Sunday, January 6, 2013
Erlanger's field was physiology. His studies included the physiology of the circulatory and nervous systems. His early research was on the human circulatory system. In 1904 he designed a sphygmomanometer, a device for measuring blood pressure. With it he studied relation between blood pressure and orthostatic albuminuria, a condition where protein appears in the urine of standing patients. During the First World War he studied wound shock and he helped develop therapies for it that were used on United States troops in Europe.
Working with his former student Herbert Gasser, Erlanger developed oscilloscope that could record nerve impulses. Up to that point it had been impossible to study nerve impulses directly, as they were too weak to be detected with the available technology. In 1920 H. Sydney Newcomer invented an amplifier that allowed nerve impulses to be detected. Using this amplifier, Erlanger and Gasser developed their oscilloscope. Nerve impulses are electrical currents generated by the movement of sodium ions into the nerve cell. When a nerve cell is stimulated protein channels in the nerve cell's cellular membrane open and sodium ions flood in. The movement of sodium ions into the cell causes a change in the membrane potential and the flood of sodium ions crossing the membrane into the cell moves down the length of the cell, conducted like an electrical current. Using the oscilloscope they developed Erlanger and Gasser found that larger nerve cells conduct impulses faster than smaller nerve cells and that different nerve fibers have different functions. For their pioneering work studying nerve fibers Erlanger and Gasser were awarded the 1944 Nobel Prize in Medicine and Physiology.
Erlanger died of heart failure on December 5, 1955.
Davis, Hallowell; "Joseph Earlanger: 1875-1955"; National Academy Press; 1970
Joseph Erlanger Nobel Biography
Joseph Erlanger Wikipedia Entry