Short communicationSex differences in the acute locomotor response to methamphetamine in BALB/c mice

- Female and male BALB/c mice were administered methamphetamine and open-field locomotor activity was assessed.
- Female BALB/c mice displayed an enhanced response to the locomotor-activating effects of methamphetamine compared to males.
- Basal locomotor activity was positively correlated with locomotor responses to methamphetamine in male, but not female BALB/c mice.

Women use methamphetamine more frequently than men and are more vulnerable to its negative psychological effects. Rodent models have been an essential tool for evaluating the sex-dependent effects of psychostimulants; however, evidence of sex differences in the behavioral responses to methamphetamine in mice is lacking. In the present study, we investigated acute methamphetamine-induced (1 mg/kg and 4 mg/kg) locomotor activation in female and male BALB/c mice. We also evaluated whether basal locomotor activity was associated with the methamphetamine-induced locomotor response. The results indicated that female BALB/c mice displayed enhanced methamphetamine-induced locomotor activity compared to males, while basal locomotor activity was positively correlated with methamphetamine-induced activity in males, but not females. This study is the first to show sex-dependent locomotor effects of methamphetamine in BALB/c mice. Our observations emphasize the importance of considering sex when assessing behavioral responses to methamphetamine.