What is the mechanism of nerve impulse transmission at the synapse?
1 Answer
Synapse or neuronal junction is the site of transmission of nerve impulse between two neurons.
Explanation:
The synapse along with its neurotransmitters acts as a physiological valve, directing the conduction of nerve impulses in regular circuits and preventing random and chaotic stimulation of nerves.
The arrival of the nerve impulse at the presynaptic terminal, causes a movement towards the synaptic vesicles. These fuse with the membranes and release neurotransmitters.
A single neurotransmitter may elicit different responses from different receptors.
The neurotransmitter transmits the nerve impulse to the post synaptic fibre, by diffusing across the synaptic cleft and binding to receptors on the post synaptic membranes.
This results in a series of reactions that open ' channel shaped ' protein molecules. Electrically charged ions then flow through the channels, in or out of the neurons.
If the net flow of positively charged ions is large enough, it leads to the generation of a new nerve of impulse, called action potential.
Later the neurotransmitter molecules are deactivated by enzymes in the synaptic cleft.
