Anisomycin disrupts consummatory behavior after incentive downshift via conditioned taste aversion

The protein synthesis inhibitor anisomycin was tested in the consummatory successive negative contrast paradigm (cSNC). The cSNC effect involves suppression of consummatory behavior induced by 4% sucrose in animals that previously received 32% sucrose (downshifted), relative to animals that always received 4% sucrose (unshifted). Systemic anisomycin (25 mg/kg, ip) induced suppression in both downshifted and unshifted groups when injected before the first or second downshift trial (Experiment 1) or after the first downshift trial (50 mg/kg, ip; Experiment 2). The effect of anisomycin (50 mg/kg, sc) administration after the first downshift trial was observed only in downshifted animals in Experiment 3, but the same dose and route of administration induced significant conditioned taste aversion in Experiment 4. It was concluded that a conditioned taste aversion to the 4% sucrose solution accounts most parsimoniously for all the results. Implications for other experiments involving posttrial anisomycin administration are discussed.