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Cable Theory
In neuroscience, classical cable theory uses mathematical models to calculate the electric current (and accompanying voltage) along passive neurites, particularly the dendrites that receive synaptic inputs at different sites and times. Estimates are made by modeling dendrites and axons as cylinders composed of segments with capacitances c_m and resistances r_m combined in parallel (see Fig. 1). The capacitance of a neuronal fiber comes about because electrostatic forces are acting through the very thin lipid bilayer (see Figure 2). The resistance in series along the fiber r_l is due to the axoplasm's significant resistance to movement of electric charge. History Cable theory in computational neuroscience has roots leading back to the 1850s, when Professor William Thomson (later known as Lord Kelvin) began developing mathematical models of signal decay in submarine (underwater) telegraphic cables. The models resembled the partial differential equations used by Fourier to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cable Theory Neuron RC Circuit V3
Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a helix ** Arresting cable, part of a system used to rapidly decelerate an aircraft as it lands ** Bowden cable, a mechanical cable for transmitting forces * Rope generally, especially a thick, heavy ("cable laid") variety Transmission * Electrical cable, an assembly of one or more wires which may be insulated, used for transmission of electrical power or signals ** Coaxial cable, an electrical cable comprising an inner conductor surrounded by a flexible, tubular insulating layer, coated or surrounded by a tubular conducting shield ** Power cable, a cable used to transmit electrical power ** Submarine communications cable, a cable laid on the sea bed to carry telecommunication signals between land-based stations * Fiber-optic cable, a cable co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuronal
A neuron (American English), neurone (British English), or nerve cell, is an excitable cell that fires electric signals called action potentials across a neural network in the nervous system. They are located in the nervous system and help to receive and conduct impulses. Neurons communicate with other cells via synapses, which are specialized connections that commonly use minute amounts of chemical neurotransmitters to pass the electric signal from the presynaptic neuron to the target cell through the synaptic gap. Neurons are the main components of nervous tissue in all animals except sponges and placozoans. Plants and fungi do not have nerve cells. Molecular evidence suggests that the ability to generate electric signals first appeared in evolution some 700 to 800 million years ago, during the Tonian period. Predecessors of neurons were the peptidergic secretory cells. They eventually gained new gene modules which enabled cells to create post-synaptic scaffolds and ion cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Differential Equation
In mathematics, a partial differential equation (PDE) is an equation which involves a multivariable function and one or more of its partial derivatives. The function is often thought of as an "unknown" that solves the equation, similar to how is thought of as an unknown number solving, e.g., an algebraic equation like . However, it is usually impossible to write down explicit formulae for solutions of partial differential equations. There is correspondingly a vast amount of modern mathematical and scientific research on methods to numerically approximate solutions of certain partial differential equations using computers. Partial differential equations also occupy a large sector of pure mathematical research, in which the usual questions are, broadly speaking, on the identification of general qualitative features of solutions of various partial differential equations, such as existence, uniqueness, regularity and stability. Among the many open questions are the existence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohm's Law
Ohm's law states that the electric current through a Electrical conductor, conductor between two Node (circuits), points is directly Proportionality (mathematics), proportional to the voltage across the two points. Introducing the constant of proportionality, the Electrical resistance, resistance, one arrives at the three mathematical equations used to describe this relationship: V = IR \quad \text\quad I = \frac \quad \text\quad R = \frac where is the current through the conductor, ''V'' is the voltage measured across the conductor and ''R'' is the electrical resistance, resistance of the conductor. More specifically, Ohm's law states that the ''R'' in this relation is constant, independent of the current. If the resistance is not constant, the previous equation cannot be called ''Ohm's law'', but it can still be used as a definition of Electrical resistance and conductance#Static and differential resistance, static/DC resistance. Ohm's law is an empirical law, empirical rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Electrical Resistance
Specific may refer to: * Specificity (other) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the final verdict * Specific jurisdiction over an out-of-state party, specific to cases that have a substantial connection to the party's in-state activity * Order of specific performance, court order to perform a specific act Economics, finance, and accounting * Asset specificity, the extent to which the investments made to support a particular transaction have a higher value to that transaction than they would have if they were redeployed for any other purpose * Specific identification (inventories), summing purchase costs of all inventory items * Specific rate duty, duty paid at a specific amount per unit * Specific risk, risk that affects a very small number of assets Psychology * Domain specificity, theory that many aspects of cognition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farad
The farad (symbol: F) is the unit of electrical capacitance, the ability of a body to store an electrical charge, in the International System of Units, International System of Units (SI), equivalent to 1 coulomb per volt (C/V). It is named after the English physicist Michael Faraday (1791–1867). In SI base units 1 F = 1 kilogram, kg−1⋅meter, m−2⋅second, s4⋅ampere, A2. Definition The capacitance of a capacitor is one farad when one coulomb of charge changes the potential between the plates by one volt. Equally, one farad can be described as the capacitance which stores a one-coulomb charge across a potential difference of one volt. The relationship between capacitance, charge, and potential difference is linear. For example, if the potential difference across a capacitor is halved, the quantity of charge stored by that capacitor will also be halved. For most applications, the farad is an impractically large unit of capacitance. Most electrical and electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilfrid Rall
Wilfrid Rall (August 29, 1922 – April 1, 2018) was a neuroscientist who spent most of his career at the National Institutes of Health. He is considered one of the founders of computational neuroscience, and was a pioneer in establishing the integrative functions of neuronal dendrites. Rall developed the use of cable theory in neuroscience, as well as passive and active compartmental modeling of the neuron. Rall studied physics at Yale University, from which he graduated with highest honors in 1943, and where he was Chairman of the Yale Political Union's Labor Party.''The History of Neuroscience in Autobiography''. Ed. Squire, Larry R. Volume 5. Academic Press, 1996. 553. He was involved with the Manhattan Project at the University of Chicago during the war, and subsequently worked with K.S. Cole at Woods Hole. He then moved to the University of Otago in Dunedin to work with John Carew Eccles for his PhD, and remained there after Eccles' departure for Australia. In 1954, he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Neuron Model
Biological neuron models, also known as spiking neuron models, are mathematical descriptions of the conduction of electrical signals in neurons. Neurons (or nerve cells) are electrically excitable cells within the nervous system, able to fire electric signals, called action potentials, across a neural network. These mathematical models describe the role of the biophysical and geometrical characteristics of neurons on the conduction of electrical activity. Central to these models is the description of how the membrane potential (that is, the difference in electric potential between the interior and the exterior of a biological cell) across the cell membrane changes over time. In an experimental setting, stimulating neurons with an electrical current generates an action potential (or spike), that propagates down the neuron's axon. This axon can branch out and connect to a large number of downstream neurons at sites called synapses. At these synapses, the spike can cause the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Eccles (neurophysiologist)
Sir John Carew Eccles (27 January 1903 – 2 May 1997) was an Australian neurophysiologist and philosopher who won the 1963 Nobel Prize in Physiology or Medicine for his work on the synapse. He shared the prize with Andrew Huxley and Alan Lloyd Hodgkin. Life and work Early life Eccles was born in Melbourne, Australia. He grew up there with his two sisters and his parents: William and Mary Carew Eccles (both teachers, who home schooled him until he was 12). He initially attended Warrnambool High School originally published in ''Historical Records of Australian Science'', vol.13, no.4, 2001. (now Warrnambool College) (where a science wing is named in his honour), then completed his final year of schooling at Melbourne High School. Aged 17, he was awarded a senior scholarship to study medicine at the University of Melbourne. As a medical undergraduate, he was never able to find a satisfactory explanation for the interaction of mind and body; he started to think about becoming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrites
A dendrite (from Greek δένδρον ''déndron'', "tree") or dendron is a branched cytoplasmic process that extends from a nerve cell that propagates the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimulation is transmitted onto dendrites by upstream neurons (usually via their axons) via synapses which are located at various points throughout the dendritic tree. Dendrites play a critical role in integrating these synaptic inputs and in determining the extent to which action potentials are produced by the neuron. Structure and function Dendrites are one of two types of cytoplasmic processes that extrude from the cell body of a neuron, the other type being an axon. Axons can be distinguished from dendrites by several features including shape, length, and function. Dendrites often taper off in shape and are shorter, while axons tend to maintain a constant radius and can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurons
A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural network in the nervous system. They are located in the nervous system and help to receive and conduct impulses. Neurons communicate with other cells via synapses, which are specialized connections that commonly use minute amounts of chemical neurotransmitters to pass the electric signal from the presynaptic neuron to the target cell through the synaptic gap. Neurons are the main components of nervous tissue in all Animalia, animals except sponges and placozoans. Plants and fungi do not have nerve cells. Molecular evidence suggests that the ability to generate electric signals first appeared in evolution some 700 to 800 million years ago, during the Tonian period. Predecessors of neurons were the peptidergic secretory cells. They eventually ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rafael Lorente De Nó
Rafael Lorente de Nó (April 8, 1902 – April 2, 1990) was a Spanish neuroscientist who advanced the scientific understanding of the nervous system with his seminal research. He was a member of the National Academy of Sciences. The National Academies Press called him "one of the premier neurophysiologists in the United States". Life and career Lorente de Nó was born in Zaragoza, Spain. He received his medical degree from the University of Madrid in 1923. He immigrated to the United States in 1931 when he accepted a position at the Central Institute for the Deaf in St. Louis. In 1936, he joined The Rockefeller University, then known as The Rockefeller Institute for Medical Research, as an associate. He was made an associate member in 1938 and a full member in 1941. Lorente de Nó was an active member of several academic societies, among them the American Physiological Society and the American Association of Anatomists. Awards and distinctions Lorente de Nó was elected to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
