Wang Hong-Bing, Deng Yun-Ping, Reiner Anton
Department of Anatomy & Neurobiology, College of Medicine, The University of Tennessee Health Science Center, 855 Monroe Ave., Memphis, TN 38163, United States.
Neurosci Lett. 2007 Oct 2;425(3):195-9. doi: 10.1016/j.neulet.2007.08.033. Epub 2007 Aug 22.
In a prior study, we showed that the few striatal projection neurons that contain both substance P (SP) and enkephalin (ENK) in rats may preferentially project to the substantia nigra pars compacta. Since striatal neurons that project to the pars compacta are thought to preferentially reside in the striosomal compartment, we investigated if striatal neurons that contain both SP and ENK are preferentially localized to the patch compartment. We used in situ hybridization histochemistry to double-label sections for SP and ENK to identify SP/ENK co-containing neurons, and immunolabeling of adjacent sections for the mu opiate receptor (MOR) to define the striosomal compartment. We found that 32.3% of neurons containing both SP and ENK were localized to the striosomal compartment, which itself only made up 12.8% of the striatum. Our results further showed that the density of neurons co-containing SP and ENK was three-fold higher in striosomes than in the matrix compartment. These results are consistent with the notion that SP/ENK colocalizing neurons preferentially project to pars compacta, and these and our prior results additionally raise the possibility that neurons of this type in the striatal matrix may also project to the pars compacta.
在之前的一项研究中，我们发现，大鼠中少数同时含有P物质（SP）和脑啡肽（ENK）的纹状体投射神经元可能优先投射至黑质致密部。由于投射至致密部的纹状体神经元被认为优先位于纹状体内，我们研究了同时含有SP和ENK的纹状体神经元是否优先定位于纹状体小块区。我们采用原位杂交组织化学方法对SP和ENK进行双重标记切片，以识别同时含有SP和ENK的神经元，并对相邻切片进行μ阿片受体（MOR）免疫标记以界定纹状体小块区。我们发现，同时含有SP和ENK的神经元中有32.3%定位于纹状体小块区，而纹状体小块区本身仅占纹状体的12.8%。我们的结果进一步表明，纹状体内同时含有SP和ENK的神经元密度比基质区高两倍。这些结果与SP/ENK共定位神经元优先投射至致密部的观点一致，并且这些结果以及我们之前的结果还增加了一种可能性，即纹状体基质中这种类型的神经元也可能投射至致密部。
