Alterations in adult behavioral responses to cocaine and dopamine transporters following juvenile exposure to methamphetamine

The present experiment assessed whether preadolescent exposure to methamphetamine would alter adult behavioral responses to cocaine and dopamine transporter immunoreactivity in the striatum of male and female rats. Juvenile rats were injected once daily with 0 or 2 mg/kg methamphetamine from postnatal days 21 to 35 and tested in adulthood. Male rats, but not female rats, exposed to methamphetamine showed an increase in responsiveness to cocaine in the open field and an increase in dopamine transporter immunoreactivity in the striatum. These findings suggest that early exposure to methamphetamine can lead to sex specific altered responses to psychostimulants in adulthood, which may contribute to later vulnerability to drug use.

Research highlights▶ Juvenile exposure to methamphetamine alters dopamine mediated behavior in adult male, but not female, rats. ▶ Juvenile exposure to methamphetamine increases dopamine transporters in the striatum of adult male rats. ▶ The long-term effects of juvenile methamphetamine exposure are sex specific.