# basic XPP code for Ratte et al. 2018 J Neurosci 14: 1788-1801 
# written by Steve Prescott, last modified July 9, 2016

##################
   
dv/dt = (Idc+Idc2(t)+Idc3(t)+I1a(t)+I1b(t)+I2a(t)+I2b(t)+I3a(t)+I3b(t)+I4a(t)+I4b(t)+I5a(t)+I5b(t)+I6a(t)+I6b(t)-gna*minf(V)*(V-Vna)-gk*w*(V-VK)-gl*(V-Vl)-gcan*p2*(v-Vcan)-gahp*q*(v-Vk)-gahp2*q2*(v-Vk)-gahp3*q3*(v-Vk)-gca*p*switch*(v-vca))/c
dw/dt = phi*(winf(V)-w)/tauw(V)



q' = (q_inf-q)/tau_q
q2' = (q2_inf-q2)/tau_q2
q3' = (q3_inf-q3)/tau_q3


# for new AD current
param gcan=2
param Vcan=0
p2inf =1/(1+exp((cai-caihalf)/caislope))
param caihalf=.0004
# Cai in microM range
param caislope=-0.0002
p2' = (p2inf-p2)/tau_p2
param tau_p2=1
# essentially instantaneous with change in Cai


# for ca influx and decay
dcai/dt = (-SAvol*(gca*p*(V-Vca)))/F-(cai-0)/tau_ca
#dcai/dt = ((-SAvol*(gca*p*(V-Vca)))/F-(cai-0))/tau_ca - original in correct
p' = (p_inf-p)/tau_p
p_inf = 1/(1+exp((v-vhalfp)/vslopep))
param gca=0.005
# gca also gets 10^-3 shift
param switch=1
param vhalfp=0
param vslopep=-5
param tau_p=1
p(0)=0
cai(0)=0
vca=100
param F=96485
param tau_ca=2000
# lengthened so that CAN persists during prolonged hyperpol steps

# FOR SPHERICAL SOMA
param shape=3
# shape=3 for sphere, shape=2 for cylinder
!SAvol=shape/(10*r)
param r=0.01
# 10 micron radius soma
# p2

# for AHP current
q_inf = 1/(1+exp((v-vhalfq)/vslopeq))
param gahp=0
param vhalfq=0
param vslopeq=-5
param tau_q=25
q(0)=0

q2_inf = 1/(1+exp((v-vhalfq2)/vslopeq2))
param gahp2=50
param vhalfq2=0
param vslopeq2=-5
param tau_q2=200
q2(0)=0

q3_inf = 1/(1+exp((v-vhalfq3)/vslopeq3))
param gahp3=25
param vhalfq3=0
param vslopeq3=-5
param tau_q3=2000
q3(0)=0
#all three gahps are the same except for tau, and adjustments to their density

V(0)=-70
w(0)=0.000025
minf(v)=.5*(1+tanh((v-v1)/v2))
winf(v)=.5*(1+tanh((v-v3)/v4))
tauw(v)=1/cosh((v-v3)/(2*v4))
param vk=-90,vl=-70,vna=50
param gk=20,gl=2,gna=20
param v1=-1.2,v2=18
param v3=0,v4=10
param phi=.15,c=2

# STIMULATION
param idc=0
# use these to trigger spikes... t_run is short to that 1 spike is triggered per pulse
I1a(t)=sign(t>t_start1)*I_stim_a
I1b(t)=sign(t>(t_start1+t_run))*(-1*I_stim_a)
I2a(t)=sign(t>t_start2)*I_stim_a
I2b(t)=sign(t>(t_start2+t_run))*(-1*I_stim_a)
I3a(t)=sign(t>t_start3)*I_stim_a
I3b(t)=sign(t>(t_start3+t_run))*(-1*I_stim_a)
I4a(t)=sign(t>t_start4)*I_stim_a
I4b(t)=sign(t>(t_start4+t_run))*(-1*I_stim_a)
I5a(t)=sign(t>t_start5)*I_stim_a
I5b(t)=sign(t>(t_start5+t_run))*(-1*I_stim_a)
I6a(t)=sign(t>t_start6)*I_stim_a
I6b(t)=sign(t>(t_start6+t_run))*(-1*I_stim_a)
# use this to introduce sustained depol or hyperpol
Idc2(t)=sign(t>t_startDC2)*Idc2_
Idc3(t)=sign(t>t_startDC3)*Idc3_

param I_stim_a=90,t_start1=1100,t_start2=1200,t_start3=1300,t_start4=1400,t_start5=1500,t_start6=1600,t_run=5
param Idc2_=0,t_startDC2=4000,Idc3_=0,t_startDC3=6000

@ total=4000,dt=.1,xlo=1000,xhi=4000,ylo=-70,yhi=40,xp=t,yp=v
@ meth=runge-kutta
@ MAXSTOR=10000000

done