/* Author: Xu Zhang @UConn, Jul., 2018
ION: inferior olivary nucleus neurons
Modified from Schweighofer et al., 1999 and Torben-Nielson et al., 2012
*/
// To execute this script individually, please specify the following variables, e.g.:
// IONrnd = 101 // rng seed
// IONexrnd = 102
// IONexstrnd = 103
// IONgapjgrnd = 104
// noiseSwitch=1
// dt = 0.0125
create IONcell[40]
for i = 0,39 {
access IONcell[i]
IONcell[i].nseg = 1
IONcell[i].L = 20
IONcell[i].diam = 20
IONcell[i].cm = 1 // (uF/cm2)
insert ioKdr
insert ioNa
insert ioCa
insert pas
insert ioh
IONcell[i].ek = -70 // (mV)
IONcell[i].ena = 55 // (mV)
IONcell[i].e_pas = -63
IONcell[i].gbar_ioKdr = 9 // (mS/cm2)
IONcell[i].gbar_ioNa = 37 //+i // (mS/cm2)
IONcell[i].gbar_ioh = 0.08 // (mS/cm2)
IONcell[i].gbar_ioCa = 0.27 // (mS/cm2)
// IONcell[i].gbar_ioh = 0.02 // (mS/cm2)
// IONcell[i].gbar_ioca = 0.3 // (mS/cm2) Harmaline
IONcell[i].g_pas = 0.13e-3 // +i*0.005e-3 // (S/cm2)
}
objref f_gapj
f_gapj = new File()
f_gapj.ropen("params_ION_gapj.txt")
IONgaptotal = f_gapj.scanvar()
double IONgapnum[40]
for i = 0,39 {
IONgapnum[i] = f_gapj.scanvar()
}
objref gapjunc[IONgaptotal]
gapjuncount = 0
for j = 0,39 {
for k = 0,IONgapnum[j]-1 {
IONcell[j] gapjunc[gapjuncount] = new iogap(0.9-0.1*k)
setpointer gapjunc[gapjuncount].vgap, IONcell[f_gapj.scanvar()-1].v(0.5)
gapjuncount = gapjuncount + 1
}
}
f_gapj.close()
max_gap_g = 5e-5
// Varying ION gap junction strengths
objref rngIONgapjg
rngIONgapjg = new Random(IONgapjgrnd)
rngIONgapjg.uniform(0.3,0.7)
for i = 0,IONgaptotal-1 {
gapjunc[i].g = rngIONgapjg.repick() * max_gap_g * 1.5
}
// Offset current
objref ION_oc_file
ION_oc_file = new File()
ION_oc_file.ropen("params_ION_oc.txt")
objref ocION[40]
for i = 0,39 {
IONcell[i] ocION[i] = new IClamp(0.5)
ocION[i].amp = ION_oc_file.scanvar() // Normal
ocION[i].del = 0
ocION[i].dur = 1e10
}
ION_oc_file.close()
// External source of input to IO (that generate a <1 Hz firing rate in the absence of NO-IO pathway)
objref rngIONex, rngIONexst
rngIONex = new Random(IONexrnd)
rngIONex.uniform(350,650)
rngIONexst = new Random(IONexstrnd)
rngIONexst.uniform(50,200)
objref EX2ION_syn_exc[40], EX2IONns[40], EX2IONnsnc[40]
// Initialize
excount = 0
tmpinterval = rngIONex.repick()
tmpstart =rngIONexst.repick()
for i = 0,39 {
excount_new = int(i/8)
IONcell[i] EX2ION_syn_exc[i] = new NoisyExp2Syn(0.35)
EX2ION_syn_exc[i].tau1 = 2 // (ms)
EX2ION_syn_exc[i].tau2 = 10 // (ms)
EX2ION_syn_exc[i].e = 0
IONcell[i] EX2IONns[i] = new NetStim(0.2)
EX2IONns[i].number=1e4
EX2IONns[i].noise=1
if (excount_new>excount) {
tmpinterval = rngIONex.repick()
tmpstart =rngIONexst.repick()
excount = excount_new
}
EX2IONns[i].interval=tmpinterval
EX2IONns[i].start=tmpstart
IONcell[i] EX2IONnsnc[i] = new NetCon(EX2IONns[i], EX2ION_syn_exc[i], 0, 0, 1.5e-5)
}
// Membrane noise in IO
objref ION_noisc, IONnoise[40]
ION_noisc = new Random(IONrnd)
ION_noisc.normal(0, 1e-5*noiseSwitch)
for i = 0,39 {
IONcell[i] IONnoise[i] = new NoisyCurrent(0.2)
ION_noisc.play(&IONnoise[i].noise)
}