Evidence that GABA and glycine-like inputs inhibit vasodepressor neurons in the caudal ventrolateral medulla of the rabbit.

Local microinjections of muscimol and glycine into the caudal ventrolateral medulla of the rabbit, caused an acute increase in arterial blood pressure. Bicuculline and strychnine, antagonists of these agents, acutely decreased arterial pressure when microinjected into the same region. Control injections placed 1.5 mm medially did not affect arterial pressure. The pressure changes were independent of heart rate changes and were prevented by prior cervical cord transection. Results suggest that vasodepressor neurons in the caudal ventrolateral medulla are themselves inhibited by GABA and glycine-like inputs.