Localization of mGluR4 protein in the rat cerebral cortex and hippocampus

The cellular distribution of the rat metabotropic glutamate receptor type 4 (mGluR4) was examined in the adult rat cerebral cortex and hippocampus. Antibodies were raised against amino acid residues located in the extracellular amino terminal domain that is common to both the mGluR4a and mGluR4b splice variants, and used for an immunohistochemical investigation. The affinity-purified antibodies on immunoblot analysis specifically detected mGluR4 protein in transfected mammalian cells, showing no cross-reactivity with other members of the mGluR family. At the light microscope level intense mGluR4-like immunoreactivity was detected in the CA2 region of Ammon's horn in the hippocampus. In the cerebral cortex numerous non-pyramidal cells were strongly immunolabelled.