help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 8: 470-489 (1968)
© 1968 the Biophysical Society

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Segal, J. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Segal, J. R.

Surface Charge of Giant Axons of Squid and Lobster

John R. Segal

ABSTRACT

A method is described for the determination of the electrophoretic mobility of single, isolated, intact, giant axons of squid and lobster. In normal physiological solutions, the surface of hydrodynamic shear of these axons is negatively charged. The lower limit of the estimated surface charge density is -1.9 x 10-8 coul cm-2 for squid axons, -4.2 x 10-8 coul cm-2 for lobster axons. The electrophoretic mobility of squid axons decreases greatly when the applied transaxial electric field is made sufficiently intense; action potential propagation is blocked irreversibly by transaxial electric fields of the same intensity. The squid axon recovers its mobility hours later and is then less affected by transaxial fields. Eventually, a state is reached in which the transaxial field irreversibly reverses the sign of the surface charge. In contrast, there is no obvious effect of electric field on the mobility of lobster axons. The mobility of lobster axons becomes undetectable in the presence of Th4+ at a concentration which blocks the action potential, and in the presence of La3+ at a concentration which does not affect propagation. Quinine does not alter lobster axon mobility at a concentration which blocks action potential conduction. Replacement of extracellular Na+ by K+ is without effect upon lobster axon mobility. The electrophysiological implications of the results are discussed.




This article has been cited by other articles:


Home page
 ScienceHome page
D. Papahadjopoulos and S. Ohki
Stability of Asymmetric Phospholipid Membranes
Science, May 30, 1969; 164(3883): 1075 - 1077.
[Abstract] [PDF]

Home page
 ScienceHome page
L. Y. Wei
Role of Surface Dipoles on Axon Membrane
Science, January 17, 1969; 163(3864): 280 - 282.
[Abstract] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1968 by the Biophysical Society.