Electrical synapses in the mammalian brain.
Many neurons in the mammalian central nervous system communicate through electrical synapses, defined here as gap junction-mediated connections. Electrical synapses are reciprocal pathways for ionic current and small organic molecules. They are often strong enough to mediate close synchronization of subthreshold and spiking activity among clusters of neurons. The most thoroughly studied electrical synapses occur between excitatory projection neurons of the inferior olivary nucleus and between inhibitory interneurons of the neocortex, hippocampus, and thalamus. All these synapses require the gap junction protein connexin36 (Cx36) for robust electrical coupling. Cx36 appears to interconnect neurons exclusively, and it is expressed widely along the mammalian neuraxis, implying that there are undiscovered electrical synapses throughout the central nervous system. Some central neurons may be electrically coupled by other connexin types or by pannexins, a newly described family of gap junction proteins. Electrical synapses are a ubiquitous yet underappreciated feature of neural circuits in the mammalian brain.
Connors
Barry W
BW
Department of Neuroscience, Brown University, Providence, Rhode Island 02912, USA. BWC@Brown.edu
Long
Michael A
MA
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001921:Brain / Q000502:physiology* / Q000648:ultrastructure; D002415:Cats; D002450:Cell Communication / Q000502:physiology; D017630:Connexins / Q000502:physiology; D017629:Gap Junctions / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D008322:Mammals; D051379:Mice; D009419:Nerve Tissue Proteins / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure; D000097004:Gap Junction delta-2 Protein
D017630:Connexins; D009419:Nerve Tissue Proteins; D000097004:Gap Junction delta-2 Protein; C479936:pannexin 1, rat