[Effects of chronic imipramine treatment on behavior in mice of congenic strains AKR and AKR.CBA-D13Mit76 differing in the distal fragment of chromosome 13].

Congenic mouse strain AKR.CBA-D13Mit76 carries the 59-70 cM fragment of chromosome 13 transferred from genome of cataleptic CBA/Lac strain to genome of AKR/J none-cataleptic strain. This fragment contains the major gene of predisposition to pinch-induced catalepsy. We investigated contribution of the fragment to regulation of sensitivity of catalepsy, sexual motivation and social investigation to classical tricyclic antidepressant imipramine. The sexual motivation was higher in AKR.CBA-D13Mit76 than in AKR mice. Chronic imipramine treatment (25 mg/kg) reduced it in AKR.CBA-D13Mit76 mice and had no effect on weakly expressed sexual motivation of AKR males. No significant effects of genotype or chronic imipramine treatment on characteristics of social interest were observed. Imipramine failed to alter catalepsy expression in AKR.CBA-DI3Mit76 mice. Possible molecular genetic mechanisms underlying difference in behavioral responses to antidepressant administration are discussed.