Postsynaptic potential and postsynaptic current in muscle fibres with large time-constant. Epsp amplitude is independent of membrane resistance

1982 ◽  
Vol 13 (6) ◽  
pp. 477-484 ◽  
Author(s):  
L. Fischer ◽  
E. Florey
Keyword(s):  
Time Constant ◽  
Large Time ◽  
Membrane Resistance ◽  
Muscle Fibres ◽  
Epsp Amplitude ◽  
Postsynaptic Potential

Structure and electrical properties of eye muscles in cave- and surface-dwelling crayfishes

1980 ◽  
Vol 84 (1) ◽  
pp. 187-199
Author(s):  
D. Mellon ◽  
G. Lnenicka
Keyword(s):  
Input Resistance ◽  
Selective Advantage ◽  
Oculomotor System ◽  
Membrane Resistance ◽  
Muscle Fibres ◽  
Cross Sectional ◽  
Eye Muscles ◽  
Current Voltage ◽  
The Difference ◽  
Cave Dweller

The morphologies and passive electrical parameters of fibres in two eye muscles of a surface- and a cave-dwelling crayfish were compared. In the cave-dwelling form the muscles contained fewer fibres, of less diameter, and hence had a smaller cross-sectional area. Current-voltage relationships were similar in both species. Input resistance was higher in the cave-dweller, but the difference was not as great as would be expected on the basis of geometry alone. Accordingly, the specific membrane resistance of muscle fibres in the cave-dweller is 50–60% smaller than that in the surface-dweller. This may account partially for the observation that identified excitatory junctional potentials in muscles of cave- and surface dwellers have similar amplitudes. We conclude that a functional oculomotor system is maintained in cave-dwelling crayfish, and that this system confers some positive selective advantage.

STUDY ON TIME-CONSTANT MODELS OF SnO2pH SENSOR

2009 ◽  
Vol 21 (06) ◽  
pp. 449-452
Author(s):  
Chi-Wei Chen ◽  
Jung-Chuan Chou ◽  
Tai-Ping Sun ◽  
Shen-Kan Hsiung
Keyword(s):  
Time Constant ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Ph Sensor ◽  
Membrane Resistance ◽  
Hysteresis Effect ◽  
Equivalent Model ◽  
Resistance Change ◽  
Ph Buffer ◽  
Function Relationship

The aim of this study was to discuss the hysteresis effect of SnO2 pH sensor based on separative extended gate field effect transistor (SEGFET). Based on the theorem of three time-constants model, hysteresis model is linked with drift effect. Function relationship of pH value and time constant is also derived from the drift effects with difference pH value. Besides, electrochemical impedance spectroscopy (EIS) is utilized to interpret the mechanism of hysteresis effect. Experiments of EIS are carried out in different pH buffer solutions. An equivalent model of sensing membrane is obtained by theorem of EIS. The experimental results indicate that the equivalent circuit elements, such as membrane capacitance and membrane resistance, change with pH. This phenomenon is compared with other literatures and discussed on hysteresis effect.

Restoration of terahertz continuous wave image obtained by continuous scan mode with large time constant

2014 ◽  
Vol 53 (32) ◽  
pp. 7735 ◽  
Author(s):  
Xiao Lou ◽  
Lei Hou ◽  
Gaoyuan Guo ◽  
Wei Shi
Keyword(s):  
Time Constant ◽  
Large Time ◽  
Continuous Wave ◽  
Wave Image

Thermal acclimation in a crustacean neuromuscular system

1982 ◽  
Vol 98 (1) ◽  
pp. 39-47
Author(s):  
P. J. Stephens ◽  
H. L. Atwood
Keyword(s):  
Membrane Potential ◽  
Muscle Fibre ◽  
Time Constant ◽  
Potential Temperature ◽  
Shore Crab ◽  
Acclimation Temperature ◽  
Muscle Fibres ◽  
Fibre Membrane ◽  
The Pacific ◽  
Different Temperatures

1. Effects of temperature on the muscle fibre membrane and synapses of stretcher muscle preparations made from autotomized limbs of the Pacific shore crab (Pachygrapsus crassipes) were investigated. 2. Acclimation of the crabs to different temperatures modified properties of both muscle fibre membrane and synapses. 3. Increased temperature produced an increase in membrane potential of the muscle fibres. A semi-log plot of these data revealed two linear phases of the membrane potential-temperature relationship, with a change in slope near the acclimation temperature. 4. Maximum values for excitatory junction potential (EJP) amplitude and time constant of EJP decay, and minimum values for facilitation were obtained at temperatures close to the acclimation temperature. It is suggested that the decline in EJP amplitude and time constant of decay produced by deviations in temperature from the acclimation temperature is compensated for by an increase in the amount of facilitation. In this way, maximum tension can be produced by the stretcher muscle in a range of at least 8 degrees C around the acclimation temperature.

Rapid Measurement of Power Transformer Winding DC Resistance

2013 ◽  
Vol 333-335 ◽  
pp. 22-26
Author(s):  
Xiao Fei Luo ◽  
Xian Xia ◽  
Kai Jun Wu
Keyword(s):  
Time Constant ◽  
Large Time ◽  
Power Transformer ◽  
Resistance Mutation ◽  
Transition Process ◽  
Measurement Circuit ◽  
Rapid Measurement ◽  
Transformer Winding ◽  
Simulation Results ◽  
Dc Resistance

Aim at the electric power transformer with inductance is large, resistance is small, the inherent characteristics of the large time constant, a fast measurement scheme of power transformer winding DC resistance is proposed. The scheme adopts the increase the measurement circuit loop resistance mutation method, in which the circuit transition process from a time constant is forced to another time constant, to realize the rapid measurement of winding DC resistance in power transformer. Simulation results show the effectiveness of the scheme.

scholarly journals Adaptation in the Ventral Eye of Limulus is Functionally Independent of the Photochemical Cycle, Membrane Potential, and Membrane Resistance

1973 ◽  
Vol 61 (3) ◽  
pp. 273-289 ◽  
Author(s):  
A. Fein ◽  
R. D. DeVoe
Keyword(s):  
Membrane Potential ◽  
Time Constant ◽  
Dark Adaptation ◽  
Light Adaptation ◽  
Receptor Potential ◽  
Membrane Resistance ◽  
Initial Time ◽  
Early Receptor Potential ◽  
Time Courses ◽  
Sensitivity Changes

The early receptor potential (ERP), membrane potential, membrane resistance, and sensitivity were measured during light and/or dark adaptation in the ventral eye of Limulus. After a bright flash, the ERP amplitude recovered with a time constant of 100 ms, whereas the sensitivity recovered with an initial time constant of 20 s. When a strong adapting light was turned off, the recovery of membrane potential and of membrane resistance had time-courses similar to each other, and both recovered more rapidly than the sensitivity. The receptor depolarization was compared during dark adaptation after strong illumination and during light adaptation with weaker illumination; at equal sensitivities the cell was more depolarized during light adaptation than during dark adaptation. Finally, the waveforms of responses to flashes were compared during dark adaptation after strong illumination and during light adaptation with weaker illumination. At equal sensitivities (equal amplitude responses for identical flashes), the responses during light adaptation had faster time-courses than the responses during dark adaptation. Thus neither the photochemical cycle nor the membrane potential nor the membrane resistance is related to sensitivity changes during dark adaptation in the photoreceptors of the ventral eye. By elimination, these results imply that there are (unknown) intermediate process(es) responsible for adaptation interposed between the photochemical cycle and the electrical properties of the photoreceptor.

Phosphoreszenz der Entladungsrohrwand (Kovarglas) als Beitrag zur Lichtemission abklingender Plasmen

1971 ◽  
Vol 26 (11) ◽  
pp. 1897-1900 ◽  
Author(s):  
T. D. Märk ◽  
H. J. Oskam
Keyword(s):  
Time Constant ◽  
Plasma Volume ◽  
Discharge Tube ◽  
Large Time ◽  
Glass Tube ◽  
Helium Plasma ◽  
Decay Period

Emission having a large time constant has been measured recently in the decay period of plasmas produced in nitrogen and helium-nitrogen mixtures. Whereas the fast decaying emission during the early afterglow originates from the plasma volume, it was suspected that emission responsible for the large time constant (10 to 15 ms) was not due to emission processes involving nitrogen. The present studies relate to detailed measurements of this phenomenon in a decaying helium plasma produced in a Kovarglass built discharge tube. It will be shown that this slow decaying emission is due to phosphorescence of the walls of the glass tube.

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