This project will investigate a series of approximately a dozen episodes in the development between 1905 and 1965 of modern fundamental concepts of nerve conduction and synaptic transmission. Major figures whose work will be studied include Lucas, Adrian, Forbes, Erlanger, Gasser, Bronk, Cannon, Dale, Loewi, Cole, Hodgkin, Huxley, Eccles and Katz. Research will focus on how these and other investigators used new electrical instrumentation, special biological materials, and biophysical models to elucidate a series of general principles concerning the way neurons and synapses transmit and process information. This historical recontruction, interpretation, and analysis will be based on published papers and books, on manuscript laboratory notes and correspondence where avalilable, and on detailed focused interviews with investigators and/or their students and associates.