BioPsych Exam 2 Flashcards
Suprachiasmatic Nucleus
“Biological clock”
located in hypothalamus
Chronotype
shift of circadian rhythm
young- night owls
old- early bird
Process-S
sleep drive
impacted by level of activity and outside factors
mental labor causes a stronger sleep drive than physical labor
Process-C
wake drive
Restorative Theory
repair and regenerate body
muscle repair, tissue growth, increased protein synthesis, growth hormone release
neuroplasticity increases while sleeping
Elimination Theory
gets rid of excess sensory info
synaptic pruning and strengthening
Brain Plasticity Theory
Neural reorganization, growth of neurons and brain structures
Immobilization Theory
Sleep is innate response with species-specific patterns
keeps on inactive and safe during least efficient part of day/night cycle
Energy Conservation Theory
following survival activities
energy expenditure decreases when sleeping
10% decrease in metabolic rate
fatal familial insomnia
prions destroy neurons in thalamus
genetic mutation: first lose ability to have SWS, then REM, then unable to fall asleep, die within 6 months
Lack of SWS correlates with…
greater risk for cardiovascular disease, diabetes, obesity
Functions of REM sleep
promote brain growth
facilitate learning
consolidation of nondeclarative memory
REM rebound phenomenon
- if you pull an all-nighter you will make up REM sleep first, then SWS rebound
less REM sleep under influence
Electroencephalogram
(EEG)
electrical potential recorded from electrodes placed on scalp (“brain waves”)
detects neural activity/firing
Electrooculogram
EOG
measure of eye movements seen during sleep, detects muscle firing
SWS: slow rolling eye movements
REM: fast, left to right
Electromyogram
EMG
electrical potential recorded from an electrode placed on muscle (ex. arm or thigh)
measures changed in muscle tension/activity particularly in face and neck muscles
NO MUSCLE TONE DURING REM SLEEP
Mentalis muscle loses all tone as soon as you fall asleep, distinguishes sleep vs. wakefulness
Passive Theory of Sleep
proposed sleep is passive because it cuts off sensory input during surgery
-Cerveau isole
-separated forebrain from hindbrain
-cats did not wake up on their own
Encephale isole
- separated brain from spinal cord
- cats had normal sleep/wake cycles
Active Theory of sleep
- discovered Reticular Formation
- proposed sleep is inactive and the brain actively regulates sleep-wake cycle
stage 1 sleep
transition from wake-sleep (1-7 minutes)
stage 2 sleep
about 70-75% of nights sleep
- can last 10-25 minutes
- REM gets longer as night goes on
- spend more time dreaming towards morning
stage 3 sleep
- SWS
- long waves on EEG
- about 20-40 minutes
- harder to wake up from
- gets shorter towards morning
Gamma waves
- small and close together
- irregular, low amp
- highest frequency is about 30-120 Hz
- occurs at hyperfocus, concentration
Beta waves
- medium size
- irregular, low amp, highest frequency about 13-30 Hz
- occur during the day
Alpha waves
- big and far apart
- fairly regular, low amp, high frequency about 8-13 Hz
- occur during relaxation
Theta waves
- low amp, moderate frequency about 4-8 Hz
- occur during stage 2 sleep
Sleep Spindles
- short burst of about 12-14 Hz
- in between theta waves
- slow progression as we age (kids sleep better)
K complexes
sudden sharp waveforms
Delta waves
- fairly regular, high amp, low frequency about 1-4 Hz
REM sleep (paradoxical sleep)
a wave of beta and a wave of alpha
- (sleep and wake waves)
Acetylcholine (cholinergic neuron)
- dorsal pons and basal forebrain
- plays role in arousal of cerebral cortex
- levels high during wakefulness and REM sleep
- project to and impact medial pons, thalamus and cortex
- involved in cortex and hippocampus arousal
Norepinephrine (noradrenergic neuron)
- plays role in attention and vigilance
- levels high only during wakefulness
- project to impact thalamus, hippocampus, cerebellum, pons and medulla
Serotonin (serotonergic neuron) (5-HT)
- levels high during wakefulness
- levels fall as descending towards REM sleep
- cortical and behavioral arousal
- plays role in activating behavior (pacing, chewing, grooming in rodents)
- project to impact thalamus, hypothalamus, cortex, hippocampus, basal ganglion
Histamine
- levels high during wakefulness
- levels low during SWS and REM sleep
- implicated in control of wakefulness and arousal
- project to and impact cortex, thalamus, hypothalamus, basal ganglia, basal forebrain
Orexin
- from lateral hypothalamus
- levels high during wakefulness
- levels low during rest and all sleep stages
- increase activity in the brainstem and forebrain arousal systems
vIPOA
Ventrolateral preoptic area
vIPAG
ventrolateral periaqueductal area
SLD
sublaterodorsal nucleus
GABA
- from vIPOA
- suppress alertness and behavioral arousal
- promote sleep
Adenosine
Peptide released by neurons during high levels of metabolic activity throughout the day
- increases activity on the vIPOA
Cataplexy
muscle weakness while a person is awake
- can be caused by high emotion
sleep paralysis
loss of muscle tone as we fall asleep or wake up
- SLD activation before falling asleep
- SLD deactivation after waking up
2 types of Hallucinations
- hypnagogic
- hypnopompic
Hypnagogic
- SLD nucleus is starting to activate
- people will see “ghosts” or people who arent there
Hypnopompic
-delay between REM turning off
- SLD is still firing, causes dream to continue as people open their eyes
Narcolepsy
- difficulty staying awake during the day
- difficulty staying asleep during the night
- “skip” SWS and enter REM quickly
causes of narcolepsy
- deficiency of peptide neurotransmitter orexin
- in canines, Orexin B receptor
- in humans, complete absence of Orexin
Treatment of Narcolepsy
Ritalin: dopamine and norepinephrine agonist (Reuptake inhibitor)
Amphetamine: dopamine and norepinephrine agonist (reuptake inhibitor)
Modafinil (Provigil): orexin agonist (reduces daytime sleepiness
SSRIs and SNRIs
Fluoxetine
Venlafaxine
Atomoxetine
- reduce episodes of REM sleep components
Tricyclic antidepressants
norepinephrine, serotonin, dopamine agonist
Protriptyline (vivactil)
Imipramine (tofranil)
- reduce episodes of REM sleep components
Sodium Oxybate (Xyrem)
- CNS depressant that reduces excessive daytime sleepiness and cataplexy
- GABA-B receptor agonist (increases GABA)
- reduces daytime sleepiness, stay asleep through the night
Swyer Syndrome
46 XY genotype
15-20% SRY gene
- Appears as female but is missing the SRY gene on Y chromie
- non-functioning ovaries
- doesn’t start period
- take supplemental estrogen
46 XX Testicular Disorder
SRY gene is misplaces onto X chromosome
- development of male genitalia
- smaller testes and infertility may occur
Differentiation occurs at…
2nd and 3rd prenatal months
wolffian system
(male duct)
- prostate
- seminal vesicle
- male duct
- gonad
Mullerian System
(female duct)
- vagina
- Uterus
- Female duct (fallopian tube)
- Gonad
As testis develop…
- Mullerian-inhibiting substance (MIS) and testosterone are synthesized and released
- 5-alpha converts testosterone into dihydrotestosterone
must have dihydrotestosterone to…
develop a penis and scrotum
5-alpha-reductase deficiency syndrome
lack of 5-alpha- reductase
- born looking female, grow up looking male
female brains have…
- higher percentage of gray matter
- larger hippocampus
- larger ventral prefrontal cortex
- high levels of serotonin, dopamine, GABA
Male brains have…
- 10% larger cerebral hemispheres
- higher percentage of white matter and cerebral spinal fluid
- larger and more reactive amygdala
- larger hypothalamus
aromatase
converts testosterone into estradiol
alpha fetoprotein
- produced by fetal liver cells and placenta during fetal development
- binds circulating estradiol and prevents its entry into brain
- does not bind to testosterone
Hypothalamic-pituitary-gonadal axis
Paraventricular nucleus and supraoptic nucleus directly release hormones through posterior pituitary portal
- such as oxytocin
Anterior pituitary
releases gonadotropins
- Follicle-stimulating hormone
- luteinizing hormone
FSH
- ova development
- sperm development
- increase estradiol production
LH
- stimulates testosterone secretion
- from Leydig cells in testes
- from Theca cells in ovaries
- LH surge triggers ovulation
Gonadal hormones
- androgens
- estrogens
- gestagens
Androgens
ex. Testosterone
- Leydig cells in testes
- Theca cells in ovaries
androgens are responsible for…
- growth and repair of reproductive cells
- Development of bone mass
- Development of hair in puberty in females
- Development of hair in males (facial, body)
- Maturation of sperm
- Secondary sex characteristics in males during puberty
Estrogens
ex. estradiol
- converted from testosterone by aromatase
estrogens are responsible for…
- Thickening uterine wall
- Maturation of eggs
- Sex drive
- Erections in males
Gestagens
ex. progesterone
- important role in female fertility and reproduction
Gestagens are responsible for…
Thinking of uterine lining
“Pregnancy hormone”
High during pregnancy
Low levels can cause a miscarriage
Prohibits contraction of uterus during labor
Maybe involved in the creation of sperm?
combination pill
delivers both estrogen and progestin for 3 weeks
how does the combination pill work?
Estrogen decreases secretion of FSH
- Estrogen starts on day 1 of cycle, given for about 3 weeks, then interferes with FSH
FSH is being reduced, no additional estradiol from ovaries, comes from the pill instead
- Reduction of pulsing from hypothalamus
Progestin prevents secretion of LH
Plan B
- stops the release of ovum
- Prevents ovulation from occurring when sperm is still viable
24 hours, 95% effective
24-72 hours, 89% effective
Mifepristone
- progesterone receptor blocker
- stop pregnancy from continuing
— uterine wall deteriorates
— placenta detaches - used to end early pregnancy (within 70 days or less since last menstrual period
- followed by Misopristol
— causes uterine contractions
— softens and dilates cervix
Medial Preoptic Area (MPA of hypothalamus) (males)
- Involved in regulation of male sexual behavior in rodents
- Drives behaviors, impacted by testosterone
— erections
— Mounting of female
— Thrusting/ejaculation - Damaged can cause behaviors to not occur
Lee-Boot effect
- Groups and colonies that are matriarchal
- without presence of males , cycles sync and stop
- If male becomes present within 48 hours, go into estrice
Whitten effect
- Group of females housed together, estrice cycles sync and go into estrice at same time, synced cycles
Bruce effect
- Colony of females with one dominant male
- When a new male takes over, any females that are starting pregnancy with prior male, the eggs will not plant
- Pheromones from new male can cause miscarriage
Vandenbergh effect
- Matriarchal clones, introduction of male accelerates sexual maturity in young female (accelerates puberty)
Ventromedial nucleus (VMN of hypothalamus) (females)
- regulation of female sexual behavior in rodents
- stimulate arousal
Lordosis posture
(throwing it back)
- driven by higher levels of estradiol being released during estrice
- more estradiol, more activation of VMN
ingestion
- pills
- easy to administer
- relatively safe
- takes time for medication to break down, allows time for intervention in case of side effect
downsides of ingestion
- unpredictability of dosing (“must be taken with food”)
- some drugs can be deactivated as soon as they hit the stomach
subcutaneous injection
- injection in fatty layer between skin and muscle
ex. insulin
intramuscularly (IM) injection
injected in large muscles
ex. vaccines
intravenous (IV) injection
injected directly into bloodstream
- strongest, fastest, and most predictable
downsides of intravenous injection
- risk of overdose
- use of same needle can lead to infection
- only so many places to inject
— people who abuse injection develop scar tissue or collapsed veins
Inhalation
- directed into bloodstream through the lungs
ex. nicotine, THC, asthma meds - lower dosage than ingestion and injection
downsides of inhalation
- depends how strongly they inhale
- has to be a particular dose
- lung damage
Absorption
- through lining of nose or mouth
ex. chewing tobacco, nicotine pouches, snorting cocaine - quicker than ingestion
downsides of absorption
- relies on tissue you place substance in
- repeated use, tissue becomes scarred and not as effective
- causes deterioration or ulceration
tolerance
less reactivity to substance
Functional tolerance
- response to drug is decreased by cellular mechanisms
ex. receptor changes
Metabolic tolerance
- decrease in amount of drug that reaches the target site
- the more repetition of drug use, the body changes to get rid or deactivate it faster
conditioned tolerance
environmental cues activate a compensatory response that counteract the drug effect
ex. alcohol causes a decrease in body temp, can cause hypothermia
Intracranial Self-Stimulation (ICSS)
rat presses lever themself
- implanted electrode on hypothalamus, continue to press the lever for stimulation
Conditioned place preference
- rats hang out in chamber if they liked the drug
- avoids chamber if they didn’t like it
Positive Reinforcement
- drug-taking behavior is followed by a pleasant outcome of the drug
- seek out drug again
Negative reinforcement
- drug-taking behavior is followed by the removal of an unpleasant event
- feel relief; seek out drug again
Physical dependence theory of addiction
physical changes start to show, so they take the drug for withdrawal symptoms to go away
- negative reinforcement
Positive Incentive Theory of addiction
the drug makes you feel good so that’s why you take it
- positive reinforcement
Incentive Sensitization theory of addiction
after tolerance develops, changes the craving for the drug, remembers how it used to make them feel good so they keep taking it
- positive reinforcement
What are the 3 pathways in the Mesotelencephalic Dopamine System
- nigrostriatal pathway
- mesolimbic pathway
- mesocortical pathway
Nigrostriatal pathway
- starts in substantianigra, ends in dorsal striatum
— deteriorates early in parkinson’s disease
Mesolimbic pathway
- ventral tegmental area
— stimulating dopamine release has an effect on emotional experience
— (rewarding effects)
Mesocortical pathway
- ventral tegmental area to prefrontal cortex
— remembering how the drug made you feel (incentive sensitization theory)
mapping studies
indicate that areas that support ICSS are typcally part of the mesotelencephalic dopamine system
Lesion studies
show that 6-hydroxydopamine chemical lesions disrupts ICSS
— (destroys dopamine)
Antagonist studies
show that dopamine antagonists decrease ICSS
— once you stop dopamine receptors, rats stop pressing lever
Agonist studies
show that dopamine agonists increase ICSS
