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%
% Victor V. Matveev, Richard Bertram and Arthur Sherman (2011)
% Ca2+ Cooperativity of Exocytosis as a Measure of Ca2+ Channel Domain Overlap.
% Brain Research 1398: 126-138.
%
% This CalC simulation script reproduces Fig. 4B of the manuscript
% Victor Matveev, January 8, 2011
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verbose = 0
file = "equi_M5_Imax" Imax "pA_Dist" 1000*Dist "nm_" N "x" M ".dat"
tfile = file ".temp"
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Imax = 0.05
Dist = 0.03
volume 0 L 0 L 0 L
L = 1
MID = L / 2
N = 70
M = 50
grid N N M
s1 = MID - Dist
s2 = MID + Dist
stretch x s1 s2
stretch y s1 s2
stretch z 0 0
stretch.factor = 1.05
a1 = 0
a2 = 2*pi/5
a3 = 4*pi/5
a4 = 6*pi/5
a5 = 8*pi/5
x1 = MID + Dist * cos(a1); y1 = MID + Dist * sin(a1);
x2 = MID + Dist * cos(a2); y2 = MID + Dist * sin(a2);
x3 = MID + Dist * cos(a3); y3 = MID + Dist * sin(a3);
x4 = MID + Dist * cos(a4); y4 = MID + Dist * sin(a4);
x5 = MID + Dist * cos(a5); y5 = MID + Dist * sin(a5);
Ca.source x1 y1 0 ww ww ww
Ca.source x2 y2 0 ww ww ww
Ca.source x3 y3 0 ww ww ww
Ca.source x4 y4 0 ww ww ww
Ca.source x5 y5 0 ww ww ww
ww = 0.004
Ca.D = 0.2
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
T0 = 1; T1 = 1; T2 = 4
Run adaptive T0
currents 0 0 0 0 0
Run adaptive T1
currents I1 I2 I3 I4 I5
Run adaptive T2
currents 0 0 0 0 0
I = Imax pA
I1 = I ff{5}
I2 = I ff{4}
I3 = I ff{3}
I4 = I ff{2}
I5 = I ff{1}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
buffer B
B.D = 0.05
B.KD = 1
B.kplus = 0.65
uptake = 0.004
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Felmy-Neher-Schenggenburger Ca-binding scheme (Neuron 37:801, 2003)
X(0)=9.965526822168e-01;
X1(0)=3.428235798835e-03;
X2(0)=1.886953032458e-05;
X3(0)=2.077213841252e-07;
X4(0)=4.572912343658e-09
Ca.bgr=0.05
C := Ca[MID,MID,0]
dX/dt = - 5 C kon X + koff X1
dX1/dt = 5 kon C X - koff X1 - 4 C kon X1 + 2 koff b X2
dX2/dt = 4 kon C X1 - 2 koff b X2 - 3 C kon X2 + 3 koff b^2 X3
dX3/dt = 3 kon C X2 - 3 koff b^2 X3 - 2 C kon X3 + 4 koff b^3 X4
dX4/dt = 2 kon C X3 - 4 koff b^3 X4 - C kon X4 + 5 koff b^4 X5
X5 := 1 - X - X1 - X2 - X3 - X4
R := gamma X5
kon = 0.116
koff = 8.430
gamma = 6.96
b = 0.25
TM = T0 + T1 + T2
Tmax Rmax max R 0 TM
Cmax max C 0 TM
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
lB0 = log(10)
lB1 = log(10000)
dlB = (lB1 - lB0) / 20
for lB = lB0 to lB1 step dlB
B.total = exp(lB)
parStr = B.total
for iter = 1 to 7 step 1
if iter == 1 then
ff = 1 0 0 0 0
print tfile "start; "
if lB == lB0 then
print file parStr
endif
endif
if iter == 2 then
ff = 1 1 0 0 0
endif
if iter == 3 then
ff = 1 0 1 0 0
endif
if iter == 4 then
ff = 1 1 1 0 0
endif
if iter == 5 then
ff = 1 1 0 1 0
endif
if iter == 6 then
ff = 1 1 1 1 0
endif
if iter >=1 and iter < 7 then
append tfile "; Rmax" iter " = " Rmax "; Tmax" iter " = " Tmax "; Cmax" iter " = " Cmax
endif
if iter == 7 then
include tfile
ff = 1 1 1 1 1
append file parStr " "
append file " " Rmax1 " " Rmax2 " " Rmax3 " " Rmax4 " " Rmax5 " " Rmax6 " " Rmax
append file " " Cmax1 " " Cmax2 " " Cmax3 " " Cmax4 " " Cmax5 " " Cmax6 " " Cmax
append file " " Tmax1 " " Tmax2 " " Tmax3 " " Tmax4 " " Tmax5 " " Tmax6 " " Tmax
append file " "
endif
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%