title: Membrane potential and input resistance are ambiguous measures of sealing of transected cable-like structures.
abstract: For many years, membrane potential (Vm) and input resistance have been used to characterize the electrophysiological nature of a seal (barrier) that forms at the cut end of a transected axon or other extended cytoplasmic structure. Data from a mathematical and an analog model of a transected axon and other theoretical considerations show that steady-state values of Vm and input resistance measured from any cable-like structure provide a very equivocal assessment of the electrical barrier (seal) at the cut end. Extracellular assessments of injury currents almost certainly provide a better electrophysiological measure of the status of plasma membrane sealing because measurements of these currents do not depend on the cable properties of extended cytoplasmic processes after transection.
authors.affiliation: Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston 77555-0641, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Krause
authors.forename: Y
authors.initials: Y
authors.lastname: Magarshak
authors.forename: H M
authors.initials: HM
authors.lastname: Fishman
authors.forename: G D
authors.initials: GD
authors.lastname: Bittner
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D055592:Biophysical Phenomena; D001703:Biophysics; D017097:Electric Impedance; D008564:Membrane Potentials; D008959:Models, Neurological