Alteration of seizures resulting from pinealectomy in the rat after neonatal treatment with 6-hydroxydopamine.

Convulsions from combined pinealectomy and parathyroidectomy were examined in rats treated as neonates with 6-hydroxydopamine (6-OHDA). Injection of 6-OHDA caused a significant reduction in the average latency to onset of clonic-tonic convulsions. Moreover, of the 6-OHDA-treated rats which convulsed, nearly half of them died during a seizure. In sham-pinealectomized rats, neonatal treatment with 6-OHDA reduced norepinephrine (NE) and increased dopamine levels in the forebrain while brainstem levels of NE were increased. Pretreatment with desmethylimipramine reversed the effects of 6-OHDA on convulsions and catecholamine levels. The results indicate that catecholamine lesions with 6-OHDA exacerbate convulsions from pinealectomy.