VOLUME CONDUCTOR FIELDS OF ACTION CURRENTS.

The formulation of Lorente de Nó for the potential distribution in a volume conductor due to a contained bioelectric source is reviewed. The aforementioned formula is based on data taken from the bioelectric source in air (excised). This work is extended to the derivation of a formula which depends upon quantities available from in situ measurements. The latter formula appears to simplify to the form[FORMULA: see text]where J(n) is the normal current density flow across the surface S(o) that bounds the bioelectric source. The simplification is considered in some detail for a hypothetical action potential on a circular cylindrical axon, and is shown to be adequately substantiated for this case.