Chemical synapse cells, known as a gap junction. At gap junctions, cells approach within about 3.5 nm of each other, rather than the 20 to 40 nm distance that separates cells at chemical synapses. As opposed to chemical synapses, the postsynaptic potential in electrical synapses is not caused by the opening of ion channels by chemical transmitters, but rather by direct electrical coupling between both neurons. Electrical synapses are faster than chemical synapses. Electrical synapses are found throughout the nervous system, including in the retina, the reticular nucleus of the thalamus, the neocortex, and in the hippocampus. While chemical synapses are found
Action potential potential. Their joint efforts can be thwarted, however, by the counteracting inhibitory postsynaptic potentials. Neurotransmission can also occur through electrical synapses. Due to the direct connection between excitable cells in the form of gap junctions, an action potential can be transmitted directly from one cell to the next in either direction. The free flow of ions between cells enables rapid non-chemical-mediated transmission. Rectifying channels ensure that action potentials move only in one direction through an electrical synapse. Electrical synapses are found in all nervous systems, including the human brain, although they are a distinct minority. The amplitude of an action