/* Author: Xu Zhang @UConn, Jul., 2018
Motor cortical neurons: PYN and FSI (abbreviated as PY and FS in the script, respectively)
Modified from Destexhe et al., 1998
*/
// To execute this script individually, please specify the following variables, e.g.:
// PY2PYrnd = 106 // rng seed
// PYrnd = 107
// PYNintrnd = 207
// FSIintrnd = 307
// noiseSwitch=1
// dt = 0.0125
celsius = 36
// Low-threshold spiking pyramidal neurons * 20
create PYcell[20]
objref ocPY[20]
for i = 0,19 {
access PYcell[i]
PYcell[i].Ra = 100 // geometry
PYcell[i].nseg = 1
PYcell[i].diam = 96
PYcell[i].L = 96 // such that area is about 58000 um2
PYcell[i].cm = 1
insert pas
insert mchh2
insert mcIm
insert mcCad
insert mcIt
// pas
// PYcell[i].e_pas = -70
// PYcell[i].g_pas = 1e-5
PYcell[i].ek = -100
PYcell[i].ena = 50
// hh2
PYcell[i].vtraub_mchh2 = -55 // Resting Vm, BJ was -55
// PYcell[i].gnabar_hh2 = 0.05 // McCormick=15 muS, thal was 0.09
// PYcell[i].gkbar_hh2 = 0.005 // spike duration of pyr cells
// im
taumax_im = 1000
// PYcell[i].gkbar_im = 3e-5 // specific to LTS pyr cell
// cad
PYcell[i].depth_mcCad = 1 // McCormick= 0.1 um
PYcell[i].taur_mcCad = 5 // McCormick=1 ms !!!
PYcell[i].cainf_mcCad = 2.4e-4 // McCormick=0
PYcell[i].kt_mcCad = 0 // no pump
// it
PYcell[i].cai = 2.4e-4
PYcell[i].cao = 2
PYcell[i].eca = 120
// PYcell[i].gcabar_it = 0.001 // specific to LTS pyr cell
// Change parameters to LTS
PYcell[i].gcabar_mcIt = 4e-4
PYcell[i].gkbar_mcIm = 3e-5
PYcell[i].g_pas = 1e-5
PYcell[i].e_pas = -85
PYcell[i].gnabar_mchh2 = 0.05
PYcell[i].gkbar_mchh2 = 0.005
PYcell[i] ocPY[i] = new IClamp(0.5)
ocPY[i].amp = 0.17 // (nA) Simulate baseline activity
ocPY[i].del = 0
ocPY[i].dur = 1e10
}
// Connect PY2PY
objref PY2PYsyn[40]
// Random interconnections among PYNs
objref rngPYNint
rngPYNint = new Random(PYNintrnd)
rngPYNint.normal(1,0.04)
// Synaptic noise within PY
objref PYi_noisyn
PYi_noisyn = new Random(PY2PYrnd)
PYi_noisyn.normal(0, 1e-6*noiseSwitch)
PYcell[0] PY2PYsyn[0] = new tanhSyn(0.6)
setpointer PY2PYsyn[0].vpre, PYcell[19].v(0.5)
PY2PYsyn[0].g = PY2PYsyn[0].g * abs(rngPYNint.repick()) * 100
PYcell[0] PY2PYsyn[20] = new tanhSyn(0.6)
setpointer PY2PYsyn[20].vpre, PYcell[1].v(0.5)
PY2PYsyn[20].g = PY2PYsyn[20].g * abs(rngPYNint.repick()) * 100
for i = 1,18 {
PYcell[i] PY2PYsyn[i] = new tanhSyn(0.6)
setpointer PY2PYsyn[i].vpre, PYcell[i-1].v(0.5)
PY2PYsyn[i].g = PY2PYsyn[i].g * abs(rngPYNint.repick()) * 100
PYcell[i] PY2PYsyn[i+20] = new tanhSyn(0.6)
setpointer PY2PYsyn[i+20].vpre, PYcell[i+1].v(0.5)
PY2PYsyn[i+20].g = PY2PYsyn[i+20].g * abs(rngPYNint.repick()) * 100
}
PYcell[19] PY2PYsyn[19] = new tanhSyn(0.6)
setpointer PY2PYsyn[19].vpre, PYcell[18].v(0.5)
PY2PYsyn[19].g = PY2PYsyn[19].g * abs(rngPYNint.repick()) * 100
PYcell[19] PY2PYsyn[39] = new tanhSyn(0.6)
setpointer PY2PYsyn[39].vpre, PYcell[0].v(0.5)
PY2PYsyn[39].g = PY2PYsyn[39].g * abs(rngPYNint.repick()) * 100
for i = 0,19 {
// Synaptic noise
PYi_noisyn.play(&PY2PYsyn[i].noise)
}
// Fast-spiking interneurons * 2
create FScell[2]
objref OCFS[2]
for i = 0,1 {
access FScell[i]
FScell[i].Ra = 100 // geometry
FScell[i].nseg = 1
FScell[i].diam = 67
FScell[i].L = 67 // such that area is about 29000 um2
FScell[i].cm = 1
insert pas
insert mchh2
// pas
FScell[i].ek = -100
FScell[i].ena = 50
// hh2
FScell[i].vtraub_mchh2 = -55 // Resting Vm, BJ was -55
FScell[i].g_pas = 0.00015
FScell[i].e_pas = -70
FScell[i].gnabar_mchh2 = 0.05
FScell[i].gkbar_mchh2 = 0.01
FScell[i] OCFS[i] = new IClamp(0.5)
OCFS[i].amp = 0.15 // (nA) Simulate background excitation from prefrontal cortex
OCFS[i].del = 0
OCFS[i].dur = 1e10
}
// Connect FS2FS
objref FS2FSsyn[2]
for i = 0,1 {
FScell[i] FS2FSsyn[i] = new tanhSyn(0.6)
FS2FSsyn[i].alpha = 5
FS2FSsyn[i].tau = 5.56
FS2FSsyn[i].e = -80
FS2FSsyn[i].g = 0.0015
}
setpointer FS2FSsyn[0].vpre, FScell[1].v(0.5)
setpointer FS2FSsyn[1].vpre, FScell[0].v(0.5)
for i = 0,1 {
// Synaptic noise
PYi_noisyn.play(&FS2FSsyn[i].noise)
}
// Connect PY2FS
objref PY2FSsyn[40]
for i = 0,19 {
FScell[0] PY2FSsyn[i] = new tanhSyn(0.7+0.01*i)
setpointer PY2FSsyn[i].vpre, PYcell[i].v(0.5)
PY2FSsyn[i].g = 0.0025
FScell[1] PY2FSsyn[i+20] = new tanhSyn(0.7+0.01*i)
setpointer PY2FSsyn[i+20].vpre, PYcell[i].v(0.5)
PY2FSsyn[i+20].g = 0.0025
}
// Connect FS2PY
objref FS2PYsyn[40]
// Random interconnections FSI-PYN
objref rngFSIint
rngFSIint = new Random(FSIintrnd)
rngFSIint.normal(1,0.0256)
for i = 0,19 {
PYcell[i] FS2PYsyn[i] = new tanhSyn(0.7)
setpointer FS2PYsyn[i].vpre, FScell[0].v(0.5)
FS2PYsyn[i].alpha = 5
FS2PYsyn[i].tau = 5.56
FS2PYsyn[i].e = -80
FS2PYsyn[i].g = 2.2e-2 * abs(rngFSIint.repick()) // * 0.8
PYcell[i] FS2PYsyn[i+20] = new tanhSyn(0.8)
setpointer FS2PYsyn[i+20].vpre, FScell[1].v(0.5)
FS2PYsyn[i+20].alpha = 5
FS2PYsyn[i+20].tau = 5.56
FS2PYsyn[i+20].e = -80
FS2PYsyn[i+20].g = 2.2e-2 * abs(rngFSIint.repick()) // * 0.8
}
for i = 0,39 {
// Synaptic noise
PYi_noisyn.play(&PY2FSsyn[i].noise)
PYi_noisyn.play(&FS2PYsyn[i].noise)
}
// Membrane noise in PY
objref MC_noisc, PYnoise[20], FSnoise[2]
MC_noisc = new Random(PYrnd)
MC_noisc.normal(0, 1e-1*noiseSwitch)
for i = 0,19 {
PYcell[i] PYnoise[i] = new NoisyCurrent(0.2)
MC_noisc.play(&PYnoise[i].noise)
}
// Membrane noise in FS
for i = 0,1 {
FScell[i] FSnoise[i] = new NoisyCurrent(0.2)
MC_noisc.play(&FSnoise[i].noise)
}