Light Microscopy Facility, Max-Planck-Institute of Experimental Medicine Göttingen, Germany.
Front Physiol. 2012 Sep 25;3:372. doi: 10.3389/fphys.2012.00372. eCollection 2012.
Nitric oxide is unconstrained by cell membranes and can therefore act along a broad distance as a volume transmitter. Spillover of nitric oxide between neurons may have a major impact on central nervous system diseases and particularly on neurodegeneration. There is evidence whereby communication between nitrergic and dopaminergic systems plays an essential role in the control of the nigrostriatal pathway. However, there is sparse information for either the coexistence or overlap of nitric oxide and dopaminergic structures. The dual localization of immunoreactivity for nitric oxide synthase (NOS) and tyrosine hydroxylase, enzymes responsible for the synthesis of nitric oxide and dopamine, respectively, was examined in neurons of the nigrostriatal pathway in the rat brain by means of a double-immunohistochemical method and confocal laser scanning microscopy, acquired at the resolution limit. After perfusional fixation, the brains were cut and double-immunostained. A proximity analysis of tyrosine hydroxylase and NOS structures was done using binary masks generated from the respective maximum projections, using confocal laser microscopy. Unrevealed regions were determined somatodendritic positive for both NOS and tyrosine hydroxylase, within an image limit resolution at 2 μm-wide margin. The described interconnected localization of nNOS(+) and TH(+) containing neuronal fibers and cells bodies in the nigrostriatal pathway propose a close anatomical link between the two neurotransmitters.
一氧化氮不受细胞膜的限制，因此可以作为一种容积递质在很大范围内发挥作用。神经元之间一氧化氮的溢出可能对中枢神经系统疾病，特别是神经退行性疾病有重大影响。有证据表明，氮能系统和多巴胺能系统之间的通讯在控制黑质纹状体通路中起着至关重要的作用。然而，对于一氧化氮和多巴胺能结构的共存或重叠，信息仍然很少。通过双重免疫组织化学方法和共聚焦激光扫描显微镜，在大鼠脑的黑质纹状体通路上，在分辨率极限处获得，检查了一氧化氮合酶（NOS）和酪氨酸羟化酶的免疫反应性的双重定位，分别负责一氧化氮和多巴胺的合成。在灌注固定后，大脑被切割并进行双重免疫染色。使用来自各自最大投影的二进制掩模，使用共聚焦激光显微镜对酪氨酸羟化酶和 NOS 结构进行接近分析。在 2μm 宽的图像限制分辨率内，确定了两种 NOS 和酪氨酸羟化酶都在体树突阳性的未揭示区域。黑质纹状体通路上描述的 nNOS(+)和 TH(+)含神经元纤维和细胞体的相互连接定位，提出了两种神经递质之间的紧密解剖联系。
