What is a synapse and what does it do?

Together with its neurotransmitters, the synapse functions as a physiological valve, preventing random and chaotic nerve stimulation and guiding the conduction of nerve impulses in regular circuits.

The movement towards the synaptic vesicles, which fuse with the membranes and release neurotransmitters, is triggered by the arrival of a nerve impulse at the presynaptic terminal. Different receptors may respond differently to a single neurotransmitter.

By diffusing across the synaptic cleft and attaching to receptor molecules on the post synaptic membrane, the neurotransmitter sends the nerve impulse to the post synaptic fiber.

Electrically charged ions then flow through the channels in or out of the neurons as a result of a series of reactions that open "channel shaped" protein molecules. If the net flow of positively charged ions is large enough, it results in the generation of a new nerve impulse known as an action potential.

Enzymes in the synaptic cleft later deactivate the neurotransmitter molecules.

An essential component of nervous system communication, a synapse is a structure that permits a neuron to transmit an electrical or chemical signal to another neuron or to the target effector cell.