Ethanol intake is not elevated in male 5-HT1B receptor knockout mice

Recently, the phenotype of increased ethanol intake in mice lacking 5-HT1B receptors could not be replicated. We assessed ethanol consumption in male wildtype and 5-HT1B receptor knockout mice derived from the original popula tion. Intake of water and ethanol (0%, 3%, 6%, 10% and 20% v/v) from two pi pettes was determined daily for 40 days. Ethanol intake (g/kg body weight) did not differ between genotypes, while body weights (20-25%) and water int ake (50%) were elevated in 5-HT1B receptor knockout mice. Hence, the initia l finding of elevated ethanol intake in 5-HT1B receptor knockout mice may h ave been due to phenotypic differences in fluid intake. (C) 2000 Elsevier S cience B.V. All rights reserved.