MOLECULAR PHARMACOLOGY, 45:570-577 Pharmacological Characterization of Metabotropic Glutamate Receptors in Several Types of Brain Cells in Primary Cultures

Several cDNAs coding for metabotropic glutamate receptors (mGIuRl-7) have now been isolated. mGIuR1 and-5 are posi-tively coupled to phospholipase C, whereas mGIuR2,-3,-4,-6, and-7 are negatively coupled to adenylyl cyclase (AC) when they are expressed in Chinese hamster ovary or baby hamster kidney cells. However, the exact transduction mechanisms of these receptors in their natural environment remain to be determined. In a previous work, we demonstrated that stnatal neurons in primary culture expressed a mGIuR that is negatively coupled to AC and that has a pharmacology different from that of mGluR2. In the present study, the pharmacology of mGIuRs negatively coupled to AC in several neuronal types and in glial cells was compared with the pharmacology of mGIuR2,-3, and-4. Like stnatal neurons, cerebral cortical neurons express a mGluR that is able to inhibit AC both in intact cells and in membrane prcpa