Effects of reserpine, alpha-methyl-p-tyrosine, p-chlorophenylalanine and 5,7-dihydroxytryptamine on the hippocampal kindling effect in rats.

The role of the brain monoamines in the development of hippocampal kindling was studied. Reserpine markedly facilitated the formation of hippocampal kindling. The high amplitude spike waves in the amygdala and reticular formation appeared earlier in the reserpine treated rats than in the saline injected rats. alpha-Methyl-p-tyrosine did not have any effect on the formation of hippocampal kindling. Systemic injection of p-chlorophenylalanine and intraventricular injection of 5,7-dihydroxytryptamine also did not have any effect on the formation of hippocampal kindling. Progressive changes of afterdischarge elicited by hippocampal stimulation in the alpha-methyl-p-tyrosine, p-chlorophenylalanine and 5,7-dihydroxytryptamine treated rats are the same as those in the saline injected rats. These results indicate that the decrease in both catecholamines and serotonin levels caused a marked facilitation of the hippocampal kindling formation, but the separate decrease in either catecholamines or serotonin did not produce a significant effect.