THE ORIGIN OF RAPID CHANGES IN BIREFRINGENCE, LIGHT-SCATTERING AND DYE ABSORBENCY ASSOCIATED WITH EXCITATION OF NERVE-FIBERS

By comparing the time-courses of rapid optical changes in the garfish olfactory nerve evoked by electric stimulation with those of mechanica l changes observed at the site of optical recording, the origin of opt ical changes in the nerve has been investigated. Based on the finding that the time-course of the birefringence change accurately coincides with that of swelling of the nerve, optical changes are interpreted as being brought about by invasion of water into the superficial layer o f the nerve fibers. A close relationship has also been demonstrated be tween nerve swelling and changes in light scattering and in dye absorb ance.