NTs 2 Flashcards
DA receptors: structure? two groups and how they work?
all heptahelical, no ionotropic. D1 like = D1 and D5 couple to Gq and Gs. D2 (D2, 3, 4) couple to Gi
D2 receptors function
major autoreceptor, but can also be found postsynpatically
D2 antagonists used for
antiemetic agents, act in chemoreceptor trigger zone in area postrema
D2 autoreceptor activation can alter transmission in 3 ways
suppress presynaptic Ca channel current. hyperpolarize presynpatic terminals via activating GIRK channels. direct effects on release process.
correlation between D2 antagonist affinity and?
antipsychotic action. higher affinity = need lower dose for antipsych effect
3 dopamine systems
nigrostriatal. tuberoinfundibular. mesolimbic.
nigrostriatal: main idea + what areas
parkinson’s: substantia nigra pars compacta to caudate/putamen neostriatum
tuberoinfundibular: main idea + what areas
arcuate nucleus to pituitary: for prolactin
mesolimbic: main idea + what areas
for addiction and reward: ventral tegmental area, nucleus accumbens, cingulate and frontal cortex
nigrostriatal DA system is involved in? what disease and what drug?
control of mvt, learning of motor programs. loss of DA neurons in SN = Parkinson’s. L-DOPA to replace DA
tuberinfundibular system: function? effect of antipsychotic drugs?
hypothalamic arcuate nucleus cells project and inhibit release of PRL from pituitary. antipsych drugs increase PRL, produce hyperprolactinemia and lactation
bromocriptine: what and effect
D2 agonist. mimics DA. inhibits prolactin release so treats hyperprolactinemia
what DA receptors in nucleus accumbens? do what? role?
D1, D2, D3 receptors inhibit spiny projection neurons. involved in cognitive and emotive functions; reward and addiction
antipsychotic drugs and mesolimbic?
D2 antagonists = antipysch drugs. but possibility of PD like side effects
serotonin: receptors - types and general structure
metabotropic G protein coupled: 5HT1, 2, 4, 5 - 7. also have 5HT3 = cation channel
serotonin: cell bodies where? peripheral roles?
cell bodies in raphe nuclei. peripheral role in enteric NS
serotonin: how to terminate action? drug?
transporter/uptake system. SSRIs like fluoxetine / prozac to treat depression
serotonin syndrome: what three categories of effects
cognitive, autonomic and somatic
serotonin syndrome: cognitive effects
headache, migraine. mental confusion. hallucinations (like LSD which agonizes 5HT2). coma (5HT involved in sleep)
serotonin syndrome: autonomic effects
shivering, sweating, hyperthermia. hypertension. tachycardia. nausea, diarrhea (hyperkinetic effect on gut). mydriasis = pupil dilation
somatic effects from serotonin syndrome: 3
myoclonus = muscle twitching, hyper reflexia. tremor
nitric oxide: receptor? effect? 3 isoforms?
guanylyl cyclase - makes cGMP. neuronal, endothelial and inducible isoforms
functions of NO
vasodilation, nonadrergic noncholinergic intestinal relaxation, erection, neuro toxicity and plasticity, central autonomic functions
NO pathway of synthesis
endothelial cell: ACh/bradykinin, substance P activates receptors = increase in Ca. calmodulin activates NOS to produce NO + citruilline from arginine.