Interference of Injected Tetra-n-Propyl-ammonium Bromide with Outward Sodium Ion Current in Squid Giant Axons

Nature ◽  
1966 ◽  
Vol 211 (5046) ◽  
pp. 322-323 ◽  
Author(s):  
CLAY ARMSTRONG
Keyword(s):  
Sodium Ion ◽  
Ion Current ◽  
Ammonium Bromide ◽  
Giant Axons

On the Persistent Sodium Current in Squid Giant Axons

2003 ◽  
Vol 89 (1) ◽  
pp. 640-644 ◽  
Author(s):  
John R. Clay
Keyword(s):  
Ion Channel ◽  
Sodium Current ◽  
Persistent Current ◽  
Sodium Ion ◽  
Ion Current ◽  
Peak Amplitude ◽  
Potential Range ◽  
Slow Inactivation ◽  
Giant Axons ◽  
Low Threshold

R. F. Rakowski, D. C. Gadsby, and P. DeWeer have reported a persistent, tetrodotoxin-sensitive sodium ion current ( I NaP) in squid giant axons having a low threshold (-90 mV) and a maximal inward amplitude of −4 μA/cm2 at −50 mV. This report makes the case that most of I NaP is attributable to an ion channel mechanism distinct from the classical rapidly activating and inactivating sodium ion current, I Na, which is also tetrodotoxin sensitive. The analysis of the contribution of I Na to I NaP is critically dependent on slow inactivation of I Na. The results of this gating process reported here demonstrate that inactivation of I Na is complete in the steady-state for V > −40 mV, thereby making it unlikely that I NaP in this potential range is attributable to I Na. Moreover, −90 mV is well below I Na threshold, as demonstrated by the C. A. Vandenberg and F. Bezanilla model of I Na gating in squid giant axons. Their model predicts a persistent current having a threshold of −60 mV and a peak amplitude of −25 μA/cm2 at −20 mV. Modulation of this component by the slow inactivation process predicts a persistent current that is finite in the −60- to −40-mV range having a peak amplitude of −1μA/cm-2 at −50 mV. Subtraction of this current from the I NaP measurements yields the portion of INaP that appears to be attributable to an ion channel mechanism distinct from I Na.

scholarly journals The Effects of Several Alcohols on the Properties of the Squid Giant Axon

1964 ◽  
Vol 48 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Clay M. Armstrong ◽  
Leonard Binstock
Keyword(s):  
Potassium Conductance ◽  
Membrane Conductance ◽  
Giant Axon ◽  
Squid Giant Axon ◽  
Sodium Ion ◽  
Ion Current ◽  
Resting Potential ◽  
Membrane Capacity ◽  
Monomolecular Films ◽  
Steady State Inactivation

The effects of several alcohols on the resting potential, action potential, and voltage-clamp currents of the squid giant axon have been measured. All the alcohols employed are similar in that they depress maximum sodium conductance much more than maximum potassium conductance. Octyl alcohol differs from the others (C2 through C5) in that it has less tendency to depolarize the axon. Depolarization is always accompanied by a decrease of gK near the resting potential, such that the ratio gK/gleak is decreased. Steady-state inactivation of the sodium ion current is unaffected by alcohols, as is membrane capacity. Resting membrane conductance is usually decreased by alcohols. The findings are discussed in relation to work on monomolecular films.

scholarly journals Dichloro-substituted phenyl amino propanamides exhibit anticonvulsant effect and reduce inward sodium ion current (NaV1.6)

2017 ◽  
Vol 4 (3) ◽  
pp. 168-174
Author(s):  
S. Malami ◽  
A.Y. Idris ◽  
A.H. Yaro ◽  
J.A. Anuka ◽  
I.M. Hussaini ◽  
...  
Keyword(s):  
Sodium Ion ◽  
Ion Current ◽  
Anticonvulsant Effect

Quantitative Measurements on the Ion Etching of TMV

1973 ◽  
Vol 31 ◽  
pp. 336-337
Author(s):  
Irwin Bendet ◽  
Nabil Rizk
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Ion Current ◽  
Beam Diameter ◽  
Ion Etching ◽  
Preliminary Results ◽  
Quantitative Measurements ◽  
Monitoring Devices

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.

Ultrastructural Features of Normal and Diseased Hair Revealed by Ion Beam Etching and Freeze Fracture

1975 ◽  
Vol 33 ◽  
pp. 358-359
Author(s):  
M. Spector ◽  
A. C. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ectodermal Dysplasia ◽  
Ion Beam ◽  
Freeze Fracture ◽  
Ion Current ◽  
Ion Beam Etching ◽  
Pili Torti ◽  
Argon Ion ◽  
Scanning Electron

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

CuS2 sheets: a hidden anode material with a high capacity for sodium-ion batteries

2021 ◽  
Author(s):  
Shaohua Lu ◽  
Weidong Hu ◽  
Xiaojun Hu
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
Low Cost ◽  
High Capacity ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Sodium Ion Batteries

Due to their low cost and improved safety compared to lithium-ion batteries, sodium-ion batteries have attracted worldwide attention in recent decades.

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