/*----------------------------------------------------------------------------
Simplified model of bursting cortical neuron
============================================
Single-compartment model of "rebound bursts" in pyramidal
neurons (type of cell very common in association areas of
cortex). The model is based on the presence of four
voltage-dependent currents:
- INa, IK: action potentials
- IM: slow K+ current for spike-frequency adaptation
- IT: T-type calcium currents for burst generation
Model described in:
Pospischil, M., Toledo-Rodriguez, M., Monier, C., Piwkowska, Z.,
Bal, T., Fregnac, Y., Markram, H. and Destexhe, A.
Minimal Hodgkin-Huxley type models for different classes of
cortical and thalamic neurons.
Biological Cybernetics 99: 427-441, 2008.
The model was originally published in the following reference:
Destexhe, A. Contreras, D. and Steriade, M.
LTS cells in cerebral cortex and their role in generating
spike-and-wave oscillations.
Neurocomputing 38: 555-563 (2001).
Alain Destexhe, CNRS, 2009
http://cns.iaf.cnrs-gif.fr
----------------------------------------------------------------------------*/
//----------------------------------------------------------------------------
// load and define general graphical procedures
//----------------------------------------------------------------------------
load_file("stdrun.hoc")
objectvar g[20] // max 20 graphs
ngraph = 0
proc addgraph() { local ii // define subroutine to add a new graph
// addgraph("variable", minvalue, maxvalue)
ngraph = ngraph+1
ii = ngraph-1
g[ii] = new Graph()
g[ii].size(tstart,tstop,$2,$3)
g[ii].xaxis()
g[ii].yaxis()
g[ii].addvar($s1,1,0)
g[ii].save_name("graphList[0].")
graphList[0].append(g[ii])
}
proc addtext() { local ii // define subroutine to add a text graph
// addtext("text")
ngraph = ngraph+1
ii = ngraph-1
g[ii] = new Graph()
g[ii].size(0,tstop,0,1)
g[ii].xaxis(3)
g[ii].yaxis(3)
g[ii].label(0.1,0.8,$s1)
g[ii].save_name("graphList[0].")
graphList[0].append(g[ii])
text_id = ii
}
proc addline() { // to add a comment to the text window
// addline("text")
g[text_id].label($s1)
}
nrnmainmenu() // create main menu
nrncontrolmenu() // crate control menu
//----------------------------------------------------------------------------
// transient time
//----------------------------------------------------------------------------
trans = 0000
print " "
print ">> Transient time of ",trans," ms"
print " "
//----------------------------------------------------------------------------
// create PY cells
//----------------------------------------------------------------------------
print " "
print "<<==================================>>"
print "<< CREATE CELLS >>"
print "<<==================================>>"
print " "
xopen("sPYr_template") // read geometry file
ncells = 1 // nb of cells in each layer <<>>
objectvar PY[ncells]
for i=0,ncells-1 {
PY[i] = new sPYr()
}
//----------------------------------------------------------------------------
// Rebound parameters
//----------------------------------------------------------------------------
// T-current density adjusted to delaPena & Geigo-Barrientos
PY[0].soma {
gcabar_it = 4e-4
gkbar_im = 3e-5
g_pas = 1e-5
e_pas = -85
gnabar_hh2 = 0.05
gkbar_hh2 = 0.005
}
// this parameter set (above) is for bursting behavior; for
// regular spiking:
// e_pas = -75
// El[0].stim.amp = 0.12
// LTS:
// e_pas = -60
// El[0].stim.amp = -0.075
// bursting:
// e_pas = -85
// El[0].stim.amp = 0.15
// classic RS and FS behavior are obtained by blocking IT and IM successively
//----------------------------------------------------------------------------
// insert electrode in each PY cell
//----------------------------------------------------------------------------
if(ismenu==0) {
load_file("electrod.hoc") // electrode template
ismenu = 1
}
objectvar El[ncells] // create electrodes
CURR_AMP = 0.15
for i=0,ncells-1 { // insert one in each cell
PY[i].soma El[i] = new Electrode()
PY[i].soma El[i].stim.loc(0.5)
El[i].stim.del = 400
El[i].stim.dur = 400
El[i].stim.amp = CURR_AMP
}
electrodes_present=1
//----------------------------------------------------------------------------
// setup simulation parameters
//----------------------------------------------------------------------------
Dt = .1 // macroscopic time step <<>>
npoints = 10000
dt = 0.1 // must be submultiple of Dt
tstart = trans
tstop = trans + npoints * Dt
runStopAt = tstop
steps_per_ms = 5
celsius = 36
v_init = -84
//----------------------------------------------------------------------------
// add graphs
//----------------------------------------------------------------------------
strdef gtxt
if(batch == 0) {
addgraph("PY[0].soma.m_im",0,1)
// addgraph("PY[0].soma.m_iahp",0,1)
for i=0,ncells-1 {
sprint(gtxt,"PY[%d].soma.v(0.5)",i)
addgraph(gtxt,-120,40)
}
}
//----------------------------------------------------------------------------
// add text
//----------------------------------------------------------------------------
access PY[0].soma
proc text() {
sprint(gtxt,"%d PY cells",ncells)
addtext(gtxt)
sprint(gtxt,"Passive: gleak=%g Eleak=%g",PY.soma.g_pas,PY.soma.e_pas)
addline(gtxt)
sprint(gtxt,"HH: gNa=%g, gK=%g, vtraub=%g",PY.soma.gnabar_hh2,\
PY.soma.gkbar_hh2,PY.soma.vtraub_hh2)
addline(gtxt)
sprint(gtxt,"IM: g=%g, taumax=%g",PY.soma.gkbar_im,taumax_im)
addline(gtxt)
sprint(gtxt,"Ca++: tau=%g, depth=%g, cainf=%g",taur_cad,depth_cad,cainf_cad)
addline(gtxt)
sprint(gtxt,"IT: g=%g",PY.soma.gcabar_it)
addline(gtxt)
}