FIGURE 5-2 Chemical Synapse (A) Surrounding the central synapse in this electron micrograph are glial cells, axons, dendrites, other synapses, and a synaptic cleft. (B) Within a chemical synapse, storage granules hold vesicles containing neurotransmitter that travel to the presynaptic membrane in preparation for release. Neurotransmitter is expelled into the synaptic cleft by exocytosis, crosses the cleft, and binds to receptor proteins on the postsynaptic membrane.

Joseph F. Gennaro Jr./Science Source, Colorization by: Mary Martin