Alcohol preference in the rat: reduction following depletion of brain serotonin.

Preference for ethyl alcohol was significantly reduced or totally abolished in rats given orally p-chlorophenylalanine, a tryptophan hydroxylase inhibitor that selectively depletes brain serotonin. Some aversion to alcohol was observed while p-chlorophenylalanine was administered, but the rats' rejection of alcohol was even more marked after the drug was discontinued. Oral administration of alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor that depletes brain catecholamines, slightly reduced selection of alcohol, but preference returned to normal as soon as alpha-methyl-p-tyrosine was terminated.