Stimulation of group II metabotropic glutamate receptors or inhibition of group I ones exerts anxiolytic-like effects in rats

Summary.

Using the conflict drinking Vogel test in rats as a model we examined the anxiolytic-like activity of (S)-4-carboxyphenylglycine (S-4CPG), an antagonist of group I metabotropic glutamate receptors (mGlu receptors), of (RS)-α-methylserine-O-phosphate-monophenyl ester (MSOPPE), an antagonist of group II mGlu receptors, and of (2S,1′S,2′S)-2-(carboxycyclopropyl)glycine (L-CCG-I), an agonist of group II mGlu receptors. The obtained results indicate that intrahippocampal administra-tion of S-4CPG and L-CCG-I, but not MSOPPE to rats produces a dose-dependent anticonflict effect, which is unrelated to the reduced perception of the stimulus or to an increased thirst drive. The hippocampus may be one of the neuroanatomical sites of the anxiolytic-like effects of either agent.