Distribution of metabotropic glutamate receptor mGluR5 immunoreactivity in rat brain

Authors

  • Carmelo Romano,

    Corresponding author
    1. Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110
    2. Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
    • Department of Ophthalmology and Visual Sciences, Box 8096, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110
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  • Michael A. Sesma,

    1. Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110
    2. School of Optometry, University of Missouri-St. Louis, St. Louis, Missouri 63121
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  • Colin T. McDonald,

    1. Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110
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  • Karen O'malley,

    1. Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
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  • Anthony N. van den Pol,

    1. Section on Neurosurgery, Yale University Medical School, New Haven, Connecticut 06510
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  • John W. Olney

    1. Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110
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Abstract

The receptor mGluR5 is a metabotropic glutamate receptor with messenger RNA abundantly present throughout cortex, hippocampus, and caudate/putamen that is also coupled to phosphatidyl inositide hydrolysis and calcium mobilization. In this study, the distribution of mGluR5 was examined in rat brain by immunocytochemistry. The antibody utilized is highly specific and does not cross react with the most closely related other metabotropic glutamate receptor, as determined by Western blot analysis of nonneuronal cells transfected with metabotropic receptor coding sequences. The receptor mGluR5 is widely expressed with the highest density in olfactory bulb, caudate/putamen, lateral septum, cortex, and hippocampus, as confirmed with both immunocytochemistry and Western blot analysis. Electron microscopic studies in hippocampus and cortex indicate that the labeling is mostly on membranes of dendritic spines and shafts. Light and electron microscopic evidence indicates that some mGluR5 immunoreactivity is located in presynaptic axon terminals, suggesting that mGluR5 may function as a presynaptic receptor.

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