Chronic treatment with haloperidol affect the response of the brain to pentobarbital

Treatment of mice with haloperidol increased the number of dopamine D2 receptors (Bmax). The animals were given 40 or 50 mg of pentobarbital. Animals treated with haloperidol had a shorter duration of narcosis induced by pentobarbital than the controls, suggesting a decreased sensitivity to pentobarbital which was functional (CNS), since the animals treated with haloperidol had higher levels of pentobarbital in the brain upon awakening than the controls. The results suggest that increased Bmax reduces the sensitivity of the brain to pentobarbital.