Chlordiazepoxide and ethanol additively reduce gustatory negative contrast

Negative contrast that occurs when rats are shifted from 32% to 4% sucrose has been shown to be reduced by chlordiazepoxide (CDP) and ethanol (ETOH). In a previous experiment, doses of 0.75 and 1.0 g/kg ETOH substantially reduced contrast while doses of 0.25 and 0.5 g/kg ETOH were much less effective. In this study, doses of 6 and 8 mg/kg CDP were shown to attenuate the negative contrast effect while smaller doses (2 and 4 mg/kg) influenced contrast to a lesser degree. Evidence for an additive effect of CDP and ETOH on contrast reduction was obtained when 4 mg/kg CDP and 0.5 g/kg ETOH were administered together.