Abstract
Effects of morphine on locomotor activity in male mice. Morphine produces dramatical effects on locomotor activity, although controversial results are found since the behavioural profile of this drug can vary in function of several parameters such as doses, time elapsed after administration and species used. In this study we investigate the effect of 0.7, 2.1, 6.3 and 18.9 mg/kg of morphine on locomotor activity of male mice at 30 minutes after the drug during 30 minutes, recording activity each five minutes with an actimeter. Results showed that only the dose of 6.3 mg/kg of morphine produced a significant decrease of activity at 10 minutes of test with respect to control. It would indicate that the effect of morphine on locomotor activity could vary in function of the time and the doses administered.