Dopaminergic influence on withdrawal jumping behavior in morphine-dependent mice

Abstract

Abrupt withdrawal jumping behavior in morphine-dependent mice is accompanied by a decrease in brain dopamine turnover and an increase in brain dopamine level which parallel strain differences in jumping incidence. Both naloxone-precipitated and abrupt withdrawal jumping behavior are inhibited in a dose-dependent manner by the dopaminergic agonist apomorphine. A cataleptic dose of the dopaminergic antagonist, haloperidol, does not block naloxone-precipitated jumping, but does significantly block the inhibition by apomorphine. These findings indicate that there may be a decrease release of dopamine in the brain during the expression of withdrawal jumping behavior and that dopaminergic activation may be inhibitory to this behavior.