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Science 27 July 1979:
Vol. 205. no. 4404, pp. 422 - 424
DOI: 10.1126/science.451613
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Articles

Science, Vol 205, Issue 4404, 422-424
Copyright © 1979 by American Association for the Advancement of Science

articles

Reversal potential for noradrenaline-induced hyperpolarization of spinal motoneurons

KC Marshall and I Engberg

By using two separate electrodes with tips inside a single feline motoneuron, current-voltage characteristics were studied during extracellular iontophoresis of noradrenaline. The usually observed hyperpolarization was accompanied by an increase in membrane resistance and became larger with polarizing and smaller with depolarizing currents. During large depolarizing current injections, the noradrenaline-induced potential reversed its direction, usually at a membrane potential of about -20 millivolts. These data are compatible with the concept that noradrenaline hyperpolarizes nerve cells by decreasing resting membrane conductances to sodium and potassium ions. The observation could also be explained by a nonspecific decrease in ion permeability that is associated with a hyperpolarization due to sodium pump activation.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Synaptic Control of Motoneuronal Excitability.
J. C. Rekling, G. D. Funk, D. A. Bayliss, X.-W. Dong, and J. L. Feldman (2000)
Physiol Rev 80, 767-852
   Abstract »    Full Text »    PDF »
A coeruleo-spinal system in culture.
K. Marshall, R. Pun, W. Hendelman, and P. Nelson (1981)
Science 213, 355-357
   Abstract »    PDF »


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