Determination of excitation sites during magnetic stimulation of nerve fibers

In this paper we present results of in vitro experiments on magnetic stimulation of nerve fibers. Sciatic nerves from bull frogs and phrenic nerves from dogs were excited both electrically and magnetically. During electrical stimulation, the excitation sites are known and correspond to the location of the stimulating electrode. However, during magnetic stimulation excitation sites are not known. The excitations sites for magnetic stimulation are determined using latencies obtained for electrical stimulation. In accordance with our prior theoretical predictions, experiments on magnetic stimulation of nerve fibers indicate that short nerve fibers are excited at terminations and geometric inhomogeneities along the fibers.