Effect of brain serotonin level on induced hippocampal paroxysmal activity in rats.
Experiments were performed to study the involvement of brain 5-HT in an experimental model of epilepsy induced by repeated electrical stimulation of the dorsal hippocampus of rats. The experiments included: (1) systemic injections of 5-hydroxytryptophan (5-HTP) and p-chlorophenylalanine (pCPA) and (2) electrolytic lesions of the midbrain raphe nuclei. The pCPA group showed a significant increase while animals which received systemic injections of 5-HTP showed a great reduction in the electrographic seizure activity. Although several reports have shown that midbrain raphe lesions do not modify the epileptic susceptibility, we observed a clear enhancement in the epileptiform activity in lesioned animals. The results presented here support the view that serotonergic systems may exert a tonic inhibitory effect on hippocampal epileptic activity.
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004558:Electric Stimulation; D004569:Electroencephalography; D010134:Fenclonine / Q000494:pharmacology; D006624:Hippocampus / Q000503:physiopathology*; D008297:Male; D011903:Raphe Nuclei / Q000601:surgery; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin; D006916:5-Hydroxytryptophan; D010134:Fenclonine