The role of noradrenergic and serotonergic systems in the hippocampal kindling effect

The role of the noradrenergic and the serotonergic systems in the development of hippocampal and amygdaloid kindling was studied. Dorsal noradrenaline bundle lesions markedly facilitated the formation of hippocampal and amygdaloid kindling. The most significant facilitation was observed in the earliest phase of kindling. Cortical noradrenaline content decreased by about 70% after dorsal noradrenaline bundle lesions. Midbrain raphe nuclei (both dorsal and medial raphe nuclei) lesions did not have any effect on the formation of both hippocampal and amygdaloid kindling. These results indicate that the dorsal noradrenaline bundle system plays an inhibitory role in the development of the seizure discharges and the behavioral convulsions in hippocampal and amygdaloid kindling.