At the terminal end of the axon is a branched structure with ends called synaptic knobs. From this structure chemical signals can be sent to neighboring neurons. Transmission of nerve impulse along the axon
When an action potential reaches the axon terminal of a motor neuron, vesicles carrying neurotransmitters (mostly acetylcholine) are exocytosed and the contents are released into the neuromuscular junction.These neurotransmitters bind to receptors on the postsynaptic membrane and lead to its depolarization.he small depolarization associated with the release of acetylcholine from one synaptic vesicle is called a miniature end-plate potential (MEPP). MEPPs are additive and lead to a greater depolarization of the postsynaptic membrane and become end plate potentials (EPPs).
The area in the axon that holds groups of vesicles is an axon terminal or bouton. Up to 130 vesicles can be released per bouton over a ten-minute period of stimulation at 0.2 Hz. In the human brain region V1 synaptic vesicles have an average diameter of 39.5 nanometers with a standard deviation of 5.1 nanometers.ith the advent of modern electron microscopic techniques in the early 1950s, nerve endings were found to contain a large number of electron-lucent vesicles. The term synaptic vesicle was first introduced by De Robertis and Bennett in 1954.