Learned aversions to copulatory behaviors in male rats.

When male rats received an injection of lithium chloride immediately after an encounter with an estrous female, the vigor of subsequent copulatory responding was initially unaffected. After 5 to 10 such pairings, however, male rats displayed an aversion to copulatory behaviors; they ceased to copulate entirely. These aversions persisted when the rats were tested in a novel environment and extinguished after four nonreinforced trials. This multiple-trial adaptation of the conditioned taste aversion paradigm provides a new approach to the aversive control of sexual behavior.