introduction to neuropharma Flashcards
how do all CNS neurotransmitters act, what is difference between LGIC mediated action and GPCR mediated action
all transmitters are agonists of either excitatory or inhibitory receptors
LGICs mediate fast effects and cause neurotransmission
GPCRs mediate 2nd messenger responses which are slow, cause neuromodulation
how does activity of presynaptic and post synaptic receptors differ
presynaptic receptors modulate NT release
post synaptic receptors alter activity
which NTs are always excitatory
glutamate (some metabotropic receptors are inhibitory) and aspartate
which NTs are always inhibitory
GABA
what glutamate receptors are there, what type of receptors are they
AMPA: LGIC
NMDA: LGIC
kainaite receptor: LGIC (delayed action)
metabotropic GluRs: GPCRs
describe the AMPA receptor, including agonists and antagonists
LGIC for sodium
agonists: AMPA and glutamate
antagonists: NBQX
describe NMDA receptor, including agonists and antagonists
NMDA receptor: LGIC for sodium and calcium
normally blocked by magnesium, this is removed when membrane is depolarised, causing NMDA receptor to be voltage gated
agonists: NMDA and glutmate, glycine is a co-agonist
antagonists: ketamine, MK-801
what are the GABA receptors, describe them
GABAa-c
GABAa: LGIC for chloride
GABAb: GPCR associated potassium/chloride channel
what are agonists/antagonists of GABAa and GABAb receptors
agonists:
GABAa: GABA, muscimol
(benzos and barbiturates potentiate GABAa channels)
GABAb: GABA, baclofen
antagonists:
GABAa: bicuculline
GABAb: CGP35358
how does Ach work in the CNS
on nicotinic receptors: excitatory LGIC
on metabotropic receptors: M1,3 and 5 are excitatory, M2 and 4 are inhibitory
effects of Ach can be excitatory (nicotinic, M1,3,5) or inhibitory (M2,4)
nicotonic receptors have neuronal and muscular variants which have separate antagonists
which transmitters are monoamines
5HT, noradrenaline, dopamine
describe dopamine receptors
receptors: D1-5, all GPCRs
D1 and 5 are excitatory
D2-4 are inhibitory
agonists: dopamine and bromocriptine
amphetamines indirectly activate D receptors since they cause release of dopamine
antagonists: haloperidol
describe 5HT receptors
receptors: 5HT1-7, all GPCRs
5HT1: inhibitory
5HT2: excitatory
how do peptide transmitters differ from others
they only excite or inhibit, never both
important in long term changes in activity
all peptide receptors are GPCRs
give examples of peptide transmitters
opioids, gastrins, tachykinins and NPYs
