Granite (Granit), Ragnar( Swedish neyrofizik Nobel Prize in Physiology or Medicine, 1967)
Comments for Granite (Granit), Ragnar
Biography Granite (Granit), Ragnar
genus. October 30, 1900
Swedish neyrofizik Ragnar Arthur Granit was born in Helsinki (Finland). He was the eldest son of Albertina Helena (Malmberg) Granite and Arthur Granita, an employee of state forest. Shortly after the birth of his son's family opened the case on trade in forest products in Helsinki, where the boy, whose parents were of Swedish origin, visited the Swedish normal school. While still a schoolboy, Mr.. participated in the struggle for the independence of Finland from Russia in 1918. and was awarded the Finnish Cross of Freedom. Enrolling in the next year in the University of Helsinki to study experimental psychology, Mr.. decides to thoroughly deepen their knowledge through the course of medicine. In 1923, Mr.. He received a master's degree, and in 1927. - Medical.
During his studies Mr.. particularly interested in the physiology of vision. Up until the mid 20-ies. the study was conducted of indirect method and based mainly on the study of the relationship between physical properties, such as wavelength or intensity of the light source, and the process of their perception of people. In 1926, Mr.. Edgar D. Adrian first to detect electrical impulses in individual nerve fibers, and then - in the optic nerve conger eel, which represents a bundle of many thousands of nerve fibers. Santiago RamцЁn-Kahal, one of the founders of microscopic neuroanatomy, remarked in 1894 that the retina - the nerve center of this and that it differs from other senses, as a direct continuation of the brain. Italian histologist Camillo Golgi perfected a system of coloring nerve cells with silver nitrate and opened a fine network within the cell, now called 'Golgi apparatus'.
G. realized that a lot of important information about the nervous system in general and vision in particular can be obtained by studying the retina using the method of recording pulses, developed by Adrian. Having set ourselves this task, T. in 1928. went to Oxford University to be able to work not only with Adrian, but also with his mentor, Charles C. Sherrington. The latter belonged to the discovery, namely, that the nerves controlling the muscles of two groups of the femur and tibia, are interconnected in such a way that stimulation causes inhibition of one another. The idea that inhibition processes are important in regulating the activity of nerve cells, induced G. to investigate their possible role in visual function, particularly the retina.
Having mastered the techniques elektroneyrofiziologii, D. spent the next three academic years (1929 ... 1932) in Dzhonsonovskom Institute of Medical Physics, University of Pennsylvania. Continuing his studies in the physiology of vision, he met with X. Keffer Hartlaynom and George Wald, who worked on similar themes. In early experiments, T. use the traditional indirect methods (eg, . studied the sensitivity of the subject's rights to change the world) and found, . that the strong coverage of some sections of the retina inhibits the response in the surrounding areas, . which reinforces the perception of the eye light contrasts,
. (The importance of this lateral inhibition for the processing of visual information was shown Hartlaynom in the study of individual cells, retina, and, much later, David A. David H. Hubel and Torsten Wiesel in their writings on the visual centers of the brain.) T. used elektroretinogrammoy (ERG) - recording the activity of the retina as a whole - to prove that 'the details of the visual image developed under the influence of excitation and inhibition of the nerve center of the retina itself. "
. Many experiments elektroretinograficheskie G
. were performed in the University of Helsinki, where he returned in 1935, he was appointed professor of physiology. However, he became interested in other aspects of vision, particularly color vision.
In XIX. German physicist Ferdinand von Helmholtz and the English scientist Thomas Young suggested, . that the ability of the human eye to distinguish the spectrum of colors can be explained in the case, . if we can prove the existence in the eye of receptors (cones) with pigments, . sensitive to different length of light waves,
. Helmholtz theory of color vision - Yang claimed that in the retina has three types of tsvetovosprinimayuschih elements - for red, green and purple - and the perception of other colors depending on the combined stimulation of these elements. The first experiments in color vision have been implemented G. in 1937. using the ERG to confirm the degree of spectral differentiation.
In 1939, Mr.. during the military conflict between Finland and the Soviet Union, Mr.. served as a doctor at about. Corpo in the Baltic Sea - the home of his ancestors, and its residents enjoy the services of two other Swedish-parishes neighboring islands, and also in the district military personnel. At this time, Mr.. interrupted their studies. After the war, Mr.. received offers from Harvard University and the Karolinska Institute. He chose the latter and in 1940. moved to Stockholm.
In Sweden, Mr.. colleagues developed a method for recording electrical nerve impulses and the individual cells using microscopic electrodes, without resorting to the anatomy. This non-invasive method in the future was widespread in neurophysiological studies of all types. Sam G. used it to study the reaction of the optic nerve - and later the individual cells of the retina - the specific color. He established the existence of three types of cones, sensitive to different colors of the spectrum: blue, green and red. Biochemical evidence in favor of Mr.. received in the 50-ies. George Wald, singled out three cone pigments.
Realizing that 'several monotonous work on registration of the spectral sensitivity of cells in the absence of photochemical data' hinders 'interests to the entire field of research', T. switched in 1945. the study of muscle spindles - specialized sensory organs that respond to muscular tension and providing feedback for the control of muscle response from the organism. Sherrington and John. Eccles had already established the role of spindles in the reflex movements and control of posture. Based on these studies, T. continued to study the function of spindles and the relationships among different groups. Then he expanded the theme of his research, and dealt with the relationship between the muscles, motoneurons and spindle nerves in the spinal cord and brain.
Since 1945, when the Karolinska Institute has reorganized the laboratory G. Department Medical Nobel Institute, and until his retirement in 1967. He worked as director of the Nobel Institute for Neurophysiology, Karolinska Institute, and Professor. G. shared the Nobel Prize in Physiology or Medicine 1967. with Hartlaynom and Walden 'for discoveries concerning the primary physiological and chemical visual processes in the eye'. In the welcoming speech on the occasion of awarding Carl Gustaf Bernhard of the Karolinska Institute described the works of G., . noting, . that they are 'allowed to come to a conclusion about the existence of different types of cones, . representing three types of spectral sensitivity '; in the future, this conclusion was confirmed by Wald and his colleagues,
. 'The discovery means that the patterns of transmission optic nerve to the brain and determine the perception of color depends on the functioning of the three types of cones', - said Bernhard.
Although Mr.. quite long ago ceased to engage in active research in the physiology of, . his fundamental work - the role of inhibition in the processing of visual information, . the use of ERG, . of color vision - had a tremendous impact on the development of a scientific field.,
. Even before his departure for Dzhonsonovsky Institute, University of Pennsylvania G
. married Baroness Emma Marguerite (Daisy), Brune, who went with him to the United States, the couple had a son. Despite his advanced age, Mr.. leads an active lifestyle: he works in the College of St.. Catherine's in Oxford as a visiting professor of neurophysiology and spends much of his free time sailing under sail on the Baltic Sea.
. His outstanding achievements marked the anniversary prize of the Swedish Society of Physicians (1947), Anders Retzius Gold Medal of the University of Stockholm (1957), Medal F.S
. Donders, Utrecht University (1957). He - a member of the Royal Swedish Academy of Sciences, and from 1963 to 1965. was its president. Honorary member of the American Academy of Arts and Sciences, he is also a foreign member of the Royal Society of London, U.S. National Academy of Sciences and other professional societies.