THE FORM OF THE RECORD OF THE ACTION POTENTIAL OF VERTEBRATE NERVE AT THE STIMULATED REGION

Abstract

Treating the nerve as a physical conductor, the polarizing effects of currents stimulating it can be approximately eliminated from the record by balancing the nerve in a Wheatstone bridge as if it consisted of a shunted condenser. Imperfect balance against a single condenser in the opposite arm of the bridge is due to complexity of structure in the nerve trunk, different elements of which have different reactances. The local electric effect of stimulation appears only as a polarization counter EMF. The nerve action potential may be recorded from this balanced bridge as from the stimulated point, where it brings about a local uncompensated potential change in 1 arm. The rising phase of the potential so recorded is a very asymmetrical sigmoid approaching an exponential curve; a provisional analysis of the falling phase as the sum of 2 curves is suggested.