Ketamine retards recovery from reward downshift and supports conditioned taste aversion.
Pharmacology, biochemistry, and behavior October 28, 2023 Antonio D R Agüera, Clara Cándido, Rocío Donaire et al. 4 citations
Ketamine, an NMDA receptor antagonist with known antidepressant and memory effects, was tested in rats undergoing a reward-downshift task that induces frustration and aversive memory. Male rats given 32% sucrose then unexpectedly shifted to 4% sucrose showed greater suppression of intake when injected with ketamine (10 mg/kg) either before or after the first downshift session, compared to saline-injected controls. This suppression lasted beyond the injection days. In separate experiments, the same ketamine dose produced conditioned taste aversion to 4% sucrose even without reward downshift. The findings suggest ketamine creates an aversive state that adds to frustration from reward loss and can itself support conditioned taste aversion.