Exam 3 Flashcards
serotonin is synthesized from what
tryptophan
two steps to serotonin synthesis
catalyzed by TPH and AADC
TPH2
in serotonergic neurons
how is serotonin synthesis regulated
enzymatic activity and precursor activity
why does tryptophan compete with amino acids
to cross the blood brain barrier and increase serotonin
what diet increases ratio of tryptophan
low protein high carbohydrate
what does elevating tryptophan do
enhance cognitive functions (memory, attention), elevate mood, improve sleep
tryptophan loading
administration of pure tryptophan
if you inhibit TPH you get
less serotonin
reducing serotonin via ATD method does what
impairs memory consolidation of verbal information but has no influence on working memory and attention
serotonin is transported into synaptic vesicles by
VMAT2
reserpine does what
depletes serotonin (broken down when not in vesicles)
terminal autoreceptors do what to serotonin
directly inhibit release
somato-dendritic autoreceptros do what to serotonin
inhibit release by slowing rate of nerve firing
what reuptakes serotonin
SERT
antidepressant drugs
SSRI’s
how do SSRIs work
by blocking the serotonin transporter
where are serotonergic neurons found
along the midline of the brainstem (raphe nuclei)
what are the roles of dorsal raphe nucleus (DRN) and median raphe nucleus (MRN)
give rise to most of the serotonergic fibers in forebrain
when awake, how do serotonin cells fire
a regular rate (tonic firing)
how do serotonin cells fire when in slow wave sleep
irregularly
slow tonic firing of DRN neurons promotes what
non REM sleep
burst firing of DRN neurons promotes what
wakefulness
where is serotonin 1a receptor concentrated
in hippocampus, septal area, and DRN
what does the serotonin 1A receptor do
inhibit adenylyl cyclase to decrease cAMP, increase opening of K+ channels and membrane hyperpolarization
what kind of receptor is serotonin 1A
autoreceptor and postsynaptic
where are serotonin 2A receptors located
cortex
what do serotonin 2a receptors do
increase Ca2+ levels in postsynaptic cell and activate protein kinase C
what kind of receptor is serotonin receptor 2A
activating
most serotonergic neurons in the CNS are located
raphe nuclei
serotonin has a key role in regulation of
anxiety through postsynaptic serotonin 1A receptors
serotonin deficiency hypothesis
low CNS serotonergic activity is associated with hyper aggressiveness
what is a behavior/function influenced by serotonin
anxiety, appetite, and sleep
what does MDMA do
stimulates release of serotonin from nerve terminals and inhibits reuptake
effects of MDMA
heightened arousal, euphoria, enhanced perceptual awareness, prosocial effects
high MDMA doses result in
serotonin depletion (in animals)
designer drugs
synthetic cathinone and amphetamine variants
synthetic cathinones
are substrates for dopamine, norepinphrine, and serotonin transporters, and cause acute release of dopamine, serotonin, and norepinephrine
what kind of drugs are opioids
narcotic analgesics (reduce pain without producing uncosciousness)
psychoactive ingredients in opiates
morphine and codeine
partial agonists
less analgesic effect, reduced risk of dependence
antagonist
can prevent or reverse effects of opioids (treatment for overdose)
which reaches the brain faster: heroin or morphine
heroin
adverse affects of opoids
restlessness, anxiety, nausea/vomiting
higher doses of opiods
abnormal state of elation or euphoria