[The initial level of motor activity determines the directivity of the motor effect of apomorphine]. / Iskhodnyi uroven' dvigatel'noi aktivnost' opredeliaet napravlennost' motornogo éffekta apomorfina.

In male mice of BALB/c and SHR strains with the highest base level of locomotion and rearings apomorphine (5 mg/kg) decreased these forms of motor activity while in C57BL/6 mice with the lowest base level of motor activity apomorphine increased it. In mice of C57BR and C3H/A strains with intermediate base level there was a tendency for an increase in activity. Extinction of exploratory motor activity in BALB/c as a result of four consecutive testings in the same experimental chamber with hourly intervals induced a decrease in activity of the animals by half. Being injected against this background the same dose of apomorphine (5 mg/kg) twice increased locomotion and rearings in these mice.