Muscle spindle feedback circuit (Moraud et al, 2016)

 Download zip file 
Help downloading and running models
Accession:189786
Here, we developed a computational model of the muscle spindle feedback circuits of the rat ankle that predicts the interactions between Epidural Stimulation and spinal circuit dynamics during gait.
Reference:
1 . Moraud EM, Capogrosso M, Formento E, Wenger N, DiGiovanna J, Courtine G, Micera S (2016) Mechanisms Underlying the Neuromodulation of Spinal Circuits for Correcting Gait and Balance Deficits after Spinal Cord Injury. Neuron 89:814-28 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism: Spinal motoneuron;
Cell Type(s): Spinal cord motor neuron slow twitch;
Channel(s): I K; I K,Ca; I Na,p; I Sodium;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON; Python;
Model Concept(s): Sensory processing; Neuromodulation;
Implementer(s): Capogrosso, Marco ; Formento, Emanuele ;
Search NeuronDB for information about:  I Na,p; I K; I K,Ca; I Sodium;
//DEFINITION OF LIST VARIABLES
objref cells, nclist, netcon, stim, nc, nil
{cells = new List()  nclist = new List() stim= new List()}

func cell_append() {cells.append($o1)  $o1.position($2,$3,$4)
	return cells.count - 1
}

//Compute indexes in the different hosts
func computeInd() { // nCells
  StimInd_0 = int($1/pc.nhost)
  if (pc.id < $1%pc.nhost){StimInd_0+=1}
  return  StimInd_0
}

nFiber=nIAf+nIIf
nNeurons=nMN+nIAint+nEXIN // all the types of cells
nStim=1 + 2*nIAf //1 EES + IAnat
nCell=nNeurons+nFiber

objectvar AP_MN_Flex[computeInd(nMN)]
objectvar AP_IA_Flex[computeInd(nIAf)]
objectvar AP_IAInt_Flex[computeInd(nIAint)]
objectvar AP_II_Flex[computeInd(nIIf)]
objectvar AP_EXIN_Flex[computeInd(nEXIN)]

objectvar AP_MN_Ext[computeInd(nMN)]
objectvar AP_IA_Ext[computeInd(nIAf)]
objectvar AP_IAInt_Ext[computeInd(nIAint)]
objectvar AP_II_Ext[computeInd(nIIf)]
objectvar AP_EXIN_Ext[computeInd(nEXIN)]

//CELLS DEFINITIONS
//Flexors
//MOTORNEURONS
// each host gets every nhost'th cell, starting from the id of the host
// and continuing until all cells have been dealt out
count=0
for (i=pc.id; i < nMN; i += pc.nhost) {
    {cell_append(new M_Cell(),200+i*10, 200, 200)}
    {cells.object(cells.count()-1).geom(i)}
    {cells.object(cells.count()-1).synapses(i)}
    pc.set_gid2node(i, pc.id) // associate gid i with this host
    nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell - nil doesn't have to be a real target
    AP_MN_Flex[count]= new Vector()
    nc.record(AP_MN_Flex[count])
    pc.cell(i, nc) // associate gid i with spike detector
    count+=1
}

//IA_fiber
count=0
for (i=pc.id+nMN; i < nIAf+nMN; i += pc.nhost) {
  {cell_append(new IA_fiber(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_IA_Flex[count]= new Vector()
  nc.record(AP_IA_Flex[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//IA_Int
count=0
for (i=pc.id+nIAf+nMN; i < nIAint+nIAf+nMN; i += pc.nhost) {
  {cell_append(new IA_Int(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_IAInt_Flex[count]= new Vector()
  nc.record(AP_IAInt_Flex[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//II_fiber
count=0
for (i=pc.id+nIAf+nMN+nIAint; i < nIAint+nIAf+nMN+nIIf; i += pc.nhost) {
  {cell_append(new II_fiber(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_II_Flex[count]= new Vector()
  nc.record(AP_II_Flex[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//EXINT
count=0
for (i=pc.id+nIAint+nIAf+nMN+nIIf; i < nIAint+nIAf+nMN+nIIf+nEXIN; i += pc.nhost) {
  {cell_append(new IA_Int(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_EXIN_Flex[count]= new Vector()
  nc.record(AP_EXIN_Flex[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}
//END FLEXORs


//EXTENSORS
//MOTORNEURONS
// each host gets every nhost'th cell, starting from the id of the host
// and continuing until all cells have been dealt out
count = 0
for (i=pc.id+nCell; i < nMN+nCell; i += pc.nhost) {
    {cell_append(new M_Cell(),200+i*10, 200, 200)}
    {cells.object(cells.count()-1).geom(i-nCell)}
    {cells.object(cells.count()-1).synapses(i-nCell)}
    {pc.set_gid2node(i, pc.id)} // associate gid i with this host
    {nc = cells.object(cells.count()-1).connect2target(nil)}// attach spike detector to cell
    {AP_MN_Ext[count]= new Vector()}
    {nc.record(AP_MN_Ext[count])}
    {pc.cell(i, nc)} // associate gid i with spike detector
    {count+=1}
}

//IA_fiber
count = 0
for (i=pc.id+nMN+nCell; i < nIAf+nMN+nCell; i += pc.nhost) {
  {cell_append(new IA_fiber(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_IA_Ext[count]= new Vector()
  nc.record(AP_IA_Ext[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//IA_Int
count = 0
for (i=pc.id+nIAf+nMN+nCell; i < nIAint+nIAf+nMN+nCell; i += pc.nhost) {
  {cell_append(new IA_Int(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_IAInt_Ext[count]= new Vector()
  nc.record(AP_IAInt_Ext[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//II_fiber
count = 0
for (i=pc.id+nIAint+nIAf+nMN+nCell; i < nIAint+nIAf+nMN+nCell+nIIf; i += pc.nhost) {
  {cell_append(new II_fiber(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_II_Ext[count]= new Vector()
  nc.record(AP_II_Ext[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//EXINT
count = 0
for (i=pc.id+nIAint+nIAf+nMN+nCell+nIIf; i < nIAint+nIAf+nMN+nCell+nIIf+nEXIN; i += pc.nhost) {
  {cell_append(new IA_Int(),0,0,0)}
  pc.set_gid2node(i, pc.id) // associate gid i with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  AP_EXIN_Ext[count]= new Vector()
  nc.record(AP_EXIN_Ext[count])
  pc.cell(i, nc) // associate gid i with spike detector
  count+=1
}

//END EXTENSORS
//END CELLS DEFINITION


//EES
// create EES only in the first host
if (pc.id == 0) {
  {cell_append(new EES(),0,0,0)}
  pc.set_gid2node(nCell*2, pc.id) // associate gid nCell*2 with this host
  nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
  pc.cell(nCell*2, nc)
}

//FLEXORS STIM
//IA_nat
Ind_IaFibStimFlex = nCell*2+1
count = 0
for (freq=50; freq>=20; freq-=10){  // >40 - 40 - 30 - 20 Hz with simulation step (changeParam in runSimulation method of the network class in python) of 20 ms
  for (i=pc.id; i < nIAf; i += pc.nhost) {
    {cell_append(new  IA_fiber_stim(),0,0,0)}
    pc.set_gid2node(Ind_IaFibStimFlex+nIAf*count+i, pc.id) // associate gid i with this host
    nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
    pc.cell(Ind_IaFibStimFlex+nIAf*count+i, nc) // associate gid i with spike detector
    cells.object(cells.count()-1).pp.interval = 1000/freq
  }
  count+=1
}

//II_nat
Ind_IIFibStimFlex = Ind_IaFibStimFlex + 4*nIAf
count = 0
for (freq=50; freq>=20; freq-=10){  // >40 - 40 - 30 - 20 Hz with simulation step of 20 ms
  for (i=pc.id; i < nIIf; i += pc.nhost) {
    {cell_append(new  II_fiber_stim(),0,0,0)}
    pc.set_gid2node(Ind_IIFibStimFlex+nIIf*count+i, pc.id) // associate gid i with this host
    nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
    pc.cell(Ind_IIFibStimFlex+nIIf*count+i, nc) // associate gid i with spike detector
    cells.object(cells.count()-1).pp.interval = 1000/freq
  }
  count+=1
}


//EXTENSORS STIM
//IA_nat
Ind_IaFibStimExt = Ind_IIFibStimFlex + 4*nIIf
count = 0
for (freq=50; freq>=20; freq-=10){  // >40 - 40 - 30 - 20 Hz with simulation step of 20 ms
  for (i=pc.id; i < nIAf; i += pc.nhost) {
    {cell_append(new  IA_fiber_stim(),0,0,0)}
    pc.set_gid2node(Ind_IaFibStimExt+nIAf*count+i, pc.id) // associate gid i with this host
    nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
    pc.cell(Ind_IaFibStimExt+nIAf*count+i, nc) // associate gid i with spike detector
    cells.object(cells.count()-1).pp.interval = 1000/freq
  }
  count+=1
}

//II_nat
Ind_IIFibStimExt = Ind_IaFibStimExt + 4*nIAf
count = 0
for (freq=50; freq>=20; freq-=10){  // >40 - 40 - 30 - 20 Hz with simulation step of 20 ms
  for (i=pc.id; i < nIAf; i += pc.nhost) {
    {cell_append(new  II_fiber_stim(),0,0,0)}
    pc.set_gid2node(Ind_IIFibStimExt+nIIf*count+i, pc.id) // associate gid i with this host
    nc = cells.object(cells.count()-1).connect2target(nil) // attach spike detector to cell
    pc.cell(Ind_IIFibStimExt+nIIf*count+i, nc) // associate gid i with spike detector
    cells.object(cells.count()-1).pp.interval = 1000/freq
  }
  count+=1
}


//SYNAPTIC CONNECTIONS
//FLEXORS
{xopen("SynFlexFlex.hoc")}
//EXTENSORS
{xopen("SynExtExt.hoc")}
//Crossing
{xopen("SynExtFlex.hoc")}
//Stimulations
{xopen("Stim.hoc")}
//END SYNAPTIC CONNECTIONS

Loading data, please wait...