A nerve impulse is transmitted from one neuron to another through junctions called synapses. At a chemical synapse, the membranes of the pre – and post – synaptic neurons are separated by a fluid-filled space called Synaptic cleft. Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses. When an impulse 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 postsynaptic neuron. The new potential developed may be either excitatory or inhibitory.
