Born in San Francisco, Joseph Erlanger studied at the University of California (1895) and the John Hopkins Medical School (1899), where he worked for a seven years. From 1900 to 1906, he was an assistant in physiology at the university under William H. Howell.
Erlanger was appointed professor of physiology at the University of Wisconsin (1906-1910) and there began a successful collaboration with his student Gasser. He founded the department of physiology at the University of Wisconsin’s, new medical school. In 1910, he accepted an appointment as professor and head of physiology at Washington University in St. Louis,(1910-46), and Gasser joined him soon after.
Priori to 1921, Erlanger’s research focused primarily on the cardiovascular system. While a medicals students, he designed improvement to the sphygmomanometer a device for measuring blood pressure in the fingers.
At Wisconsin Erlanger and Gasser studied various means of applying electronics to physiological research. They devised a method of applying electric responses occurring in an individual nerve fiber and were able to record them using the oscilloscope. This happened in 1922.
An amplified impulse produced a characteristics wave form on the screen, which could then be studied. In 1932 Erlanger and Gasser found that the fibers within a nerve conduct impulses at different rate, depending on fibers thickness, and that each fiber has a different threshold of excitability. Different fibers produced different wave forms on the screen, indicating that different types of impulses were being passed.
This lead to their formulation of the law that the velocity of nervous impulses is directly proportional to the diameter of the nerve fiber.
Erlanger, Joseph (1874-1965)
