Adrenergic α2C-receptors reside in rat striatal gabaergic projection neurons:: Comparison of radioligand binding and immunohistochemistry
Adrenergic α2C-receptors reside in rat striatal gabaergic projection neurons:: Comparison of radioligand binding and immunohistochemistry
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DOI：
10.1016/s0306-4522(99)00260-2
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发表时间：
1999-01-01
期刊：
影响因子：
3.3
通讯作者：
Miettinen, R
中科院分区：
文献类型：
--
作者：
Holmberg, M;Scheinin, M;Miettinen, R
我们研究了α（2C）-肾上腺素能受体在大鼠纹状体的分布，并表征了表达这些受体的纹状体神经元类型。用抗大鼠α（2C）-肾上腺素受体的多克隆抗体和抗GABA、钙结合蛋白-D-28 k、小清蛋白和钙视网膜蛋白的抗体进行连续双标记免疫细胞化学。次区域分布的α（2C）-肾上腺素受体结合位点在纹状体也进行了定量研究，使用选择性放射性配体。几乎所有浅染的纹状体GABA能神经元，具有中等大小的棘状投射神经元的形态特征（计数的GABA能细胞的94%），含有α（2C）-肾上腺素受体免疫反应性结构。强标记的GABA能中间神经元（6%）缺乏α（2C）-肾上腺素受体免疫反应性。钙结合蛋白和α（2C）-肾上腺素受体免疫反应性在大多数细胞中的共定位证实了α（2C）-肾上腺素受体在中型多刺神经元群体中的存在。此外，α（2C）-肾上腺素受体/钙结合蛋白双标记揭示了纹状体基质隔室中存在三个神经元亚群：大部分（83%）的双标记神经元，仅表现出α（2C）-肾上腺素受体免疫反应性而无钙结合蛋白免疫反应性的神经元群体（8%），以及钙结合蛋白免疫反应性的神经元群体（9%），但缺乏α（2C）肾上腺素受体。此外，在不含钙结合蛋白的纹状体斑块中观察到α（2C）-肾上腺素受体免疫标记神经元。小白蛋白和钙视黄蛋白阳性神经元从未显示α（2C）-肾上腺素受体免疫反应性，证实纹状体GABA能中间神经元缺乏α（2C）-肾上腺素受体。本研究结果表明，α（2C）-肾上腺素受体定位于GABA能中型棘状投射神经元，但不在大鼠纹状体的中间神经元中，并且它们可能调节基底节的直接和间接通路，以及参与中脑多巴胺能神经元的调节。(C)1999年IBRO。出版社：Elsevier Science Ltd
We have investigated the distribution of alpha(2C)-adrenergic receptors in the rat striatum and characterized the striatal neuron types expressing these receptors. Sequential double-labelled immunocytochemistry was performed with a polyclonal antibody against rat alpha(2C)-adrenoceptors and antibodies against GABA, Calbindin-D-28k, parvalbumin and calretinin. The subregional distribution of alpha(2C)-adrenoceptor binding sites in the striatum was also quantitatively investigated using selective radioligands. Almost all lightly stained striatal GABAergic neurons, with the morphological characteristics of medium-sized spiny projection neurons (94% of GABAergic cells counted), contained alpha(2C)-adrenoceptor-immunoreactive structures. Intensely labelled GABAergic interneurons (6%) were devoid of alpha(2C)-adrenoceptor immunoreactivity. The co-localization of calbindin- and alpha(2C)-adrenoceptor immunoreactivity in the majority of the cells confirmed the presence of alpha(2C)-adrenoceptors in the population of medium-sized spiny neurons. Furthermore, the alpha(2C)-adrenoceptor/calbindin double-labelling disclosed the existence of three neuronal subsets in the matrix compartment of the striatum: a large proportion (83%) of double-labelled neurons, a population of neurons (8%) that exhibited only alpha(2C)-adrenoceptor immunoreactivity without calbindin immunoreactivity, and a population of neurons (9%) immunoreactive for calbindin, but lacking alpha(2C)-adrenoceptors. In addition, alpha(2C)-adrenoceptor immunolabelled neurons were observed in calbindin-free striatal patches. Parvalbumin- and calretinin-positive neurons never displayed alpha(2C)-adrenoceptor immunoreactivity, confirming that striatal GABAergic interneurons are devoid of alpha(2C)-adrenoceptors.The present findings indicate that alpha(2C)-adrenoceptors are localized in GABAergic medium-sized spiny projection neurons but not in interneurons of the rat striatum, and that they may modulate both the direct and indirect pathways of the basal ganglia, as well as participate in the regulation of mesencephalic dopaminergic neurons. (C) 1999 IBRO. Published by Elsevier Science Ltd.