History of Neuroscience I. Pío del Río-Hortega (1882–1945): The Discoverer of Microglia and Oligodendroglia

摘要

When we think about the history of glial cells, Santiago Ramon y Cajal comes to mind, who in addition to receiv- ing 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”. P ?o del R ?o-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 Achucarro 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 (R ?oHortega, 1919, 1921).