Yuste R, Nelson D A, Rubin W W, Katz L C
Biological Computation Research Department, AT&T Bell Laboratories, Murray Hill, New Jersey 07974.
Neuron. 1995 Jan;14(1):7-17. doi: 10.1016/0896-6273(95)90236-8.
The mammalian neocortex consists of columnar circuits, whose development may be controlled by patterns of spontaneous activity. Columnar domains of spontaneously coactive neurons were previously described using Ca2+ imaging of slices from developing rat neocortex. We have now investigated the cellular mechanisms responsible for the coactivation of these domains. The activation starts in the center of a domain and spreads at speeds of approximately 100 microns/s. Domains occur in the presence of tetrodotoxin but are blocked by the gap junction blockers halothane and octanol. Simultaneous intracellular and optical recordings from dye-coupled cells reveal functional coupling between developing neocortical neurons. These data support the hypothesis that a neuronal domain results from the spontaneous excitation of one or a few trigger neurons that subsequently activate, either electrically or biochemically, the rest of the cells via gap junctions.
