Term
| What is most energy in the body stored as? |
|
Definition
| FAT - changes in body weight largely due to changes in fat |
|
|
Term
| Why is fat preferred method of energy storage? |
|
Definition
Highest energy density (9kcal/g) of macromolecules
Also holds less water than glycogen (don't need as much water weight w/ it) |
|
|
Term
| What are the 3 digestive phases of energy metabolism? |
|
Definition
| Cephalic, Absorptive, Fasting Phases |
|
|
Term
| When does the cephalic phase of digestion end? |
|
Definition
| When nutrients are absorbed into the blood stream (begins before food is ingested) |
|
|
Term
| 3 main functions of insulin? |
|
Definition
Promote use of glucose as energy source
Lipogenesis & protein synthesis - promotes energy storage
Promotes storage of liver & myscle glycogen |
|
|
Term
|
Definition
| People attribute hunger to presence of an energy deficit - eating corrects deficit to return to correct energy set point |
|
|
Term
|
Definition
| Believe there is a defined glucose set point; hungry if below set point; satiated if at or above |
|
|
Term
| Evidence for the lipostatic theory of hunger? |
|
Definition
| Body weights of adults stays relatively constant; b/c of the set point for amount of body fat, little change in overall weight |
|
|
Term
| What are 3 major weaknesses of set point theories? |
|
Definition
Current obesity epidemic
Inconsistent with basic eating related evolutionary pressure - need to be able to eat lots in times of plenty (store extra kcal)
Fail to recognize major influences of social & learning influences (environmental factors) |
|
|
Term
| What is the central assertion of the positive incentive theory? |
|
Definition
Animals are NOT driven to eat due to internal energy deficits
Animals ARE drive to eat by the anticipated pleasure that will be derived from it - we eat because of positive-incentive value of food (anticipated pleasure) |
|
|
Term
| According to the positive-incentive approach, what influences the degree of hunger felt? |
|
Definition
| ALL factors that affect the food's positive incentive value (flavor, social experience with food, social setting, time since last eating, etc.) |
|
|
Term
| According to the phases of digestion, when are two small peaks in insulin levels observed? |
|
Definition
During cephalic (preparatory) and digestive phases
During absorptive phase see LARGE, GRADUAL increase in insulin levels (drops into fasting phase) |
|
|
Term
| How does glucagon get energy out of fats? |
|
Definition
| During prolonged energy starvation, lipolysis occurs to convert fatty acids into ketone bodies (used by muscles & brain as energy) |
|
|
Term
| Difference between insulin transport in neurons vs. other cells? |
|
Definition
| Neurons DO NOT require presence of insulin to uptake glucose |
|
|
Term
| Preferences with sweet & fatty foods? Salty foods? |
|
Definition
Evolutionarily evolved to EAT & LIKE these flavors
Sweet & fatty = high kcal content (energy)
Salty = lots of Na+ to maintain osmolarity |
|
|
Term
| What is one typical flavour aversion in eating? |
|
Definition
| BITTER = usually associated with toxic foods |
|
|
Term
| Getting hungry at routine mealtimes has to do with the _______ phase of eating? |
|
Definition
| CEPHALIC (body prepares itself for food before food has even been ingested) |
|
|
Term
| Hunger at the cephalic phase of eating represents a ______________ |
|
Definition
|
|
Term
| Weingarten experiment - initiation of cephalic phase of eating? |
|
Definition
Cephalic phase initiation can be conditioned - 6 small meals/day each paired with buzzer/light cue
When given continuous food access, initiated consumption by turning on buzzer independent on amount of time between meals |
|
|
Term
| What tastes have an inherently high positive-incentive value? |
|
Definition
| FATTY, SWEET & SALTY foods |
|
|
Term
| How do we learn to eat minerals that have no taste? |
|
Definition
Need to associate positive effects (health) of consuming diet with mineral/vitamin and gain positive incentive value based on that
Associate diet rich in mineral w/ good health - therefore develop preference to this diet |
|
|
Term
| Most animals choose to eat ___________ throughout day if given unlimited food access |
|
Definition
|
|
Term
| What is mealtime hunger caused by? |
|
Definition
| EXPECTATION of food -> body prepares for disruption of homeostasis by entering cephalic phase of digestion (meal = stress for the body) |
|
|
Term
| What two factors do satiety signals in the body depend on? |
|
Definition
VOLUME of the meal
Caloric/nutritive density of the food (kcal/volume of food) |
|
|
Term
| Sham eating experiments & set point hunger theories? |
|
Definition
Sham eating - food never makes it to stomach despite being chewed & swallowed
2 diets for rats, 1 new, 1 old
Old diet - 1st meal was same size, then meals got bigger and bigger
New diet - rats ate large quantities right from beginning
AMOUNT EATING BASED ON PREVIOUS EXPERIENCE WITH FOOD |
|
|
Term
|
Definition
| Small amounts of food eaten before a meal can increase hunger (initiation of cephalic phase) |
|
|
Term
| What happens as you eat lots of the same type of food? |
|
Definition
| Positive incentive value of that food decreases, PI value of all other foods increases (sensory specific satiety) |
|
|
Term
| Differences in short term vs. long term changes in PI value of a food when eating? |
|
Definition
Immediate sensory specific PI decrease in all foods of the same flavour (taste receptor mediated)
Later, have a general decrease in PI of all food (signals during digestion) |
|
|
Term
| What foods are immune to the enduring effects of sensory specific satiety? |
|
Definition
| Rice, bread, potatoes, sweets (evolutionarily foods we ate very often and used to obtain lots of energy) |
|
|
Term
| Advantages of SS satiety? |
|
Definition
Encourages a variety in the diet
Encourages us to eat lots in times of plenty |
|
|
Term
| Premeal decrease in blood glucose is __________ to intention to start eating |
|
Definition
"a response"
The drop in glucose does not precede intention to eat; first have intention to eat, enter cephalic phase, then get drop in blood glucose |
|
|
Term
| What was previously thought to be the satiety centre in the brain? |
|
Definition
|
|
Term
| Bilateral lesions to the VMH cause.... |
|
Definition
|
|
Term
| 2 phases of VMH syndrome? |
|
Definition
Dynamic - several weeks of excessive eating & weight gain
Static - decline in consumption; maintain new obese body weight |
|
|
Term
| Bilateral lesions to the VMH cause _____, _______, and decline in ________ levels |
|
Definition
Obesity, Hyperphagia
Increase in insulin levels - get increased lipogenesis & decreased lipolysis; animal "stuck in absorptive phase" of digestion |
|
|
Term
| What other structures are implicated in the VMH regulation of satiety? |
|
Definition
Ventral noradregenergic bundle (VN bundle)
Paraventricular nucleus (PVN)
Lesions to VN bundle & PVN also cause same hyperphagia/obesity as VMH lesions |
|
|
Term
| What was considered to be the "feeding centre"? |
|
Definition
| Lateral hypothalamus (LH) |
|
|
Term
| Bilateral lesions to the LH cause... |
|
Definition
|
|
Term
| Two features of LH syndrome: |
|
Definition
Aphagia was accompanied by adipsia
LH lesioned rats recovered if kept alive by feeding tube for short period - regained eating & drinking habits |
|
|
Term
| LH lesions cause aphagia, as well as... |
|
Definition
| Motor disturbances, lack of responsiveness to sensory input |
|
|
Term
| Cannon & Washburn theory of hunger (U-tube swallowing experiment)? |
|
Definition
| Thought pangs of hunger were caused by stomach contractions & satiety was the feeling of stomach distension |
|
|
Term
| Examples of satiety peptides? |
|
Definition
| CCK, somatostatin, glucagon |
|
|
Term
| Examples of hunger peptides? |
|
Definition
| NPY, ghrelin, orexin, galanin |
|
|
Term
| What are 3 properties of 5-HT induced satiety? |
|
Definition
Can resist cafeteria diets with high palatability
Reduced food consumed in given meal, not # of meals
Shift preference away from fatty foods |
|
|
Term
|
Definition
Insatiable hunger; little to no satiety
Deletion of chr 15 from father |
|
|
Term
| T or F - Excess calorie consumption, independent of fat accumulation, is proven to be detrimental to health? |
|
Definition
|
|
Term
| What is weight loss vs. weight gain limited by? |
|
Definition
Weight loss limited by INCREASED efficiency of energy use
Weight gain limited by DECREASED efficiency of energy use |
|
|
Term
| What happens to body temperature when body fat increases? |
|
Definition
| T increases also (due to diet induced thermogenesis) |
|
|
Term
| Difference from set point & settling point models? |
|
Definition
Set point - negative feedback brings system back to set point (unchanging)
Settling point - negative feedback prevents further changes in the system |
|
|
Term
| Leaky Barrel Model Analogues... |
|
Definition
Water in hose - amount of food available
Water pressure - +ve incentive value
Water entering - food consumed
Water level in barrel - amount of body fat
Weight of barrel on hose = strength of satiety signal |
|
|
Term
| What is most energy expenditure on a daily basis due to? |
|
Definition
Basal metabolic rate
Exercise actually accounts for a small portion of expenditure, b/c bodies are so efficient, few calories are burned during a workout |
|
|
Term
| Leptin KO mice are called? |
|
Definition
| ob/ob mice - defective leptin gene (expressed only in adipocytes) |
|
|
Term
| What are the different types of fat believed to be regulated by leptin vs. insulin? |
|
Definition
Leptin = subcutaneous fat
Insulin = visceral (truncal) fat |
|
|
Term
| Where are receptors for leptin & insulin most highly concentrated? |
|
Definition
| In the arcuate (ARC) nucleus of the hypothalamus |
|
|
Term
| What classes of neurons are leptin & insulin receptors at their highest density? Where are these neurons located? |
|
Definition
NPY neurons & melanocortin neurons
Both concentrated to the greatest extent in the ARC nucleus of the hypothalamus |
|
|
Term
| ______ agonists have been shown to be useful in treating obesity |
|
Definition
|
|
Term
| Most commonly prescribed bariatric sx is? |
|
Definition
|
|
Term
| How can AN and BN be seen as different sides of the same disorder? |
|
Definition
Both start with improper perception of body weight w/ obsession to lose weight
Many patients straddle the diagnosis between the two throughout the course of the disease(s)
Both highly correlated with OCD, depression; found most often in affluent cultural groups |
|
|
Term
| What is the association between AN and the perceived +ve incentive value of the food? |
|
Definition
According to +ve incentive perspective - decrease in eating, is due to decrease in +ve incentive value of food
Believe that +ve incentive value of taste is lower in anorexics than in control group (even though anorexics seem obsessed with food, +ve incentive is different when thinking about vs. actually eating the food) |
|
|
Term
| Where do hypothalamic NPY neurons project to? |
|
Definition
PVN - believed to be implicated in energy metabolism; part of VMH satiety circuit
LH - feeding regulation; part of feeding centre circuit |
|
|
Term
| Infusions of NPY directly into the PVN cause... |
|
Definition
| Increased insulin release - increased lipogenesis & reduced lipolysis; however, only a MODEST increase in food intake |
|
|
Term
| Infusions of NPY directly into LH cause... |
|
Definition
HUGE increase in food intake in all rats w/ increased motivation to obtain food (may increase +ve incentive value)
Blocks conditioned response of being full - will continue to eat; increased consumption of bitter foods |
|
|
Term
| Brown et al -> NPY break point experiment... |
|
Definition
Had cannulae implanted so NPY could directly be infused into the LH (should cause massive increase in intake)
NPY infusions caused increase in break point in dose dependent manner - increased motivation to obtain food (increase in break point = increase in motivation) |
|
|
Term
| What happens to mRNA levels of NPY during times of starvation...? |
|
Definition
See INCREASED mRNA when starved
See DECREASED mRNA when eating/satiated |
|
|
Term
| BMI measures and relative weights,,, |
|
Definition
< 18.5 = underweight
18.5-25 = healthy
> 30 = obese |
|
|
Term
| In age groups below age of 75, obesity is more prevalent in... |
|
Definition
|
|
Term
| In terms of socioeconomic status, obesity was more common in _______ |
|
Definition
| Low SES groups (eat more fast food, more poverty, etc.) |
|
|
Term
| Vermont obesity prison study |
|
Definition
Increased 3500 extra kcal/day for 6 months; average weight gain of 40 lbs
When back on normal diet, most inmates lost the weight; those who didnt had a fam history of obesity |
|
|
Term
| What two classes of neurons are affected by leptin in the ARC nucleus? What are its effects on these neurons? |
|
Definition
NPY - INHIBITS NPY containing cells (NPY increases eating behaviors; leptin acts to satiate)
POMC neurons - activates POMC neurons |
|
|
Term
| Leptin can enter the brain via __________ system |
|
Definition
Active transporter
Obesity may be caused by mutations in leptin transport (in obese individuals had 318% normal plasma levels, but only 30% of normal levels in CSF) |
|
|
Term
| BMI in anorexia nervosa is... |
|
Definition
| < 17.5 (<85% of ideal body weight for height/age) |
|
|
Term
| Leptin concentrations in anorexics are _______ than in controls |
|
Definition
LOWER (less fat = less leptin?)
AFTER TREATMENT, leptin concentrations exceed those in healthy controls |
|
|
Term
| Different strains of mice used to model AN - stressed vs. relaxed? |
|
Definition
Relaxed = C57BL
Anxious = DBA |
|
|
Term
| Rat experiment to model vulnerability to activity induced anorexia... |
|
Definition
Baseline - unlimited food access for 5 days
Treatment - restrict access to 2 hrs/day
DBA (anxious mice) - lost more weight across treatment period; two groups DID NOT significantly differ in food intake
DBA mice ran more on the wheel; both showed decrease in leptin levels, but decrease was greater in DBA (anxious mice)
Negative correlation between wheel running & circulating leptin levels only seen in anxious (DBA) mice
Leptin prevents food restriction induced exercises in wheel running |
|
|
Term
| How can leptin act to inhibit food restriction induced exercise? |
|
Definition
Inhibition of DA signalling
Nigrostriatal path - locomotion (SN to striatum)
Mesolimbic path - reward & addiction (VTA to nucleus accumbens) |
|
|
Term
| What is pimozide used to treat in humans? |
|
Definition
DA-2 antagonist - used to treat anorexics
Reduce DA signalling in the nigrostriatal pathway to inhibit food restriction induced exercise |
|
|
Term
| Nigrostriatal vs mesolimbic path |
|
Definition
Nigrostiratal = locomotion; SN to striatum
Mesolimbic = reward, addiction; VTA to N accumbens |
|
|
Term
| When does sexual differentiation occur (primordial gonads differentiate)? |
|
Definition
| at 6-7 weeks post-conception |
|
|
Term
| What triggers sexual differentiation in males vs. females? |
|
Definition
At 7 weeks, SRY gene on Y chr synthesizes SRY protein
If SRY protein present - get testes
If SRY protein absent - get ovaries |
|
|
Term
| What do the Wolffian ducts become in males? |
|
Definition
| Seminal vesicles, vas deferens, epididymis |
|
|
Term
| What do the Mullerian ducts become in females? |
|
Definition
| Fallopian tubes, uterus, inner 2/3 of vagina |
|
|
Term
| Difference in male vs. female patterns of gonadal hormone release? |
|
Definition
Females = CYCLICAL (cycle of about 28 days)
Males = STEADY (little change day to day)
Pituitary transplants between genders show that the pituitary is NOT inherently male or female - controlled elsewhere |
|
|
Term
| Hormones released by posterior pituitary? |
|
Definition
| ADH & oxytocin (synthesized in PVN and SON in hypothalamus) |
|
|
Term
| What was the 1st isolated hypothalamic releasing hormone? |
|
Definition
| TRH - thyrotropin releasing hormone |
|
|
Term
| What is the only endocrine gland that is not directly regulated by neural input? |
|
Definition
ANTERIOR PITUITARY
Controlled by hypophyseal portal system |
|
|
Term
| Hormones tend to be released in a _______ fashion |
|
Definition
|
|
Term
| Primordial gonads - if SRY protein is present, the _______ of the gonads develops into the ________ |
|
Definition
| MEDULLA of primordial gonads develops into TESTES |
|
|
Term
| If SRY protein is absence, the _______ of the primordial gonad develops into a _______ |
|
Definition
| The CORTEX of the primordial gonad develops into an OVARY |
|
|
Term
| When do the testes begin secreting testosterone & MI substance? |
|
Definition
| At 3 months post conception |
|
|
Term
| The external genitalia of males and females comes about from a _______ precursor |
|
Definition
|
|
Term
| 4 main parts of bipotential external genitalia before differentiation? |
|
Definition
Glans
Urogenital Fold
Lateral Bodies
Labioscrotal Swellings |
|
|
Term
| The external genitalia of males forms from the precursor in the following manner.... |
|
Definition
Glans = head of penis
Lateral bodies = shaft of penis
Labioscrotal swellings = scrotum
Urogenital fold = urethra |
|
|
Term
| The external genitalia of females forms from the precursor in the following manner.... |
|
Definition
Glans = clitoris
Lateral bodies = hood of clitoris
Labioscrotal folds = labia majora
Urogenital fold = labia minora |
|
|
Term
| What causes differentiation of external genitalia in males vs. females? |
|
Definition
Males - presence of testosterone/DHT causes scrotal/penile development
Females - absence of testosterone/DHT causes vaginal, clitoral, and labial development |
|
|
Term
| What differentiates first, external or internal genitalia? |
|
Definition
EXTERNAL differentiates first
EXTERNAL = 2 months
INTERNAL = 3 months |
|
|
Term
| Average age of puberty in boys & girls? |
|
Definition
|
|
Term
| Where is androstenedione released and what is it responsible for? |
|
Definition
Released from adrenal cortex
Causes pubic & axillary hair growth in FEMALES predominantly |
|
|
Term
| Gonadectomy of prenatal rats of either gender caused them to develop into a ______________ of hormone release |
|
Definition
| CYCLICAL PATTERN (female) |
|
|
Term
| The inherent pattern of hormone release appears to be _______ |
|
Definition
| Cyclical (gonadectomy causes female cyclic pattern; only blocked when testes are transplanted in - then causes steady male pattern) |
|
|
Term
|
Definition
| Aromatase converts testosterone to estradiol (type of estrogen); brain is masculinzed by estradiol that has been converted from testosterone in neurons |
|
|
Term
| How do genetic females whose brains are supposedly masculinized by estradiol prevent masculinization of the brain by their mothers' circulating estradiol? |
|
Definition
| Alpha-fetoprotein - binds circulating estradiol in the fetus' blood (present in fetal blood supply) |
|
|
Term
| Genotype in androgen insensitivity syndrome? |
|
Definition
|
|
Term
| What is the mutation in Androgen Insensitivity Syndrome? |
|
Definition
Mutated androgen receptor - genetically male, but androgens cannot exert effects
Have testes, but no internal reproductive ducts - lack of testosterone binding and MI substance still produced
External genitalia can be female or ambiguous depending on mutation severity
X-linked pattern of inheritance |
|
|
Term
| What is Congenital Adrenal Hyperplasia? |
|
Definition
Cortisol deficiency leads to overactive adrenal cortex leading to excessive androgen production
Causes accelerated puberty in males or androgenital syndrome in females |
|
|
Term
| What causes androgenital syndrome in females? |
|
Definition
Caused by congenital adrenal hyperplasia - excess androgen release from adrenal cortex
Genotypically female (normal ovaries & internal female organs); may have ambiguous genitalia
Secondary sex characteristics depend on which hormone predominates |
|
|
Term
|
Definition
45 XO Genotype
NO GONADS - only have 1 X chromosome
Mullerian system develops into internal female genitalia; also have external female genitalia (lack of testosterone)
NO estrogen release at puberty = no secondary sex characteristics
Treament = estrogen therapy; in vitro pregnancy |
|
|
Term
|
Definition
47 XXY
Enlarged breasts, sparse facial hair, small testes
Still should be genotypically male (ish) |
|
|
Term
| Where is the sexually dimorphic nucleus located? |
|
Definition
| In the medial preoptic area (MPA) |
|
|
Term
| Size of sexually dimorphic nucleus in males vs. females? |
|
Definition
| Appears to be 3-7x larger in males; positively correlates with testosterone levels |
|
|
Term
| If testosterone is injected into neonatal female rats, what happens to SDN size? |
|
Definition
| It increases (SDN = sexually dimorphic nucleus) |
|
|
Term
| Male type rodent sexual behaviours |
|
Definition
Mounting
Intromission
Ejaculation
Pelvic thrusting |
|
|
Term
| Female type rodent sexual behaviours? |
|
Definition
Lordosis = receptive behaviour
Hopping & ear wiggling = proceptive behaviour |
|
|
Term
| Lesions to the MPO area cause... |
|
Definition
Disruptions to male-type sexual behaviours in BOTH sexes
Contrastingly, stimulation increases these same behaviours |
|
|
Term
| What happens to MPO activity during copulation? |
|
Definition
| It increases (responsible for male-type sexual behaviours) |
|
|
Term
| What neurotransmitter is involved in the MPO area regulation of sexual behaviour? |
|
Definition
DA - excitatory for MPO area neurons
Testosterone binding to MPO area stimulates DA release in both males & females |
|
|
Term
| What is the estrous cycle? |
|
Definition
| Cycle of sexual receptivity lasting 12 to 18 hours (female is fertile, receptive & proceptive for sex) |
|
|
Term
| What is believed to initiate the estrous cycle |
|
Definition
| Increase in estrogen levels, followed by progesterone surge (as is seen right before ovulation) |
|
|
Term
| Why do human women differ from other female mammals in sexual behaviour? |
|
Definition
| Female primates are motivated to copulate during periods of NON-FERTILITY |
|
|
Term
| Female primate sex drive is believed to be regulated by... |
|
Definition
| ANDROGENS - testosterone replacement injections in females increase perceptivity; sex motivation correlates with testosterone, NOT estrogen levels |
|
|
Term
| DA input to the MPO area comes from the ______ |
|
Definition
Medial amygdala
Lesions to med amygdala reduce male type sexual behavior (just like MPOA lesions) |
|
|
Term
| Where does the MPO area send its efferents to? |
|
Definition
| The LATERAL TEGMENTAL AREA (LTA) - blocking this efferent output also decreases male-type sexual behaviour |
|
|
Term
| 3 structures implicated in controlling male-type sexual behaviour |
|
Definition
MPO area
Lateral tegmental area
Medial amygdala |
|
|
Term
| What structures are implicated in controlling female-type sexual behaviour? |
|
Definition
Ventromedial nucleus of hypothalamus (VMN); lesions block lordosis
Periaqueductal grey (PAG) - lesions block female sex behaviour |
|
|
Term
| Perinatal castration increases the preference for _______ partners |
|
Definition
|
|
Term
| Perinatal testosterone exposure in females generally creates a preference for ___________ partners |
|
Definition
|
|
Term
| Fraternal Birth Order Effect |
|
Definition
| Probability of male being homosexual increases as he is later in fraternal birth order (more older brothers = greater effect) |
|
|
Term
| Maternal Immune Hypothesis |
|
Definition
| Goes hand in hand with fraternal birth order effect; mothers become more immune to masculinizing hormones in male fetuses - immune system deactivates masculinizing hormones in younger sons |
|
|
Term
| In a typical 90 minute sleep cycle, what is the average time spent in REM vs NREM sleep? |
|
Definition
REM = 30 mins
NREM = 60 mins |
|
|
Term
| The longer you sleep, the ________ REM sleep you get per cycle |
|
Definition
| MORE (get proportionally more REM sleep if you sleep longer) |
|
|
Term
| What EEG waves are present during wakefulness? |
|
Definition
| BETA-waves (low voltage high frequency) |
|
|
Term
| What EEG waves are present during stage 1 sleep? |
|
Definition
| ALPHA-waves (8-12 Hz; slower frequency than B-waves) |
|
|
Term
| When do sleep spindles & K complexes become apparent? |
|
Definition
|
|
Term
| Description of what sleep spindles & K complexes look like |
|
Definition
Sleep Spindle = 1-2 wax and waning burst of higher frequency waves (12-14 Hz); believed to keep people asleep
K Complex = negative wave followed by positive wave; |
|
|
Term
| What marks the beginning of stage 3 sleep? |
|
Definition
| Intermittent presence of delta-waves (highest voltage, smallest frequency) |
|
|
Term
|
Definition
|
|
Term
EEG profile for REM sleep?
EMG profile for REM? |
|
Definition
EEG - Very similar to awake state (low voltage, high frequency waves)
EMG - complete absence of core muscle tone; paradoxical sleep - EOG and EEG readings suggest wakefulness, but EMG suggests otherwise |
|
|
Term
| Dreams from NREM vs. REM sleep? |
|
Definition
NREM - dreams as isolated experiences
REM - dreams as stories/narratives; more likely to remember REM dreams if awoken |
|
|
Term
| True or False - Beliefs that external stimuli can be incorporated into dreams? |
|
Definition
| TRUE DAT - water experiment |
|
|
Term
| In terms of the timing of dreams, they tend to last... |
|
Definition
| AS LONG AS REAL TIME (dreams run in real time) |
|
|
Term
| When is sleep walking (somnambulism) most common? |
|
Definition
| During SWS (stage 3 + 4); NEVER during REM b/c of muscle atonia |
|
|
Term
| Hobson's Activation-Synthesis Theory of Dreaming? |
|
Definition
| Brainstem circuits bombard cortex with input; random info supplied to cortex this way, dreams are a way of the cortex trying to make sense of this input |
|
|
Term
| Difference between manifest & latent dreams? |
|
Definition
Manifest dreams = dreams we experience
Latent dreams = disguised versions of real dreams |
|
|
Term
| Proposed functions of sleep? |
|
Definition
Energy conservation - small rodents need to sleep to lower metabolism and conserve energy; sloth refutes this idea
Predator avoidance - rodents are mainly nocturnal
Restoration & homeostasis - replenish lost biochemicals when sleeping
Important for learning & memory |
|
|
Term
| Sleep & procedural memory |
|
Definition
Learn finger tapping task, go and sleep and come back
Task performance improves after sleep; effects retained whether you learn task in morning or night (sleep helps improve task performance) |
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Term
| Sleep & declarative memory |
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Definition
Learn word pairs and either recall at night same day or after sleep the next morning - sleep performed much better
Interference condition - learn new list; interference was less effective after the sleep condition; sleep helps protect against interference |
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Term
| Sleep, memory consolidation & hippocampus... |
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Definition
Animals trained in novel maze - have hippocampal place cells that fire in a sequence to match location in maze; cells only fire when mouse is in certain location (sequential activation as mouse progresses through)
During SWS, see place cells fire off in correct order - place cells "replay the routes" of the maze to learn in a temporally more rapid manner (fast forward through them) |
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Term
| Sleep & hippocampus w/ cues in humans... (list 4 groups used in study)... |
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Definition
#1 - odour during learning; during sleep get odor/random vehicle
#2 - NO odour during learning; odor/random vehicle during SWS
#3 - Odour during learning; odor/random vehicle during REM
#4 - odor during learning; odor/vehicle during waking before sleep |
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Term
| Effects of odor cue paired with learning & sleep/hippocampus experiment... |
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Definition
Odor during learning AND during SWS enhanced recall
Odor during learning AND during REM had NO EFFECT
Compared to odor when waking, odor during SWS had better L hippocampus activation & enhanced recall |
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Term
| 3 main predictions of sleep deprivation according to Recuperation Theories: |
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Definition
Long periods of wakefulness lead to significant disturbances from homeostasis
Disturbances worsen as deprivation continues
After deprivation, much of the lost sleep will be regained |
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Term
| 3 main consistent effects of moderate sleep deprivation... |
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Definition
Increased sleepiness - also decreased sleep latency
Negative affect on tests of mood
Poor performance on tests of vigilance |
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Term
| The most susceptible cognitive functions to sleep deprivation are those involved in ________ |
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Definition
| Executive function - insightful thinking, incorporating new information into plans, etc. |
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Term
| Effects of sleep deprivation on immune system... |
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Definition
| Those who slept less were NOT more likely to be infected, but were more likely to develop symptoms |
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Term
| A _______ degree of catch up sleep is required to reverse negative consequences of sleep deprivation |
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Definition
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Term
| Sleep deprivation & verbal learning |
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Definition
Tested FREE RECALL & RECOGNITION
Sleep deprivation had impaired free recall, but no affect in recognition
Decreased temporal lobe activation; increased PFC and parietal cortex activation in sleep deprived (compensatory mechanism for temporal lobe) |
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Term
| In tests of free recall, those who were sleep deprived showed increased activity in the ____________ and decreased activity in the __________ |
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Definition
Increased = PFC & parietal cortex
Decreased = temporal lobe |
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Term
| Sleep deprivation & serial subtraction.... |
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Definition
Sleep deprived group had fewer correct responses compared to control
Decreased PFC & parietal activity (opposite as verbal learning task; PFC & parietal activation is task dependent) |
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Term
| Is sleep before learning important for encoding new memories? |
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Definition
| See memory performance decline in sleep deprived; see decreased hippocampal activation in sleep deprived group (impaired recognition & decreased hippocampal activation correlated) |
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Term
| What does cytokine IL-6 measure? |
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Definition
| Levels of systemic inflammation |
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Term
| Blood testing in sleep deprivation conditions with IL-6? |
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Definition
See increased IL-6 levels at end of sleep restriction period
Increased IL-6 levels associated with DMII, CVD & osteoporosis
IL-6 levels elevated only when awake; drop down to match controls when sleeping; levels spike at END of sleep restriction period |
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Term
| REM sleep deprivation has 2 consistent effects? |
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Definition
See REM rebound - more than usual amount of REM sleep for first 2-3 nights afterwards
With each successive deprivation, body tries to get more REM sleep (greater tendency to initiate REM sleep) |
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Term
| Difference in compensatory effects of REM sleep vs. SWS? |
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Definition
REM - see REM rebound following REM deprivation
SWS - see no real compensatory effect afterwards
Therefore, likely regulated in a different manner |
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Term
| Default Theory of REM Sleep |
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Definition
It is hard for the body to stay in NREM sleep, so brain switches to one of two other states - wakes up (if immediate bodily need) or goes to REM (no immediate need)
REM sleep and wakefulness are very similar in nature
Can substitute REM sleep with wakefulness as they are both similar in nature |
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Term
| What does sleep deprivation do to sleep efficiency? |
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Definition
It increases efficiency
Deprived individuals have a higher proportion of SWS during sleeping (restorative sleep) |
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Term
| Effects of modest sleep deprivation on psychomotor vigilance task? |
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Definition
| Sleep deprivation increased # of lapses & slowed reaction times (decreased vigilance) |
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Term
| Sleep & spatial memory... |
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Definition
Learning occurred at same rate in both groups (control & deprived)
Sleep deprived rats had poor memory retention during probe test (probe for water maze test they had learned)
Measured levels of phosphorylated (active) ERK - extracellular signal-regulated kinase via Western blot |
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Term
| ERK levels in sleep deprived vs. control rats in spatial memory test |
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Definition
Only saw significant decrease in ERK in 6 hours deprived condition (no real difference in 3 hr condition or in the 6 hr + 2 recovery)
ERK is implicated in LTP - so less ERK = less LTP = worse spatial memory performance |
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Term
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Definition
In mid-life develop insomnia, progressing towards total or near total inability to sleep
Die within 7-24 months post insomnia onset
Severe loss of neurons & glia in THALAMUS - mediodorsal & anterior nuclei |
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Term
| In free running cycles, see a _______ correlation between time spent awake and subsequent sleep |
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Definition
NEGATIVE
Because cycle is stuck at 25 hours - if you spend more time awake, you get less time to sleep |
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Term
| T or F - Pacemaker activity of the SCN is dependent on activity elsewhere in the brain |
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Definition
| FALSE - inherent to SCN neurons |
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Term
| What is responsible for both the free-running and zeitgeber induced circadian cycles? |
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Definition
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Term
| When is SCN activity at its peak? |
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Definition
During SLEEP portion of cycle
Lowest activity during WAKE portion of cycle |
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Term
| What happens to cycles of body temperature & sleeping/waking when housed in constant external environments? |
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Definition
They tend to show internal desynchronization - cycles break apart
Normally, they coincide with each other, but in the absence of external cues they desynchronize |
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Term
| What happens to the phase when flying east vs. west? |
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Definition
Flying east = phase advances (zeitgebers accelerated)
Flying west = phase delays (zeitgebers decelerated) |
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Term
| What are easier to adapt to, phase delays or advances? |
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Definition
PHASE DELAYS are easier to adapt to - better to schedule phase delays for shift workers
Easier to go to bed and wake up later, than go to bed and wake up earlier |
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Term
| Mechanisms of entrainment - lesion to optic nerves vs. optic tracts |
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Definition
| Optic nerve lesions abolish ability to entrain, but optic tract lesions do not |
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Term
| What tracts are required for light entrainment of circadian cycles to occur? |
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Definition
| Retinohypothalamic tracts |
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Term
| What retinal cells are needed for entrainment |
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Definition
Need specialized retinal ganglion cells w/ melanopsin pigment to transmit info through retinohypothalamic tracts
DO NOT NEED rods or cones |
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Term
| First mammalian circadian gene identified? |
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Definition
TAU
Tau mutants have irregularly short free running cycles (only 20 hrs) |
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Term
| What happens to sleep patterns in cerveau isole vs. encephale isole preparations? |
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Definition
Cerveau isole - have almost continuous SWS
Encephale isole - have normal sleep-wake EEG readings |
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Term
| Where are the transections in cerveau isole vs. encephale isole preparations? |
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Definition
Cerveau isole = midcollicular (in between superior & inferior colliculi)
Encephale isole = at level of caudal brainstem (just above SC) |
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Term
| Function of the posterior vs. anterior hypothalamus in sleep? |
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Definition
POSTERIOR - promotes WAKEFULNESS
ANTERIOR - promotes SLEEP |
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Term
| Experiments with cerveau & encephale preparations showed the involvement of the __________ with sleep |
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Definition
| RETICULAR FORMATION (located between colliculi & caudal brainstem) |
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Term
| Lesions to the reticular formation cause... |
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Definition
| Continuous slow wave sleep (just like cerveau isole preparation) |
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Term
| High vs. low reticular formation activity produces? |
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Definition
HIGH = WAKEFULNESS
LOW = SLEEP |
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Term
| Where are REM sleep nuclei located? |
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Definition
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Term
| What effects to benzodiazepines have on the stages of sleep? |
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Definition
| Increase length of stage 2 sleep (spindles & K complexes) and decrease length of stage 4 and REM sleep |
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Term
| Worst side effect of taking benzodiazepines as hypnotics? |
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Definition
| Can substantially reduce life expectancy |
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Term
| Synthesis of melatonin is ____________ by light and ___________ by dark |
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Definition
Synthesis INHIBITED by light
Synthesis STIMULATED by dark |
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Term
| The SCN regulates melatonin synthesis from _________ |
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Definition
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Term
| Melatonin is best considered to be a __________ agent |
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Definition
| Chronobiotic (chrono-biologic agent) - helps reset biological clock |
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Term
| How does consumption of nutrient dense, calorie poor foods increase lifespan? |
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Definition
Believed to increase melatonin synthesis
Producing more melatonin in older mice prolonged survival |
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Term
| Which PD drug can be used to treat restless leg syndrome? |
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Definition
| L-dopa -> may have DA deficiency in restless leg syndrome |
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Term
| Post mortem studies of individuals with restless leg syndrome show.... |
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Definition
| Selective Fe deficiency in substantia nigra cells; abnormally low levels of Fe storage proteins & Fe transporters |
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Term
| Differences between periodic limb movement disorder & restless leg syndrome? |
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Definition
PLM disorder = involuntary, only during sleep
RL syndrome = voluntary; happens when awake b/c movements are made consciously |
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Term
| Most common cause for insomnia in humans.... |
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Definition
| Sleep apnea (20 to 30 sec episodes of breathing cessation happening 20-30x per hour) |
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Term
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Definition
| 5-HTP is a serotonin precursor that can cross the BBB; good for serotonergic antagonist induced insomnia in cats, but no real effect in humans doe |
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Term
| Sleep promoting effect of melatonin is a _____________ effect |
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Definition
| SOPORIFIC (sleep promoting) effect |
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Term
| One of the most effective therapies for insomnia is... |
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Definition
| Sleep Restriction Therapy - reduce amount of time spent in bed; then gradually increase it as long as sleep latency remains normal |
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Term
| Differences in cause of sleep apnea |
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Definition
OBSTRUCTIVE - increased risk with increased size of adenoids, obesity, bone & muscle structure in neck; at least 95% of cases
CENTRAL - CNS doesn't send correct signals to breathing muscles; may be the cause of death in SIDS |
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Term
| 2 main symptoms of narcolepsy |
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Definition
Severe daytime sleepiness w/ inappropriate daytime sleep episodes
Cataplexy - recurrent loss of muscle tone during wakefulness |
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Term
| ______ = recurrent loss of muscle tone during wakefulness |
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Definition
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Term
| How much more per day do narcoleptics sleep on average? |
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Definition
| ONLY about 1 hr more, but sleep is inappropriate! |
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Term
| A _______ latency to sleep and REM sleep is seen in narcolepsy |
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Definition
| DECREASED latency for both normal sleep and entering REM sleep |
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Term
| Believe narcolepsy is triggered by abnormalities in ______ |
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Definition
| REM sleep triggering mechanisms - lack of latency before REM sleep, enter it right away (explains cataplexy, hypnagogy & sleep paralysis) |
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Term
| Orexin production is linked to the __________ hypothalamus |
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Definition
| POSTERIOR (promotes wakefulness) |
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Term
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Definition
| Structure in caudal RF that controls muscle relaxation during REM sleep |
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Term
| Most cases of human narcolepsy are.... |
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Definition
NOT caused by a defective gene
Do see selective loss of orexin producing cells in hypothalamus though (may be autoimmune)
ONLY IN narcolepsy w/ cataplexy |
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Term
| In narcolpetics w/ cataplexy, the # of glial cells is.... |
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Definition
| INCREASED - see increased gliosis in posterior hypothalamus where orexin neurons are lost (consistent with degenerative cause of cell loss) |
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Term
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Definition
Amphetamine like drugs - treat sleepiness
Antidepressants - treat abnormal awake time REM symptoms (hypnagogy, sleep paralysis) |
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