562:. A simple example wherein two solutionsâA and Bâare separated by a porous barrier illustrates that diffusion will ensure that they will eventually mix into equal solutions. This mixing occurs because of the difference in their concentrations. The region with high concentration will diffuse out toward the region with low concentration. To extend the example, let solution A have 30 sodium ions and 30 chloride ions. Also, let solution B have only 20 sodium ions and 20 chloride ions. Assuming the barrier allows both types of ions to travel through it, then a steady state will be reached whereby both solutions have 25 sodium ions and 25 chloride ions. If, however, the porous barrier is selective to which ions are let through, then diffusion alone will not determine the resulting solution. Returning to the previous example, let's now construct a barrier that is permeable only to sodium ions. Now, only sodium is allowed to diffuse cross the barrier from its higher concentration in solution A to the lower concentration in solution B. This will result in a greater accumulation of sodium ions than chloride ions in solution B and a lesser number of sodium ions than chloride ions in solution A.
511:
606:. Resistance arises from the fact that the membrane impedes the movement of charges across it. Capacitance arises from the fact that the lipid bilayer is so thin that an accumulation of charged particles on one side gives rise to an electrical force that pulls oppositely charged particles toward the other side. The capacitance of the membrane is relatively unaffected by the molecules that are embedded in it, so it has a more or less invariant value estimated at 2 ÎŒF/cm (the total capacitance of a patch of membrane is proportional to its area). The conductance of a pure lipid bilayer is so low, on the other hand, that in biological situations it is always dominated by the conductance of alternative pathways provided by embedded molecules. Thus, the capacitance of the membrane is more or less fixed, but the resistance is highly variable.
779:
737:. This pump operates in a conceptually similar way to the sodium-potassium pump, except that in each cycle it exchanges three Na from the extracellular space for one Ca from the intracellular space. Because the net flow of charge is inward, this pump runs "downhill", in effect, and therefore does not require any energy source except the membrane voltage. Its most important effect is to pump calcium outwardâit also allows an inward flow of sodium, thereby counteracting the sodium-potassium pump, but, because overall sodium and potassium concentrations are much higher than calcium concentrations, this effect is relatively unimportant. The net result of the sodium-calcium exchanger is that in the resting state, intracellular calcium concentrations become very low.
756:
771:
charge and differ only slightly in their radius. The channel pore is typically so small that ions must pass through it in single-file order. Channel pores can be either open or closed for ion passage, although a number of channels demonstrate various sub-conductance levels. When a channel is open, ions permeate through the channel pore down the transmembrane concentration gradient for that particular ion. Rate of ionic flow through the channel, i.e. single-channel current amplitude, is determined by the maximum channel conductance and electrochemical driving force for that ion, which is the difference between the instantaneous value of the membrane potential and the value of the
1912:
cell do not change significantly. They remain close to their respective concentrations when then membrane is at resting potential.) In most animal cells, the permeability to potassium is much higher in the resting state than the permeability to sodium. As a consequence, the resting potential is usually close to the potassium reversal potential. The permeability to chloride can be high enough to be significant, but, unlike the other ions, chloride is not actively pumped, and therefore equilibrates at a reversal potential very close to the resting potential determined by the other ions.
623:
1453:, 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
653:, both usually formed from assemblages of protein molecules. Ion channels provide passageways through which ions can move. In most cases, an ion channel is permeable only to specific types of ions (for example, sodium and potassium but not chloride or calcium), and sometimes the permeability varies depending on the direction of ion movement. Ion pumps, also known as ion transporters or carrier proteins, actively transport specific types of ions from one side of the membrane to the other, sometimes using energy derived from metabolic processes to do so.
1950:
exception of Ca, where the baseline intracellular concentration is so low that even a small influx may increase it by orders of magnitude), but the permeabilities of the ions can change in a fraction of a millisecond, as a result of activation of ligand-gated ion channels. The change in membrane potential can be either large or small, depending on how many ion channels are activated and what type they are, and can be either long or short, depending on the lengths of time that the channels remain open. Changes of this type are referred to as
937:) of an ion is the value of transmembrane voltage at which diffusive and electrical forces counterbalance, so that there is no net ion flow across the membrane. This means that the transmembrane voltage exactly opposes the force of diffusion of the ion, such that the net current of the ion across the membrane is zero and unchanging. The reversal potential is important because it gives the voltage that acts on channels permeable to that ionâin other words, it gives the voltage that the ion concentration gradient generates when it acts as a
566:
ions. Since opposite charges attract and like charges repel, the ions are now also influenced by electrical fields as well as forces of diffusion. Therefore, positive sodium ions will be less likely to travel to the now-more-positive B solution and remain in the now-more-negative A solution. The point at which the forces of the electric fields completely counteract the force due to diffusion is called the equilibrium potential. At this point, the net flow of the specific ion (in this case sodium) is zero.
575:
1442:
662:
133:
1462:
1962:
Likewise, opening K channels shifts the membrane potential toward about â90 mV, and opening Cl channels shifts it toward about â70 mV (resting potential of most membranes). Thus, Na channels shift the membrane potential in a positive direction, K channels shift it in a negative direction (except when the membrane is hyperpolarized to a value more negative than the K reversal potential), and Cl channels tend to shift it towards the resting potential.
1895:
1433:. 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.
1941:
implies that few leakage channels are present at this stage of cell life. As an apparent result, potassium permeability becomes similar to that for sodium ions, which places resting potential in-between the reversal potentials for sodium and potassium as discussed above. The reduced leakage currents also mean there is little need for active pumping in order to compensate, therefore low metabolic cost.
36:
1916:
spontaneous generation of action potentials. Immature or undifferentiated cells show highly variable values of resting voltage, usually significantly more positive than in differentiated cells. In such cells, the resting potential value correlates with the degree of differentiation: undifferentiated cells in some cases may not show any transmembrane voltage difference at all.
1966:
405:
718:
The pump has three effects: (1) it makes the sodium concentration high in the extracellular space and low in the intracellular space; (2) it makes the potassium concentration high in the intracellular space and low in the extracellular space; (3) it gives the intracellular space a negative voltage with respect to the extracellular space.
1534:
905:, are channels whose permeability is influenced by the membrane potential. They form another very large group, with each member having a particular ion selectivity and a particular voltage dependence. Many are also time-dependentâin other words, they do not respond immediately to a voltage change but only after a delay.
421:: V=IR, where V is voltage, I is current and R is resistance. If a voltage source such as a battery is placed in an electrical circuit, the higher the voltage of the source the greater the amount of current that it will drive across the available resistance. The functional significance of voltage lies only in potential
1528:. This is similar in form to the Nernst equation shown above, in that it is based on the charges of the ions in question, as well as the difference between their inside and outside concentrations. However, it also takes into consideration the relative permeability of the plasma membrane to each ion in question.
1911:
In essence, the
Goldman formula expresses the membrane potential as a weighted average of the reversal potentials for the individual ion types, weighted by permeability. (Although the membrane potential changes about 100 mV during an action potential, the concentrations of ions inside and outside the
717:
If the numbers of each type of ion were equal, the sodiumâpotassium pump would be electrically neutral, but, because of the three-for-two exchange, it gives a net movement of one positive charge from intracellular to extracellular for each cycle, thereby contributing to a positive voltage difference.
265:
Almost all plasma membranes have an electrical potential across them, with the inside usually negative with respect to the outside. 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
1508:
or resting voltage. This term is used for the membrane potential of non-excitable cells, but also for the membrane potential of excitable cells in the absence of excitation. In excitable cells, the other possible states are graded membrane potentials (of variable amplitude), and action potentials,
725:
Ion pumps influence the action potential only by establishing the relative ratio of intracellular and extracellular ion concentrations. The action potential involves mainly the opening and closing of ion channels not ion pumps. If the ion pumps are turned off by removing their energy source, or by
483:
Because the electric field is the gradient of the voltage distribution, rapid changes in voltage within a small region imply a strong electric field; on the converse, if the voltage remains approximately the same over a large region, the electric fields in that region must be weak. A strong electric
286:
Signals are generated in excitable cells 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
2250:
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 â70 mV implies that the interior
1949:
As explained above, the potential at any point in a cell's membrane is determined by the ion concentration differences between the intracellular and extracellular areas, and by the permeability of the membrane to each type of ion. The ion concentrations do not normally change very quickly (with the
1940:
On the other hand, the high resting potential in undifferentiated cells does not necessarily incur a high metabolic cost. This apparent paradox is resolved by examination of the origin of that resting potential. Little-differentiated cells are characterized by extremely high input resistance, which
1915:
Values of resting membrane potential in most animal cells usually vary between the potassium reversal potential (usually around -80 mV) and around -40 mV. The resting potential in excitable cells (capable of producing action potentials) is usually near -60 mVâmore depolarized voltages would lead to
1230:
Cell excitability is the change in membrane potential that is necessary for cellular responses in various tissues. Cell excitability is a property that is induced during early embriogenesis. Excitability of a cell has also been defined as the ease with which a response may be triggered. The resting
721:
The sodium-potassium pump is relatively slow in operation. If a cell were initialized with equal concentrations of sodium and potassium everywhere, it would take hours for the pump to establish equilibrium. The pump operates constantly, but becomes progressively less efficient as the concentrations
594:
with many types of large molecules embedded in it. Because it is made of lipid molecules, the plasma membrane intrinsically has a high electrical resistivity, in other words a low intrinsic permeability to ions. However, some of the molecules embedded in the membrane are capable either of actively
389:
The membrane potential in a cell derives ultimately from two factors: electrical force and diffusion. Electrical force arises from the mutual attraction between particles with opposite electrical charges (positive and negative) and the mutual repulsion between particles with the same type of charge
2112:
or the weighted means equation. By plugging in the concentration gradients and the permeabilities of the ions at any instant in time, one can determine the membrane potential at that moment. What the GHK equations means is that, at any time, the value of the membrane potential will be a weighted
2018:
membrane potential is merely the membrane potential that results from the membrane permeabilities that predominate when the cell is resting. The above equation of weighted averages always applies, but the following approach may be more easily visualized. At any given moment, there are two factors
1495:
is the net resistance. For realistic situations, the time constant usually lies in the 1â100 millisecond range. In most cases, changes in the conductance of ion channels occur on a faster time scale, so an RC circuit is not a good approximation; however, the differential equation used to model a
609:
The thickness of a plasma membrane is estimated to be about 7-8 nanometers. Because the membrane is so thin, it does not take a very large transmembrane voltage to create a strong electric field within it. Typical membrane potentials in animal cells are on the order of 100 millivolts (that is, one
1993:
Whether a postsynaptic potential is considered excitatory or inhibitory depends on the reversal potential for the ions of that current, and the threshold for the cell to fire an action potential (around â50mV). A postsynaptic current with a reversal potential above threshold, such as a typical Na
1919:
Maintenance of the resting potential can be metabolically costly for a cell because of its requirement for active pumping of ions to counteract losses due to leakage channels. The cost is highest when the cell function requires an especially depolarized value of membrane voltage. For example, the
770:
with a pore through which ions can travel between extracellular space and cell interior. Most channels are specific (selective) for one ion; for example, most potassium channels are characterized by 1000:1 selectivity ratio for potassium over sodium, though potassium and sodium ions have the same
436:
The same principle applies to voltage in cell biology. In electrically active tissue, the potential difference between any two points can be measured by inserting an electrode at each point, for example one inside and one outside the cell, and connecting both electrodes to the leads of what is in
313:
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
920:
in their Nobel Prize-winning studies of the physiology of the action potential. The channel is closed at the resting voltage level, but opens abruptly when the voltage exceeds a certain threshold, allowing a large influx of sodium ions that produces a very rapid change in the membrane potential.
565:
This means that there is a net positive charge in solution B from the higher concentration of positively charged sodium ions than negatively charged chloride ions. Likewise, there is a net negative charge in solution A from the greater concentration of negative chloride ions than positive sodium
514:
Ions (pink circles) will flow across a membrane from the higher concentration to the lower concentration (down a concentration gradient), causing a current. However, this creates a voltage across the membrane that opposes the ions' motion. When this voltage reaches the equilibrium value, the two
479:
is referred to as the voltage distribution. The definition allows for an arbitrary constant of integrationâthis is why absolute values of voltage are not meaningful. In general, electric fields can be treated as conservative only if magnetic fields do not significantly influence them, but this
425:
between two points in a circuit. The idea of a voltage at a single point is meaningless. It is conventional in electronics to assign a voltage of zero to some arbitrarily chosen element of the circuit, and then assign voltages for other elements measured relative to that zero point. There is no
1900:
The three ions that appear in this equation are potassium (K), sodium (Na), and chloride (Cl). Calcium is omitted, but can be added to deal with situations in which it plays a significant role. Being an anion, the chloride terms are treated differently from the cation terms; the intracellular
843:
368:
In the simplest case, illustrated in the top diagram ("Ion concentration gradients"), if the membrane is selectively permeable to potassium, these positively charged ions can diffuse down the concentration gradient to the outside of the cell, leaving behind uncompensated negative charges. This
294:. For neurons, resting potential is defined as ranging from â80 to â70 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
1961:
shown above, the effect of increasing the permeability of a membrane to a particular type of ion shifts the membrane potential toward the reversal potential for that ion. Thus, opening Na channels shifts the membrane potential toward the Na reversal potential, which is usually around +100 mV.
1172:
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
380:
The top diagram is only an approximation of the ionic contributions to the membrane potential. Other ions including sodium, chloride, calcium, and others play a more minor role, even though they have strong concentration gradients, because they have more limited permeability than potassium.
1994:
current, is considered excitatory. A current with a reversal potential below threshold, such as a typical K current, is considered inhibitory. A current with a reversal potential above the resting potential, but below threshold, will not by itself elicit action potentials, but will produce
2080:
So, in a resting membrane, while the driving force for potassium is low, its permeability is very high. Sodium has a huge driving force but almost no resting permeability. In this case, potassium carries about 20 times more current than sodium, and thus has 20 times more influence over
829:
are the simplest type of ion channel, in that their permeability is more or less constant. The types of leakage channels that have the greatest significance in neurons are potassium and chloride channels. Even these are not perfectly constant in their properties: First, most of them are
790:
of the protein), but each such state is either open or closed. In general, closed states correspond either to a contraction of the poreâmaking it impassable to the ionâor to a separate part of the protein, stoppering the pore. For example, the voltage-dependent sodium channel undergoes
3197:
Spinelli, Valentina; Sartiani, Laura; Mugelli, Alessandro; Romanelli, Maria
Novella; Cerbai, Elisabetta (2018). "Hyperpolarization-activated cyclic-nucleotide-gated channels: pathophysiological, developmental, and pharmacological insights into their function in cellular excitability".
2133:
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
1890:{\displaystyle E_{m}={\frac {RT}{F}}\ln {\left({\frac {P_{\mathrm {K} }_{\mathrm {out} }+P_{\mathrm {Na} }_{\mathrm {out} }+P_{\mathrm {Cl} }_{\mathrm {in} }}{P_{\mathrm {K} }_{\mathrm {in} }+P_{\mathrm {Na} }_{\mathrm {in} }+P_{\mathrm {Cl} }_{\mathrm {out} }}}\right)}}
701:
ions K inside the neuron is roughly 30-fold larger than the outside concentration, whereas the sodium concentration outside is roughly five-fold larger than inside. In a similar manner, other ions have different concentrations inside and outside the neuron, such as
437:
essence a specialized voltmeter. By convention, the zero potential value is assigned to the outside of the cell and the sign of the potential difference between the outside and the inside is determined by the potential of the inside relative to the outside zero.
690:, i.e., use cellular energy (ATP) to "pump" the ions against their concentration gradient. Such ion pumps take in ions from one side of the membrane (decreasing its concentration there) and release them on the other side (increasing its concentration there).
1989:
that act to open Na channels typically cause the membrane potential to become more positive, while neurotransmitters that activate K channels typically cause it to become more negative; those that inhibit these channels tend to have the opposite effect.
1457:
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.
2152:
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
1480:(resistance-capacitance circuit), and its electrical properties are very simple. Starting from any initial state, the current flowing across either the conductance or the capacitance decays with an exponential time course, with a time constant of
1203:
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.
730:, the axon can still fire hundreds of thousands of action potentials before their amplitudes begin to decay significantly. In particular, ion pumps play no significant role in the repolarization of the membrane after an action potential.
408:
Electric field (arrows) and contours of constant voltage created by a pair of oppositely charged objects. The electric field is at right angles to the voltage contours, and the field is strongest where the spacing between contours is the
921:
Recovery from an action potential is partly dependent on a type of voltage-gated potassium channel that is closed at the resting voltage level but opens as a consequence of the large voltage change produced during the action potential.
372:
The system as a whole is electro-neutral. The uncompensated positive charges outside the cell, and the uncompensated negative charges inside the cell, physically line up on the membrane surface and attract each other across the
2037:
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
1517:. Even in other types of cells, however, the membrane voltage can undergo changes in response to environmental or intracellular stimuli. For example, depolarization of the plasma membrane appears to be an important step in
610:
tenth of a volt), but calculations show that this generates an electric field close to the maximum that the membrane can sustainâit has been calculated that a voltage difference much larger than 200 millivolts could cause
1932:
can be as high as -30 mV. This elevated membrane potential allows the cells to respond very rapidly to visual inputs; the cost is that maintenance of the resting potential may consume more than 20% of overall cellular
306:, 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
853:
are channels whose permeability is greatly increased when some type of chemical ligand binds to the protein structure. Animal cells contain hundreds, if not thousands, of types of these. A large subset function as
1082:
2121:
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
2061:
For example, at our earlier calculated resting potential of â73 mV, the driving force on potassium is 7 mV : (â73 mV) â (â80 mV) = 7 mV. The driving force on sodium would be (â73 mV) â (60 mV) = â133
889:
Neurotransmitter receptors are activated by ligands that appear in the extracellular area, but there are other types of ligand-gated channels that are controlled by interactions on the intracellular side.
3618:
Magnuson DS, Morassutti DJ, Staines WA, McBurney MW, Marshall KC (Jan 14, 1995). "In vivo electrophysiological maturation of neurons derived from a multipotent precursor (embryonal carcinoma) cell line".
377:. Thus, the membrane potential is physically located only in the immediate vicinity of the membrane. It is the separation of these charges across the membrane that is the basis of the membrane voltage.
390:(both positive or both negative). Diffusion arises from the statistical tendency of particles to redistribute from regions where they are highly concentrated to regions where the concentration is low.
210:
and denoted as mV, range from â80 mV to â40 mV. For such typical negative membrane potentials, positive work is required to move a positive charge from the interior to the exterior. However,
314:
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.
582:
lipid bilayer common to all living cells. It contains a variety of biological molecules, primarily proteins and lipids, which are involved in a vast array of cellular processes.
2030:
If the driving force is high, then the ion is being "pushed" across the membrane. If the permeability is high, it will be easier for the ion to diffuse across the membrane.
782:
Depiction of the open potassium channel, with the potassium ion shown in purple in the middle, and hydrogen atoms omitted. When the channel is closed, the passage is blocked.
1445:
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
2091:
However, consider another caseâthe peak of the action potential. Here, permeability to Na is high and K permeability is relatively low. Thus, the membrane moves to near
795:, in which a portion of the protein swings into the pore, sealing it. This inactivation shuts off the sodium current and plays a critical role in the action potential.
633:
The resistance of a pure lipid bilayer to the passage of ions across it is very high, but structures embedded in the membrane can greatly enhance ion movement, either
3782:
759:
Despite the small differences in their radii, ions rarely go through the "wrong" channel. For example, sodium or calcium ions rarely pass through a potassium channel.
3869:
3429:"From single cells and single columns to cortical networks: dendritic excitability, coincidence detection and synaptic transmission in brain slices and brains"
1995:
214:
allows ions to overcome the potential difference. For a selectively permeable membrane, this permits a net flow against the gradient. This is a kind of
908:
One of the most important members of this group is a type of voltage-gated sodium channel that underlies action potentialsâthese are sometimes called
302:
if the interior voltage becomes more negative (say from â70 mV to â80 mV). In excitable cells, a sufficiently large depolarization can evoke an
290:
In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the
2006:, or IPSPs. When multiple types of channels are open within the same time period, their postsynaptic potentials summate (are added together).
1476:
as described below, to a circuit containing a capacitance in parallel with a battery and conductance. In electrical terms, this is a type of
258:
allow ions to move across the membrane down those concentration gradients. Ion pumps and ion channels are electrically equivalent to a set of
2917:
2525:
798:
Ion channels can be classified by how they respond to their environment. For example, the ion channels involved in the action potential are
484:
field, equivalent to a strong voltage gradient, implies that a strong force is exerted on any charged particles that lie within the region.
961:
3838:
2149:
Changes in the dielectric properties of plasma membrane may act as hallmark of underlying conditions such as diabetes and dyslipidemia.
53:
3811:
3746:
Ghoshal K, et al. (December 2017). "Dielectric properties of plasma membrane: A signature for dyslipidemia in diabetes mellitus".
834:); second, some of them are capable of being shut off by chemical ligands even though they do not require ligands in order to operate.
430:. However, in most cases and by convention, the zero level is most often assigned to the portion of a circuit that is in contact with
365:
to drive the formation of the membrane potential. This voltage is established when the membrane has permeability to one or more ions.
4082:
4009:
3994:
3980:
3966:
3951:
3936:
3067:
2800:
2284:
2113:
average of the equilibrium potentials of all permeant ions. The "weighting" is the ions relative permeability across the membrane.
2003:
1999:
1901:
concentration is in the numerator, and the extracellular concentration in the denominator, which is reversed from the cation terms.
426:
significance in which element is chosen as the zero pointâthe function of a circuit depends only on the differences not on voltages
119:
2108:
The more ions are permeant the more complicated it becomes to predict the membrane potential. However, this can be done using the
1472:
For fixed ion concentrations and fixed values of ion channel conductance, the equivalent circuit can be further reduced, using the
2068:
is a measure of how easily an ion can cross the membrane. It is normally measured as the (electrical) conductance and the unit,
1981:âa temporary change in membrane potential produced by activation of a synapse by a single graded or action potential is called a
1449:
Electrophysiologists model the effects of ionic concentration differences, ion channels, and membrane capacitance in terms of an
100:
72:
4026:
1509:
which are large, all-or-nothing rises in membrane potential that usually follow a fixed time course. Excitable cells include
1180:
is â84 mV with 5 mM potassium outside and 140 mM inside. On the other hand, the sodium equilibrium potential,
4077:
1235:
forms the basis of cell excitability and these processes are fundamental for the generation of graded and action potentials.
57:
2271:
Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Morgan, David; Raff, Martin; Roberts, Keith; Walter, Peter (2014-11-18).
1504:
When the membrane potential of a cell goes for a long period of time without changing significantly, it is referred to as a
417:, is the ability to drive an electric current across a resistance. Indeed, the simplest definition of a voltage is given by
1331:
622:
79:
4041:
2813:
Eisenman G (1961). "On the elementary atomic origin of equilibrium ionic specificity". In A Kleinzeller; A Kotyk (eds.).
449:, a vector field assigning a magnitude and direction to each point in space. In many situations, the electric field is a
1929:
697:, which transports three sodium ions out of the cell and two potassium ions in. As a consequence, the concentration of
2461:
Mummert H, Gradmann D (1991). "Action potentials in
Acetabularia: measurement and simulation of voltage-gated fluxes".
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86:
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transporting ions from one side of the membrane to the other or of providing channels through which they can move.
1271:
830:
voltage-dependent in the sense that they conduct better in one direction than the other (in other words, they are
46:
4092:
2276:
2183:
1255:
898:
855:
767:
683:
665:
The sodium-potassium pump uses energy derived from ATP to exchange sodium for potassium ions across the membrane.
307:
161:
structure with an arrow represents a transmembrane potassium channel and the direction of net potassium movement.
2829:
Diamond JM, Wright EM (1969). "Biological membranes: the physical basis of ion and nonekectrolyte selectivity".
2618:"The effects of injecting energy-rich phosphate compounds on the active transport of ions in the giant axons of
254:
proteins, actively push ions across the membrane and establish concentration gradients across the membrane, and
1287:
850:
734:
505:
501:
68:
3703:
Laughlin SB, de Ruyter van
Steveninck RR, Anderson JC (May 1998). "The metabolic cost of neural information".
2213:
262:
and resistors inserted in the membrane, and therefore create a voltage between the two sides of the membrane.
3550:
Spangler SG (1972). "Expansion of the constant field equation to include both divalent and monovalent ions".
4067:
4031:
3602:
3581:
3537:
2937:
2448:
2436:
1303:
1275:
2950:
Sanes, Dan H.; TakĂĄcs, Catherine (1993-06-01). "Activity-dependent
Refinement of Inhibitory Connections".
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1982:
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243:
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807:
646:
642:
259:
2019:
for an ion that determine how much influence that ion will have over the membrane potential of a cell:
814:. Other ion channels open and close with mechanical forces. Still other ion channelsâsuch as those of
574:
188:) per charge which is required to move a (very small) positive charge at constant velocity across the
155:
rectangles â membrane-impermeable anions (these arise from a variety of sources including proteins).
3585:
3368:
Davenport, Bennett; Li, Yuan; Heizer, Justin W.; Schmitz, Carsten; Perraud, Anne-Laure (2015-07-23).
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embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of
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may trigger the still-working neurons of a fresh cut of meat into firing, causing muscle spasms.
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913:
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form another important class; these ion channels open and close in response to the binding of a
93:
3846:
3488:"Potential roles of electrogenic ion transport and plasma membrane depolarization in apoptosis"
2725:
Steinbach HB, Spiegelman S (1943). "The sodium and potassium balance in squid nerve axoplasm".
1212:. The addition of these glial cells increases the organism's ability to regulate extracellular
192:
from the exterior to the interior. (If the charge is allowed to change velocity, the change of
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2154:
1505:
1135:
787:
750:
638:
291:
3656:"Contrast gain, signal-to-noise ratio, and linearity in light-adapted blowfly photoreceptors"
3150:"Analysis of the effects of changes in rate and rhythm upon electrical activity in the heart"
1216:. The drop in extracellular potassium can lead to a decrease in membrane potential of 35 mV.
3755:
3712:
3675:
3667:
3628:
3499:
3458:
3440:
3399:
3381:
3334:
3290:
3272:
3215:
3207:
3161:
3104:
3030:
3014:
2959:
2940:, Orkand, and Grinnell, pp. 133â134; Schmidt-Nielsen, pp. 478â480, 596â597; Junge, pp. 33â35
2882:
2838:
2767:
2734:
2697:
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2641:
2633:
2580:
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2383:
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1986:
1958:
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1225:
1145:
811:
755:
687:
674:
634:
627:
362:
345:(K), which is at a high concentration inside and a low concentration outside the membrane.
303:
1337:
Many cell types are considered to have an excitable membrane. Excitable cells are neurons,
2678:
2161:
2002:, or EPSPs, whereas neurotransmitters that act to open K or Cl channels typically produce
1402:
1346:
1311:
1263:
1259:
1187:, is approximately +66 mV with approximately 12 mM sodium inside and 140 mM outside.
952:
826:
694:
679:
670:
650:
587:
327:
251:
247:
184:. It equals the interior potential minus the exterior potential. This is the energy (i.e.
874:
that when activated allows passage of sodium and potassium ions. Another example is the
4046:
4021:
2842:
2387:
3680:
3655:
3463:
3428:
3404:
3369:
3295:
3261:"Calcium-Sensing Receptor: A Key Target for Extracellular Calcium Signaling in Neurons"
3260:
3035:
3018:
3002:
2963:
2873:
Cai SQ, Li W, Sesti F (2007). "Multiple modes of a-type potassium current regulation".
2771:
2702:
2673:
2646:
2617:
2613:
2585:
2552:
2548:
2344:
2309:
2069:
1422:
1342:
1307:
875:
815:
559:
441:
295:
211:
197:
193:
185:
181:
17:
818:âopen and close in response to other stimuli, such as light, temperature or pressure.
4056:
3732:
3632:
3166:
3149:
2516:
Lieb WR, Stein WD (1986). "Chapter 2. Simple
Diffusion across the Membrane Barrier".
2139:
1921:
1414:
1350:
1319:
917:
871:
867:
863:
591:
374:
358:
354:
231:
227:
189:
3354:
3245:
3134:
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2490:
944:
The equilibrium potential of a particular ion is usually designated by the notation
287:
can then open or close as a result of the potential change, reproducing the signal.
3816:
2637:
2576:
1323:
1107:
859:
3519:
2820:
Eisenman G (1965). "Some elementary factors involved in specific ion permeation".
1954:, in contrast to action potentials, which have a fixed amplitude and time course.
1254:) and associated proteins. Important proteins that regulate cell excitability are
778:
418:
535:
cations that carry a single positive charge. Action potentials can also involve
3812:"Watch: Slab of Raw Beef Appears to Pulse After Being Brought Home From Butcher"
1426:
1418:
1410:
1394:
1354:
1338:
1279:
1243:
1239:
1159:
763:
746:
298:
if the interior voltage becomes less negative (say from â70 mV to â60 mV), or a
255:
35:
27:
Electric potential difference between interior and exterior of a biological cell
4004:. Lippincott Williams & Wilkins. Philadelphia, PA, USA 4th Edition, 2001.
3540:, Orkand, and Grinnell, pp. 138â140; Schmidt-Nielsen, pp. 480; Junge, pp. 35â37
3338:
2886:
440:
In mathematical terms, the definition of voltage begins with the concept of an
3902:
3759:
3503:
2692:
2368:
2310:"Emerging Roles of the Membrane Potential: Action Beyond the Action Potential"
1477:
1382:
1378:
1370:
1299:
862:
sites, and the chemical ligand that gates them is released by the presynaptic
649:. The two types of structure that play the largest roles are ion channels and
404:
3454:
3395:
3386:
3370:"Signature Channels of Excitability no More: L-Type Channels in Immune Cells"
3286:
3277:
3229:
3175:
3118:
3077:
3026:
2971:
2335:
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1518:
1406:
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1213:
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are also differentiating and proliferating as development progresses in the
1205:
831:
711:
698:
603:
555:
528:
497:
342:
3987:
Biological
Membranes: Theory of Transport, Potentials and Electric Impulses
3767:
3724:
3511:
3472:
3413:
3346:
3304:
3237:
3211:
3126:
3044:
2894:
2738:
2711:
2655:
2594:
2353:
1969:
Graph displaying an EPSP, an IPSP, and the summation of an EPSP and an IPSP
1965:
3689:
3671:
3640:
3563:
3183:
2979:
2850:
2482:
1496:
membrane patch is commonly a modified version of the RC circuit equation.
1465:
Reduced circuit obtained by combining the ion-specific pathways using the
519:
Electrical signals within biological organisms are, in general, driven by
510:
3870:"Common condiment causes freshly cut meat to pulsate, horrifying Twitter"
2908:
Goldin AL (2007). "Neuronal
Channels and Receptors". In Waxman SG (ed.).
2395:
1358:
1327:
955:. For example, reversal potential for potassium ions will be as follows:
707:
599:
544:
454:
350:
278:, it is used for transmitting signals between different parts of a cell.
1524:
The interactions that generate the resting potential are modeled by the
786:
A channel may have several different states (corresponding to different
578:
The cell membrane, also called the plasma membrane or plasmalemma, is a
551:, but plays a negligible role in the action potentials of most animals.
341:
Many ions have a concentration gradient across the membrane, including
3874:
2474:
2073:
1978:
1291:
1149:
727:
703:
598:
In electrical terminology, the plasma membrane functions as a combined
536:
399:
331:
275:
235:
215:
3220:
3109:
3092:
2758:(1951). "The ionic basis of electrical activity in nerve and muscle".
802:; they open and close in response to the voltage across the membrane.
3898:"Beef twerky: internet horrified over video of fresh meat 'spasming'"
3445:
1974:
1510:
1196:
1125:
1077:{\displaystyle E_{eq,K^{+}}={\frac {RT}{zF}}\ln {\frac {_{o}}{_{i}}}}
524:
346:
271:
3487:
2308:
Abdul Kadir, Lina; Stacey, Michael; Barrett-Jolley, Richard (2018).
951:.The equilibrium potential for any ion can be calculated using the
2143:
1964:
1514:
1460:
1440:
1209:
1111:
841:
777:
754:
660:
626:
Facilitated diffusion in cell membranes, showing ion channels and
621:
573:
548:
509:
403:
204:
3975:
Sinauer
Associates, Inc. Sunderland, MA, USA 3rd Edition, 1992.
2674:"Sodium Transporters in Human Health and Disease (Figure 2)"
1322:
and other hormones also regulate cell excitability, for example,
203:
Typical values of membrane potential, normally given in units of
3716:
3654:
Juusola M, Kouvalainen E, JÀrvilehto M, Weckström M (Sep 1994).
2135:
1398:
1098:
883:
207:
3318:
Debanne, Dominique; Inglebert, Yanis; Russier, Michaël (2019).
1998:. Thus, neurotransmitters that act to open Na channels produce
842:
547:
anion (Cl) plays a major role in the action potentials of some
520:
493:
323:
239:
29:
3961:
Sinauer
Associates, Sunderland, MA, USA; 1st Edition, 1984.
3062:(Third ed.). Elsevier Academic Press. pp. 211â214.
369:
separation of charges is what causes the membrane potential.
3931:. Garland Publishing; 4th Bk&Cdr edition (March, 2002).
1280:
hyperpolarization-activated cyclic-nucleotide-gated channels
3613:
3611:
2912:. Burlington, MA: Elsevier Academic Press. pp. 43â58.
722:
of sodium and potassium available for pumping are reduced.
523:. The most important cations for the action potential are
1199:'s resting membrane potential actually changes during the
693:
The ion pump most relevant to the action potential is the
3946:. W.B. Saunders Company; 10th edition (August 15, 2000).
1973:
Graded membrane potentials are particularly important in
1908:
stands for the relative permeability of the ion type i.
1158:= extracellular concentration of potassium, measured in
2045:). So, in formal terms, the driving force for an ion =
846:
Ligand-gated calcium channel in closed and open states
180:
between the interior and the exterior of a biological
2130:, which is the common currency of biological energy.
1537:
964:
886:
that when activated allows passage of chloride ions.
480:
condition usually applies well to biological tissue.
3093:"Dynamic roles of ion currents in early development"
3989:. Cambridge University Press (September 26, 2002).
3486:Franco R, Bortner CD, Cidlowski JA (January 2006).
3003:"Potassium buffering in the central nervous system"
1097:= equilibrium potential for potassium, measured in
554:Ions cross the cell membrane under two influences:
543:cation that carries a double positive charge. The
361:regions. These concentration gradients provide the
60:. Unsourced material may be challenged and removed.
2824:. Amsterdam: Excerta Med. Found. pp. 489â506.
1889:
1076:
3259:Jones, Brian L.; Smith, Stephen M. (2016-03-30).
2553:"Active transport of cations in giant axons from
2432:
2430:
2251:of the cell is negative relative to the exterior.
3971:Nicholls, J.G., Martin, A.R. and Wallace, B.G.
1191:Changes to membrane potential during development
4000:National Medical Series for Independent Study.
3320:"Plasticity of intrinsic neuronal excitability"
3200:Canadian Journal of Physiology and Pharmacology
2750:
2748:
2667:
2665:
2539:
2537:
1138:of the ion in question involved in the reaction
733:Another functionally important ion pump is the
2815:Symposium on Membrane Transport and Metabolism
2520:. San Diego: Academic Press. pp. 69â112.
2376:Annual Review of Biophysics and Bioengineering
2367:Jaffe, Lionel F.; Nuccitelli, Richard (1977).
1488:is the capacitance of the membrane patch, and
453:, which means that it can be expressed as the
2518:Transport and Diffusion across Cell Membranes
1310:. Activation of synaptic receptors initiates
912:because they were initially characterized by
8:
4047:The Origin of the Resting Membrane Potential
3154:Progress in Biophysics and Molecular Biology
2817:. New York: Academic Press. pp. 163â79.
1996:subthreshold membrane potential oscillations
1513:, muscle cells, and some secretory cells in
1290:are important regulators of excitability in
353:(Cl) ions are at high concentrations in the
3058:Sanes, Dan H.; Reh, Thomas A (2012-01-01).
2822:Proc. 23rd Int. Congr. Physiol. Sci., Tokyo
1242:of cell excitability are the extracellular
1168:= intracellular concentration of potassium
3679:
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3444:
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3385:
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1701:
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1666:
1665:
1655:
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1633:
1632:
1612:
1611:
1601:
1596:
1585:
1584:
1577:
1572:
1551:
1542:
1536:
1302:. Calcium ion is also the most important
1065:
1055:
1040:
1030:
1020:
994:
983:
969:
963:
120:Learn how and when to remove this message
4042:Electrochemical Driving Force Calculator
4037:Goldman-Hodgkin-Katz Equation Calculator
3001:KOFUJI, P.; NEWMAN, E. A. (2004-01-01).
488:Ions and the forces driving their motion
131:
2263:
2229:
1454:
614:, that is, arcing across the membrane.
3097:Molecular Reproduction and Development
2072:, corresponds to 1 C·s·V, that is one
2014:From the viewpoint of biophysics, the
1920:resting potential in daylight-adapted
882:, a receptor for the neurotransmitter
870:, a receptor for the neurotransmitter
357:region, and low concentrations in the
266:the membrane. Second, in electrically
4049:- Online interactive tutorial (Flash)
2793:CRC Handbook of Chemistry and Physics
322:Differences in the concentrations of
226:All animal cells are surrounded by a
7:
3959:Ionic Channel of Excitable Membranes
2369:"Electrical Controls of Development"
1298:and many other excitable cells like
58:adding citations to reliable sources
3552:Alabama Journal of Medical Sciences
2843:10.1146/annurev.ph.31.030169.003053
2451:, Orkand, and Grinnell, pp. 153â54.
2439:, Orkand, and Grinnell, pp. 140â41.
2388:10.1146/annurev.bb.06.060177.002305
618:Facilitated diffusion and transport
515:balance and the flow of ions stops.
282:Signals in neurons and muscle cells
3781:Wilcox, Christie (July 28, 2011).
3148:Boyet, M.R.; Jewell, B.R. (1981).
3019:10.1016/j.neuroscience.2004.06.008
2964:10.1111/j.1460-9568.1993.tb00522.x
2772:10.1111/j.1469-185X.1951.tb01204.x
2004:inhibitory postsynaptic potentials
2000:excitatory postsynaptic potentials
1873:
1870:
1867:
1851:
1848:
1837:
1834:
1819:
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1800:
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1670:
1667:
1651:
1648:
1637:
1634:
1619:
1616:
1613:
1597:
1586:
866:. One example of this type is the
415:difference in electrical potential
413:Voltage, which is synonymous with
25:
4027:Nernst/Goldman Equation Simulator
3942:Guyton, Arthur C., John E. Hall.
3868:Gibson, Gray (January 11, 2023).
3060:Development of the nervous system
2076:per second per volt of potential.
3783:"Instant Zombie - Just Add Salt"
3584:, Orkand, and Grinnell, p. 134;
3091:Tosti, Elisabetta (2010-06-28).
2952:European Journal of Neuroscience
2275:(Sixth ed.). New York, NY:
1128:(= K = degrees Celsius + 273.15)
34:
3605:, Orkand, and Grinnell, p. 131.
3327:Current Opinion in Neurobiology
590:, which has the structure of a
45:needs additional citations for
4022:Functions of the Cell Membrane
3944:Textbook of medical physiology
2638:10.1113/jphysiol.1960.sp006509
2577:10.1113/jphysiol.1955.sp005290
1862:
1843:
1811:
1792:
1760:
1744:
1716:
1697:
1662:
1643:
1608:
1592:
1391:pulmonary neuroendocrine cells
1062:
1048:
1037:
1023:
910:Hodgkin-Huxley sodium channels
903:voltage dependent ion channels
1:
3929:Molecular Biology of the Cell
3896:Cost, Ben (10 January 2023).
2672:Gagnon KB, Delpire E (2021).
2415:Campbell Biology, 6th edition
2273:Molecular Biology of the Cell
2110:Goldman-Hodgkin-Katz equation
1977:, where they are produced by
1332:myometrial smooth muscle cell
200:must be taken into account.)
3633:10.1016/0165-3806(94)00166-W
3621:Developmental Brain Research
3427:Sakmann, Bert (2017-04-21).
3167:10.1016/0079-6107(81)90003-1
1246:concentrations (i.e. Na, K,
726:adding an inhibitor such as
586:Every cell is enclosed in a
2831:Annual Review of Physiology
2463:Journal of Membrane Biology
1957:As can be derived from the
1367:interstitial cells of Cajal
318:Ion concentration gradients
4109:
4032:Nernst Equation Calculator
3339:10.1016/j.conb.2018.09.001
2887:10.2174/138161207782341286
2277:W. W. Norton & Company
1314:in neuronal excitability.
1256:voltage-gated ion channels
1223:
899:Voltage-gated ion channels
894:Voltage-dependent channels
856:neurotransmitter receptors
800:voltage-sensitive channels
768:integral membrane proteins
744:
684:integral membrane proteins
668:
491:
397:
308:voltage-gated ion channels
147:squares â potassium ions;
3810:Crew, Bec (3 July 2015).
3760:10.1016/j.abb.2017.10.002
3504:10.1007/s00232-005-0837-5
2693:10.3389/fphys.2020.588664
2184:Electrochemical potential
2126:drives the production of
1401:cells (e.g. astrocytes),
1288:calcium-sensing receptors
851:Ligand-gated ion channels
151:circles â chloride ions;
143:pentagons â sodium ions;
4083:Electrochemical concepts
3387:10.3389/fimmu.2015.00375
3278:10.3389/fphys.2016.00116
2327:10.3389/fphys.2018.01661
2117:Effects and implications
2023:That ion's driving force
735:sodium-calcium exchanger
641:, via mechanisms called
506:Electrophoretic mobility
502:Electrochemical gradient
3433:Experimental Physiology
3374:Frontiers in Immunology
3265:Frontiers in Physiology
2679:Frontiers in Physiology
2314:Frontiers in Physiology
2026:That ion's permeability
531:(K). Both of these are
326:on opposite sides of a
176:) is the difference in
170:transmembrane potential
18:Transmembrane potential
3954:. Undergraduate level.
3939:. Undergraduate level.
3212:10.1139/cjpp-2018-0115
2739:10.1002/jcp.1030220209
2727:J. Cell. Comp. Physiol
2424:Johnston and Wu, p. 9.
2179:Chemiosmotic potential
1983:postsynaptic potential
1970:
1891:
1469:
1446:
1272:acidâbase transporters
1268:magnesium transporters
1078:
847:
783:
760:
666:
630:
583:
516:
410:
244:Transmembrane proteins
212:thermal kinetic energy
162:
4078:Cellular neuroscience
3672:10.1085/jgp.104.3.593
2803:, pp. 12â14 to 12â16.
1968:
1892:
1519:programmed cell death
1464:
1444:
1387:enteroendocrine cells
1363:juxtaglomerular cells
1224:Further information:
1079:
935:equilibrium potential
845:
838:Ligand-gated channels
804:Ligand-gated channels
781:
758:
695:sodiumâpotassium pump
664:
647:facilitated diffusion
643:facilitated transport
625:
577:
513:
473:. This scalar field
457:of a scalar function
407:
135:
3973:From Neuron to Brain
3748:Arch Biochem Biophys
2204:Saltatory conduction
2199:Microelectrode array
1535:
1312:long-lasting changes
1233:threshold potentials
1122:absolute temperature
962:
612:dielectric breakdown
69:"Membrane potential"
54:improve this article
3843:legal.people.com.cn
3788:Scientific American
2910:Molecular Neurology
2214:GibbsâDonnan effect
2194:Membrane biophysics
2174:Bioelectrochemistry
1238:The most important
4073:Cellular processes
4063:Cell communication
3985:Ove-Sten Knudsen.
2616:, Shaw TI (1960).
2475:10.1007/BF01994359
2219:Synaptic potential
2088:than does sodium.
1971:
1887:
1470:
1455:Reversal potential
1451:equivalent circuit
1447:
1437:Equivalent circuit
1284:potassium channels
1276:membrane receptors
1148:, equal to 96,485
1136:elementary charges
1074:
931:reversal potential
925:Reversal potential
914:Alan Lloyd Hodgkin
848:
784:
773:reversal potential
761:
667:
631:
584:
517:
451:conservative field
411:
336:membrane potential
196:and production of
178:electric potential
166:Membrane potential
163:
4088:Electrophysiology
3997:. Graduate level.
3110:10.1002/mrd.21215
2919:978-0-12-369509-3
2863:Junge, pp. 33â37.
2527:978-0-12-664661-0
2209:Surface potential
2155:passive diffusion
1987:Neurotransmitters
1952:graded potentials
1945:Graded potentials
1926:Calliphora vicina
1880:
1564:
1506:resting potential
1500:Resting potential
1355:endothelial cells
1220:Cell excitability
1110:, equal to 8.314
1072:
1012:
751:Passive transport
539:(Ca), which is a
328:cellular membrane
300:hyperpolarization
292:resting potential
130:
129:
122:
104:
16:(Redirected from
4100:
4093:Membrane biology
3915:
3914:
3912:
3910:
3893:
3887:
3886:
3884:
3882:
3865:
3859:
3858:
3856:
3854:
3845:. Archived from
3835:
3829:
3828:
3826:
3824:
3807:
3801:
3800:
3798:
3796:
3778:
3772:
3771:
3743:
3737:
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3700:
3694:
3693:
3683:
3651:
3645:
3644:
3615:
3606:
3595:
3589:
3574:
3568:
3567:
3547:
3541:
3530:
3524:
3523:
3483:
3477:
3476:
3466:
3448:
3446:10.1113/ep085776
3424:
3418:
3417:
3407:
3389:
3365:
3359:
3358:
3324:
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3309:
3308:
3298:
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3249:
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3169:
3145:
3139:
3138:
3112:
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3082:
3081:
3055:
3049:
3048:
3038:
3013:(4): 1045â1056.
2998:
2992:
2991:
2947:
2941:
2930:
2924:
2923:
2905:
2899:
2898:
2875:Curr. Pharm. Des
2870:
2864:
2861:
2855:
2854:
2825:
2818:
2810:
2804:
2795:, 83rd edition,
2790:
2784:
2783:
2752:
2743:
2742:
2722:
2716:
2715:
2705:
2695:
2669:
2660:
2659:
2649:
2605:
2599:
2598:
2588:
2541:
2532:
2531:
2513:
2507:
2501:
2495:
2494:
2458:
2452:
2446:
2440:
2434:
2425:
2422:
2416:
2413:
2407:
2406:
2404:
2402:
2373:
2364:
2358:
2357:
2347:
2329:
2305:
2299:
2298:
2268:
2252:
2234:
2189:Goldman equation
1959:Goldman equation
1896:
1894:
1893:
1888:
1886:
1885:
1881:
1879:
1878:
1877:
1876:
1860:
1859:
1854:
1842:
1841:
1840:
1824:
1823:
1822:
1809:
1808:
1803:
1791:
1790:
1789:
1773:
1772:
1771:
1758:
1757:
1752:
1743:
1742:
1741:
1730:
1729:
1728:
1727:
1714:
1713:
1708:
1696:
1695:
1694:
1678:
1677:
1676:
1660:
1659:
1654:
1642:
1641:
1640:
1624:
1623:
1622:
1606:
1605:
1600:
1591:
1590:
1589:
1578:
1565:
1560:
1552:
1547:
1546:
1526:Goldman equation
1494:
1487:
1483:
1474:Goldman equation
1467:Goldman equation
1371:epithelial cells
1369:, many types of
1304:second messenger
1296:cardiac myocytes
1260:ion transporters
1226:Excitable medium
1146:Faraday constant
1083:
1081:
1080:
1075:
1073:
1071:
1070:
1069:
1060:
1059:
1046:
1045:
1044:
1035:
1034:
1021:
1013:
1011:
1003:
995:
990:
989:
988:
987:
901:, also known as
827:Leakage channels
822:Leakage channels
812:neurotransmitter
688:active transport
675:Active transport
628:carrier proteins
570:Plasma membranes
478:
472:
462:
448:
363:potential energy
304:action potential
246:, also known as
174:membrane voltage
160:
154:
150:
146:
142:
125:
118:
114:
111:
105:
103:
62:
38:
30:
21:
4108:
4107:
4103:
4102:
4101:
4099:
4098:
4097:
4053:
4052:
4018:
3927:Alberts et al.
3924:
3922:Further reading
3919:
3918:
3908:
3906:
3895:
3894:
3890:
3880:
3878:
3867:
3866:
3862:
3852:
3850:
3837:
3836:
3832:
3822:
3820:
3809:
3808:
3804:
3794:
3792:
3780:
3779:
3775:
3745:
3744:
3740:
3702:
3701:
3697:
3653:
3652:
3648:
3617:
3616:
3609:
3596:
3592:
3586:Schmidt-Nielsen
3575:
3571:
3549:
3548:
3544:
3531:
3527:
3485:
3484:
3480:
3426:
3425:
3421:
3367:
3366:
3362:
3322:
3317:
3316:
3312:
3258:
3257:
3253:
3206:(10): 977â984.
3196:
3195:
3191:
3147:
3146:
3142:
3103:(10): 856â867.
3090:
3089:
3085:
3070:
3057:
3056:
3052:
3000:
2999:
2995:
2949:
2948:
2944:
2931:
2927:
2920:
2907:
2906:
2902:
2881:(31): 3178â84.
2872:
2871:
2867:
2862:
2858:
2828:
2826:
2819:
2812:
2811:
2807:
2791:
2787:
2754:
2753:
2746:
2724:
2723:
2719:
2671:
2670:
2663:
2607:
2606:
2602:
2543:
2542:
2535:
2528:
2515:
2514:
2510:
2504:Schmidt-Nielsen
2502:
2498:
2460:
2459:
2455:
2447:
2443:
2435:
2428:
2423:
2419:
2414:
2410:
2400:
2398:
2371:
2366:
2365:
2361:
2307:
2306:
2302:
2287:
2270:
2269:
2265:
2260:
2255:
2249:
2242:
2235:
2231:
2227:
2170:
2119:
2104:
2097:
2087:
2058:
2051:
2044:
2012:
1947:
1907:
1861:
1846:
1828:
1810:
1795:
1777:
1759:
1747:
1732:
1731:
1715:
1700:
1682:
1661:
1646:
1628:
1607:
1595:
1580:
1579:
1573:
1553:
1538:
1533:
1532:
1502:
1493:
1489:
1485:
1481:
1439:
1423:taste receptors
1403:mechanoreceptor
1282:. For example,
1228:
1222:
1193:
1186:
1179:
1167:
1157:
1152:·mol or J·V·mol
1096:
1061:
1051:
1047:
1036:
1026:
1022:
1004:
996:
979:
965:
960:
959:
953:Nernst equation
950:
927:
896:
879:
858:âthey occur at
840:
824:
816:sensory neurons
808:ligand molecule
753:
745:Main articles:
743:
686:that carry out
677:
671:Ion transporter
669:Main articles:
659:
620:
588:plasma membrane
572:
560:electric fields
508:
492:Main articles:
490:
477:
474:
471:
464:
461:
458:
444:
402:
396:
387:
320:
284:
268:excitable cells
248:ion transporter
224:
158:
156:
152:
148:
144:
140:
126:
115:
109:
106:
63:
61:
51:
39:
28:
23:
22:
15:
12:
11:
5:
4106:
4104:
4096:
4095:
4090:
4085:
4080:
4075:
4070:
4068:Cell signaling
4065:
4055:
4054:
4051:
4050:
4044:
4039:
4034:
4029:
4024:
4017:
4016:External links
4014:
4013:
4012:
3998:
3983:
3969:
3955:
3940:
3923:
3920:
3917:
3916:
3888:
3860:
3849:on 3 July 2015
3830:
3802:
3773:
3738:
3695:
3666:(3): 593â621.
3646:
3607:
3590:
3588:, pp. 478â480.
3569:
3542:
3525:
3492:J. Membr. Biol
3478:
3439:(5): 489â521.
3419:
3360:
3310:
3251:
3189:
3140:
3083:
3068:
3050:
2993:
2958:(6): 570â574.
2942:
2925:
2918:
2900:
2865:
2856:
2805:
2785:
2766:(4): 339â409.
2744:
2717:
2661:
2600:
2533:
2526:
2508:
2496:
2453:
2441:
2426:
2417:
2408:
2382:(1): 445â476.
2359:
2300:
2285:
2262:
2261:
2259:
2256:
2254:
2253:
2247:
2240:
2228:
2226:
2223:
2222:
2221:
2216:
2211:
2206:
2201:
2196:
2191:
2186:
2181:
2176:
2169:
2166:
2118:
2115:
2102:
2095:
2085:
2078:
2077:
2063:
2059:
2056:
2049:
2042:
2028:
2027:
2024:
2011:
2008:
1946:
1943:
1930:photoreceptors
1905:
1898:
1897:
1884:
1875:
1872:
1869:
1864:
1858:
1853:
1850:
1845:
1839:
1836:
1831:
1827:
1821:
1818:
1813:
1807:
1802:
1799:
1794:
1788:
1785:
1780:
1776:
1770:
1767:
1762:
1756:
1751:
1746:
1740:
1735:
1726:
1723:
1718:
1712:
1707:
1704:
1699:
1693:
1690:
1685:
1681:
1675:
1672:
1669:
1664:
1658:
1653:
1650:
1645:
1639:
1636:
1631:
1627:
1621:
1618:
1615:
1610:
1604:
1599:
1594:
1588:
1583:
1576:
1571:
1568:
1563:
1559:
1556:
1550:
1545:
1541:
1501:
1498:
1491:
1438:
1435:
1334:excitability.
1308:cell signaling
1221:
1218:
1192:
1189:
1184:
1177:
1170:
1169:
1165:
1163:
1155:
1153:
1139:
1129:
1124:, measured in
1115:
1101:
1094:
1085:
1084:
1068:
1064:
1058:
1054:
1050:
1043:
1039:
1033:
1029:
1025:
1019:
1016:
1010:
1007:
1002:
999:
993:
986:
982:
978:
975:
972:
968:
948:
926:
923:
895:
892:
877:
839:
836:
823:
820:
742:
739:
658:
655:
619:
616:
571:
568:
489:
486:
475:
469:
459:
442:electric field
398:Main article:
395:
392:
386:
385:Physical basis
383:
319:
316:
296:depolarization
283:
280:
230:composed of a
223:
220:
194:kinetic energy
128:
127:
42:
40:
33:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
4105:
4094:
4091:
4089:
4086:
4084:
4081:
4079:
4076:
4074:
4071:
4069:
4066:
4064:
4061:
4060:
4058:
4048:
4045:
4043:
4040:
4038:
4035:
4033:
4030:
4028:
4025:
4023:
4020:
4019:
4015:
4011:
4010:0-683-30603-0
4007:
4003:
3999:
3996:
3995:0-521-81018-3
3992:
3988:
3984:
3982:
3981:0-87893-580-0
3978:
3974:
3970:
3968:
3967:0-87893-322-0
3964:
3960:
3956:
3953:
3952:0-7216-8677-X
3949:
3945:
3941:
3938:
3937:0-8153-3218-1
3934:
3930:
3926:
3925:
3921:
3905:
3904:
3899:
3892:
3889:
3877:
3876:
3871:
3864:
3861:
3848:
3844:
3840:
3834:
3831:
3819:
3818:
3813:
3806:
3803:
3791:
3789:
3784:
3777:
3774:
3769:
3765:
3761:
3757:
3753:
3749:
3742:
3739:
3734:
3730:
3726:
3722:
3718:
3714:
3710:
3706:
3705:Nat. Neurosci
3699:
3696:
3691:
3687:
3682:
3677:
3673:
3669:
3665:
3661:
3660:J Gen Physiol
3657:
3650:
3647:
3642:
3638:
3634:
3630:
3627:(1): 130â41.
3626:
3622:
3614:
3612:
3608:
3604:
3601:, pp. 33â36;
3600:
3594:
3591:
3587:
3583:
3579:
3573:
3570:
3565:
3561:
3558:(2): 218â23.
3557:
3553:
3546:
3543:
3539:
3536:, pp. 32â33;
3535:
3529:
3526:
3521:
3517:
3513:
3509:
3505:
3501:
3497:
3493:
3489:
3482:
3479:
3474:
3470:
3465:
3460:
3456:
3452:
3447:
3442:
3438:
3434:
3430:
3423:
3420:
3415:
3411:
3406:
3401:
3397:
3393:
3388:
3383:
3379:
3375:
3371:
3364:
3361:
3356:
3352:
3348:
3344:
3340:
3336:
3332:
3328:
3321:
3314:
3311:
3306:
3302:
3297:
3292:
3288:
3284:
3279:
3274:
3270:
3266:
3262:
3255:
3252:
3247:
3243:
3239:
3235:
3231:
3227:
3222:
3217:
3213:
3209:
3205:
3201:
3193:
3190:
3185:
3181:
3177:
3173:
3168:
3163:
3159:
3155:
3151:
3144:
3141:
3136:
3132:
3128:
3124:
3120:
3116:
3111:
3106:
3102:
3098:
3094:
3087:
3084:
3079:
3075:
3071:
3069:9780080923208
3065:
3061:
3054:
3051:
3046:
3042:
3037:
3032:
3028:
3024:
3020:
3016:
3012:
3008:
3004:
2997:
2994:
2989:
2985:
2981:
2977:
2973:
2969:
2965:
2961:
2957:
2953:
2946:
2943:
2939:
2936:, pp. 28â32;
2935:
2929:
2926:
2921:
2915:
2911:
2904:
2901:
2896:
2892:
2888:
2884:
2880:
2876:
2869:
2866:
2860:
2857:
2852:
2848:
2844:
2840:
2836:
2832:
2823:
2816:
2809:
2806:
2802:
2801:0-8493-0483-0
2798:
2794:
2789:
2786:
2781:
2777:
2773:
2769:
2765:
2761:
2757:
2751:
2749:
2745:
2740:
2736:
2733:(2): 187â96.
2732:
2728:
2721:
2718:
2713:
2709:
2704:
2699:
2694:
2689:
2685:
2681:
2680:
2675:
2668:
2666:
2662:
2657:
2653:
2648:
2643:
2639:
2635:
2632:(3): 561â90.
2631:
2627:
2623:
2621:
2615:
2611:
2608:Caldwell PC,
2604:
2601:
2596:
2592:
2587:
2582:
2578:
2574:
2570:
2566:
2562:
2560:
2556:
2550:
2546:
2540:
2538:
2534:
2529:
2523:
2519:
2512:
2509:
2505:
2500:
2497:
2492:
2488:
2484:
2480:
2476:
2472:
2469:(3): 265â73.
2468:
2464:
2457:
2454:
2450:
2445:
2442:
2438:
2433:
2431:
2427:
2421:
2418:
2412:
2409:
2397:
2393:
2389:
2385:
2381:
2377:
2370:
2363:
2360:
2355:
2351:
2346:
2341:
2337:
2333:
2328:
2323:
2319:
2315:
2311:
2304:
2301:
2296:
2292:
2288:
2286:9780815344322
2282:
2278:
2274:
2267:
2264:
2257:
2246:
2239:
2236:The signs of
2233:
2230:
2224:
2220:
2217:
2215:
2212:
2210:
2207:
2205:
2202:
2200:
2197:
2195:
2192:
2190:
2187:
2185:
2182:
2180:
2177:
2175:
2172:
2171:
2167:
2165:
2163:
2158:
2156:
2150:
2147:
2145:
2141:
2137:
2131:
2129:
2125:
2116:
2114:
2111:
2106:
2101:
2098:and far from
2094:
2089:
2084:
2075:
2071:
2067:
2064:
2060:
2055:
2048:
2041:
2036:
2035:Driving force
2033:
2032:
2031:
2025:
2022:
2021:
2020:
2017:
2009:
2007:
2005:
2001:
1997:
1991:
1988:
1984:
1980:
1976:
1967:
1963:
1960:
1955:
1953:
1944:
1942:
1938:
1936:
1931:
1927:
1923:
1917:
1913:
1909:
1904:
1882:
1856:
1829:
1825:
1805:
1778:
1774:
1754:
1733:
1710:
1683:
1679:
1656:
1629:
1625:
1602:
1581:
1574:
1569:
1566:
1561:
1557:
1554:
1548:
1543:
1539:
1531:
1530:
1529:
1527:
1522:
1520:
1516:
1512:
1507:
1499:
1497:
1479:
1475:
1468:
1463:
1459:
1456:
1452:
1443:
1436:
1434:
1432:
1429:and possibly
1428:
1424:
1420:
1416:
1415:chemoreceptor
1412:
1408:
1404:
1400:
1396:
1392:
1388:
1384:
1380:
1376:
1372:
1368:
1364:
1360:
1356:
1352:
1348:
1344:
1340:
1335:
1333:
1329:
1325:
1321:
1317:
1313:
1309:
1306:in excitable
1305:
1301:
1297:
1293:
1289:
1285:
1281:
1277:
1273:
1269:
1265:
1264:Na+/K+-ATPase
1261:
1257:
1253:
1249:
1245:
1241:
1236:
1234:
1227:
1219:
1217:
1215:
1211:
1207:
1202:
1198:
1190:
1188:
1183:
1176:
1164:
1161:
1154:
1151:
1147:
1143:
1140:
1137:
1133:
1130:
1127:
1123:
1119:
1116:
1113:
1109:
1105:
1102:
1100:
1093:
1090:
1089:
1088:
1066:
1056:
1052:
1041:
1031:
1027:
1017:
1014:
1008:
1005:
1000:
997:
991:
984:
980:
976:
973:
970:
966:
958:
957:
956:
954:
947:
942:
940:
936:
932:
924:
922:
919:
918:Andrew Huxley
915:
911:
906:
904:
900:
893:
891:
887:
885:
881:
873:
869:
868:AMPA receptor
865:
864:axon terminal
861:
857:
852:
844:
837:
835:
833:
828:
821:
819:
817:
813:
809:
805:
801:
796:
794:
789:
788:conformations
780:
776:
774:
769:
765:
757:
752:
748:
740:
738:
736:
731:
729:
723:
719:
715:
713:
709:
705:
700:
696:
691:
689:
685:
681:
676:
672:
663:
656:
654:
652:
648:
644:
640:
636:
629:
624:
617:
615:
613:
607:
605:
601:
596:
593:
592:lipid bilayer
589:
581:
580:semipermeable
576:
569:
567:
563:
561:
557:
552:
550:
546:
542:
538:
534:
530:
526:
522:
512:
507:
503:
499:
495:
487:
485:
481:
467:
456:
452:
447:
443:
438:
434:
433:
429:
424:
420:
416:
406:
401:
393:
391:
384:
382:
378:
376:
375:lipid bilayer
370:
366:
364:
360:
359:intracellular
356:
355:extracellular
352:
348:
344:
339:
337:
333:
329:
325:
317:
315:
311:
309:
305:
301:
297:
293:
288:
281:
279:
277:
273:
269:
263:
261:
257:
253:
249:
245:
241:
237:
233:
232:lipid bilayer
229:
221:
219:
217:
213:
209:
206:
201:
199:
195:
191:
190:cell membrane
187:
183:
179:
175:
171:
167:
138:
134:
124:
121:
113:
102:
99:
95:
92:
88:
85:
81:
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71: â
70:
66:
65:Find sources:
59:
55:
49:
48:
43:This article
41:
37:
32:
31:
19:
4001:
3986:
3972:
3958:
3943:
3928:
3907:. Retrieved
3901:
3891:
3879:. Retrieved
3873:
3863:
3851:. Retrieved
3847:the original
3842:
3833:
3821:. Retrieved
3817:ScienceAlert
3815:
3805:
3793:. Retrieved
3790:Blog Network
3786:
3776:
3751:
3747:
3741:
3711:(1): 36â41.
3708:
3704:
3698:
3663:
3659:
3649:
3624:
3620:
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3593:
3577:
3572:
3555:
3551:
3545:
3533:
3528:
3498:(1): 43â58.
3495:
3491:
3481:
3436:
3432:
3422:
3377:
3373:
3363:
3330:
3326:
3313:
3268:
3264:
3254:
3203:
3199:
3192:
3157:
3153:
3143:
3100:
3096:
3086:
3059:
3053:
3010:
3007:Neuroscience
3006:
2996:
2955:
2951:
2945:
2933:
2928:
2909:
2903:
2878:
2874:
2868:
2859:
2834:
2830:
2821:
2814:
2808:
2792:
2788:
2763:
2759:
2730:
2726:
2720:
2683:
2677:
2629:
2625:
2619:
2603:
2571:(1): 28â60.
2568:
2564:
2558:
2554:
2517:
2511:
2499:
2466:
2462:
2456:
2444:
2420:
2411:
2399:. Retrieved
2379:
2375:
2362:
2317:
2313:
2303:
2272:
2266:
2244:
2237:
2232:
2159:
2151:
2148:
2132:
2124:mitochondria
2120:
2107:
2099:
2092:
2090:
2082:
2079:
2066:Permeability
2065:
2053:
2046:
2039:
2034:
2029:
2015:
2013:
2010:Other values
1992:
1972:
1956:
1951:
1948:
1939:
1925:
1918:
1914:
1910:
1902:
1899:
1523:
1503:
1471:
1448:
1431:immune cells
1419:glomus cells
1417:cells (e.g.
1411:Merkel cells
1405:cells (e.g.
1395:pinealocytes
1353:), vascular
1336:
1324:progesterone
1237:
1229:
1194:
1181:
1174:
1171:
1162:·m or mmol·l
1141:
1134:= number of
1131:
1117:
1108:gas constant
1106:= universal
1103:
1091:
1086:
945:
943:
934:
928:
909:
907:
902:
897:
888:
860:postsynaptic
849:
825:
810:, such as a
803:
799:
797:
793:inactivation
792:
785:
764:Ion channels
762:
741:Ion channels
732:
724:
720:
716:
692:
678:
632:
608:
597:
585:
564:
553:
540:
532:
518:
482:
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439:
435:
427:
422:
414:
412:
388:
379:
371:
367:
340:
335:
321:
312:
289:
285:
276:muscle cells
267:
264:
256:ion channels
225:
202:
173:
169:
165:
164:
136:
116:
107:
97:
90:
83:
76:
64:
52:Please help
47:verification
44:
3717:10.1038/236
3160:(1): 1â52.
2837:: 581â646.
2138:when it is
1427:plant cells
1383:delta cells
1379:alpha cells
1244:electrolyte
1206:Glial cells
1201:development
747:Ion channel
463:, that is,
423:differences
334:called the
222:Description
110:August 2022
4057:Categories
4002:Physiology
3957:Hille, B.
3909:30 January
3903:nypost.com
3881:30 January
3853:30 January
3823:30 January
3795:30 January
3221:1807/90084
2756:Hodgkin AL
2686:: 588664.
2626:J. Physiol
2610:Hodgkin AL
2565:J. Physiol
2545:Hodgkin AL
2258:References
2160:A dose of
2140:fertilized
1478:RC circuit
1407:hair cells
1375:beta cells
1300:astrocytes
1240:regulators
1173:potential
832:rectifiers
533:monovalent
330:lead to a
157:The large
80:newspapers
3754:: 27â36.
3733:204995437
3580:, p. 34;
3455:0958-0670
3396:1664-3224
3333:: 73â82.
3287:1664-042X
3230:0008-4212
3176:0079-6107
3119:1040-452X
3078:762720374
3027:0306-4522
2972:1460-9568
2760:Biol. Rev
2614:Keynes RD
2549:Keynes RD
2506:, p. 483.
2336:1664-042X
2295:887605755
1857:−
1711:−
1570:
1359:pericytes
1330:modulate
1214:potassium
1018:
872:glutamate
712:magnesium
699:potassium
680:Ion pumps
657:Ion pumps
651:ion pumps
639:passively
604:capacitor
556:diffusion
529:potassium
527:(Na) and
498:Diffusion
419:Ohm's law
409:smallest.
349:(Na) and
343:potassium
260:batteries
198:radiation
3768:29029878
3725:10195106
3512:16685600
3473:28139019
3414:26257741
3355:52812190
3347:30243042
3305:27065884
3246:49679747
3238:29969572
3135:38314187
3127:20586098
3045:15561419
2988:30714579
2895:18045167
2780:86282580
2712:33716756
2656:13806926
2595:14368574
2551:(1955).
2491:22063907
2354:30519193
2320:: 1661.
2168:See also
1979:synapses
1484:, where
1425:), some
1347:skeletal
1328:estrogen
1150:coulombs
880:receptor
708:chloride
635:actively
600:resistor
545:chloride
541:divalent
455:gradient
351:chloride
270:such as
252:ion pump
236:proteins
228:membrane
3875:Newshub
3690:7807062
3681:2229225
3641:7720212
3603:Bullock
3597:Purves
3582:Bullock
3576:Purves
3564:5045041
3538:Bullock
3532:Purves
3464:5435930
3405:4512153
3380:: 375.
3296:4811949
3271:: 116.
3184:7001542
3036:2322935
2980:8261131
2938:Bullock
2932:Purves
2851:4885777
2703:7947867
2647:1363339
2586:1365754
2483:1664861
2449:Bullock
2437:Bullock
2345:6258788
2074:coulomb
2070:siemens
2016:resting
1975:neurons
1922:blowfly
1511:neurons
1490:R = 1/g
1343:cardiac
1320:adrenal
1316:Thyroid
1292:neurons
1126:kelvins
939:battery
728:ouabain
704:calcium
537:calcium
432:ground.
400:Voltage
394:Voltage
332:voltage
272:neurons
216:osmosis
94:scholar
4008:
3993:
3979:
3965:
3950:
3935:
3766:
3731:
3723:
3688:
3678:
3639:
3599:et al.
3578:et al.
3562:
3534:et al.
3520:849895
3518:
3510:
3471:
3461:
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3412:
3402:
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3293:
3285:
3244:
3236:
3228:
3182:
3174:
3133:
3125:
3117:
3076:
3066:
3043:
3033:
3025:
2986:
2978:
2970:
2934:et al.
2916:
2893:
2849:
2799:
2778:
2710:
2700:
2654:
2644:
2620:Loligo
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2583:
2559:Loligo
2524:
2489:
2481:
2401:1 June
2396:326151
2394:
2352:
2342:
2334:
2293:
2283:
1515:glands
1482:Ï = RC
1373:(e.g.
1351:smooth
1339:muscle
1262:(e.g.
1250:, Cl,
1197:neuron
1114:·K·mol
1112:joules
1087:where
525:sodium
504:, and
428:per se
347:Sodium
168:(also
159:purple
153:Orange
149:Yellow
145:Purple
96:
89:
82:
75:
67:
3839:"ć„łćć"
3729:S2CID
3516:S2CID
3351:S2CID
3323:(PDF)
3242:S2CID
3131:S2CID
2984:S2CID
2776:S2CID
2555:Sepia
2487:S2CID
2372:(PDF)
2225:Notes
2144:sperm
2142:by a
1399:glial
1210:brain
1099:volts
549:algae
234:with
208:volts
205:milli
101:JSTOR
87:books
4006:ISBN
3991:ISBN
3977:ISBN
3963:ISBN
3948:ISBN
3933:ISBN
3911:2023
3883:2023
3855:2023
3825:2023
3797:2023
3764:PMID
3721:PMID
3686:PMID
3637:PMID
3560:PMID
3508:PMID
3469:PMID
3451:ISSN
3410:PMID
3392:ISSN
3343:PMID
3301:PMID
3283:ISSN
3234:PMID
3226:ISSN
3180:PMID
3172:ISSN
3123:PMID
3115:ISSN
3074:OCLC
3064:ISBN
3041:PMID
3023:ISSN
2976:PMID
2968:ISSN
2914:ISBN
2891:PMID
2847:PMID
2797:ISBN
2708:PMID
2652:PMID
2591:PMID
2557:and
2522:ISBN
2479:PMID
2403:2024
2392:PMID
2350:PMID
2332:ISSN
2291:OCLC
2281:ISBN
2243:and
2162:salt
1409:and
1326:and
1286:and
1278:and
1231:and
1095:eq,K
933:(or
929:The
916:and
884:GABA
876:GABA
766:are
749:and
710:and
682:are
673:and
645:and
602:and
558:and
521:ions
468:= ââ
324:ions
274:and
240:ions
186:work
182:cell
141:Blue
73:news
3756:doi
3752:635
3713:doi
3676:PMC
3668:doi
3664:104
3629:doi
3500:doi
3496:209
3459:PMC
3441:doi
3437:102
3400:PMC
3382:doi
3335:doi
3291:PMC
3273:doi
3216:hdl
3208:doi
3162:doi
3105:doi
3031:PMC
3015:doi
3011:129
2960:doi
2883:doi
2839:doi
2768:doi
2735:doi
2698:PMC
2688:doi
2642:PMC
2634:doi
2630:152
2581:PMC
2573:doi
2569:128
2471:doi
2467:124
2384:doi
2340:PMC
2322:doi
2136:egg
2128:ATP
2062:mV.
2057:ion
1935:ATP
1492:net
1413:),
1397:),
1274:),
1160:mol
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637:or
494:Ion
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