GAP JUNCTIONAL COMMUNICATION AND THE DEVELOPMENT OF LOCAL CIRCUITS INNEOCORTEX

In the neocortex, as well as in many other brain regions, neurons resp onding to similar stimulus features are usually found close to one ano ther. Here we examine the possible role of gap junctional communicatio n in forming and defining these local neuronal groupings, examples of which may be the columns found in the neocortex of virtually all mamma lian species. We have approached this question experimentally in corti cal brain slices using calcium imaging to visualize multicellular acti vity patterns, and tracer injections to identify the anatomical patter n of gap junction coupling in the developing neocortex. Our results su ggest that dendrodendritic gap junctional communication may be involve d in the formation of local connectivity, most likely by synchronizing electrical or biochemical activity among neighboring neurons.