Exam 4: 13,16, 17
It has been speculated that hippocampal cellular abnormalities seen in some patients with schizophrenia may have resulted from
early cell developmental problems
Injecting PYY3-36 into rats causes them to
eat less
which brain region is not one of the prominent sites of damage in Korsakoff's syndrome
hippocampus
hypertonic
if the extracellular fluid has a higher osmolarity than the cell's cytoplasm, it's said to be hypertonic to the cell, and water will move out of the cell to the region of higher solute concentration
age related impairments of memory
impairments of encoding and retrieval loss of neurons/connections problems with cholinergenic neurotransmission
Insulin Regulation of Metabolism
in addition to converting glucose into glycogen, insulin has another important function 1. Glucose transporters: to get glucose into the cell for use, glucose must be transported into the cell. Insulin acts on the transporter to serve this function, to allow glucose to enter cells of body to be used as energy Exception to this is the brain, insulin is not needed for brain cells to use insulin
Glycogenesis
is the process of converting glucose to glycogen (short term energy store), regulated by the pancreatic hormone insulin, released by beta cells in the islets of Langerhan
Two Internal Cues for Thirst
Based on the idea that the extracellular fluid (determining factor) indicates the state of the intracellular space. Hypovolemic thirst (low volume) Osmotic thirst (eat a salty meal)
LTP in area CA1 may be blocked by drugs that are _______ antagonists.
NMDA
pharmacological treatment of Tourrette's syndrome involves drugs that
antagonize dopamine
Based on studies of phencyclidine, a __ hypothesis of schizophrenia has been proposed
glutamate
Osmosensory neurons are cells that detect changes in
solute concentration found in hypothalamus
differences in the size of the hippocampus between closely related species of kangaroo rats are believed to be related to species differences in
spatial memory
angiotensin cascade
*Angiotensinogen (in blood)* Enzyme: Renin (from kidneys) *Angiotensin I* Enzyme: Converting enzyme *Angiotensin II* Enzyme: Aminopeptidase *Angiotensin III*
Why is memory important?
"Every day is alone in itself, whatever enjoyment I've had, and whatever sorrow I've had.....Right now, I'm wondering. Have I done or said anything amiss? You see, at this moment everything looks clear to me, but what happened just before? That's what worries me. It's like waking from a dream; I just don't remember" -H.M. (from Milner, 1970, pg. 37)
What is memory?
"Experiences" change our nervous system both structurally and biochemically, we refer to these changes in the nervous system as memories We assess learning by assessing changes in behavior-- behavior is an expression of learning and memory
vasopressin/ADH
(antidiuretic hormone) hormone released by posterior pituitary; raises blood pressure and enables kidneys to conserve water
Procedural memory
(implicit or nondeclarative) things you know that you can show by performance mirror tracing long term memory
Osmotic thirst
(independent of extracellular volume) more common than a loss of blood, thank goodness; triggered by a change in the concentration in extracellular fluid. Produced by: a. Loss of water in extracellular fluid: produces a change in the solute concentration (urination, perspiration) b. Intake of salt: also increases solute concentration of extracellular, causing water to be drawn out of the cells---too much and cells will be damaged c. cells in the hypothalamus serve as osmoreceptors or Osmosensory neurons in the hypothalamus (OVLT) that respond to changes in osmotic pressure.
Salt Regulation
1. Conservation of sodium, conserves water: the number of sodium ions we possess, determines how much water we can retain 2. Aldosterone is responsible for sodium conservation: a mineralcorticoid (steroid hormone) produced by the adrenal gland and works on the kidneys, causing kidneys to conserve sodium which results in water retention
Psychological evidence for synaptic modification
1. EC\IC experiments: Krech and Rosenzweig (1960's) Control: group housing 3/cage structural changes in the brain due to experience EC: groups of 10-12 in playroom, learned faster and better, recovered behavioral functions better IC: social isolate Animals spent days 25-80 in these cages 2. Cortical changes: significant increase in brain weight, attributed to an increase in cortical thickness, increase in adritic sprouting, overall increase in number of synapses, increase in synaptic contact area
discuss evidence for the effects of differential environmental experience in altering the structure and function of the nervous system
1. EC\IC experiments: Krech and Rosenzweig (1960's) Control: group housing 3/cage structural changes in the brain due to experience EC: groups of 10-12 in playroom, learned faster and better, recovered behavioral functions better IC: social isolate Animals spent days 25-80 in these cages 2. Cortical changes: significant increase in brain weight, attributed to an increase in cortical thickness, increase in adritic sprouting, overall increase in number of synapses, increase in synaptic contact area
Basal metabolism can change
1. Energy expenditure is adjusted in response to nutrition. At the start of a diet (less nutrition), the basal metabolic rate will fall to prevent losing weight. Thus, if an animal is food deprived, basal metabolism will decrease (requiring less energy to maintain your body, body is becoming more efficient) Restricted diet will have a larger affect on metabolic rate than on body weight itself. Thus, body weight is relatively constant. 2. Efficient versus inefficient and dieting
Glucose
1. Glucose is the critical sugar for the brain 2. Glucose is stored in the liver as glycogen-- Glycogen is a complex carbohydrate, made by the combining of glucose molecules, stored for a short term in the liver and muscles: short term energy store
Etiology of Schizophrenia
1. Heritability a. Incidence of schizo is 1% throughout the world - stress increases likelihood b. Twin Studies: DZ twins - 17%, MZ twins - 50-60% concordance rate average onset 18-22 years 2. Anatomical changes in the brain a. enlarged lateral (and 3rd) ventricles b. widening of the sulci - cortical degeneration c. cellular disarray in the hippocampus - disorganization d. hypofrontality - frontal lobe works at a suboptimal level
Patient R.B.: Another case of anterograde
1. History: -temporary ischemia (insufficient blood) due to cardiac arrest -lesion was restricted to hippocampus, hippocampus died 2. Outcome: -moderately severe anterograde amnesia, although less severe than H.M. -retrograde amnesia less extensive: 2 years prior
Korsakoff's's syndrome
1. History: chronic alcoholics, thiamine deficiency, lack of thiamine results in brain damage 2. Outcome: retrograde amnesia, characterized by confabulation shrunken maxillary bodies damage in dorsomedial thalamus damage to basal frontal cortex
Patient N.A.
1. History: miniature fencing foil entered nostril and pierced his left dorsal thalamus, bilateral damage to the mammillary nuclei and mammalothalamic tract 2. Outcome: Anterograde amnesia primarily for verbal material. impaired in forming declarative long term
Patient H.M.
1. History: suffered from bike accident and hit his head, severe temporal lobe epilepsy, bilateral temporal lobe-ectomy, Scoville removed medial temporal lobes, amygdala and 2/3 of hippocampus damage to entorhinal cortex, parahippocapal gyrus 2. Outcome: retrograde amnesia, immediate memory is in tact
Multiple compartment system
1. Intracellular-- fluids inside our cells, accounts for most of water in our body 2. Extracellular a. interstitial fluid: fluid between our cells b. blood plasma (the protein-rich fluid that carries red and white blood cells). 3. Movement of water: Water moves in and out of cells through aquaporins, or water channels. Diffusion is the spontaneous spread of molecules of one substance among molecules of another substance until a uniform concentration is achieved.
Antipsychotic medications and mechanisms of action
1. Mechanisms of action: BLOCK DOPAMINE RECEPTORS, direct binding antagonist a. First generation: typical antipsychotics (roughly 1/3 do not respond to treatment with atypicals - TREAT POSITIVE PSYCHOTIC SYMPTOMS) i. Class: Phenothiazines Generic name: Chlorpromazine (Thorazine) - started psychopharmacological revolution ii. Class: Butyrophenones Generic name: Haloperidol (Haldol) (higher affinity for D2 receptors) both have a high affinity and low disassociation constant for D2 receptor extrapyramidal side effects (Parkinson's like) result of blocking dopamine in substantia nigra dissociation constants: b. Second Generation: atypical antipsychotics i. Class: Dibenzoxazepines Generic name: clozapine (Clozaril) ii. Class: Benzisoxasoles Generic name: Risperidone (Risperdal) dissociation constants: The atypicals have lower affinity for D2 receptor and high dissociation constants for D2 receptor, also have a higher affinity for the serotonin 5-HT2A receptor, blocking that receptor higher affinity for D3 and D4 receptor these receptors are not found in high concentration in the caudate nucleus serotonin 2A antagonist
What are the three main dopamine pathways in the brain? How are these 3 pathways related to the positive and negative symptoms and side effects of schizophrenia? How do the pathways relate to the hypofrontality hypothesis and glutamate?
1. Nigrostriatal pathway 2. Mesolimbic 3. Mesocortical Antipsychotics block D-2 receptors in caudate nucleus --> extrapyramidal side effects Positive: 1) Negative symptoms are due to hypofrontality, frontal lobes not working at optimal level (social behavior, motivation disappears in the organism) 2) Glutamate neurons are exciting the VTA in normal individuals 3) In hypofrontality glutamate is not activated, therefore the VTA is not activated, decrease in dopamine release in the nucleus accumbens 4) When there is a lack of dopamine in the nucleus accumbens causes receptors to up regulate 5) stressor activates this system and we get psychosis due to upregulated receptors in the NA
The DA pathways and receptor subtypes
1. Nigrostriatal pathway - substantia nigra to caudate nucleus (affected in parkinsons) 2. Mesolimbic - ventraltegmental area & nucleus accumbens (reward pathway) 3.Mesocortical - VTA → prefontal cortex 5 receptors in dopamine pathways (D1-D5) D-2, drugs that have a high affinity for the D2 receptor tend to be most effective at treating schizophrenia
side effects of schizophrenia medication
1. Phenothiazines (as an example): Norepinephrine effects: blocking these results in hypotension, produces increase in heart rate (tachycardia) Histamine: blocks histamine, makes people drowsy Cholinergic effects- anticholinergic syndrome: "Blind as a bat, mad as a hatter, red as a beat, hot as a hare, dry as a bone, bloated as a toad, and the heart runs alone." Mouth and eyes dry up, pupils dilate, blurred vision, decrease in sweating, hypothermic, urinary retention) bloated Dopamine: blockade of D2 in caudate nucleus: Tardive dyskinesia - faulty movement, uncontrollable facial movements
Physical and structural changes in synapses in regards to memory
1. Physiological changes a. presynaptic: increase in transmitter release, if relatively permanent change it is considered to be a memory, increase in nerve impulses through neuromodulation b. postsynaptic: increase in number or sensitivity in the receptors (up regulation) 2. Structural changes: increase/decrease in synaptic contact area, increase in number of nerve terminals, reorganization of existing nerve terminals
what are two forms of energy reserves and how are these reserves distributed/utilized by the organisms to ensure survival
1. Processing newly ingested food: 8%-- both metabolic rate and heat production rise after eating. 2. Basal metabolism: 55% is used for maintaining body heat and other resting functions. Basal metabolism is energy used for heat production, maintenance of membrane potentials, and life-sustaining processes. 3. Active behavioral processes: 12-13% of energy, larger if more active environment (physical activity)
General conclusions from H.M., R.B. et al (revising Milner's conclusions)
1. The hippocampus is critical (and sufficient) for the consolidation of declarative memories, converting STM to LTM 2. The hippocampus is not necessary for the consolidation of procedural memories 3. The extent of the retrograde amnesia is correlated with the extent of the anterograde amnesia; both are correlated with the extent of the cortical tissue damage (entorhinal, perirhinal, parahippocampal) surrounding the hippocampus
Characteristics of the system at the cellular level (long term potentiation and memory mechanism)
1. Transmitter and receptors Transmitter= glutamate (excitatory) Receptors = NMDA receptors (n-methyl-D-aspartate) AMPA receptors found on post synaptic membrane in the hippocampus 2. Three important properties of the NMDA receptors: i. Abundant in the hippocampus ii. Ionotropic: high conductance permeable to cations: Ca2+, Na+, K+; (Ca2+ is most important) iii. Doubly gated (gated by both transmitter and voltage). when glutamate binds to AMPA receptor (AMPA contains sodium) the sodium goal of Nitric Oxide - goes back to presynaptic cell and further enhances glutamate release when making a memory
Two types of amnesia
1. anterograde amnesia 2. retrograde amnesia
How long term potentiation works
1. both AMPA and NMDA receptors are involved. 2. Ca2+ initiates persistent enhancement of synaptic transmission by activating Ca2+ second messenger systems.
Milner's conclusions based on Patient H.M.
1. hippocampus not location of long-term memories or short-term (immediate) memories - cannot convert new information into long term storage 2. hippocampus is necessary for consolidation, converting STM to LTM. Specifically, Milner believed that the deficit produced by hippocampal damage produced an impairment of verbal memory. mirror drawing task
OB Mice
1. ob mice: mice that have two copies of ob gene regulate their body at a higher weight. These mice have larger and more numerous fat cells a. Leptin- a protein manufactured and secreted by fat cells; regulated by the ob gene ; communicates to the brain how much fat is stored. Fat cells produce leptin and secrete it into the bloodstream. Mice with two copies of the obese gene (ob/ob), which have defective leptin genes, become obese. Defects in leptin production or sensitivity give a false reporting of body fat, causing animals to overeat. b. leptin activates nuclei in the hypothalamus (LH, arcuate, paraventricular, supraoptic) c. injecting obese rats with leptin causes them to lose weight. d. in humans, no real evidence for a defect in leptin-- obese people do produce it, in fact, they have more that thin people. It is possible they are less sensitive and not devoid of leptin. e. leptin signals suppresses the production and release of brain peptides, most notably neuropeptide Y. In the absence of leptin, NPY stimulates eating fat -> leptin -> hypothalamus (causes decrease in neuropeptide Y) -> stimulates eating (normal eating) fat--> (no leptin) --> hypothalamus --> increases NPY --> overeats
Positive and negative symptoms of schizophrenia
1. positive symptoms reflect the presence of distinctive behaviors that have been gained: delusions hallucinations (no physical stimulus - false sensations) excited motor behavior 2. negative symptoms reflect the absence of normal social and interpersonal function. disordered thoughts social isolation poverty of speech poor attention span flat of blunted affect lack of motivation
Anatomy of Anterograde Amnesia
1.) Perirhinal Cortex - region of limbic cortex adjacent to the hippocampal formation that relays information between entorhinal cortex and other regions of the brain. 2.) Parahippocampal cortex - region of the limbic cortex adjacent to the hippocampal formation that shares the same general role as the perirhinal cortex. Remember H.M.'s damage: -anterior 2/3 hippocampus -parahippocampal gyrus -amygdala But, what about the hippocampus specifically, is hippocampal damage by itself sufficient? positive correlation between the amount of damage to the hippocampus and memory performance - more damage = the greater the memory impairment
what does it mean to activate a second messenger system
1st messenger: ligand/neurotransmitter 2nd messenger: when activated, it signals cell nucleus to begin to make changes in proteins, permanent changes in the brain (cell plasticity)
Neural Control of Satiety (satisfaction) and Hunger
A dual-center hypothesis proposed two appetite centers in the hypothalamus. 1. Ventromedial hypothalamus (VMH) - SATIETY 2. Lateral hypothalamus (LH) - HUNGER KNOW THESE FOR TEST
hypotonic
A hypotonic solution is any solution that has a lower osmotic pressure than another solution. A single animal cell ( like a red blood cell) placed in a hypotonic solution will fill up with water and then burst.
Define long-term potentiation Indicate what it is, the neurotransmitter and receptors involved, where it occurs in the brain and how it relates to Hebb's rule
A memory mechanism: how memories can be formed in the brain, a type of neuronal plasticity-- biochemical and structural changes in neurons, provided evidence for Hebb's rule Hebb's rule: when axon of cell A excites cell B and repeatedly or persistently takes part in firing B, some growth process or metabolic change takes place in one or both cells so that A's efficiency in firing B is increased (how we produce long term memory) 1. both AMPA and NMDA receptors are involved. 2. Ca2+ initiates persistent enhancement of synaptic transmission by activating Ca2+ second messenger systems. Transmitter and receptors Transmitter= glutamate (excitatory) Receptors = NMDA receptors (n-methyl-D-aspartate) AMPA receptors found on post synaptic membrane in the hippocampus 2. Three important properties of the NMDA receptors: i. Abundant in the hippocampus ii. Ionotropic: high conductance permeable to cations: Ca2+, Na+, K+; (Ca2+ is most important) iii. Doubly gated (gated by both transmitter and voltage).
Negative feedback systems
A system designed to send signals to a "sensor" to "turn off" the signal when set point is reached. Temperature, hunger and thirst all us a negative feedback system. B. Set zone or set point: The desired value or zone of the internal system that is being regulated. Most systems have more tolerance than a simple set point; generally, there is a set zone which refers to the range of tolerance in a system. Fluid Regulation: Most organisms have evolved homeostatic mechanisms that maintain body fluid with a striking resemblance to seawater. We are constantly using and replenishing water and salts so we are at equilibrium. Salt doesn't pass the membrane.
Schizophrenia symptoms
A. Characteristic Symptoms: Two (or more) of the following, each present for a significant portion of time during a 1-month period (or less if successfully treated): 1. delusions 2. hallucinations 3. disorganized speech (e.g., frequent derailment or incoherence) 4. grossly disorganized or catatonic behavior 5. negative symptoms, i,e., affective flattening, alogia (poverty of speech), or avolition (inability to initiate and persist in goal-directed activities) Note: Only one Criterion A symptom is required if delusions are bizarre or hallucinations consist of a voice keeping up a running commentary on the person's behavior or thoughts, or two or more voices conversing with each other,
Making Sense of the Taxonomy of Memory
A. Temporal lobe cortex and diencephalon: Components of the same neural circuit. Activated in both encoding and retrieval of information; i.e., information processing; Not involved in storage B. Storage of information appears to take place in the neocortex: Evidence indicates that LTM are stored in the cortical circuits that mediate their original experience-- that is, secondary sensory cortex and association cortex. So if an auditory memory, stored in the superior temporal gyrus; spatial memory in the parietal lobe C. Hemispheric encoding retrieval asymmetry: a variety of evidence indicates that there is greater activation in the left hemisphere during encoding of information and greater activation in the right hemisphere during retrieval D. Patient K.C. Provides support for semantic and episodic distinction. Damage: left frontal-parietal and right parietal-occipital. KC can no longer retrieve personal information from his past, but general knowledge remains good E. Skill learning: any type of sensory-motor skill learning appears to be mediated by the basal ganglia and cerebellum
comparative studies suggest that the inability to retrieve memories of events, as experienced by patient K.C. is probably due to damage to the
cortex
The neurotrophic factor _____ has been implicated in bipolar disorder
BDNF
Efficient versus inefficient and dieting - Brownell "yo yo effect"
Brownell et. al., 1986 experiment: "yo-yo effect" Phase 1: Fed rats a high caloric diet and made them obese, then restricted their food intake, bringing them back to normal weight. It took 46 days for the rats to become "fat", and 21 days for the rats to lose the weight. Phase 2: Did it again, this time it took the rats 14 days to become fat, and required 46 days to lose the weight Conclusion: fasting decreases metabolism--that is, makes your metabolism become more efficient, so you will increase weight Benefits of caloric restriction: a reduction in metabolism seems to promote longevity. Restricted food intake promotes longevity, perhaps due to trophic factors that promote cell growth.
Chlorpromazine (Thorazine)
Chlorpromazine is used to treat psychotic disorders such as schizophrenia or manic-depression Chlorpromazine is also used to treat nausea and vomiting, anxiety before surgery replaced lobotomies as treatment for schizo, originally develop as an anesthetic reduce positive symptoms revolutionized psychiatry blocks postsynaptic dopamine D2 receptors
Genes that have been identified that appear to be abnormal in patients with schizophrenia
DISC 1, synaptic plasicity paternal age and methylation (expression of genes) play a role too
Declarative memory
Declarative memory (explicit) - things you know that you can tell others 1. Semantic memory- your memories for fact, knowing the capital of France, knowing meaning of the word without knowing where or when you learned it 2. Episodic memory- events in your life or things that occurred to you long term memory this is where people with damage to the hippocampus have problems recollection of the item in the context it was presented and the sense of familiarity with the features of the recalled item impaired in Patient HM wordlists or stories
Distinct Memory Systems
Declarative memory and Procedural Memory
Memory
Defined as a set of skills that involve the mental capacity to store and later retrieve previously experienced events. Or, the ability to encode, store and retrieve previously experienced events. biochemical and structural changes in the brain
Walter Freeman
Doctor who streamlined lobotomies, made them extremely common. He shocked patients into unconsciousness instead of anesthesia, and used an ice pick through the eye to get to the brain. read work by Moniz and saw this a surgery that could be performed and changed name to lobotomy (kansas housewife received first one), invented ice pick technique of lobotomy Moniz - "leucotomy"
Homeostasis
Homeostasis is the active process of maintaining a relatively stable, enhance internal environment; The tendency for the internal environment to remain constant. Regulation of our internal resources is complicated by the fact that staying alive requires obligatory losses of some resources, which in turn necessitates us to gain and conserve them.
Hypovolemic thirst
Hypovolemic thirst: low extracellular volume of water a. Hypovolemic thirst is triggered by a loss of water volume—the concentration is not changed; blood loss (hemorrhage) is an example. Baroreceptors (detect BP) in major blood vessels and the heart detect the initial drop; the heart decreases secretion of atrial natriuretic peptide (ANP) which causes a compensatory increase in blood pressure. In the absence of ANP, blood pressure increases, and water excretion decreases (increases in BP = vasoconstriction) b. The renin-angiotensin system-- the kidneys also detect decreased blood flow, causing them to release renin i. renin is released into circulation, causing the angiotensin cascade c. Circumventricular (around the ventricles) organs: Angiotensin II also affects behavior—it acts in the brain to trigger drinking. Circulating angiotensin II acts on the circumventricular organs, which signal other brain sites. The subfornical organ is particularly sensitive to angiotensin II, and its stimulation strongly elicits drinking behavior.
Diffusion
In diffusion, molecules of a substance, like salt (a solute), dissolved in a quantity of another substance, such as a glass of water (a solvent), will passively spread through the water.
confabulation is a symptom of
Korsakoff's disease
LSD-induced psychosis differs from schizophrenia in that
LSD-induced psychotic states produce visual hallucinations
What is learning?
Learning is the process of acquiring knowledge about the world-- a relatively permanent change in behavior as a result of experiences.
Physiological evidence for synaptic modification
Long-term potentiation-- A memory mechanism: how memories can be formed in the brain, a type of neuronal plasticity-- biochemical and structural changes in neurons, provided evidence for Hebb's rule Hebb's rule: when axon of cell A excites cell B and repeatedly or persistently takes part in firing B, some growth process or metabolic change takes place in one or both cells so that A's efficiency in firing B is increased (how we produce long term memory)
write a paragraph including: osmotic thirst, hypovolemic thirst; baroreceptors; osmoreceptors; hormones
Osmotic thirst (independent of extracellular volume) is triggered by a loss of water in extracellular fluid that produces a change in the solute concentration (urination, perspiration) Hypovolemic thirst is triggered by a loss of water volume—the concentration is not changed; blood loss (hemorrhage) is an example. Baroreceptors (detect BP) in major blood vessels and the heart detect the initial drop; hormones such as ANP and vasopressin are affected by this drop -- decreasing the secretion of ANP and increasing the release of vasopressin
Obesity: Genes, Surgery and Nervous Disorders
Our multiple, redundant systems for appetite and energy management work all too well in fighting against weight loss. Evidence is accumulating that parental obesity may program metabolic disadvantages in offspring via epigenetic transmission, a process affecting the expression of a particular gene or genes, without affecting the sequence of nucleotides making up the gene itself.
Patient K.C.
Provides support for semantic and episodic distinction. Damage: left frontal-parietal and right parietal-occipital. KC can no longer retrieve personal information from his past, but general knowledge remains good
comparing the basal metabolic rates of two animals, each with a body weight of 100 grams you discover that species A has a higher metabolic rate than species B. Which animal is most likely a mammal
Species A
Environmental risk factors for developing schizophrenia
Stress—puberty or going off to college •City life •Prenatal exposure to influenza (the seasonality effect) •Low weight or lack of oxygen at birth
Dopamine Theory of Schizophrenia
The DA dysregulation model 1. Hypofrontality and glutamate Under active frontal lobes Glutamate is found in frontal lobe, project to/activate nucleus accumbens Independent causes of positive and negative symptoms: In normal individuals: glutamate projects to VTA and causes excitation In hypofrontal patients: less excitation, circuit will not be complete, don't experience reward, results in up regulation of receptors due to a lack of glutamate input in VTA
Neurochemical Theories of Schizophrenia
The Dopamine Hypothesis: 1. Data consistent with the DA theory a. first generation antipsychotics cause extrapyramidal symptoms (Parkinson's like side effects) by blocking dopamine receptors b. L-dopa worsens psychosis when given for EPS c. reserpine (depletes catecholamines) and AMPT (blocks tyrosine hydroxylase - helps in creation of dopamine) reduce symptoms by decreasing dopamine levels d. antipsychotic efficacy is correlated with affinity for D-2 receptor antagonism e. high doses of amphetamine cause psychotic symptoms to treat give a dopamine antagonist
write a paragraph including: thirst; renin; angiotensin II; circumventricular organs; behavior
The renin-angiotensin system-- the kidneys also detect decreased blood flow, causing them to release renin. Renin is released into circulation, causing the angiotensin cascade. Angiotensin II (produced by this cascade) also affects behavior—it acts in the brain to trigger drinking behavior. Circulating angiotensin II acts on the circumventricular organs, which signal other brain sites.
Episodic memory concerns
autobiographical information (Autobiographical memory is a memory system consisting of episodes recollected from an individual's life, based on a combination of episodic and semantic memory. It is thus a type of explicit memory.)
describe the role of the ventromedial hypothalamus and lateral hypothalamus as they relate to food and energy regulation mention "hunger center" and "satiety center" and explain why these terms are misnomers with respect to the role of these structures in eating behavior
Ventromedial hypothalamus - responsible for appetite suppression - destruction of this no longer satiated, so animal continues to eat-- caused researchers to call this area the satiety center (a misnomer because they actually aren't satiated) LH promotes feeding behavior - bilateral lesion of the LH produces aphagia-- animals stop eating. Thus, LH was called the hunger center. (not actually hungry)
long term potentiation
a stable increase, lasting hours or days, in the magnitude of the EPSP as a result of repetitive neuronal stimulation
hebbian synapse
a synapse that is strengthened when it successfully drives the postsynaptic cell
working memory
a type of short term memory that holds information available for ready access during performance of a task
Anorexia nervosa and bulimia
a. Anorexia-- suppress the urge to eat, sometimes regurgitating food. Teeth rot, menstrous stops, osteoporosis, widening of sulci and ventricles b. Altered body self-image. Often respond to food more than normals, so they are depriving themselves of food. Hot cinnamon rolls: blood samples indicate that anorexic blood insulin levels higher in anorexic c. Seem to be preoccupied with food: will cook for others, collect recipes. d. Often exercise, increased activity is thought to reduce feelings of hunger e. Anorexia nervosa is notoriously difficult to treat because it appears to involve an unfortunate combination of genetic, endocrine, personality, cognitive, and environmental variables. e. Bulimia- characterized by a loss of control of food intake. Gorge themselves and then purge themselves
Three mechanisms of insulin release
a. Cephalic phase: sight, smell of taste of food; body is conditioned to release insulin (classical conditioning) b. Digestive phase: food in the stomach and intestines causes the release of gut hormones, some of which stimulate the pancreas to release insulin c. Absorptive phase: glucose in the blood stimulates glucodetectors in the liver, signaling the pancreas to secrete insulin, most of storage will take place here
Diabetes mellitus (Ln; sweetened with honey)
a. Type I (juvenile onset)-- the pancreas stops producing insulin. Brain can still use glucose from diet, but the rest of the body cannot, so start breaking down fatty acids. Because the body is breaking down fatty acids, can result in extra ketone bodies (i.e., acidic products) causing acidosis (ketoacidosis). Acidosis is a major cause of coma and death in diabetics via brain dysfunction excedes reabsorption capacity of kidney and it goes to the urine, pull LOTS of water out to reduce the solvents too much sodium creates hypertension, too little creates hypotension - leads to coma/death Chronic malnourishment b. Type II diabetes (insulin resistant) older/overweight individuals: hyporesponsiveness to insulin, target cells do not respond normally to insulin; perhaps a down-regulation of insulin receptors. Someone who always overeats secretes, on average, more insulin, body down-regulates to compensate dietary manipulation - stop eating as many carbs
Surgical Removal of Fat
a. body weight and body fat is carefully regulated b. ground squirrels fatten up in the spring, regardless of the food supply. Only way to change this is force-feeding of food restriction c. when fat is surgically removed, the squirrels regain, exactly the amount of fat before the surgery
Satiety signals
a. insulin: low or high amount of circulating insulin triggers eating. b. Gut peptide hormones: PYY3-36 is secreted by cells in the intestines. Its levels are low before eating but rise rapidly after a meal. It also acts in opposition to ghrelin, acting as an appetite suppressor. c. Ghrelin is released into the blood by endocrine cells in the stomach. Besides stimulating growth hormone release, ghrelin is an appetite stimulant. Levels of ghrelin rise during fasting and fall after a meal, except in obese subjects where ghrelin levels remain high.
Lesions in the lateral hypothalamus produce what effect?
abolished behavioral regulation of temperature but did not affect the physiological responses
besides increasing blood pressure and causing drinking, angiotensin II stimulates the release of ______ which is crucial to Na+ conservation
aldosterone
Phencyclidine (PCP)
an anesthetic agent that is also a psychedelic drug makes many people feel dissociated from themselves and their environment, resembles schizo acts as NMDA receptor antagonist, blocking calcium channel and glutamate cannot produce its normal effects
anterograde amnesia
an inability to form new memories the inability to transfer new information from the short-term store into the long-term store
retrograde amnesia
an inability to retrieve information from one's past
endophenotype
behavioral or physical characteristics accompanying susceptibility to a particular disorder, which may be used to identify those at risk trouble with smooth eye pursuit
Lateral hypothalamus (LH)
bilateral lesion of the LH produces aphagia-- animals stop eating. Thus, LH was called the hunger center. Again, this is oversimplified for two reasons: a. animals also show adipsia (no drink) b. if the rat was somehow kept alive, the eventually will spontaneously eat. moves the set body weight to a lower level It appears that once recovered, LH lesioned rats do regulate their body weight: the larger the LH damage, the lower the level of target body weight. That is why they do not eat.
effects of angiotensin cascade
blood vessels constrict, increase in blood pressure vasopressin is released aldosterone is released circumventricular organs trigger drinking
describe the relationship between the brain and glucose
brain can only use glucose; brain therefore requires a constant supply of glucose which it can use without insulin
The increase of cortical thickness with enriched experience is probably mainly due to the increased
branching of dendrites
Glycogenolysis
breakdown of glycogen into glucose triggered when blood concentrations of glucose drop too low
suddenly losing fluids from blood loss does not
change the concentration of of the extracellular fluid because salts and other solutes are lost along with water only volume of ECF is effected example of redundancy in system because changes in volume alone are sufficient enough to induce drinking
which neurosurgical operation leads to a marked reduction in the intensity of OCD symptoms?
cingulotomy
Which statement regarding therapy for depression is true?
cognitive behavioral therapy and SSRI treatment together are more effective than either one alone
Edward Tolman is associated with the concept of
cognitive maps - mental representation of a spatial relationship
Compared to animals placed in impoverished conditions, animals kept in enriched conditions had been found to have heavier brains, due primarily to increases in the
cortex
which brain damage would not be associated with an inability to forms declarative memories
damage to the anterior cerebral cortex
liposuction would not be expected to reduce hunger because of the subsequent
decrease in leptin production
Ventricular enlargement of the brains of some patients with schizophrenia appears to be related to
decreases in the volume of adjacent neural tissue
Ventromedial hypothalamus (VMH)
destruction of this no longer satiated, so animal continues to eat-- caused researchers to call this area the satiety center (a misnomer) This is called VMH syndrome and is more complicated than just over-eating: (hyperphagia) -animals are finicky (quinine added, will not eat) -chose carbohydrates -stimulates insulin and decreases glucagon: so cannot release stored energy, so has to keep eating: essentially the body is starving to death -bilaterally destroying reestablished body weight set point to a higher weight
compare and contrast diabetes insides and diabetes mellitus
diabetes insipidus-- body does not produce vasopressin, so the kidneys retain less water, producing copious amounts of diluted urine Mellitus: a. Type I (juvenile onset)-- the pancreas stops producing insulin. Brain can still use glucose from diet, but the rest of the body cannot, so start breaking down fatty acids. Because the body is breaking down fatty acids, can result in extra ketone bodies (i.e., acidic products) causing acidosis (ketoacidosis). Acidosis is a major cause of coma and death in diabetics via brain dysfunction excedes reabsorption capacity of kidney and it goes to the urine, pull LOTS of water out to reduce the solvents too much sodium creates hypertension, too little creates hypotension - leads to coma/death Chronic malnourishment b. Type II diabetes (insulin resistant) older/overweight individuals: hyporesponsiveness to insulin, target cells do not respond normally to insulin; perhaps a down-regulation of insulin receptors. Someone who always overeats secretes, on average, more insulin, body down-regulates to compensate
Adipose tissue
fat cells represent our long-term store Gluconeogenesis is the process of converting fat and proteins to glucose and ketones, a form of fuel. byproduct of what happens when the body breaks down fat
the amygdala is directly involved in
fear conditioning
kidneys job
filter blood
Gluconeogenesis
formation of glucose from fats and proteins
glucogenesis
forming or producing glucose
Functional imaging studies indicate that drugs that alleviate symptoms of schizophrenia tend to increase activation of the
frontal cortex
Nucleus of the solitary tract (NST)
in the medulla (when glucose levels are low you activate this structure) Information from the liver (e.g., glucodetectors) travels via the vagus nerve (stimulates internal organs) to the NST----which stimulates the hunger center in the hypothalamus
during the absorptive phases special cells in the liver, called glucodetectors, detect circulating glucose and trigger the release of
insulin
H.M.'s performance on the mirror tracing task showed that he could acquire a kind of _______ memory.
long term
CREB appears to be essential for the formation of _______ memories.
long term transcription factor activated by protein kinases
What does the body do when it's starving with respect to homeostasis?
lowers temperature, burns fat, changes metabolism
Behavioral homeostasis
maintenance of appropriate living conditions by using behavior to achieve those conditions by minimizing their fluctuations change exposure of the body surface (huddling) change internal insulation change surroundings (move into the sun) especially important for ectotherms
what is the major neurotransmitter theory concerning the causes of MDD? Also list three classes of antidepressant drugs used in treatment and the mechanism of action of each class
monoamine theory of depression -depression is the result of under activity of NE/5-HT (serotonin) agonistic drug classes: MAOI's - inhibit the break down of monoamines in the presynaptic terminal Tricyclic AD's - block the re uptake of serotonin/NE SSRI's - selective serotonin re uptake inhibitor, keep serotonin in the synapse longer so it has a better chance of connecting with the receptors all enhance BDNF (enhance cell survival)
What can H.M. learn?
motor learning - mirror drawing task, don't remember doing it on day 2 but their performance is consistent perceptual learning
Available energy from ingested food is used in three activities:
note only 75% is available for use 1. Processing newly ingested food: 8%-- both metabolic rate and heat production rise after eating. 2. Basal metabolism: 55% is used for maintaining body heat and other resting functions. Basal metabolism is energy used for heat production, maintenance of membrane potentials, and life-sustaining processes. 3. Active behavioral processes: 12-13% of energy, larger if more active environment (physical activity)
the cortex is essential for long term storage of memories
patient KC - unable to retrieve memory of his past (episodic memory) although general knowledge remained
lesions in the preoptic area impaired
physiological responses to cold (shivering and constriction) but did not interfere with behaviors such as pressing levers to control heating lamps or cooling fans
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 reverberating circuit - how we maintain things in short term memory Hebb's rule: when axon of cell A excites cell B and repeatedly or persistently takes part in firing B, some growth process or metabolic change takes place in one or both cells so that A's efficiency in firing B is increased (how we develop long term memories)
Endothermic advantages
range more widely evolved a greater capacity for oxygen utilization can sustain high levels of muscular activity for longer periods of time
Hypovolemia causes
release of vasopressin, or antidiuretic hormone (ADH), from the posterior pituitary gland which further induces blood vessel constriction and reduces water flow to the bladder. diabetes insipidus-- body does not produce vasopressin, so the kidneys retain less water, producing copious amounts of diluted urine
Homeostatic regulation of salt
salt is crucial for fluid balance if extracellular compartment contained pure water, osmotic pressure would drive it into the cells, causing them to rupture if extracellular fluid lacks salt, we shed water through urination until it returns to isotonic the amount of water we can retain is determined primarily by the amount of salt contained in extracellular fluid
family studies of schizophrenia reveal that
schizophrenia is more evident among first degree relatives of patients than it is among more distant relatives
CCK (cholecystokinin)
secreted by cells of duodenum (small intestine) suppresses appetite via direct action on the vagus nerve
PYY3-36
secreted by cells of the ileum (small intestine) and colon provides rapid signal that food has been consumed, prompting the arcuate system (arcuate nucleus of hypothalamus) to suppress appetite suppresses eating behavior
perirhinal cortex
sense of familiarity in memory whereas recollection of the item is the function of hippocampus
antidepressant medications are more effective than placebo in subjects who are
severely depressedantag
Leptin
suppresses appetite (eating behavior) and increases energy expenditure secreted by fat cells signals current long term energy stores
Producing long-term potentiation in the laboratory
take a slice of hippocampal tissue, take a baseline measurement by providing a single pulse of electricity, measure output (small depolarization), provide a burst of input into that cell, wait and then apply one more pulse and the output goes from the baseline and skyrockets
a common movement disorder produced by anti schizophrenia drugs, called ____, may affect as many as 1/3 of patients taking those drugs
tardive dyskinesia
Patient HM showed
that STM differs from LTM caused by loss of medial temporal lobe, including hippocampus
role of insulin in energy utilization
the body can make use of fatty acids or glucose for energy, body needs insulin to use glucose so if it absent the body must use fatty acids brain can only use glucose; brain therefore requires a constant supply of glucose which it can use without insulin
osmolality
the concentration of solutes in body fluids NaCl in the extracellular fluid of mammals
allostatic load (allostasis)
the cumulative long-term effects of the body's physiological response to stress
osmosis
the passive movement of water molecules, through a semipermeable membrane, from one place to another (salt doesn't pass)
glutamate hypothesis of schizophrenia
the problem relates in part to deficient activity at glutamate synapses in the prefrontal cortex understimulation of glutamate receptors
Tricyclic antidepressants inhibit
the reuptake of norepinephrine, serotonin, and/or dopamine.
Pancreatic hormones control
the storage or release of glucose a. glucagon: breaks down glycogen into glucose: Glucagon, another pancreatic hormone released by alpha cells in the islets of Langerhans, mediates glycogenolysis—conversion of glycogen back into glucose when blood glucose levels drop. beta cells in the pancreas create insulin b. insulin: converts glucose into glycogen for storage
lobotomy
the surgical detachment of a portion of the frontal lobe, used as a treament for schizo
osmotic pressure
the tendency of a solvent to move through a membrane in order to equalize the concentration of solute; the force that pushes or pulls water across the membrane
homeostatic redundancy
two different systems for regulating the same variable
obligatory losses
unavoidable loss of a regulated variable, such as energy, water, or temperature, as a consequence of life processes
Newly released insulin allows the body to
use some of the glucose immediately and also begins storing the glucose
the receptors that detect hypovolemia are located in the
vascular system
circumventricular organs
weak areas of BBB so brain can monitor blood quality, capillary structure is weaker subfornical organ, organum vasculosum of the lamina terminals (OVLT), area postrema
write a paragraph incorporating: primacy effect; recency effect; anterograde amnesia; LTM; STM
when studying a list of words, you may remember the first few words really well which is known as the primacy effect and/or the last few words which is known as the recency effect. air the delay prior to recall is a few minutes, there is no recency effect and is thus attributed to working memory (STM). The primacy effect, however, lasts longer and is attributed to LTM
isotonic
when the concentration of two solutions is the same
