//genesis //Tabchannel implementation of conductances based on Traub et al. (2003): Fast rhythmic bursting can be induced in layer 2/3 cortical neurons by enhancing persistent Na+ conductance or by blocking BK channels. float tab_xmin = -0.10 float tab_xmax = 0.05 int tab_xdivs = 149 float cai_min = 1.0 float cai_max = 300 int i float x,dx,dx_h,XA,XB,Xinf,Xtau,YA,YB,Yinf,Ytau, ZA, ZB, Zinf, Ztau,dcai, cai dx = (tab_xmax-tab_xmin)/tab_xdivs dcai = (cai_max-cai_min)/tab_xdivs // only used for proto channels float GNa = 1 float GCa = 1 float GK = 1 float GH = 1 float ENa = 0.050 float ECa = 0.125 float EK = -0.09 float EH = -0.035 /* Transient Na conductance*/ create tabchannel T03_NaF setfield T03_NaF Ek {ENa} Gbar {GNa} Ik 0 Gk 0 Xpower 3 Ypower 1 Zpower 0 call T03_NaF TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} call T03_NaF TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) if ( x <= -0.032 ) Xtau = 0.0125e-3 + (0.007e-3 * {exp {(x + 0.030)/0.008}}) else Xtau = 0.01e-3 + (0.0725e-3 * {exp {(-x - 0.030)/0.008}}) end Xinf = 1/(1 + {exp {(-x - 0.038)/0.008}}) Ytau = 0.75e-3 + (5.75e-3/(1 + {exp {(x + 0.0335)/0.01}})) Yinf = 1/(1 + {exp {(x + 0.0574)/0.007}}) setfield T03_NaF X_A->table[{i}] {Xtau} setfield T03_NaF X_B->table[{i}] {Xinf} setfield T03_NaF Y_A->table[{i}] {Ytau} setfield T03_NaF Y_B->table[{i}] {Yinf} x = x + dx end setfield T03_NaF X_A->calc_mode 1 setfield T03_NaF X_B->calc_mode 1 setfield T03_NaF Y_A->calc_mode 1 setfield T03_NaF Y_B->calc_mode 1 tweaktau T03_NaF X tweaktau T03_NaF Y call T03_NaF TABFILL X 3000 0 call T03_NaF TABFILL Y 3000 0 /* Persistant Na conductance*/ create tabchannel T03_NaP setfield T03_NaP Ek {ENa} Gbar {GNa} Ik 0 Gk 0 Xpower 1 Ypower 0 Zpower 0 call T03_NaP TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) if ( x <= -0.027 ) Xtau = 0.025e-3 + (0.014e-3 * {exp {(x + 0.027)/0.01}}) else Xtau = 0.02e-3 + (0.145e-3 * {exp {(-x - 0.027)/0.01}}) end Xinf = 1/(1 + {exp {(-x - 0.035)/0.01}}) setfield T03_NaP X_A->table[{i}] {Xtau} setfield T03_NaP X_B->table[{i}] {Xinf} x = x + dx end setfield T03_NaP X_A->calc_mode 1 setfield T03_NaP X_B->calc_mode 1 tweaktau T03_NaP X call T03_NaP TABFILL X 3000 0 /* Delayed rectifier potassium conductance*/ create tabchannel T03_KDr setfield T03_KDr Ek {EK} Gbar {GK} Ik 0 Gk 0 Xpower 4 Ypower 0 Zpower 0 call T03_KDr TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) if ( x <= -0.010 ) Xtau = 0.75e-3 + (13.05e-3 * {exp {(x + 0.01)/0.01}}) else Xtau = 0.75e-3 + (13.05e-3 * {exp {(-x - 0.01)/0.01}}) end Xinf = 1/(1 + {exp {(-x - 0.0295)/0.01}}) setfield T03_KDr X_A->table[{i}] {Xtau} setfield T03_KDr X_B->table[{i}] {Xinf} x = x + dx end setfield T03_KDr X_A->calc_mode 1 setfield T03_KDr X_B->calc_mode 1 tweaktau T03_KDr X call T03_KDr TABFILL X 3000 0 /* Transient A-type potassium conductance*/ create tabchannel T03_KA setfield T03_KA Ek {EK} Gbar {GK} Ik 0 Gk 0 Xpower 4 Ypower 1 Zpower 0 call T03_KA TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} call T03_KA TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) Xtau = 0.185e-3 + (0.5e-3/({exp {(x + 0.0358)/0.0197}} + {exp {(-x - 0.0797)/0.0127}})) Xinf = 1/(1 + {exp {(-x - 0.060)/0.0085}}) if ( x <= -0.063 ) Ytau = 0.5e-3/({exp {(x + 0.046)/0.005}} + {exp {(-x - 0.238)/0.0375}}) else Ytau= 9.5e-3 end Yinf = 1/(1 + {exp {(x + 0.078)/0.006}}) setfield T03_KA X_A->table[{i}] {Xtau} setfield T03_KA X_B->table[{i}] {Xinf} setfield T03_KA Y_A->table[{i}] {Ytau} setfield T03_KA Y_B->table[{i}] {Yinf} x = x + dx end setfield T03_KA X_A->calc_mode 1 setfield T03_KA X_B->calc_mode 1 setfield T03_KA Y_A->calc_mode 1 setfield T03_KA Y_B->calc_mode 1 tweaktau T03_KA X tweaktau T03_KA Y call T03_KA TABFILL X 3000 0 call T03_KA TABFILL Y 3000 0 /* K2-type potassium conductance*/ create tabchannel T03_K2 setfield T03_K2 Ek {EK} Gbar {GK} Ik 0 Gk 0 Xpower 1 Ypower 1 Zpower 0 call T03_K2 TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} call T03_K2 TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) Xtau = 4.95e-3 + (0.5e-3/({exp {(x + 0.081)/0.0256}} + {exp {(-x - 0.132)/0.018}})) Xinf = 1/(1 + {exp {(-x - 0.010)/0.017}}) Ytau = 60e-3 + (0.5e-3/({exp {(x + 0.00133)/0.2}} + {exp {(-x - 0.130)/0.0071}})) Yinf = 1/(1 + {exp {(x + 0.058)/0.0106}}) setfield T03_K2 X_A->table[{i}] {Xtau} setfield T03_K2 X_B->table[{i}] {Xinf} setfield T03_K2 Y_A->table[{i}] {Ytau} setfield T03_K2 Y_B->table[{i}] {Yinf} x = x + dx end setfield T03_K2 X_A->calc_mode 1 setfield T03_K2 X_B->calc_mode 1 setfield T03_K2 Y_A->calc_mode 1 setfield T03_K2 Y_B->calc_mode 1 tweaktau T03_K2 X tweaktau T03_K2 Y call T03_K2 TABFILL X 3000 0 call T03_K2 TABFILL Y 3000 0 /* Low voltage threshold calcium conductance*/ create tabchannel T03_CaT setfield T03_CaT Ek {ECa} Gbar {GCa} Ik 0 Gk 0 Xpower 2 Ypower 1 Zpower 0 call T03_CaT TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} call T03_CaT TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) Xtau = 0.204e-3 + (0.333e-3/({exp {(x + 0.0158)/0.0182}} + {exp {(-x - 0.131)/0.0167}})) Xinf = 1/(1 + {exp {(-x - 0.056)/0.0062}}) if ( x <= -0.081 ) Ytau = 0.333e-3 * {exp {(x + 0.466)/0.0666}} else Ytau = 9.32e-3 + (0.333e-3 * {exp {(-x - 0.021)/0.0105}}) end Yinf = 1/(1 + {exp {(x + 0.085)/0.004}}) setfield T03_CaT X_A->table[{i}] {Xtau} setfield T03_CaT X_B->table[{i}] {Xinf} setfield T03_CaT Y_A->table[{i}] {Ytau} setfield T03_CaT Y_B->table[{i}] {Yinf} x = x + dx end setfield T03_CaT X_A->calc_mode 1 setfield T03_CaT X_B->calc_mode 1 setfield T03_CaT Y_A->calc_mode 1 setfield T03_CaT Y_B->calc_mode 1 tweaktau T03_CaT X tweaktau T03_CaT Y call T03_CaT TABFILL X 3000 0 call T03_CaT TABFILL Y 3000 0 /* Anomalous rectifier conductance H*/ create tabchannel T03_H setfield T03_H Ek {EH} Gbar {GH} Ik 0 Gk 0 Xpower 1 Ypower 0 Zpower 0 call T03_H TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) Xtau = 1e-3/({exp {(-14.6 - 86*x)}} + {exp {(-1.87 - 70*x)}}) Xinf = 1/(1 + {exp {(x + 0.075)/0.0055}}) setfield T03_H X_A->table[{i}] {Xtau} setfield T03_H X_B->table[{i}] {Xinf} x = x + dx end setfield T03_H X_A->calc_mode 1 setfield T03_H X_B->calc_mode 1 tweaktau T03_H X call T03_H TABFILL X 3000 0 /* KC-type calcium dependent potassium conductance*/ create tabchannel T03_KC setfield T03_KC Ek {EK} Gbar {GK} Ik 0 Gk 0 Xpower 1 Ypower 0 Zpower 1 call T03_KC TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} call T03_KC TABCREATE Z {tab_xdivs} {cai_min} {cai_max} x = {tab_xmin} cai = {cai_min} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) if ( x <= -0.010 ) XA = 0.053*{exp {((x + 0.05)/0.011) - ((x + 0.0535)/0.027)}} else XA = 2*{exp {(-x - 0.0535)/0.027}} end if ( x <= -0.010 ) XB = (2*{exp {(-x - 0.0535)/0.027}}) - {XA} else XB = 0 end if ( cai <= 250 ) Zinf = 0.004 * cai else Zinf = 1.0 end Xtau = 1.0e-3 / ({XA} + {XB}) Xinf = {XA} / ({XA} + {XB}) setfield T03_KC X_A->table[{i}] {Xtau} setfield T03_KC X_B->table[{i}] {Xinf} setfield T03_KC Z_A->table[{i}] {Zinf} setfield T03_KC Z_B->table[{i}] 1.0 x = x + dx cai = cai + dcai end setfield T03_KC X_A->calc_mode 1 setfield T03_KC X_B->calc_mode 1 setfield T03_KC Z_A->calc_mode 1 setfield T03_KC Z_B->calc_mode 1 setfield T03_KC instant {INSTANTZ} tweaktau T03_KC X call T03_KC TABFILL X 3000 0 call T03_KC TABFILL Z 3000 0 /* KM-type potassium conductance*/ create tabchannel T03_KM setfield T03_KM Ek {EK} Gbar {GK} Ik 0 Gk 0 Xpower 1 Ypower 0 Zpower 0 call T03_KM TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) XA = 0.02/(1 + {exp {(-x - 0.02)/0.005}}) XB = 0.01*{exp {(-x - 0.043)/0.018}} Xtau = 0.75e-3 / ({XA} + {XB}) Xinf = {XA} / ({XA} + {XB}) setfield T03_KM X_A->table[{i}] {Xtau} setfield T03_KM X_B->table[{i}] {Xinf} x = x + dx end setfield T03_KM X_A->calc_mode 1 setfield T03_KM X_B->calc_mode 1 tweaktau T03_KM X call T03_KM TABFILL X 3000 0 /*Afterhypolarizing calcium dependent potassium conductance*/ create tabchannel T03_KAHP setfield T03_KAHP Ek {EK} Gbar {GK} Ik 0 Gk 0 Xpower 0 Ypower 0 Zpower 1 call T03_KAHP TABCREATE Z {tab_xdivs} {cai_min} {cai_max} cai = {cai_min} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) if ( cai <= 100 ) ZA = 0.0001 * cai else ZA = 0.01 end ZB = 0.01 Ztau = 1.0e-3 / ({ZA} + {ZB}) Zinf = {ZA} / ({ZA} + {ZB}) setfield T03_KAHP Z_A->table[{i}] {Ztau} setfield T03_KAHP Z_B->table[{i}] {Zinf} cai = cai + dcai end setfield T03_KAHP Z_A->calc_mode 1 setfield T03_KAHP Z_B->calc_mode 1 tweaktau T03_KAHP Z call T03_KAHP TABFILL Z 3000 0 /* High threshold L-type calcium conductance*/ create tabchannel T03_CaL setfield T03_CaL Ek {ECa} Gbar {GCa} Ik 0 Gk 0 Xpower 1 Ypower 0 Zpower 0 call T03_CaL TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} x = {tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) XA = 1.6/(1 + {exp {-72*(x - 0.005)}}) XB = (0.02e3*(x + 0.0089))/({exp {(x + 0.0089)/0.005}} - 1) Xtau = 1.0e-3 / ({XA} + {XB}) Xinf = {XA} / ({XA} + {XB}) setfield T03_CaL X_A->table[{i}] {Xtau} setfield T03_CaL X_B->table[{i}] {Xinf} x = x + dx end setfield T03_CaL X_A->calc_mode 1 setfield T03_CaL X_B->calc_mode 1 tweaktau T03_CaL X call T03_CaL TABFILL X 3000 0 /* H-current channel based on Williams and Stuart (2000): Site independence of EPSP time course is mediated by dendritic Ih in neocortical pyramidal neurons. */ float tab_xmin = -0.1 float tab_xmax = 0.05 int tab_xdivs = 149 int i float x,dx,XA,XB,YA,YB,YAA,YAB dx = (1e3 * (tab_xmax-tab_xmin))/tab_xdivs //mV, tables are in V echo {dx} // only used for proto channels float G_WS_H = 1 float EH = -0.043 create tabchannel WS_H setfield WS_H Ek {EH} Gbar {G_WS_H} Ik 0 Gk 0 Xpower 1 Ypower 0 Zpower 0 call WS_H TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax} x = 1e3*{tab_xmin} for (i = 0 ; i <= {tab_xdivs} ; i = i + 1) XB = 1 / (1 + {exp {((-85.0 - x) / -6.1)}}) //tau defined below and above -82 mV if (x <= -71) XA = ({exp {(0.025 * x) + 6.68}}) / (1.0e3 * (Q10**{({t_sim}-34) / 10})) else XA = 5*({exp {(-0.027 * x) + 1.69}}) / (1.0e3 * (Q10**{({t_sim} - 34) / 10})) end setfield WS_H X_A->table[{i}] {XA} setfield WS_H X_B->table[{i}] {XB} x = x + dx end setfield WS_H X_A->calc_mode 1 setfield WS_H X_B->calc_mode 1 tweaktau WS_H X call WS_H TABFILL X 3000 0