Chronic choline supplementation attenuates the behavioral effects of pentobarbital

The behavioral and neurochemical effects of pentobarbital were investigated in rats maintained for 28-35 days on a standard choline-containing diet or on a diet containing 10 times the concentration of choline present in standard rodent chow. The supplemented dietary regimen increased the concentration of free choline in serum by 52%, but did not alter the steady-state concentrations of either choline or acetylcholine in brain. Choline supplementation attenuated both the sedative/hypnotic and hypothermic effects of pentobarbital through an action that could not be attributed to either an enhanced peripheral metabolism of pentobarbital or to an attenuation of the cholinergic effects of pentobarbital. Rather, results indicate that chronic supplementation with choline increases cerebral glucose metabolism and causes a behavioral hyperactivity, effects that may mediate the attenuation of the behavioral response of pentobarbital.