Gap Junctions in the Nervous System

Gap junctions in the nervous system fulfill vital functions of signal transmission and metabolite delivery and buffering. Between neurons, gap junctions form electrotonic synapses providing rapid bidirectional relay that is essential for rapid and synchronous activities. Between glial cells, gap junctions provide a route for long-range intercellular calcium signaling, as well as delivery of glucose and buffering of potassium ions. A family of connexin proteins comprises gap junctions with cell-specific expression, and mutations in the genes that encode connexins are responsible for a number of neurological diseases including the X-linked form of Charcot-Marie-Tooth disease, hereditary nonsyndromic deafness, and oculodentodigital dysplasia.