Abstract
Adult mice were exposed to long-term phencyclidine (PCP) treatments as animal models for psychosis. The drug was administered via osmotic minipumps implanted subcutaneously in the backs of the mice. The treatments for 7 days with 2.5 and 1 mg/d/mouse and the treatment for 3 days with 1 mg/d/mouse differentially affected the release of dopamine and D-aspartate from striatal and frontal cortical slices. In frontal cortical slices the potassium-stimulated release of dopamine increased, whereas the release of D-aspartate varied with the PCP dose. In striatal slices the release of D-aspartate was either decreased or unchanged, whereas the release of dopamine was mostly unchanged. The 3-day treatment with PCP followed by the 3-day period of withdrawal increased the potassium-stimulated release of dopamine from frontal cortical slices and decreased that from striatal slices. In brain slices from untreated mice PCP increased the release of dopamine in vitro, whereas the release of D-aspartate was not affected. It seems that PCP has region-specific effects on both dopaminergic and glutamatergic transmission in the central nervous system, and it may thus serve as an interesting experimental model for further research on psychosis.