THE ANXIOLYTIC-LIKE EFFECT OF METABOTROPIC GLUTAMATE-RECEPTOR ANTAGONISTS AFTER INTRAHIPPOCAMPAL INJECTION IN RATS

Using the conflict drinking Vogel test in rats as a model we examined the anxiolytic-like activity, after their intrahippocampal administrat ion of (S)-4-carboxy-3-hydroxyphenyl-glycine (S-4C3H-PG), (RS)-alpha-m ethylserine-O-phosphate-monophenyl ester (MSOPPE) and (RS)-alpha-methy lserine-O-phosphate (MSOP), the antagonists of the I, the II and the I II group of metabotropic glutamate receptors (mGlu receptors), respect ively. The results indicate that S-4C3H-PG and MSOP produced a dose-de pendent anticonflict effect in rats, which was unrelated to a reduced perception of the stimulus or to an increased thirst drive. The hippoc ampus may be one of the neuroanatomical sites of the anxiolytic-like e ffects of both mGlu receptor antagonists.