電気緊張電位
WordNet
- existing in possibility; "a potential problem"; "possible uses of nuclear power" (同)possible
- the inherent capacity for coming into being (同)potentiality, potency
PrepTutorEJDIC
- 可能性のある,潜在的な / 可能性,潜在力 / 電位
Wikipedia preview
出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/05/28 21:33:16」(JST)
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In physiology, electrotonus refers to the passive spread of charge inside a neuron. Passive means that voltage-dependent changes in membrane conductance do not contribute. Neurons and other excitable cells produce two types of electrical potential:
- Electrotonic potential — a non-propagated local potential, resulting from a local change in ionic conductance (e.g. synaptic or sensory that engenders a local current). When it spreads along a stretch of membrane, it becomes exponentially smaller (decrement).
- Action potential — a propagated impulse.
Electrotonic potentials represent changes to the neuron's membrane potential that do not lead to the generation of new current by action potentials.[1] Neurons which are small in relation to their length, such as some neurons in the brain have only electrotonic potentials (starbust amacrine cells in the retina are believed to have these properties); longer neurons utilize electrotonic potentials to trigger the action potential.
The electrotonic potential travels via electrotonic spread, which amounts to attraction of opposite- and repulsion of like-charged ions within the cell. Electrotonic potentials can sum spatially or temporally. Spatial summation is the combination of multiple sources of ion influx (multiple channels within a dendrite, or channels within multiple dendrites), where temporal summation is a gradual increase in overall charge due to repeated influxes in the same location. Because the ionic charge enters in one location and dissipates to others, losing intensity as it spreads, electrotonic spread is a graded response. It is important to contrast this with the all-or-none law propagation of the action potential down the axon of the neuron.
Electrotonic spread is generally responsible for increasing the voltage of the soma (neuronal cell body) sufficiently to exceed threshold and trigger the action potential; its summation properties described above make it suitable for integrating input from many different sources. Such input may be depolarizing (positive charge, such as sodium) or hyperpolarizing (negative charge, such as chloride).
Electrotonic potentials are conducted faster than action potentials, but attenuate rapidly so are unsuitable for long-distance signaling.
See also
- Plateau potentials
- Cable theory
- Bioelectrochemistry
- Voltage-gated ion channel
References
- ^ electrotonic - definition of electrotonic in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia
External links
- Khan Academy: Electrotonic and action potential
UpToDate Contents
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English Journal
- Complex restitution behavior and reentry in a cardiac tissue model for neonatal mice.
- Mayer A1, Bittihn P2, Luther S1,3,4,5,6.
- Physiological reports.Physiol Rep.2017 Oct;5(19). pii: e13449. doi: 10.14814/phy2.13449.
- PMID 28989116
- Induced mitochondrial membrane potential for modeling solitonic conduction of electrotonic signals.
- Poznanski RR1, Cacha LA2, Ali J2, Rizvi ZH2, Yupapin P3,4, Salleh SH5, Bandyopadhyay A6.
- PloS one.PLoS One.2017 Sep 7;12(9):e0183677. doi: 10.1371/journal.pone.0183677. eCollection 2017.
- PMID 28880876
- Electrical coupling between ventricular myocytes and myofibroblasts in the infarcted mouse heart.
- Rubart M1, Tao W1, Lu XL1, Conway SJ1, Reuter SP1, Lin SF2, Soonpaa MH1,3.
- Cardiovascular research.Cardiovasc Res.2017 Sep 1. doi: 10.1093/cvr/cvx163. [Epub ahead of print]
- PMID 29016731
Japanese Journal
- Measurement of the action potential of the nerve for the isolation of the nerve in the operative field: An experimental study in rabbit
- 術中神経探索を目的とした神経活動電位測定のための基礎的研究
- Intracellular Calcium and the Mechanism of the Dip in the Anodal Strength-Interval Curve in Cardiac Tissue
Related Links
- Two different types of changes in the membrane potential of a neuron. ... If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.
- Electrotonic potential — a non-propagated local potential, resulting from a local change in ionic conductance (e.g. synaptic or sensory that engenders a local current). When it spreads along a stretch of membrane, it becomes . [] ...
★リンクテーブル★
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- 英
- electrotonic potential
- 関
- 脱分極、長さ定数
- 静止膜本来の容量と抵抗により、刺激のために注入された電流が引き起こす電位変化 (SP.63)
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過分極性電気緊張電位レベル
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- 関
- capability、capable、electric potential、electrical potential、feasibility、feasible、latently、likelihood、odds、possibility、possible、potentiality、potentially、probability、promising、voltage
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