CNS, synapse (EM, Medium)

Structure List Dendrite Axon terminals Synaptic vesicles Mitochondria Presynaptic membrane Postsynaptic membrane Synaptic cleft

Axons projecting from neurons terminate at swellings, called boutons, which join to the membrane of other neurons or of other cell types to be innervated or to form a synaptic junction. Using the diagram, identify on these three electron micrographs the most important aspects of axon synapse with a dendrite. These include the synaptic vesicles, which store the neurotransmitter, mitochondria to supply energy, the presynaptic membrane, the postsynaptic membrane and the synaptic cleft or space between these two membranes. Note that the pre- and postsynaptic membranes are much denser than the remainder of the cell membranes on the dendrites and the axons.