Open main menu

Pío del Río Hortega (1882 – 1945) was a Spanish neuroscientist who discovered microglia.

Pío del Río Hortega
Estatua Pío del Río Hortega Museo Ciencia (Valladolid), detalle.JPG
Pío del Río Hortega outside Valladolid Science Museum
Born5 May 1882
Died1 June 1945 (aged 63)
Known fordiscovering microglia


Río Hortega was born in Portillo, Valladolid on 5 May 1882.[1] He studied locally and qualified to practice medicine in 1905. He obtained his doctorate at the University of Madrid by researching the pathology of brain tumours. In 1913 he was funded to study research histology in France and Germany but the outbreak of war between them forced him to return to Spain.[1]

He worked with the histologist Santiago Ramón y Cajal and briefly with Wilder Penfield. Ramón y Cajal discovered neurons, Penfield helped explain oligodendroglia.[2] whilst Rio Hortega discovered microglia.[3] which are the cells that protect the brain from infection.

He managed to identify microglia between 1919 and 1921 by staining the cells with silver carbonate.[3] His method of staining also led to the discovery of oligodendroglia in 1921, which both he and Penfield are now credited with.[2] However it was Rio Hortega who named the cells.[1]

His discoveries in 1920 created issues with Ramón y Cajal, who led the lab, as he had earlier won the Nobel prize. By 1931 del Río Hortega was leading Spain's cancer institute, but he left the country when the civil war broke out in 1936.[1]

War spreading across Europe found him in Paris at the Pitié-Salpêtrière Hospital before he went to the University of Oxford to work with the British neurosurgeon Hugh Cairns.[4] The bombing of Britain by Germany in World War II drove him on to Argentina. His escape was funded by the Spanish Cultural Institute, who continued to support him as he created his own laboratory in 1942. Río Hortega died in Buenos Aires on 1 June 1945 from a malignant neoplasm.[1]


  1. ^ a b c d e "Historical perspective on oligodendrocytes and myelin". University of Illinois at Chicago. Retrieved 18 December 2012.
  2. ^ a b Gill, AS; DK Binder (May 2007). "Wilder Penfield, Pío del Río-Hortega, and the discovery of oligodendroglia". Neurosurgery. 60 (5): discussion 940–8. doi:10.1227/01.NEU.0000255448.97730.34. PMID 17460531.
  3. ^ a b "Pio del Rio Hortega". Encyclopædia Britannica. Retrieved 18 December 2012.
  4. ^ "Pio_del_Rio-Hortega (translation)". Retrieved 18 December 2012.