Sex differences in mouse models of fear inhibition: Fear extinction, safety learning, and fear–safety discrimination

Abstract

Background and Purpose: Women are overrepresented in post-traumatic stress disorder (PTSD), a mental disorder characterised by ineffective inhibition of fear. The use of male animals dominates preclinical studies, which may contribute to a lack of understanding as to why this disparity exists. Thus, the current study explores sex differences in three mouse models of fear inhibition. Experimental Approach: All experiments tested male and female C57Bl/6J mice. Experiment 1 employed two fear conditioning protocols, in which tones were paired with footshocks of differing intensity (moderate or intense). Fear recall and extinction were tested subsequently. In Experiment 2, safety learning was inv..