The involvement of brain amines in pinealectomy-induced convulsions in the gerbil: I. Serotonin.

Pharmacological induction of changes in the serotonergic system was used to study the involvement of telencephalic serotonin (5-HT) in pinealectomy (PX) induced convulsions in the gerbil (Meriones unguiculatus). The reactions of the catecholamines norepinephrine (NE) and dopamine (DA) to both PX and drug treatment were also studied. Serotonin is apparently of little importance in the PX-induced convulsion since the artificial elevation by administration of tryptophan and 5-hydroxytryptophan, or depression by treatment with p-chloramphetamine, of telencephalic 5-HT had little effect on the convulsions. In other models for the study of epilepsy, lowered 5-HT results in an increase in seizure intensity. In this study, as in previous ones, telencephalic NE was repeatedly and significantly lowered after PX. None of the serotonergic drugs resulted in changes in NE. Data such as presented here are supportive of previous reports which indicate that a depression of NE facilitates convulsions.