Haug F M
J Hirnforsch. 1975;16(2):151-62.
Timm's sulphide silver method is generally regarded as a sensitive histochemical method for transition metals, group 2b metals, and heavy metals. It has been used frequently both for investigating the localization of metals normally present in various tissues and, in animal experiments, for tracing the distribution of metals administered in toxic amounts. The present author has standardized the method to ensure a reproducible, strong, sulphide silver staining in the central nervous system of the rat, and made the following light microscopic findings, briefly summarized: 1) White matter is only very lightly stainable, some of this stain clearly being confined to glial perikarya and processes. 2) The staining of glia (in white and grey matter) is differentiated both according to region and type of cell. 3) The latter is also true for neuronal somata. 4) Within the neuropil there are sharp borders as well as diffuse gradients with respect ot staining density. Most of the stain is confined to granules about the size of synaptic boutons. The staining of neuropil in the cerebral cortex has received special emphasis: It is stronger than in most other regions and its exquisite laminar distribution faithfully reproduces known synaptic fields, suggesting a close association with certain fibre systems or types of synapses. This conclusion is supported by the previous electron microscopic finding of precipitate within the large hippocampal mossy fibre boutons, and by preliminary electron microscopic and experimental data for other laminae and fields within the hippocampus. The histochemical validity of the sulphide silver method has been extensively discussed elsewhere. It seems appropriate to conclude that the staining pattern described light microscopically gives a valid picture of the distribution of one or more, but not all, important transition metal fractions within the brain. The use of intravital chelation for manipulating the stainable metals are discussed. Several basal questions to be answered on the path towards an understanding of their functions are suggested. Thus a solid factual basis should be provided upon which to start a rational search for disturbances of their functions.
蒂姆硫化银法通常被认为是一种用于检测过渡金属、2B族金属和重金属的灵敏组织化学方法。它经常被用于研究正常存在于各种组织中的金属的定位，以及在动物实验中追踪给予毒性剂量的金属的分布。作者对该方法进行了标准化，以确保在大鼠中枢神经系统中获得可重复的、强烈的硫化银染色，并得出以下光镜观察结果，简要总结如下：1）白质仅能被非常轻微地染色，其中一些染色明显局限于神经胶质细胞的胞体和突起。2）神经胶质细胞（在白质和灰质中）的染色根据区域和细胞类型而有所不同。3）神经元胞体也是如此。4）在神经毡内，染色密度存在清晰的边界以及弥散的梯度。大部分染色局限于突触小体大小的颗粒。大脑皮质神经毡的染色受到了特别关注：它比大多数其他区域更强，其精细的分层分布忠实地再现了已知的突触场，表明与某些纤维系统或突触类型密切相关。这一结论得到了先前在大型海马苔藓纤维突触小体内发现沉淀物的电子显微镜观察结果，以及海马其他层和区域的初步电子显微镜和实验数据的支持。硫化银法的组织化学有效性在其他地方已被广泛讨论。似乎可以得出结论，光镜下描述的染色模式给出了大脑中一种或多种但并非所有重要过渡金属组分分布的有效图像。讨论了使用活体螯合来操纵可染色金属的问题。提出了在理解其功能的道路上需要回答的几个基本问题。因此，应该提供一个坚实的事实基础，以便开始对其功能紊乱进行合理的探索。
