Voltage clamp of the Aplysia giant neurone: early sodium and calcium currents.
D. Geduldig,Raphael Gruener +1 more
TLDR
The membrane properties of the Aplysia giant neurone were studied under controlled voltage conditions and emphasis was placed on the early transient currents resulting from step polarizations applied while the ganglion was immersed in different test solutions.Abstract:
1. The membrane properties of the Aplysia giant neurone were studied under controlled voltage conditions. Emphasis was placed on the early transient currents resulting from step polarizations applied while the ganglion was immersed in different test solutions.
2. Early inward-going currents were observed when the neurone was bathed in normal saline (containing both Na and Ca), in Ca-free (Na-containing) saline, in Na-free (Ca-containing) saline, and in the normal saline to which tetrodotoxin 10−5 g/ml. was added. When both Na and Ca are absent from the bathing solution no evidence for early inward-going current could be found.
3. When tetrodotoxin is added to the normal saline, the maximum inward-going current is reduced, and no further reduction of this current is observed when the external Na-concentration is subsequently halved in the presence of the drug. When the external Ca-concentration is increased fivefold in the presence of the drug, the maximum transient current increases significantly.
4. Hyperpolarizing prepulses result in a membrane inactivation in the presence of tetrodotoxin or in the absence of Na. In the presence of Na (and absence of tetrodotoxin) no such voltage-dependent inactivation occurs, and for this case, inactivation results only from depolarizing prepulses.read more
Citations
More filters
Journal ArticleDOI
Three pharmacologically distinct potassium channels in molluscan neurones.
TL;DR: It is concluded that three sets of potassium selective channels contribute to the outward current and that these channels can be separated pharmacologically.
Journal ArticleDOI
Inactivation of Ca channels
Roger Eckert,John E. Chad +1 more
TL;DR: Ca-dependent inactivation develops non-linearly with Ca entry and accumulation with CaEntry and accumulation, and Voltage-dependent activation may counteract Ca- dependent inactivation.
Journal ArticleDOI
Two Fast Transient Current Components during Voltage Clamp on Snail Neurons
TL;DR: Voltage clamp currents from medium sized ganglion cells of Helix pomatia have a fast transient outward current component in addition to the usually observed inward and outward currents.
Journal ArticleDOI
Pharmacological characterization of different types of GABA and glutamate receptors in vertebrates and invertebrates.
A Nistri,A Constanti +1 more
TL;DR: In this article, the authors present a list of abbreviations for nouns and adjectives: list of abbreviations 118.1.2.3.3].
References
More filters
Journal ArticleDOI
The effect of sodium ions on the electrical activity of the giant axon of the squid
A. L. Hodgkin,B. Katz +1 more
Journal ArticleDOI
The action of calcium on the electrical properties of squid axons
B. Frankenhaeuser,A. L. Hodgkin +1 more
Journal ArticleDOI
Measurement of current-voltage relations in the membrane of the giant axon of Loligo.
TL;DR: The importance of ionic movements in excitable tissues has been emphasized by a number of recent experiments which are consistent with the theory that nervous conduction depends on a specific increase in permeability which allows sodium ions to move from the more concentrated solution outside a nerve fibre to the more dilute solution inside it.
Journal ArticleDOI
The dual effect of membrane potential on sodium conductance in the giant axon of Loligo
A. L. Hodgkin,A. F. Huxley +1 more
TL;DR: This paper contains a further account of the electrical properties of the giant axon of Loligo and deals with the 'inactivation' process which gradually reduces sodium permeability after it has undergone the initial rise associated with depolarization.
Journal ArticleDOI
Tetrodotoxin Blockage of Sodium Conductance Increase in Lobster Giant Axons
TL;DR: Observations have been made of sodium and potassium currents in the lobster giant axons treated with tetrodotoxin by means of the sucrose-gap voltage-clamp technique, and it is concluded that tetrodOToxin blocks the action potential production through its selective inhibition of the sodium-carrying mechanism while keeping the potassium- Carrying mechanism intact.
Related Papers (5)
A quantitative description of membrane current and its application to conduction and excitation in nerve
A. L. Hodgkin,A. F. Huxley +1 more
The action of calcium on the electrical properties of squid axons
B. Frankenhaeuser,A. L. Hodgkin +1 more
Voltage clamp studies of a transient outward membrane current in gastropod neural somata
J. A. Connor,Charles F. Stevens +1 more