// genesis
// 16Mar2005 The UCL (UK) discovered a bug in the code of the Ih channel,
// caused by inappropriate placement of the brackets in the argument of the exp function.
/*********************************************************************
** The current equations themselves
*********************************************************************/
/* First include Gran_chan_KCa.g for non-inactivating BK-type
** Ca-dependent K current.
*/
include Gran_chan_KCa.g
include Gran_chan_KA.g
float offset = 0.010
function make_Granule_chans
float temperature = 5
int i, cdivs
float zinf, ztau, c, dc, cmin, cmax
float x, dx, y
float a, b
/* The folowing variables are temporary (not temperature) variables
used to speed up computations */
float mintau
float tau
float temp1
float temp2
/* Equations specific to the Granule cell, made by CP */
/* Inactivating Na current */
create tabchannel Gran_InNa
setfield Gran_InNa Ek {ENa} Gbar 70 Ik 0 Gk 0 Xpower 3 Ypower 1 \
Zpower 0
call Gran_InNa TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
dx = ({tab_xmax} - {tab_xmin})/{tab_xdivs}
mintau = (1e-3*0.05)
temp1 = (1e3*1.5)
openfile InNa_a_max_37.test w
openfile InNa_a_tau_37.test w
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
temp2 = ((x) + 39e-3) // instead of ((x) + 39e-3)
a = (temp1)*({exp {0.081e3*(temp2)}})
b = (temp1)*({exp {-0.066e3*(temp2)}})
tau = 1/(a + b)
if (tau < (mintau)) // tau_min is 0.05*5e-3
setfield Gran_InNa X_A->table[{i}] {mintau / temperature}
else
setfield Gran_InNa X_A->table[{i}] {tau / temperature}
end
//Xinf
setfield Gran_InNa X_B->table[{i}] {a*tau}
writefile InNa_a_max_37.test {x} {getfield Gran_InNa X_B->table[{i}]}
writefile InNa_a_tau_37.test {x} {getfield Gran_InNa X_A->table[{i}]}
x = x + dx
end
tweaktau Gran_InNa X
setfield Gran_InNa X_A->calc_mode 1 X_B->calc_mode 1
closefile InNa_a_max_37.test
closefile InNa_a_tau_37.test
call Gran_InNa TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
mintau = (1e-3*0.225)
temp1 = (1e3*0.12)
openfile InNa_i_max_37.test w
openfile InNa_i_tau_37.test w
// trying to increase threshold
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
temp2 = (0.089e3)*(((x) + 50e-3)) // instead of (0.089e3)*(((x) + 50e-3))
a = (temp1)*({exp {-(temp2)}})
b = (temp1)*({exp {temp2}})
tau = 1/(a + b)
if (tau < mintau) // tau_min is 0.225*5e-3
setfield Gran_InNa Y_A->table[{i}] {mintau / temperature}
else
//Xinf
setfield Gran_InNa Y_A->table[{i}] {tau / temperature}
end
setfield Gran_InNa Y_B->table[{i}] {a*tau}
writefile InNa_i_max_37.test {x} {getfield Gran_InNa Y_B->table[{i}]}
writefile InNa_i_tau_37.test {x} {getfield Gran_InNa Y_A->table[{i}]}
x = x + dx
end
tweaktau Gran_InNa Y
setfield Gran_InNa Y_A->calc_mode 1 Y_B->calc_mode 1
closefile InNa_i_max_37.test
closefile InNa_i_tau_37.test
// Delayed Rectifier K current
create tabchannel Gran_KDr
setfield Gran_KDr Ek {EK} Gbar 19 Ik 0 Gk 0 Xpower 4 Ypower 1 \
Zpower 0
call Gran_KDr TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
dx = ({tab_xmax} - {tab_xmin})/{tab_xdivs}
temp1 = 1e3*0.17
openfile Kdr_a_max_37.test w
openfile Kdr_a_tau_37.test w
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
temp2 = x + 38e-3
a = temp1*({exp {0.073e3*(temp2)}})
b = temp1*({exp {-0.018e3*(temp2)}})
setfield Gran_KDr X_A->table[{i}] {temperature * a}
setfield Gran_KDr X_B->table[{i}] {temperature * (a + b)}
writefile Kdr_a_tau_37.test {x} {1 / (temperature * (a + b))}
writefile Kdr_a_max_37.test {x} {a / (a + b)}
x = x + dx
end
setfield Gran_KDr X_A->calc_mode 1 X_B->calc_mode 1
closefile Kdr_a_max_37.test
closefile Kdr_a_tau_37.test
call Gran_KDr TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
openfile Kdr_i_max_37.test w
openfile Kdr_i_tau_37.test w
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
if (x > -0.046)
a = 0.76
else a = 1e3*(0.0007 + 0.000065*({exp {-0.08e3*(x + 46e-3)}}))
end
b = 1e3*(110e-5)/(1 + ({exp {-0.0807e3*(x + 44e-3)}}))
setfield Gran_KDr Y_A->table[{i}] {temperature * a}
setfield Gran_KDr Y_B->table[{i}] {temperature * (a + b)}
writefile Kdr_i_tau_37.test {x} {1 / (temperature * (a + b))}
writefile Kdr_i_max_37.test {x} {a / (a + b)}
x = x + dx
end
setfield Gran_KDr Y_A->calc_mode 1 Y_B->calc_mode 1
closefile Kdr_i_tau_37.test
closefile Kdr_i_max_37.test
// K A-current fast transient potassium channel (see Gran_chan_KA.g)
make_Granule_KA
// High Voltage Activated HVA Ca current
create tabchannel Gran_CaHVA
setfield Gran_CaHVA Ek {ECa} Gbar 2.91 Ik 0 Gk 0 Xpower 2 \
Ypower 1 Zpower 0
call Gran_CaHVA TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
dx = ({tab_xmax} - {tab_xmin})/{tab_xdivs}
openfile CaHVA_a_max_37.test w
openfile CaHVA_a_tau_37.test w
// corrigenda Gabbiani et al. 1994, JNP february 1996
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
temp2 = x + 8.9e-3 // instead of x - 8.9e-3
a = 1e3*(1.6/(1 + ({exp {-0.072e3*(x - 5e-3)}})))
b = -(1e3*0.02e3*(temp2))/(1 - ({exp {0.2e3*(temp2)}}))
setfield Gran_CaHVA X_A->table[{i}] {temperature * a}
setfield Gran_CaHVA X_B->table[{i}] {temperature * (a + b)}
writefile CaHVA_a_tau_37.test {x} {1 / (temperature * (a + b))}
writefile CaHVA_a_max_37.test {x} {a / (a + b)}
x = x + dx
end
setfield Gran_CaHVA X_A->calc_mode 1 X_B->calc_mode 1
closefile CaHVA_a_max_37.test
closefile CaHVA_a_tau_37.test
call Gran_CaHVA TABCREATE Y {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
openfile CaHVA_i_max_37.test w
openfile CaHVA_i_tau_37.test w
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
if (x < -0.060)
a = 5.0
else a = 1e3*0.005*({exp {-0.05e3*(x + 60e-3)}})
end
if (x < -0.060)
b = 0.0
else b = (1e3*0.005) - (a)
end
setfield Gran_CaHVA Y_A->table[{i}] {temperature * a}
setfield Gran_CaHVA Y_B->table[{i}] {temperature * (a + b)}
writefile CaHVA_i_tau_37.test {x} {1 / (temperature * (a + b))}
writefile CaHVA_i_max_37.test {x} {a / (a + b)}
x = x + dx
end
setfield Gran_CaHVA Y_A->calc_mode 1 Y_B->calc_mode 1
closefile CaHVA_i_max_37.test
closefile CaHVA_i_tau_37.test
// Slowly relaxing, mixed Na/K current H
// Gabbiani et al. used this to model sag in membrane potential during
// hyperpolarizing current pulses
//
create tabchannel Gran_H
setfield Gran_H Ek {EH} Gbar 0.09 Ik 0 Gk 0 Xpower 1 Ypower 0 \
Zpower 0
call Gran_H TABCREATE X {tab_xdivs} {tab_xmin} {tab_xmax}
x = {tab_xmin} - {offset}
dx = ({tab_xmax} - {tab_xmin})/{tab_xdivs}
openfile H_a_max_37.test w
openfile H_a_tau_37.test w
for (i = 0; i <= ({tab_xdivs}); i = i + 1)
temp2 = 0.0909e3*(x + 75e-3)
a = 1e3*0.0008*({exp {-{temp2}}}) /* corrected 16 March 2005 */
b = 1e3*(0.0008*({exp {temp2}}))
setfield Gran_H X_A->table[{i}] {temperature * a}
setfield Gran_H X_B->table[{i}] {temperature * (a + b)}
writefile H_a_tau_37.test {x} {1 / (temperature * (a + b))}
writefile H_a_max_37.test {x} {a / (a + b)}
x = x + dx
end
setfield Gran_H X_A->calc_mode 1 X_B->calc_mode 1
closefile H_a_max_37.test
closefile H_a_tau_37.test
// non-inactivating BK-type Ca-dependent K current
// see Gran_chan_KCa.g
make_Moczyd_KC
end
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