Q. The release of chemical messenger from synaptic vesicles is under the influence of these ion(s).

 1870  212 AIIMSAIIMS 2012Neural Control and Coordination Report Error

Solution:

When an impulse arrives at the synaptic knob of the axon, it depolarizes the presynaptic membrane and increases its permeability to calcium ions (Ca2+). Ca2+ ions from the synaptic cleft pass into the synaptic knob via voltagegated channels. Sudden rise in the cytosolic concentration of Ca2+, causes the release of a chemical, called neurotransmitter substance, from small synaptic vesicles present there into the synaptic cleft by exocytosis through the presynaptic membrane.