Thalamic quiescence of spike and wave seizures (Lytton et al 1997)

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Accession:9889
A phase plane analysis of a two cell interaction between a thalamocortical neuron (TC) and a thalamic reticularis neuron (RE).
Reference:
1 . Lytton WW, Contreras D, Destexhe A, Steriade M (1997) Dynamic interactions determine partial thalamic quiescence in a computer network model of spike-and-wave seizures. J Neurophysiol 77:1679-96 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism: Thalamus;
Cell Type(s): Thalamus geniculate nucleus (lateral) principal neuron; Thalamus reticular nucleus cell;
Channel(s): I T low threshold;
Gap Junctions:
Receptor(s): GabaA; Glutamate;
Gene(s):
Transmitter(s): Gaba; Glutamate;
Simulation Environment: NEURON;
Model Concept(s): Temporal Pattern Generation; Oscillations; Calcium dynamics;
Implementer(s): Lytton, William [billl at neurosim.downstate.edu]; Destexhe, Alain [Destexhe at iaf.cnrs-gif.fr];
Search NeuronDB for information about:  Thalamus geniculate nucleus (lateral) principal neuron; Thalamus reticular nucleus cell; GabaA; Glutamate; I T low threshold; Gaba; Glutamate;
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lytton97
README
AMPA.mod
calciumpump_destexhe.mod *
GABAB1.mod
GABALOW.mod
gen.mod
HH_traub.mod *
IAHP_destexhe.mod
ICAN_destexhe.mod
Ih_old.mod *
IT_wang.mod
IT2_huguenard.mod
nmda.mod
passiv.mod
presyn.mod *
pulse.mod *
rand.mod
boxes.hoc *
declist.hoc *
decvec.hoc *
default.hoc *
directory
fig7.gif
geom.hoc
grvec.hoc
init.hoc
jnphys77_1679.pdf
local.hoc *
mosinit.hoc
network.hoc
nrnoc.hoc *
params.hoc
presyn.inc *
queue.inc *
run.hoc
simctrl.hoc *
snshead.inc *
synq.inc *
xtmp
                            
// $Id: network.hoc,v 1.39 2002/07/04 17:02:07 billl Exp $

proc networkfile() { }                       // For remote loading

/*--------------------------------------------------*/
/*  GEOMETRY: define cells and synaptic connections */
/*--------------------------------------------------*/

cols = 1  // columns are assumed to be controlled by a single re cell
// tiers : defined in geom.hoc for use in template
//         gives number of tc cells in a column
objectvar col[cols]

for (i=0;i<cols;i=i+1) {
  col[i] = new Tcol(i)
}

/*----------------*/
/*  CONNECTIVITY  */
/*----------------*/

create nullseg
access nullseg
v = -1000

// provide connectivity between columns
// each tc projects to either side
// so the connections are into the re cells in each col
proc latconnect () { local lt, rt
  for (i=0;i<cols;i=i+1) {
    lt = (i - 1)%cols  // col to the left
    rt = (i + 1)%cols  // col to the right
    
    // gaba syns in re's point back to neighboring re's
    setpointer col[i].re.srgaba.pre, nullseg.v(0.5)	// re <- re(R)
    setpointer col[i].re.slgaba.pre, nullseg.v(0.5)	// re <- re(L)

    // glu syns in re's point back to tc's
    setpointer col[i].re.srglu.pre, nullseg.v(0.5)	// re <- tc1(R)
    setpointer col[i].re.slglu.pre, nullseg.v(0.5)	// re <- tc2(L)
    
    // gaba syns in tc's point back to re's
    setpointer col[i].tc[0].slgaba.pre, nullseg.v(0.5)	// tc0 <- re(L)
//    setpointer col[i].tc[1].srgaba.pre, nullseg.v(0.5)	// tc1 <- re(R)

  }
}
    
latconnect() 

/*----------------*/
/*  STIMULATION   */
/*----------------*/

access nullseg  // arbitrary choice to locate fake presynaptic compartment

objectvar pg
pg = new gen(0.5)   	// create random spike generator

// for now leave the stimulation syns out of the template
objectvar sreinamp[cols], sreinnm[cols], stcin[cols*tiers]

proc stimul () { local i,j,ij
  for(i=0; i<cols; i=i+1) {
    sreinamp[i] = new AMPA()
    col[i].re.soma sreinamp[i].loc(0.5)		/* postsynaptic is RE */
    setpointer sreinamp[i].pre, pg.x	        /* generator */
    
    sreinnm[i] = new NMDA()
    col[i].re.soma sreinnm[i].loc(0.5)		/* postsynaptic is RE */
    setpointer sreinnm[i].pre, pg.x	        /* generator */
    
    for(j=0; j<tiers; j=j+1) {
      ij = i*cols+j  // count through cols and tiers
      stcin[ij] = new AMPA()
      col[i].tc[j].soma stcin[ij].loc(0.5)		/* postsynaptic is RE */
      setpointer stcin[ij].pre, pg.x	        /* generator */
    }
  }
}

stimul()

// col[0].tc[0].soma setsyn(0,0,600,-0.01,0,0,0,3)
// col[0].tc[0].soma setsyn(0,0,1e10,-0.01,0,5,0,1)
access col[0].tc[0].soma

func alphafunc () { return imax*($1/taualf) * exp(-($1-taualf)/taualf) }
func expdecf () { return imax*exp(-$1/taualf) }
proc mkstimv () {
  vec.indgen(0,600,dt)
  // vec.apply("alphafunc")
  vec.apply("expdecf")
}
imax=-0.015
taualf=200
mkstimv()

objref icl
icl = new IClamp(0.5)
icl.amp = -0.01 
icl.dur=600

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