Abstract
Maprotiline removes differences between male and female mice in the Morris water maze. The effects of subchronic administration of maprotiline (15, 20 and 25 mg/kg) on spatial learning, utilising the Morris water maze, and on general activity were assessed in male and f emale mice. In the acquisition phase, maprotiline (15 and 25 mg/kg) impaired learning in males but not in females. Also in this phase, sex differences were not found in the control group. In the retention phase, all three levels of maprotiline removed the sex differences found in the control group. In the general activity test, all three doses of maprotiline decreased activity and removed the sex differences found in the control group. Sexual dimorphism in the effects of maprotiline on spatial learning agrees with findings in studies of the effects of antidepressants and antipsychotics on different learning tasks in mice. When this dimorphism is present, the drug effect is observed only in males or, if present in males and females, it is stronger in the former. The absence of sex differences in the maprotiline treated groups in the retention phase could be due to the anticholinergic pr operties of the drug.
