Repeated cocaine administration increases cleaved poly(ADP-ribose) polymerase-1 expression in the rat dorsal striatum

Poly(ADP-ribose) polymerase-1 (PARP-1) expression is associated with the endoplasmic reticulum (ER) stress response in neurons. In this study, the regulation of PARP-1 activation by repeated cocaine administration in the rat dorsal striatum was investigated in vivo. Our results demonstrated that repeated systemic injections of cocaine (20 mg/kg) once a day for 7 days increased cleaved PARP-1 expression. This increase was reduced by blocking dopamine D1, but not dopamine D2, receptors. The blocking of group I metabotropic glutamate receptors (mGluRs), mGluR1 subtype, and N-methyl- d-aspartate receptors also reduced cocaine-stimulated cleaved PARP-1 expression. Taken together, these findings suggest that PARP-1 activation is upregulated by repeated cocaine administration, and that interactions between dopamine D1 and glutamate receptors may be involved in this upregulation.