Santiago Ramón y Cajal
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Author: Mr. Abdellatif Nemri, Department of biological sciences, University of Montreal, Canada
--- WORK IN PROGRESS ---
Santiago Ramón y Cajal (May 1, 1852 – October 17, 1934) was a Spanish physician and scientist who is considered the founder of modern neurobiology. His masterful use of the staining technique invented by Camillo Golgi, an Italian physician and scientist from the University of Pavia, allowed him to be the first to report with precision the fine anatomy of the nervous system. His work was central in the elaboration of the Neuron Doctrine. Cajal demonstrated that the nervous system was made up of individual cells connected to each other by small contact zones (synapses, term coined by Sherrington). Each cell had 3 compartments, the cell body or soma, the axon and the dendritic arborization. He also proposed that neurons (the term was coined by Waldeyer) were polarized, that is, nervous impulses propagated invariably from dendrites to the soma to the axon.
Cajal shared the Nobel Prize in Physiology or Medicine in 1906 with Golgi in recognition of their work on the structure of the nervous system.
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Early years
Cajal was born in May 1952 in Petilla de Aragón, northeast Spain, where his father was the village surgeon. As a teenager, his father apprenticed him to a barber and to a cobbler. However, Cajal’s inclination was for the arts, especially drawing. His father who was appointed Professor of Applied Anatomy at the University of Saragossa finally convinced him to study medicine. Cajal graduated in 1873 and shortly after was drafted into the army. He served as an army physician in Cuba, under Spanish rule at that time, and contracted malaria and tuberculosis during the expedition (1874-1875). After his return to Spain, Cajal started his academic career in the end of 1975 as an assistant in the School of Anatomy at the University of Saragossa. In 1879 Cajal married Silvería Fañanás García. They had four daughters and three sons.
Academic career
On his return from Cuba Cajal became an assistant in the School of Anatomy in the Faculty of Medicine at the University of Saragossa (1875). Two years later he obtained the degree of Doctor of Medicine at Madrid. At his own request, Cajal became Director of the Saragossa Museum (1879), and in 1883 he was appointed Professor of Descriptive and General Anatomy at Valencia. In 1887 he was appointed Professor of Histology and Pathological Anatomy at Barcelona and in 1892 he was appointed to the same Chair at Madrid. In 1900-1901 he was appointed Director of the National Institute of Hygiene and Biological Investigations. Cajal continued to work productively in Madrid until his death in 1934.
Distinctions
Election to learned societies and academies: Member of the Royal Academy of Sciences of Madrid (1895); of the Royal Academy of Medicine of Madrid (1897); of the Spanish Society of Natural History and of the Academy of Sciences of Lisbon (1897); Honorary Member of the Spanish Medical and Surgical Academy and also of several other Spanish societies; Associate Member of the Academy of Medicine, Paris (1906); member of the Swedish Academy of Sciences (1916).
Honorary degrees: Doctorate of Medicine from the Universities of Cambridge (1894) and Würzburg (1896) and Doctorate of Philosophy from the Clark University (Worcester, U.S.A., 1899).
Prizes. Among the prizes won by Cajal are the following: the Rubio Prize of 1,000 pesetas for his previously mentioned Elementos de Histología, etc., the Fauvelle Prize of 1,500 francs of the Society of Biology of Paris (1896); the Moscow Prize of 5,000 francs, established by the Congress of Moscow (1897) to reward medical works which, published during the latter three years, have rendered the greatest services to science and humanity was awarded to Ramon y Cajàl by the International Congress of Medicine in Paris (1900).
In 1905, the Royal Academy of Sciences of Berlin awarded him the Helmholtz Medal.
In 1906, Cajal shared the Nobel Prize in physiology or medicine with Camillo Golgi.
Scientific contributions
‘’The facts remain and theories pass away” Santiago Ramón y Cajal, 1894
"I [...] was led to a conciliatory or compromising solution, erroneous, as are almost all intermediate opinions in science." Ramón y Cajal, Recollections
Anatomy before Cajal
During the 19th century, the cell theory became progressively accepted for all tissues except the nervous system.
cell theory = ...
Technical limitations in association with the complexity of the nervous tissue made its anatomical characterization difficult. The prevalent view at that time was that the nervous system was organized in a reticular way (nerve fibers forming an anatomically connected network). Some authors argued that cell theory should apply to the nervous system as well, but their claims were more intuition based than evidence based.
Cajal : 1987-1992
Young Cajal was like most a reticularist when he started conducting research.
Golgi staining technique
...
The neuronal doctrine had four tenets:
- The neuron is the structural and functional unit of the nervous system
- Neurons are individual cells, which are not anatomically continuous to other neurons
- The neuron has three parts: dendrites, soma (cell body) and axon. The axon has several terminal arborizations, which make close contact to dendrites or the soma of other neurons
- Conduction takes place in the direction from dendrites to soma, to the end arborizations of the axon (Law of Dynamic Polarization)
Cajal discovered characteristic structures in dendrites, which he called spines because of their appearance. http://www.cerebromente.org.br/n17/history/neurons3_i.htm
| 1836 | First microscopic image of a nerve cell (Valentin) |
| 1862 | First description of the neuromuscular junction (Kühne) |
| 1873 | Introduction of silver-chromate technique as staining procedure (Golgi) |
| 1888 | Birth of the neuron doctrine: the nervous system is made up of independent cells (Cajal) |
| 1891 | The term “neuron” is coined (Waldeyer). |
| 1892 | Laws of dynamic polarization of neurons (Cajal) |
| 1897 | Concept of synapse (Sherrington) |
| 1903 | Introduction of silver nitrate as staining technique (Cajal) |
| 1904 | Textura del Sistema Nervioso del Hombre y de los Vertebrados: coming-of-age of the neuron theory (Cajal) |
Cajal Legacy
/Complete list of published works
Santiago Ramón y Cajal died in Madrid on October 18, 1934. He gave all his belongings to the institute he founded in Madrid. Originally named Laboratorio de Investigaciones Biológicas, and founded in 1900 by order of King Alfonso XII on the occasion of the Moscow Prize to Cajal, the institute was renamed after him in 1932 (Instituto Cajal, Madrid). The collection of his works and other items, including thousands of scientific drawings and illustrations, histological preparations, books, publications, letters, photographs and microscopes is known today as the Cajal Legacy.
At least one other institution was named after Cajal: the Cajal Neuroscience Research Center (CNRC) at the University of Texas at San Antonio http://utsa.edu/crts/rcmi/about.htm
The Cajal club (founded 1947) is an organization of neuroscientists whose goals are to 1) revere Cajal, 2) provide an opportunity for neuroscientists with special interests in the structure and function of the nervous system to confraternize, and 3) contribute to the welfare of neuroanatomy and neuroanatomists.
Petilla Interneuron Nomenclature Group (PinG) proposes a standardized nomenclature of interneuron properties. This proposal arose out of a meeting devoted to this topic in Cajal's native town, Petilla de Aragón (Navarra, Spain), and is rooted in the collective work that has been performed in many laboratories (PinG consists of 39 prominent neuroscientists). Nature Reviews Neuroscience 9, 557-568
The asteroid ‘’117413 Ramonycajal’’, discovered by Juan Lacruz in 2005, was named in his honour by the Minor Planet Center, the institution responsible for the designation of minor bodies in the solar system (http://www.cfa.harvard.edu/iau/mpc.html).
References
- De Carlos, J.A. & Borrel, J. (2007). A historical reflection of the contributions of Cajal and Golgi to the foundations of neuroscience. Brain Res Rev, 55: 8-16.
- Lopez-Munoz, F., Boya, J., Alamo, C. (2006). Neuron theory, the cornerstone of neuroscience, on the centenary of the Nobel Prize award to Santiago Ramon y Cajal. Brain Res Bull, 70: 391-405.
- Waldeyer, W. (1891). Über einige neuere Forschungen im Gebiete der Anatomie des centralen Nervensystems. Deutsch Med Wochenschr, 17, 1213–1218, 1244–1246; 1267–1269; 1331–1332; 1352–1356.
Further reading
- Cajal's autobiography: Recollections of my life, MIT Press
External links
- Cajal Institute (Madrid) Largest neuroscience research center in Spain.
- Nobelprize.org: Cajal's Nobel lecture: The Structure and Connexions of Neurons
- Nobelprize.org: biography and life and discoveries
- Nobelprize.org: About the shared Nobel prize between Cajal and Golgi
- Wikipedia: Neuron doctrine, Heinrich Wilhelm Waldeyer, Neuron
See also
Camillo Golgi, Brain, Neuron, Neuron doctrine, Neuroscience,
| Invited by: | Dr. Eugene M. Izhikevich, Editor-in-Chief of Scholarpedia, the peer-reviewed open-access encyclopedia |
