Basic Biology Flashcards
SSRI mechanism
Downregulation - chronic activation of 5HT1A auto receptors causes down regulation which leads to degradation and genetic changes -reduction- in producing new Receptors, therefore serotonin is sensed less and more serotonin stays around.
Tardive dyskinesia mechanism
Chronic antagonism of dopamine receptors increases the receptor load, making us more sensitive to dopamine, and therefore movement disorders result that are hyperkinetic like tics or courier
How do anticholinergic affect tardive dyskinesia
Anticholinergic make it worse because they decrease a CH and increase dopamine
EPS mechanism
EPS results at the beginning of antipsychotic treatment because of too little dopamine anticholinergic help this because they increase dopamine and decrease ACH
Fast ion channel Neuro transmitter examples
NMDA GABA glutamate
Slow GCPR NRT examples
Monoamine: NE, DA, 5HT
Allosteric site
a SIDE SITE that Some substance other than the primary NRT binds at to make the receptor do it’s normal function
Inverse agonist
Stops even the baseline flux of a receptor. Stronger than antagonist which just stops the extra opening.
Agonist and partial agonist are intuitive.
Serotonin
Tryptophan > tryptamine > 5HT
5HT nucleus
Raphe nucleus
Basal ganglia 5ht2a/c
Repetitive movements / ocd
Serotonin in the limbic area
Anxiety / panic
Serotonin in the hypothalamus
Regulates appetite and eating behavior
5HT1A
GPCR DENDRITIC Auto receptors that regulate decrease five HTP release
Neurogenesis and arborization
5HT 1B and 1D
Nerve terminal auto receptors
1D causing vasoconstriction helpful in migraines (ergot)
Chronic SSRIs downregulate ** receptors. Leads to better 5HT/receptor ratio
(serotonin deficit hypothesis)
5HT2
5HT2A mechanisms [5: BG, MC, SWS, O, A]
Projects to BG to control movement/compulsions.
Mesocortical reduces DA»_space; causing apathy and diminished libido.
Regulates slow-wave sleep.
Stimulation inhibits orgasm/ejaculation.
2A and 2C projection to limbic decreases panic/anxiety
5HT2C
Anxiety with 2A and
weight gain (sep from Histamine)
5HT receptors are all ** type*
GPCR except 5HT3 (ion)
5HT3 facts (2: GI and AE)
GI effects of SSRIs are due to activation of this receptor system.
**Anti-emetics antagonize 5HT-3 (ondansetron).
Projections to hypothalamus may regulate appetite and eating behavior (satiety)
DA creation
L-tyrosine > L dopa > DA >VMAT> vesicles > Reuptake via DAT
*Bupropion and sertraline -| DAT
Amphetamine on DA
Reverse the Na/K pump that aids in DA reuptake
Mesolimbic DA
ventral tegmental > hypothalamus > limbic, frontal and nucleus accumbens.
Reward behavior and addiction
POSITIVE SX (too much)
Mesocortical DA
hypothalamus > Limbic and cortex
Cognition Motivation
NEGATIVE sx (too little DA)
