DISTORTION OF ACTION POTENTIALS AS RECORDED FROM THE NERVE SURFACE

Abstract

Physical factors inherent in nerve structure are found to influence the form of the action potential wave of nerve, and physical properties of the electric circuits involved in different leads from the nerve serve to explain distortion occurring in the record taken by the cathode ray oscillograph. The distorting factors are parallel conducting pathways from excited region to leads; polarization of these pathways, particularly when the nerve''s connective tissue sheath is involved; and the mutual effects of reactance in the stimulating and recording leads. Diphasic potential waves may be obtained from nerves which have been killed under 1 leading-off electrode to render the record of the response mono-phasic, due to potentials developed at the killed end. Double-humped waves resembling repetitive processes may be obtained at cut branches, or where any conductor such as a piece of tissue or an idle electrode makes contact with the nerve between leads to the recording instrument.