Katz (Katz), Bernard( English biophysicist Nobel Prize in Physiology or Medicine, 1970)
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Biography Katz (Katz), Bernard
genus. March 26, 1911
English biophysicist Bernard Katz was born in Leipzig. He was the only child of Eugene Katz (Rabinovich) and Max Katz. In 1929, Mr.. He graduated from the Albert Gymnasium (college preparatory school) and enrolled in the University of Leipzig in the Faculty of Medicine. While studying at the university he was particularly interested in the problem of functions and electrical properties of nerve cells. In 1933, a year before receiving medical degree, K. was awarded the prize Siegfried Garten for physiological research. At this time in Germany, came to power Hitler and the Nazi government began to expel Jews from universities, research laboratories and other institutions. Since K. was a Jew, to remain in Germany for it was dangerous, so in 1935. He moved to England. Here K. continued research in the field of neurophysiology at the University of London under the leadership of Archibald in the. Hill and in 1938. received his doctorate.
By this time, it became clear that a world war is inevitable, and therefore K. the offer of John K. Eccles moved to Australia, where he would be safe. K, , ,
. Dale 20-x - early 30-ц╣ gg., . proved, . that excitation distributed through the synapses are (specialized structures, . which excitation passes with the nerve fiber on nerve fiber either with nerve fiber on muscle fiber or some another cage) using khimicheskikh intermediaries - mediatorov.,
. Among the researchers who adhere to the electrical theory of synaptic transmission, up to 40-ies
. the clearest and most consistent was Eccles. But studies to. and Kuffler, on the effects of chemicals on the transfer of a neuromuscular synapse, his views have changed. At the end of the Second World War, Eccles moved to New Zealand, where he spent the experiments, finally destroyed his own hypothesis.
After returning to London in 1946. K. re-entered the laboratory of the Hill in University College. Since K. knew electrophysiological methods for studying the nerve cells, . but was not a specialist in the field of biochemistry, . He temporarily stopped work on the study of chemical processes in the synapses and joined the research of Alan Hodgkin and Andrew Huxley, . who studied the properties of pulses (action potentials) in individual nerve cells,
. Scientists have found that this process is subject to purely biophysical laws.
In 1950, Mr.. K. returned to work on the study of neuromuscular connections and, together with his colleague Paul Fet-fact employed a new technique for recording electrical impulses in individual neurons. Researchers interested in the electrical activity of the so-called end plates of muscle fibers, which are recorded directly at synapses formed by nerve ending. By the time Dale has found that this activity occurs in the allocation of the neurotransmitter acetylcholine by nerve. It is the interaction between acetylcholine and muscle fibers leads to electrical stimulation and muscle contraction. As he wrote later, K., in the course of these experiments, the researchers' faced with a completely unexpected phenomenon. Turned, . that even without any stimulation of the end plate of the muscle fiber is not at rest, . and, . opposite, . it recorded the electrical activity in the form of individual and emerging randomly weak end-plate potential '.,
. In subsequent studies, particularly with Josц╘ del Castillo, K
. found that 'every weak capacity of end-plate due to the simultaneous action of a large number of molecules of acetylcholine, released in the form of quanta from nerve endings of efferent fibers'. The results of these studies were published in 1954, and in the same year, a number of specialists in electron microscopy, in t.ch. George E. Palade, first described the ultrastructure of synapses. It was a surprising feature - in the presynaptic region (ie. in the end of efferent fibers) contained many small bubbles. Two years later, K. and del Castillo suggested that these vesicles contain acetylcholine. Thus, as subsequently wrote K., it was found that 'normal capacity of the end plate is formed as a result of statistical summation of individual photons, similar to spontaneous low-capacity'.
Soon. asked myself an important question: 'How does the momentum coming into the nerve fiber ... increases the probability of a 'quantum sobytiya'N' Over the next 10 years to. and his colleague Ricardo Miledi in their studies tried to answer this question using techniques similar to those used K., Hodgkin and Huxley in the study of the action potential. By this time it was established that the action potential is caused by the movement of sodium and potassium ions across the membrane of nerve cells. In 1967. K. and Miledi proved that the allocation of neurotransmitter associated with calcium ions.
Using exact methods allow us to study very weak signals, K. and his colleagues to quantify the electrical changes caused by the action of one molecule of acetylcholine, and showed that every weak capacity of end-plate effect corresponds to several thousand of these molecules, ie. exactly the same number that was supposed to be in the same synaptic vesicles.
"For discoveries concerning the mediators of nerve fibers and the mechanisms for their conservation, allocation and inactivation of 'K. in 1970. was awarded the Nobel Prize in Physiology or Medicine. This award he shared with Ulf von Euler, . scientists, . who discovered, . that the mediator of the sympathetic nervous system (division of the autonomic, . or autonomous, , . which is associated with the body's reaction to stress) is a noradrenaline (norepinephrine), , . studied the formation, ,
. for mechanism allocating mediatorov valid not only for holinergicheskih synapses (ie. synapses mediator whom serves as acetylcholine), but for all structures nervous system.
Since 1946 g. K. worked universitaire College in London - first in posts Deputy Director on biophysical Research, then, in 1950 ... 1951., - lecturer fiziologii. In 1952, Mr.. he received professorship Biophysics i zaveduet kafedroj biofiziki.
In 1945, Mr.. K. married Margaret Beyle. In family K. two children.
In 1969. K. was granted a knighthood. He awarded medals Bailey Royal Society physicians (1967) and medals Copley Royal scientific society (1967). K. is a member of the Italian National Academy of Science, the Royal Danish Academy of Arts and Sciences, the American Academy of Arts and Sciences and National Academy of Sciences. In addition, he has the honors at Cambridge University and the Weizmann Institute (Israel).