In 1906, Erlanger accepted a position as the first chair of physiology at the University of Wisconsin in Madison. In 1910, he left to take a position as professor at Washington University in St. Louis; the St. Louis position offered Erlanger more funding for his projects. Herbert Spencer Gasser, Erlanger's former student at Wisconsin, joined Erlanger's laboratory soon after the move. During World War I, the pair contributed to the research effort examining the effects of shock.[4] As part of this work, Erlanger was able to produce heart block in an animal model by clamping the bundle of His and tightening it.[5] Together, they managed to amplify the action potential of a bullfrogsciatic nerve in 1922 and published the results in the American Journal of Physiology.[2][6] It is uncertain why the pair had such a sudden shift in interest to neuroscience, as Erlanger was already widely respected in the cardiology field.[7]
Erlanger and Gasser were able to modify a Western Electricoscilloscope to run at low voltages. Prior to this modification, the only method available to measure neural activity was the electroencephalograph, which could only show large-scale electrical activity. With this technology, they were able to observe that action potentials occurred in two phases—a spike (initial surge) followed by an after-spike (a sequence of slow changes in potential).[10] They discovered that neurons were found in many forms, each with their own potential for excitability. With this research, the pair discovered that the velocity of action potentials was directly proportional to the diameter of the nerve fiber. The partnership ended in 1931, when Gasser accepted a position at Cornell University.[11] In 1944, they won the Nobel Prize in Medicine or Physiology for these discoveries.[2]
^Jeffrey, Kris (2001). Machines in Our Hearts: The Cardiac Pacemaker, the Implantable Defibrillator, and American Health Care. Baltimore, MD: Johns Hopkins University Press. ISBN978-0801865794.
Joseph Erlanger on Nobelprize.org including the Nobel Lecture on December 12, 1946 The Discovery of Vitamin K, Its Biological Functions and Therapeutical Application