A New Concentration Jump Strategy Reveals the Lifetime of i-Motif at Physiological pH without Force

2018 ◽  
Vol 90 (5) ◽  
pp. 3205-3210 ◽  
Author(s):  
Sagun Jonchhe ◽  
Prakash Shrestha ◽  
Katia Ascencio ◽  
Hanbin Mao
Keyword(s):  
Concentration Jump

A new oil-gate concentration jump technique applied to inside-out patch-clamp recording

1988 ◽  
Vol 255 (4) ◽  
pp. H980-H984 ◽  
Author(s):  
D. Y. Qin ◽  
A. Noma
Keyword(s):  
K Channel ◽  
Narrow Slit ◽  
Patch Clamp Recording ◽  
Concentration Jump ◽  
Guinea Pig Heart ◽  
Ventricular Cells ◽  
Pipette Tip ◽  
Time Courses ◽  
Inside Out ◽  
Membrane Patch

A new method was developed to instantaneously replace the solution on the inner side of an inside-out membrane patch in order to measure time courses with which active substances acted on single ionic channels. Inside-out membrane patches were isolated from single ventricular cells of the guinea pig heart. The recording bath consisted of two chambers separated by a partition having a narrow slit. Mixing of two test solutions through this slit was prevented by filling it with paraffin oil. The pipette tip with a tightly sealed inside-out membrane patch was moved through the oil from one solution to the other so that the pipette tip was instantaneously exposed to a new solution. When the pipette tip was jumped between different K+ concentrations, the leak current through the membrane patch increased or decreased with a half time of 6.3 +/- 3.0 ms (n = 15). The amplitude of single K+ channel currents changed to a new steady level within approximately 20 ms. These time courses were well explained by diffusion of K+ in the dead space between the pipette tip opening and the membrane patch. An application of this method to the ATP-regulated K+ channel revealed a latent period of 1-2 s before the channel started its activity after the instantaneous removal of ATP, whereas no obvious latency was observed in the rapid suppression of the channel, which was completed in 100-300 ms after reapplying ATP.

scholarly journals 1D Measurement of Sodium Ion Flow in Hydrogel After a Bath Concentration Jump

2015 ◽  
Vol 43 (7) ◽  
pp. 1706-1711 ◽  
Author(s):  
R. W. Roos ◽  
L. Pel ◽  
H. P. Huinink ◽  
J. M. Huyghe
Keyword(s):  
Sodium Ion ◽  
Concentration Jump ◽  
Ion Flow ◽  
Bath Concentration

Differential effects of extra- and intracellular anions on GABA-activated currents in bullfrog sensory neurons

1989 ◽  
Vol 62 (6) ◽  
pp. 1388-1399 ◽  
Author(s):  
N. Akaike ◽  
N. Inomata ◽  
T. Yakushiji
Keyword(s):  
Sensory Neurons ◽  
Dose Response ◽  
Kinetic Properties ◽  
Gamma Aminobutyric Acid ◽  
Response Curves ◽  
Concentration Jump ◽  
Inward Currents ◽  
Selective Channel ◽  
Concentration Clamp Technique ◽  
Dose Response Curves

1. Kinetic properties of gamma-aminobutyric acid (GABA)-gated inward and outward anion currents were investigated in the frog sensory neurons perfused internally and externally with various anions with the use of a rapid concentration-jump (termed as 'concentration-clamp') technique. 2. Extracellular Br- [( Br-]o) shifted the dose-response curves of GABA-induced inward anion currents to the left without affecting the maximum values, whereas [Cl-]o, [I-]o, [No3-]o, [HCOO-]o, and [CH3COO-]o altered the rate of desensitization differently without shifting the GABA dose-response curves, indicating that the kinetics of desensitization phase are affected differently by various extracellular anions. 3. [CH3COO-]o suppressed the maximum current of the dose-response curve of the GABA-induced inward ICl without affecting Kd. 4. Both activation and desensitization phases of GABA-induced ICl consisted of fast and slow components, respectively. [Br-]o, [I-]o, and [NO3-]o significantly prolonged the slow desensitization component, whereas both [HCOO-]o and [CH3COO-]o shortened it. The fast desensitization and the fast and slow activation components were also affected by these foreign anions. 5. GABA dose-response curves of inward currents carried by various intracellular anions (Cl-, Br-, NO3-, I-, SCN-, HCOO-, F-, CH3COO-, CH3CH2COO-, BrO3-, and ClO3-) while keeping a constant [Cl-]o had a constant Kd value but different saturating maximum currents. There were no marked differences among their current kinetics except in the case of SCN-, indicating that the current kinetics is not affected by replacing intracellular Cl- [( Cl-]i) with various foreign anions. 6. The configuration and amplitude of GABA-gated outward anion currents at a constant [Cl-]i reflected the extracellular action of individual anions on the anion-binding site of GABA receptor associated with the anion-selective channel. 7. The relative conductances of the various anions, calculated from the maximum peak currents in dose-response curves of the GABA-induced inward anion currents at a constant [Cl-]o, was in the sequence: I- greater than Br- greater than or equal to NO3- greater than ClO3- greater than SCN- greater than or equal to Cl- greater than HCOO- greater than BrO3- greater than CH3COO- greater than F- greater than CH3CH2COO-.(ABSTRACT TRUNCATED AT 400 WORDS)

Dimerization kinetics of thiacarbocyanine dyes by photochemically induced concentration jump

2004 ◽  
Vol 386 (4-6) ◽  
pp. 301-306 ◽  
Author(s):  
Alexander K Chibisov ◽  
Tatyana D Slavnova ◽  
Helmut Görner
Keyword(s):  
Concentration Jump ◽  
Kinetics Of

Structural changes in graphite-to-diamond transition on the P-T link of minimum concentration jump in carbon

1992 ◽  
Vol 9 (1-6) ◽  
pp. 124-127
Author(s):  
A. V. Lysenko ◽  
E. A. Pugach ◽  
L. A. Shul'man ◽  
S. I. Filipchenko
Keyword(s):  
Structural Changes ◽  
Concentration Jump ◽  
Minimum Concentration

Boundary Conditions for Multi-Component Slip-Flows Based on the Kinetic Theory of Gases

2008 ◽  
Author(s):  
Azad Qazi Zade ◽  
Metin Renksizbulut ◽  
Jacob Friedman
Keyword(s):  
Kinetic Theory ◽  
Boundary Conditions ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Gas Flows ◽  
Kinetic Theory Of Gases ◽  
Concentration Jump ◽  
Physical Importance ◽  
Jump Velocity ◽  
Slip Flows

General temperature-jump, velocity-slip, and concentration-jump conditions on solid surfaces in rarefied multi-component gas flows are developed using the kinetic theory of gases. The presented model provides general boundary conditions which can be simplified according to the problem under consideration. In some limiting cases, the results of the current work are compared to the previously available and widely used boundary conditions reported in the literature. The details of the mathematical procedure are also provided to give a better insight about the physical importance of each term in the slip/jump boundary conditions. Also the disagreements between previously reported results are investigated to arrive at the most proper expressions for the slip/jump boundary conditions. The temperature-jump boundary condition is also modified to handle polyatomic gas flows unlike previously reported studies which were mostly concerned with monatomic gases.

scholarly journals Synaptically Released Neurotransmitter Fails to Desensitize Postsynaptic GABAA Receptors in Cerebellar Cultures

2001 ◽  
Vol 85 (5) ◽  
pp. 1847-1857 ◽  
Author(s):  
J. R. Mellor ◽  
A. D. Randall
Keyword(s):  
Gabaa Receptors ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
High Concentration ◽  
Concentration Jump ◽  
Cerebellar Granule ◽  
Resistant Population ◽  
S Application ◽  
Stimulation Technique ◽  
Cerebellar Cultures

GABA concentration jump experiments performed on membrane patches predict that postsynaptic GABAAreceptors will become desensitized following the release of the contents of a single GABA-containing synaptic vesicle. To examine this we used a single synaptic bouton stimulation technique to directly examine whether postsynaptic GABAA receptors in cultured cerebellar granule cells exhibit transmitter-induced desensitization. In a large number of recordings, no evidence was found for desensitization of postsynaptic GABAAreceptors by vesicularly released transmitter. This was the case even when as many as 40 vesicles were released from a single bouton within 1.5 s. In addition, postsynaptic depolarization and application of the benzodiazepine flunitrazepam, manipulations previously shown to enhance desensitization of GABAA receptors, failed to unmask transmitter-induced desensitization. In contrast, a single 2- to 3-s application of a high concentration of exogenous GABA was able to depress synaptic responsiveness for up to 70 s. Furthermore, pharmacological depletion of GABA eliminated inhibitory synaptic communication, suggesting that GABA is the transmitter and the desensitization-resistant inhibitory postsynaptic currents are not mediated by a “nondesensitizing” ligand such as β-alanine. Overall our data indicate that a specific desensitization-resistant population of GABAA receptors are present at postsynaptic sites on cultured cerebellar granule cells.

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