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图注：''Key'': {{fontcolor|blue|Blue}} 五边形——钠离子；{{fontcolor|purple|Purple}} 正方形——钾离子；{{fontcolor|yellow|gray|Yellow}} 圆形——氯离子；{{fontcolor|darkorange|Orange}} 矩形——膜不通透的阴离子（它们来源广泛，包括蛋白质）。带箭头的大 {{fontcolor|purple|purple}} 的结构表示跨膜钾离子通道和钾离子的净流动方向。|链接=Special:FilePath/Basis_of_Membrane_Potential2.png]]

图注：''Key'': {{fontcolor|blue|Blue}} 五边形——钠离子；{{fontcolor|purple|Purple}} 正方形——钾离子；{{fontcolor|yellow|gray|Yellow}} 圆形——氯离子；{{fontcolor|darkorange|Orange}} 矩形——膜不通透的阴离子（它们来源广泛，包括蛋白质）。带箭头的大 {{fontcolor|purple|purple}} 的结构表示跨膜钾离子通道和钾离子的净流动方向。|链接=Special:FilePath/Basis_of_Membrane_Potential2.png]]

'''Membrane potential''' (also '''transmembrane potential''' or '''membrane voltage''') is the difference in [[electric potential]] between the interior and the exterior of a biological [[Cell (biology)|cell]]. That is, there is a difference in the energy required for electric charges to move from the internal to exterior cellular environments and vice versa, as long as there is no acquisition of kinetic energy or the production of radiation. The concentration gradients of the charges directly determine this energy requirement. For the exterior of the cell, typical values of membrane potential, normally given in units of [[milli]][[volt]]s and denoted as mV, range from –80 mV to –40 mV.

膜电位（也叫跨膜电位或膜电压）是生物细胞内部和外部的电位差。也就是说，只要没有获得动能或产生辐射，电荷从细胞内环境移动到细胞外环境与从外部移动内部所需的能量是不同的。电荷的浓度梯度直接决定这种能量要求。相对细胞外部，典型的膜电位值，通常以毫伏（表示为 mV）为单位，处于 -80 mV 到 -40 mV 的范围。

几乎所有的细胞质膜都存在一个跨膜电位，内部通常相对于外部是负电位 <ref name=":0">{{Cite book|title=Molecular biology of the cell|last=Bruce|first=Alberts|isbn=9780815344322|edition=Sixth|location=New York, NY|oclc=887605755|date = 2014-11-18}}</ref>。膜电位有两个基本功能。首先，它允许细胞像电池一样工作，提供动力来操作嵌在膜中的各种“分子设备”<ref name=":1">{{Cite journal|last1=Abdul Kadir|first1=Lina|last2=Stacey|first2=Michael|last3=Barrett-Jolley|first3=Richard|date=2018|title=Emerging Roles of the Membrane Potential: Action Beyond the Action Potential|journal=Frontiers in Physiology|language=English|volume=9|doi=10.3389/fphys.2018.01661|pmid=30519193|issn=1664-042X|doi-access=free}}</ref> 。其次，在神经元和肌肉细胞等电兴奋性细胞中，它可用来在细胞的不同部位之间传递信号。信号是通过在膜的某一点打开或关闭离子通道而产生的，从而引起膜电位的局部变化。这种电场的变化可以被膜上相邻或更远的离子通道迅速检测到。这些离子通道可以随着电位的变化而打开或关闭，重新产生信号。

 

 

Almost all plasma membranes have an electrical potential across them, with the inside usually negative with respect to the outside.<ref name=":0">{{Cite book|title=Molecular biology of the cell|last=Bruce|first=Alberts|isbn=9780815344322|edition=Sixth|location=New York, NY|oclc=887605755|date = 2014-11-18}}</ref> The membrane potential has two basic functions. First, it allows a cell to function as a battery, providing power to operate a variety of "molecular devices" embedded in the membrane.<ref name=":1">{{Cite journal|last1=Abdul Kadir|first1=Lina|last2=Stacey|first2=Michael|last3=Barrett-Jolley|first3=Richard|date=2018|title=Emerging Roles of the Membrane Potential: Action Beyond the Action Potential|journal=Frontiers in Physiology|language=English|volume=9|doi=10.3389/fphys.2018.01661|pmid=30519193|issn=1664-042X|doi-access=free}}</ref> Second, in electrically '''excitable cells''' such as [[neuron]]s and [[myocyte|muscle cells]], it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly sensed by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change, reproducing the signal.

 

In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the [[resting potential]]. For neurons, resting potential is defined as ranging from –80 to –70 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a [[depolarization]] if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a [[hyperpolarization (biology)|hyperpolarization]] if the interior voltage becomes more negative (say from –70 mV to –80 mV).  In excitable cells, a sufficiently large depolarization can evoke an [[action potential]], in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity.  Action potentials are generated by the activation of certain [[voltage-gated ion channel]]s.

In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the [[resting potential]]. For neurons, resting potential is defined as ranging from –80 to –70 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a [[depolarization]] if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a [[hyperpolarization (biology)|hyperpolarization]] if the interior voltage becomes more negative (say from –70 mV to –80 mV).  In excitable cells, a sufficiently large depolarization can evoke an [[action potential]], in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity.  Action potentials are generated by the activation of certain [[voltage-gated ion channel]]s.

在不可兴奋的细胞以及处于基线状态的可兴奋细胞中，膜电位保持在一个相对稳定的值，称为静息电位。对于神经元，静息电位的定义为-80到-70毫伏; 也就是说，细胞内部的负基线电压略低于十分之一伏特。离子通道的开启和关闭可以导致静息电位的偏离。如果内部电压变得不那么负(比如从-70 mV 到-60 mV) ，这就叫去极化; 如果内部电压变得更负(比如从-70 mV 到-80 mV) ，这就叫去极化超极化。在可兴奋的细胞中，足够大去极化可以激发动作电位，在这个动作电位中，膜电位在短时间内迅速而显著地改变(大约1到100毫秒) ，经常反转其极性。动作电位是通过激活某些电压门控离子通道而产生的。

在非兴奋性细胞以及处于基线状态的兴奋性细胞，膜电位保持在一个相对稳定的值，称为静息电位。对于神经元，静息电位的定义为 -80 到 -70 mV；也就是说，细胞内部的负基线电压略低于十分之一伏特。离子通道的开启和关闭可以导致静息电位的偏离。如果内部电压变得不那么负(比如从-70 mV 到-60 mV) ，这就叫去极化; 如果内部电压变得更负(比如从-70 mV 到-80 mV) ，这就叫去极化超极化。在可兴奋的细胞中，足够大去极化可以激发动作电位，在这个动作电位中，膜电位在短时间内迅速而显著地改变(大约1到100毫秒) ，经常反转其极性。动作电位是通过激活某些电压门控离子通道而产生的。

In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.

In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.

其中  

其中  

*Eeq，k + 是钾的平衡电位，用伏特

*''E''_eq,K⁺ 是钾的平衡电位，用伏特为单位

*r 表示万能气体常数，等于8.314焦耳 k-1 mol-1

*''R'' 为通用气体常数，等于  8.314 [[joule]]s·K⁻¹·mol⁻¹

*t 是绝对温度，用 k = 摄氏度 + 273.15)

*''T''  为绝对温度，以 K 为单位 in [[kelvin]]s (= K = degrees Celsius + 273.15)

* z 表示反应中所涉及的离子的基本电荷数

*''z''  反应中所涉及的离子的基本电荷数

*f 是法拉第常数，等于96,485coulombsmol-1或 jv-1mol-1[ k + ] o 为细胞外钾离子浓度，在 mol-3或 mmol l-1[ k + ] i 为细胞内钾离子浓度

*''F''  是法拉第常数，等于  96,485 [[coulomb]]s·mol⁻¹  is the [[Faraday constant]], equal to 96,485 [[coulomb]]s·mol⁻¹ or J·V⁻¹·mol⁻¹

*[K⁺]_o 为钾离子的胞外浓度 measured in [[Mole (unit)|mol]]·m⁻³ or mmol·l⁻¹

*[K⁺]_i is 为钾离子的胞内浓度，

Even if two different ions have the same charge (i.e., K⁺ and Na⁺), they can still have very different equilibrium potentials, provided their outside and/or inside concentrations differ. Take, for example, the equilibrium potentials of potassium and sodium in neurons. The potassium equilibrium potential ''E''_K is −84&nbsp;mV with 5&nbsp;mM potassium outside and 140&nbsp;mM inside. On the other hand, the sodium equilibrium potential,  ''E''_Na, is approximately +66&nbsp;mV with approximately 12 mM sodium inside and 140 mM outside.<ref group="note" name=":0">Note that the signs of ''E''_Na and ''E''_K are opposite. This is because the concentration gradient for potassium is directed out of the cell, while the concentration gradient for sodium is directed into the cell. Membrane potentials are defined relative to the exterior of the cell; thus, a potential of −70&nbsp;mV implies that the interior of the cell is negative relative to the exterior.</ref>

即使两种离子具有相同的电荷（即 K⁺ and Na⁺ ），只要胞内外浓度不同，它们仍然具有非常不同的平衡电位。以神经元中钾和钠的平衡电位为例，钾离子在胞内为 140 mM，胞外 5 mM，平衡电位为 -84 mV；而钠离子胞内约 12 mM，胞外 140 mM，平衡电位 ''E''_Na 约为 +66 mV <ref name=":0" group="note">Note that the signs of ''E''_Na and ''E''_K are opposite. This is because the concentration gradient for potassium is directed out of the cell, while the concentration gradient for sodium is directed into the cell. Membrane potentials are defined relative to the exterior of the cell; thus, a potential of −70&nbsp;mV implies that the interior of the cell is negative relative to the exterior.</ref>。

即使两种不同的离子具有相同的电荷(即 k + 和 Na +) ，只要它们的外部和/或内部浓度不同，它们仍然具有非常不同的平衡电位。以神经元中钾和钠的平衡电位为例。钾平衡电位为 -84mv，内含140mm 的钾，外含5mm 的钾。另一方面，钠平衡电位，ENa，约为 + 66mv，内部约为12mm 钠，外部约为140mm.<ref name=":0" group="note" />。

===发育中膜电位的变化===

 

===Changes to membrane potential during development===

A [[neuron]]'s resting membrane potential actually changes during the [[Neural development|development]] of an organism. In order for a neuron to eventually adopt its full adult function, its potential must be tightly regulated during development. As an organism progresses through development the resting membrane potential becomes more negative.<ref name=":7">{{Cite journal|last1=Sanes|first1=Dan H.|last2=Takács|first2=Catherine|date=1993-06-01|title=Activity-dependent Refinement of Inhibitory Connections|journal=European Journal of Neuroscience|language=en|volume=5|issue=6|pages=570–574|doi=10.1111/j.1460-9568.1993.tb00522.x|pmid=8261131|s2cid=30714579|issn=1460-9568}}</ref> [[Neuroglia|Glial cells]] are also differentiating and proliferating as development progresses in the [[brain]].<ref name=":8">{{Cite journal|last1=KOFUJI|first1=P.|last2=NEWMAN|first2=E. A.|date=2004-01-01|journal=Neuroscience|volume=129|issue=4|pages=1045–1056|doi=10.1016/j.neuroscience.2004.06.008|issn=0306-4522| pmc=2322935 |pmid=15561419|title=Potassium buffering in the central nervous system}}</ref> The addition of these glial cells increases the organism's ability to regulate extracellular [[potassium]]. The drop in extracellular potassium can lead to a decrease in membrane potential of 35 mV.<ref name=":9">{{Cite book|title=Development of the nervous system|last1=Sanes|first1=Dan H.|last2=Reh|first2=Thomas A|date=2012-01-01|publisher=Elsevier Academic Press|isbn=9780080923208|pages=211–214|oclc=762720374|edition=Third}}</ref>

A [[neuron]]'s resting membrane potential actually changes during the [[Neural development|development]] of an organism. In order for a neuron to eventually adopt its full adult function, its potential must be tightly regulated during development. As an organism progresses through development the resting membrane potential becomes more negative.<ref name=":7">{{Cite journal|last1=Sanes|first1=Dan H.|last2=Takács|first2=Catherine|date=1993-06-01|title=Activity-dependent Refinement of Inhibitory Connections|journal=European Journal of Neuroscience|language=en|volume=5|issue=6|pages=570–574|doi=10.1111/j.1460-9568.1993.tb00522.x|pmid=8261131|s2cid=30714579|issn=1460-9568}}</ref> [[Neuroglia|Glial cells]] are also differentiating and proliferating as development progresses in the [[brain]].<ref name=":8">{{Cite journal|last1=KOFUJI|first1=P.|last2=NEWMAN|first2=E. A.|date=2004-01-01|journal=Neuroscience|volume=129|issue=4|pages=1045–1056|doi=10.1016/j.neuroscience.2004.06.008|issn=0306-4522| pmc=2322935 |pmid=15561419|title=Potassium buffering in the central nervous system}}</ref> The addition of these glial cells increases the organism's ability to regulate extracellular [[potassium]]. The drop in extracellular potassium can lead to a decrease in membrane potential of 35 mV.<ref name=":9">{{Cite book|title=Development of the nervous system|last1=Sanes|first1=Dan H.|last2=Reh|first2=Thomas A|date=2012-01-01|publisher=Elsevier Academic Press|isbn=9780080923208|pages=211–214|oclc=762720374|edition=Third}}</ref>

= = = 发育过程中膜电位的变化神经元的静息膜电位在生物体发育过程中实际上发生了变化。为了让一个神经元最终发挥其完整的成年功能，它的潜能必须在发育过程中受到严格的调控。随着生物体的发育，静息膜电位变得更加消极.<ref name=":7" /> 。随着脑的发育，神经胶质细胞也在分化和增殖.<ref name=":8" />。这些神经胶质细胞的加入增加了机体调节细胞外钾的能力。细胞外液中的钾下降可以导致膜电位下降35mv.<ref name=":9" />。

神经元的静息膜电位在生物体发育过程中会发生变化。为了让神经元最终发挥其完整的成年期功能，它的潜能必须在发育过程中受到严格的调控。随着生物体的发育，静息膜电位变得更负 <ref name=":7" /> 。随着脑的发育，神经胶质细胞也在分化和增殖 <ref name=":8" />。增加的神经胶质细胞增加了机体调节细胞外钾的能力。细胞外液中的钾的下降可导致膜电位下降 35 mV <ref name=":9" />。

=== Cell excitability===

=== 细胞兴奋性===

{{Further|Excitable medium}}

细胞兴奋性（Cell excitability）是各种组织中的细胞反应所必需的细胞膜电位变化。细胞兴奋性是早期胚胎发生过程中诱导的一种特性 <ref name=":10">{{Cite journal|last=Tosti|first=Elisabetta|date=2010-06-28|title=Dynamic roles of ion currents in early development|journal=Molecular Reproduction and Development|volume=77|issue=10|pages=856–867|doi=10.1002/mrd.21215|pmid=20586098|s2cid=38314187|issn=1040-452X|doi-access=free}}</ref>。细胞兴奋性也被定义为引起反应的容易程度 <ref name=":11">{{Cite journal|last1=Boyet|first1=M.R.|last2=Jewell|first2=B.R.|date=1981|title=Analysis of the effects of changes in rate and rhythm upon electrical activity in the heart|journal=Progress in Biophysics and Molecular Biology|volume=36|issue=1|pages=1–52|doi=10.1016/0079-6107(81)90003-1|pmid=7001542|issn=0079-6107|doi-access=free}}</ref> 。静息电位和阈电位是细胞兴奋性的基础，这些过程是细胞剂量电位和动作电位产生的基础。

细胞兴奋性最重要的调节因子是细胞外电解质浓度（即 Na⁺, K⁺, [[Calcium metabolism|Ca²⁺]], Cl⁻, [[Magnesium in biology|Mg²⁺]]）及其相关蛋白。调节细胞兴奋性的重要蛋白质是电压门控离子通道、离子转运蛋白（如钠钾 ATP 酶、镁转运蛋白、酸碱转运蛋白）、膜受体和超极化激活的环核苷酸门控通道 <ref name=":12">{{Cite journal|last1=Spinelli|first1=Valentina|last2=Sartiani|first2=Laura|last3=Mugelli|first3=Alessandro|last4=Romanelli|first4=Maria Novella|last5=Cerbai|first5=Elisabetta|date=2018|title=Hyperpolarization-activated cyclic-nucleotide-gated channels: pathophysiological, developmental, and pharmacological insights into their function in cellular excitability|journal=Canadian Journal of Physiology and Pharmacology|volume=96|issue=10|pages=977–984|doi=10.1139/cjpp-2018-0115|pmid=29969572|issn=0008-4212|hdl=1807/90084|hdl-access=free}}</ref>。例如，钾离子通道和钙敏感受体是神经元、心肌细胞和星形胶质细胞等其他兴奋性细胞的兴奋性的重要调节因子<ref name=":13">{{Cite journal|last1=Jones|first1=Brian L.|last2=Smith|first2=Stephen M.|date=2016-03-30|title=Calcium-Sensing Receptor: A Key Target for Extracellular Calcium Signaling in Neurons|journal=Frontiers in Physiology|volume=7|page=116|doi=10.3389/fphys.2016.00116|pmid=27065884|pmc=4811949|issn=1664-042X|doi-access=free}}</ref> 。钙离子也是可兴奋细胞信号转导中最重要的第二信使。突触受体的激活产生神经元兴奋性的长期改变 <ref name=":14">{{Cite journal|last1=Debanne|first1=Dominique|last2=Inglebert|first2=Yanis|last3=Russier|first3=Michaël|date=2019|title=Plasticity of intrinsic neuronal excitability|journal=Current Opinion in Neurobiology|language=en|volume=54|pages=73–82|doi=10.1016/j.conb.2018.09.001|pmid=30243042|s2cid=52812190|url=https://hal-amu.archives-ouvertes.fr/hal-01963474/file/Debannne-Russier-2019.pdf}}</ref>。甲状腺激素、肾上腺激素和其他激素也调节细胞的兴奋性，例如，孕酮和雌激素调节子宫平滑肌细胞的兴奋性。

 

 

The most important [[Homeostasis|regulators]] of cell excitability are the extracellular [[electrolyte]] concentrations (i.e. Na⁺, K⁺, [[Calcium metabolism|Ca²⁺]], Cl⁻, [[Magnesium in biology|Mg²⁺]]) and associated proteins. Important proteins that regulate cell excitability are [[voltage-gated ion channel]]s, [[ion transporter]]s (e.g. [[Na+/K+-ATPase]], [[magnesium transporter]]s, [[Acid–base homeostasis|acid–base transporters]]), [[Receptor (biochemistry)|membrane receptors]] and [[HCN channel|hyperpolarization-activated cyclic-nucleotide-gated channels]].<ref name=":12">{{Cite journal|last1=Spinelli|first1=Valentina|last2=Sartiani|first2=Laura|last3=Mugelli|first3=Alessandro|last4=Romanelli|first4=Maria Novella|last5=Cerbai|first5=Elisabetta|date=2018|title=Hyperpolarization-activated cyclic-nucleotide-gated channels: pathophysiological, developmental, and pharmacological insights into their function in cellular excitability|journal=Canadian Journal of Physiology and Pharmacology|volume=96|issue=10|pages=977–984|doi=10.1139/cjpp-2018-0115|pmid=29969572|issn=0008-4212|hdl=1807/90084|hdl-access=free}}</ref> For example, [[potassium channels]] and [[calcium-sensing receptor]]s are important regulators of excitability in [[neurons]], [[cardiac myocytes]] and many other excitable cells like [[astrocytes]].<ref name=":13">{{Cite journal|last1=Jones|first1=Brian L.|last2=Smith|first2=Stephen M.|date=2016-03-30|title=Calcium-Sensing Receptor: A Key Target for Extracellular Calcium Signaling in Neurons|journal=Frontiers in Physiology|volume=7|page=116|doi=10.3389/fphys.2016.00116|pmid=27065884|pmc=4811949|issn=1664-042X|doi-access=free}}</ref> Calcium ion is also the most important [[Second messenger system|second messenger]] in excitable [[cell signaling]]. Activation of synaptic receptors initiates [[Neuroplasticity|long-lasting changes]] in neuronal excitability.<ref name=":14">{{Cite journal|last1=Debanne|first1=Dominique|last2=Inglebert|first2=Yanis|last3=Russier|first3=Michaël|date=2019|title=Plasticity of intrinsic neuronal excitability|journal=Current Opinion in Neurobiology|language=en|volume=54|pages=73–82|doi=10.1016/j.conb.2018.09.001|pmid=30243042|s2cid=52812190|url=https://hal-amu.archives-ouvertes.fr/hal-01963474/file/Debannne-Russier-2019.pdf}}</ref> [[thyroid hormones|Thyroid]], [[Adrenal gland|adrenal]] and other hormones also regulate cell excitability, for example, [[progesterone]] and [[estrogen]] modulate [[myometrial smooth muscle cell]] excitability.

 

Many cell types are considered to have an excitable membrane. Excitable cells are neurons, myocytes (cardiac, skeletal, [[Smooth muscle|smooth]]), vascular [[Endothelium|endothelial cells]], [[pericyte]]s, [[juxtaglomerular cell]]s, [[Interstitial cell of Cajal|interstitial cells of Cajal]], many types of [[Epithelium|epithelial cells]] (e.g. [[beta cell]]s, [[alpha cell]]s, [[delta cell]]s, [[enteroendocrine cell]]s, [[Neuroendocrine_cell#Pulmonary_neuroendocrine_cells|pulmonary neuroendocrine cells]], [[pinealocyte]]s), [[glia]]l cells (e.g. astrocytes), [[mechanoreceptor]] cells (e.g. [[hair cell]]s and [[Merkel cell]]s), [[chemoreceptor]] cells (e.g. [[glomus cell]]s, [[taste receptor]]s), some [[plant cells]] and possibly [[White blood cell|immune cells]].<ref name=":15">{{Cite journal|last1=Davenport|first1=Bennett|last2=Li|first2=Yuan|last3=Heizer|first3=Justin W.|last4=Schmitz|first4=Carsten|last5=Perraud|first5=Anne-Laure|date=2015-07-23|title=Signature Channels of Excitability no More: L-Type Channels in Immune Cells|journal=Frontiers in Immunology|volume=6|page=375|doi=10.3389/fimmu.2015.00375|pmid=26257741|pmc=4512153|issn=1664-3224|doi-access=free}}</ref> Astrocytes display a form of non-electrical excitability based on intracellular calcium variations related to the expression of several receptors through which they can detect the synaptic signal. In neurons, there are different membrane properties in some portions of the cell, for example, dendritic excitability endows neurons with the capacity for coincidence detection of spatially separated inputs.<ref name=":16">{{Cite journal|last=Sakmann|first=Bert|date=2017-04-21|title=From single cells and single columns to cortical networks: dendritic excitability, coincidence detection and synaptic transmission in brain slices and brains|journal=Experimental Physiology|volume=102|issue=5|pages=489–521|doi=10.1113/ep085776|pmid=28139019|pmc=5435930|issn=0958-0670|doi-access=free}}</ref>

Many cell types are considered to have an excitable membrane. Excitable cells are neurons, myocytes (cardiac, skeletal, [[Smooth muscle|smooth]]), vascular [[Endothelium|endothelial cells]], [[pericyte]]s, [[juxtaglomerular cell]]s, [[Interstitial cell of Cajal|interstitial cells of Cajal]], many types of [[Epithelium|epithelial cells]] (e.g. [[beta cell]]s, [[alpha cell]]s, [[delta cell]]s, [[enteroendocrine cell]]s, [[Neuroendocrine_cell#Pulmonary_neuroendocrine_cells|pulmonary neuroendocrine cells]], [[pinealocyte]]s), [[glia]]l cells (e.g. astrocytes), [[mechanoreceptor]] cells (e.g. [[hair cell]]s and [[Merkel cell]]s), [[chemoreceptor]] cells (e.g. [[glomus cell]]s, [[taste receptor]]s), some [[plant cells]] and possibly [[White blood cell|immune cells]].<ref name=":15">{{Cite journal|last1=Davenport|first1=Bennett|last2=Li|first2=Yuan|last3=Heizer|first3=Justin W.|last4=Schmitz|first4=Carsten|last5=Perraud|first5=Anne-Laure|date=2015-07-23|title=Signature Channels of Excitability no More: L-Type Channels in Immune Cells|journal=Frontiers in Immunology|volume=6|page=375|doi=10.3389/fimmu.2015.00375|pmid=26257741|pmc=4512153|issn=1664-3224|doi-access=free}}</ref> Astrocytes display a form of non-electrical excitability based on intracellular calcium variations related to the expression of several receptors through which they can detect the synaptic signal. In neurons, there are different membrane properties in some portions of the cell, for example, dendritic excitability endows neurons with the capacity for coincidence detection of spatially separated inputs.<ref name=":16">{{Cite journal|last=Sakmann|first=Bert|date=2017-04-21|title=From single cells and single columns to cortical networks: dendritic excitability, coincidence detection and synaptic transmission in brain slices and brains|journal=Experimental Physiology|volume=102|issue=5|pages=489–521|doi=10.1113/ep085776|pmid=28139019|pmc=5435930|issn=0958-0670|doi-access=free}}</ref>

许多细胞类型被认为具有可兴奋的膜。可兴奋细胞包括神经元、心肌细胞(心肌细胞、骨骼肌细胞、光滑细胞)、血管内皮细胞、周细胞、肾小球旁细胞、 Cajal 间质细胞、许多类型的上皮细胞(如:。Β 细胞、 α 细胞、 delta 细胞、肠内分泌细胞、肺神经内分泌细胞、松果体细胞等。星形胶质细胞)、机械力受体细胞(例如:。毛细胞和默克尔细胞) ，化学感受器细胞(例如:。血管球细胞，味觉受体) ，一些植物细胞，可能还有免疫细胞.<ref name=":15" />。星形胶质细胞表现出一种非电兴奋性，这种兴奋性是基于细胞内钙离子的变化，这种变化与几个受体的表达有关，通过这些受体它们可以检测到突触信号。在神经元中，细胞的某些部分具有不同的膜特性，例如，树突的兴奋性赋予神经元对空间分离的输入信号进行符合检测的能力s.<ref name=":16" />。

许多细胞类型被认为具有兴奋性膜。兴奋性细胞包括神经元、肌细胞（心肌细胞、骨骼肌细胞、平滑肌细胞）、血管内皮细胞、周细胞、肾小球旁细胞、Cajal 间质细胞、多种类型的上皮细胞（如 β 细胞、α 细胞、δ 细胞、肠内分泌细胞、肺神经内分泌细胞、松果体细胞）、胶质细胞（例如星形胶质细胞）、机械感觉受体细胞（例如毛细胞和 Merkel 细胞）、化学感觉受体细胞（例如血管球细胞、味觉受体细胞）、一些植物细胞，可能还有免疫细胞 <ref name=":15" />。星形胶质细胞表现出一种非电兴奋性，这种兴奋性是基于细胞内钙离子的变化，这种变化与几个受体的表达有关，通过这些受体它们可以检测到突触信号。在神经元中，细胞的某些部分具有不同的膜特性，例如，树突的兴奋性赋予神经元对空间上分离的输入信号进行重合检测的能力 <ref name=":16" />。

===Equivalent circuit===

===Equivalent circuit等效电路===

[[File:Cell membrane equivalent circuit.svg|thumb|right|350px|Equivalent circuit for a patch of membrane, consisting of a fixed capacitance in parallel with four pathways each containing a battery in series with a variable conductance膜片的等效电路，由固定电容组成，并联四条通路，每条通路串联一个电池，电导率可变。|链接=Special:FilePath/Cell_membrane_equivalent_circuit.svg]]

[[File:Cell membrane equivalent circuit.svg|thumb|right|350px|Equivalent circuit for a patch of membrane, consisting of a fixed capacitance in parallel with four pathways each containing a battery in series with a variable conductance膜片的等效电路，由固定电容组成，并联四条通路，每条通路串联一个电池，电导率可变。|链接=Special:FilePath/Cell_membrane_equivalent_circuit.svg]]

Electrophysiologists model the effects of ionic concentration differences, ion channels, and membrane capacitance in terms of an [[equivalent circuit]], which is intended to represent the electrical properties of a small patch of membrane.  The equivalent circuit consists of a capacitor in parallel with four pathways each consisting of a battery in series with a variable conductance.  The capacitance is determined by the properties of the lipid bilayer, and is taken to be fixed.  Each of the four parallel pathways comes from one of the principal ions, sodium, potassium, chloride, and calcium.  The voltage of each ionic pathway is determined by the concentrations of the ion on each side of the membrane; see the [[Membrane potential#Reversal potential|Reversal potential]] section above.  The conductance of each ionic pathway at any point in time is determined by the states of all the ion channels that are potentially permeable to that ion, including leakage channels, ligand-gated channels, and voltage-gated ion channels.

Electrophysiologists model the effects of ionic concentration differences, ion channels, and membrane capacitance in terms of an [[equivalent circuit]], which is intended to represent the electrical properties of a small patch of membrane.  The equivalent circuit consists of a capacitor in parallel with four pathways each consisting of a battery in series with a variable conductance.  The capacitance is determined by the properties of the lipid bilayer, and is taken to be fixed.  Each of the four parallel pathways comes from one of the principal ions, sodium, potassium, chloride, and calcium.  The voltage of each ionic pathway is determined by the concentrations of the ion on each side of the membrane; see the [[Membrane potential#Reversal potential|Reversal potential]] section above.  The conductance of each ionic pathway at any point in time is determined by the states of all the ion channels that are potentially permeable to that ion, including leakage channels, ligand-gated channels, and voltage-gated ion channels.

突触后电位是兴奋性电位还是抑制性电位取决于该电流离子的翻转电位，以及细胞激发动作电位的阈值(大约-50mV)。如果突触后电流超过阈值，如典型的钠离子电流，则被认为是兴奋性的。翻转电位。低于阈值的翻转电位，如典型的 k + 电流，被认为是抑制电流。一个翻转电位高于静息电位阈值但低于阈值的电流本身不会引起动作电位，但是会产生阈值以下的膜电位振荡。因此，作用于开放 Na + 通道的神经递质产生兴奋性突触后电位(epsp) ，而作用于开放 k + 或 Cl-通道的神经递质通常产生抑制性突触后电位(ipsp)。当多种类型的通道在同一时间段内开放时，它们的突触后电位相加。

突触后电位是兴奋性电位还是抑制性电位取决于该电流离子的翻转电位，以及细胞激发动作电位的阈值(大约-50mV)。如果突触后电流超过阈值，如典型的钠离子电流，则被认为是兴奋性的。翻转电位。低于阈值的翻转电位，如典型的 k + 电流，被认为是抑制电流。一个翻转电位高于静息电位阈值但低于阈值的电流本身不会引起动作电位，但是会产生阈值以下的膜电位振荡。因此，作用于开放 Na + 通道的神经递质产生兴奋性突触后电位(epsp) ，而作用于开放 k + 或 Cl-通道的神经递质通常产生抑制性突触后电位(ipsp)。当多种类型的通道在同一时间段内开放时，它们的突触后电位相加。

==Other values==

==Other values 其他值==

#离子的驱动力

#离子的渗透性

# That ion's permeability

 

从生物物理学的观点来看，休眠膜电位仅仅是细胞休眠时主要的细胞膜通透性所产生的膜电位。上面的加权平均数等式总是适用的，但是下面的方法可能更容易可视化。在任何给定的时刻，有两个因素决定了离子对细胞膜电位的影响: # #

 

*'''Driving force''' is the net electrical force available to move that ion across the membrane.  It is calculated as the difference between the voltage that the ion "wants" to be at (its equilibrium potential) and the actual membrane potential (''E''_m). So, in formal terms, the driving force for an ion = ''E''_m - ''E''_ion

*'''Driving force''' is the net electrical force available to move that ion across the membrane.  It is calculated as the difference between the voltage that the ion "wants" to be at (its equilibrium potential) and the actual membrane potential (''E''_m). So, in formal terms, the driving force for an ion = ''E''_m - ''E''_ion

离子越多，预测膜电位就越复杂。然而，这可以用 Goldman-Hodgkin-Katz 方程或加权平均数方程来实现。通过在任意时刻输入离子的浓度梯度和渗透率，就可以在那个时刻测定膜电位。方程的意思是，在任何时候，膜电位的值都是所有离子平衡势的加权平均数。“权重”是离子在膜上的相对渗透性。

离子越多，预测膜电位就越复杂。然而，这可以用 Goldman-Hodgkin-Katz 方程或加权平均数方程来实现。通过在任意时刻输入离子的浓度梯度和渗透率，就可以在那个时刻测定膜电位。方程的意思是，在任何时候，膜电位的值都是所有离子平衡势的加权平均数。“权重”是离子在膜上的相对渗透性。

==Effects and implications==

==Effects and implications 效应与意义==

While cells expend energy to transport ions and establish a transmembrane potential, they use this potential in turn to transport other ions and metabolites such as sugar. The transmembrane potential of the [[mitochondrial membrane|mitochondria]] drives the production of [[Adenosine triphosphate|ATP]], which is the common currency of biological energy.

While cells expend energy to transport ions and establish a transmembrane potential, they use this potential in turn to transport other ions and metabolites such as sugar. The transmembrane potential of the [[mitochondrial membrane|mitochondria]] drives the production of [[Adenosine triphosphate|ATP]], which is the common currency of biological energy.

当细胞消耗能量来运输离子并建立膜电位时，它们反过来利用这种潜能来运输其他离子和代谢物，如糖。线粒体的膜电位驱动 ATP 的产生，ATP 是生物能量的通用货币。

当细胞消耗能量来转运离子并建立膜电位时，它们反过来利用这种势能来转运其他离子和代谢物，如糖。线粒体的膜电位驱动 ATP 的产生，ATP 是生物能量的通货。

Cells may draw on the energy they store in the resting potential to drive action potentials or other forms of excitation. These changes in the membrane potential enable communication with other cells (as with action potentials) or initiate changes inside the cell, which happens in an [[Ovum|egg]] when it is [[fertilization|fertilized]] by a [[sperm]].

Cells may draw on the energy they store in the resting potential to drive action potentials or other forms of excitation. These changes in the membrane potential enable communication with other cells (as with action potentials) or initiate changes inside the cell, which happens in an [[Ovum|egg]] when it is [[fertilization|fertilized]] by a [[sperm]].

In neuronal cells, an action potential begins with a rush of sodium ions into the cell through sodium channels, resulting in depolarization, while recovery involves an outward rush of potassium through potassium channels. Both of these fluxes occur by [[passive transport|passive diffusion]].

In neuronal cells, an action potential begins with a rush of sodium ions into the cell through sodium channels, resulting in depolarization, while recovery involves an outward rush of potassium through potassium channels. Both of these fluxes occur by [[passive transport|passive diffusion]].

==See also==

==See also==