Effects of Ro 4-1284 on electrically-induced spinal cord seizures and on spinal cord norepinephrine and 5-hydroxytryptamine levels.

The time course effects of the benzoquinolizine Ro 4-1284 on spinal cord norepinephrine (NE) and 5-hydroxytryptamine (5-HT) levels were compared to the effects of this same drug on electrically-induced spinal cord seizures. The data show that a significant decrease in spinal cord NE levels and a facilitating effect on spinal cord seizures are apparent 15 minutes after Ro 4-1284 (10 mg/kg s.c.) and that both of these effects persist for at least 24 hours. Forty-eight hours after injection, the effects of Ro 4-1284 on seizure and on NE levels are completely dissipated. A significant decrease in 5-HT levels is not apparent until 1 hour after Ro 4-1284. These data suggest that noradrenergic neurons of the spinal cord act as attenuators of seizure activity. The possibility that spinal cord 5-HT also subserves a seizure attenuating function is not precluded.