Glutamate release inhibiting properties of the novel mGlu(5) receptor antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP): complementary in vitro and in vivo evidence

We have previously demonstrated that neuronal release of the excitatory ami no acid glutamate is facilitated by the selective activation of presynaptic Group I metabotropic autoreceptors. Here we report the release inhibiting actions of the novel mGlu(5) receptor-selective antagonist, 2-methyl-6-(phe nylethynyl)-pyridine (MPEP), both in vitro and in vivo. These data provide compelling evidence for the presence of functional positive modulatory mGlu (5) subtype autoreceptors in the mammalian central nervous system. (C) 2001 Published by Elsevier Science Ltd.