//genesis
function make_KIR_channel
float Erev = -0.09 // V
str path = "KIR_channel"
float xmin = -0.15 /* minimum voltage we will see in the simulation */ // V
float xmax = 0.05 /* maximum voltage we will see in the simulation */ // V
int xdivsFiner = 4000
int c = 0
/****** Begin vars used to enable genesis calculations ********/
float increment = (xmax - xmin)*1e3/xdivsFiner // mV
echo "KIR increment:" {increment} "mV"
float x = -150.00
float minf = 0
float hinf = 0
float mvhalf = -52.0 // mV
float mshift = 50.0 // 30, mV
float mslope = 13.0 // mV
float taum = 0 // ms
float tauh = 0 // ms
/****** End vars used to enable genesis calculations **********/
create tabchannel {path}
call {path} TABCREATE X {xdivsFiner} {xmin} {xmax} // activation gate
// call {path} TABCREATE Y {xdivsFiner} {xmin} {xmax} // inactivation gate, no longer used
float qfactor = 0.5 // to match in vitro data, Wolf,et.al.2005
create table kir_taum // ms
call kir_taum TABCREATE 20 {xmin} {xmax}
//the table corresponds to -150 mV to 50 mV, digitally extracted from JE Steephen,et.al. 2008, fig1
setfield kir_taum table->table[0] 0.2 \
table->table[1] 0.2 \
table->table[2] 0.2 \
table->table[3] 0.2 \
table->table[4] 0.2 \
table->table[5] 0.38 \
table->table[6] 0.97 \
table->table[7] 1.486 \
table->table[8] 5.3763 \
table->table[9] 6.0606 \
table->table[10] 6.8966 \
table->table[11] 7.6923 \
table->table[12] 7.1429 \
table->table[13] 5.8824 \
table->table[14] 4.4444 \
table->table[15] 4.0 \
table->table[16] 4.0 \
table->table[17] 4.0 \
table->table[18] 4.0 \
table->table[19] 4.0 \
table->table[20] 4.0
call kir_taum TABFILL {xdivsFiner} 2
// table for hinf
// In Steephen's paper, there are only three hinf values, corresponding to -120,-90 and -50 mV.
// to expand table from -150 mV to +50 mV, I set hinf(<-120mV) = hinf(-120mV), hinf(-50 mV) = hinf(>-50mV)
/* We might not need inactivation gate now
create table kir_hinf
call kir_hinf TABCREATE 20 {xmin} {xmax}
setfield kir_hinf table->table[0] 0.53 \
table->table[1] 0.53 \
table->table[2] 0.53 \
table->table[3] 0.53 \
table->table[4] 0.55 \
table->table[5] 0.57 \
table->table[6] 0.59 \
table->table[7] 0.6925 \
table->table[8] 0.7950 \
table->table[9] 0.8975 \
table->table[10] 1.0 \
table->table[11] 1.0 \
table->table[12] 1.0 \
table->table[13] 1.0 \
table->table[14] 1.0 \
table->table[15] 1.0 \
table->table[16] 1.0 \
table->table[17] 1.0 \
table->table[18] 1.0 \
table->table[19] 1.0 \
table->table[20] 1.0
call kir_hinf TABFILL {xdivsFiner} 2
//table for tauh
create table kir_tauh
call kir_tauh TABCREATE 20 {xmin} {xmax}
setfield kir_tauh table->table[0] 7.8 \
table->table[1] 7.8 \
table->table[2] 7.8 \
table->table[3] 7.8 \
table->table[4] 10.2 \
table->table[5] 12.6 \
table->table[6] 15.0 \
table->table[7] 17.575 \
table->table[8] 20.15 \
table->table[9] 22.725 \
table->table[10] 25.3 \
table->table[11] 25.3 \
table->table[12] 25.3 \
table->table[13] 25.3 \
table->table[14] 25.3 \
table->table[15] 25.3 \
table->table[16] 25.3 \
table->table[17] 25.3 \
table->table[18] 25.3 \
table->table[19] 25.3 \
table->table[20] 25.3
call kir_tauh TABFILL {xdivsFiner} 2
*/
/*fills the tabchannel with values for KIR_alpha & KIR_beta*/
for(c = 0; c < {xdivsFiner} + 1; c = c + 1)
minf = 1/(1 + {exp {(x - mvhalf + mshift)/mslope}})
// hinf = {getfield kir_hinf table->table[{c}]}
taum = {getfield kir_taum table->table[{c}]}/qfactor
// tauh = {getfield kir_tauh table->table[{c}]}
setfield {path} X_A->table[{c}] {taum*1e-3}
setfield {path} X_B->table[{c}] {minf}
// setfield {path} Y_A->table[{c}] {tauh*1e-3}
// setfield {path} Y_B->table[{c}] {hinf}
x = x + increment
end
/* Defines the powers of m Hodgkin-Huxley equation*/
setfield {path} Ek {Erev} Xpower 1 Ypower 0
/* fill the tables with the values of tau and minf/hinf
* calculated from tau and minf/hinf
*/
tweaktau {path} X
// tweaktau {path} Y
end
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