Carbon dioxide uncouples dye-coupled neuronal aggregates in neocortical slices

Lucifer Yellow was injected intracellularly into neurons in slices of guinea pig visual cortex. Dye coupling incidence was significantly decreased in slices that were incubated in a high concentration of carbon dioxide. This effect was probably due to intracellular acidification, since exposure to impermeant acid was not effective. The data are consistent with the hypothesis that carbon dioxide interferes with dye coupling in neocortex through its known action as an uncoupler of electronic coupling through gap junctions.