Trichloromethane-induced taste aversions in mice

In Experiment 1 four groups (N = 10) of individually housed mice were given access to deionized water for 30 min daily. When fluid consumption stabilized, they were given 30-min access to a 0.3% saccharin solution. This was followed by oral doses of 3, 10 or 30 mg/kg trichloromethane (TCM) or the vehicle (Emulphor). Beginning 24 hr later the subjects were given a two-bottle choice test (saccharin vs water) followed by the appropriate injection in that group. This procedure continued for 10 days. A dose of 30 mg/kg produced a taste aversion on the first choice test and a reduction in total fluid intake which continued throughout the 10-day test period, while doses of 3 and 10 mg/kg TCM or vehicle did not affect either measure. To determine whether the aversion produced by 30 mg/kg TCM was specific to gavage, animals in Experiment 2 received IP injections of 10, 30 or 100 mg/kg TCM or vehicle. All TCM groups showed taste aversions which lasted for the 10-day test period. Although concomitant fluid reductions occurred for all doses on day one, only the 100 mg/kg group maintained this drop throughout the 10-day test period. Thus, TCM produces taste aversions when given at relatively low doses by both oral and IP routes of administration.