The Synapse

The cells of your nervous system are constantly receiving and transmitting information, from basic bodily function to sensory stimulus. Neurons communicate with electrical signals called action potentials. These action potentials originate in the cell body and travel along the axon to the axon terminal where they are passed on to the next cell.

The point at which two neurons meet is called the synapse. Electrical synapses allow direct communication between cells using gap junctions, and are often involved in coordination of rapid activity. However, most synapses are chemical synapses that contain a synaptic cleft, the physical space that exists between the neuron sending the signal, known as the presynaptic cell, and the neuron receiving it, called the postsynaptic cell.

Action potentials cannot travel across the synaptic cleft, so neurons convert the electrical signal into a chemical signal at the synapse. This is accomplished by the release of molecules known as neurotransmitters. There are many neurotransmitters, each with different effects on the postsynaptic neurons, including the excitatory glutamate and the inhibitory GABA, among others.

When the action potential reaches the