Give a brief account of: Mechanism of synaptic transmission
(a) Synapse is a junction between two neurons. It is present between the axon terminal of one neuron and the dendrite of next neuron separated by a cleft. There are two ways of synaptic transmission. (1) Chemical transmission (2) Electrical transmission 1. Chemical transmission: When a nerve impulse reaches the end plate of the axon, it releases a neurotransmitter (acetylcholine) across the synaptic cleft. This chemical is synthesized in the cell body of the neuron and is transported to the axon terminal. The acetylcholine diffuses across the cleft and binds to the receptors present on the membrane of next neuron. This causes depolarization of membrane and initiates an action potential. 2. Electrical transmission: In this type of transmission, an electric current is formed in the neuron. This electric current generates an action potential and leads to transmission of a nerve impulse across the nerve fibre. This represents a faster method of nerve conduction than the chemical method of transmission.
