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149 lines
3.3 KiB
149 lines
3.3 KiB
TITLE detailed model of Glycine receptors |
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COMMENT |
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----------------------------------------------------------------------------- |
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Kinetic model of Glycine-A receptors: Pascal Legendre (Mauthner Cell) |
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==================================== |
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C0--C1--C2--O1 |
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C3--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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----------------------------------------------------------------------------- |
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Modified Paul Manis, UNC Chapel Hill, 2009 |
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Name, pointer name, kinetics are range variables, and kinetic values |
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are estimated from VCN glycine receptors. |
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Note: This model does not have a desensitization state. |
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----------------------------------------------------------------------------- |
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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 GLYaPL |
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POINTER XMTR |
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RANGE C0, C1, C2, C3, O1, O2, Open |
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RANGE g, gmax, f1, f2 |
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RANGE Erev |
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RANGE kon, koff, a1, b1, a2, b2, r, d |
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RANGE CellType : 0 for bushy, 1 for stellate |
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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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CellType = 1 (1) : define cell type parameters |
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: Rates |
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: Stellate cell fit (1/1/10; excellent fit) |
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: kon = 0.0236 (/uM /ms) : binding |
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: koff = 2.4 (/ms) : unbinding |
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: a1 = 1.707 (/ms) : opening |
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: b1 = 8.95 (/ms) : closing |
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: a2 = 0.325 (/ms) : opening |
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: b2 = 5.871 (/ms) : closing |
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: r = 2.019 (/ms) : return from deep state |
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: d = 28.87 (/ms) : going to deep state |
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:if psdtype == 'glyfast': fit from 3/5/2010. error = 0.174 maxopen = 0.0385 |
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: See synapses.py |
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a1 = 1.000476 (/ms) : opening |
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a2 = 0.137903 (/ms) : opening |
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b1 = 1.700306 (/ms) : closing |
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koff = 13.143132 (/ms) : unbinding |
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kon = 0.038634 (/ms) : binding |
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r = 0.842504 (/ms) : return from deep state |
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b2 = 8.051435 (/ms) : closing |
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d = 12.821820 (/ms) : going to deep state |
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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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koff2 (/ms) |
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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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C3 : bound but closed state to O2 |
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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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XMTR = 0.0 |
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C0 = 1 |
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C1 = 0 |
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C2 = 0 |
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C3 = 0 |
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O1 = 0 |
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O2 = 0 |
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} |
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BREAKPOINT { |
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SOLVE kstates METHOD sparse |
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:VERBATIM |
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: if (CGly > 0.0) { |
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: fprintf(stderr, "t = %f Xmtr = %f\n", t, XMTR); |
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: } |
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: ENDVERBATIM |
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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 = 2.0 * kon * (1e3) * XMTR |
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f2 = kon * (1e3) * XMTR |
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koff2 = 2.0 * koff |
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~ C0 <-> C1 (f1,koff) |
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~ C1 <-> C2 (f2,koff2) |
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~ C2 <-> O1 (a1,b1) |
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~ C2 <-> C3 (d, r) |
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~ C3 <-> O2 (a2,b2) |
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CONSERVE C0+C1+C2+C3+O1+O2 = 1 |
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}
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