Analysis of the spatial distribution of gap junctions relative to chemical synapses on serial ultrathin sections of the rat barrel cortex

摘要

Electron microscope studies of gap junctions (GJ) on serial sections of the barrel cortex in rats showed that GJ make contact with one or both of the processes forming chemical synapses, though these associations could not be demonstrated on single sections. On serial sections, a single field could show two GJ close together, and each GJ could be followed through 2-3 sections in the series. Given the variants described for the distribution of GJ in the cortex, it is suggested that GJ may provide the structural basis for local synchronization of bioelectrical activity not only at the postsynaptic, but also at the presynaptic level; formation of GJ occurs both before and after development of chemical synapses.