Unreferenced date March 2007 Postsynaptic potentials are changes in the membrane potential of the postsynaptic terminal of a chemical synapse . Postsynaptic potentials are membrane potential graded potentials ..., the membrane is said to be depolarization depolarized , as the potential comes closer to zero. This is an excitatory postsynapticpotential EPSP , as it brings the neuron s potential closer to its firing ... of negative charge, this moves the potential further from zero and is referred to as hyperpolarization . This is an inhibitory postsynapticpotential IPSP , as it changes the charge across the membrane ... large fluctuations in membrane potential. If the postsynaptic cell is sufficiently depolarized, an action ... is returned to its equilibrium potential. Algebraic summation Postsynaptic potentials are subject to summation ... two excitatory postsynaptic potentials, they combine so that the membrane potential is depolarized by the sum ... receives an excitatory postsynapticpotential, and then the presynaptic neuron fires again, creating ... Neuron Neurotransmission Postsynaptic Synapse End plate potential External links MeshName Postsynaptic ... biochemistry receptors on the postsynaptic terminal, which may be a neuron or a myocyte muscle cell in the case of a neuromuscular junction . These are collectively referred to as postsynaptic receptors, since they are on the membrane of the postsynaptic cell. The role of ions One way receptors ... to enter or leave the cell. It is these ions that alter the membrane potential. Ions are subject ... potential Equilibrium potentials equilibrium potential , which is the state where the diffusion ... potential, there is no longer a net movement of ions. Two important equations that can determine membrane potential differences based on ion concentrations are the Nernst equation Nernst Equation and the Goldman Equation . Relation to action potentials Neurons have a resting potential of about 70mV .... EPSPs and IPSPs are transient changes in the membrane potential, and EPSPs resulting from transmitter ... more details
Cleanup date March 2009 An inhibitory postsynapticpotential IPSP is a synaptic potential that decreases the chance that a future action potential will occur in a postsynaptic neuron or motoneuron . ref ... 2008. ref The opposite of an inhibitory postsynapticpotential is an excitatory postsynapticpotential ... which then bind to the postsynaptic receptors this induces a postsynaptic conductance change as ion channels open or close. An electrical current is generated which changes the postsynaptic membrane potential to create a more negative postsynapticpotential . Depolarization can also occur due ... potentials at either excitatory or inhibitory synapses. In general, a postsynapticpotential is dependent on the type and combination of receptor channel, reverse potential of the postsynaptic ... this determines whether or not the action potential at the presynaptic terminal will regenerate at the postsynaptic ... IPSPflowchart.jpg thumb 540px Flowchart describing how an inhibitory postsynapticpotential works ... postsynapticpotential. Equivalent EPSPs positive and IPSPs negative can cancel each other out ... also affect the inhibitory postsynapticpotential. Simple temporal summation of postsynaptic potentials ... keeps the postsynapticpotential more negative than the threshold and decreases the probability of the postsynaptic neuron completing an action potential. Glycine molecules and receptors work much ... receiving an action potential. These channels influence the amplitude and time course of postsynaptic ... by measuring the amplitude and time course of the inhibitory postsynapticpotential. The results showed ... title Glutamate mediates an inhibitory postsynapticpotential in dopamine neurons. journal Nature volume .... See also Excitatory postsynapticpotentialPostsynapticpotential GABA Glycine References reflist 2 Nervous system physiology DEFAULTSORT Inhibitory PostsynapticPotential Category Memory processes ... action potential. They can take place at all chemical synapses which use the secretion of neurotransmitters ... more details
complicate the interpretation. See also Inhibitory postsynapticpotential IPSP Postsynaptic ... Neurophysiology DEFAULTSORT Excitatory PostsynapticPotential de Exzitatorisches postsynaptisches ... an action potential. Image Synapse diag5.png thumb 300px The summation of these three EPSPs generates an action potential. In neuroscience , an excitatory postsynapticpotential EPSP is a temporary depolarization of postsynaptic membrane potential caused by the flow of positively charged ion s into the postsynaptic cell as a result of opening of ligand sensitive channels. They are the opposite of inhibitory postsynapticpotential s IPSPs , which usually result from the flow of negative ions into the cell or positive ions out of the cell. A postsynapticpotential is defined as excitatory if it makes it easier for the neuron to fire an action potential . EPSPs can also result from a decrease ... outflow. The flow of ions that causes an EPSP is an excitatory postsynaptic current EPSC . EPSPs ... patch of postsynaptic membrane, their combined effect is the sum of the individual EPSPs. Larger EPSPs result in greater membrane depolarization and thus increase the likelihood that the postsynaptic cell reaches the threshold for firing an action potential . Overview EPSPs in living cells are caused ... bind to neurotransmitter receptor receptors on the postsynaptic cell. Many of these receptors ... sodium into the cell, generating an excitatory postsynaptic current. This depolarizing current causes an increase in membrane potential, the EPSP. Excitatory molecules The neurotransmitter most often ... 117 26 year 1997 ref In the neuromuscular junction of vertebrates, EPP end plate potential s are mediated ... end plate potential is used since Katz studies were performed on the neuromuscular junction , the muscle ... electrode. This extracellular signal recorded from a population of neurons is the field potential ... potential named the population spike which corresponds to the population of cells firing action ... more details
File Postsynaptic density.jpg thumb Ultra structural analysis of synapses in the brainstem of wild type WT mice at embryonic day 18.5. Synapses of WT neurons in the pre B tzinger complex area exhibit presynaptic vesicles asterisks , a synaptic cleft and a distinct postsynaptic density arrowheads . Scale bar, 250 nm. From Heupel et al., 2008 The postsynaptic density PSD is a protein dense specialization attached to the postsynaptic membrane. PSDs were originally identified by electron microscopy as an electron dense region at the membrane of a postsynaptic neuron. The PSD is in close apposition ... in great detail at glutamatergic synapses. Hundreds of proteins have been identified in the postsynaptic ... of synaptic function. Key among these, are postsynaptic density 95 PSD95 , neuroligin a cellular adhesion ... display&start 1 Postsynaptic Density Cell Centered Database http molneuro.kaist.ac.kr psd The postsynaptic density http synapse web.org lab harris Lecture13 index.htm Molecular Composition of the Postsynaptic Density References General review cite journal author Ziff EB title Enlightening the postsynaptic ... at the postsynaptic density journal Science volume 290 issue 5492 pages 750 4 year 2000 month October ... G, Churchill L, Cotman CW title Proteins of the postsynaptic density journal J. Cell Biol. volume ... cite journal author Cohen RS, Blomberg F, Berzins K, Siekevitz P title The structure of postsynaptic ... 10.1083 jcb.74.1.181 cite journal author Blomberg F, Cohen RS, Siekevitz P title The structure of postsynaptic ..., Jensen ON, Mann M, Provance DW, Mercer JA, Kennedy MB title Identification of proteins in the postsynaptic ..., Sheng M title Semiquantitative proteomic analysis of rat forebrain postsynaptic density fractions by mass .... title Identification and verification of novel rodent postsynaptic density proteins journal Mol. Cell ... that may lie at the core of the postsynaptic density journal Science volume 311 issue 5760 pages ... complexes in the postsynaptic proteome journal J. Neurochem. volume 97 issue Suppl 1 pages ... more details
Dablink For other words or senses of this term, see potential disambiguation . In linguistics, the Irrealis mood Potentialpotential mood The mathematic al study of potentials is known as potential theory it is the study of harmonic function s on manifold s. This mathematical formulation arises from the fact that, in physics, the scalar potential is irrotational , and thus has a vanishing Laplacian the very definition of a harmonic function. In physics , a potential may refer to the scalar potential or to the vector potential . In either case, it is a field physics field defined in space, from which many important physical properties may be derived. Leading examples are the gravitational potential and the electric potential , from which the motion of gravitating or electrically charged bodies may be obtained. Specific forces have associated potentials, including the Coulomb potential , the van der Waals potential , the Lennard Jones potential and the Yukawa potential . In electrochemistry there are Galvani potential and Volta potential . In Thermodynamics potential refers to thermodynamic potential . See also Potential difference Potential energy Category Potential es Potencial de Potential fr Potentiel d un champ vectoriel ja pl Potencja ru sl Potencial sv Potential lt Potencialas ... more details
Unreferenced date December 2006 A synaptic potential also known as a postsynapticpotential is an alteration in the membrane potential of a cell resulting from activation of a chemical synapse synaptic input . All animal cells maintain a voltage difference between the intracellular and extracellular regions, holding the intracellular region at a negative voltage that in a baseline state is usually in the range 30 to 70 millivolts. Synaptic inputs from neuron s can alter this voltage difference. If the intracellular voltage rises, the signal is called an excitatory postsynapticpotential EPSP if it falls the signal is called an inhibitory postsynapticpotential IPSP . If the cell is electrically excitable, a sufficiently large EPSP may cause it to generate an action potential . Category Cell biology Neuroscience stub Medicine stub ... more details
Receptor potential , a type of graded potential , is the transmembrane potential difference of a sensory receptor . ref Cite book ref harv first Bertil last Hille authorlink Bertil Hille title Ion Channels of Excitable Membranes edition 3rd year 2001 publisher Sinauer location Sunderland, Massachusetts chapter Chapter 8. Sensory transduction and excitable cells. pages 237&ndash 268 isbn 0878933212 ref A receptor potential is often produced by sensory transduction . It is generally a depolarization depolarizing event resulting from inward current electricity current flow. The influx of current will often bring the membrane potential of the sensory receptor towards the threshold for triggering an action potential . A receptor potential is a form of graded potential. An example of this is in a taste bud , where taste is converted into an electrical signal sent to the brain. When stimulated the taste bud triggers the release of neurotransmitter through exocytosis of synaptic vesicles from the presynaptic membrane. The neurotransmitter molecules diffuse across the synaptic cleft to the postsynaptic membrane. Graded potentials vary in size. They arise from the summation of the individual actions of ligand gated ion channel proteins, and decrease over time and space. They are distinct from Voltage gated ion channel voltage gated sodium and potassium channels . ref Harvnb Hille 2001 pp 169&ndash 200 . Chapter 6. Ligand gated channels of fast chemical synapses. ref References reflist DEFAULTSORT Receptor Potential Category Receptors Category Electrophysiology de Rezeptorpotential id Potensial reseptor ... more details
excitatory postsynapticpotential excitatory and inhibitory postsynapticpotential s of such inputs ... postsynapticpotential s from a presynaptic neuron. ref name neurotransmission Theodore Holmes Bullock ... efforts can be thwarted, however, by the counter acting inhibitory postsynapticpotential s. Neurotransmission ...pp move vandalism small yes In physiology , an action potential is a short lasting event in which the electrical membrane potential of a Cell biology cell rapidly rises and falls, following a consistent ... function is to activate intracellular processes. In muscle cells, for example, an action potential ... . A neuron that emits an action potential is often said to fire . Action potentials are generated ... cite journal author Barnett MW, Larkman PM title The action potential journal Pract Neurol ... 192.short issn ref These channels are shut when the membrane potential is near the resting potential of the cell, but they rapidly begin to open if the membrane potential increases to a precisely defined ... the electrochemical gradient, which in turn produces a further rise in the membrane potential. This then causes ... potential. The rapid influx of sodium ions causes the polarity of the plasma membrane ... gradient to the resting state. After an action potential has occurred, there is a transient ... currents. This is the mechanism which prevents an action potential traveling back the way it just ... muscle contraction. Overview for a typical neuron Image Action potential vert.png thumb 300px Figure 1. A. view of an idealized action potential shows its various phases as the action potential ... used to make the recording. alt Two plots of the membrane potential measured in mV versus time ms . Top idealized plot where the membrane potential starts out at 70 mV at time zero. A stimulus is applied at time 1 ms, which raises the membrane potential above 55 mV the threshold potential . After the stimulus is applied, the membrane potential rapidly rises to a peak potential of 40 mV at time ... more details
of a synapse is called a postsynapticpotential . Neurotransmitter s that act to open sodium ... postsynapticpotential , or IPSP. When multiple types of channels are open within the same time period, their postsynaptic potentials summate. All other values of membrane potential From the viewpoint ...File Membrane potential ions en.svg thumb right 350px Differences in concentration of ion s on opposite sides of a plasma membrane cellular membrane produce a voltage difference called the membrane potential ... sometimes play an important role, are not shown. Membrane potential or transmembrane potential is the difference in voltage or electrical potential difference between the interior and exterior of a cell ... of a lipid bilayer with a variety of molecular structures embedded in it. The membrane potential arises .... The membrane potential has two basic functions. First, it allows a cell to function as a battery ... in the membrane produces a local change in the membrane potential, which causes electric current ... states, the membrane potential is held at a relatively stable value, called the resting potential . For neurons, typical values of the resting potential range from 70 to 80 millivolts that is, the interior .... Opening and closing of ion channels can induce a departure from the resting potential, called a depolarization ... potential , in which the membrane potential very rapidly undergoes a large change, often briefly ... s. In neurons, the factors that influence the membrane potential are diverse. They include numerous ... dependent ion channels are controlled by the membrane potential, while the membrane potential ... basis The membrane potential in a cell derives ultimately from two factors electrical force and diffusion .... Voltage , which is synonymous with electrical potential , is the ability to drive an electric current .... A major contribution to establishing the membrane potential is made by the Na K ATPase sodium ... subset function as neurotransmitter receptor s they occur at postsynaptic sites, and the chemical ... more details
Wiktionary potentialPotential may mean In mathematics and physics a Potential Scalar potential Vector potential A potential function , that is, a harmonic function studied in potential theory In physics and engineering Potential energy Magnetic potential Electric potential Electromagnetic four potential Coulomb potential van der Waals potential Lennard Jones potential Yukawa potential In linguistics Irrealis mood PotentialPotential mood In biology Action potential Membrane potential Water potential In Television Potential Buffy episode Potential Buffy episode , an episode of Buffy the Vampire Slayer Potential and new Slayers , characters in Buffy the Vampire Slayer Disambig cs Potenci l de Potential Begriffskl rung fr Potentiel it Potenziale he lt Potencialas ja ru simple Potential sv Potential ... more details
In mechanics , a pair potential is a function that describes the potential energy of two interacting objects. Examples of pair potentials include the Coulomb s law , Newton s law of universal gravitation , the Lennard Jones potential and the Morse potential . Pair potentials are very common in physics exceptions are very rare. An example of a potential energy function that is not a pair potential is the three body Axilrod Teller potential . Category Mechanics physics stub ... more details
Contact potential may refer to Contact electrification Galvani potential difference in electrochemistry, at a junction of two metals Volta potential difference in electrochemistry, between two points in vacuum near surfaces of two metals in contact Disambig ... more details
The term potential function may refer to A mathematical function mathematics function whose values are a physical potential . The class of functions known as harmonic function s, which are the topic of study in potential theory . The potential function of a potential game . A function used in the potential method of amortized analysis to describe an investment of resources by past operations that can be used by future operations. mathdab ... more details
A potential gradient is the local space derivative rate of change of the potential with respect to displacement. In electrostatics then, it is the local space rate of change of the electric potential math mathbf E delta V delta s math http niuhep.physics.niu.edu willis phys251 chapter 19 day 2.html Units are volt s per meter V m . The electric field is the same as the potential gradient but with opposite sign. In biology , potential gradient is the net difference in electric charge across a cell membrane . Category Electronics terms electronics stub pl Gradient potencja u ... more details
Volta potential also called Volta potential difference , or contact potential difference , or outer potential difference , , delta psi in electrochemistry , is the electric potential difference between two points 1 and 2 in the vacuum point 1 close to the surface of metal M sub 1 sub point 2 close to the surface of metal M sub 2 sub or electrolyte where M sub 1 sub and M sub 2 sub are two uncharged metals brought into contact. ref http www.iupac.org goldbook C01293.pdf IUPAC Gold Book, definition of contact Volta potential difference. ref The Volta potential is named after Alessandro Volta . Volta potential between two metals When two metals are electrically isolated from each other, an arbitrary potential difference may exist between them. However, when two different metals are brought into contact, electrons will flow from the metal with a lower work function to the metal with the higher work function until the electrochemical potential of the electrons in the bulk of both phases are equal. The actual numbers of electrons that passes between the two phases is small, and the occupancy of the Fermi level s is practically unaffected. Measurement of Volta potential The Volta potential difference is measurable. It is related to the capacitance of an electrostatic capacitor , the two sides of which are made of the two metals for which the Volta potential difference is measured and the electrical charge used to load the capacitor. The Volta potential difference between a metal and an electrolyte can be measured in a similar fashion. ref V.S. Bagotsky, Fundamentals of Electrochemistry , Willey Interscience, 2006. ref See also Electrode potential Absolute electrode potential Electrical potential Galvani potentialPotential difference voltage Volt References reflist physics stub Category Electrochemistry Category Potential ca Potencial Volta de Volta Spannung es Potencial Volta it Potenziale Volta pl Potencja Volty uk ... more details
Definition The potential of something to grow. Overview In the case of a company, it is its potential to grow larger in terms of market capitalization , Production, costs, and pricing production , sales , revenue , employment , or management . In the case of living creatures, they initially have more growth potential than later on. Category Business terms business stub ... more details
Cleanup date February 2008 Unreferenced date February 2008 Biotic potential is the maximum reproductive capacity of a population if resources are unlimited. Full expression of the biotic potential of an organism is restricted by environmental resistance , any condition that inhibits the increase in number of the population. It is generally only reached when environmental conditions are very favorable. A species reaching its biotic potential would exhibit exponential population growth and be said to have a high fertility , that is, how many offspring are produced per mother. Biotic Potential is a fundamental species characteristic, defined by Chapman 1925 as the inherent power of organisms to reproduce and survive ref Chapman, R. N., 1925. Animal Ecology with Special Reference to Insects. Burgess Brook Inc.,Minneapolis. 370 pp. See pp.158 161. ref . In 1931, Chapman redescribed it as It is a sort of algebraic sum of the number of young produced at each reproduction, number of reproductions ... to a vital index Vital Index number of births number of deaths 100 Biotic potential is the highest ... mortality rate. Significance of Biotic Potential If the potential value of population increase can ... potentialpotential increase and subtract the actual or observed value of decrease this difference ... potential. Components of Biotic Potential Reproductive potentialpotential natality It is the upper limit to biotic potential in the absence of mortality Survival potential Because reproductive potential does not account for the number of gametes surviving, survival potential is a necessary component of biotic potential it is the reciprocal of Death mortality in the absence of mortality, biotic potential reproductive potential Chapman identified two components nutritive potential the ability to acquire and utilize food for growth and energy protective potentialpotential ability of the organism ... mating care of young Graham Moss References references DEFAULTSORT Biotic Potential Category Reproduction ... more details
Electrode potential , E , in electrochemistry , according to an IUPAC definition, ref IUPAC. Compendium of Chemical Terminology , 2nd ed. the Gold Book . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford 1997 . XML on line corrected version http goldbook.iupac.org ... 10.1351 goldbook. http goldbook.iupac.org E01956.html Entry Electrode Potential ref is the electromotive ... electrode , and on the right hand side is the electrode the potential of which is being defined ... hydrogen electrode potential of 0 by convention , one obtains E sub Cell sub E sub Right ... potential is measured in volt s V . Measurement Image Three electrode setup.png thumb right Three electrode setup for measurement of electrode potential. The measurement is generally conducted using ... electrode standard hydrogen electrode or an equivalent The measured potential of the working ... potential , or a potential with a non zero net reaction on the working electrode but zero net current corrosion potential , Mixed potential theory mixed potential , or a potential with a non zero ... , or by using an electrolyte of sufficiently high Conductivity electrolytic conductivity . The potential ... electrode and the negative terminal to the reference electrode. Potential difference of a cell ... potential See also Electrolytic cell Anode and cathode definitions depend on charge and discharge Potential of a cell assembled of two electrodes can be determined from the two individual electrode ... potential difference of a galvanic cell, ref IUPAC Gold Book. Definition of the potential difference of a galvanic cell. http goldbook.iupac.org E01934.html ref according to which the electric potential ... electrode potential Absolute electrode potential Table of standard electrode potentials Electrical potential Galvani potentialPotential difference voltage References references DEFAULTSORT Electrode Potential Category Electrochemistry ca Potencial d el ctrode de Elektrodenpotential et Elektroodipotentsiaal ... more details
In mathematics , the Bessel potential is a potential theory potential similar to the Riesz potential but with better decay properties at infinity. If s is a complex number with positive real part then the Bessel potential of order s is the operator math I Delta s 2 math where is the Laplace operator and the fractional calculus fractional power is defined using Fourier transforms. See also Riesz potential Fractional integration Sobolev space Fractional Schr dinger equation References eom id B b110420 title Bessel potential operator first R. last Duduchava Citation last1 Grafakos first1 Loukas title Modern Fourier analysis publisher Springer Verlag location Berlin, New York edition 2nd series Graduate Texts in Mathematics isbn 978 0 387 09433 5 doi 10.1007 978 0 387 09434 2 id MathSciNet id 2463316 year 2009 volume 250 eom id B b120170 title Bessel potential space first L.I. last Hedberg eom id B b015870 first E.D. last Solomentsev citation first Elias last Stein authorlink Elias Stein title Singular integrals and differentiability properties of functions publisher Princeton University Press location Princeton, NJ year 1970 isbn 0 691 08079 8 Category Fractional calculus Category Partial differential equations Category Potential theory Category Singular integrals ... more details
multiple issues confusing June 2010 unreferenced June 2010 The endocochlear potential is the main resting potential in the cochlea . It is a positive direct current of 80mV which can be recorded from the endolymph with electrodes. When a sound is presented, the endocochlear potential changes either positive or negative in the endolymph , depending on the stimulus. The change in the potential is called the summating potential . With the movement of the basilar membrane , a shear force is created and a small potential is generated due to a difference in potential between the endolymph scala media 80 mV and the perilymph vestibular and tympanic ducts 70 mV . An acoustic stimulus produces a simultaneous change in conductance at the membrane of the receptor cell. Because there is a steep gradient 150 mV, changes in membrane conductance are accompanied by rapid influx and efflux of ions which in turn produce the receptor potential. This is known as the Battery Hypothesis. The receptor potential for each hair cell causes a release of neurotransmitter at its basal pole, which elicits excitation of the afferent nerve fibres. Category Anatomy ... more details
Galvani potential also called Galvani potential difference, or inner potential difference, , delta phi in electrochemistry , is the electric potential difference between two points in the bulk of two phases. ref http www.iupac.org goldbook G02574.pdf IUPAC Gold Book, definition of Galvani potential ... and a liquid e.g., a metal electrode submerged in an electrolyte . Generally, the Galvani potential ... The Galvani potential is named after Luigi Galvani . Galvani potential between two metals First, consider the Galvani potential between two metals. When two metals are electrically isolated from each other, an arbitrary potential difference may exist between them. However, when two different metals ... to the metal with the higher work function until the electrochemical potential of the electrons in the bulk ... potential between the two different phases in contact can be written as math overline mu j 1 overline mu j 2 math where math overline mu math is the electrochemical potential j denotes the species ... denote phase 1 and phase 2, respectively. Now, the electrochemical potential of a species is defined as a sum of its chemical potential and the local electrostatic potential math overline mu j mu j z j F phi math where is the chemical potential z is the electrical charge carried by a single charge carrier unity for electrons F is the Faraday constant is the electrostatic potential From the two ... hand side is the Galvani potential difference between the phases 1 and 2 . Thus, the Galvani potential ... of the chemical potential of the charge carriers in the two phases. The Galvani potential difference ... potential The Galvani potential difference is not measurable. The measured potential difference between ... of the two metals or their combination with the solution Galvani potential because the cell needs ... cell potential can be written as ref name Trasatti Sergio Trasatti, The Absolute Electrode Potential an Explanatory Note Recommendations 1986 , International Union of Pure and Applied Chemistry ... more details
Electromagnetism cTopic Electrostatics In classical electromagnetism , the electric potential denoted by , sub E sub or V also called the electrostatic potential at a point in space is the electric potential energy divided by electric charge charge associated with a static time invariant electric field . Typically measured in volt s, the electric potential is a scalar physics scalar quantity equivalent to a joule per coulomb . There is also a generalized electric scalar potential that is used ... potential cannot be simply interpreted as the ratio of potential energy to charge, however. Introduction ... field. Classical mechanics explores the concepts such as Force physics force , energy , potential etc. in more detail. Force and potential energy are directly related. As an object moves in the direction that the force accelerates it, its potential energy decreases. For example, the gravitational potential energy of a cannonball at the top of a hill is greater than at the base of the hill. As the object falls, that potential energy decreases and is translated to motion, or inertial kinetic energy. For certain forces, it is possible to define the potential of a field such that the potential .... The potential of an electric field is called the electric potential. The synonymous term electrostatic potential is also in common use. The electric potential and the magnetic vector potential together form a four vector , so that the two kinds of potential are mixed under Lorentz transformation s. In electrostatics The electric potential at a point r in a static electric field E is given by the line ... is an arbitrary path connecting the point with zero potential to r . When the Curl mathematics curl ... and determined by the gradient of the potential math mathbf E mathbf nabla V mathbf E . , math Then, by Gauss s law , the potential satisfies Poisson s equation math mathbf nabla cdot mathbf E mathbf ... potential is closely linked with potential energy . A test charge q has an electric potential ... more details
Image Action potential vert.png thumb 350px A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane . B. Actual recordings of action potentials are often distorted compared to the schematic view because of variations in electrophysiology electrophysiological techniques used to make the recording. The threshold potential is the membrane potential to which a membrane must be depolarization depolarized to initiate an action potential . It often can be between 40 and 55 volt mV , but it can vary based upon several factors. If ion channel s are available, that will move the potential in the direction of the equilibrium potential for that ion sodium ion channel Na sup sup is approximately 55mV potassium channel K sup sup is approximately 95mV chloride channel Cl sup sup is approximately 90mV Therefore, resting ion channel for sodium will depolarization depolarize and thus excite, while channels for potassium or chloride will hyperpolarization biology hyperpolarize and thus inhibit. External links eMedicineDictionary threshold stimulus GeorgiaPhysiology 1 1ch4 s1ch4 8 http www.cameron.edu gabrielr PHYCH4 sld013.htm Description at cameron.edu http www.ncbi.nlm.nih.gov books bv.fcgi?rid mcb.figgrp.6213 Diagram at nih.gov neuro stub Category Electrophysiology de Schwellenpotential pl Potencja progowy ... more details
Unreferenced date March 2009 A velocity potential is used in fluid dynamics , when a fluid occupies a simply connected region and is irrotational . In such a case, math nabla times mathbf u 0, math where math mathbf u math denotes the flow velocity of the fluid. As a result, math mathbf u math can be represented as the gradient of a scalar field scalar function math Phi math math mathbf u nabla Phi math , math Phi math is known as a velocity potential for math mathbf u math . A velocity potential is not unique. If math a math is a constant then math Phi a math is also a velocity potential for math mathbf u math . Conversely, if math Psi math is a velocity potential for math mathbf u math then math Psi Phi b math for some constant math b math . In other words, velocity potentials are unique up to a constant. Unlike a stream function , a velocity potential can exist in three dimensional flow. See also Hamiltonian fluid mechanics Potential flow DEFAULTSORT Velocity Potential Category Fluid dynamics Category Equations of fluid dynamics Fluiddynamics stub zh ... more details
Orphan date September 2008 Expressive potential is the degree to which a given MIDI controller music control interface input device enables a musician to control musical expression . An interface with low expressive potential enables control over a narrow range of musical expression, no matter how virtuoso virtuosic its player, whereas an interface with high expressive potential enables control over a wide range of musical expression. Expressive potential is independent of how that potential was, is, or will be realized in any given composition or performance. This independence allows the expressive potential of new musical instruments & interfaces to be compared and contrasted objectively with traditional musical instruments. The concept of expressive potential is closely related to the concept of affordance , i.e. all action possibilities latent in the environment, objectively measurable and independent of the individual s ability to recognize or realize them. One possible metric for expressive potential is the number of Degrees of freedom physics and chemistry degrees of freedom provided by the interface. The more degrees of freedom, the more independent expressive variables a musician can control independently during performance. The development of new interfaces to control musical expression is an active research area, supporting an annual conference, http nime.org New Interfaces for Musical Expression . Category Electronic music ... more details
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