Question

nAChRs are permeable to Na+ and K+ and sometimes Ca²+ and therefore cause EPSPs, correct me if I'm wrong!

But then which (ACh) receptors would cause IPSPs? Are those caused by mAChRs?

Answer 1

@aaronq perhaps? :P

Answer 2

@thomaster?

Answer 3

nAChRs do allow the influx of Na+ when activated, so they change the potential across the membrane which leads to excitatory postsynaptic potentials. K+ efflux allows for hyperpolarization of the membrane. Ca2+ is needed for vesicle exocytosis.

yes, inhibitory signals would come from inhibitory G-protein coupled receptor subunits.

Answer 4

the re are two different subtypes of ACh receptors: nicotinic and muscarinic.

Nicotinic receptors enclose membrane channels and open when ACh bonds to the receptor. This causes a depolarization called an excitatory postsynaptic potential (EPSP) in skeletal muscle cells.
The binding of ACh to muscarinic receptors opens ion channels indirectly, through the action of G-proteins. This can cause a hyperpolarization called an inhibitory postsynaptic potential (IPSP).