J Physiol Wellcome Trust-funded researchers
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


J Physiol Vol 354 pp 139-162
Copyright © 1984 by The Physiological Society
This Article
Right arrow Full Text (PDF)
Services
Right arrow Email this article to a friend
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
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Connor, J A
Right arrow Articles by Hockberger, P
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Connor, J A
Right arrow Articles by Hockberger, P

A novel membrane sodium current induced by injection of cyclic nucleotides into gastropod neurones.

J A Connor and P Hockberger

Injection of cyclic AMP (cAMP) or cyclic GMP into identifiable neurones from several different gastropod species immediately depolarized the cell membranes in a dose-dependent manner. Doses were monitored photometrically and evidence is presented for depolarizing effects following nucleotide injections of as little as 30-35 mumol. The depolarizing effect was reversible and was demonstrated under voltage clamp to be primarily the result of a nucleotide-induced, transient increase in a membrane Na current, INa (cAMP). The charge-carrying species was identified by using ion-substituted salines, reversal potential in low-Na saline, and intracellular ion-sensitive electrode measurements. The current was resistant to tetrodotoxin, ouabain and amiloride. Substituting Trisma, tetramethylammonium or bis-tris propane for Na prevented the induced current, whereas Li substitution did not. Duration of the induced current was greatly prolonged in neurones bathed in the phosphodiesterase inhibitor isobutylmethylxanthine, or following injection of any of several cAMP analogues, indicating that the reversible nature of the current stems primarily from in situ hydrolysis of the injected dose and not current inactivation. Amplitude of the induced current either remained constant or decreased over the voltage range where it could be easily measured, i.e. -30 greater than Vm greater than -100 mV, reflecting a voltage as well as a chemical sensitivity of INa (cAMP).




This article has been cited by other articles:


Home page
J. Physiol.Home page
M. V. Podda, M. D'Ascenzo, L. Leone, R. Piacentini, G. B. Azzena, and C. Grassi
Functional role of cyclic nucleotide-gated channels in rat medial vestibular nucleus neurons
J. Physiol., February 1, 2008; 586(3): 803 - 815.
[Abstract] [Full Text] [PDF]


Home page
J. Neurophysiol.Home page
E. S. Nikitin, T. Kiss, K. Staras, M. O'Shea, P.R. Benjamin, and G. Kemenes
Persistent Sodium Current Is a Target for cAMP-Induced Neuronal Plasticity in a State-Setting Modulatory Interneuron
J Neurophysiol, January 1, 2006; 95(1): 453 - 463.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
P. E. MacDonald, W. El-kholy, M. J. Riedel, A. M. F. Salapatek, P. E. Light, and M. B. Wheeler
The Multiple Actions of GLP-1 on the Process of Glucose-Stimulated Insulin Secretion
Diabetes, December 1, 2002; 51(90003): S434 - 442.
[Abstract] [Full Text] [PDF]


Home page
J. Neurophysiol.Home page
P. F. Van Soest, J. C. Lodder, and K. S. Kits
Activation of Protein Kinase C by Oxytocin-Related Conopressin Underlies Pacemaker Current in Lymnaea Central Neurons
J Neurophysiol, November 1, 2000; 84(5): 2541 - 2551.
[Abstract] [Full Text] [PDF]


Home page
J. Neurophysiol.Home page
P. F. van Soest and K. S. Kits
Vasopressin/Oxytocin-Related Conopressin Induces Two Separate Pacemaker Currents in an Identified Central Neuron of Lymnaea stagnalis
J Neurophysiol, September 1, 1997; 78(3): 1384 - 1393.
[Abstract] [Full Text] [PDF]


Home page
J. Neurosci.Home page
G. F. Wilson, F. C. Richardson, T. E. Fisher, B. M. Olivera, and L. K. Kaczmarek
Identification and Characterization of a Ca2+-Sensitive Nonspecific Cation Channel Underlying Prolonged Repetitive Firing in Aplysia Neurons
J. Neurosci., June 1, 1996; 16(11): 3661 - 3671.
[Abstract] [Full Text] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1984 The Physiological Society.