Non‐NMDA glutamate receptors are present throughout the primate hypothalamus

SD Ginsberg, DL Price, CD Blackstone… - Journal of …, 1995 - Wiley Online Library
Journal of Comparative Neurology, 1995Wiley Online Library
To determine the distributions of glutamate receptors throughout the macaque
hypothalamus, we utilized highly specific antipeptide antibodies to visualize α‐amino‐3‐
hydroxy‐5‐methyl4‐isoxazole propionate receptor subunits (GluRl, GluR2 and GluR3
{designated as GluR2/3}, and GluR4); kainate receptor subunits (GluR6 and
GluR7,{Idesignated as GluR6/7}), and a metabotropic receptor (mGluRlα). The results
indicate that these glutamate receptors are distributed differentially throughout the monkey …
Abstract
To determine the distributions of glutamate receptors throughout the macaque hypothalamus, we utilized highly specific antipeptide antibodies to visualize α‐amino‐3‐hydroxy‐5‐methyl4‐isoxazole propionate receptor subunits (GluRl, GluR2 and GluR3 {designated as GluR2/3}, and GluR4); kainate receptor subunits (GluR6 and GluR7, {Idesignated as GluR6/7}), and a metabotropic receptor (mGluRlα). The results indicate that these glutamate receptors are distributed differentially throughout the monkey hypothalamus. α‐Amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionate receptors are the dominant non‐N‐methyl‐D‐aspartate glutamate receptors within the monkey hypothalamus, and the GluR2 subunit is most abundant. GluR1‐immunoreactive neurons and neuropil are observed predominantly in the tuberal and mammillary nuclei. GluR2/3‐immunoreactive neurons and neuropil have a broader distribution within preoptic, anterior, tuberal, and caudal regions. Separate (but partially overlapping) distributions of GluRl‐ and GluR2/3‐immunoreactive neurons were found, suggesting that the GluR1, GluR2, and/or GluR3 subunits may be coexpressed in subsets of hypothalamic neurons. In contrast, GluR4 immunoreactivity was expressed minimally within monkey hypothalamus. GluR6/7 immunoreactivity was enriched selectively within the suprachiasmatic nucleus. mGluRlα immunoreactivity was present in the mammillary complex. The localization of non‐N‐methyl‐D‐aspartate glutamate receptor subunits to neurons throughout the macaque hypothalamus provides further evidence for the glutamatergic regulation of neuroendocrine, autonomic, and limbic circuits. Differential distributions of glutaniate receptor subunits may increase the dynamic range of the effects of presynaptic glutamate, allowing for the regulation of several distinct functions subserved by hypothalamic neurons. © 1995 Wiley‐Liss, Inc.
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