When we think about the history of glial cells, Santiago Ramón y Cajal comes to mind, who in addition to receiving the Nobel Prize in 1906 for staining individual neurons, is also credited with being the first to be able to specifically stain astroglia (Cajal, 1913a). However, Cajal (1913b) was initially unable to stain a third set of small cells present in tissue sections which apparently did not possess any processes, and which he referred to as the “third element”. Pío del Río-Hortega (Figure 1), originally from Valladolid, Spain, where he graduated in Fine Arts and then received a medical degree, moved to Madrid in 1912 to work with Nicolas Achúcarro from whom he learned various metal impregnation methods for staining tissues and cells (Tremblay et al., 2015). During that period, by modifying the original Golgi staining method to include silver carbonate, he was able to visualize the cells comprising the third element, namely, microglia and oligodendrocytes (Figure 2) for which he correctly deduced their functions of phagocytosis and myelin production, respectively (Río-Hortega, 1919, 1921).

中文翻译：

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神经科学史 I. Pío del Río-Hortega (1882–1945)：小胶质细胞和少突胶质细胞的发现者

当我们思考神经胶质细胞的历史时，我们会想到圣地亚哥·拉蒙·卡哈尔 (Santiago Ramón y Cajal)，他除了因对单个神经元进行染色而于 1906 年获得诺贝尔奖外，还被认为是第一个能够对星形胶质细胞进行特异性染色的人（Cajal， 1913a）。然而，Cajal (1913b) 最初无法对组织切片中存在的第三组小细胞进行染色，这些细胞显然不具有任何突起，他将其称为“第三元素”。Pío del Río-Hortega（图1 ）），最初来自西班牙巴利亚多利德，在那里他毕业于美术专业，然后获得医学学位，1912 年搬到马德里与尼古拉斯·阿丘卡罗 (Nicolas Achúcarro) 一起工作，从他那里他学到了各种金属浸渍方法来对组织和细胞进行染色（Tremblay 等人， 2015）。在此期间，通过修改原来的高尔基体染色方法，加入碳酸银，他能够观察到包含第三种元素的细胞，即小胶质细胞和少突胶质细胞（图2 ））为此，他分别正确地推导了它们的吞噬作用和髓磷脂生成功能（Río-Hortega，1919、1921）。