Freed C, Revay R, Vaughan R A, Kriek E, Grant S, Uhl G R, Kuhar M J
Molecular Neurobiology Branch, National Institutes on Drug Abuse, Baltimore, MD 21224, USA.
J Comp Neurol. 1995 Aug 21;359(2):340-9. doi: 10.1002/cne.903590211.
The dopamine transporter (DAT) is a primary site for the action of cocaine in inducing euphoria. Its action is necessary for the selectivities of dopaminergic neurotoxins that provide the best current experimental models of Parkinson's disease. In the present report, rat dopamine transporter-like immunoreactivity (iDAT) was assessed by immunohistochemistry using newly developed polyclonal antisera raised against conjugated peptides corresponding to sequences found in the dopamine transporter's carboxy- and amino-termini. Dense iDAT was observed in patterns consistent with neural processes and terminals in the striatum, nucleus accumbens, olfactory tubercle, nigrostriatal bundle, and lateral habenula. Perikarya in the substantia nigra pars compacta were immunostained with moderate intensity using one of two immunohistochemical methods, while scattered ventral tegmental area perikarya were stained with somewhat less intensity. Immunoreactive neuronal processes with axonal and dendritic morphologies were stained in the substantia nigra and the paranigral and parabrachialis pigmentosus nuclei of the ventral tegmental area, while sparser processes were noted more medially in the ventral tegmental area. Neuronal processes were found in several laminae in the cingulate cortex, with notable fiber densities in the superficial aspects of lamina I and laminae II/III. The intensities of immunoreactivities in striatum and cerebral cortex were dramatically attenuated ipsilateral to nigrostriatal bundle 6-hydroxydopamine lesions. Specificity of immunostaining was supported by agreement of the results using sera directed against two distinct DAT segments, studies with preimmune and preadsorbed sera and studies of the extracted protein. These antisera identify and reveal details of the distribution of DAT immunoreactivity in rat brain and display variations in levels of DAT expression of likely functional significance.
多巴胺转运体（DAT）是可卡因诱发欣快感作用的主要位点。其作用对于多巴胺能神经毒素的选择性而言是必需的，这些神经毒素提供了目前帕金森病的最佳实验模型。在本报告中，通过免疫组织化学方法，使用针对与多巴胺转运体羧基末端和氨基末端序列相对应的偶联肽产生的新开发多克隆抗血清，评估大鼠多巴胺转运体样免疫反应性（iDAT）。在纹状体、伏隔核、嗅结节、黑质纹状体束和外侧缰核中观察到密集的iDAT，其模式与神经突起和终末一致。使用两种免疫组织化学方法之一，黑质致密部的神经元胞体呈中等强度免疫染色，而腹侧被盖区散在的神经元胞体染色强度稍低。在黑质以及腹侧被盖区的旁黑质和臂旁色素核中，具有轴突和树突形态的免疫反应性神经突起被染色，而在腹侧被盖区更内侧观察到的神经突起较少。在扣带回皮质的几个层中发现了神经突起，在I层和II/III层的浅层有明显的纤维密度。在黑质纹状体束6-羟基多巴胺损伤同侧的纹状体和大脑皮质中，免疫反应强度显著减弱。使用针对两个不同DAT片段的血清所获得的结果一致，以及用免疫前血清和吸附血清进行的研究以及对提取蛋白的研究，均支持免疫染色的特异性。这些抗血清识别并揭示了大鼠脑中DAT免疫反应性分布的细节，并显示出可能具有功能意义的DAT表达水平的变化。
