Membrane potential and input resistance are ambiguous measures of sealing of transected cable-like structures.
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.
Krause
T L
TL
Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston 77555-0641, USA.
Magarshak
Y
Y
Fishman
H M
HM
Bittner
G D
GD
D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D055592:Biophysical Phenomena; D001703:Biophysics; D017097:Electric Impedance; D008564:Membrane Potentials; D008959:Models, Neurological