GABAergic influences on barbital withdrawal induced convulsions.

Animals which had been long-term treated with increasing concentrations of sodium barbital in the drinking water were killed 30 min or 72 hr after the last day of treatment, to determine striatal GABA levels and turnover rate. The effects of pentobarbital administration on GABA metabolism of rats withdrawn or not withdrawn from barbital were also studied. Barbital withdrawal induced a significant decrease in striatal GABA levels and also in the turnover rate after pentobarbital treatment. The latter effect was greater in rats killed 72 hr after drug removal. In control animals, pentobarbital treatment increased striatal GABA levels but did not affect the turnover rate. Barbital removal also made the rats less responsive to the effects of pentobarbital on striatal GABA levels. These results suggest the participation of a central GABAergic system in barbital withdrawal convulsions.