Some functional effects of suppressing bioelectric activity in fetal mouse spinal cord-dorsal root ganglion explants

Organotypic explants of fetal mouse spinal cord-dorsal root ganglia were grown for 3 weeks in the presence of 10 mM magnesium ion, which effectively eliminated all recordable bioelectric activity throughout the culturing period. When tested in minimal essential medium, the chronically silenced explants had significantly fewer points from which spontaneous neuronal activity could be recorded. In addition, fewer points could be found that showed dorsal root ganglion-evoked responses, resulting from a greater tendency for the spinal cord activity to be restricted to the vicinity of the dorsally entering DRG fibers. These findings, therefore, support the hypothesis that spontaneous bioelectric activity is required for functional as well as structural maturation of neural networks.