%% this funcion is used in fractional neuron integration. It integrates the fractional derivative and the voltage v at each time t.
function out=runNetworkderivativeHHFractionalPotassium(NetProp,Iinj,t,alpha)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Ncells=NetProp.Ncells;
dt=NetProp.dt;
Cm=NetProp.Cm;
v0=NetProp.v0;
vrest=NetProp.vrest;
gK=NetProp.gK;
gNa=NetProp.gNa;
gL=NetProp.gL;
EK=NetProp.EK;
ENa=NetProp.ENa;
EL=NetProp.EL;
m=NetProp.m;
h=NetProp.h;
n=NetProp.n;
Namp=NetProp.Noise;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
v=vrest.*ones(length(t),Ncells);
dVdt=zeros(length(t)-1,Ncells);
dVdtnow =dVdt(1,:);
mV=m*ones(length(t),Ncells);
hV=h*ones(length(t),Ncells);
nV=n*ones(length(t),Ncells);
VMemory=zeros(length(t)-1,Ncells);
Ngatememory=zeros(length(t)-1,Ncells);
I_HionicV=0*ones(length(t),Ncells);
INaV=0*ones(length(t),Ncells);
IKV=0*ones(length(t),Ncells);
ILV=0*ones(length(t),Ncells);
Noise=Namp*randn(length(t),Ncells);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% The weight for the voltage memory trace of the fractional drivative for
% calculated here for the total time t for faster simulation
memW=250; %FIDEL: to cap the length of the memory trace. 200 ms captures 96% of the curve
lastW=200;
NN=length(t);
nn=1:NN-1;
WCoet=(NN+1-nn).^(1-alpha)-(NN-nn).^(1-alpha);
% Iionic=@(v,m,h,n,gbarL,gbarNa,gbarK,vrest,Ena,Ek)((gL*(v-EL)+...
% gNa*m^3*h*(v-Ena)+...
% gK*n^4*(v-Ek)));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
preT=1;%:length(t)-1;
%it integrates the first step as classical HH
for a=preT;
[v(a+1,1),m,h,n,dVdtnow]=HH_RKfull(v(a,1),m,h,n,gL,gNa,gK,EL,ENa,EK,Iinj(a),Cm,dt,v0);
mV(a+1,:) = m;
hV(a+1,:) = h;
nV(a+1,:) = n;
dVdt(a,:)=dVdtnow;
VMemory(a,:)=0;
Ngatememory(a,:)=0;
end
kr = dt^alpha*gamma(2-alpha); % the kernel from the fractional derivative and weighted the markovian term
mf=@(Mm,V)(((2.5-0.1.*(V-v0))./(exp(2.5-0.1.*(V-v0))-1))*(1-Mm)-(4.*exp(-(V-v0)./18))*Mm);
hf=@(Hh,V)((0.07*exp(-(V-v0)/20))*(1-Hh)-(1./(exp(3-0.1*(V-v0))+1))*Hh);
f=@(v,m,h,n,I)(-(1/Cm)*(gL*(v-EL)+gNa*m^3*h*(v-ENa)+gK*n^4*(v-EK))+I);
DeltaN=diff(nV,1,1);
for a=(preT(end)+1):length(t)-1
%Iionic =gL*(v(a,1)-EL)+gNa*m^3*h*(v(a,1)-ENa)+gK*n^4*(v(a,1)-EK);
%[v(a+1,1),m,h,dVdtnow]=HH_RK(v(a,1),m,h,n,dt,Iinj(a));
%the RK integration
k1=mf(mV(a),v(a,1));
k2=mf(mV(a)+(dt/2)*k1,v(a,1));
k3=mf(mV(a)+(dt/2)*k2,v(a,1));
k4=mf(mV(a)+dt*k3,v(a,1));
mV(a+1)=mV(a)+(dt/6)*(k1+2*k2+2*k3+k4);
k1=hf(hV(a),v(a,1));
k2=hf(hV(a)+(dt/2)*k1,v(a,1));
k3=hf(hV(a)+(dt/2)*k2,v(a,1));
k4=hf(hV(a)+dt*k3,v(a,1));
hV(a+1)=hV(a)+(dt/6)*(k1+2*k2+2*k3+k4);
k1=f(v(a),mV(a),hV(a),nV(a),Iinj(a));
k2=f(v(a)+(dt/2)*k1,mV(a),hV(a),nV(a),Iinj(a));
k3=f(v(a)+(dt/2)*k2,mV(a),hV(a),nV(a),Iinj(a));
k4=f(v(a)+dt*k3,mV(a),hV(a),nV(a),Iinj(a));
v(a+1,1)=v(a)+(dt/6)*(k1+2*k2+2*k3+k4);
dVdt(a,:)=k1;
%[m,h,n]=HH_RK(v(a,1),m,h,n,dt,1);
%mV(a+1,:) = mnew;
%hV(a+1,:) = hnew;
%dVdt(a, :)=dVdtnow;
% %%%%% The weight of the memory trace
% WCoe=WCoet(end-a+2:end); % The weight for the voltage memory trace of the fractional drivative at each tiime t
% %%% Memory trace for for gating variable n
% DeltaN =nV(2:a,:)-nV(1:a-1,:);
%%%%% The weight of the memory trace
%WCoe=WCoet((NN-a+1):(NN-1)); % The weight for the voltage memory trace of the fractional drivative at each tiime t
%%% Memory trace for for gating variable n
%DeltaN =diff(nV(1:a,:),1,1);%nV(2:a,:)-nV(1:a-1,:);
%NgateMemory=WCoe*DeltaN;
DeltaN(a-1,:)=diff(nV(a-1:a,:),1,1);
NgateMemory=WCoet((NN-a+1):(NN-1))*DeltaN(1:a-1,:);
Ngatememory(a,:)= NgateMemory;
alphan=(0.1-0.01*(v(a,1)-v0))./(exp(1-0.1*(v(a,1)-v0))-1);
betan=0.125.*exp(-(v(a,1)-v0)./80);
n = kr*(alphan*(1-nV(a,1))-betan*nV(a,1))+nV(a,1)-NgateMemory;% + Noise(a,1);
nV(a+1,:) = n;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
end
out.v=v;
%out. VMemory= VMemory;
out.t=t;
%out.fraccalcu=fraccalcu;
%out.I_Hionic=0;%I_Hionic;
%out.INa=INa;
%out.IK=IK;
%out.IL=IL;
out.mV=mV;
out.nV=nV;
out.hV=hV;
out.Ngatememory= Ngatememory;
out.dVdt= dVdt;
end
function [vnew,mnew,hnew,dVdtnew]=HH_RK(vold,mold,h1old,nold,dt,Iapp)
v0=-65;
V=vold;
alpham=(2.5-0.1.*(V-v0))./(exp(2.5-0.1.*(V-v0))-1);
betam=4.*exp(-(V-v0)./18);
alphah=0.07*exp(-(V-v0)/20);
betah=1./(exp(3-0.1*(V-v0))+1);
mf=@(Mm)(alpham*(1-Mm)-betam*Mm);
hf=@(Hh)(alphah*(1-Hh)-betah*Hh);
%%%%%%%%
k1=mf(mold);
k2=mf(mold+(dt/2)*k1);
k3=mf(mold+(dt/2)*k2);
k4=mf(mold+dt*k3);
mnew=mold+(dt/6)*(k1+2*k2+2*k3+k4);
k1=hf(h1old);
k2=hf(h1old+(dt/2)*k1);
k3=hf(h1old+(dt/2)*k2);
k4=hf(h1old+dt*k3);
hnew=h1old+(dt/6)*(k1+2*k2+2*k3+k4);
%%%%%%%%%%%
gK=36; gNa=120; gL=0.3; % channel conductances: mS/cm2
EK=-12 + v0(1,1); ENa=115 + v0(1,1); EL=10.6 + v0(1,1); % channel reversal potentials: mV
Cm=1;
f=@(v,m,h,n,I)(-(1/Cm)*(gL*(v-EL)+gNa*m^3*h*(v-ENa)+gK*n^4*(v-EK))+I);
k1=f(vold,mold,h1old,nold,Iapp);
k2=f(vold+(dt/2)*k1,mold,h1old,nold,Iapp);
k3=f(vold+(dt/2)*k2,mold,h1old,nold,Iapp);
k4=f(vold+dt*k3,mold,h1old,nold,Iapp);
vnew=vold+(dt/6)*(k1+2*k2+2*k3+k4);
dVdtnew=k1;
end
function [vnew,mnew,hnew,nnew,dVdtnew]=HH_RKfull(vold,mold,h1old,nold,gbarL,gbarNa,gbarK,vrest,Ena,Ek,Im,Cm,dt,alpha)
v0=-65;
V=vold;
alpham=(2.5-0.1.*(V-v0))./(exp(2.5-0.1.*(V-v0))-1);
betam=4.*exp(-(V-v0)./18);
alphah=0.07*exp(-(V-v0)/20);
betah=1./(exp(3-0.1*(V-v0))+1);
alphan=(0.1-0.01*(V-v0))./(exp(1-0.1*(V-v0))-1);
betan=0.125.*exp(-(V-v0)./80);
mf=@(Mm)(alpham*(1-Mm)-betam*Mm);
hf=@(Hh)(alphah*(1-Hh)-betah*Hh);
nf=@(Nna)(alphan*(1-Nna)-betan*Nna);
f=@(v,m,h,n,gbarL,gbarNa,gbarK,vrest,Ena,Ek,I,Cm)(-(1/Cm)*(gbarL*(v-vrest)+...
gbarNa*m^3*h*(v-Ena)+...
gbarK*n^4*(v-Ek))+...
I);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
k1=f(vold,mold,h1old,nold,gbarL,gbarNa,gbarK,vrest,Ena,Ek,Im,Cm);
k2=f(vold+(dt/2)*k1,mold,h1old,nold,gbarL,gbarNa,gbarK,vrest,Ena,Ek,Im,Cm);
k3=f(vold+(dt/2)*k2,mold,h1old,nold,gbarL,gbarNa,gbarK,vrest,Ena,Ek,Im,Cm);
k4=f(vold+dt*k3,mold,h1old,nold,gbarL,gbarNa,gbarK,vrest,Ena,Ek,Im,Cm);
vnew=vold+(dt/6)*(k1+2*k2+2*k3+k4);
dVdtnew =k1;
k1=mf(mold);
k2=mf(mold+(dt/2)*k1);
k3=mf(mold+(dt/2)*k2);
k4=mf(mold+dt*k3);
mnew=mold+(dt/6)*(k1+2*k2+2*k3+k4);
k1=hf(h1old);
k2=hf(h1old+(dt/2)*k1);
k3=hf(h1old+(dt/2)*k2);
k4=hf(h1old+dt*k3);
hnew=h1old+(dt/6)*(k1+2*k2+2*k3+k4);
k1=nf(nold);
k2=nf(nold+(dt/2)*k1);
k3=nf(nold+(dt/2)*k2);
k4=nf(nold+dt*k3);
nnew=nold+(dt/6)*(k1+2*k2+2*k3+k4);
end