Fine structural changes of myelinated nerve associated with copperhead envenomation

Summary The fine structure of right sciatic nerves of Swiss white mice was studied after being exposed to a venom solution ofAgkistrodon contortrix laticinctus (broad-banded copperhead) and to 0.9% NaCl solutions for periods of 1, 2 or 3 h. There was some Wallerian-like degeneration in all groups of nerves in the experiment. Additional neuropathological changes were noted in the nerves exposed to venom solutions.The connective tissue was affected most severely, while the basal lamina was unaffected. Schwann cells were vacuolated, and in the most extreme case, a type of myelin splitting occurred which was considered as a demyelinative effect. The results were compared to those of Martin and Rosenberg (1968) [15] on studies of the giant squid axon. References to additional fine structural studies of various other neuropathies were given.This investigation was submitted as a partial requirement for the Master of Science Degree, Department of Anatomy, Colorado State University and was supported by U.S. Public Health Service Grant # 5 RO1 GM-15591 and # 5 RO1 FD-00014 and Career Development Award # 5 KO4 GM-41786 from the National Institutes of Health (to A. T. Tu). The work was done in the Electron Microscope Training Laboratory, Colorade State University.