Structure of the Synapse

(Modified from Pierre S, Eschenhagen T, Geisslinger G, et al. Capturing adenylyl cyclases as potential drug targets. Nat Rev Drug Discov. 2009;8:321-335.)

Axons typically have many synapses, not just the single synapse implied by the conventional typical rendition below. The presynaptic membrane encloses the synaptic vesicles that contain the neurotransmitters, the reuptake pump that removes the neurotransmitter following synaptic transmission, and the voltage-gated calcium channel that responds to the incoming action potential. The ligand-gated receptors in the postsynaptic membrane trigger an efferent action potential. The postsynaptic density contains multiple proteins and receptors and appears responsible for organizing the structure of the receptors on the synapse.