What is synapse?

The synapse is the structure that mediates the effects of a nerve impulse on a target cell, permitting communication among nerve cells, muscles and glands.  It is contact point where information is transferred. Usually, synapses are made between the axon of a presynaptic neuron, the sender and the dendrite of a postsynaptic neuron, the receiver.

There are two types of synapses electrical synapses and chemical synapses. Chemical synapses may act either directly through ion channels or indirectly through second messengers.

A single neuron can have up to approximately 10,000 synapses. Changes in the number and strength of synapses, called synaptic plasticity are thought to be biological mechanism of all learning and memory.

Defining the presynaptic specialization is a cluster of synaptic vesicles ( ~40 nm diameter) containing neurotransmitters, some of which are closely associated with a thickening of the presynaptic plasma membrane, called the active zone.

Messages arrive at the synapse in the form of action potentials. Synaptic potential are triggered by action potentials; they in turn trigger subsequent action potential, continuing the neural message on to its destination.
What is synapse?