigra to the caudate nucleus and putamen Controls movement

stimulus-response learning

The ability to learn to perform a particular behavior when a particular stimulus is present. Establishes connections between circuits involved in perception and those involved in movement- could be an automatic response such as a defensive reflex, or a complicated sequence of movements Includes two major categories of learning that psychologists have studied extensively: classical conditioning and operant conditioning.

LTP and NMDA

The activation of NMDA receptors is necessary for the first step in the process of events that establishes LTP: the entry of calcium ions into dendritic spines. backwash of depolarization across the cell body triggers a dendritic spike, meaning that all of its dendritic spines become depolarized for a brief time when the axon of a pyramidal cell fires. If dendritic spikes are blocked by the administration of a toxin (tetrodotoxin), LTP does not occur If the activity of strong synapses located elsewhere on the postsynaptic cell has caused the cell to fire, then a dendritic spike will depolarize the postsynaptic membrane enough to eject the magnesium ions from the calcium channels of the NMDA receptors in the dendritic spines.

Benzodiazepines

The amygdala contains a high concentration of GABA-A receptors, which are the target of the benzodiazepines Bezo is an anxiolytic- they reduce anxiety GABA acts via GABA A and GABA B to produce IPSPs Benzo agonists increase sensitivity of GABA A receptors and decrease anxiety Administration of a benzodiazepine (lorazepam) decreased the activation of both the amygdala and the insula of participants looking at emotional faces. Administration of flumazenil, a benzodiazepine antagonist (having an action opposite that of benzodiazepines), produces panic in patients with panic disorder but not in control participants

glucose and glycogen

The body uses either glucose or fatty acids for energy The brain can use only glucose Thus brain requires constant supply of glucose (which it can use without insulin) Body can make use of glucose only in the presence of insulin In the absence of insulin, the body uses fatty acids for an energy source Glucose -(insulin)-> glycogen --> fat --> Fatty acid

AMPA and LTP

The establishment of LTP first caused movement of AMPA receptors into the postsynaptic membranes of dendritic spines from adjacent nonsynaptic regions of the dendrites. Several minutes later, AMPA receptors were carried from the interior of the cell to the dendritic shaft, where they replaced the AMPA receptors that had been inserted in the postsynaptic membrane of the spines

Obesity

The excessive accumulation of fat -BMI: weight (kg)/height(m)^2 -BMI>30 obesity (~27% of population in USA); BMI>25 overweight (~30% of population in USA) -Incidence of obesity is increasing -Obesity is hazardous to health (diabetes, hypertension) Widespread issue that has medical consequences In the US, about 67% of men and 62% of women are overweight, defined as a BMI index for over 25 Obesity is increasing in developing countries as household incomes rise Ex: over a 10 year period the incidence of obesity in young urban children in China increases by a factor of eight

Iproniazid

The first antidepressant drug a monoamine oxidase inhibitor MAO destroys excess monoamine transmitter substances within terminal buttons. In this way, iproniazid increases dopamine, norepinephrine, and serotonin in the synapse

Signals from the stomach

The gastrointestinal system (especially the stomach) releases a peptide hormone called ghrelin when the digestive tract is empty. In humans, blood levels of ghrelin increase shortly before each meal, which suggests that this peptide is involved in the initiation of a meal. The entry of food into the upper part of the small intestine—the duodenum—suppresses ghrelin secretion Hypoglycemia: Lack of glucose or unable to metabolize glucose By stimulating hypoglycemia in the body, we can cause glucoprivation, which stimulates eating Hunger can also be produced by causing lipoprivation—depriving cells of lipids *Glucoprivic and lipoprivic hunger appears to be stimulated by receptors in the liver, so cutting these connections can rid the body of these hunger urges*

Milner's conclusions

The hippocampus is not the location of long-term memories; nor is it necessary for the retrieval of long-term memories The hippocampus is not the location of immediate (short-term) memories The hippocampus is involved in converting immediate (short-term) memories into long-term memories

basal ganglia and OCD

The investigators found antibodies to type A β-hemolytic streptococcus, and MRI scans indicated abnormalities in the basal ganglia. An MRI study of thirty-four children with streptococcus-associated tics or OCD by Giedd et al. (2000) found an increase in the size of the basal ganglia that they attributed to an autoimmune inflammation of this region.

Amygdala in Classical Conditioning

The lateral nucleus of the amygdala contains neurons whose axons project to the central nucleus. --> Terminal buttons from neurons that transmit auditory and somatosensory information to the lateral nucleus form synapses with dendritic spines on these neurons. --> When an individual encounters a painful stimulus, somatosensory input activates strong synapses in the lateral nucleus. --> As a result, the neurons in this nucleus begin firing, which activates neurons in the central nucleus, evoking an unlearned (unconditioned) emotional response--> If an unconditioned stimulus (in our example, the fence) is paired with the painful stimulus, the weak synapses in the lateral amygdala are strengthened. --> The synaptic changes responsible for this type of learning take place within this circuit.

Prader-Willi Syndrome

The leading genetic cause of obesity. The degree of mental retardation varies, but is usually in the mild range. It can result in low muscle tone, short stature, incomplete sexual development, cognitive disabilities, problem behaviors, and a chronic feeling of hunger that can lead to excessive eating and life-threatening obesity.

Reinforcement

The mesolimbic system of dopaminergic neurons begins in the ventral tegmental area (VTA) of the midbrain and projects rostrally to several forebrain regions, including the amygdala, hippocampus, and nucleus accumbens (NAC). Neurons in the NAC project to the ventral part of the basal ganglia, which are involved in learning. The mesocortical system also plays a role in reinforcement. This system also begins in the ventral tegmental area but projects to the prefrontal cortex, the limbic cortex, and the hippocampus. Because stimulating several regions of the brain is reinforcing, the mesolimbic system is only one of several reinforcement pathways. Release of dopamine in a variety of brain locations affects learning in a variety of tasks and that dopamine plays a critical role in long-lasting long-term changes in many brain regions, including the basal ganglia, amygdala, and frontal cortex

fasting phase (cont)

The most important controlling factor for the fasting phase is a low level of insulin and a high level of glucagon The islet cells of the pancreas produce both insulin and glucagon Glucagon is secreted when blood-glucose levels fall-promotes mobilization of nutrient -Causes liver to convert glycogen to glucose -promotes breakdown of fats

Steps of basal ganglia pathway

The neostriatum—the caudate nucleus and the putamen—receives sensory information from all regions of the cerebral cortex--> It also receives information from the frontal lobes about movements that are planned or are actually in progress --> The outputs of the caudate nucleus and the putamen are sent to another part of the basal ganglia: the globus pallidus. --> The outputs of this structure are sent to the frontal cortex: to the premotor and supplementary motor cortex, where plans for movements are made, and to the primary motor cortex, where they are executed.

Prefrontal Cortex (Reinforcement)

The prefrontal cortex provides an important input to the ventral tegmental area. -The terminal buttons of the axons connecting these two areas secrete glutamate, and the activity of these synapses makes dopaminergic neurons in the ventral tegmental area fire in a bursting pattern, which greatly increases the amount of dopamine they secrete in the nucleus accumbens Generally involved in devising strategies, making plans, evaluating progress made toward goals, and judging the appropriateness of one's own behavior. Turns on the reinforcement mechanism when it determines that the ongoing behavior is bringing the organism nearer to its goals and that the present strategy is working.

long-term potentiation (LTP) pathway

The primary input to the hippocampal formation comes from the entorhinal cortex. The axons of neurons in the entorhinal cortex pass through the perforant path and form synapses with the granule cells of the dentate gyrus. Cells in the dentate gyrus send projections to a region of the hippocampus called CA3 (also called the mossy fiber pathway). The CA3 neurons then synapse with cells in the CA1 region (also called the Schaffer collateral pathway). The CA1 neurons project back to the entorhinal cortex to make a loop.

Disordered Sleep

The sleep of people with depression tends to show reduced slow-wave sleep, and increased stage 1 sleep. -Reduced REM latency, reduced stages 3 & 4 sleep -People wake up more frequently and struggle getting back to sleep REM deprivation improves mood Antidepressant drugs suppress REM sleep and increase SW sleep REM sleep deprivation is more effective than is total sleep deprivation Sleep is fragmented in depression and people tend to awaken frequently, especially toward the morning. In addition, REM sleep occurs earlier, the first half of the night contains a higher proportion of REM periods, and REM sleep contains an increased number of rapid eye movements

Why does treating depressive symptoms link with decreased activity in the subgenual ACC?

The subgenual ACC is reciprocally connected with several regions of the prefrontal cortex. It is also connected with the amygdala, hippocampus, and nucleus accumbens. Successful treatment of the symptoms of depression may result in decreased activity of the amygdala through direct connections between these two structures and through indirect connections via the prefrontal cortex.

Anticipatory satiety signals

These factors predict that the food in the digestive system will, when absorbed, eventually restore the system variables that cause hunger. Not until nutrients are absorbed from the intestines can they be used to nourish the cells of the body and replenish the body's nutrient reservoirs.

Hypovolemic thirst

Thirst that occurs when the volume of the blood plasma—the intravascular volume—decreases. Can be caused by: -blood loss -vomiting -diarrhea -Experimental techniques *Injection of a colloid such as PG *PG sequesters water and salt; then withdrawn from the body In addition, because hypovolemia involves a loss of sodium as well as water, hypovolemic thirst leads to a salt appetite and drinking.

Group A B-hemolytic streptococci (GABHS)

This infection can trigger several autoimmune diseases, in which the patient's immune system attacks and damages certain tissues of the body, including the valves of the heart, the kidneys, and—in this case—parts of the brain

long-term memory

This memory stage is relatively permanent and can last for minutes, hours, days, or decades. Information that will be retained from short-term memory is consolidated into long-term memory, but not all info information from short-term memory makes it to long-term memory. Long-term memories can be retrieved throughout a lifetime and strengthened with increased retrieval

RYGB (Roux-en-Y gastric bypass)

This procedure produces a small pouch in the upper end of the stomach. However, the stomach pouch is attached to a lower portion of the intestine. The effect is to produce a small stomach whose contents enter the jejunum (second portion of the small intestine), bypassing the duodenum (first portion of the small intestine). Digestive enzymes that are secreted into the duodenum pass through the upper intestine and meet up with the meal that has just been received from the stomach pouch. Disrupts the secretion of ghrelin and increases blood levels of PYY, which reduces hunger and increases satiety

adipose tissue

Tissue that stores fat. Consists of cells that are capable of absorbing nutrients from the blood, converting them to triglycerides, and storing them. These cells can expand in size. The size of the fat cells is determined by the amount of triglycerides the cells contain.

Functions of the Reinforcement System

To detect the presence of a reinforcing stimulus (that is, recognize that something good has just happened) Strengthen the connections between the neurons that detect the specific stimulus (such as the sight of a lever) and the neurons that produce the response (a lever press) Occurs when neural circuits detect a reinforcing stimulus and activate dopaminergic neurons in the ventral tegmental area Not automatic; may depend on physiological state

Liver factors (Satiety)

Tordoff and Friedman (1988) infused small amounts of two nutrients, glucose and fructose, into the hepatic portal vein. Results strongly suggest that when the liver receives nutrients from the intestines, it sends a signal to the brain that produces satiety. More accurately, the signal continues the satiety that was already started by signals arising from the stomach and upper intestine.

Stimulus and Response Pathways

Transcortical Pathways Basal Ganglia and Thalamic Pathways

Transcortical Pathways

Transcortical connections are involved in acquiring episodic memories—complex perceptual memories of sequences of events that we witness or that are described to us. Also involved in acquiring complex behaviors that involve deliberation or instruction- A memorized set of rules (or an instructor sitting next to us) provides a script for us to follow. Practice allows the behavior becomes much more fluid

monochorionic

Twins with one shared placenta

Insulin secretion

Two factors stimulate secretion: -Presence of glucose in the blood directly stimulates the islet cells in the pancreas -Activity of parasympathetic axons that innervate the pancreas *Happens as a result of reflexes initiated by eating Under the influence of insulin, cells take up glucose and blood levels drop temporarily

postpartum depression (PPD)

Type of PPD can happen a few days after or months after birth, regardless of which child -Feelings similar, but stronger, to the baby blues- sadness, despair, anxiety, irritability -Keeps a woman from doing the things she needs to do every day -If a woman does not get treatment, symptoms can get worse and last for a year -While PPD is a serious condition, it can be treated with medication and counseling

Baby Blues

Type of PPD that happens days after childbirth -Moodswings- Very happy --> Very sad -Crying for no reason and feeling impatient -May last a few hours or as long as 1-2 weeks -Don't always require treatment from a healthcare provider

Neuroleptics

Typical antipsychotics -Chlorpromazine (D2 receptors) Atypical antipsychotics -Clozapine (D4, D1, D3 receptors)

classical eyeblink conditioning

US = Air puff UR = blink of the eye CS = tone from the speakers CR = Tone elicits a blink Connection between two stimuli is made

Developing Anxiety Disorders

Variations in the gene that encodes production of the brain derived neurotrophic factor (BDNF) protein may play a role in anxiety disorders amygdala and the cingulate, prefrontal, and insular cortices are involved in anxiety disorders optogenetic stimulation of the terminals of neurons of the basolateral nucleus of the amygdala, that formed synapses with neurons in the central nucleus, caused an immediate termination of anxious behavior in mice

MDD symptoms

Very little energy, and move and talk slowly May pace around restlessly and aimlessly. They may cry a lot or be unable to experience pleasure and lose their appetite for food and sex. Their sleep may be disturbed. People with depression often have difficulty falling asleep and awaken early and find it difficult to get to sleep again. Even body functions can become depressed. People with depression often become constipated, and their secretion of saliva decreases. Severely depressed people may feel extremely unworthy and have strong feelings of guilt.

Visual Short-Term Memory

Visual STM is indexed by delayed matching-to-sample tasks Visual STM depends on visual association cortex and on prefrontal cortex

Vitamin D Deficiency

Vitamin D is a fat-soluble chemical that is produced in the skin by the action of ultraviolet rays on a chemical derived from cholesterol. One study found that taking a vitamin D supplement during the first year of a child's life was associated with reduced incidence of schizophrenia among boys

Water intake

Water intake is linked to temp regulation and food intake -Sweating--> Depletion of body's water supplies--> Thirst -Eating salty food --> Affect water levels--> Thirst -Eating any meal is dehydrating -Drinking cold water--> heat loss

feeding initiation

What gets us to start eating is different from what gets us to stop Environmental factors to start: -Habit *Meal schedule can dictate the inter-meal interval *We can adjust meal size, less so -inter-meal interval -Conditioned environmental cues (conditioned eating) -Stimuli in the environment *A clock (breakfast at 8, lunch at noon, dinner at 6 pm) *Sight/smell of food *Presence of other people +Meal size goes up with group size

Evaporation and thirst

When we lose water through evaporation, we lose it from all three fluid compartments: intracellular, interstitial, and intravascular. This means that evaporation produces both volumetric thirst and osmometric thirst.

intracellular fluid

Where two-thirds of the body's water is contained Fluid portion of cytoplasm of cells Losing intracellular water deprives cells of the ability to perform many chemical reactions, and gaining water can cause their membranes to rupture.

Tardive dyskinesia

Whereas patients with Parkinson's disease lose dopamine-releasing cells in the substantia nigra and have difficulty moving, patients with tardive dyskinesia are unable to stop moving. Dyskinesia also commonly occurs when patients with Parkinson's disease receive too much l-DOPA

Korsakoff's syndrome

a disease that afflicts long-term alcoholics, leaving some abilities intact but including hallucinations and a tendency to repeat the same story Severe form of anterograde amnesia- Thiamine deficiency produces brain damage Symptoms: -Severe retrograde and anterograde amnesia -Confabulation Mammillary body degeneration (connects thalamus and hippocampus)

Trichotillomania

a disorder characterized by the repeated pulling out of one's own hair treated by clomipramine

lipoprivation

a dramatic fall in the level of fatty acids available to cells; usually caused by drugs that inhibit fatty acid metabolism Methyl palmoxirate (MP) and mercaptoacetate (MA) induce lipoprivation by interfering with the metabolism of fatty acids stimulates eating

Glucoprivation

a dramatic fall in the level of glucose available to cells; can be caused by a fall in the blood level of glucose or by drugs that inhibit glucose metabolism 2-DG induces glucoprivation by competing with glucose for metabolism and transport into the cell 2-DG stimulates eating

AP5

a drug that blocks NMDA receptors, prevents calcium ions from entering the dendritic spines and thus blocks the establishment of LTP

Fenfluramine

a drug that stimulates the release of 5-HT Used to treat obesity

anticipatory anxiety

a fear of having a panic attack; may lead to the development of agoraphobia

ventral tegmental area (VTA)

a group of dopaminergic neurons in the ventral midbrain whose axons form the mesolimbic and mesocortical systems; plays a critical role in reinforcement

LTD (long term depression)

a long-lasting decrease in the effectiveness of synaptic transmission that follows certain types of low-frequency stimulation (1-10 Hz) -Blocked by AP5 in hippocampus- thus requires NMDA receptors LTD is associated with decreased number of AMPA receptors at synapse Involves dephosphorylation of AMPA receptors Best example of LTD- in cerebellar cortex, generated by low-frequency stimulation of parallel fibers and climbing fibers, decrease firing of Purkinje neurons, as a result- increase firing of deep cerebellar nuclei neurons

echoic memory

a momentary sensory memory of auditory stimuli; if attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds

BDNF (brain-derived neurotrophic factor)

a neurotrophin similar to nerve growth factor that regulates neuronal survival and differentiation during development, and is associated with anxiety and depression

arcuate nucleus

a nucleus in the base of the hypothalamus that controls secretions of the anterior pituitary gland; contains NPY-secreting neurons involved in feeding and control of metabolism Contains two other systems of peptide-secreting neurons, both of which serve as anorexigens ("appetite-suppressing chemicals"): -CART: Injection of CART into their cerebral ventricles inhibits feeding, including the feeding stimulated by NPY, whereas infusion of a CART antibody, which destroys molecules of CART, increases feeding -a-MSH: Whereas AgRP binds with MC4Rs and causes feeding, α-MSH binds with MC4Rs and inhibits eating

nucleus accumbens

a nucleus of the basal forebrain near the septum; receives dopamine-secreting terminal buttons from neurons of the ventral tegmental area and is thought to be involved in reinforcement and attention Deep brain stimulation has been found to reduce the symptoms of depression in 50% of treatment resistant patients Extracellular levels of DA within the nucleus accumbens are increase in a male rat during a sexual encounter with a female rat

Ghrelin

a peptide hormone released by the stomach that increases eating; also produced by neurons in the brain stimulates thoughts about food. Possible cause of Prader-Willi syndrome (overeating) is chronic elevation in the blood level of ghrelin—a level that remains high even after a meal Even though the stomach secretes ghrelin, the secretion of this hormone appears to be controlled by receptors in the upper part of the small intestine, not in the stomach itself. Blood levels of this peptide increase with fasting and are reduced after a meal- involved in initiation of meal

Angiotensin

a peptide hormone that constricts blood vessels, causes the retention of sodium and water, and produces thirst and a salt appetite

social anxiety disorder

a persistent, excessive fear of being exposed to the scrutiny of other people that leads people to avoid social situations that involve speaking or performing in public. If such situations are unavoidable, the person experiences intense anxiety and distress. The prevalence of social anxiety disorder is almost equally likely in men and women In the United States, non-Hispanic Caucasian individuals experience higher rates of social anxiety disorder than persons of other descents can be effectively treated with drugs that increase activity in the serotonin system

negative feedback

a process whereby the effect produced by an action serves to diminish or terminate the action. Ex: The rise in room temperature can cause the thermostat to turn the heater off. Because the activity of the correctional mechanism (heat production) feeds back to the thermostat and causes it to turn the heater off, this process is called negative feedback.

Hebbian synapse

a synapse that is strengthened when it successfully drives the postsynaptic cell

Mesocortical system

a system of dopaminergic neurons originating in the ventral tegmental area and terminating in the prefrontal cortex Short term memory/ planning/ problem soliving

Phototherapy

a therapy that involves repeated exposure to bright light for several hours a day- Light serves as a zeitgeber A one-hour walk outside each morning has also been found to reduce the symptoms of SAD

Developmental changes (schizo)

abnormalities in the striatal dopaminergic system may constitute the primary cause of the process that leads to schizophrenia

OCD

an anxiety disorder characterized by unwanted repetitive thoughts (obsessions) and/or actions (compulsions) Most compulsions fall into one of four categories: counting, checking, cleaning, and avoidance. individuals with obsessive-compulsive disorder recognize that their thoughts and behaviors are irrational compulsive behaviors seen in OCD are forms of species-typical behaviors—for example, grooming, cleaning, and attention to sources of potential danger—that are released from normal control mechanisms by a brain dysfunction incidence is 1-2%

SFO (subfornical organ)

an area of the brain located near the junction of the two lateral ventricles that regulates drinking site of action for angiotensin II -Infusion of AII into SFO elicit drinking -Lesions of SFO abolish drinking to AII -SFO projects to the median preoptic nucleus

entorhinal cortex

an area of the medial temporal cortex that is a major source of neural signals to the hippocampus

Aripiprazole

an atypical antipsychotic drug that acts as a partial agonist at dopamine receptors This means that in a patient with schizophrenia, aripiprazole serves as an antagonist in the mesolimbic system, where too much dopamine is present, but serves as an agonist in regions such as the prefrontal cortex, where too little dopamine is present.

PCP (phencyclidine)

an indirect antagonist of glutamate NMDA receptors. (So is ketamine.); Produces positive and negative symptoms of schizo -Negative: related to decreased metabolic activity in prefrontal cortex following PCP treatment -Positive: related to indirect actions of PCP on n. accumbens DA By inhibiting the activity of NMDA receptors and dopamine receptors, PCP causes hypofrontality, which appears to be the primary cause of negative and cognitive symptoms.

AV3V

anteroventral tip of the third ventricle May contain the osmoreceptors responsible for osmometric thirst -NaCl infused into the Av3V produces drinking -Damage to the region near the Av3v in humans produces lack of thirst Contains the lamina terminalis Contains two circumventricular organs -OVLT -SFO

Clozapine

atypical antipsychotic; blocks D4 receptors in the nucleus accumbens

short term reservoir

cells of liver and muscles that store glycogen to sustain our fuel needs Glucose is stimulated to do so by the presence of insulin, but pancreas instead creates glucagon when reserves of glucose gets too low Glucose -(Insulin)-> Glycogen- with stable levels of glucose Glycogen -(glucagon)-> Glucose- when glucose levels fall

Border cells

cells that fire when an animal is near one or more boundaries of the environment, such as the walls of a box

head direction cells

cells that simply fire when the animal's head is facing a particular direction with respect to the distant cues in a particular environment. As the animal turns, different cells will fire according to the direction in which the animal is looking. These cells do not reflect the animal's location in the environment, only the direction of its head.

Effects of Dopamine Antagonists

chlorpromazine (CPZ) was found to dramatically reduce the positive symptoms of schizophrenia -Henri Laborit- French surgeon discovered that CPZ had a calming effect on schizo -Effect: elimination or diminished hallucinations and delusions -*CPZ blocks DA/D2 receptors* other drugs have been developed that reduce the positive symptoms of schizophrenia. These drugs are dopamine antagonists that block D2 and D3 dopamine receptors

OCD treatments

clomipramine fluoxetine fluvoxamine These drugs alleviate the symptoms of obsessive-compulsive disorder by reducing the strength of innate tendencies for counting, checking, cleaning, and avoidance behaviors that may underlie this disorder DEEP BRAIN STIMULATION of the subthalamic nucleus reduces OCD symptoms

CART

cocaine- and amphetamine-regulated transcript CART neurons appear to play an important role in satiety. If animals are deprived of food, levels of CART decrease. Neurons release a-MSH, a second anorexigen

Supersensitivity

compensatory mechanism in which some types of receptors become more sensitive if they are inhibited for a period of time by a drug that blocks them. It seems that when D2 receptors in the caudate nucleus and putamen are chronically blocked by an antipsychotic drug, they become super sensitive, which in some cases overcompensates for the effects of the drug, causing the neurological symptoms to occur.

Neurogenesis

creation of new neurons in the adult brain Several studies with laboratory animals have shown that stressful experiences that produce the symptoms of depression suppress hippocampal neurogenesis, and the administration of antidepressant treatments, including MAO inhibitors, tricyclic antidepressants, SSRIs, ECT, and lithium, increases neurogenesis. Moreover, if neurogenesis is suppressed by a low-level dose of X-radiation, antidepressant drugs lose their effectiveness. Histological procedures verified that increased neurogenesis in the mouse brain correlated with the increased blood volume, which strongly supports the conclusion that exercise induces neurogenesis in the human brain, as well.

hypofrontality

decreased activity of the frontal lobes—in particular, of the dorsolateral prefrontal cortex (dlPFC) -Damage to prefrontal cortex impairs behavioral flexibility -Schizos show decreased activity in the prefrontal cortex Hypofrontality in the dlPFC that is responsible for negative symptoms may also be related to hyperactivity in the mesolimbic pathways that is responsible for positive symptoms. In hypofrontality, control over the mesolimbic pathway is disinhibited, contributing to increased activity (and positive symptoms) arising from this region.

semantic dimentia

disease where semantic information is lost, but episodic memory for recent events can be spared TMS of the left anterior temporal lobe, which disrupts the normal neural activity of this region, produced the symptoms of semantic dementia

atypical antipsychotics

drugs that increase dopaminergic activity in the prefrontal cortex and reduce it in the mesolimbic system means that in a patient with schizophrenia, aripiprazole serves as an antagonist in the mesolimbic system, where too much dopamine is present, but serves as an agonist in regions such as the prefrontal cortex, where too little dopamine is present

onychophagia

eating the nails (nail biting) treated by clomipramine

panic disorder

episodic attacks of acute anxiety—periods of intense and unremitting terror that range from a few seconds to a few hours Anxiety about an anxiety attack Women are approximately twice as likely as men to experience panic disorder, and this difference emerges in early adolescence

extracellular fluid

fluid outside the cell Includes: -Intravascular fluid: blood plasma -Cerebrospinal fluid -Interstitial Fluid: Fluid that bathes our cell The volume of intravascular fluid must be closely regulated, as the heart can no longer pump the blood effectively if the volume is too low

Synaptogenesis

formation of new synaptic connections (historical misconception that brains are hard-wired) Experience-induced changes in synapses in adult animals -Learning of various types can change the number and configuration of synaptic connections in brain regions involved in learned behaviors +Complex environment housing- visual cortex, hippocampus, cerebellum, striatum

Hippocampus and spatial learning

hippocampal lesions disrupt the ability to keep track of and remember spatial locations The fact that neurons in the hippocampal formation have spatial receptive fields means that this information is represented by patterns of activity in circuits of large numbers of neurons within the hippocampal formation The hippocampus appears to receive its spatial information from the parietal lobes by means of the entorhinal cortex.

Anhedonia

inability to experience pleasure a negative symptom of schizophrenia

Diabetes mellitus (type 1)

insulin is functionally absent due to destruction of beta cells of pancreas; where insulin would normally be produced. starts in children ages 4 or older, adolescense. symptoms include polyuria, polydipsia, polyphagia, nausea, weight loss, fatigue, blurred vision, and dehydration

agoraphobia

intense fear or anxiety about leaving home, being in open spaces, or being in enclosed spaces or in lines or crowds. People with agoraphobia may avoid these situations and experience fear or anxiety about these situations that is out of proportion to the actual threat or danger they pose.

perforant pathway

interconnects the entorhinal cortex with the granule cells of the dentate gyrus.

DISC1 gene

involved in regulation of embryonic and adult neurogenesis, neuronal migration during embryonic development, function of the postsynaptic density in excitatory neurons, and function of mitochondria DISC1 variants may increase the probability of developing schizophrenia.

Relational Learning

learning the relationships among individual stimuli. For example, consider what we must learn to become familiar with the contents of a room: -First, we must learn to recognize each of the objects. -We also must learn the relative locations of the objects with respect to each other. -As a result, when we find ourselves located in a particular place in the room, our perceptions of these objects and their locations relative to us tell us exactly where we are.

STM capacity

limited capacity: 7 items Brief duration Can be lost without rehearsal

Biological treatments (Bipolar)

lithium some anticonvulsant or antipsychotic drugs. Furthermore, the fact that lithium is effective in treating bipolar affective disorder but not major depressive disorder suggests that there is a fundamental, biological difference between these two disorders

types of affective disorders

major depressive disorder -depression may be continuous and unremitting or, more typically, may come in episodes -15.9 percent of people with MDD attempt to commit suicide bipolar disorder -Episodes of mania can last from a few days to several months -29.2 percent of people with bipolar disorder attempt to commit suicide

Biological Treatments (MDD)

monoamine oxidase (MAO) inhibitors drugs that inhibit the reuptake of norepinephrine or serotonin or interfere with NMDA receptors electroconvulsive therapy transcranial magnetic stimulation -Applied to prefrontal cortex -Response rate of ~30% deep brain stimulation vagus nerve stimulation -80% fibers are afferents -Low side effects -Used for treatment-resistant depression bright-light therapy (phototherapy) sleep deprivation.

Dichorionic

multiple pregnancy with two placentas

osmoreceptors

neurons whose firing rate is affected by their level of hydration located in the lamina terminalis Are in the brain -Infusions of NaCl into the brain induce thirst

categories of long-term memory

nondeclarative: memories that we are not necessarily conscious of declarative: memory of events and facts that we can think and talk about -Includes episodic and semantic memories

Types of thirst

osmometric thirst: Increase in osmotic pressure volumetric thirst: Measuring of the volume of the blood plasma

anterograde amnesia

people with anterograde amnesia cannot form declarative memories that they have had since the time of their brain damage. When patients are appropriately trained and tested, we find that they are capable of three of the four major types of learning: -perceptual learning: Patients could better retain broken drawings -stimulus-response learning: Patient was successfully trained on an operant conditioning task—a visual discrimination task in which pennies were given for correct responses. -motor learning: patients could learn a sequence of button presses in a serial reaction time task; It is clear that their rate increased because they learned the sequence; if the sequence changed, their performance decreased

Parts of hippocampal region

place cells grid cells head direction cells border cells The information provided by all of these cells reflects the animal's location and head direction, and this information is available to other regions of the brain.

CCK

produced by the small intestine when you eat and tells brain you're full, suppressing appetite In addition to stimulating contraction of the gallbladder, CCK causes the pylorus to constrict and inhibits gastric contractions, keeping the stomach from giving the duodenum more food. CCK acts on receptors located in the junction between the stomach and the duodenum Acts peripherally to reduce eating: vagotomy prevents the action of CCK to reduce eating CCK antagonists increase feeding CCK doesn't cross the blood-brain barrier, so the place of action- outside the CNS or in one of the circumventricular organs

Donald Hebb

proposed that human learning takes place by neurons forming new connections with one another or by the strengthening of connections that already exist Implies that repeated neural activity will produce physical changes in the nervous system Hebbian synapses- those which are enhanced by coincident activity between pre- and postsynaptic neuron

Leptin

protein hormone secreted by fat cells; when abundant, causes brain to increase metabolism and decrease hunger Activating leptin receptors on NPY/AgRP-secreting neurons in the arcuate nucleus inhibits these neurons . Also decreases the sensitivity of gustatory sweet receptors to the taste of sucrose and saccharine High levels of leptin stimulate the release of the anorexigens CART and α-MSH and inhibit the release of the orexigens NPY and AgRP. Low levels of leptin have just the opposite effects: the anorexigenic CART/α-MSH neurons are not activated and the orexigenic NPY/AgRP neurons are not inhibited

Histones

protein molecules around which DNA is tightly coiled in chromatin When methyl groups (-CH3)(-CH3) attach to histone proteins, the regions of DNA wound around them draw in more tightly, which prevents these regions from being translated into messenger RNA. Methylation of histone proteins prevents the expression of particular genes

subgenual ACC

region of the medial prefrontal cortex located below the "knee" at the front of the corpus callosum deep brain stimulation targeted at the subgenual ACC has been found to provide relief of depressive symptoms

Motor Cortex

responsible for controlling movements of the body Several adjacent areas of cortex are critical in organizing complex, learned movements Improvement in motor learning occurs in between learning sessions and following sleep

Mania symptoms

sense of unjustified euphoria or irritable mood Must last a week Quickly change from topic to topic and often have delusions, but they lack the severe thought disorganization that is seen in schizophrenia. Usually exhibit nonstop speech and motor activity, and grandiosity. decreased need for sleep People experiencing mania can be full of their own importance and become irritable, angry, or defensive if they are contradicted. Go for long periods without sleep, working furiously on projects that are often unrealistic, or engaging in other increased, goal-directed behaviors.

Memory Process

sensory information enters short-term memory rehearsal keeps it there the information makes its way into long-term memory, where it is permanently stored

Types of relational learning

spatial episodic observational

Fatty acids

stearic acid oleic acid palmitic acid

spatial strategy

strategy describing the arrangement of space related to an event, place, or object Activates hippocampus

bariatric surgery

surgical approach to extreme obesity, usually accomplished by stapling the stomach to create a small stomach pouch or bypassing the stomach through gastric bypass surgery Aimed at the stomach, small intestine, or both

Development of Schizophrenia

symptoms of depression --> social withdrawal or impairment (negative symptoms) and cognitive difficulties (cognitive symptoms) --> positive symptoms

LTP (long term potentiation)

synaptic changes in the glutamate system that serve to increase the excitatory postsynaptic potentials (EPSPs) to the postsynaptic cells in the amygdala increases the learning experience and play a critical role in conditioned emotional responses *stimulation of the synapses and the depolarization of the neuron must occur together*

Thirst

tendency to seek water and to ingest it Issues to consider: -Stimuli for thirst? *Cellular dehydration *Volume changes -Hormonal involvement in thirst -Neural circuits that mediate thirst

declarative memory

the cognitive information retrieved from explicit memory; knowledge that can be declared Can be verbally expressed Two types: -Episodic: include information about when and under what conditions a particular episode occurred and the order in which the events in the episode took place -Semantic: involve facts, but they do not include information about the context in which the facts were learned.

glutamate hypothesis

the hypothesis that schizophrenia may be caused, in part, by understimulation of glutamate receptors

dopamine hypothesis

the idea that positive symptoms of schizophrenia involves an excess of dopamine activity PET studies indicate greater release of dopamine in the striatum of schizos to a test dose of amphetamine AMOUNT OF DOPAMINE RELEASED WAS RELATED TO INCREASE IN POSITIVE SYMPTOMS

seasonality effect

the increased incidence of schizophrenia in people born during late winter and early spring -Occurs in cities, but not the countryside May be related to the mother contracting a viral infection during the second trimester of fetal development

set point

the optimal value of the system variable in a regulatory mechanism Ex: Heater can be adjusted so that contacts of a switch will be closed when the temperature falls below a preset value

therapeutic lag

the period of time between beginning an antidepressant treatment and experiencing therapeutic effects, usually several weeks In response to several weeks of elevated levels of neurotransmitter (particularly 5-HT), presynaptic autoreceptors desensitize and become less sensitive to the neurotransmitter. This further enhances the amount of neurotransmitter present in the synapse, amplifying the message to postsynaptic receptors.

Confabulation

the unintended false recollection of episodic memories- fictitious memories Symptom of Korsakoff's Syndrome

osmometric thirst

thirst produced by an increase in the osmotic pressure of the interstitial fluid relative to the intracellular fluid, thus producing cellular dehydration -Loss of fluid during evaporation -Ingestion of salt increases tonicity and induces movement of water out of cells -*Volume of blood plasma does not change* Osmoreceptors change their firing rate by the interstitial fluid becoming more concentrated Pressure can alter the membrane potential

Subtypes of Schizophrenia

undifferentiated -"Wastebasket" category, various symptoms -Can be either an initial form or followed by another subtype -May be a transitional form Catatonic -Pronounced motor symptoms are apparent -Stupor and excitement (catatonic frenzy) phases -Sometimes violent, frenzied behavior Paranoid -Delusions of persecution and grandeur -Auditory hallucinations are common Disorganized -Common hallucinations -Severe disorganization -Only modest recovery is seen Also- schizoaffective disorder and schizoaffective disorder and schizophreniform disorder

Reinforcing vs Punishing Stimulus

when a behavior is followed by favorable consequences (a reinforcing stimulus), the behavior tends to occur more frequently. When a behavior is followed by unfavorable consequences (a punishing stimulus), it tends to occur less frequently.

associative long-term potentiation

when weak and strong synapses to a single neuron are stimulated at approximately the same time, the weak synapse becomes strengthened produced by the association (in time) between the activity of the two sets of synapses