Ginsberg S D, Price D L, Blackstone C D, Huganir R L, Martin L J
Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA.
J Comp Neurol. 1995 Mar 20;353(4):539-52. doi: 10.1002/cne.903530406.
To determine the distributions of glutamate receptors throughout the macaque hypothalamus, we utilized highly specific antipeptide antibodies to visualize alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subunits (GluR1, GluR2 and GluR3 [designated as GluR2/3], and GluR4); kainate receptor subunits (GluR6 and GluR7, [designated as GluR6/7]), and a metabotropic receptor (mGluR1 alpha). The results indicate that these glutamate receptors are distributed differentially throughout the monkey hypothalamus. alpha-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 GluR1- 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. mGluR1 alpha 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 glutamate 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.
为了确定猕猴下丘脑内谷氨酸受体的分布情况，我们使用了高度特异性的抗肽抗体来可视化α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体亚基（GluR1、GluR2和GluR3[命名为GluR2/3]以及GluR4）；海人藻酸受体亚基（GluR6和GluR7，[命名为GluR6/7]）以及一种代谢型受体（mGluR1α）。结果表明，这些谷氨酸受体在猴下丘脑内的分布存在差异。α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体是猴下丘脑内主要的非N-甲基-D-天冬氨酸谷氨酸受体，其中GluR2亚基最为丰富。GluR1免疫反应性神经元和神经纤维主要见于结节核和乳头体核。GluR2/3免疫反应性神经元和神经纤维在视前区、前部、结节区和尾部区域有更广泛的分布。发现了GluR1和GluR2/3免疫反应性神经元的单独（但部分重叠）分布，这表明GluR1、GluR2和/或GluR3亚基可能在下丘脑神经元亚群中共表达。相比之下，GluR4免疫反应性在猴下丘脑内的表达极少。GluR6/7免疫反应性在视交叉上核中选择性富集。mGluR1α免疫反应性存在于乳头体复合体中。猕猴下丘脑内非N-甲基-D-天冬氨酸谷氨酸受体亚基在神经元中的定位为神经内分泌、自主神经和边缘系统回路的谷氨酸能调节提供了进一步的证据。谷氨酸受体亚基的差异分布可能会增加突触前谷氨酸作用的动态范围，从而调节下丘脑神经元所承担的几种不同功能。
