Give a brief account of : Mechanism of synaptic transmission
Synaptic transmission can be of two types : (i) Transmission of nerve impulse through electrical synapse. (ii) Transmission of nerve impulse through chemical synapse. Electrical synaptic transmission: At electrical synapses, the membranes of pre- and post- synaptic neurons are in very close proximity. Electrical current can flow directly from one neuron into the.other across these synapses. Transmission of an impulse is very similar to impulse conduction along a single axon. Chemical synaptic transmission : The membranes of the pre- and post-synaptic neurons are separated by a fluid-filled space called synaptic cleft. Neurotransmitters are involved in the transmission of impulses. When an impulse (action potential) arrives at the axon terminal, it stimulates the movement of the synaptic vesicles towards the membrane where they fuse with the plasma membrane and release their neurotransmitters in the synaptic cleft.The released neurotransmitters bind to their specific receptors, present on the post-synaptic membrane. This binding opens ion-channels allowing the entry of ions which can generate a new potential in the post-synaptic neuron.
