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NEUROPHYSIOLOCY

Synaptic Transmission: Morphology of Synapses

Numęrous boutons (synaptic knobs) of presynaptic neurons terminating on a motoi neuron and its dendrites

Figurę 2.4 Morphology of Synapses_

Neurons communicate wdlh each other and wilh effector targets at specialized regions called synapses. The top hgure shows a typical motor neuron that receives numerous synaptic contacts on its celi body and associated dendrites. Incoming axons lose thoir myelin sheaths, exhibii extensive branching, and terminale as synaptic bou-tons (synaptic tcrminals Or knobs) on tire motor neuron. The lowcr figurę shows an enlargement of one such synaptic bouton. Chemical neurotransmiłlers are contained in synaptic vesides, which can fuse with the presynaptic membranę, release the transmitters into the Synaptic cJeft. and then bind to receptors siluated in the postsynaptic membranę. This synaptic transmission results in excitatory, inhibitory, or modulatory effects on the target celi.

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