Renewal of conditioned fear in a third context after either extinction or counterconditioning: Testing the effects of sex and hormones.

A series of experiments tested the role of sex and cycling ovarian hormones in the renewal of conditioned freezing after either extinction or counterconditioning. In all experiments, conditioning occurred in Context A, response reduction (extinction or counterconditioning) occurred in Context B, and renewal occurred in a familiar yet neutral Context C. Experiment 1a compared renewal after extinction for male and female rats. Both groups demonstrated robust renewal. This finding was replicated in Experiment 1b, which also included a group of ovariectomized female rats to test a potential role of cycling ovarian hormones. Renewal was present and did not differ between groups. Experiment 2 extended these findings to examine renewal after aversive-to-appetitive counterconditioning. Once again, renewal did not differ between male and female rats (Experiment 2a), nor between male, intact female, and ovariectomized female rats (Experiment 2b). For all experiments, summation testing failed to detect differential context-U.S. associations between Contexts B and C. We discuss the role for cycling ovarian hormones in renewal, noting methodological differences with prior studies, and we also discuss how contexts can influence behavior during either extinction or counterconditioning. (PsycInfo Database Record (c) 2025 APA, all rights reserved).