PSYC 220 Exam 3/Final
once LTP has been established
NMDA synapses are no longer needed, once LTP has been established - NMDA antagonists = prevent establishment of LTP • but remember that the changes may take a few hours to a few days • they do not interfere with maintenance of LTP
oxytocin
a pituitary hormone also important for reproductive behavior • stimulates contractions of the uterus during delivery • stimulates the mammary gland to release milk • sexual pleasure releases oxytocin, esp. at orgasm
Morning vs. Evening person depends on
age but also genetics and other factors • living in a city with bright lights makes you more likely to stay up late than a person from a rural area
Explicit memory
aka declarative memory; about things you remember that you can say • Semantic memory • Episodic memory
beta waves
alert wakefulness
biological predisposition to homosexuality may be stronger
among men
Sodium specific hunger
an immediate strong preference for salty tastes when sodium deficiency occurs - Specific hungers for other vitamins and minerals have to be learned by trial and error - Depends partly on hormones • Aldosterone
sleep paralysis
an inability to move (cataplexy) while falling asleep or waking up
Sensitization
an increase in response to mild stimuli as a result of exposure to more intense stimuli
Fever
an increased set point for body temperature caused by an infection - when you have a fever (Ex. 102 F) you shiver or sweat whenever your temperature deviates from that level - not caused by an infection, but by the hypothalamus to fight the infection • certain types of bacteria grow less vigorously at high temperatures • immune system works more vigorously at high temperatures
Implicit Memory
an influence of experience on behavior even if you do not recognize that influence - e.g. mirror drawing task → draw image from a mirror image • HM would think he'd never done a task and be really good at it (because he'd actually done it before but just didn't remember episodically) - (others with amnesia): saw falling blocks (Tetris) when sleeping but didn't know why do to poor episodic memory - 3 nurse experiment
Output from the ventromedial hypothalamus (VMH)
inhibits feeding
Serotonin
inhibits sexual activity by blocking dopamine release • Why SSRIs decrease sex drive
problem in Testicular Feminization/Androgen Insensitivity
insensitivity to testosterone
mother's immune system may exert prenatal effects
probability of a homosexual orientation is higher among men with more biological older brothers • mother's immune system sometimes reacts against a protein in a son and then attacks subsequent sons enough to alter their development
Central Nervous System Sleep Apnea
problem with medulla
Negative feedback
processes that reduce discrepancies from the set point
Organizing effects
produce long-lasting structural effects • sensitive period
most overweight people, however
produce plenty of leptin they're just insensitive to it
L-acetylcarnitine
produces epigenetic changes on glutamate receptors with rapid antidepressant effects and few side effects
thiamine is needed for
proper metabolism of glucose - sometimes malnourished people experience brain damage when given food because of this • to prevent, must be given thiamine before fed
hormone changes during pregnancy prepare a female to
provide milk and to prepare care for the young
in adolescence a certain level of leptin triggers
puberty
evidence for safety from predators
rabbits are most active during the night
Radial maze
rats with hippocampal damage learn to never enter arms that never have food but even after much training they often enter a correct arm twice, forgetting which ones they've already tried
NMDA receptor
receptor excited only by glutamate, but can respond to NMDA - Different ionotropic receptor --> its response to the transmitter glutamate depends on the degree of polarization across the membrane
nicotine
stimulates the satiety neurons in the arcuate nucleus - cigarette smoking decreases appetite; quitting increases
single gene mutations account for only
~5% of severe obesity
4 main symptoms of narcolepsy
• gradual or sudden attacks of sleepiness during the day • cataplexy • sleep paralysis • hypnagogic & hypnopompic hallucinations
Stages of sleep
- beta waves - alpha waves - stage 1 sleep/theta waves - stage 2 sleep/theta waves with sleep spindles and K-complexes - stage 3 (delta waves <50%) - stage 4 (delta waves >50%) - REM sleep
How do steroids make an effect?
- bind to membrane receptor - bind to cytoplasm proteins - bind to chromosomes • e.g., sex-limited genes
steroids exert effects in 3 ways
- bind to membrane receptors like neurotransmitters exerting rapid effects - enter cells and activate certain kinds of proteins into the cytoplasm - bind to receptors that bind to chromosomes where they activate or inactivate certain genes
Osmotic thirst stimulus
High solute concentration outside cells causes loss of water from cells
equipotentiality
all parts of the cortex contribute equally to complex behaviors such as learning, and any part of the cortex can substitute for any other - although many brain areas contribute to learning, they are not necessarily doing the same thing
Delayed response task
as task in which you respond to something that you saw or heard a short while ago - during the delay • learner has to store a representation of the stimulus • certain cells in the prefrontal and parietal cortexes increased their activity
parietal lobe
associates one piece of information with another - spontaneous association between memories • those with damage do not elaborate on memories spontaneously
cataplexy
attacks of muscle weakness while a person remains awake - often triggered by strong emotions, such as anger or great excitement
one theory is that addictive behaviors are
attempts to avoid withdrawal • BUT cocaine addicts use even though withdrawal is mild
most daily energy (daily avg. for young adult = 2600 kcal) goes to
basal metabolism
women often seek other characteristics like
be a good provider • as such, women tend to be cautious during courtship to prevent a man acting interested then leaving when she needs him
untreated diabetes weight loss
because body cannot use fuel
acetylcholine agonists
because of the destruction of the basal forebrain - increase acetylcholine, increases memory function for a while - most common treatment is to stimulate or prolong acetylcholine release thereby increasing arousal
we normally end a meal
before the food reaches the blood, muscles, brain, or organs because our stomachs become distended • stomach distension is sufficient to produce satiety
negative symptoms of schizophrenia
behaviors that are absent that should be present • stable over time and difficult to treat
positive symptoms of schizophrenia
behaviors that are present that should be absent • delusions, hallucinations, disorganized speech
↑ leptin =
better mood
naloxone and naltrexone
block opiate receptors and thereby decrease the pleasure from alcohol • only moderately helpful • vary in part with people's motivation to quit
stimulant drugs work to
block reuptake of released dopamine or reverse the dopamine transporter so that it release dopamine instead of producing reuptake
nefazodone
blocks 5-HT-type 2 A receptors, blocks some reuptake of 5-HT, NE
venlaxafine
blocks reuptake of 5-HT, some NE, DA
If insulin levels stay low (type 1 diabetes)
blood glucose levels may be three or more times more the normal level, but little of it enters the cells • these people and animals eat more food than normal because their cells are starving but they excrete most of their glucose and they lose weight
diabetes I
body does not produce enough insulin
Poikilothermic
body temperature matches the temperature of the environment (aka ectothermic) - amphibians, reptiles, most fish - lack physiological mechanisms of temperature regulation such as shivering and sweating and instead regulate body temp behaviorally • less constancy with behavioral methods
high blood sugar
body wants to flush it out by peeing a lot
Sleep-talking
both NREM and REM
migraines in blind people
bright light aggravates migraines in blind people because these cells send input to the posterior thalamus which is part of the pain pathway for migraines
ketosis
build up of ketones (byproduct of fact breakdown in blood) • not bad
(rats) hippocampal damage
can learn a new task but forget quickly
animal with osmotic thirst needs water, but one with hypovolemic thirst...
cannot drink much pure water because pure water would dilute its body fluids and lower the solute concentration in the blood so the animal needs salty water • Sodium specific hunger
more men than women seek opportunities for
casual sexual relationships with many partners - no genes controlling this
Androgens and Estrogens
categories of chemicals
high estradiol and progesterone
cause fluctuating activity at the 5HT3 receptor which causes nausea • may be evolved to decrease risk of eating something harmful
most neurologists assume learning depends on
changes at synapses
working memory
characterization of STM as a modular system for temporary storage and manipulation of information - consists of 4 components -- phonological loop -- visuospatial sketchpad -- central executive -- episodic buffer
Polysomnograph
combination of the following graphs - electroencephalogram (EEG) - electrooculogram (EOG) - electromyogram (EMG)
most cases of obesity relate to
combined influences of genes and environment
several other chemicals contribute to the control of appetite
consequently, the control of feeding can go wrong in many ways but the brain has many ways to compensate
Central Executive System
controls the deployment of attention, switching the focus of attention and dividing attention as needed - have control over what you think about
Splanchnic nerves
convey information about the nutrient contents of the stomach
reproductive cells require
cooler environment than the rest of the body - birds insulate eggs outside of body to keep them cooler - the scrotum hangs outside the male body to keep sperm cooler • men who wear too tight of underwear have a lower sperm count because their scrotum is too warm - pregnant woman are advised to avoid hot baths/anything that could overheat the fetus
REM and corneas
corneas get oxygen by moving - some say REM sleep may be adaptive to prevent corneal damage - BUT SSRI users who have decreased REM do not have cornea damage
daily changes in sex drive in women, however,
correlate with levels of estradiol not testosterone
safety from predators
creatures stow themselves away while sleeping • BUT lions sleep a tremendous amount → not worried about predators
Cerebellum
critical for many other instances of classical conditioning, but only if the delay between the onset of the CS and the onset of the UCS is short
primary sexual characteristics
critical, basic, primary for sexual reproduction but does NOT occur first - female → maturation of eggs, ovulation, menstrual cycle - example: hypothalamus (gonadotropic-releasing hormone) → anterior pituitary (FSH, LH) → - male → production of sperm, increased testosterone secretion
folic acid (vitamin b9)
cuts risk of autism in half when mothers take it
gender differences in release of hormones in hypothalamus
cyclical (females) vs. steady (males) release of hormones • females → menstrual cycle
ventromedial hypothalamic syndrome
damage to VMH that causes rapid weight gain due to eating normal-sized meals very frequently that finally levels off at a stable but high set point and total food intake declines to nearly normal levels • must also be accompanied by damage outside the VMH
medical resident students
- 95-136 hours/week - 84% scored at a level consistent with clinical sleep disorders on the - 41% cited fatigue as factor in greatest error - in 1/3 of cases, the patient died - June-July new medical residents- super tired and not used to schedule
Anorexia Nervosa (DSM-IV-TR)
- < 85% of normal weight - intense fear of getting fat - body image distortion - amenorrhea → NOT in DSM V; occurs but is not a defining criteria - restricting vs. binge/purge subtype
Hormones that increase sleepiness
- Adenosine - Prostaglandins - GABA
- Better Implicit than Explicit Memories
- Explicit memory: - Implicit memory: • (others with amnesia): saw falling blocks (Tetris) when sleeping but didn't know why do to poor episodic memory
Characteristics of Stages 3 & 4 (aka SWS)
- Eyes → roll up & down - metabolism is lowered 20%, brain is still active but people are really hard to wake up and if they do wake up they're very groggy
many people believe that eating sugar makes children hyperactive but
studies have found no significant effects of sugar on children's activity level, play behaviors, or school performance
risk of accidents may ↑
• 3 mile island- ferry accidents • medical resident students • BAC level of near .08 = sleep deprivation for about 24 hours (vigilance task) • More than 70,000 car crashes (1,550 fatal) per year are due to sleepy drivers (2003). Shift workers also have increased rates of accidents.
Prader-Willi syndrome
• 4-5X higher level of ghrelin • not most obese
Brain areas involved in SWS - stages 3 and 4
• Basal Forebrain • Preoptic Area
The Hippocampus and Declarative Memory
• Delayed Matching-to-sample task • Delayed Nonmatching-to-sample task
Treatments to delay/manage symptoms NOT cure
• Don't know what is causing alzheimer's • acetylcholine agonists • antioxidants • immunization • THC/marijuana
OVLT also receives input from receptors in
the digestive tract, enabling it to anticipate an osmotic needs before the rest of the body experiences it
Factors which ↑ or ↓ eating
• Glucose • insulin • stomach & intestines • oral factors • leptin • gherkin • Taste input • Learning
Intact Working Memory
• HM had intact working memories although he did it strangely • Intact intelligence
obese: high or low levels of leptin?
• High levels in blood stream • Low levels in CSF
No new antidepressants in years, but some potentials
• Ketamine • L-acetylcarnitine
why as evolution not selected against homosexuality if it doesn't result in offspring?
• Maintained by kin selection → homosexual people might do a great job helping raise nieces and nephews • Genes that produce male homosexuality might produce advantageous effects in their relatives, increasing their probability of reproducing and spreading their genes • Relates to epigenetics rather than changes in DNA sequence
LTP induction - Glutamate receptors
• NMDA (*special) • AMPA • Kainate • Metabotropic receptor
What can affect protein synthesis?
zeitgebers light → SCN → ↓ Tim & Per → ↓ sleepiness - bright light during early evening leads to phase-delay of the rhythm - bright light during later part of night leads to phase-advance of the rhythm
postsynaptic structural changes
• increased BDNF • increased AMPA receptors (or moves them around) • increased # NMDA receptors • increased dendritic branching • increased responsiveness of AMPA receptors (possibly)
during REM sleep activity...
• increases in the pons and the limbic system and parts of the parietal and temporal cortex • decreases in the primary visual cortex, the motor cortex, and the dorsolateral prefrontal cortex
strong influence of genetics on vulnerability to alcoholism and other drugs, esp. cocaine
• individual genes though haven't been identified • many genes for alcoholism also code for mood, conduct, and antisocial personality disorders
amyloid-β causes
damages dendritic spines, decreases synaptic input, decreases plasticity - these damaged structures cluster into structures → plaques • plaques accumulate in → cerebral cortex, hippocampus • other areas atrophy (waste away)
those with schizophrenia have
decreased glutamate
sleep depends partly on
decreased sensory input to the cerebral cortex
THC/marijuana
decreases excitatory activity and amyloid plaques trigger too much glutamate
sleep deprivation and memory
deficits on memory tasks
Explicit Memory
deliberate recall of information that one recognizes as a memory - Aka declarative memory
addiction
dependence • paradoxical because as it progresses the pleasures become weaker while the costs and risks increase
siwfts
first flight takes two years but these birds seem to sleep for brief periods of time because their wings stop flapping for periods of time and they just cruise - could be a problem for predators getting them, for flying off course, running into something, temperature
as a result
follicle produces increased amount of estradiol which causes an increased release of FSH and LH which causes the follicle to release an ovum
have people drink alcohol then take a drug that produces nausea
forms learned aversion to the taste of alcohol
bipolar I
full-fledged manic episodes
gene that controls COMT
gene that breaks down dopamine - more active form of gene → breaks down more dopamine; tends to decrease reinforcement • these people are more impulsive
DISC1
gene that controls differentiation and migration of neurons in brain development, production of dendritic spines, and the generation of new neurons in the hippocampus • rare variants are more common in those with schizophrenia
circadian rhythm period length
generally 24 hours, but not always • we may readjust daily (i.e. weekdays vs. weekends)
parts of the female hypothalamus
generate a cyclic pattern of hormone release (menstrual cycle) • neither males nor females exposed to a lot of testosterone early on can do this
Sexual Selection
genes that make an individual more appealing to the other sex will increase the probability of reproduction and therefore the next generation will resemble those who held those genes
for years, most intersexes were raised as
girls on the assumption that surgery could make them look like normal girls and they would develop behaviors corresponding to the way they were reared
digestion converts much of a meal into
glucose, an important source of energy throughout the body and nearly the only fuel of the brain
mostly LTP depends on changes at
glutamate synapses
phase advance
go to sleep earlier to awaken earlier which most people find more difficult
type I/A alcoholism
gradual development of alcoholism, usually after age 25 • depends more on a stressful lie and less on genetics • generally less severe, responds better to treatment
morning people report being...
happier than evening people perhaps because their 9-5 schedule is more in line with their sleep schedule
Hypothalamus
has several axon pathways that influence arousal • Tuberomammillary nucleus • Lateral (& posterior) hypothalamic nuclei • other pathways in the lateral hypothalamus
Korsakoff's and alcoholism
have a lot of calories so people don't feel hungry so it's easy to become malnourished
PCP drug
inhibits the NMDA glutamate receptors • at larger doses produces both negative and positive symptoms of schizophrenia
immediately before, during, and after a meal, the pancreas increase release of
insulin - Some excess glucose enters the liver and is stored as glycogen and others enter fat cells and are stored as fat - As time passes after a meal, the blood glucose level falls, insulin levels drop, glucose enters the cells more slowly, and hunger increases which stimulates the pancreas to release more glucagon
two pancreatic hormones regulate the flow of glucose into cells
insulin and glucagon
Factors which ↑ or ↓ eating - insulin, direct effects
insulin causes body to feel full
lateral hypothalamus controls
insulin secretion, alters taste responsiveness, and facilitates feeding in other ways
Factors which ↑ or ↓ eating - insulin, indirect effects
insulin working (taking sugar out of blood) makes us feel hungry
Transcranial magnetic stimulation
intense magnetic field applied to the scalp which stimulates axons near the surface of the brain
In The Experimental Stage - propranolol
interferes with protein synthesis therefore preventing reconsolidation • when injected in cocaine users during videos of cocaine cues, weakened craving response to same videos a day/week later
birth control pills prevent pregnancy by
interfering with the usual feedback cycle between the ovaries and the pituitary
serotonin and norepinephrine
interrupt REM sleep • 5-HT & NE = ↓ or no REM
Stage 1 Sleep/theta waves
irregular, jagged low-voltage waves • brain activity is less than in relaxed wakefulness but higher than other sleep stages
alcohol withdrawal
irritability, fatigue, shaking, sweating, nausea - severe → hallucinations, convulsions, fever, cardiovascular problems
Senility
is NOT a normal part of aging
dieting alone
is not effective because people don't stick to diets so weight loss is not maintained if it occurs at all • now recommended to make subsequent small changes in diet
a drug has an affinity for a receptor if
it binds to it • affinities vary from strong to weak
When the PVN is activated
it inhibits LH activity (so it results in satiation). It can inhibit the PVN (as well as the satiety-arcuate nucleus) by secreting chemicals like NPY, AgRP, & GABA.
When angiotensin II reaches the brain
it stimulates neurons in areas adjoining the third ventricle that send axons to the hypothalamus where they release angiotensin II as their neurotransmitter • Neurons surrounding the third ventricle both respond to and release
Entry of calcium is
key to maintaining LTP because it activates CaMKII protein
semantic dementia
knew things were supposed to be used in certain times but didn't know how?; loss of semantic memory • Held a closed umbrella over his head during a storm • Ate yogurt on top of frozen raw salmon
alogia
lack of speech
output from the PVN acts on the
lateral hypothalamus
D2 receptors stimulated by high concentrations
lead to orgasm
prefrontal cortex contributes to
learned behavior and decision making - working memory - learning of reinforcements & punishments (reward system) • ventromedial → assesses reward to be expected, based on past • orbitofrontal → assess reward based on comparison with other choices
leptin sensitivity in pregnancy and hibernation
leptin sensitivity declines during pregnancy and in animals preparing for hibernation and as a result of obesity • as obesity develops, the effect of leptin reverses so that it increases eating • only known way to undo that is prolonged physical exercise
sequence of activation of fevers
leukocytes release cytokines (released by immune cells) → vagus nerve (& attacks invader) → hypothalamus → ↑ prostaglandins → fever
best treatment for obesity
lifestyle change of increased exercise and decreased eating • sustained not strenuous exercise • important to reduce or eliminate intake of soft drinks
NMDA (*special)
ligand & voltage-gated - need glutamate and depolarization • Ca++ channel
circadian rhythms persist without light but
light is critical for resetting them • Zeitgeber
effective Zeitgeber
light, exercise, arousal of any kind, meals, and environment temperature • Besides light, other zeitgebers have weak effects on their own and work in tangent with light
angiotensin II
like vasopressin, constricts the blood vessels, compensating for the drop in blood pressure and helps trigger hypovolemic thirst (thirst based on low volume)
cognitive symptoms of schizophrenia
limitations of thought and reasoning • difficulty understanding and using abstract concepts → interpret sayings too literally • trouble maintain attention
light's entrainment of the SCN
melanopsin-containing ganglion cells • via the retinohypothalamic path • near nose (so sees towards periphery) • sensitive to average amount of light
semantic memories
memories of factual information • for repeated facts (e.g. guessing famous names when given information about them) • patients who devised own labels for shapes were somewhat successful in remember
amnesia
memory loss
long term memory
memory of events from further back - appears to have several parts • Explicit memory • Implicit memory
short term memory
memory of things that just occurred • not merely en route to LTM → working on memory not just a temporary bin for memory • a way to store memory while working with it
exogenous melatonin: evening dose?
not helpful unless in early evening because at this point body is already producing melatonin
Can you explain how this is consistent with the experience of REM sleep: Decreased dorsolateral prefrontal cortex
not remembering dreams and dreams don't make sense/feel like its not your decision because of this
what type of light helps reset circadian rhythms?
short-wavelength (bluish) light helps to reset circadian rhythms better than long-wavelength light
Can you explain how this is consistent with the experience of REM sleep: Increased parietal and temporal cortex
sight and hearing during dreams
hypothalamus: sexually dimorphic nucleus (SDM)
size of hypothalamus males > females - involved in male sexual behavior (somehow)
patterns of sleep stages
sleep architecture → important to preserve sleep architecture - ~5 cycles per night - SWS → more SWS first half of the night - REM sleep → more REM sleep second half of night - Alcohol changes sleep architecture • Not good to sleep at night because it changes sleep architecture by exaggerating the pattern we have by giving us a lot more SWS early and a lot more REM later • People who sleep like this don't feel refreshed and don't receive cognitive benefits
restoration of body
sleep deprivation is correlated with disease • increased rates of diabetes • rotating shift work- more likely to have diseases • altered immune activity • nurse study- less sleep, increase in cardiovascular disease
Stage 2 Sleep/theta waves
sleep spindles and K-complexes
NREM Sleep
sleep stages other than REM sleep (Stages 1, 2, 3 and 4) - Cycle through these sleep stages in order then after about an hour cycle back from stage four through 3, 2, and then REM • Cycle repeats every 90 minutes - Stages 3 and 4 predominate early in the night but REM occupies an increasing portion of time toward the morning
+ supportive environment
fewer than avg. depressive symptoms
Bupropion
inhibits reuptake of dopamine and to some extent NE but not 5HT
SCN regulates waking and sleeping by controlling
activity levels in other brain areas like the pineal gland
AMPA
- Ligand gated - NA+ channel
combined concentration of all solutes in mammalian body fluids
0.15 M (molar)
steroid hormones
contain four carbon rings
girls exposed to more testosterone in utero
have more preference for boys toys
Semantic memory
meaning, definition
seminal vesicles
saclike structures that store semen
loose associations
thoughts very loosely connected
Disulfiram
(Antabuse) a drug that antagonizes the effects of acetaldehyde dehydrogenase by binding to its copper ion • makes people get sick when they drink alcohol • works for people committed to stop drinking by reaffirming their reason to stop • for those who drink on it, they quit the pill before alcohol
Korsakoff's Syndrome
(aka Wernicke-Korsakoff syndrome) brain damage caused by prolonged thiamine deficiency
energy conservation
(during species time of least efficiency) • fish with no light/dark preference do not appear to sleep • ↓ body temperatures 1-2 degrees C • Postpartum dolphins & newborn dolphins decrease sleeping when there is a need • Grazing animals sleep less than meat-eating animals • animals ↑ sleeping when there is a food shortage
aromatized testosterone in rats
(i.e., estadiol) key in rodent males • once testosterone enters the BBB it is aromatized to estradiol which → masculinizes of the brain
Episodic Buffer
(mental workbench) a temporary, limited capacity store that allows the various components of working memory to integrate information and serves as an interface between working memory and long-term memory - mental workbench → that's why short term memory is also called working memory • where we put stuff so we can work with it • how much you can balance in mental workbench is correlated with IQ
Cause of Korsakoff's Syndrome
(thiamine) B1 deficit → loss of neurons (esp. mammillary bodies) & loss of input (dorsomedial thalamus) to prefrontal cortex
damage in the anterior temporal cortex
- "hub" of information (not sole area of semantic information) - A.M. → BA in engineering, MA in science had a brain infection • Semantic dementia
sleep deprivation corre. with disease/ill-health
- (2005) increased rates of diabetes and impaired glucose tolerance - (night shift workers) increased number of accidents, as well as increased rate of respiratory tract infections, depressed immune function, and cancer - aggravation of hypertension and Type 2 diabetes - altered (increased and decreased) immune activity - (2003) Nurses Health Study • < 5 hrs. sleep corre. with 45% ↑ cardiovascular disease (CVD) risk - Yoked rats study** - fatal insomnia?
3 nurse experiment
- (another w/amnesia): three hospital workers study—which should he approach? • One was mean, one was nice, one was neutral • Person would choose nice nurse out of a lineup to be his caregiver but not know why, just be like "she just looks nice to me"
stress of the mother during pregnancy
- (male rats) ↑ female sexual behavior (in addition to male sexual behavior) - w/alcohol = even less male sexual behavior - possibly via: • stress = ↑ endorphins = interference with testosterone in hypothalamus • stress = ↑ corticosterone = inhibition of testosterone secretion - (humans): correlational study found ↑ stress = ↑ homosexual orientation (but retrospective study)
external genitalia
- 0 to 3 mos.: bipotential precursor - 3-4 mos.: with high level of testosterone exposure changes tissue from on e gender o another • Glans: penis or clitoris • Urethral folds: fuse in male; or become labia minora in female • Lateral bodies: shaft of penis or hood of clitoris • Labioscrotal swellings: scrotum or labia minor
Demographic Data of schizophrenia
- 0.5 percent of people suffer at some point in their life - less common but produces long-term debilitation - more common in cities than in rural areas - immigrants from third-world countries have a higher likelihood of developing schizophrenia • loss of social support could explain • change in diet → diet high in sugar and saturated fat aggravates schizophrenia while diet high in fish alleviates it - more common in men than in women by 7:5 • more severe in men with earlier onset - Overall those with schizophrenia are not violent, except sometimes those with paranoia
Associative features of bipolar disorder
- 1% lifetime prevalence • 2-3% subthreshold • prevalence has been increasing since the 1990s - onset = early 20s - corre. with attention deficits, impulsivity, impairments of verbal memory - males: females, 1:1
postpartum depression
- 20% experience postpartum depression • most recover quickly on own • .1% are serious
birth control?
- disrupts feedback from ovaries to pituitary - no FSH/LH - thickening cervical mucous - inhibit implantation
effectiveness of depression treatments?
- 30% recover with no Tx or with placebo - 20% recover with meds or psychotherapy - few respond to both meds & psychotherapy, few respond to neither • antidepressants: ineffective for those who suffered abuse, neglect, etc. as a child; psychotherapy • antidepressants & adolescents - benefit is greater for the more severely depressed
Treatment for bipolar disorder
- lithium - valproate and carbamazepine
Basal Ganglia - Effect of Danger
Loss of well-learned motor patterns, impaired learning of skills and habits
hypovolemic thirst stimulus
Low blood volume
How are variations in consciousness (e.g., sleep) measured?
Polysomnograph
Why are Antidepressants Effective?
- Antidepressants increase levels of serotonin generally • BUT some people with depression actually have increased levels of serotonin - Antidepressants produce effects on neurotransmitters within minutes to hours • BUT individuals don't feel any mood elevation for at least two weeks - Antidepressants seem to increase BDNF (brain-derived neurotrophic factor) -↑ 5-HT? • but 5-HT effect occurs within hours; depressive symptoms take ~2 weeks - alteration of sleep? → always a decrease in REM -↑ BDNF → neurogenesis in hippocampus and/or cerebral cortex? • every antidepressant increases neuron production; blocking this blocks the benefits
BN continued
- BN resembles drug addiction - recurrent binge • sense of lack of control - recurrent compensatory behavior - 2X/week for at least 3 mos. - self-evaluation is unduly influenced by body weight/shape - not AN - purging (vomit, laxative) vs. non-purging subtype (exercise)
How do you create LTP?
- Baseline → deliver a single impulse to perforant path; measure response in dentate gyrus - LTP induction → deliver high frequency stimulation - Test → deliver single impulse & measure strength of response • Increase in strength of response means that LTP has been successful
Viral infection bipolar disorder
- Borna disease • farm animals: periods of frantic activity alternating with periods of inactivity
viral infection and depression
- Borna disease found in some who were depressed and none of those who were not • unusual reason for depression - also and autoimmune disorder - also associated with other psychiatric disorders
Brain damage in schizophrenia
- Brain damage does not appear to be progressive (but this is debatable) • no proliferation of glial cells (shrinkage of cells?) • some studies show no greater brain abnormalities in older vs. younger patients • others show ↑ brain loss with age • one study found ↑ brain loss during adolescence (maturation)
Atypical Antidepressants
- Bupropion - SNRIs (Serotonin Norepinephrine Reuptake Inhibitors) - venlaxafine - nefazodone
Alternatives to Antidepressant Drugs?
- CBT and other forms of psychological therapy are often helpful - Exercise - Electroconvulsive therapy (ECT) - Transcranial magnetic stimulation - Altered Sleep Patterns - Deep Brain Stimulation
presynaptic changes
- CaMKII → NO • decreased threshold of excitation • increased neurotransmitter release • expands axons • releases neurotransmitter from additional sites
Final outcome varies
- Dendrite builds more AMPA receptors or moves old ones into better positions - Dendritic spines/branching increases - Phosphate groups attach to certain AMPA receptors to make them more responsive than before - Sometimes, the neuron makes more NMDA receptors
Sexual behavior in female humans: menstrual cycle
- FSH is secreted to develop the follicle - Follicle nurtures ovum & produces estrogens - Follicle builds up more FSH receptors; increasing FSH effects on follicle - Follicle increases estraiol secretion - Increased FSH & surger of LH - Ovum is released - Corpus luteum secretes progesterone—prepares uterus & inhibits LH - If egg is unfertilized, then ↓ LH, ↓ FSH, ↓ estradiol, ↓ progesterone - If egg is fertilized, then further ↑ of progesterone & estrogen → ↑ 5-HT3 receptor activity → nausea (30% of women; less risk of miscarriage)
Impaired Storage of Long-term Memory
- HM didn't know the year, his age, and couldn't recognize himself in photos, although he was never surprised by his reflection - Formed a few new weak semantic memories • Semantic memories
HM had
- Intact Working Memory - Impaired Storage of Long-term Memory - Severe Impairments of Episodic Memory - Better Implicit than Explicit Memories - Intact Procedural
receptors for hypovolemic thirst
- Kidneys → measure how much fluid you have - Atria of heart (baroreceptors) → tension increases with more fluid, decreases with less fluid
Genetics of bipolar disorder
- MZ twins: 50% concordance rate - DZ twins: 5-10% concordance rate - Several genes identified, but one determine bipolar disorder
DSM-IV-TR criteria for Major Depressive Disorder
- Presence of single Major Depressive Episode (5 or more for at least 2 weeks; one of 5 must be one of first two) - depressed mood - anhedonia → decreased desire for pleasurable activity - decreased or increased appetite - insomnia or hypersomnia - psychomotor agitation or retardation - fatigue - feelings of worthlessness or guilt - diminished ability to concentrate - recurrent thoughts of death/suicidal ideation • most worried about during treatment because when depressed they don't have the energy to plan/proceed with suicide • when they start having more energy but still feel depressed during early treatment they may be able to find the motivation to plan/go through with suicide
varying levels of REM
- SSRIs which decrease REM do not seem to cause particular detriments - mentally retarded children = ↓ REM - gifted children = ↑ REM - college students during exams = ↑ REM
Raphe Nucelus
- Serotonin → leads to arousal and interferes with REM sleep - ↑ arousal - interferes with REM
LTP shows 3 properties making it an ideal candidate for a cellular basis of learning and memory
- Specificity - Cooperativity - Associativity
short form of 5-HTT...
- Transporters "suck" → move neurotransmitters by uptaking them and moving them - Shorter form is less efficient than normal, longer form - Causes more serotonin → odd because depression is normally associated with high levels of 5-HT • Clearly many causes of depression
Summary
- When glutamate massively stimulates AMPA receptors the resulting depolarization enables glutamate to stimulate nearby NMDA receptors also - Stimulation of the NMDA receptors lets calcium enter the cell, where it sets into motion a series of changes that potentiate the dendrite's future responsiveness to glutamate at AMPA receptors - After LTP occurs, NMDA receptors revert to their original condition - Once LTP has been established, it no longer depends on NMDA synapses
Blind Alleys and Abandoned Mines
- a lot of dead ends to "promising" research
dream research
- according to research, no way to interpret dreams • no way to substantiate meaning or purpose
Medications to Combat Alcohol Abuse
- alcohol is metabolized to acetaldehyde (toxic) by the liver which is then converted to acetic acid by acetaldehyde dehydrogenase • acetic acid is used for energy - those with a gene for producing less acetaldehyde dehydrogenase metabolize acetaldehyde more slowly → produces flushing of the face, increased heart rate, nausea, headache, abdominal pain, impaired breathing, and tissue damage • over 1/3 of people in China and Japan have this gene (alcohol abuse is historically uncommon in these countries)
female rodents
- alpha-fetoproteins bind to estrogen - blocks it from leaving bloodstream - injecting a large dose of estradiol = ↑ masculinization
Species Differences in Sleep
- animals that are equally effective at all times of the day sleep little to none - several species can turn off their need for sleep under certain circumstances • dolphins or whales that just gave birth stay awake 24 hours a day for the first couple weeks while the baby is especially vulnerable without facing harm from sleep deprivation • supports idea that sleep in primarily to conserve energy rather than to fulfill a function that one could not fulfill in other ways - grazing animals that must eat all day sleep less than carnivores that can be satisfied with one meal
two successful evolutionary strategies for men
- be loyal to one woman and devote energies to helping her and her babies - mate with many woman and hope some raise your babies without your help
Periodic Limb Movement Disorder Treatment
- benzodiazepines (e.g., clonazepam) → can control/inhibit movement • addictive
Alzheimer's Disease
- causes memory loss - better procedural than declarative memory - problems result from loss of neurons, malfunctioning neurons, fluctuating levels of arousal - changes increase the older you get
Factors which ↑ or ↓ eating - oral factors
- chewing, swallowing, etc. help us feel more satiated - sham-feeding experiments
circadian rhythms also differ with age
- children go to bed early and wake up early - adolescents start going to bed later and waking up later • occurs all over the world and in many species • apparently due to increased levels of sex hormones - trend beings to reverse after age 20 and adults start going to bed earlier and waking up earlier
male rodents
- circulating testosterone cross BBB; estrogen is blocked by alpha-fetoprotein - testosterone is aromatized into estradiol - masculinization of the brain occurs
- lack of replication for other suspected genes
- consistent with idea that there is no one "schizophrenia" gene - also suggests why schizophrenia does not die out, despite ↓ lifespan and # of children - new mutations in many genes -- microdeletions & microduplications found in 15% vs. 5% of control group -- older fathers = ↑ rate of offspring with schizophrenia
combination pill
- contains estrogen and progesterone to prevent release of FSH and LH - thickens the mucus of the cervix making it harder to a sperm to reach the egg
chemical castration
- cyproterone or medroxyprogesterone (no need to memorize these names) (chemical castration) for sex offenders = varying success with ↓ sexual interest/activity • varied success because testosterone is not the only thing that makes people have sex • negative side effects → - triptorlein (better chemical castration) - note: most sexual offenders have normal levels of testosterone & not all who have high testosterone levels become sexual offenders • testosterone does NOT cause someone to become sex offender
The Hippocampus
- declarative memories, esp. episodic - involved most when you first learn something but usually distributes information out to other locations • every time you think of a memory it's susceptible to being changed
lithium, valproate and carbamazepine...
- decrease the number of AMPA type glutamate receptors in the hippocampus - block the synthesis of a brain chemical called arachidonic acid which is produced during brain inflammation • eating a lb. of seafood per week decreases risk of bipolar disorder
Seasonal Affective Disorder
- depression linked to particular season - more prevalent near poles (longer winter nights) - differs from other types of depression • phase-delayed sleep & temperature rhythms • seldom as severe as major depression - form of depression that occurs during a particular season, such as winter • more prevalent near the pols where the winter nights are longer - have phase-delayed rhythms whereas those with depression have phase-advanced sleep - may have mutated gene controlling circadian rhythms - can be treated with very bright lights
homosexual males vs. homosexual females
- different processes are likely • males discover orientation earlier than females • early femininity corre. with homosexual orientation in males but early masculinity is not corre. with homosexual orientation in females • ↑ bisexualism among homosexual females but not homosexual males
glucose damages
fine blood vessels in extremities and eyes → amputation and blindness risked in untreated diabetes
emotional disturbance
- e.g. flat or labile affect → not showing any emotion - volatile emotions
emotions
- emotions → ↑ (small - moderate) cortisol → enhanced storage & consolidation of recent experiences - too much cortisol → impaired memory
Improving Memory
- enhancing the production of the proteins necessary for LTP may enhance memory • these drugs in humans have had negative side effects - drugs such as caffeine, amphetamine, and methylphenidate somewhat aid memory • moderate doses of stimulant drugs before or after the time of original learning improve the storage of memory by increasing arousal - emotionally stimulating experiences also help by activating the amygdala - herbs like Ginkgo biloba and Bacopa monnieri are not useful though some claim they are • dilates blood vessels → blood flow to brain • mild benefit for those with circulation problems or other disorders • other drugs which ↑ blood flow may have same effect - can alter gene expression in mice to enhance memory • but cause side effects - behavioral methods are the best way to improve memory
The Basal Ganglia
- episodic memory depends on → the hippocampus • develops after a single experience - many semantic memories also form after a single experience - need a different mechanism for gradually learning what probably will or will not happen under certain circumstances; gradual, probabilistic learning • this type of learning depends on → the basal ganglia - nearly all memory tasks activate the hippocampus and basal ganglia to some extent - implicit (muscle) memories, esp. procedural (e.g. learning association of actions & rewards—but over time)
valproate and carbamazepine
- esp. for Bipolar II disorder - How do they work? -- unclear, but... -- ↓ # of AMPA receptors --- excessive glutamate activity = some aspects of mania -- blocks arachidonic acid production - polyunsaturated fatty acids (e.g. seafood)
mild brain anomalies in many other areas
- esp. in those with history of birth complications - great variance among patients - often left temporal and frontal cortical areas (though widespread anomalies) • esp. dorsolateral prefrontal cortex • attention deficits • cell bodies are smaller (esp. in hippocampi & prefrontal cortex) - ↓ thalamus - enlarged ventricles - right planum temporal is equal or larger than left hemisphere - ↓ activity in left hemisphere
Sexual behavior in female rodents
- estradiol then progesterone injection = ↑ sexual behavior • estradiol primes progesterone receptors to be more sensitive
Presynaptic Changes
- extensive stimulation of a postsynaptic cell causes it to release a retrograde transmitter that travels back to the presynaptic cell to modify it -- retrograde transmitter is often → NO -- as a result, a presynaptic neuron --- decrease its threshold for producing action potentials --- increases its release of neurotransmitter --- expands it axon --- releases its transmitter from additional sites along its axon - LTP reflects increased responsiveness by the presynaptic AND postsynaptic neurons
time and consolidation
- fMRI scans → recent famous people (vs. earlier ones) = ↑ activation of brain areas - fMRI scans → recent autobiographical info (vs. earlier ones) = ↑ activation of brain areas - implication is unclear → did earlier memories consolidate or were they more strong to begin with?
Major Depressive Disorder
- feel sad/helpless most of the time all day everyday - don't enjoy things, lack energy, feel worthless, contemplate suicide, have trouble sleeping, can't concentrate - nucleus accumbens is less responsive to rewards - ~5% of adults in the US have depression at all times - more common in adults than in children, but more persistent in children - after age 14, becomes more prevalent in women - more common to have episodes of depression separated by normal mood rather than lifelong depression • first episode of depression → generally longer and triggered by a highly stressful event
internal sex organs
- fertilization - 6 weeks = primordial gonads in both - 6 weeks = SRY gene causes secretion → H - Y antigen → medulla into testes (otherwise, cortex → ovaries) - 3 mos. In males • testosterone → development of Wolffian system (vas deferens, seminal vesicles) • Müllerian-inhibiting substance → degeneration of Müllieran system (uterus, Fallopian tubes, vagina) so that the Wolffiam duct system can become dominate
How Effective Are Antidepressants
- for many, finding an effective antidepressant is a trial and error process and takes a long time • because it can take so long, it is unclear whether the antidepressant medication is actually effective or whether the depressive episode simply ended - drugs are only moderately helpful for some and not helpful at all for many
depressed people sleep
- wake up early - enter REM w/in 45 min. of sleep (phase-advanced) - ↑ eye movements during REM - relatives: sleep issues and ↑ risk of depression
people with Down syndrome almost invariably get Alzheimer's if they live into middle age
- found genes linked to many cases of early-onset Alzheimer's on chromosome 21 (the chromosome doubled in those with Down) • genes cause a protein (amyloid-β) to accumulate inside and outside neurons
Genetics
- genetic contribution of unknown size - related to homosexual male, then... • MZ twins: 52% probability • DZ twins: 22% probability • adopted brother: 11% (vs. 2-6% in general population) -what's the implication? - related to homosexual female, then... • MZ twin: 48% probability • DZ twins: 16% probability • adopted sister: 6% - Environmental factors? • parenting style?
Sleep Apnea results from several causes
- genetics, hormones, old-age deterioration of the brain mechanisms that regulate breathing - obesity, especially in middle age men • many obese men have narrower than normal airways so much breathe frequently or vigorously but this breathing pattern cannot be kept up during sleep and is worsened by increasingly narrow airway caused by sleep posture
Where are steroids released from?
- gonads • testes • ovaries - adrenal cortex (small amounts of androgen) - difference between the sexes? • Not types of hormones but varying ratios
Habituation in Aplysia
- habituation: a decrease in response to a stimulus that is presented repeatedly and accompanied by no change in other stimuli • in aplysia, depends on a change in the synapse between the sensory neuron and the motor neuron - mild, repeated stimulation → (somehow, synaptic change) e.g. ↓ neurotransmitter release → ↓ strength of response
CAH girls (XX) genitals?
- hermaphroditism • true hermaphrodite = rare • most are pseudohermaphrodites aka intersex • 1 in 100 = some degree of ambiguity • 1 in 2,000 = very ambiguous
Analogous to Sleep: Hibernation
- hibernating animals decrease their body temperature to only slightly above that of the environment without freezing their blood - heart rate drops to almost mothering, neuron cell bodies shrink, dendrites lose a fourth of their branches (replaced when body temperature returns) - hibernation is a period of relative invulnerability to infection and trauma
Tuberomammillary nucleus
- histamine pathway → enhances arousal and alertness throughout the brain • antihistamine drugs that cross the BBB cause drowsiness but those that do not cross the BBB avoid this side-effect
Brain Anatomy
- homosexual men are shifted partly in the female-typical direction for some brain structures but not others and vice versa for homosexual women - straight men have INAH-3's 2x larger than straight women • gay men have smaller INAH-3's like straight women - normally: bed of nucleus of stria terminalis (BNST): males > females - transsexuals (male): BNST is as small as a female's
(REM) brain development?
- immature vs. mature brain (postnatally) - newborn: 70% - 6 mos.: 30% - 8 yrs.: 22% - late adulthood: 15%
Discrepancies of Sexual Appearance
- in places with a lot of inbreeding (Dominican Republic) some fail to produce the enzyme that turns testosterone to dihydrotestosterone leading to masculinized brains but not masculinized external genitalia • raised as girls then at puberty see genitals become male and switch to males sexually o brain has always been male - hormones don't have complete control but neither do rearing patterns
Body has four water stores
- intracellular (67%) → osmotic thirst - extracellular • intravascular fluid (7%) → volumetric thirst • cerebrospinal fluid (<1% • interstitial fluid (26%)
low card diet
- ketosis - ketoacidosis
XY male with SRY mutation?
- lack of masculinization - from poorly developed male genitals to becoming female (ducts, genitals, brain)
Mid Brain Abnormalities
- less than average gray and white matter - larger than average ventricles - smaller hippocampi - weaker than average connections in the dorsolateral prefrontal cortex - slightly larger left hemisphere
phencyclidine (PCP) (inhibits NMDA receptors ) =
- low doses: intoxication, slurring - higher doses: ↑ positive & negative symptoms (including memory loss) - not in prepubertal - results in long-lasting relapse in those who have recovered from schizophrenic episode (but only temporary effect in those w/o schizophrenia history) - glycine (indirect NMDA & metabotropic glutamate agonist) increases effects of other antipsychotic meds (esp. for negative symptoms) -- glutamate is not used b/c of overexcitation issues -- glycine (mice) = ↓ response to PCP
Lashley searched for engrams in many ways
- made knife cuts in various locations of rat's brains → no effect - removed large portions of the cortex • deficits had more to do with how much of the brain was removed than on where the tissue was removed from
although warmer is better, we stay at 98 to 100 F because
- maintaining a higher temperature requires more fuel and energy - beyond 105 F proteins begin to break their bonds and lose their useful properties
Genetics and Other Causes
- many genes linked, but none found in a high percentage in those with autism - result from mutations or microdeletions - topoisomerases → enzymes that regulate the repair and replication of DNA and the production of certain types of RNA • autism is a common result of mutation to topoisomerase gene - prenatal environment • mothers have certain antibodies that attack certain brain proteins (may make chemical intervention possible) - folic acid (vitamin b9)
XX but translocated SRY gene
- masculinization - e.g., 1 ovary + 1 testis (rare); 2 testes; mixed testicle & ovarian tissue on both sides (also rare)
CAH girls brain
- masculinization - toy/play preference • boys - CAH girls - girls - preference of magazine (sports. vs. glamour) • boys - CAH girls - girls - BUT female gender identity • gender identity vs. masculinity
Adopted Children Who Develop Schizophrenia
- may be genetic from the birth mother but also environmental due to choices made by the mother during pregnancy - risk increases if adopted family is severely disordered - adopted children = more like biological parents (e.g. 12.5% schizophrenia among immediate biological relatives vs. none of adoptive relatives)
Differences in Jealousy
- men are usually more jealous because having unfaithful women decreases the certainty that her children are his - toleration of infidelity by husbands and resultant jealousy vary by culture • no known society considers infidelity more acceptable for women than for men - men say more jealous due to sex, women say more jealous due to emotion but in reality both are more jealous due to emotion - males → in terms of sexual infidelity because it matters if women are with more people because man might not be able to know paternity - females → more emotional because want man to want to give resources to you
when do men discover homosexuality
- men typically discover this earlier than women • feminine behaviors in childhood and adolescence are strong predictors of homosexuality in males but masculine behavior in girls is a poor predictor of homosexuality in females
Depression genetics
- moderate degree of heritability; no single gene identified - depression may be a combination of syndromes as those with depression have family members with many other disorders - serotonin transporter gene → short and long type -- those with two of the short genes → increasing numbers of stressful events led to a major increase in the probability of depression --- magnifies the reaction to stressful events
onset of symptoms after age 60-65 is vastly more common and is caused by many genes
- most influential gene controls a chemical called apolipoprotein E which helps remove β-amyloid from the brain - abnormal proteins → misfolding & aggregation → interferes with cell function -- Aβ42 (instead of Aβ40) leads to amyloid plaques (extracellular) --- likely the cause --- amyloid plaques primary drive for symptoms - abnormal tau protein (intracellular) leads to neurofibrillary tangles -- along with Aβ42 = symptoms
Early Development and Later Psychopathology (schizophrenia)
- movement abnormalities in infancy - dorsolateral prefrontal cortex is one of the slowest areas to mature so problems may not show until matured (early adulthood)
indus dolphins
- never stops swimming - brief 4-60 sec. naps with half a hemisphere at a time - bottle nose dolphins & porpoises
low-carb vs. low-fat diet
- with decreased amount of fats taken in, increases risk of violent death (statistically significant correlation) - fat needs to be part of diets in small amounts - low-carb good for you and associated with weight loss • whole 30, atkins, southbeach diet
Treatment for Autism spectrum disorder
- no medical treatment helps with the central problems • a second-generation antipsychotic drug can sometimes help with the stereotypes behaviors (serious side effects) - behavioral treatments address the deficits in social behavior and communication • focus on eliciting a child's attention and reinforcing favorable behaviors (successful for many children but not all) • treatments for stereotyped behaviors → reinforcing other behaviors or competing behaviors - fad treatments often become popular because parents are disappointed with current treatment • waste of time and money
genes and schizophrenia
- no single gene implicated though - those with schizophrenia and their siblings have few children -- so new cases may come from new mutations or even more probably micro deletions --- microdeletions are more common in those with schizophrenia than others
Prementrual dysphoric disorder (previously PMS)
- normally: ↓ estradiol, ↓ progesterone, ↑ cortisol (right before menstruation) - PDD: same or weaker fluctuations - evidence of abnormal metabolism of progesterone (↓ metabolism)
Schizophrenia Diagnosis
- originally called dementia praecox → premature mental deterioration - according to DSM-5 must have -- deteriorated everyday functioning for at least 6 months -- must also have at least two of the following with one from the first three: --- delusions --- hallucinations --- disorganized thought --- grossly disorganized behavior --- weak or absent signs of emotion, speech, and socialization
Long-term Course of schizophrenia
- outcome varies - up to 25% show serious disorder throughout life - 10-20% may experience an episode an recover on their own
What Patients with Amnesia Teach Us
- people do not lost all aspects of memory equally - people have several somewhat independent kinds of memory that depend on different brain areas
Oral Factors
- people like to eat; they like to taste and chew even when they're not hungry • people who fed themselves with a tube everyday so they could not taste or chew felt unsatisfied and reported a desire to taste or chew something - Sham-feeding experiments
The Hippocampus and Spatial Memory
- place cells & spatial view cells • place cells • spatial view cells - people figuring out best route to a friend's = ↑ hippocampus activity - when rats learn to perform certain tasks in a particular order at particular times, may hippocampal cells respond at a particular time - London Taxi drivers hippocampi - Radial maze - Morris Water maze
Brain Structures of Arousal and Attention
- pons - Hypothalamus
Environmental Influences on addiction
- prenatal environment contributes to the risk for alcoholism -- pregnant mother drinking increases risk that child will develop alcoholism - childhood environment -- children with less sensitive form of GABA receptors → more impulsive --- careful parental supervision makes these kids less likely to develop impulse problems though
PER and TIM proteins
- promote sleep and inactivity - concentration of these proteins oscillates over a day based on feedback information among neurons - in addition to automatic feedback, light activates a chemical that breaks down TIM
Electroconvulsive therapy (ECT)
- quick, electric shock to head that most people don't remember - every other day for ~2 wks - usually just perform on one hemisphere because can result In brain damage • right hemisphere because people with depression often increased right hemisphere activity so decreasing it is though to help depression - abused in the 1950s before antidepressants - now used for those with severe depression who do not respond to drugs - most common side effect → memory impairment lasting a few months - quick results (in 1 week) BUT high risk of relapse - increases proliferation of new neurons in the hippocampus - How does it work? • perhaps alters gene expression of neurotrophic factors, arachidonic acid, neurogenesis in hippocampus, responsiveness to exercise • relapse is an issue
Sexual behavior (in male rodents)
- removal of testes = ↓ sexual behavior - testosterone injection + castrated male = ↑ sexual behavior - testosterone metabolites (dihydrotestosterone or estradiol) injection = ↑ sexual behavior - Other factors: e.g., experience, dominance status • Monkeys have social hierarchy and researchers discovered head monkey had more sex even when castrated
Functions of Sleep
- rest our muscles, decrease metabolism, perform cellular maintenance in neurons, reorganize synapses, and strengthen memories - people who don't get enough sleep react more severely than average to stressful events
exercise and obesity
- with dieting • especially for women - men don't need dieting as much as women; can lose weight just with exercise
Prenatal and Neonatal Environment - Low Risk Factors
- risk for schizophrenia elevated in those who had problems that could have affected brain development -- poor nutrition of the mother during pregnancy -- premature birth -- low birth weight -- complications during delivery - if mother is exposed to extreme stress early in pregnancy or has prolonged illness - head injuries in early childhood - if mother is Rh-negative and baby is Rh-positive mother's immune system may reject baby -- increases with number of children had, stronger for boys than girls -- Season of birth effect
Reasons for sleep
- safety from predators - restoration of body - restoration of mind - energy conservation
several physiological mechanisms increase your body heat in a cold environment
- shivering → small muscle contractions that generate body heat - decreased blood flow to the skin → prevents the blood from cooling too much - fluffing out fur → increases insulation • only helpful for mammals not humans but we do get goose bumps as a result of this vestigial response
evidence supporting distinction between STM and LTM
- short term and long term memory differ in their capacity • short term memory → about 7 things • long term memory → vast capacity - short term memory depends on rehearsal whereas long term memories can be reconstructed after many years, though not always 100% accurately • consolidation - once you forget something in short term memory, it is lost, but a hint may help you reconstruct a forgotten long term memory
↑ testosterone → ↑ NO → ↑ hypothalamus → ↑ blood flow into penis
- sildenfil (Viagra) = ↑ NO - also causes erect clitoris
other sleep alterations
- sleep at an earlier time • to ↓ depressogenic substance - deprive REM sleep (selective sleep deprivation)
treatment for narcolepsy
- sleep attacks → stimulants (e.g., methylphenidate, catecholamines) • hard on cardiovascular system • (i.e. Ritalin) that enhance dopamine and norepinephrine activity - REM issues → antidepressants (↑ 5-HT & NE) • Increase serotonin to decrease REM issues because they decrease REM sleep
Evidence for Restoration of the Body
- sleep deprivation corre. with disease/ill-health
evidence against sleep for restoration of the body
- sleep deprivation does not result in exercise deficits • not completely true in elite athletes - healthy subjects in bed for 6 weeks did not have decrease sleep needs
Sleep and Memory
- sleep improves memory - if you learn something then sleep your memory becomes better - sleep also helps people reanalyze their memories - patterns in the hippocampus that occur during sleep resemble those that occur during learning except they're more rapid during sleep - to prevent runaway overactivity as you learn more information, your brain compensates for strengthening some synapses by weakening or removing others, mostly during sleep
Treatment of insomnia
- sleeping pills → can cause dependence and inability to sleep without the pills • benzodiazepines - teaching good sleep hygiene - melatonin
Circadian rhythms differ among people
- some awaken early, reach peak productivity early and become less alert later in the day - some warm up more slowly, reaching their peak in the late afternoon or evening, tolerating staying up all night better than morning people do • most people are intermediate between the two extremes
evidence AGAINST energy conservation
- some dolphins and sharks swim during sleep - (human) brain metabolism during NREM and during REM
childhood onset schizophrenia
- some genes for childhood-onset (rare) identified • but different from adult-onset
Hunger
- species differ in eating strategies - humans neither limit their diet like small birds nor stuff themselves like bears but are more like bears than birds • has led to obesity epidemic - use learned and unlearned mechanisms to choose the foods we eat
Mechanisms of Water Regulation
- species differ in their strategies for maintaining water (a lot based on habitat) - humans vary strategy depending on circumstances
Effects of CaMKII and CREB are magnified by
BDNF → brain-derived neurotrophic factor - Persistent activity at synapses lead to action potentials that start in axons but back-propagate into the dendrites which then release BDNF
Abnormalities of Hemispheric Dominance and depression
- strong relationship between happy mood and increased activity in the left prefrontal cortex - most with depression have decreased activity in the left prefrontal cortex • seems to represent predisposition rather than reaction - ↑ right hemispheric activity • those with depression = ↓ left hemisphere activity & ↑ right hemisphere activity • left hemisphere damage = many become seriously depressed • right hemisphere damage = fewer depressed, some even become manic
Leptin
- taste, stomach distension, duodenum distension, and insulin help regulate the onset and offset of a meal - people though may over or under-eat day-to-day so the body needs a long-term mechanism to compensate for day-to-day mistakes • does so by monitoring fat supplies • the more fat cells, the more leptin
Delayed Matching-to-sample task and Delayed Nonmatching-to-sample task
- tests declarative, possibly episodic memory - hippocampal damage → impaired performance (sometimes) - basal ganglia can take over this task (so that it is no longer a declarative task) • Can learn through redundancy too • When one memory system fails, another memory system can compensate for that because they all work together
Researcher's found Lashley's conclusions rested on two unnecessary assumptions
- that the cerebral cortex is the best or only place to search for an engram • Lashley didn't consider that subcortical regions of the brain could be important in - that studying one example of learning is just as good as studying another one
Family Studies and schizophrenia
- the more closely biologically related you are to someone the greater your own probability of schizophrenia - MZ twins have a sum higher concordance for schizophrenia than DZ twins -- 48 concordance in MZ twins -- discordant MZ twins: offspring have same rate of schizophrenia—what does this tell you? --- Both twins have the gene and are passing it on, MEANING some environmental factor must have caused one to develop and one not to
Since most young people are evening people, school schedules put them at a disadvantage
- the most evening people get lower than average grades despite having average or above-average intelligence • suffer "social jet-lag" everyday • also more likely to use alcohol, overeat, and engage in other risky behaviors
Altered Sleep Patterns
- those with depression have sleep problems that generally precede the mood change - sleep patterns resemble those who have western jet lag - people with depression who stay up all night have briefly relieved depression the next day • sleep deprivation causes astrocytes to release adenosine which has antidepressant effects - altering sleep schedule to go to bed earlier than usual and wake up earlier can temporarily relieve depression but circadian rhythms shift again making depression return
Sensitization in Aplasia
- traced to changes in identified synapses in aplasia -- strong stimulation on the skin excites a facilitating interneuron that releases 5-HT onto the presynaptic terminals of many sensory neurons --- block potassium channels in these neurons, meaning repolarization takes longer than usual, so neurotransmitters are released for longer than usual - intense stimulation → facilitating interneuron → 5-HT onto the terminal buttons of sensory neurons → closing K+ channels → prolonged action potentials (for later stimulations) → ↑ neurotransmitter release → ↑ strength of response
What Men and Women Seek in a Mate
- varies from culture to culture reflecting more learned than genetic behavior
non-sexual effects of estrogen
- ↑ dendritic spines (hippocampus) - also ↑ D2 receptors & ↑ 5-HT2A receptors in several brain areas
When the ventromedial hypothalamus plus (so the VMH plus some of the area surrounding it) is damaged this area, you get:
- ↑ insulin production → ↑ storage of fats • overeating UNTIL significant weight gain - finicky eater - sweets • ↑ stomach motility → stomachs empty faster • ↑ frequency of meals (not meal size)
Parental behavior (in rats) - Females • How do the hormones work to ↑ maternal behavior?
- ↑ sensitivity of estrogen receptors (for only those areas involved with maternal behavior) → ↑ attention to young - ↑ activity in medial preoptic area & ↑ anterior hypothalamus → ↑ maternal behavior
effects of sleep deprivation
- ↑ sleepiness, irritability, impaired concentration, impaired performance esp. on cognitive & vigilance tasks, "microsleeps," hallucinations (even - risk of accidents may ↑ - (SWS) destruction of free radicals?
Neurotransmitters and depression
- ↓ monoamines (DA, NE, 5HT), esp. 5-HT? -- tryptophan depletion diet = brief bout of depression in those with history of depression --- how do you deplete tryptophan through diet? -- yet sometimes ↑ 5-HIAA (metabolites) in those with depression - must be on medication for 2-3 weeks to start seeing symptom relief even though changes the levels of NT within hours, suggesting NT is not the only cause
associative features of schizophrenia
1% prevalence - declining rates - less severe cases - 10-100X more common in US &Europe than in most 3rd world countries -- diet in US = ↑ fat + sugar = worse -- diet in 3rd world country = ↑ fish = alleviates -- more social support in 3rd world countries - acute vs. chronic - IQ: usually a few points less than avg. US - lifetime prevalence -- males (7): females (5) -- males: earlier onset, more severe -- females onset around 30s/40s, menopausal - usually prognosis is better but not always -- male brains release more DA
hypovolemic thirst Receptor location
1. receptors measuring blood pressure in the veins 2. subfornical organ, a brain area adjoining the third ventricle
Sleep spindles
12 to 14 Hz brain waves in bursts that last at least half a second - Result from oscillating interactions between cells in the thalamus and cells in the cortex - Correlated with IQ
sensitive period
1st trimester for humans - during this time, sex hormones determine whether the body develops female or male genitals
women have depression ...
2:1 to men starting from puberty on, which encouraged researchers to look at sex hormones because women have more sex hormones and the discrepancy occurs at puberty
Yoked rats study
87% reduction in sleep → unable to control body temperature, very high metabolism, death in about 2 weeks • every time they fall asleep, platform rotates- wakes them up- 87% reduction • other group, platform rotate when partner's platform rotates- 10% reduction • first group- all died • something vital about sleep • 2 week sleep deprivation in rats=2 years for humans • World Record- 15 days awake
periovulatory period
= ↑ initiation of sex estrogen likely, also possibly testosterone - ↑ pleasantness rating of erotic film - ↑ ability to categorize male vs. female photos - prefer masculine faces ... • for short-term sex • for creating ideal mate picture • when choosing between two males (via videotape description)
Osmotic thirst Hormone influences
Accompanied by vasopressin secretion to conserve water
self-generated rhythms
your body spontaneously generates its own rhythm of wakefulness and sleep
biological clock
Brain generates its own rhythms insensitive to most forms of interference
Learning vs memory
But the differentiation is not clear-cut
Hippocampus and Cerebral Cortex - One trial or many?
Can learn in a single trial
Nature vs. Nurture?
David Reimer ↓ 5-α-reductase 2 - Dominic Republic & other areas (esp. with inbreeding) - converts testosterone into dihydrotestosterone - genitals? • ambiguous genitals → reared as girl - puberty? • another enzyme converts testosterone into dihyrotestosterone → growth of penis & scrotum - most then lived as a boy • why might this be okay?
Effect of lesion on Lateral preoptic area
Deficit in osmotic thirst due partly to damage to cells and partly to interruption of passing axons
Effect of lesion on Preoptic area
Deficit in physiological mechanisms of temperature regulation
mechanisms may be involved with LTP induction
Different mechanisms may be involved with LTP induction in different brain areas
Characteristics of Stage 1 & sometimes Stage 2
Feel like you "haven't been asleep"
Factors which ↑ or ↓ eating - glucose
Fluctuation → not as large as you think because body is very good at regulating glucose in blood; but small fluctuations will cause body reactions (hunger, insulin)
sometimes LTP depends on changes at
GABA synapses
Hippocampus and Cerebral Cortex Learns based on what type of feedback?
Generally explicit, describable in words
Basal Ganglia Learns based on what type of feedback?
Generally implicit; often not possible to describe what's learned in words
Basal Ganglia Produces:
Habits
Hippocampus and Cerebral Cortex - Effect of Danger
Impairs declarative memory, especially episodic memory
Importance of sleep
Important even in animals where it would be more adaptive to NOT sleep
hypovolemic thirst Hormone influences
Increased by angiotensin II
Effect of lesion on Ventromedial hypothalamus
Increased meal frequency, weight gain, high insulin level
Effect of lesion on Paraventricular nucleus
Increased meal size, especially increased carbohydrate intake during the first meal of the active period of the day
Basal Ganglia - One trial or many?
Integrates information over many trials
as learning proceeded
LIP cells responses increased
at the start of training
LIP cells showed little response to tone
Hippocampus and Cerebral Cortex Produces:
More flexible responses
By what do most try to set their sleep-wake cycles?
Most try to set their sleep-wake cycles by the clock, but sunlight still has influence - Spring Forward Daylight Savings Time → most people feel ill-rested for days even when they go to bed at their same bed time - Germany has a 30 minute sun difference but is in the same time zone • Those on the eastern side have sleep midpoints 30 minutes earlier than those on the west side because of the light - More than 50% of blind people report frequent sleep problems
male and female mammals both start with
Mullerian and Wolffian Ducts and undifferentiated gonads
The testes also produce
Mullerian-inhibiting hormone (MIH) which causes the Mullerian ducts to degenerate and finally result in the development of penis and scrotum
Osmotic thirst Receptor location
OVLT, a brain area adjoining the third ventricle
REM sleep is associated with
PGO waves
DSM-IV-TR criteria for Bipolar Disorder
Presence of at least one manic episode: - elevated mood for at least 1 week AND - three or four (if only irritability is present) of the following: • grandiosity • decreased need for sleep (e.g. 3 hours) • more talkative • thoughts are racing • distractibility • increase in goal-directed activity or psychomotor agitation • excessive involvement in pleasurable activities (to the point where negative things can occur)
Intact Procedural Memory
Procedural memory - the development of motor skills and habits; a special kind of implicit memory
Memory
Process by which the information is encoded, stored, & later retrieved (Kandel, Schwartz, & Jessell, 2000)
Learning
Process by which we acquire information
REM & SWS
REM & SWS - sleep after deprivation = rebound effect (more REM and more SWS than usually to make up for it but NOT more of stages 1 and 2) - SWS more tightly regulated - deprivation leads to greater insistence
one hypothesis of the function of REM sleep
REM is important for memory storage, especially for weakening the inappropriate connections • however those taking antidepressants which decreases REM sleep do not have memory impairments
another hypothesis of the function of REM sleep
REM shakes the eyeballs back and forth enough to get sufficient oxygen to the corneas of the eyes because the corneas unlike the rest of the body get oxygen directly from the surrounding air so they deteriorate slightly during sleep because they are shielded from the air • shaking the eyes moves the fluid behind the eyes so they can get oxygen from them • makes sense that REM then occurs more toward the end of the night when the fluid behind the eyes would be most stagnant • however those taking antidepressants which decreases REM sleep do not have cornea damage
So how is REM affected when people take Prozac, Paxil, etc?
REM sleep is decreased but the pills still treat depression, etc
Females do not have the
SRY gene so their gonads develop into ovaries not testes and their Wolffian ducts degenerate
Parental behavior (in rats) - Females • 1st few days hormones play a role in maternal behavior, then experience makes maternal behavior in latter days—why is hormone no longer needed?
Smell of infant mice/rats causes increased in maternal aggression so need hormones early on to overcome urge to hurt the offspring; become desensitized to smell after a few days so hormones aren't needed
Narcolepsy
a condition characterized by frequent periods of sleepiness during the day with four main symptoms that can be interpreted as intrusions of a REM-like state into wakefulness; Irresistible attacks (could happen quickly or more gradually) of refreshing sleep that occur daily over at least 3 mos. - 4 main symptoms - total sleep time = normal - sleep quality = normal - genetic influence - caused by problems with orexin
hypovolemic thirst Best Relieved by Drinking
Water containing solutes
Androgens cause
Wolffian ducts to develop into seminal vesicles and the vas deferens
Short- and Long-Term Regulation of Feeding
Your brain gets messages from your mouth, stomach, intestines, fat cells, and elsewhere to regulate your eating
men's testosterone level decreases and his prolactin level increases after
a baby is born, especially the longer he spends with the child • correlational not causational data
Inhibitory transmitters are
a combo of GABA, neuropeptide Y, and agouti-related peptide (AgRP)
Bulimia nervosa
a condition in which people alternate between binges of overeating and periods of strict dieting - many but not all induce themselves to vomit - 95% with BN also suffer depression, anxiety, or other emotional problems - 1.5% of US women and 0.5% of US men develop BN at some point in their life - become more common every generation
Brain death
a condition with no sign of brain activity and no response to stimuli
cloacal exstrophy
a defect of penis development but otherwise normal levels of testosterone - nearly all these men surgically changed to and reared as girls develop more masculine and want to be turned back to male • also sexually attracted to women
differential diagnosis
a diagnosis that rules out other conditions with similar symptoms
obesity in the US is considered
a disease • makes people feel less guilty for obesity • also could make people quit trying to lose weight because they believe they can't
Jet Lag
a disruption of circadian rhythms due to crossing time zones - travelers complain of sleepiness during the day, sleeplessness at night, depression, and impaired concentration; biological clock is out of sync with environmental clock • problems stem from mismatch between internal circadian clock and external time
Activation synthesis hypothesis
a dream represents the brain's effort to make sense of sparse and distorted information - dreams begin with bursts of spontaneous activity in the pons (PGO waves) that activate some parts of the cortex but not others - the cortex combines this haphazard input with whatever other activity was already occurring and does its best to synthesize a story that makes sense of the information - criticized for being vague - PGO waves- interpret brain activity - activity of the pons
chlorpromazine
a drug discovered in the 1950s that relieves the positive symptoms of schizophrenia for most but not all people • tardive dyskinesia
antagonist
a drug that blocks a neurotransmitter to inhibit transmission
agonist
a drug that mimics or increases drug effects to facilitate transmission
vas deferens
a duct from the testes into the penis
Prader-Willi syndrome
a genetic condition marked by mental retardation, short stature, and obesity - 4-5x higher levels of blood ghrelin - perhaps inability to turn off ghrelin release
Melatonin
a hormone released by the pineal gland that influences both circadian and circannual rhythms - Secreted mostly at night • Secretion starts to increase 2-3 hours before bedtime • ↑ sleepiness
Aldosterone
a hormone that causes the kidneys, salivary glands, and sweat glands to retain salt and is produced by the adrenal glands when the body's sodium reserves are low - Combines with angiotensin II to change the properties of taste receptors on the tongue, neurons in the nucleus of the tractus solitarius, and neurons elsewhere in the brain to increase salt intake
cholecystokinin (CCK)
a hormone that limits meal size in two ways • constricts the sphincter muscle between the stomach and the duodenum causing the stomach to hold its contents and fill more quickly • stimulates the vagus nerve to send signals to the hypothalamus causing cells there to release a neurotransmitter that is a shorter version of the CCK molecule itself
Red nucleus
a midbrain motor area that recieves input from the cerebellum
Bipolar Disorder
a mood disorder in which people alternate between two poles, depression and mania - onset in teenage years/early 20s - 1:1 men to women, BUT men are more likely to have sever (bipolar I) cases while women are more likely to get treatment
mania
a mood state characterized by restless activity, excitement, laughter, excessive self-confidence, rambling speech, and loss of inhibitions
insulin
a pancreatic hormone that enables glucose to enter the cells, except for brain cells, where glucose does not need insulin to enter - glucose entry into cells - stimulates glycogenesis - diabetes I and II (high levels of insulin, but cells not longer accept insulin)
Glucagon
a pancreatic hormone that stimulates the liver to convert some of its stored glycogen back to glucose - stimulates glycogenolysis → breaks down sugar - then lipolysis → breaks down fat - then gluconeogenesis (protein) → breaks down protein
menstrual cycle
a periodic variation in hormones and fertility over the course of 28 days that occurs due to the interaction between a woman's hypothalamus and pituitary with the ovaries
Deep Brain Stimulation
a physician implants a battery-powered device into the brain to deliver periodic stimulation to certain brain areas shown to decrease depression when activity is increased
Long-term depression (LTD)
a prolonged decrease in response at a synapse, occurs for axons that have been less active than others • compensatory process → as one axons strengthens, another weakens
Alpha-fetoprotein
a protein in rodents that binds with estradiol and prevents it from entering cells where it could produce masculinizing effects
Blue-wavelength light
actives melanopsin-containing ganglion cells and is found in computers, tvs, phones, etc. • using these devices late at night can make sleep more difficult
Autism spectrum disorder
a range of disorders with various degrees of difficulty - much more common in boys than girls - includes -- deficits in social and emotional exchange -- deficits in gestures, facial expressions, and other nonverbal communication -- stereotypical behavior, such as repetitive movements -- resistance to a change in routine -- unusually weak or strong responses to stimuli such as indifference to pain or a panicked reaction to a sound - some parents notice problems in infancy, develops in other children - many with autism tend to be very skilled at detecting visual motion -- develop narrow skills at which they excel
K-complex
a sharp brain wave associated with temporary inhibition of neuronal firing
obesity can sometimes be traced to
a single gene - mutated gene for the receptor melanocortin, a neuropeptide important for satiety • those with mutation overate and become obese from childhood onward
Set point
a single value that the body works to maintain - Mechanisms maintain set points of blood levels of water, oxygen, glucose, sodium chloride, protein, fat, calcium, and acidity
Periodic Limb Movement Disorder
a sleep disorder characterized by repeated involuntary movement of the legs and sometimes the arms during sleep - mostly in middle age to older people - leg kicks every 20 to 30 seconds for minutes or hours mostly during NREM sleep - associated with restless leg syndrome but NOT the same thing • restless leg syndrome is all day; feel like you have a tingling or a bug on your leg that makes you want to move your leg - often affects partners more than individuals
Retinohypothalamic path
a small branch of the optic nerve that goes from the retina to the SCN and alters the SCN's settings - input to this path does NOT come from normal retinal receptors • mice with almost no rods or cones still reset biological clocks in synchrony with the light
Locus Coeruleus
a small structure in the pons that is usually inactive, especially during sleep, but that emits bursts of impulses in response to meaningful events, especially those that produce emotional arousal - axons release norepinephrine widely throughout the cortex • Norepinephrine → - increases the activity of the most active neuron and decreases the activity of less active neurons resulting in enhanced attention to important information and enhanced memory
Retinohypothalamic path input, instead, comes from
a special population of retinal ganglion cells that have their open photopigment called melanopsin • these cells receive some input from rods and cones but even without this input they respond directly to light • located mainly near the nose, from which they see toward the periphery • respond to overall average amounts of light, NOT to spontaneous changes in light and mainly to short-wavelength (blue) light
sleep
a state that the brain actively produces, characterized by decreased response to stimuli • person can be woken up by certain stimuli
Alpha waves
a steady series of brain waves at a frequency of 8 to 12 per second that are characteristic of relaxation NOT all wakefulness
Reticular Formation
a structure that extends from the medulla into the forebrain (esp. pontomesencephalon) - axons of reticular formation neurons reach into both the brain and the spinal cord • those descending into the spinal cord form part of the medial tract of motor control - acetylcholine, glutamate → particularly secreted by reticular formation which leads to arousal - Pontomesencephalon
Hebbian Synapse
a synapse that increases in effectiveness because of simultaneous activity in the presynaptic and postsynaptic neurons; persistent strengthening of a synapse; a case where simultaneous activity in the presynaptic (A-C connection) and postsynaptic neurons (C-B connection) result in strengthening of this synapse - cells that fire together wire together
men have a stronger preference for
a younger partner • young women remain fertile longer
thought disorder likely due to
abnormal connections between cortex, thalamus, & cerebellum - may give rise to psychotic symptoms • e.g. overtaxing working memory in non-schizophrenic people can result in incoherent speech - inverted hollow mask
destruction of basal forebrain in those with alzheimers
acetylcholine processes impaired
when leptin levels are high, you
act as if you have plenty of nutrition, eating less, becoming more active, and increasing the activity of your immune system • also activates the sympathetic nervous system and increases blood pressure
female mice injected with testosterone
act more male and have enlarge clitorises
(cold) AH/POA
activation of posterior hypothalamus which then > stimulates brainstem motor area > resulting in involuntary contraction of muscles (i.e. shivering). Also, increases NE release to cause vasoconstriction
place cells
active depending on what place your body is; where you are located in place or space
slight amounts of cortisol and epinephrine
active the amygdala and hippocampus where they enhance the storage and consolidation of recent experiences
convolutions of brain
females > males (so overall surface area is the same)
vegetative state
alternates between periods of sleep and moderate arousal, although even during the more aroused state the person shows no awareness of surroundings and no purposeful behavior • breathing is more regular • painful stimulus produces at least autonomic responses • minimally conscious state
Delayed Nonmatching-to-sample task
an animal sees an object (the sample) and then, after a delay, gets a choice between two objects, from which it must choose the object that is different from the sample
Delayed Matching-to-sample task
an animal sees an object (the sample) and then, after a delay, gets a choice between two objects, from which it must choose the one that matches the sample
Pineal Gland
an endocrine gland located just posterior to the thalamus that releases the hormone melatonin
punishment
an event that suppresses the frequency of the response
sleep spindles during stage 2 sleep indicate
an exchange of information between the thalamus and cerebral cortex • sleep spindles increase in number after new learning
coma
an extended period of unconsciousness caused by head trauma, stroke, or disease • low levels of brain activity and little or no response to a stimuli • followed either by death or recovery within a few weeks
St. John's Wort
an herb used as an antidepressant - Not regulated by the FDA so people can get without a prescription meaning they often take incorrect doses - Increases effectiveness of liver enzyme that breaks down toxins which can decrease the efficacy of other drugs one may be taking by breaking down the medication
Cravings
an insistent search for an activity - even after long abstinence, exposure to cues associated with substances triggers a renewed craving - strong "want" but not always strong "like" - repeated exposure to addictive substances alters receptors in the nucleus accumbens and other reward areas so they become more responsive to addictive substances/cues and less responsive to other types of reinforcement - repeated exposure also disrupts activity in the prefrontal cortex and other areas responsible for restraining impulses
male gonads produce
androgens (facial, axillary, pyramid pubic hair; lower voice; altered hairline; muscle and genital development)
male adrenal glands
androgens (see above) grow pubic hair in a pyramid
female adrenal glands produce
androstenedione (axillary and pubic hair) grow pubic hair in upside down triange
damage to lateral hypothalamus
animals refuse food and water, avert head as if food were distasteful but if kept alive ability to eat returns
progesterone
another predominantly female hormone that prepares the uterus for the implantation of a fertilized ovum and promotes the maintenance of pregnancy
Ketamine
antagonizes NMDA type glutamate receptors and increase formation of new synapses produces rapid antidepressant effects in patients who don't respond to other medications • Also produces hallucinations and delusions
supplement these drugs with
antidepressants and/or antipsychotics • antidepressants are risky though because they can sometimes cause mania • antipsychotics have unpleasant side effects
MAOIs (Monoamine Oxidase Inhibitors)
antidepressants that block the enzyme monoamine oxidase (MAO), a presynaptic enzyme that metabolizes catecholamines and serotonin into inactive forms - Earliest form of antidepressant - No longer first choice for treatment • Cheese effect → Must avoid tyramine (in cheese, raisons, and more) because tyramine + MAOIs increases blood pressure
SNRIs (Serotonin Norepinephrine Reuptake Inhibitors)
antidepressants that block the reuptake of both serotonin and norepinephrine
SSRIs (Selective Serotonin Reuptake Inhibitors)
antidepressants that block the reuptake of serotonin - Produce milder side effects than tricycles with about the same effects -- mild nausea, headache, sometimes nervousness, sometimes sexual ---because indirectly affects DA release and decreases sex drive/causes sexual dysfunction
tricyclics
antidepressants that operate by blocking the transporter proteins that reabsorb serotonin, dopamine, and norepinephrine into the presynaptic neuron after their release, thus prolonging the presence of the neurotransmitters in the synaptic cleft - also block histamines (drowsiness), acetylcholine (dry mouth, difficulty urinating), and certain sodium channels (heart irregularities, etc) leading to side effects - can overdose on
opiate withdrawal
anxiety, sweating, vomiting, diarrhea
reinforcer
any event that increases the future probability of a response
Implicit memory
anything that comes underneath the surface of your consciousness; things that aren't thought about consciously but are just done • Priming • Procedural • Associative • Non-associative → habituation & sensitization
Aplysia as an Experimental Animal
aplysia → a marine invertebrate related to the slug, popular for studies of learning • has fewer, large neurons, easy to study
differences in hunger or digestion genes
are another possible cause as well as activity level genes
London Taxi drivers hippocampi
are highly activated when answering spatial questions about routes - They also have larger posterior hippocampi suggesting adult hippocampi growth with increased spatial memory
testosterone and estradiol are
are very chemically similar and testosterone can be aromatized into estradiol in rodents • drugs that block this block the organizing effects of testosterone on sexual development and impair male sexual behavior and fertility • Alpha-fetoprotein
Sexually dimorphic nucleus
area in the anterior hypothalamus that is larger in males than in females and contributes to control of male sexual behavior
recent memories include more
detail/context & relies more on hippocampus - at first, rat responds best when in same location as training • later, rat can perform as well, regardless of location - humans: recalling recent memory (which usually has more details) activates the hippocampus • recalling older memories which require contextual details (e.g. episodic memories) can also activate the hippocampus • other memories may not activate the hippocampus
Free-running circadian rhythm
determined by people living in caves - constant bright light? → avg. 23 hours - constant dark? → avg. 25 hours - suggests an internal clock
spatial view cells
different cells respond based on where you are looking in space
previously thought only hormones affected sex, but now know some differences are
directly controlled by genes • at least 3 genes on the Y chromosome are specific to men • one gene specific to women on X
REM Behavior disorder
disorder where major postural muscles do not relax during Rem sleep causing people to move vigorously during their REM periods, apparently acting out their dreams - may be due to inadequate inhibitory transmission; problem in pons • acting out your dreams • neurodegenerative disorder • associated with pons damage - treatment • benzodiazepines (e.g., clonazepam) → inhibits movements
men are more likely to describe directions in terms of
distance whereas women are more likely to use landmarks • gay men are also more likely to use landmarks
PGO waves
distinctive high-amplitude electrical potentials
mice with obese gene
do no make leptin so their brain reacts as if its body has no fat stores and must be starving so the mouse eats as much as possible, conserves its energy by not moving much, and fails to enter puberty • injections of leptin reverse these symptoms
Rose study
do task, smell rose- some students, pump rose smell in at night, triggered memory of doing task, students did better on same task the next day • IRL- you adapt to smells really quickly, studying next to smells doesn't work bc brain adapts doesn't register
fevers above 103 F
does more harm than good and fevers above 109 F are life-threatening
Genetics and schizophrenia
does not depend on any single gene
drugs that block protein synthesis in hippocampus (before learning or right after)
doesn't prevent learning but prevents remembering task 2 days later
female infants look at
dolls more than trucks whereas boys look at them equally • male moneys played more with balls and female moneys played more with dolls
almost all abused drugs increase activity at
dopamine and norepinephrine synapses
mesolimbocortical system
dopamine pathway projecting from the midbrain Tegmentum to the limbic system and prefrontal cortex - drugs that block dopamine synapses act on these neurons • also block dopamine in the mesotriatal system
mesotriatal system
dopamine pathway projecting to the basal ganglia • produces tardive dyskinesia
drugs all block
dopamine synapses
hypnagogic & hypnopompic hallucinations
dreamlike experiences that a person has trouble distinguishing from reality, often occurring at the onset of sleep
Methadone
drug that activates the same brain receptors as opiates and produces the same effects but is less harmful and can be used to treat opiate addiction • taken orally so it gradually enters the blood and then the brain avoiding the "rush" effect • withdrawal symptoms are gradual as well because it leaves the brain slowly
antipsychotics/neuroleptics
drugs that tend to relieve schizophrenic and similar conditions - two chemical families -- phenothiazine group → includes chlorpromazine -- butyrophenone group → haloperidol - e.g. clozapine, amisulpride, risperidone, olanzapine, aripirazole - positive AND negative symptoms -- partial DA agonist -- more strongly antagonize 5-HT2 receptors -- ↑ glutamate release - side effects: weight gain, ↑ risk of diabetes, impaired immune system
easier to adjust to jet lag going...
east to west because we phase delay our circadian rhythms • biological clock is faster than environmental clock which is easier for us to adjust to
Factors which ↑ or ↓ eating - insulin, appetizer effects
eating just a little bit stimulates hunger because it raises insulin levels causing sugars to be pulled out of blood increasing hunger
Testicular Feminization/Androgen Insensitivity -- Brain?
feminized
self-stimulation of the brain
electrodes inserted into the septum and certain other places of rats brain and they pressed as often as 2,000 time per hours to stimulate - all these areas directly or indirectly increase the release of dopamine or norepinephrine in → the nucleus accumbens • central to reinforcing experiences of all types
what type of memories form quickly
emotionally significant memories form quickly whereas unimportant, boring memories are harder to form
Can you explain how this is consistent with the experience of REM sleep: Increased pons and limbic
emotions during dreams
Weakening synapses helps to
emphasize stronger synapses
The Clinico-Anatomical Hypothesis
emphasizes that dreams begin with arousing stimuli that are generated within the brain combined with recent memories and any information the brain is receiving from the sense but puts less emphasis on the pons, PGO waves, or Rem sleep, instead regarding dreams as thinking that takes place under unusual conditions - either internal or external stimulation activates parts of the parietal, occipital, and temporal cortex which develops into a hallucinatory perceptions with no sensory input from area V1 to override it - general pattern of brain activity during REM and SWS - brain making interpretations and trying to come up with what may mean- making sense of dreams - esp. ↑ visual association activation
in humans, testosterone
enters neurons where it exerts masculinizing effects directly
Severe Impairments of Episodic Memory
episodic memory - memories of single personal events - relationship between losing episodic memory and difficulty imagining the future • b/c this requires using past events as a basis • same brain areas (e.g. hippocampus) are activated - couldn't describe events since his surgery - very few personal experiences before this - K.C. (also had amnesia): no (old or new) episodic memories
damage to SCN
erratic body/sleep & wake rhythms
studies suggest that prenatal hormones
especially testosterone alter the brain in ways that influence differences between boys and girls in their activities and interests • combines with situational factors of parents giving kids toys they like repeatedly and parents giving kids gendered toys from the start
most prominent estrogen
estradiol
female gonads produce
estradiol (breast, fat distribution, maturation of female genitalia)
if pregnancy occurs
estradiol and progesterone levels continue to increase
Parental behavior (in rats) - Females
estradiol, prolactin, oxytocin
ovaries produce
estrogens
Episodic memory
event; body of knowledge tied to contextual information, mostly time
Sham-feeding experiments
everything an animal swallows leaks out of a tube connected to the esophagus or stomach which makes the animal eat and swallow almost continually without becoming satiated which means taste contributes to satiety but is not sufficient
aromatized testosterone in humans
evidence that aromatized testosterone may lead to masculinization in humans • DES → thought to stall premature labor but actually a type of synthetic estrogen that didn't change anything in male babies exposed to it, but did masculinize female babies exposed
hunger-sensitive cells receive
excitatory input from the taste pathway and from axons releasing the neurotransmitter ghrelin
not enough to drink/water tastes bad
excrete more concentrated urine and decrease sweat - Posterior pituitary releases vasopressin (aka antidiuretic hormone [ADH]) to raise blood pressure by constricting blood vessels • Increased blood pressure helps compensate for decreased blood volume • Also enables the kidneys to reabsorb water from urine to make urine more concentrated
Night Terrors
experiences of intense anxiety from which a person awakens screaming in terror • more severe than a nightmare • occur during NREM sleep and are more common in children than in adults • usually amnesia for the event
disorganized thought
expressed in disorganized speech → rambling or incoherent - loose associations - word salad
D1 and D5 receptors stimulated by moderate concentrations
facilitate erection of penis and sexually receptive postures in female
mixed agonist-antagonist
facilitates some neurotransmitters and inhibits other OR agonizes at some doses, antagonizes at others
hallucinations
false sensory experiences
amygdala
fear memories
low levels of testosterone (converted to dihydrotestosterone within cells)
female genitals - estradiol
density of neurons in temporal lobe
females > males
hippocampus
females > males
male mice injected with estrogens
have little effect on - UNLESS he lacks typical androgens/receptors resulting from • castration (removal of testes) • a genetic deficiency of androgen receptors • prenatal exposure to drugs that interfere with androgen response - estradiol does produce abnormalities of the prostate gland
thin parents often
have thin children and vice versa • evidence for genetic and/or prenatal environment influence
weight loss drugs
have unpleasant side effects in general • lorcaserin → new drug that stimulates one type of serotonin receptor and has relatively few side effects but that is only modestly helpful is promoting weight loss
almost everyone wants a mate who is
healthy, intelligent, honest, and attractive
many fish, especially salmon, contain oils that are
helpful for brain functioning and several studies have found that eating more fish helps some people improve their memory and reasoning abilities
diabetes II
high levels of insulin, but cells not longer accept insulin
dopamine hypothesis of schizophrenia
holds that schizophrenia results from excess activity at dopamine synapses in certain brain areas, especially the basal ganglia - extensive abuse of amphetamines or stimulants induces substance-induced psychotic disorder → hallucinations and elusions
ghrelin
hormone triggers stomach contractions when released by the stomach during periods of food deprivation and acts on hypothalamus to increase appetite • people with more ghrelin are 2x as likely to become obese
Androgens
hormones more abundant in males - e.g., testosterone → most common in human males - dihydrotestosterone - androstenedione
estrogens
hormones that are more abundant in females • e.g., estradiol → most common in human females • estrone • estriol
Factors which ↑ or ↓ eating - Taste input
how good something tastes
during sleep neurons in the thalamus become
hyperpolarized, decreasing their readiness to respond to stimuli and decreasing the information they transmit to the cortex • when they do fire, they fire in synchronous bursts, yielding the high-amplitude waves that characterize slow-wave sleep
bipolar II
hypomanic episodes
poikilothermic animals risk dying in below freezing weather because
ice crystals may form in their blood vessels and cell membranes tearing them apart and killing the animal - this is avoided by... • burrowing and finding other sheltered locations • stocking antifreeze chemicals in the blood at the start of winter • actually freezing but having mechanism to reduce the damage
Specificity
if some of the synapses onto a cell have been highly active and others have not, only the active ones become strengthened
sleep apnea
impaired ability to breath while sleeping; sleep disruption, leading to excessive sleepiness or insomnia, that is due to a sleep-related breathing condition such as apnea - people with sleep apnea have breathless periods of a minute or so from which they awaken gasping for breath • may not notice awakenings but do notice consequences of sleepiness, impaired attention, depression, heart problems - multiple brain areas with lost neurons → deficiencies of learning, reasoning, attention, and impulse control • unsure whether brain abnormalities led to sleep apnea or if sleep apnea led to brain abnormalities o mice studies show the latter may be true - ↑ C02 → activation of chemoreceptors → breath - correlated with lost neurons, impaired learning, attention problems, sleepiness, depression, etc
large amounts of cortisol
impairs memory
damage to the prefrontal cortex
impairs performance pretty precisely - many elderly people have changes to the prefrontal cortex which can cause impairments to working memory
estradiol
important for internal organs and normal sexual behavior
Vasopressin
important for social behavior in many species, partly by facilitating olfactory recognition of other individuals
acetylcholine is...
important for wakefulness and REM sleep - acetylcholine → REM (& wakefulness; EEG desynchrony) • carbachol stimulates cholinergic activity → REM
prefrontal cortex
important in working memory - increased activity during delayed response test - aged monkeys: ↓ # of neurons & input to prefrontal area - older humans with memory impairment (↓ prefrontal activity) vs. older humans with intact memory (↑ prefrontal activity) - stimulants → ↑ prefrontal activity → better memory
(hot) AH/POA
inhibits NEi receptors to increase vasodilation & reduce metabolism. Also increases cholinergic activity to increase sweating.
brain areas surrounding the third ventricle are
in a good position to monitor the contents of the blood, because the BBB is weak in this area, enabling chemicals to enter that would not reach neurons elsewhere in the brain • weak BBB though may expose neurons to potential harm
homosexual behavior occurs
in many species
temperature affects behavior
in many ways that we easily overlook
ketoacidosis
inability to breakdown ketones • can be dangerous
Anterograde amnesia
inability to form memories for events that happened after brain damage
Insomnia
inadequate sleep; difficulty initiating or maintaining sleep, or non-restorative sleep, for at least 1 month - daytime sleepiness - usually a symptom • disease, worries, circadian rhythm issues, periodic limb movement, sleep apnea, use of sleep medication, etc. - not a "short sleeper" - 9% US (estimate varies)
Sleep spindles are corre. with IQ but can also
increase after learning • increased chances of "aha" moments • scientists that get ideas while they are sleeping • correlation b/w REM sleep and IQ • mentally retarded children = decreased REM • gifted children = increased REM • college students during exams = increased REM density
When activated, the lateral hypothalamus will
increase eating
during sleep, axons that release the inhibitory neurotransmitter GABA
increase their activity, interfering with the spread of information from one neuron to another - connections from one brain area to another become weaker - this means sleep can be local within the brain → may have substantial inhibition in one area but not in another • dolphins → can sleep on one side of their brains but not the others • sleepwalkers → asleep in much of the brain, but awake in the motor cortex and a few other areas
those with BN have several biochemical abnormalities
increased production of ghrelin, a hormone associated with increased appetite • probably result of binge/purge rather than cuase • after therapy that decreases symptoms, ghrelin and other hormone levels return to normal
stimulation of the lateral hypothalamus
increases drive to eat
Factors which ↑ or ↓ eating - ghrelin
increases eating - stomach secretes → stomach contractions & → hypothalamus → increased appetite & → hippocampus → enhanced learning - Prader-Willi syndrome
glycine
increases efficacy of NMDA receptors • works in cohort with antipsychotic drugs, especially in regards to negative symptoms
Instrumental/Operant Conditioning
individual's response leads to reinforcer or punishment; association between behavior & consequence
Testicular Feminization/Androgen Insensitivity
individuals with an XY chromosome pattern normal amounts of androgens but lack the receptor that enables androgens to activate genes in a cell's nucleus - Occurs in various degrees resulting in anatomy that ranges from a smaller than average penis to genitals like those of a typical female
Increasing tryptophan helps the brain produce melatonin which
induces sleepiness • tryptophan enters the brain by an active transport protein that it shares with phenylalanine and other large amino acids • when you eat carbs, your body reacts by increasing secretion of insulin which moves sugars into storage and also moves phenylalanine into storage • by reducing competition from phenylalanine, this process makes it easier for tryptophan to reach the brain, inducing sleepiness
treatments for alzheimers are often
ineffective likely because Alzheimer's is too progressed by the time it's discovered
sex hormone early in life influence
influence development in parts of the hypothalamus, amygdala and other brain areas
Note that the arcuate nucleus can increase or decrease eating directly by
influencing LH activity or indirectly by influencing PVN activity (or do both simultaneously).
Areas involved with "wake" and areas involved with "sleep" ...
inhibit each other. - So...you are either awake (though levels may vary) or asleep (though levels may vary). - Hypocretin/orexin prevents the "flip-flop" • If orexin is NOT present, then narcolepsy occurs and people "flip-flop" between sleep and awake
opiate drugs work to
inhibit neurons that release GABA a transmitter that inhibits the firing of dopamine neurons • inhibiting an inhibiter results in an increase of dopamine release
The arcuate nucleus, in turn, can
inhibit or activate the paraventricular nucleus (PVN). It activates the PVN by secreting α-melanocyte stimulating hormone ((αMSH).
evidence against safety from predators
lions sleep a lot and they're not worried about predators
the hormones associated with fertility move women's mate preferences toward men who
look and act more masculine
Factors which ↑ or ↓ eating - distension of duodenum
looking for fat to signal satiety • via CCK • closes sphincter muscle • stim. vagus nerve → hypothalamus → shorter CCK
people with sleep apnea are advised to
lose weight, avoid alcohol and tranquilizers
Retrograde amnesia
loss of memory for events that occurred before the brain damage - HM experienced both, suggesting the hippocampus is implicated in new and old memories
hormonal response to hypovolemia
low blood volume → kidneys release renin into blood → proteins in blood form angiotensin I → angiotensin I is converted to angiotensin II → angiotensin II constricts blood vessels and stimulates cells in subfornical organ to increase drinking
2/3 of total energy is spent
maintaining body temperature (basal metabolism) • requires more food which takes time to find
Double Depression Disorder
major depression plus dysthymia • Dysthymia is "normal" state of being • Experience major depressive episodes but never return to happy/normal baseline because dysthymia is normal
hormones will not
make adult males act like females and vice versa but hormones injected early in life have much stronger effects
hormones Facilitate or inhibit Sexual Behavior BUT do not CAUSE sexual behavior but
make conditions conducive to sexual behavior • instead, they do things like change sensitivity in penis, vagina, cervix, etc.
word salad
makes no sense
Factors which ↑ or ↓ eating - leptin
makes you feel full - secreted by fat cells
high levels of testosterone
male genitals
Testosterone is essential for
male sexual arousal • increases touch sensitivity to the penis • bind to receptors increasing response of parts of the hypothalamus → ventromedial nucleus, MPOA, anterior hypothalamus
amygdale
males > females
overall size of brain
males > females
white matter
males > females
damage to POA/AH
mammals can only regulate body temperature by behavioral mechanisms NOT physiological ones
tolerance
many drug effects decrease as addiction develops - Learned to a large extent → cues associated with receiving the drug activate learned mechanisms that counteract the effects of the drug • Can be weakened through extinction
diet drinks
many people drink diet drinks instead but do so in addition to their usual sugar intake or maybe even increased sugar intake
Our Changing View of Consolidation
many short term memories are not simply temporary stores on their way to being long-term memories
arcuate nucleus
master area for controlling appetite
sleep sex
masturbating or engaging in sex while asleep
most mammals at age of weaning lose the intestinal enzyme lactase necessary to metabolize lactose, the sugar in milk
may be an evolved mechanism to encourage weaning humans are a partial exception to this rule - some people can consume lactose but prevalence of the necessary gene varies • in China and surrounding countries, nearly all adults cannot metabolize lactose • gene is common in societies with long history of domesticated cattle
people without stomachs though still report satiety because
meals end after distension of the stomach OR the duodenum
electroencephalogram (EEG)
measure brain activity - the EEG enables brain researchers to monitor brain activity during sleep
electrooculogram (EOG)
measure eye movements
electromyogram (EMG)
measure muscle tension/movement
Symptoms of Alzheimer's Disease
memory problems - varies from time to time! • malfunctioning (not just dying neurons) - confusion, depression, restlessness, hallucinations, delusions, sleeplessness, loss of appetite - no diagnosis until they have died because you need to actually look at the brain • before death it is called suspected Alzheimer's - gradually progresses to • more severe memory loss, confusion, depression, restlessness, hallucinations, delusions, sleeplessness, loss of appetite
testosterone Correlates positively with
men's sexual arousal and their drive to seek sexual partners - impotence
Dysthymic Disorder
mild symptoms of depression for a longer period of time
Twin & adopted children
moderate heritability for depression • MZ twins have higher rates of concordance
Factors which ↑ or ↓ eating - distension of stomach
more likely to feel satiated when full • via vagus nerve
high levels of amyloid-β cause
more phosphate groups to attach to tau proteins - altered tau cannot bind to its usual targets so spreads to cell bodies and dendrites -- magnifies the damage, creates tangles --- tangles → structures formed from degeneration within neurons
Activating effects
more temporary effects, continuing only while a hormone is present or shortly beyond - degree of sex drive, many things in pregnancy - organizing effects set the stage for activating effects • i.e. set up female hypothalamus for menstrual cycle • not an absolute distinction between two effects
Generally, humans drink
more than we need and excrete the excess - Drinking without eating enough can be harmful because body salts begin to be excreted at harmful levels
OVLT & SFO (& stomach) near the third ventricle
most receptive to what is in the blood stream - Measure tension of cell membranes
Korsakoff's mostly occurs in
mostly in chronic alcoholics who go weeks at a time on a diet of nothing but alcoholic beverages lacking in vitamins - brain needs thiamine (vitamin B1) to metabolize glucose - prolonged deficiency leads to loss or shrinkage of neurons in the brain • mostly the dorsomedial thalamus → main source of input to the prefrontal cortex
humans have three version of PER protein and several proteins closing related to TIM
mutations to these genes cause alterations of sleep schedules
Cooperativity
nearly simultaneous stimulation by two or more axons produces LTP much more strongly than does repeated stimulation by just one axon
prolactin
necessary for milk production and for certain aspects of maternal behavior
Inhibiting an inhibitor produces
net excitation and that is how the stimuli for hunger increase eating and arousal
↓ estradiol & progesterone levels in those with history of postpartum depression
new depressive symptoms - estradiol supplements in middle-aged women with depression = ↓ depressive symptoms - BUT this decrease always occurs so sex hormones cannot be the whole story (stress-diathesis model)
Can you explain how this is consistent with the experience of REM sleep: Decreased motor cortex
no actual movement
BUT ½ of all late-onset Alzheimer's have
no known relatives with the disease - Most cases are sporadic NOT genetic
avolition
no motivation
Can you explain how this is consistent with the experience of REM sleep: •Decreased primary visual cortex
no real sight
causes of insomnia
noise, uncomfortable temperatures, stress, pain, diet, neurological or psychological disorders, and medications - can be due to shifts in circadian rhythms • phase delayed → hypothalamus thinks it isn't late enough (has trouble falling asleep at the usual time) • phase advanced → falls asleep easily but awakens early
weight loss drugs
not very many long term studies on them - fen-phen** • fenfluramine (↑ 5-HT) • phetermine (↑NE, ↑ DA) - caused cardiovascular problems in significant minority so pulled off the market - sibutramine (Meridia) (↑5-HT, ↑ NE) - orlistat (Xenical, Alli) (blocks up to 30% of fat) • 5% loss of body fat
follicle...
nurtures the ovum (egg cell) and produces several types of estrogen, including estradiol
Syndromal obesity
obesity that results from a medical condition
examples of breakdowns of homeostatic processes
obesity, anorexia, high blood pressure, diabetes
Obstructive Sleep Apnea
obstruction in breathing passageway - Nasal valve collapses - Congestion while sick - Overweight pushes trachea closed during sleep - Deviated septum - Enlarged tonsils/adenoids
secondary sexual characteristics
occur before primary sexual characteristics - females show them before males do
grossly disorganized behavior
odd behavior or catatonic behavior
exogenous melatonin: single morning dose?
often not effective because there are such strong cues to stay awake
male sex hormones
one X, one Y chromosome
mammals need two mechanisms for material behavior
one hormone-dependent and one not • because early on, hormones compensate for the mother's lack of familiarity with the young and later experience maintains the maternal behavior even though the hormones start to decline
Long term potentiation (LTP)
one or more axons connected to a dendrite bombard it with a rapid series of stimuli which leaves of the synapses potentiated (more responsive to new input of the same type) for minutes, days, or weeks • persistent strengthening of a synapse • protein-synthesis
arcuate nucleus has
one set of neurons sensitive to hunger signals and a second set sensitive to satiety signals • damage to one set or the other can lead to starvation or excessive eating
minimally conscious state
one step higher than vegetative state with occasional, brief periods of purposeful actions and a limited amount of speech comprehension - both this and vegetative state can last for months or years
additional pathway from the PVN to cells in the lateral hypothalamus release
orexin
Lateral (& posterior) hypothalamic nuclei
orexin (hypocretin) pathway → axons from the lateral and posterior nuclei of the hypothalamus extend to the basal forebrain and many other areas, enhancing wakefulness by releasing orexin • two names for two research teams that discovered neuropeptide simultaneously • orexin is necessary for staying awake NOT waking up • drugs that block orexin may help people go to sleep with possibly fewer side effects • lacking in those with narcolepsy
when you lose a significant amount of body fluid
osmotic pressure stays the same but you still need to replace fluid
Congenital Adrenal Hyperplasia (CAH)
overdevelopment of the adrenal glands from birth that causes an excess release of ACTH, thus more of the adrenal glands other hormones • Causes no changes in males • Causes females to have various degrees of masculinization of their external genitals • Treatment → medical treatments to regain normal hormone levels and sometimes surgery • abnormally low cortisol → ↑ adrenal gland secretion (including androgens) • boys = okay
damage to the VMH
overeating and weight gain
Associativity
pairing a weak input with a strong input enhances later response to the weak input, meaning LTP matches what we would expect of Hebbian synapses • In some cases a synapse was almost completely inactive before LTP becomes effective afterward
Classical Conditioning
pairing two stimuli changes the response to one of them; association between conditioned stimulus and unconditioned stimulus (and thus to the unconditioned response) • pioneered by Ivan Pavlov • experimenter presents conditioned stimulus (CS) which elicits no response then presents the unconditioned stimulus (UCS) which automatically elicits the unconditioned response (UCR) • after pairing the CS and the UCS, the CS begins to elicit the same response (UCR) but now called the CR
toxoplasma gondii
parasite that reproduces only in cats but can infect humans and impairs brain development in infants or children - those with schizophrenia have more antibodies for this than normal people
The Suprachiasmatic Nucleus (SCN)
part of the hypothalamus located just above the optic chiasm and the main driver of rhythms for sleep and body temperature - generates circadian rhythms in a genetically controlled manner • isolated SCN neurons → have very regular activity • 20-hour SCN in hamsters → transplanting 20-hr SCN from abnormal hamster to normal hamster causes normal hamster to adopt 20-hr cycle
Pontomesencephalon
part of the reticular formation that contributes to cortical arousal • Maintains arousal during wakefulness and increases it in response to new or challenging tasks by releasing acetylcholine and glutamate into the forebrain, exciting the thalamus, hypothalamus, and basal forebrain • Stimulation of this area awakens a sleeping individual or increases alertness
gastric bypass surgery
part of the stomach is removed or sewed off so that food cannot enter • stomach distension is an indicator of satiety so having a smaller stomach means feeling satiated faster • usually though people just go from being morbidly obese to just obese • 10-20% of people experience serious side effects
gene FTO
people weigh 6-7 lbs mores than others and have a 2/3 greater probability of becoming obese
Hermaphrodites
people with anatomies intermediate between male and female or a mixture of male and female
visuospatial sketchpad
permits people to temporarily hold and manipulate visual images - hold vision
To cool ourselves when the air is warmer than body temperature, humans have only one physiological mechanism
perspiration (sweat) • for species that don't sweat the alternatives are → panting and licking themselves • have to drink enough water to sweat; without enough water you stop sweating to prevent dehydration and risk overheating
confabulation
phenomenon in which patients fill in memory gaps with guesses • usually, answer was true in the past (though not now) • study strategy → repeatedly read information whereas those without Korsakoff's should test themselves • people pull up many ideas and don't know what's right so they just pick one and stick with it going forward • mainly occurs with episodic memory • things they did in the past but not in the present • usually more pleasant than reality
engram
physical representation of what has been learned
shift work
pilots, medical interns, shift workers in factories find that → their duration of sleep depends on when they go to sleep - try to sleep in the morning → sleep only briefly even if been awake for hours • people sleep best when they work in very bright light at night and then sleep in very dark rooms in the day
most commonly abused drugs come from
plants • plant chemicals that are produced to affect other species may also affect humans because other species share the same neurotransmitters/hormones with humans
Mullerian ducts
precursors to the female internal structure
Wolffian ducts
precursors to the male internal structure
The Neurodevelopmental Hypothesis
prenatal and neonatal influences (genetic, environmental, or both) produce abnormalities that leave the developing brain vulnerable to other disturbances later in life, including but not limited to highly stressful experiences resulting in mild brain abnormalities and major disorders of behavior • e.g. poor nutrition, premature birth, low birth weight, complications during delivery (excessive bleeding, loss of oxygen, complications due to Rh compatibility between mother & child), childhood head injury (all correlation data!)
homosexual women are more affected by
prepulse inhibition then heterosexual women
fake food
preservatives - e.g., soda (high fructose corn syrup) - diet soda → metabolic pathways are messed up when you take in something sweet but no sugar - trans fat → everyone agrees its bad for you • "no" trans fat doesn't mean none
POA/AH
primary area for controlling physiological mechanisms of temperature regulation • monitors itself
the SRY gene causes
primitive gonads to develop into testes which produce androgens that increase the growth of the testes creating positive feedback for more androgens and more growth
type II/B alcoholism
rapid onset alcoholism usually before age 25 • mostly in men with family history of alcoholism
Morris Water maze
rats swim through murky water to find a rest platform just under the surface - If the rat has hippocampal damage, it cannot swim to the platform from new places
AMPA receptor
receptor excited by the neurotransmitter glutamate but that can also respond to a drug called AMPA - Typical ionotropic receptor → when AMPA receptors are stimulated, they open a sodium channel to let ions enter the postsynaptic cell
adult hormone levels do NOT explain sexual orientation BUT
sexual orientation may depend on testosterone levels during a sensitive period of brain development - (e.g., pigs, zebra finches, rats) testosterone levels = homosexual behavior - (female animals) testosterone = mounting of partners
gene coding for the dopamine type 4 receptor
short or long type • long form → less sensitive; stronger than average cravings for additional alcohol after one drink
women tend to be better than men at
recognizing facial expressions of emotion • after receiving testosterone most women became less accurate at recognizing faces
Working Memory
refers to the way we store information while we are working with it
other pathways in the lateral hypothalamus
regulate cells in the basal forebrain - basal forebrain cells provide axons that extend throughout the thalamus and cerebral cortex, some of which release acetylcholine which is excitatory and increases arousal • acetylcholine and sleep → released during wakefulness and REM sleep but NOT during slow-wave sleep
testosterone primes MPOA and other areas to
release dopamine making male more likely to copulate
the remnant of the follicle (corpus luteum)
releases the hormone progesterone which prepares the uterus for the implantation of a fertilized ovum
Phonological loop
represents all of STM in earlier models (words, numbers, etc.) - i.e. rehearsal (like short-term memory) - hold sound
norepinephrine
responsible for increasing arousal but also abolishes REM sleep - interferes with REM
restoration of mind
resting the mind, consolidating memory, intelligence, creativity, brain development
Anterior Cingulate Cortex
reward system (e.g. some cells respond when reward is greater than expected; others respond when reward is less than expected
Sleepwalking
runs in families, occurs mostly in children • often accompanies other sleep disorders • more common when people are sleep-deprived or under stress • most common during slow-wave sleep early in the night and is not usually accompanied by dreaming • NREM (3 & 4)
lithium
salt used to treat bipolar disorder; stabilizes mood preventing a relapse into either mania or depression • dosage must be carefully regulated
↓ glutamate release (esp. prefrontal & hippocampus) =
same symptoms as ↑ DA • DA inhibits glutamate release and vice versa • antipsychotic drug effects are consistent with this theory as well
sleep's original function may have been to
save energy during inefficient times of the day when activity would be wasteful and possibly dangerous
Endogenous Circannual Rhythm
self-generated rhythm that lasts about a year • Ex → migratory birds
Endogenous circadian rhythm
self-generated rhythm that lasts abut a day • Ex. → sleep-wake cycle, eating, drinking, urination, hormone secretion, metabolism, sensitivity to drugs, mood, etc. o Urge to sleep depends partly on the time of day, not just how long you slept o individual sleep-wake cycles lengths vary • blood pressure • sleepiness • body temperature
REM sleep depends on a relationship between the neurotransmitters
serotonin and acetylcholine
CaMKII
sets in motion a series of reactions leading to release of CREB • CREB goes to the nucleus of the cell and regulates the expression of several genes
receptors in the OVLT, SFO, stomach, and elsewhere send info to
several parts of the hypothalamus including the supraoptic nucleus and the paraventricular nucleus (PVN) which control the rate at which the posterior pituitary releases vasopressin
SRY gene
sex-determining region on the Y hormone
5-HT interferes with
sexual activity, in part, by blocking DA
women with CAH have difficult
sexual adjustment especially with surgery • most report no orgasm and few relationships
Paradoxical/REM sleep
sleep that is deep in some ways and light in others and is characterized by rapid eye movements • During paradoxical/REM sleep the EEG shows → irregular, low-voltage fast waves that indicate increased neuronal activity but also relaxed postural muscles, erections, vaginal moistening, and variable heart rate, blood pressure, and breathing rate • REM and dreams are not the same thing but 80-90% of people awakened reported dreams when awoken during REM sleep
Stages 3 (delta waves <50%) and 4 (delta waves >50%)
slow wave sleep
Testicular Feminization/Androgen Insensitivity -- Genitals?
smaller penis to female genitalia
When an axon releases glutamate repeatedly
so many sodium ions enter through the AMPA channels that the dendrite becomes strongly depolarized which displaced the magnesium molecules, enabling the glutamate to open the NMDA channel - At this point, both sodium and calcium enter through the NMDA channel
Ineffective Zeitgeber
social stimuli (i.e. the effects of other people) unless they induce exercise or other vigorous physical activity
much of child play results from
socialization meaning what toys children get from parents to play wit
if you eat something salty
sodium ions spread through the blood and the extracellular fluid but do not cross the membranes into cells resulting in a higher concentration of solutes outside the cell than inside so the resulting osmotic pressure draws water from the cells into their extracellular fluid - salt goes into digestive tract, small intestine; salts diffuse through villi into blood vessels/interstitial fluid and you end up losing water
what do some believe is the central problem of schizophrenia?
some believe impairments of attention and working memory are the central problem
intersexes
some people develop an intermediate appearance because of an atypical hormone pattern - Congenital Adrenal Hyperplasia (CAH)
more females than males experience
some physical attractions to both males and females • women switch more than men
true hermaphrodite
some testicular tissue and some ovarian tissue - occurs when a woman releases two ova impregnated by different sperm that then unite giving the fertilized ova XX and XY cells • rare
amino acids
some used to build, but most stored as triglycerides
a modified theory is that
someone with an addiction learns to use a substance to cope with stress
People with pineal gland tumors...
sometimes stay awake for days at a time
consistent, adequate sleep helps
stabilize mood and decrease the risk of a new episode
slow wave sleep
stages 3 and 4 of sleep which are occupied by slow, large-amplitude brain waves - Indicate highly synchronized neuronal activity
through most of human history
starvation has been a bigger problem that obesity
phase delay
stay awake later at night and then awaken late the next morning, already partly adjusted to the new time zone
keeping a high body temperature allows birds and mammals to
stay constantly ready for vigorous activity because muscles need to be warm to function
many blind people with damage to rods and cones
still have enough input the melanopsin-containing ganglion cells to entrain their sleep-wake cycle to the local pattern of sunlight
Zeitgeber
stimulus that resets the circadian rhythm - Light in land animals, tides for some marine animals
fat
stored as triglycerides • food is so readily converted into triglycerides because our ancestors needed energy stores because of food insecurity
adjusting to jet lag is....
stressful causing elevated levels of cortisol which damages neurons in the hippocampus (memory) • stress occurs when you experience jet lag → ↑ cortisol → ↓ hippocampal function/volume → ↑ memory IMPAIRMENTS
withdrawal
strong psychological an bodily reaction when a drug is absent and the body has come to expect it
Thompson et al
studied classical conditioning of eyelid response in rabbits • Paired a tone (CS) with a puff of air (UCS) • Rabbit began blinking (UCR/CR) at the tone (CS)
People with Hippocampal Damage: HM
suffered severe epilepsy and agreed to have a lobotomy to relieve symptoms in 1953 - hippocampus and some nearby structures of the medial temporal cortex (amygdala, rhinal cortex) removed from both hemispheres of HM's brain • hippocampus → active during the formation of memories and later recall - HM's seizures were reduced to 2/year, but his memory was severely impaired
Other oddities of schizophrenia
suggests prenatal problems - rates: type 1 diabetes < non-diabetic < type 2 diabetes - those with schizophrenia: -- ↑ risk of colon cancer but ↓ risk of respiratory or brain cancers -- rarely develop rheumatoid arthritis or allergies -- unique body odor (trans-3-methyl-2-hexenoic acid) but cannot smell it themselves - pregnant females with schizophrenic episode before birth: daughters; pregnant females with schizophrenic episode after birth: sons
puberty
surge in hormones causes physical changes, even to brain - changes stay even once hormones decrease
We don't inherit the disorder itself, but rather
susceptibility • Depression = ↑ rates of anxiety disorder, ADHD, alcohol or marijuana abuse, OCD, BN, migraine headaches, irritable bowel syndrome, etc. among relatives
Antidepressants seem to increase BDNF (brain-derived neurotrophic factor) which is important for
synaptic plasticity, learning, and proliferation of new neurons in the hippocampus - Those with depression have low levels of BDNF, so antidepressants raising them could relate to their effectiveness
why do we need Satiety mechanisms
takes ~15 minutes for water to be absorbed by body so need a faster mechanism to know when we've had enough water so we don't cause
tardive dyskinesia
temors and other involuntary movements that develop gradually and to varying degrees among patients • can last a long time • can be prevented with second-generation antipsychotics
Homeostasis
temperature regulation and other biological processes that keep body variables within a fixed range • homeostatic processes in animals trigger physiological and behavioral activities that keep certain variables within a set range • Set point • Negative feedback • not completely satisfactory because the body does not maintain complete constancy
current levels of testosterone and estradiol exert activating effects
temporarily modifying behavior
Suppressing the red nucleus
temporarily prevented the response but did not prevent learning
most widely known androgen
testosterone
testosterone level in single vs married men
testosterone level → single men > married men - testosterone level corre. with seeking partners - implication? - Testosterone levels do not seem to be changing - Males with more testosterone will remain single, men with less testosterone will be more likely to get married
Without MIH
the Mullerian duct develops and matures into the oviducts, uterus, and upper vagina
Allostasis
the adaptive way in which the body anticipates need depending on the situation, avoiding errors rather than correcting them; changes the set point (weight different now than in middle school) • much of this control depends on cells in the hypothalamus • toddlers prep for growth spurts by eating more
frequency of sexual activity in women correlates highly with
the amount of testosterone that women produce at the periovolutory period, the days around the middle of the menstrual cycle, when fertility is highest
after the end of a menstrual period
the anterior pituitary releases FSH → promotes the growth of a follicle in the ovary
Sex differences
the biological differences between males and females
If insulin levels stay high
the body continues moving blood glucose into the cells, including the liver cells, long after a meal and blood glucose levels drop causing hunger • Hibernating animals and even humans have this happen in autumn preparing for winter months
to limit drinking to not much more than you need at a given time
the body monitors swallowing and detects the distension of the stomach and upper part of the small intestine
older, less detailed memories depend mainly on
the cerebral cortex with less contribution from the hippocampus
hunger depends on
the contents of your stomach and intestines, the availability of glucose to the cells, and your body's fat supplies as well as your health and body temperature • but also social factors • key brain areas include several nuclei of the hypothalamus → arcuate nucleus
the hippocampus may be
the coordinator that brings together the different aspects of contextual memory
mass action
the cortex works as a whole, and more cortex is better
gender differences
the differences that result from people's thinking about themselves as male or female
basal metabolism
the energy used to maintain a constant body temperature while at rest - Maintaining body temperature requires about 2x as much energy as do all other activities combined - Produce that much heat largely by metabolism in brown adipose cells • Brown adipose cells → cells that are more likely muscle cells than like white fat cells - 2/3 fuel = basal metabolism
toward the middle of the menstrual cycle
the follicle builds up more and more receptors to FSH so the effects of diminishing FSH increase
the species with the most total sleep hours also have
the highest percentage of REM sleep • the amount of NREM varies less among individuals and among species
POA/AH and a couple other hypothalamic areas send output to
the hindbrain's raphe nucleus, which controls the physiological mechanisms
LTP occurs more readily in
the hippocampus
if not pregnant
the hormones decline, the lining of the uterus is cast off (menstruation), and the cycle begins again
the physiological changes that regulate body temperature depend on areas in and near
the hypothalamus, especially the anterior hypothalamus and the preoptic area → often treated as one area POA/AH
When glutamate attaches to an NMDA receptor at resting potential
the ion channel is usually blocked by magnesium ions - Membrane must depolarize for magnesium ions to leave to permit ions to flow
when blood volume drops
the kidneys release the enzyme renin which splits a portion off angiotensinogen, a large protein in the blood, to form angiotensin I, which other enzymes convert to angiotensin II
many axons containing dopamine pass through
the lateral hypothalamus so damage to the lateral hypothalamus disrupts these fibers
PVN inhibits
the lateral hypothalamus, an area important for eating
Thompson identified what as essential for learning
the lateral interpositus nucleus (LIP)
receptors also relay information to
the lateral preoptic area and surrounding parts of the hypothalamus, which control drinking
the more fat cells
the more leptin • leptin signals your brain about your fat reserves, providing a long-term indicator of whether you have been overeating or undereating • each meal also releases leptin so the amount of circulating leptin indicates something about short-term nutrition as well
much of the output of the arcuate nucleus goes to
the paraventricular nucleus (PVN) of the hypothalamus
duodenum
the part of the small intestine adjoining the stomach • the first digestive site that absorbs a significant amount of nutrients • fat in the duodenum releases a hormone called oleoyle-thanolamide (OEA) which stimulates the vagus nerve, sending a message to the hypothalamus to delay the next meal • any kind of food in the duodenum releases the hormone cholecystokinin
the glutamate hypothesis of schizophrenia
the problem in schizophrenics relates in part to deficient activity at glutamate synapses in the prefrontal cortex • increased dopamine produces the same effect as decreased glutamate
consolidation
the process of information being converted from short term memory to long term memory likely by building new synapses or other structural changes; strengthening of a memory
the concentration of chemicals in water determines
the rate of all chemical reactions in the body so water must be regulated within narrow limits
brain detects osmotic pressure with information from
the receptors around the third ventricle, including the OVLT (organum vasulosum laminae terminalis) and the subfornical organ (SFO) • receptors detect osmotic pressure and the sodium content of the blood
signals of both short and long term satiety provide input to
the satiety sensitive cells of the arcuate nucleus
efficacy
the tendency of a drug to activate the receptor
Homeothermic
using physiological methods to regulate body temperature despite changes in environmental temperature (aka endothermic) - mammals and birds • certain species may become poikilothermic during hibernation - costly, especially for small animals because animals generate heat in proportion to total mass but radiate heat in proportion to its surface area • small animals have higher surface-to-volume ratios so they radiate heat rapidly
Season of birth effect
the tendency of people born in winter have a slightly greater probability of developing schizophrenia than people born at other times of the year - Pronounced farther from the equator - Maybe due to viral infections → influenza during pregnancy causes for increased risk of schizophrenia • Cytokines pass placenta and can impair brain development • Fever slows the division of fetal neurons - born in winter (5-8% risk of schizophrenia) - infections: influenza, rubella, herpes, etc. - infection → immune response of mother (during 2nd trimester) → damaged brain - toxoplasma gondii infections in children • Those with schizophrenia: • ↑ rates of having a cat in childhood • ↑ rates of having antibodies for Toxoplasma parasite - several drugs relieve symptoms as well as block toxoplasma parasitic replication
Osmotic pressure
the tendency of water to flow across a semipermeable membrane from the area of low solute concentration to the area of higher concentration • rats with strong osmotic pressure have decreased anxiety
the stomach conveys satiety messages via
the vagus nerve and the splanchnic nerves • Splanchnic nerve
gastric bypass surgery
theory to make stomach smaller then bypass the small intestine but weight loss may be due to.. - decrease in ghrelin after surgery - side effects: infections, bowel obstructions, leakage of food, nutritional deficiencies
Osmotic Thirst
thirst caused by eating salty foods; a drive for water that helps restore the normal state of water and solute concentrations
Hypovolemic thirst
thirst caused by losing fluid by bleeding or sweating
Leptin: low levels vs. insensitivity
those with obesity either - do not produce significant amounts of leptin (reason they are obese) • giving leptin can decrease obesity are no longer sensitive to leptin meaning they never feel full
Testicular Feminization/Androgen Insensitivity -- typical female genitals
thought to be typical female because breasts develop and hips broaden but menstruation does not occur because of internal testes rather than ovaries and uterus; pubic hair is sparse and vagina is short - Develops psychologically as female
Hormonal effects depend on
timing • prenatal (perinatal, too, for rodents) • puberty • throughout life
function of the digestive system
to break food down into smaller molecules that the cells can use - begins in the mouth where enzymes in the saliva break down carbohydrates and chewing mechanically breaks down food - swallowed food travels down the esophagus into the stomach, where it mixed with HCl and enzymes that digest proteins - the stomach stores food for a time then a round sphincter muscle opens at the end of the stomach to release food into the small intestine - the small intestine has enzymes that digest proteins, fats, and carbohydrates and absorbs digested materials into the bloodstream • duodenum, proteins, fats, carbohydrates, then • jejunum → where a lot of stuff that's broken down in duodenum is absorbed - the blood carries those chemicals to body cells that either use them or store them for later use - the large intestine absorbs water and minerals and lubricates the remaining materials to pass as feces
When LIP is suppressed through
training has no effect; learning does not occur
mice studies show
transferring intestinal microorganisms from lean mice into obese mice helps obese mice lose weight
immunization
tried by injecting amyloid proteins into the blood which are foreign so the body fights them off but people were dying from other problems so had to stop
female sex hormones
two X chromosomes
Taking melatonin pills is
unhelpful right before bed because the pineal gland is usually already secreting it at this time; must take it earlier and then the next day you will also go to bed early, shifting your circadian rhythm - Can be helpful for people who travel across time zones
delusions
unjustifiable beliefs
glucose
used as energy; stored as glycogen, then as triglycerides
buprenorphine and levomethadyl acetate
used to treat opiate addiction - LAAM produces a long-lasting effect so that a person visits a clinic 3 times a week instead of daily -- People using live longer and healthier and are far more likely to hold a job --- BUT doesn't end addiction just satisfies the craving in a less dangerous ways
function of a fever
using heat to try to kill off infection • 104/105 is dangerous because proteins begin to denature but low-grade fever is adaptive
CAH girls (XX) internal ductal system?
usually normal (but some may not menstruate)
Factors which ↑ or ↓ eating - Learning
usually what causes cravings except for salt/maybe proteins - When you eat (culture & time) - what you eat - how much you eat (culture & time)
side effects of drugs
vary between people
body reacts with hormones that constrict blood vessels
vasopressin and angiotensin II
receiving drugs during withdrawal is
very powerful - learn that drugs relieve stress • generalizes to all stressful situations
Factors which ↑ or ↓ eating - nutrients in intestines
via splanchnic nerve
Modeling/Observational learning
vicarious conditioning
Neural pathway for hypovolemic thirst
volumetric receptors → renin (from kidneys) → interacts with angiotensinogen to create angiotensin I → angiotensin II (too big to pass BBB) → vasoconstriction & → area adjoining 3rd ventricle → hypothalamus → angtiotensin II (in brain) → drinking behavior & → (with aldosterone) → modulate receptors on tongue & nucleus of solitary tract → salt appetite & → (with vasopressin) → vasoconstriction
Osmotic thirst Best Relieved by Drinking
water
semipermeable membrane
water can pass but solutes cannot
water is what percent of the body
water is ~70% of the mammalian body
REM may play a major role for...
weakening unnecessary synapses; deprivation results in deficits in learned motor tasks • vs. SWS & verbal memory • (rats) repeated REM deprivation after training session → learning more slowly • (rats) after training session = ↑ REM • ↑ REM corre. with ↑ performance • Once task is well-learned, REM ↓s to baseline levels
harder to adjust to jet lag going
west to east because we phase advance our circadian rhythms • biological clock is slower than environmental clock
Gender identity
what we consider ourselves to be
exogenous melatonin: repeated morning dose?
will probably help you stay awake
exogenous melatonin: afternoon dose?
will put you to sleep
Testicular Feminization/Androgen Insensitivity -- Internal ductal system
• No Wolffian system (but testes) - SRY gene causes primitive gonads to become testes but nothing else happens because androgens are not recognized by receptors so growth does not occur • No Müllerian system - testes are there so they produce MIH which causes the Mullein ducts to degenerate
Two major causes of Sleep Apnea
• Obstructive • central nervous system
pons
• Reticular Formation • Locus Coeruleus • Raphe Nucelus
If damage occurs early in life, why is onset later in life?
• actually, subtle signs even during childhood • prefrontal cortex matures more slowly
factors which feminize external genitalia
• alcohol • marijuana • haloperidol (antipsychotic medication) • estradiol - not so much feminization as it interferes with masculinization (e.g., malformation of prostate gland
weak or absent signs of emotion, speech, and socialization
• alogia • avolition • social disturbance • emotional disturbance • disturbance of working memory
Major depressive disorder: Associated features
• anhedonia is more critical symptom • females (2): males (1) • 10% lifetime prevalence
the lateral hypothalamus contributes to feeding in many ways
• axons from the lateral hypothalamus to the NTS, part of the taste pathways, alter the taste sensation and the salivation response to the tastes. When the lateral hypothalamus detects hunger, it sends messages that make the food taste better • axons from the lateral hypothalamus extend into several parts of the cerebral cortex, facilitating ingestion and swallowing and causing cortical cells to increase their response to taste, smell, or sight of food • the lateral hypothalamus increases the pituitary gland's secretion of hormones that increase insulin secretion • the lateral hypothalamus sends axons to the spinal cord, controlling autonomic responses such as digestive secretions. An animal with damage to the lateral hypothalamus has trouble digesting foods
Issues of Gender Assignment and Rearing: now thought best to
• be honest with intersex person and do nothing without their informed consent • identify the child as male or female based mainly on the predominant external appearance; don't just call them female • rear the child as consistently as possible but be prepared for different sexual orientations • do not perform surgery
endogenous circamonthly rhythm
• body temperature (females) • menstruation
Activation of the lateral hypothalamus can result in the following:
• changes in the nucleus of the solitary tract → perception that food is better tasting • changes in cerebral cortex → facilitating ingestion, response to food cues • activation of pituitary gland → increased insulin secretion • activation of ANS → increased digestive secretions
women though may gain from multiple partners
• could increase chances of becoming pregnant • second man could assist in childcare • could find a better mate
DA hypothesis of schizophrenia
• effectiveness of antipsychotic medications e.g. phenothiazines like chlorpromazine (Thorazine), butyrophenones like haloperidol (Haldol) - ~ 2 wks for effect - DA turnover is ↑ in some areas - drugs which release DA (e.g. various stimulants, LSD) = psychotic symptoms - but also 5-HT? (LSD) - 2X greater # of activated DA receptors in those with schizophrenia -- IBZM binds to vacant D2 receptors -- measuring radioactivity = count of D2 receptors -- AMPT to block DA synthesis -- IBZM again to count ALL D2 receptors -- IBZM 2nd count - IBZM 1st count = # of DA receptors usually occupied - another study: positive corre. between # of D2 receptors activated and level of cognitive impairment - But...drug effects are within hours while relief from symptoms takes 2-3 wks - AND, others have found the problem to be ↓ DA in prefrontal area (negative symptoms) & ↑ DA activity in nucleus accumbens (positive symptoms)
CBT and other forms of psychological therapy are often helpful
• equally helpful in the moment as antidepressants • BUT effects are more likely to last; relapse rates are lower
As such, Lashley proposed two principles about the nervous system
• equipotentiality • mass action
forms of energy and storage
• fat • amino acids • glucose
Prenatal and Neonatal Environment - Immediate risk Factors
• having a father over age 55 • living in a crowded city • toxoplasma gondii
Behavioral and Anatomical Differences of homosexuality - brain hemispheres
• heterosexual female & homosexual male: equal in size • heterosexual male: right > left • homosexual female: intermediate to heterosexual male & female
Behavioral and Anatomical Differences of homosexuality - amygdala
• heterosexual female & homosexual male: left has more widespread connections than right • heterosexual male: right has more connections than left • homosexual female: intermediate to heterosexual male & female
Behavioral and Anatomical Differences of homosexuality - INAH-3
• heterosexual male > heterosexual female/homosexual male • heterosexual males: more androgen receptors here AND larger neurons
heterosexual men are slightly taller and heavier than homosexual men
• heterosexual male > homosexual male • homosexual female > heterosexual female
Behavioral and Anatomical Differences of homosexuality - SCN
• homosexual male > heterosexual male • rats with mutation may prefer different mate depending on time of day • early in active period: both male & females • later in day: mostly females
factors contributing to obesity
• inactive lifestyle • fast food restaurants → cheap, fast, convenvient • large portion sizes • fake food • availability of food
LTP: repeated stimulation of presynaptic neuron
• increase glutamate release • Na+ influx (through AMPA) • depolarization of postsynaptic neuron • ejection of Mg+ (NMDA) • Ca++ influx & Na+ (NMDA) • activates CaMKII → CREB
PER and TIM cycle
• levels of messenger RNA responsible for producing PER and TIM are low early in the morning • levels increase during the day, increasing synthesis of proteins, but protein synthesis lags hours behind levels of messenger RNA • as PER and TIM concentrations increase, they feed back to inhibit the genes that produce the messenger RNA molecules • during the night, the PER and TIM concentrations are high, but the messenger RNA levels are declining • by morning, PER and TIM levels are low again and the cycle repeats
consolidation isn't what it was previously thought
• long term memory is not permanent → being reminded of an old memory brings it to life where it can be reconsolidated, altered, or weakened • time needed to consolidate varies enormously
brain has several different dopamine pathways
• mesolimbocortical system
evidence of abnormal metabolism of progesterone (↓ metabolism) in Premenstrual Dysphoric Disorder
• metabolites of progesterone modify GABA synapses, which are involved with controlling anxiety/stress responses • not a lot of progesterone means negative mood because gaba is not affected so anxiety/stress is not controlled
newborn mammals survive first on mother's milk but they stop nursing with age because...
• milk supply declines • mother pushes them away • they begin to eat other foods
Sexual behavior in humans
• more subtle effects of activation effects • also non-sexual effects
Native American Pima in Arizona and Mexico
• most Native American Pima in Arizona and Mexico are overweight and they have several genes for increased risks - in the past, Pima ate dessert fruit available only in certain times so they learned to overeat when they could - BUT weight was not a problem for then until they adopted a US diet that was constantly available
obesity
• now a problem due to increased availability of our diet and sedentary lifestyle • used to think obesity was caused by distress because food makes people happier but mood has only a weak relationship to weight gain • another factor is prenatal environment → exposure to high-fat diet before birth predisposes the offspring to increased appetite and body weight
amygdala and related areas send two kinds of input to the lateral hypothalamus
• one path → inhibits eating during illness and mediates aversion to foods previously associated with illness • second path → stimulates eating in response to highly tasty foods
treatments for sleep apnea
• operation to remove tissue obstructing the trachea • CPAP machine → mask that covers the nose and delivers air under enough pressure to keep the breathing passages open • lose weight, avoid alcohol & tranquilizers
orexin
• orexin has roles in wakefulness and two roles in feeding: - increases animals' persistence in seeking food - responds to incentives in general • stimulation of orexin receptors increases activity and motivation
Narcolepsy and orexin
• people with narcolepsy lack the hypothalamic cells that produce and release orexin • but narcolepsy cannot be treated with orexin directly because it does not readily cross the BBB and no effective drugs exist
fruit fly studies found several genes responsible for a circadian rhythm
• period gene (PER) → produces PER proteins • timeless gene (TIM) → produces TIM proteins
CAH girls...
• play with boys toys at levels in between boys and girls • do better that most other girls on spatial and mechanical skills • more likely to be interested in male activities and jobs as adolescents/adults
In-depth look at the role of the pons in REM sleep
• pons (peribrachial region) → lateral geniculate nucleus → occipital lobe (PGO waves) • pons (subcoerulear region) → spinal cord = inhibition of motor neurons
REM Sleep
• rapid eye movement • difficult to awaken; alert when woken up • EEG like Stage 1 sleep/awake • muscle atonia • associated with vivid, narrative dreams but REM sleep is not always tied to dreams - these two things can be uncoupled - dream most about sex, money, and violence - children dream most about animals • penile erection & ↑ vaginal secretions • aka paradoxical sleep → signs that suggest this is a deep form of sleep but also signs that suggest its kind of life being awake
Exercise
• regular, moderate-intensity exercise has moderate antidepressant effects, especially for those over age 60
sons of alcoholics...
• show less than average intoxication after drinking a moderate amount of alcohol • feel less drunk • show less body sway • have stress decreased more than others by drinking alcohol
Symptoms of Korsakoff's
• similar to those who have prefrontal damage • difficulties reasoning • confabulation • experience apathy, confusion, and memory loss; impairment of episodic memory but intact implicit memory
fatal insomnia?
• sleep disturbances leading to total insomnia, coma, then death • starts with severe sleeping problems, progresses to other brain issues • dying from sleep deprivation or something else wrong in the brain?
humans also use (and prefer) behavioral mechanisms of temperature regulation
• staying in temperature controlled environments • wearing more or less clothing • becoming more or less active • huddling with others
Differential Diagnosis of Schizophrenia
• substance abuse → stimulants, LSD, phencyclidine can produce hallucinations, usually visual, or delusions • brain damage • undetected hearing deficits → people starting to have trouble hearing may think everyone is whispering about them • Huntington's disease → delusions, hallucinations, disordered thinking, and motor abnormalities • nutritional abnormalities → can produce hallucinations and delusions (e.g. niacin, vitamin C deficiency, or allergy to milk proteins (not lactose), even some with gluten intolerance) • mood disorder with psychotic features
how do satiety mechanisms work
• swallowing & water content of stomach → anterior cingulated cortex → satiation • lamina terminalis is still active → because they have not yet absorbed the water you have been drinking
(SWS) destruction of free radicals?
• task that demands alertness = ↑ delta activity during sleep • stim. hand with vibrator = ↑ delta activity in that somatosensory region • ↑ mental activity (but NOT physical exertion) for a day → readily falling asleep & ↑ SWS during sleep • exercising didn't make people fall asleep more readily but cognitive exercise did • SWS waves concentrated in areas that had had high mental activity- must be restorative
POA/AH integrates several types of information, receiving input from...
• temperature receptors in the skin, organs, and brain • the immune system
unusual conditions include...
• the brain is getting little information from the sense organs so it is free to generate senses (sight, etc.) without constraints or interference • primary motor cortex is suppressed so arousal cannot lead to action • activity is suppressed in the prefrontal cortex so dreams are often forgotten and we lose our sense of volition/planning • activity is high in the inferior parietal cortex, an area important for Visuospatial perception • activity is high in the amygdala, hypothalamus, and other areas important for emotions and motivation
Memory consolidation (during sleep & rest) may be due to replay
• thinking about a lot, create synapses, brain more likely to take note of and practice • if anything cues having done the task in the middle of the night, brain will practice
What other factors are involved (besides the hippocampus)?
• time • emotions
Types of Antidepressants
• tricyclics • SSRIs (Selective Serotonin Reuptake Inhibitors) • MAOIs (Monoamine Oxidase Inhibitors) • Atypical Antidepressants • St. John's Wort
high fructose corn syrup
• whereas glucose stimulates release of leptin and insulin that help reduce hunger, fructose has little effect on leptin or insulin so drinking something with fructose means you gain calories without feeling satiated • if you drink fructose its also mostly stored as fat
CAH girls?
• ↑ asexualism • ↑ homosexual fantasies or NO sexual fantasies • ↑ rates of homosexual orientation, though most are still heterosexual (though perhaps non-practicing)
osmotic receptors
• → hypothalamus (e.g., supraoptic nucleus & paraventricular nucleus) → posterior pituitary (secretes vasopressin, leading to vasoconstriction, retention of sodium & water) • → lateral preoptic area (leading to drinking behavior)
hallucinations corre. with
↑ activity in thalamus, hippocampus, & cortical areas involved with hearing
testosterone + estradiol primes brain areas to
↑ dopamine release - which leads to erection - increased likelihood of copulation (male) - sexual posture (females) (mostly referring to rats) - orgasm (higher doses) - resembles drug rush
sleep after learning task
↑ memory consolidation of task • reminders of new learning (during sleep) can ↑ chances of memory consolidation of that new learning • ↑s creativity & chances of aha! Moments
+ negative life events
↑ rate of depression
sex hormones
↑ responses of VMH, medial preoptic area, anterior hypothalamus, sexually dimorphic nucleus
↓ testosterone in older men
↑ risk of depression
having relatives with early onset depression
↑ risk of depression • earlier age of onset
estrogen
↑ sensitivity of pudendal nerve which has role in pelvic area
impotence
→ the inability to have an erection • Usually caused by impaired blood circulation not low testosterone
antioxidants
↓ Aβ42 production - curcumin - do not know why antioxidants are helpful but they are
total sleep deprivation =
↓ depression - quickest - ↑ proliferation of hippocampal neurons - selective sleep deprivation → depriving people of REM
non-sexual effects of estrogen & testosterone in humans
↓ pain & anxiety
• ↓ testosterone (e.g., castration) =
↓ sexual interest/activity
