Depolarization

(redirected from Depolarizations)
Also found in: Dictionary, Thesaurus, Medical.

depolarization

[dē‚pō·lə·rə′zā·shən]
(electricity)
The removal or prevention of polarization in a substance (for example, through the use of a depolarizer in an electric cell) or of polarization arising from the field due to the charges induced on the surface of a dielectric when an external field is applied.
(optics)
The resolution of polarized light in an optical depolarizer.

Depolarization

 

the decrease in the difference in potentials during the resting state (so-called resting potential) between the internal and external sides of the membrane of a living cell. In nerve cells and their processes, as well as in muscle fibers, depolarization is one of the most important components of the process of excitation. Stable depolarization may occur experimentally or in certain diseases as a result of direct damage to the membrane or disruption of metabolism.

References in periodicals archive ?
Besides, the inhibition of the mitochondrial respiratory chain described above by decavanadate can lead to sustained mitochondrial depolarization which is lethal for cells demanding a high supply of metabolic energy.
It is known that mitochondrial membrane depolarization leads to mitochondrial calcium release [35] and also I[P.
Delayed ischaemic neurological deficits after subarachnoid haemorrhage are associated with clusters of spreading depolarizations.
Repetitive cortical spreading depolarizations in a case of severe brain trauma.
3A): the soma recording shows a sustained, slow depolarization (i.
If the neuron is relatively undamaged (as evidenced by high input resistance and a resting potential ~-50 mV), depolarization to a threshold (~-45 mV) initiates a regenerative response requiring 10 or more ms to reach a maximum ~20 mV depolarized from resting potential (Fig.
The field was removed and the depolarization current monitored as the temperature was increased.
Relationships have been developed th at attempt to calculate actual TSDC frequencies using this correlation, as well as correlations that exist with other known quantities, such as [delta]H (activation energy of the depolarization process), and various Williams-Landel-Ferry (WLF) fitting parameters [3].
Application of GABA to spontaneously oscillating muscle fibers produced a biphasic response: an initial period of membrane hyperpolarization and decreased oscillation frequency, followed by a period of increased frequency of spontaneous depolarizations.
Although the lack of a self-maintained depolarization in APR and another unidentified motoneuron does not rule out the existence of endogenous bursting mechanisms in these cells, it does suggest that the rhythm is, in part, synaptically driven by premotor interneurons.
The fast sodium channels are responsible for the rapid depolarization (phase 0) of fast-response cardiac action potentials.
Changes in inward cationic currents might also contribute to EADs, slow response APs during depolarization and transient inward currents (Iti) on repolarization (5).