Communication between cells
A synapse is a junction through which cells in the nervous system communicate. The signal reaching the junction is converted from an electrical nerve impulse into a chemical signal carried by a neurotransmitter.
- The presynaptic cell carries the nerve impulse towards the synapse.
- The synaptic cleft is the gap separating the two cells.
- The postsynaptic cell receives the signal and may be another neurone or an effector cell.
- Vesicles in the presynaptic cell contain neurotransmitter.
- The postsynaptic membrane contains receptors to which the neurotransmitter can bind.
During synaptic communication, neurotransmitter is released from the presynaptic cell, diffuses across the synaptic cleft and binds to receptors in the postsynaptic membrane.