Saccharin reverses the effect of food deprivation upon fluid intake in mice

Abstract

Hungry mice drank less when water was the only available fluid, but they drank more when a maximally preferred solution of saccharin was provided instead of water. The ingestion of saccharin did not ameliorate weight loss and appeared to serve no adaptive function. The saccharin effect was more pronounced in strain C57 BL 6 J than in strain DBA 2 J , which has a weaker preference for saccharin. During food deprivation saccharin preference scores rose in both strains. The correlation between changes in preference and changes in blood glucose was high during one period of food deprivation, but non-significant during a second period. There may be little causal relationship between these two variables. Taste can affect control mechanisms for fluid intake, thus reversing the usual decrease of drinking in food-deprived animals. We suggest that in such animals control of drinking a saccharin solution is shifted from a thirst motivation system to a hunger motivation system.