The internal potential of Neurospora appears to have two components, one (a) which is reduced by anoxia or abolished by respiratory inhibitors such as azide and 2,4-dinitrophenol, and (b) a fraction that remains in the presence of respiratory inhibitors and is sensitive to the external potassium concentration. Under standard conditions 1 mM azide or dinitrophenol diminishes internal potentials from near -200 mv to about -30 mv within 1 minute and at a maximal rate of 20 mv/second. The internal potential usually recovers within 10 minutes after the inhibitor has been removed. The effect of carbon monoxide on the internal potential is similar to that of azide or dinitrophenol, but can be reversed by visible light, specifically of the wavelengths (430 mµ and 590 mµ) known to decompose cytochrome-CO complexes in yeast. Respiration and internal potentials vary proportionally with azide concentration, but dinitrophenol at low (3 x 10-6 M) concentrations enhances oxygen consumption without affecting the internal potential. In the presence of 0.1 mM calcium, the fraction of the internal potential which persists during respiratory inhibition increases (becomes more negative) about 30 mv for each tenfold decrease of external potassium over the range 10 to 0.1 mM. The surface resistivity of Neurospora, normally about 5000 ohm.cm2, is unchanged by respiratory inhibitors during the period of rapid potential shift.
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1 September 1965
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September 01 1965
Electrical Properties of Neurospora crassa : Respiration and the intracellular potential
Clifford L. Slayman
Clifford L. Slayman
From The Rockefeller University, New York.
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Clifford L. Slayman
From The Rockefeller University, New York.
Dr. Slayman's present address is the Department of Physiology, Western Reserve University, Cleveland
Received:
April 05 1965
Online ISSN: 1540-7748
Print ISSN: 0022-1295
Copyright © 1965 by The Rockefeller University Press
1965
J Gen Physiol (1965) 49 (1): 93–116.
Article history
Received:
April 05 1965
Citation
Clifford L. Slayman; Electrical Properties of Neurospora crassa : Respiration and the intracellular potential . J Gen Physiol 1 September 1965; 49 (1): 93–116. doi: https://doi.org/10.1085/jgp.49.1.93
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