ASTchan.g.txt
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// genesis
/* FILE INFORMATION - last update: Aug 17, 1993
** Molluscan Voltage dependent Na, K, KA, Ca, slow Na/Ca channels
** The channels given below are representative of those found in
** molluscan soma described in the review paper by
** David J. Adams, Stephen J. Smith and Stuart H. Thompson
** (Ann. Rev. Neurosci. 3, p.141 (1980)) and in other references below.
** Implemented by David Beeman - January 1991
** Converted to tabchans by Upinder S. Bhalla - Feb 1991
** Further additions and corrections by D. Beeman - Oct 92, Jan 93, Aug 93
** Converted to GENESIS 2 - March 1995
** All parameters are in SI (MKSA) units.
** The nominal resting membrane potential is -0.040 V.
**
**
** Typical equilibrium potentials taken from these references are:
** ENa = 0.050
** EK = -0.060
** EA = -0.063
** ECa = 0.064
** EB = 0.068 // +/- 0.059 V uncertainty!
**
** This file depends on functions and constants defined in defaults.g
*/
// CONSTANTS
float ENa = 0.050
float EK = -0.060
float EA = -0.063
float ECa = 0.064
float EB = 0.068 // +/- 0.059 V uncertainty!
float SOMA_A = 2e-7 // sq m
/***********************************************************************
Na-Current
Adams and Gage, J. Physiol. 289, p. 143 (1979) (Aplysia R15)
***********************************************************************/
/* The activation curve (X gate) has been shifted down by -5 mV to make it
more like the Connor and Stevens I-current and provide more robust firing
when used with the Late potassium K-Current in this file. In order to
restore it to the curve measured by Adams and Gage, add the command
"scale_tabchan Na_aplysia_ag X minf 1.0 1.0 0.005 0.0" to the end of this
function.
*/
function make_Na_aplysia_ag // Na-current
str chanpath = "Na_aplysia_ag"
if ({exists {chanpath}})
return
end
create tabchannel {chanpath}
setfield {chanpath} \
Ek {ENa} \
Gbar {137.5 * SOMA_A} \
Ik 0 \
Gk 0 \
Xpower 3 \
Ypower 1 \
Zpower 0
call {chanpath} TABCREATE X 30 -0.100 0.050
setfield {chanpath} \ // A = tau_m, B = m_inf
X_A->table[0] 0.0122 X_B->table[0] 0.0 \ // -0.1
X_A->table[1] 0.0122 X_B->table[1] 0.0 \
X_A->table[2] 0.0122 X_B->table[2] 0.0 \ // -0.09
X_A->table[3] 0.0122 X_B->table[3] 0.0 \
X_A->table[4] 0.0122 X_B->table[4] 0.0 \ // -0.08
X_A->table[5] 0.0122 X_B->table[5] 0.0 \
X_A->table[6] 0.0122 X_B->table[6] 0.0 \ // -0.07
X_A->table[7] 0.0122 X_B->table[7] 0.0 \
X_A->table[8] 0.0122 X_B->table[8] 0.0 \ // -0.06
X_A->table[9] 0.0122 X_B->table[9] 0.0 \
X_A->table[10] 0.0122 X_B->table[10] 0.0 \ // -0.05
X_A->table[11] 0.0122 X_B->table[11] 0.0 \
X_A->table[12] 0.0122 X_B->table[12] 0.0 \ // -0.04
X_A->table[13] 0.0122 X_B->table[13] 0.0494 \
X_A->table[14] 0.0116 X_B->table[14] 0.2414 \ // -0.030
X_A->table[15] 0.00938 X_B->table[15] 0.4077 \
X_A->table[16] 0.00762 X_B->table[16] 0.5817 \ // -0.020
X_A->table[17] 0.00586 X_B->table[17] 0.7768 \
X_A->table[18] 0.00376 X_B->table[18] 0.9069 \ // -0.010
X_A->table[19] 0.00228 X_B->table[19] 0.9626 \
X_A->table[20] 0.00158 X_B->table[20] 0.9843 \ // 0.00
X_A->table[21] 0.00122 X_B->table[21] 0.9940 \
X_A->table[22] 0.00097 X_B->table[22] 0.9992 \ // 0.010
X_A->table[23] 0.00078 X_B->table[23] 1.0000 \
X_A->table[24] 0.00067 X_B->table[24] 1.0000 \ // 0.020
X_A->table[25] 0.00054 X_B->table[25] 1.0000 \
X_A->table[26] 0.00050 X_B->table[26] 1.0000 \ // 0.030
X_A->table[27] 0.00048 X_B->table[27] 1.0000 \
X_A->table[28] 0.00047 X_B->table[28] 1.0000 \ // 0.040
X_A->table[29] 0.00047 X_B->table[29] 1.0000 \
X_A->table[30] 0.00047 X_B->table[30] 1.0000 // 0.050
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} X_A->calc_mode 0 X_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweaktau {chanpath} X
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL X 3000 0
call {chanpath} TABCREATE Y 30 -0.100 0.050
setfield {chanpath} \ // A = tau_h, B = h_inf
Y_A->table[0] 0.065 Y_B->table[0] 1.0 \ // -0.1
Y_A->table[1] 0.065 Y_B->table[1] 1.0 \
Y_A->table[2] 0.065 Y_B->table[2] 1.0 \ // -0.09
Y_A->table[3] 0.065 Y_B->table[3] 1.0 \
Y_A->table[4] 0.065 Y_B->table[4] 1.0 \ // -0.08
Y_A->table[5] 0.065 Y_B->table[5] 1.0 \
Y_A->table[6] 0.065 Y_B->table[6] 1.0 \ // -0.07
Y_A->table[7] 0.065 Y_B->table[7] 1.0 \
Y_A->table[8] 0.065 Y_B->table[8] 1.0 \ // -0.06
Y_A->table[9] 0.065 Y_B->table[9] 1.0 \
Y_A->table[10] 0.065 Y_B->table[10] 0.998 \ // -0.05
Y_A->table[11] 0.0575 Y_B->table[11] 0.987 \
Y_A->table[12] 0.050 Y_B->table[12] 0.935 \ // -0.04
Y_A->table[13] 0.044 Y_B->table[13] 0.731 \
Y_A->table[14] 0.038 Y_B->table[14] 0.339 \ // -0.030
Y_A->table[15] 0.032 Y_B->table[15] 0.0884 \
Y_A->table[16] 0.027 Y_B->table[16] 0.0180 \ // -0.020
Y_A->table[17] 0.0232 Y_B->table[17] 0.0034 \
Y_A->table[18] 0.0209 Y_B->table[18] 0.0 \ // -0.010
Y_A->table[19] 0.0185 Y_B->table[19] 0.0 \
Y_A->table[20] 0.0168 Y_B->table[20] 0.0 \ // 0.00
Y_A->table[21] 0.0153 Y_B->table[21] 0.0 \
Y_A->table[22] 0.0135 Y_B->table[22] 0.0 \ // 0.010
Y_A->table[23] 0.0129 Y_B->table[23] 0.0 \
Y_A->table[24] 0.0118 Y_B->table[24] 0.0 \ // 0.020
Y_A->table[25] 0.0111 Y_B->table[25] 0.0 \
Y_A->table[26] 0.0103 Y_B->table[26] 0.0 \ // 0.030
Y_A->table[27] 0.0100 Y_B->table[27] 0.0 \
Y_A->table[28] 0.0096 Y_B->table[28] 0.0 \ // 0.040
Y_A->table[29] 0.0094 Y_B->table[29] 0.0 \
Y_A->table[30] 0.0088 Y_B->table[30] 0.0 // 0.050
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} Y_A->calc_mode 0 Y_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweaktau {chanpath} Y
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL Y 3000 0
end
/**********************************************************************
** Late potassium K-Current
** K current activation from Thompson, J. Physiol 265: 465 (1977)
** (Tritonia (LPl 2 and LPl 3 cells)
** Inactivation from RW Aldrich, PA Getting, and SH Thompson,
** J. Physiol, 291: 507 (1979) (Anisidoris and Archidoris)
**
**********************************************************************/
function make_K_trit_agt // K-current
str chanpath = "K_trit_agt"
if ({exists {chanpath}})
return
end
create tabchannel {chanpath}
setfield {chanpath} \
Ek {EK} \
Gbar {65.7 * SOMA_A} \
Ik 0 \
Gk 0 \
Xpower 2 \
Ypower 1 \
Zpower 0
call {chanpath} TABCREATE X 30 -0.100 0.050
settab2const {chanpath} X_A 0 12 0.0 //-0.1 thru -0.045=>0.0
setfield {chanpath} \
X_A->table[13] 0.00 \
X_A->table[14] 2.87 \ // -0.030
X_A->table[15] 4.68 \
X_A->table[16] 7.46 \ // -0.020
X_A->table[17] 10.07 \
X_A->table[18] 14.27 \ // -0.010
X_A->table[19] 17.87 \
X_A->table[20] 22.9 \ // 0.0
X_A->table[21] 33.6 \
X_A->table[22] 49.3 \ // 0.010
X_A->table[23] 65.6 \
X_A->table[24] 82.0 \ // 0.020
X_A->table[25] 110.0 \
X_A->table[26] 147.1 \ // 0.030
X_A->table[27] 147.1 \
X_A->table[28] 147.1 \ // 0.040
X_A->table[29] 147.1 \
X_A->table[30] 147.1 // 0.050
settab2const {chanpath} X_B 0 11 16.6 //-0.1 thru -0.045=>16.6
setfield {chanpath} \
X_B->table[12] 16.6 \ // -0.040 Volts
X_B->table[13] 15.4 \
X_B->table[14] 13.5 \ // -0.030
X_B->table[15] 13.2 \
X_B->table[16] 11.9 \ // -0.020
X_B->table[17] 11.5 \
X_B->table[18] 10.75 \ // -0.010
X_B->table[19] 9.30 \
X_B->table[20] 8.30 \ // 0.00
X_B->table[21] 6.00 \
X_B->table[22] 5.10 \ // 0.010
X_B->table[23] 4.80 \
X_B->table[24] 3.20 \ // 0.020
X_B->table[25] 1.60 \
X_B->table[26] 0.00 \ // 0.030
X_B->table[27] 0.00 \
X_B->table[28] 0.00 \ // 0.040
X_B->table[29] 0.00 \
X_B->table[30] 0.00 // 0.050
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} X_A->calc_mode 0 X_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweakalpha {chanpath} X
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL X 3000 0
/* The alpha and beta values used here for the inactivation correspond to
a constant value of tau_h = 1 sec. This is a simplification of the
AG&T results. The "burster" tutorial sets Ypower to 0 (no inactivation).
*/
call {chanpath} TABCREATE Y 30 -0.100 0.050
settab2const {chanpath} Y_A 0 11 1.0 //-0.1 thru -0.035 => 1.0
setfield {chanpath} \
Y_A->table[12] 1.00 \ // -0.040 Volts
Y_A->table[13] 0.97 \ //
Y_A->table[14] 0.94 \ // -0.030 Volts
Y_A->table[15] 0.88 \
Y_A->table[16] 0.75 \ // -0.020
Y_A->table[17] 0.61 \
Y_A->table[18] 0.43 \ // -0.010
Y_A->table[19] 0.305 \
Y_A->table[20] 0.220 \ // 0.00
Y_A->table[21] 0.175 \
Y_A->table[22] 0.155 \ // 0.010
Y_A->table[23] 0.143 \
Y_A->table[24] 0.138 \ // 0.020
Y_A->table[25] 0.137 \
Y_A->table[26] 0.136 \ // 0.030
Y_A->table[27] 0.135 \
Y_A->table[28] 0.135 \ // 0.040
Y_A->table[29] 0.135 \
Y_A->table[30] 0.135 // 0.050
settab2const {chanpath} Y_B 0 11 0.0 //-0.1 thru -0.045 => 0.0
setfield {chanpath} \
Y_B->table[12] 0.0 \ // -0.040 Volts
Y_B->table[13] 0.03 \ //
Y_B->table[14] 0.06 \ // -0.030 Volts
Y_B->table[15] 0.12 \
Y_B->table[16] 0.25 \ // -0.020
Y_B->table[17] 0.39 \
Y_B->table[18] 0.57 \ // -0.010
Y_B->table[19] 0.695 \
Y_B->table[20] 0.78 \ // 0.00
Y_B->table[21] 0.825 \
Y_B->table[22] 0.845 \ // 0.010
Y_B->table[23] 0.857 \
Y_B->table[24] 0.862 \ // 0.020
Y_B->table[25] 0.863 \
Y_B->table[26] 0.864 \ // 0.030
Y_B->table[27] 0.865 \
Y_B->table[28] 0.865 \ // 0.040
Y_B->table[29] 0.865 \
Y_B->table[30] 0.865 // 0.050
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} Y_A->calc_mode 0 Y_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweakalpha {chanpath} Y
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL Y 3000 0
end
/**********************************************************************
** Transient potassium A-Current
** J. A. Connor and C. F. Stevens, J. Physiol. (1971) 213, p. 31
** data for Anisidoris gastropod neurons
**********************************************************************/
function make_KA_moll_cs // A-current
str chanpath = "A_moll_cs"
if ({exists {chanpath}})
return
end
create tabchannel {chanpath}
setfield {chanpath} \
Ek {EA} \
Gbar {65.7 * SOMA_A} \
Ik 0 \
Gk 0 \
Xpower 4 \
Ypower 1 \
Zpower 0
call {chanpath} TABCREATE X 30 -0.100 0.050
settab2const {chanpath} X_A 0 7 0.0 //-0.1 thru -0.065 => 0.0
setfield {chanpath} \
X_A->table[8] 0.1 \ // -0.060 Volts
X_A->table[9] 20.8 \
X_A->table[10] 38.4 \ // -0.050
X_A->table[11] 47.2 \
X_A->table[12] 54.3 \ // -0.040
X_A->table[13] 60.8 \
X_A->table[14] 65.7 \ // -0.030
X_A->table[15] 71.0 \
X_A->table[16] 74.8 \ // -0.020
X_A->table[17] 78.0 \ // a guess!
X_A->table[18] 80.0 \ // -0.010
X_A->table[19] 83.0
settab2const {chanpath} X_A 20 30 83.3 //0 thru 50 => 83.3
settab2const {chanpath} X_B 0 7 83.3 //-0.1 thru -0.065 => 83.3
setfield {chanpath} \
X_B->table[8] 83.3 \ // -0.060 Volts
X_B->table[9] 62.6 \
X_B->table[10] 44.9 \ // -0.050
X_B->table[11] 36.2 \
X_B->table[12] 29.1 \ // -0.040
X_B->table[13] 22.6 \
X_B->table[14] 17.7 \ // -0.030
X_B->table[15] 12.3 \
X_B->table[16] 8.5 \ // -0.020
X_B->table[17] 5.0 \ // a guess!
X_B->table[18] 3.1 \ // -0.010
X_B->table[19] 1.2
settab2const {chanpath} X_B 20 30 0.0 //0 thru 0.050 => 0.0
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} X_A->calc_mode 0 X_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweakalpha {chanpath} X
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL X 3000 0
call {chanpath} TABCREATE Y 30 -0.100 0.050
setfield {chanpath} \
Y_A->table[0] 4.26 \ // -0.100 Volts
Y_A->table[1] 4.12 \
Y_A->table[2] 3.95 \ // -0.090
Y_A->table[3] 3.69 \
Y_A->table[4] 3.34 \ // -0.080
Y_A->table[5] 2.94 \
Y_A->table[6] 2.32 \ // -0.070
Y_A->table[7] 1.54 \
Y_A->table[8] 0.66 \ // -0.060
Y_A->table[9] 0.306 \
Y_A->table[10] 0.123 \ // -0.050
Y_A->table[11] 0.053
settab2const {chanpath} Y_A 12 30 0.0 // -0.04 thru 0.05 => 0.0
setfield {chanpath} \
Y_B->table[0] 0.00 \ // -0.1 Volts
Y_B->table[1] 0.13 \
Y_B->table[2] 0.31 \ // -0.090
Y_B->table[3] 0.57 \
Y_B->table[4] 0.92 \ // -0.080
Y_B->table[5] 1.32 \
Y_B->table[6] 1.93 \ // -0.070
Y_B->table[7] 2.72 \
Y_B->table[8] 3.60 \ // -0.060 mV
Y_B->table[9] 3.95 \
Y_B->table[10] 4.13 \ // -0.050 mV
Y_B->table[11] 4.20
settab2const {chanpath} Y_B 12 30 4.26 // -0.04 thru 0.05=> 4.26
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} Y_A->calc_mode 0 Y_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweakalpha {chanpath} Y
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL Y 3000 0
end
/**********************************************************************
** High threshold Ca-current
** Adams and Gage, J. Physiol 289 p143 (1979) (Aplysia R15)
**********************************************************************/
function make_Ca_aplysia_ag // Ca-current
str chanpath = "Ca_aplysia_ag"
if ({exists {chanpath}})
return
end
create tabchannel {chanpath}
setfield {chanpath} \
Ek {ECa} \
Gbar {65.2 * SOMA_A} \
Ik 0 \
Gk 0 \
Xpower 2 \
Ypower 1 \
Zpower 0
call {chanpath} TABCREATE X 30 -0.100 0.050
settab2const {chanpath} X_A 0 18 0.0 //-0.1 thru -0.005 => 0.0
setfield {chanpath} \
X_A->table[19] 0.0 \ // -0.005 Volts
X_A->table[20] 39.2 \ // 0.0
X_A->table[21] 46.7 \ // 0.005
X_A->table[22] 54.2 \ // 0.010
X_A->table[23] 85.3 \ // 0.015
X_A->table[24] 111.9 \ // 0.020
X_A->table[25] 128.2 \ // 0.025
X_A->table[26] 144.6 \ // 0.030
X_A->table[27] 156.7 \ // 0.035
X_A->table[28] 166.7 \ // 0.040
X_A->table[29] 166.7 \ // 0.045
X_A->table[30] 166.7 // 0.050
settab2const {chanpath} X_B 0 17 250.0 //-0.1 thru -0.01 =>250
setfield {chanpath} \
X_B->table[18] 250.0 \ // -0.010 Volts
X_B->table[19] 217.0 \ // -0.005 Volts
X_B->table[20] 147.0 \ // 0.0
X_B->table[21] 103.9 \ // 0.005
X_B->table[22] 64.4 \ // 0.010
X_B->table[23] 26.5 \ // 0.015
X_B->table[24] 8.55 \ // 0.020
X_B->table[25] 2.35 \ // 0.025
X_B->table[26] 0.58 \ // 0.030
X_B->table[27] 0.0 \ // 0.035
X_B->table[28] 0.0 \ // 0.040
X_B->table[29] 0.0 \ // 0.045
X_B->table[30] 0.0 // 0.050
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} X_A->calc_mode 0 X_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweakalpha {chanpath} X
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL X 3000 0
call {chanpath} TABCREATE Y 30 -0.100 0.050
settab2const {chanpath} Y_A 0 11 10.0 // -0.1 to -0.04=>10.0
setfield {chanpath} \
Y_A->table[12] 10.0 \ // -0.040 Volts
Y_A->table[13] 9.7 \
Y_A->table[14] 9.24 \ // -0.030
Y_A->table[15] 7.5 \
Y_A->table[16] 5.0 \ // -0.020
Y_A->table[17] 2.5 \
Y_A->table[18] 0.633 \ // -0.010
Y_A->table[19] 0.153 \
Y_A->table[20] 0.004 \ // 0.00
Y_A->table[21] 0.0
settab2const {chanpath} Y_A 22 30 0.0 // 0.01 thru 0.05 => 0.0
settab2const {chanpath} Y_B 0 11 0.0 // -0.1 to -0.04=>00.0
setfield {chanpath} \
Y_B->table[12] 0.0 \ // -0.040 Volts
Y_B->table[13] 0.3 \
Y_B->table[14] 0.76 \ // -0.030
Y_B->table[15] 2.5 \
Y_B->table[16] 5.0 \ // -0.020
Y_B->table[17] 6.5 \
Y_B->table[18] 7.7 \ // -0.010
Y_B->table[19] 6.51 \
Y_B->table[20] 5.68 \ // 0.00
Y_B->table[21] 4.44 \
Y_B->table[22] 3.85 \ // 0.010
Y_B->table[23] 5.26 \
Y_B->table[24] 8.33 \ // 0.020
Y_B->table[25] 11.11 \
Y_B->table[26] 14.29 \ // 0.030
Y_B->table[27] 16.67 \
Y_B->table[28] 18.18 \ // 0.040
Y_B->table[29] 18.18 \
Y_B->table[30] 18.18 //0.05
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} Y_A->calc_mode 0 Y_B->calc_mode 0
/* tweaking the tables for the tabchan calculation */
tweakalpha {chanpath} Y
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL Y 3000 0
end
/**********************************************************************
** B-current : Slow inward Na and Ca bursting conductance
** SJ Smith and SH Thompson J.Physiol 382 p425 (1987) (Tritonia)
**********************************************************************/
function make_B_trit_st
str chanpath = "B_trit_st"
if ({exists {chanpath}})
return
end
create tabchannel {chanpath}
setfield {chanpath} \
Ek {EB} \
Gbar {0.35*SOMA_A} \
Ik 0 \
Gk 0 \
Xpower 1 \
Ypower 0 \
Zpower 0
call {chanpath} TABCREATE X 30 -0.100 0.050 // in volts
settab2const {chanpath} X_A 0 7 2.270
setfield {chanpath} X_A->table[8] 2.270 \ // -60 mV
X_A->table[9] 2.040 \ // -55 mV
X_A->table[10] 1.800 \ // -50 mV
X_A->table[11] 1.513 \ // -45 mV
X_A->table[12] 1.220 \ // -40 mV
X_A->table[13] 0.957 \ // -35 mV
X_A->table[14] 0.690 \ // -30 mV
X_A->table[15] 0.515 \ // -25 mV
X_A->table[16] 0.390 \ // -20 mV
X_A->table[17] 0.337 \ // -15 mV
X_A->table[18] 0.310 \ // -10 mV
X_A->table[19] 0.271 \ // -5 mV
X_A->table[20] 0.240 \ // 0 mV
X_A->table[21] 0.216 \ // 5 mV
X_A->table[22] 0.209 \ // 10 mV
X_A->table[23] 0.205 \ // 15 mV
X_A->table[24] 0.202 \ // 20 mV
X_A->table[25] 0.191 \ // 25 mV
X_A->table[26] 0.174 \ // 30 mV
X_A->table[27] 0.157 \ // 35 mV
X_A->table[28] 0.139 \ // 40 mV
X_A->table[29] 0.115 \ // 45 mV
X_A->table[30] 0.104 // 50 mV
settab2const {chanpath} X_B 0 8 0.0
setfield {chanpath} X_B->table[9] 0.0 \ // -55 mV
X_B->table[10] 0.011 \ // -50 mV
X_B->table[11] 0.0224\ // -45 mV
X_B->table[12] 0.0370\ // -40 mV
X_B->table[13] 0.0555\ // -35 mV
X_B->table[14] 0.0815\ // -30 mV
X_B->table[15] 0.1111\ // -25 mV
X_B->table[16] 0.1333\ // -20 mV
X_B->table[17] 0.155 \ // -15 mV
X_B->table[18] 0.181 \ // -10 mV
X_B->table[19] 0.200 \ // -5 mV
X_B->table[20] 0.222 \ // 0 mV
X_B->table[21] 0.244 \ // 5 mV
X_B->table[22] 0.270 \ // 10 mV
X_B->table[23] 0.296 \ // 15 mV
X_B->table[24] 0.322 \ // 20 mV
X_B->table[25] 0.357 \ // 25 mV
X_B->table[26] 0.400 \ // 30 mV
X_B->table[27] 0.456 \ // 35 mV
X_B->table[28] 0.504 \ // 40 mV
X_B->table[29] 0.550 \ // 45 mV
X_B->table[30] 0.585 // 50 mV
/* tweaking the tables for the tabchan calculation */
tweaktau {chanpath} X
/* Filling the tables using B-SPLINE interpolation */
call {chanpath} TABFILL X 3000 0
/* Setting the calc_mode to NO_INTERP for speed */
setfield {chanpath} X_A->calc_mode 0 X_B->calc_mode 0
end
//========================================================================
// Ca concentration (from Ca and B channels)
//========================================================================
// Cell reader will set up messages from Ca_aplysia_ag and from B_trit_st
// If these channel names are changed in the channel creation functions,
// change them in the messages here also
function make_Ca_conc
if ({exists Ca_conc})
return
end
create Ca_concen Ca_conc
setfield Ca_conc \
tau 17.5 \ // sec
B 1000 \ // Curr to conc for soma
Ca_base 0
addfield Ca_conc addmsg1
addfield Ca_conc addmsg2
setfield Ca_conc \
addmsg1 "../Ca_aplysia_ag . I_Ca Ik" \
addmsg2 "../B_trit_st . I_Ca Ik"
end
//========================================================================
// Ca-dependent K Channel - K(C) - (vdep_channel with table and tabgate)
// Voltage and [Ca] dependence was taken from A. L. F. Gorman and M. V.
// Thomas, J. Physiol. (London) 308: 287-313 (1980). (Aplysia R15)
//========================================================================
function make_Kc_aplysia_gt
str chanpath = "K_C"
if ({exists {chanpath}})
return
end
create vdep_channel {chanpath}
setfield ^ \
Ek {EK} \ // V
gbar { 124.0 * SOMA_A } \ // S
Ik 0 \ // A
Gk 0 // S
// Create a table for the function of concentration, allowing a
// concentration range of 0 to 2000e-6, with 50 divisions. Note that the
// internal field for the table object is called "table".
float xmin = 0.0
float xmax = 0.002
int xdivs = 50
float Ca_max = 187e-6 // nominal conc for expt results = 187 nM
create table {chanpath}/tab
call {chanpath}/tab TABCREATE {xdivs} {xmin} {xmax}
int i
float x,dx,y
dx = (xmax - xmin)/xdivs
x = xmin
// The concentration-dependent factor is a linear function of [Ca]
// which is unity at [Ca] = Ca_max
for (i = 0 ; i <= {xdivs} ; i = i + 1)
y = x/Ca_max
setfield {chanpath}/tab table->table[{i}] {y}
x = x + dx
end
// Expand the table to 3000 entries to use without interpolation. The
// TABFILL syntax is slightly different from that used with tabchannels.
// Here there is only one internal table, so the table name is not specified.
setfield {chanpath}/tab table->calc_mode 0
call {chanpath}/tab TABFILL 3000 0
// Now make a tabgate for the voltage-dependent activation parameter.
float xmin = -0.1
float xmax = 0.05
int xdivs = 49
create tabgate {chanpath}/X
call {chanpath}/X TABCREATE alpha {xdivs} {xmin} {xmax}
call {chanpath}/X TABCREATE beta {xdivs} {xmin} {xmax}
int i
float x,dx,alpha,beta, minf, tau
tau = 3.8 // estimate from Thompson, Smith and Johnson 1986
dx = (xmax - xmin)/xdivs
x = xmin
for (i = 0 ; i <= {xdivs} ; i = i + 1)
minf = 1/(1.0 + {exp {(0.0653 - x)/0.0253}})
alpha = minf/tau
beta = (1-minf)/tau
setfield {chanpath}/X alpha->table[{i}] {alpha}
setfield {chanpath}/X beta->table[{i}] {beta}
x = x + dx
end
setfield {chanpath}/X alpha->calc_mode 0 beta->calc_mode 0
call {chanpath}/X TABFILL alpha 3000 0
call {chanpath}/X TABFILL beta 3000 0
addmsg {chanpath}/tab {chanpath} MULTGATE output 1
addmsg {chanpath}/X {chanpath} MULTGATE m 1
addfield {chanpath} addmsg1
addfield {chanpath} addmsg2
setfield {chanpath} \
addmsg1 "../Ca_conc tab INPUT Ca" \
addmsg2 ".. X VOLTAGE Vm"
end
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