Effect of electrical convulsions on uridine labeling and activity pattern in nerve cells in mice

Male white mice were exposed to electroshock and then injected intravenously with 5-[3H]uridine immediately after the shock. After 5, 30, or 60 min or 6, 12, or 24 h, the mice were killed, microautoradiographs were prepared, and grains were counted in the cortex, hippocampus, and basal ganglia. The results of the grain counts were compared with grain counts in the cortex, hippocampus, and basal ganglia of mice exposed to anoxia for 25 s and then treated in the same manner as the first groups. After electroshock the grain count decreased to 25% of that in control animals in the hippocampus and to 50% in the cortex but was normal in the basal ganglia. The counts returned to normal values within 6 h in the hippocampus, and within 1 h in the cortex. After anoxia, the grain counts were normal in the cortex and hippocampus but increased in the basal ganglia. The distribution of cells with a high or low grain count in vertical and horizontal columns of the cortex in control and convulsion animals was analyzed. There were random variations from column to column in both control and convulsion animals. In some anatomic layers there were significantly different grain counts, indicating differences in functional activity.