Background

Pío del Río Hortega was born on May 5, 1882, in Portillo, Valladolid, Spain.

Education

Rio-Hortega received his medical degree in 1905 from the University of Valladolid. He obtained his doctorate at the University of Madrid by researching the pathology of brain tumours.

Career

After receiving his medical degree in 1905 from the University of Valladolid, Rio-Hortega became an assistant professor of histology. In 1915, after two years of study in Paris and London, he returned to Madrid and joined the laboratory staff of Nicolas Achucarro, the histologist known for his studies of neuroglia and whose team worked closely with that of Santiago Ramon y Cajal.

Between 1914 and 1916 Rio-Hortega worked on various histological topics, including the structure of the ovary and the fine texture of cancer cells. He did not begin his major work on the insterstitial cells of the nervous system until 1916. Both Ramon y Cajal and Achucarro had studied the cytology of neurons and astrocytes, but the nature of the cells that the former called “corpuscles without processes” or the “third element” remained unclear.

By 1918 Rio-Hortega had developed a silver carbonate stain enabling him to explicate the fine structure of the “third element,” which he found to consist of two different cytological types; microglia, small cells of mesodermal origin with spiny processes, dispersed throughout the central nervous system; and interfascicular glia or oligodendroglia, cells of ectodermal origin that follow and surround the nerve fibers. Rio-Hortega’s demonstration that these cells do not lack processes - as Ramon y Cajal had thought - led to heated controversy that strained relations between the two researchers.

The next phase of Rio-Hortega’s career unfolded at the National Institute of Cancer in Madrid, where he headed the research division from 1928 to 1936. There he produced the basic cytological descriptions necessary for the classification of gliomatous and other tumors of the central nervous system. Soon after the outbreak of the Spanish Civil War, he left Spain to work in neuropathology laboratories in Paris and Oxford. In 1940 he removed to Argentina. There he organized a laboratory in Buenos Aires and founded the Archivos de Histologia normaly patoldgica, in which he published his last studies on the neuroglial character of the satellite cells surrounding the neurons of sensory ganglia.

Achievements

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  The studies of Doctor Pío del Río Hortega have been the most exhaustive histology and cytology-based studies of nervous system tumors. One of Hortega's major achievements was in his revolutionary study in the area of neuroglia that culminated in the development and improvement of metallic impregnation techniques that he applied to the study of the group of non-astrocytic cells. These cells were poorly stained with the methods available at that time, and were known after Ramón y Cajal as the “third element” of Central Nervous System (CNS), neurons and astrocytes being the “first and second element”. By developing the innovative staining tools, Del Río Hortega was able to identify two kinds of cells and to unveil their origin: microglia, the true “third element” due to its mesodermic origin, and oligodendroglia, included with astrocytes as the second element due to their shared ectodermal origin
  
  Also, from his lab in Buenos Aires, Río Hortega made yet another important contribution: demonstrate the character neuroglico of satellite cells surrounding neurons and sensory ganglia of the vegetative nervous system. The comparability of these gliocitos to the oligodendroglia was the culmination of his work on the nervous glia.
  
  

Works

More photos

• book

  • El maestro y yo

    ( )

  • The Microscopic Anatomy of Tumors of the Central and Peripheral Nervous System 1962

Views

Even as a medical student, Pío del Río Hortega committed himself to follow a career in research which was focused on neurohistology and pathology all his professional life.

Quotations: "Histology is an exotic meal, but can be as repulsive as a dose of medicine for students who are obliged to study it, and little loved by doctors who have finished their study of it all too hastily. Taken compulsorily in large doses it is impossible to digest, but after repeated tastings in small draughts it becomes completely agreeable and even addictive. Whoever possesses a refined sensitivity for artistic manifestations will appreciate that, in the science of histology, there exists an inherent focus of aesthetic emotions."

Connections

colleague:

Wilder Penfield

colleague:

Santiago y Cajal

Cajal discovered neurons, Penfield helped explain oligodendroglia, whilst Rio Hortega discovered microglia, which are the cells that protect the brain from infection.

In 1914, Río Hortega had the opportunity to share scientific interests with Ramón y Cajal, to whom he always felt great admiration, since Cajal’s and Achúcarro’s laboratories were located in the same building though each did independent research.

mentor:

Nicolás Achúcarro y Lund

Río Hortega started his postdoctoral training in Nicolás Achúcarro’s laboratory in Madrid (Spain) in 1912. Achúcarro was Del Río Hortega’s true mentor and inculcated in him a deep interest in neuroglia before he worked in several European laboratories for short periods.

References

• Dictionary of Scientific Biography Volume 11
  1975
• Una contribución a la ciencia histológica: La obra de don Pío del Río-Hortega
  1985
• La histología aragonesa en América: descubrimientos y vanguardia : Pío del Río
  1990
• Pío del Río Hortega
  1990
• Espistolario y otros documentos inéditos
  1993