Ragnar Arthur Granit Biography (1900-1991)

Nationality
Finnish
Gender
Male
Occupation
neurophysiologist

Ragnar Arthur Granit was born in Helsinki, Finland, on October 30, 1900, theeldest son of Arthur W. Granit, a government forester, and Albertina Helena Malmberg Granit. Since both his parents were of Swedish origin, Granit attended the Swedish Normal School there. In 1918, Granit fought in Finland's war for independence from the Soviet Union, for which he received the Finnish Crossof Freedom.

The following year Granit entered the University of Helsinki with the intention of studying experimental psychology. However, he decided that a medical education would provide the best foundation for this field. So he went on to complete a master's degree in 1923 and then an M.D. in 1927. It was while completing his medical studies that Granit became interested in studying the nervous system, particularly the eye. The English physiologist EdgarDouglas Adrian had just made the first recordings of electrical impulses insingle nerve fibers, and Granit realized that Adrian's technique could be used to provide useful information about the nervous system as well as the retina. Thus, in 1928 Granit traveled to Oxford University to work with Adrian andanother English physiologist, Charles Scott Sherrington, and learn the techniques of neurophysiology. Soon thereafter, Granit accepted a fellowship in medical physics at the University of Pennsylvania. It was here, while working at the university's Johnson Foundation for Medical Physics, that Granit firstmet Haldan Keffer Hartline, who along with George Wald would eventually sharethe Nobel Prize with Granit.

In 1935 Granit returned to the University of Helsinki as a professor of physiology, but he also continued his research into neurophysics. At this time, itwas still unclear whether light could inhibit, as well as elicit, impulses in the optic nerve. During the early 1930s, Granit produced the first experimental evidence of this inhibition, a finding that remains fundamental to visual physiology. In early work, Granit employed such indirect measures as the sensitivity reported by human subjects to flickering lights. He showed that illumination focused on the retina would suppress the response of adjacent regions. This served to enhance the perception of visual contrasts. Granit soon confirmed these findings using an electroretinogram, a graphic record of electrical activity in the retina, similar to the record of heart activity known asan electrocardiogram.

The 1939 invasion of Finland by the Soviet Union interrupted Granit's work. During the war Granit served as a physician on three Swedish-speaking islands,including Korpo in the Baltic Sea. After the war, he was offered positions at both Harvard University in the United States as well as the Karolinksa Institute in Stockholm. He chose the latter, where he directed the Nobel Institute for Neurophysiology until his retirement in 1967.

While working at the Nobel Institute, Granit and his colleagues became the first scientists to use microelectrodes, tiny electrical conductors, for sensory research. By using microelectrodes to study individual cells in the retina,Granit now demonstrated that certain cells, called modulators, are color-specific, while others, called dominators, respond to a broad range of the spectrum. Although subsequent research has modified his views, Granit's studies were the earliest serious effort to investigate color vision by electrophysiological methods.

Beginning in 1945, Granit shifted the focus of his research to the study of muscle spindles, sensory end organs that are sensitive to muscle tension. Ultimately, the structure of muscle spindles and their function in motor controlbecame one of the best-studied areas in neurophysiology, and Granit was at the forefront of the field. Throughout this period of his career, Granit maintained a hands-on presence in the laboratory and continued to take part in experimental operations on animals there. The procedures he most enjoyed performing were the meticulous dissection of nerves and the careful preparation of nerve roots for electrode placement.

Granit's dual contributions to neurophysiology were honored on numerous occasions. In addition to the Nobel he was awarded such prizes as the 1947 JubileeMedal of the Swedish Society of Physicians, the 1957 Anders Retzius Gold Medal of the University of Utrecht, and the 1961 Jahre Prize of Oslo University.He was once president of the Royal Swedish Academy of Sciences, and a memberof such learned societies as the American Academy of Arts and Sciences, theAmerican National Academy of Sciences, and the Royal Society of London. Active even after his retirement, Granit was appointed a resident scholar at the Fogarty International Center in Bethesda, Maryland, during part of the 1970s.He also accepted a visiting professorship at St. Catherine's College in Oxford, England.

Granit had married Baroness Marguerite Emma "Daisy" Bruun on October 2, 1929,just before leaving for the Johnson Foundation fellowship in the United States. They had one son, Michael, who became a Stockholm architect. Granit diedof a heart attack at his home in Stockholm on March 12, 1991.

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