Effects of anticonvulsants on the electroconvulsive threshold lowered by DA, 5-HT or GABA depletion

A cannula was chronically implanted in the rat ventriculus, and anticonvulsants were administered through the cannula. The effects of the anticonvulsants applied, intraventricully, were investigated on the decreased electroconvulsive threshold induced by pretreatment with alpha-methyl-p-tyrosine (alpha-MT), p-chlorophenylalanine (PCPA) or allylglycine. The TRH analog, DN-1417, valproate (VPA), and phenobarbital (PB) raised the electroconvulsive threshold which had been lowered by alpha-MT. The reduced electroconvulsive threshold from PCPA was raised by DN-1417, but not by VPA or PB. The allylglycine induced lowering of the electroconvulsive threshold was raised by VPA and PB, but not by DN-1417. Phenytoin had no anticonvulsant effect on rats pretreated with these drugs. From these results, it was concluded that the anticonvulsant action of DN-1417 could be due to enhancement of dopamine and/or serotonin turnover.