Changes in dopamine D2 and GluR-1 glutamate receptor mRNAs in the rat brain after treatment with phencyclidine

In situ hybridization of slide-mounted brain sections from rats subjected to acute and chronic phencyclidine treatment was carried out using synthetic oligonucleotides complementary to dopamine D2-receptor and non-N-methyl-D-aspartate (NMDA) glutamate-receptor-subunit (GluR-1) mRNAs. There was no significant difference in either the D2-receptor or the GluR-1 mRNA levels in any brain region of the acute phencyclidine (10 mg/kg)-treated and control groups. However, chronic administration of phencyclidine (10 mg/kg/day, 14 days) significantly decreased the dopamine D2-receptor mRNA level in the caudate-putamen (by 27%, P < 0.01) and significantly increased the GluR-1 mRNA level in the prefrontal cortex (by 29%, P < 0.001). These results suggest that the chronic pharmaco-behavioral effects of phencyclidine may involve expression of both dopamine- and non-NMDA glutamate-receptor mRNAs.