Effect of Alpha-Methyltyrosine on Sleep in the Rat

Abstract

Three successive intraperitoneal injections of 50 mg/kg alphamethyltyrosine at 4-hr. intervals failed to produce significant changes in percentage of time spent sleeping or in percentage of sleep in the paradoxical phase in rats. Similar injections in subsequently sacrificed rats produced a depletion of more than 50% in whole brain norepinephrine without significantly changing brain serotonin levels. The results fail to support the hypothesis of a major mediating role for norepinephrine in the regulation of paradoxical sleep or sleep per se.