Characteristics of the Formation of Memories Relating to Fear in Mice with Depression- and Schizophrenia-Like Phenotypes: Effects of Gender and Age

We report here a comparative analysis of the acquisition of a conditioned passive avoidance reaction in mice of the mutant strains DISC1-Q31L and DISC1-L100P and mice of the control strain C57Bl/6NCr1 and detection of the effects of gender and age on learning. DISC1-L100P mice showed impairments to associative learning to avoid the dangerous dark sector of the apparatus regardless of gender and age. In DISC1-Q31L mice, the fear memory trace formed only in young males. A deficit of aversive learning was demonstrated in old mice of all the strains tested, with identically lower levels of learning ability in female DISC1-Q31L and C57Bl/6NCr1 mice than males. These characteristics of learning avoidance provide an additional argument for regarding DISC1-L100P mice as a genetic model of a schizophrenia-like state and DISC1-Q31L mice as a model of a depression-like state.