Answer
At some excitatory receptors, ACH binds to ionotropic receptors that have cation channels. The binding opens the cation channels, and the which move down their electrochemical gradients; the result is generation of an EPSP in the post synaptic cell. However, at some postsynaptic cells, the binding of ACH to metabotropic receptors will generate an IPSP instead of an EPSP.
Work Step by Step
The metabotropic receptor has a binding site for ACH plus a G protein which is coupled to an ion channel. The binding of ACH to the receptor activates the G protein which opens the cation(K+) channels. The efflux of K+ ions generates an IPSP.
