Acetylcholine plays a multifaceted role in both the CNS and PNS. In the CNS, it is involved in cognitive functions like learning and memory. In the PNS, acetylcholine is essential for muscle activation and various autonomic functions. It acts on two types of receptors: nicotinic receptors and muscarinic receptors. Nicotinic receptors are ionotropic and mediate fast synaptic transmission, whereas muscarinic receptors are metabotropic and mediate slower, prolonged responses.
