Intercellular Communication in Arthropods

摘要: The gap junction is one form of membrane specialization that appears in the electron microscope as a closely apposed region plasma separating adjacent cells contact by 2- to 5-nm-wide “gap,” from which name derived (Revel and Karnovsky, 1967). In freeze-fracture replicas viewed microscopy, junctions are composed tightly packed clusters particles (Kreutziger, 1968). Each particle presumably represents site single intramembrane channel connects with cell allowing direct exchange or “communication” ions other small molecules. functions these “communicating channels” spectrum activities they regulate now beginning be realized. excitable tissues, synonymous electrical synapses sometimes referred nexus (Dewey Barr, 1962). Gap allow rapid signaling coordination smooth cardiac muscle contraction. It apparent, however, role nervous system can more complex may also modify behavior discrete populations neurons (Getting, 1974; Getting Willows, Rayport Kandel, 1980; Dudek et al., 1983; Marder, 1984; Bennett 1985). nonexcitable tissues include, but not limited to, tissue homeostasis (metabolic cooperation, i.e., sharing metabolites), response hormones neurotransmitters, and, lower invertebrates, adhesion.