Dopamine D1 and NMDA Receptors Interaction in the Dorsal Hippocampus of Rats in the Elevated Plus Maze Test of Anxiety

In this study the effects of dopaminergic D1 receptor of dorsal hippocampuson anxiety-like behavior induced by stimulation or inhibition of NMDA receptors wereinvestigated in male Wistar rats. The elevated plus maze was used in thepresent study, which is an accepted model to examine anxiety-like behaviors in mice andrats. The results indicate that intra-CA1injection of MK801 (2 μg/rat) induceanxiolytic effects. Intra-CA1 injection of SCH23390 (0.25, 0.5 and 1 μg/rat) by itselfhas no effect on anxiety-like behaviors, but administration of same doses of SCH23390before MK801 (1 μg/rat, intra-CA1) potentiate anxiolytic effects of MK801. On the otherhand, intra-CA1 injection of NMDA (0.3 and 0.6 μg/rat) or SKF 38393 (3 and 6 μg/rat) byitself induces anxiogenic effects. Injection of different doses of SKF38393 before NMDApotentiated anxiogenic effects of NMDA. These results show that bothNMDA receptor and dopaminergic D1 receptor not only play a part in the modulationof anxiety in the dorsal hippocampus of rats but also have demonstrated a complexinteraction as well.