An
electrical synapse is a mechanical and electrically
conductive link between two neighboring
neurons that is formed at a narrow gap between the pre- and postsynaptic neurons known as a
gap junction. At gap junctions, such cells approach within about 3.5 nm of each other, a much shorter distance than the 20- to 40-nanometer distance that separates cells at
chemical synapse. In many
animals, electrical synapse-based systems co-exist with
chemical synapses.