Peculiarities of Fear Memory Disturbance in Male and Female Disc1-Q31L Mice

Depressive disorder is the most common psychopathology that can coexist with other mental illnesses such as post-traumatic stress disorder. It has been shown that there are gender differences in susceptibility to these psychopathologies. Mice of the mutant strain Disc1-Q31L are characterized by depressive-like behavior and disruption of the molecular pathways involved in the processes associated with fear memory. Gender and interstrain differences in the processes of learning and extinction of the conditioned response of passive avoidance were studied in male and female Disc1-Q31L mice and control C57BL/6 mice. It was shown that male and female mice of both strains learned equally well the conditioned response of passive avoidance, but differed in fear memory extinction, the ability to form a new safety memory trace in the previously dangerous dark compartment of the setup. However, there was a deficit in the extinction of the conditioned response of passive avoidance in C57BL/6 females compared to males, as well as interstrain differences in the dynamics of extinction in both females and males. Disc1-Q31L males reached full extinction later than C57BL/6 males, while Disc1-Q31L females did not exhibit extinction during the 24 days of the test. Thus, this work shows the interaction of the effect of gender and the Disc1-Q31L mutation on the processes of fear memory extinction.