% this function is integrating the 4-state model for 1s optostimulation;
% note that the photocurrent is not normalized
function Inik = Nikolic4stFitNew(t, ton, toff, PP)
g1 = PP(7); gama = PP(8);
% integrating with ode45
[T,y] = ode45(@Nik4stfitodeNew, t, [0 0 0 0], [], ton, toff, PP);
I = g1*(y(:,1)+gama*y(:,2));
Inik = I;
%Inik = I./max(I);