Erlanger is a US physiologist who, in collaboration with Herbert Gasser, developed techniques for recording nerve impulses using a cathode ray oscilloscope.
In 1944 they shared the Nobel Prize for physiology or medicine for demonstrating that different fibers in the same nerve cord can have different functions.
Erlanger qualified at the University of California and the John Hopkins Medical School (1899), where he worked for a seven years. He was appointed professor of physiology at the University of Wisconsin (1906-1910) and there began a successful collaboration with his student Gasser. Erlanger moved to the Washington University, St. Louis (1910-46), and Gasser joined him soon after.
There they 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.
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.