TRANSITIONAL DECREMENT OF INTENSITY IN NERVE CONDUCTION

Abstract

A study of the influence of the length of the nerve compressed on the time required to block conduction in the sciatic of the frog, as indicated by changes in tension developed by the attached muscle when the nerve is stimulated on the far side of the compressed area. The method employed of compressing the nerve between weighted hard rubber blocks gave more uniform results when 2 nerve muscle preparations of the same frog were employed, indicating a varying susceptibility of the nerves of different animals. The time required to stop conduction under a given pressure per unit length of nerve was the same for 8 mm. and 16 mm. compression distances, but when the pressure involved a length of 4 mm. it took nearly twice as long to block conduction in a majority of the fibers. It is concluded that these results give evidence of the existence of a transitional decrement in nerve conduction in the compressed region extending over a distance of not less than 4 mm. nor over 8 mm.