WAY-100635 Maleate

WAY-100635 is a potent and selective 5-hydroxytryptamine1A antagonist with an IC50 of 0.95 ?0.12 nM for 5-HT. Intravenous administration of WAY-100635 (0.025-0.5 mg/kg) markedly improved neuronal activity. The stimulatory action of WAY-100635 was evident during wakefulness (when serotonergic neurons typically display a relatively high level of activity) but not during sleep (when serotonergic neurons display little or no spontaneous activity). WAY-100635 at doses as low as 0.1 mg/kg i.v. completely blocked the action of 8-hydroxy-2- (di-n-propylamino)tetralin. The antagonist action of WAY-100635 at 5-HT1A autoreceptors closely paralleled its ability to increase neuronal activity. WAY-100635 affected neither the blackage of action potential frequency adaptation and slow afterhyperpolarization produced by 5-HT (15 μM) nor the hyperpolarization and decrease in membrane input resistance evoked by bath application of GABA (B) receptor agonist baclofen (10 μM).