Localization of glial-cell line derived neurotrophic factor receptor (GFRa1) in the brain

神经胶质细胞系来源的神经营养因子（GDNFR）已被证明对脊髓前角细胞中的多巴胺能神经元和运动神经元具有营养作用。在本研究项目中，我们计划用免疫组化方法定位GDNFR在大脑中的位置，并研究GDNFR是否参与神经退行性疾病如帕金森病、肌萎缩侧索硬化症、多系统萎缩症和阿尔茨海默病的病理生理。我们首次开发了一种针对GDNFR氨基末端合成肽的抗肽抗体，该抗体可识别大鼠脑浆液中分子量为80 kDa的单个蛋白。抗体与免疫原的预吸收完全消除了免疫印迹区免疫染色。免疫组织化学研究表明，gdnfr免疫反应仅在神经元中发生，未见神经胶质细胞免疫阳性。免疫阳性神经元体遍布大鼠脑。在新皮层，阳性神经元分布于第2层至第6层，锥体细胞和非锥体细胞均有标记。基底前脑Meynert核、中间隔核、Broca对角带核和腹侧苍白球核中有大量大细胞被免疫标记。后脑核中也发现大量神经元体，包括黑质、中缝和耳蜗核。因此，GDNF反应神经元在大鼠脑中的分布似乎比先前描述的更广泛。

Glial cell line-derived neurotrophic factor (GDNFR) has been shown to have trophic effect upon dopaminergic neurons and motoneurons in the anterior horn cells of spinal cord. In the present research project we have planned to localize GDNFR in the brain immunohistochemically and examine whether GDNFR is involved in the pathophysiology of neurodegenerative disease such as Parkinson's disease, amyotrophic lateral sclerosis, multiple system atrophy and Alzheimer's disease.We have firstly developed an anti-peptide antibody against synthetic peptide of amino-terminal portion of GDNFR The antibody recognized a single protein of molecular weight of 80 kDa in the rat brain homogenate. The preabsorption of the antibody with the immunogen completely abolished the immunostaining in the western blot lane. The immunohistochemical study has demonstrated GDNFR-immunoreactivity exclusively in neurons and no glial cells were immunopositive. The immunopositive neuronal somata were found throughout the rat brain. In the neocortex the positive neurons were distributed in the layer II through to layer VI.Pyramidal and non-pyramidal cell were both labeled. In the basal forebrain, numerous large sized neurons were immunolabeled in the nucleus of Meynert, medial septal nucleus, nucleus, of diagonal band of Broca and ventral pallidum. Numerous neuronal somata were found also in nuclei of the hind brain, including substantia nigra, raphe, and cochlear nucleus. Thus, GDNF responsive neurons appear to be distributed more widespread in the rat brain than previously described.