Casein kinase 1 enables nucleus accumbens amphetamine-induced locomotion by regulating AMPA receptor phosphorylation

摘要

The closely related 8 and s isoforms of the serine/threonine protein kinase casein kinase 1 (Csnki) have been implicated in the generation of psychostimulant-induced behaviors. In this study, we show that Csnki 8/s produces its effects on behavior by acting on the Darpp-32-PP1 signaling pathway to regulate AMPA receptor phosphorylation in the nucleus accumbens (NAcc). Inhibiting Csnki S/e in the NAcc with the selective inhibitor PF-670462 blocks amphetamine induced locomotion and its ability to increase phosphoryiation of Dar-pp-32 at S137 and T34, decrease PP1 activity and increase phosphorylation of the AMPA receptor subunit at S845,Consistent with these findings, preventing GluR1 phosphorylation with the alanine mutant GluR1 (S845A) reduces gluta-mate-evoked currents in cultured medium spiny neurons and blocks the locomotor activity produced by NAcc amphetamine. Thus, Csnki enables the locomotor and likely the incentive motivational effects of amphetamine by regulating Darrp-32-PP1-GlurR1{S845) signaling in the NAcc. As such, Csnki may be a critical target for intervention in the treatment of drug use disorders.