chronaxie , auch: chronaxy

The published values for chronaxie have a wide range.

The minimum energy occurs with a pulse duration equal to chronaxie.

In addition, the chronaxie value, however determined, identifies the pulse duration for minimum energy.

In addition, the charge delivered at chronaxie, however determined, is 2, twice the minimum charge.

The main value of chronaxie is comparing excitability across different experiments and measurements using the same standard, thus making data comparisons easier.

The x-intercept of the Weiss equation is equal to b x c, or rheobase times chronaxie.

A reduction in chronaxie occurs during reinnervation.

The values of chronaxie of TA muscle measured up to 9-month after sciatectomy.

The chronaxie values for human denervated skeletal muscle ranges from 9.5 to 30 ms at body temperature, representing a ratio of 3.16.

Electrical stimulation based on chronaxie could regulate myoD gene expression in denervated muscle fibers.

Lapicque used constant-current, capacitor-discharge pulses to obtain chronaxie for a wide variety of excitable tissues.

However, the threshold starts increasing with decreasing duration of a pulse (or a cycle) when it drops below a characteristic minimum (so called chronaxie).

The chronaxie times reported for soma and dendrites have been established using intracellular pulses that cannot be readily extrapolated to extra- cellular stimuli.

In 3 out of 36 leg muscles, reinnervation occurred spontaneously and chronaxie shortened to 0.1 ms, which is the value of normal innervated muscle.

Chronaxie remained at this level up to 6 months postsciatectomy (Mid-term denervation stage in the rat model: from 2 to 6 months sciatectomy).

Acute intoxication of rats with aldrin decreases chronaxie, whereas chronic exposure to this chlorinated hydrocarbon insecticide has the reverse effect.

Chronaxie varies across different types of tissue: fast-twitch muscles have a lower chronaxie, slow-twitch muscles have a higher one.

The term chronaxie and rheobase were first coined in Louis Lapicque's famous paper on D'efinition exp'erimentale de l'excitabilit 'e that was published in 1909.

The strength-duration time constant (chronaxie) and rheobase are parameters that describe the strength-duration curve-the curve that relates the intensity of a threshold stimulus to its duration.

To assess contractility of denervated leg muscles, rheobase and chronaxie were determined in anaesthetized rat by surface electrical stimulation and palpation of the leg muscles.

Afterwards, the twitch contraction became questionably palpable and thus chronaxie increased to much longer values (from 50 ms to infinitum, i.e., the muscle twitch was not palpable).

Chronaxie values increase resulting from hyperventilation can be ascribed to a change in skin impedance, the physiological factors responsible for this change being under the influence of the autonomic nervous system.

This example of the preponderating influence which the condition of the skin and the underlying tissues may exert compels caution in judging the results of chronaxie measurements by percutaneous stimulation.

Despite this limitation, Weiss's equation provides the best fit for strength-duration data and indicates that rheobase and time constant (chronaxie) can be measured from the charge duration curve with a very small margin of error.

If chronaxie is the best descriptor of tissue excitability in a homogeneous tissue specimen, at a known temperature, it should be determined with a constant-current stimulator providing a rectangular cathodal stimulus waveform.