Premium
Sign reversal of permselective membranes: A possible mechanism for neural conduction
Author(s) -
De Kőrösy Francis
Publication year - 1963
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1963.070070407
Subject(s) - membrane , chemistry , counterion , ion , membrane potential , chemical physics , organic chemistry , biochemistry
An electrochemical mechanism is sought for to explain the sudden transient change of potential across a nerve membrane during neural conduction. Ion‐permselective membranes change the sign of their permselectivity if the charge of their fixed ions is overcompensated for by highly charged counterions which become strongly bound to these fixed sites by electrostatic forces. Imagine a membrane with its sign thus reversed beyond a given borderline: cations could traverse on one side in the vicinity of this line and anions on the other, while no ions would traverse pure membrane faces themselves. Thus concentrations would be equalized at the borderline by passive diffusion, while the sign of membrane potential would change from one side to the other of the border. A mechanism for automatic propagation of the border along the membrane is suggested. Sign reversal of membranes can also be caused by covalent bonding of oppositely charged groups to a charged membrane site, for instance by esterification of a carboxyl group or of a phosphoric acid group of a lipoproteid nerve membrane with the amino alcohol choline. Hydrolysis of such an ester would cause the sign of the membrane to revert to its original direction. Such acetic sites and choline abound on nerve membranes, together with enzymes, which are known to split and synthesize choline esters. Their electrochemical function in neutral conduction might well be this changing of sign of membrane permselectivity.