Voltage-clamp and current-clamp studies on the action potential in Nitella translucens

Williams, E. D.; Bradley, J.

doi:10.1016/0005-2736(68)90052-7

Cited by 14 publications

(3 citation statements)

References 21 publications

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“…Similar types of vacuolar action potentials have been measured in Ohara globularis (Gaffey and Mullins 1958), Nitella sp. (Findlay 1959), Nitellaflexilis and Ohara braunii (Oda 1960), and Nitella translucens (Williams and Bradley 1968). (Gaffey and Mullins 1958), Nitella clavata (Mullins 1962), Ohara corallina (Hope and Findlay 1964), and Nitellopsis obtusa (Haapanen and Skoglund 1967) have shown that during the action potential there is a marked increase in efflux of potassium and chloride ions from the cell, from which it is inferred that the action potential results from a transient increase in the permeability of the plasmalemma to chloride ions.…”

Section: Introductionmentioning

confidence: 99%

Membrane Electrical Behaviour in Nitellopsis Obtusa

Findlay¹

1970

Aust. Jnl. Of Bio. Sci.

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SummaryThe electrical properties of the two membranes, plasmalemma and tonoplast, bounding the cytoplasm of ' the brackish water characean, NitellopBiB obtUBa, were studied. In a solution approximating the natural pond water, the electrical potential difference between cytoplasm and outside was -141 mY, and between vacuole and cytoplasm +19 mY. The resistance of the plasmalemma was 80,000 n cms, and of the tonoplast, 10,000 n cm2• During an action potential, the peak values of the p.d.'s across plasmalemma and tonoplast were -25 and +57 mY respectively. The action potential was accompanied by a transient decrease in the resistance of the plasmalemma to' 5700 n cm2, and of the tonoplast to 2500 n cms.The effects of changes in external potassium and calcium concentrations on the p.d.'s and resistances of the membranes were examined.During an action potential there was an increased chloride efflux from the vacuole to the outside of the cell. It is concluded that as in other characean species, a transient increase in the permeability of both plasmalemma and tonoplast to chloride ions is responsible for the action potential.

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Section: Introductionmentioning

confidence: 99%

Membrane Electrical Behaviour in Nitellopsis Obtusa

Findlay¹

1970

Aust. Jnl. Of Bio. Sci.

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“…Since the earliest measurements by Osterhaut (21), the action potential in characean cells has been studied by many investigators (for a review, see 5,16) and the significance of the role of calcium ion in determining the transient electrical properties of plasma membrane (plasmalemma) in excitation has been demonstrated and discussed by Findlay (7,8), Findlay and Hope (9), Hope and Findlay (IT), 17,18), and recently by Beilby and Coster (I). It has also been pointed out that the cation-exchange properties of the cell wall do not allow a definite conclusion to be made from the experimental results (1,30). The present preliminary experimental results that the effect of CaCl2 concentration on the half-decay times was appreciable for protoplasts but small for intact cells also suggest a possible role of the cell wall as a cation exchanger to affect the activity of the calcium ion in the vicinity of the cell surface.…”

Section: Discussionmentioning

confidence: 63%

Resting membrane potential and action potential of Nitella expansa protoplasts

Abe

Takeda

Senda

1980

Plant and Cell Physiology

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Inside negative membrane potentials were observed for protoplasts obtained from Nitella expansa leaf internodal cells in media containing 1 to 100 mu CaClz using the microelectrode technique. The potential values were less negative than the membrane potential of intact N. expansa leaf internodal celb. In addition, an action potential consisting of two components-a fast component and a slow component-was induced by electrical stimulation for the protoplasts as well as the intact cells.

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“…Fensom (1966) and Barry (1970) have demonstrated that during the generation of a single spike there are changes in the pressure and volume of the cell, while Kishimoto and Ohkawa (1966) and Oda and Linstead (1975) observed a transient shortening ofthe cell during the propagation ofthe impulse. Findlay (1961) and Williams and Bradley (1968) applied the voltage clamp method to Nitella cells, while Gaffey and Mullins (1958) and Mullins (1962) measured the fluxes of ions during the generation of a single spike. The results of these and other investigations indicate that during the generation of a single spike there is an increase in the permeability of the plasmalemma to Ch and K"*^ ions and their expulsion, in minute quantities, from the cell.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Measurement of the Bioelectric Potential of the Cell Wall and the Vacuoles during the Oscillatory Response to the Nitella Cell

Radenović

Vučinić

1976

Physiologia Plantarum

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Simultaneous measurements of bioelectric potentials of the vacuole and cell wall in cells of Nitella mucronata were made by inserting glass microelectrodes into the vacuole and cell wall respeclively. During the oscillation of the bioelectric potential of the vacuole. induced by sudden changes of the external bathing solution or by the impalement of the cell with a microelectrode. the cell wall potential also exhibited fluctuations of variable intensities in phase and concomitant with spikes of the vacuolar potential oscillation. However, the polarity of the pulses of the cell wall potential was reverse to that of the spikes of the vacuolar potential. These results suggest that the same event is registered at both sides of the plasmalemma membrane across which these phenomena are occurring. The results also support the voltage clamp and tracer flux measurements on these cells which indicate that during the generation of single action potentials, induced by current, the plasma lemma transiently increases its permeability to Cl and K ions expelling them from the cell. The variable intensity of the transient hyperpolarizations of the cell wall potential is explained by the distance of the microelectrode in the cell wall from the plasmalemma.

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Voltage-clamp and current-clamp studies on the action potential in Nitella translucens

Cited by 14 publications

References 21 publications

Membrane Electrical Behaviour in Nitellopsis Obtusa

Membrane Electrical Behaviour in Nitellopsis Obtusa

Resting membrane potential and action potential of Nitella expansa protoplasts

Simultaneous Measurement of the Bioelectric Potential of the Cell Wall and the Vacuoles during the Oscillatory Response to the Nitella Cell

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