Although in the model of the co-occurrence of depression and hypothyroidism, stronger changes in PPR in the CA1 region of the hippocampus, the appearance of changes in the level of the active form of ERK, and an increase in the active form of caspase-1 were observed, the changes in basal excitatory transmission were not intensified and, in the case of long-term potentiation in the CA1 region were even decreased, probably due to the substantial differences between the Wistar and WKY strains. Here, CASP1 is linked to major depressive disorder.