Cholecystokinin system in striatal-nigral neuronal networks: infusion of quinolinic acid into rat striatum

Abstract

Unilateral infusions of quinolinic acid (QUIN) into the rat striatum led to an increase in cholecystokinin octapeptide sulfate-like immunoreactivity (CCK8S-LI) in the striatum and substantia nigra 4 days later. These changes were suppressed by the injection of gamma-aminobutyric acid into substantia nigra 30 min before sacrifice. Intraperitoneal administration of haloperidol 40 min before sacrifice also suppressed the effect of QUIN on CCK. These results suggest that nigrostriatal dopaminergic neurons regulate CCK neurons via presynaptic sites in the striatum, and also that striatonigral GABAergic neurons interact with CCK neurons in the substantia nigra.