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147 lines
3.2 KiB
147 lines
3.2 KiB
TITLE detailed model of Glycine receptors |
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COMMENT |
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Kinetic model of Glycine-A receptors |
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==================================== |
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C -- C1 -- C2 |
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O1 O2 |
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----------------------------------------------------------------------------- |
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This mod file does not include mechanisms for the release and time course |
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of transmitter; it is to be used in conjunction with a sepearate mechanism |
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to describe the release of transmitter and that provides the concentration |
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of transmitter in the synaptic cleft (to be connected to pointer C here). |
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Based on models |
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Destexhe, A., Mainen, Z.F. and Sejnowski, T.J. Kinetic models of |
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synaptic transmission. In: Methods in Neuronal Modeling (2nd edition; |
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edited by Koch, C. and Segev, I.), MIT press, Cambridge, 1998, pp. 1-25. |
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(electronic copy available at http://cns.iaf.cnrs-gif.fr) |
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Written by Alain Destexhe, Laval University, 1995 |
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Modified Paul Manis, UNC Chapel Hill, 2009 |
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Changed name, pointer name, kinetics are range variables, and kinetic values |
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are estimated from VCN glycine receptors. |
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This model does not have a desensitization state. |
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ENDCOMMENT |
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INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} |
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NEURON { |
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POINT_PROCESS GLYa5 |
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POINTER XMTR |
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RANGE C0, C1, C2, O1, O2, Open |
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RANGE g, gmax, f1, f2 |
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RANGE Erev |
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RANGE kf1, kf2, kb1, kb2, a1, b1, a2, b2 |
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NONSPECIFIC_CURRENT i |
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} |
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UNITS { |
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(nA) = (nanoamp) |
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(mV) = (millivolt) |
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(pS) = (picosiemens) |
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(umho) = (micromho) |
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(mM) = (milli/liter) |
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(uM) = (micro/liter) |
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} |
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PARAMETER { |
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Erev = -70 (mV) : reversal potential |
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gmax = 500 (pS) : maximal conductance |
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: Rates |
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: from fits to averaged ipsc data, stellate cells 1/1/10 |
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: kf1 = 0.002930 (/uM /ms) : binding |
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: kf2 = 0.005936 (/uM /ms) : binding |
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: kb1 = 2.793 (/ms) : unbinding |
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: kb2 = 1.445 (/ms) : unbinding |
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: a1 = 1e-6 (/ms) : opening |
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: b1 = 129.0 (/ms) : closing |
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: a2 = 5.10 (/ms) : opening |
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: b2 = 2.79 (/ms) : closing |
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: from fits to averaged ipsc data, bushy cells 1/1/10 |
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kf1 = 0.0278 (/uM /ms) : binding |
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kf2 = 1e-6 (/uM /ms) : binding |
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kb1 = 0.000054 (/ms) : unbinding |
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kb2 = 0.000855 (/ms) : unbinding |
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a1 = 1e-6 (/ms) : opening |
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b1 = 129.0 (/ms) : closing |
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a2 = 5.10 (/ms) : opening |
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b2 = 2.79 (/ms) : closing |
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} |
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ASSIGNED { |
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v (mV) : postsynaptic voltage |
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i (nA) : current = g*(v - Erev) |
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g (pS) : conductance |
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XMTR (mM) : pointer to glycine concentration |
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f1 (/ms) : binding |
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f2 (/ms) : binding |
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Open (1) |
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} |
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STATE { |
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: Channel states (all fractions) |
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C0 : unbound |
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C1 : single bound |
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C2 : double bound |
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O1 : open |
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O2 : open |
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} |
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INITIAL { |
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C0 = 1 |
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C1 = 0 |
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C2 = 0 |
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O1 = 0 |
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O2 = 0 |
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XMTR = 0.0 |
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} |
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BREAKPOINT { |
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SOLVE kstates METHOD sparse |
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Open = (O1 + O2) |
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g = gmax * Open |
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i = (1e-6) * g * (v - Erev) |
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} |
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KINETIC kstates { |
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f1 = kf1 * (1e3) * XMTR |
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f2 = kf2 * (1e3) * XMTR |
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~ C0 <-> C1 (f1,kb1) |
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~ C1 <-> C2 (f2,kb2) |
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~ C1 <-> O1 (a1,b1) |
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~ C2 <-> O2 (a2,b2) |
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CONSERVE C0+C1+C2+O1+O2 = 1 |
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}
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