Synchronicity of fast-spiking interneurons balances medium-spiny neurons (Damodaran et al. 2014)

 Download zip file 
Help downloading and running models
Accession:156260
This study investigates the role of feedforward and feedback inhibition in maintaining the balance between D1 and D2 MSNs of the striatum. The synchronized firing of FSIs are found to be critical in this mechanism and specifically the gap junction connections between FSIs.
Reference:
1 . Damodaran S, Evans RC, Blackwell KT (2014) Synchronized firing of fast-spiking interneurons is critical to maintain balanced firing between direct and indirect pathway neurons of the striatum. J Neurophysiol 111:836-48 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism:
Cell Type(s): Neostriatum spiny direct pathway neuron; Neostriatum spiny indirect pathway neuron; Neostriatum fast spiking interneuron;
Channel(s):
Gap Junctions: Gap junctions;
Receptor(s): NMDA; Gaba;
Gene(s):
Transmitter(s):
Simulation Environment: GENESIS;
Model Concept(s): Detailed Neuronal Models; Parkinson's;
Implementer(s): Blackwell, Avrama [avrama at gmu.edu]; Damodaran, Sriraman [dsriraman at gmail.com];
Search NeuronDB for information about:  Neostriatum spiny direct pathway neuron; Neostriatum spiny indirect pathway neuron; NMDA; Gaba;
/
striatalnetwork
MScell
channels
unusedChannels
AddCaSpines.g *
addchans.g *
addchans.g~ *
addinput.g *
addoutput.g *
addoutput.g~
addoutput_old.g *
AddSynapticChannels.g *
connectCaChannels.g *
DA_files.txt *
globals.g
globals.g~
globals_old.g
globalsCaComp.g *
include_channels.g *
MScell.g~
MScell.p *
MScell_D1.g *
MScell_D1.g~
MScell_D1_old.g
MScell_D2.g *
MScell_D2.g~
MScell_D2_old.g
MScell08.p *
MScell08CM3_D1.p *
MScell08CM3_D2.p *
MScell08CM3_old.p
MScellSpine.g *
MScellSpineCtx.g *
MScellSpineTh.g *
MScellSyn.g~ *
MScellSyn_D1.g *
MScellSyn_D2.g *
parametersA.g~
parametersA_D1.g *
parametersA_D2.g *
parametersB.g *
parametersC.g *
parametersD.g *
proto.g *
proto.g~
spines.g *
SynParams.g~
SynParams_D1.g
SynParams_D2.g
SynParamsCtx.g *
SynParamsTh.g *
                            
//spines.g for including spines in the MSN model.

include MScell/AddCaSpines.g

//****************make the spines************************************

function make_spines

float surf_neck, vol_neck, len_neck, dia_neck,dia_head,len_head,dia_head, surf_head,vol_head, shell_thick, dia_shell, shell_head, Ca_tau, kB, kE,r,Ca_base  

//int shellmode                                      
str buffer1 = "spineCa"          // name of the calcium pool in the spine
str buffer2   = "spineCaL"
str buffer3 = "buffer_NMDA"         // only to record NMDA-dependent [Ca]

// parameters:
       // for spine neck:
       len_neck=1e-6                               //0.16-2.13
       dia_neck=0.1e-6                             //(0.038-0.46)e-6
       // for spine head:
       dia_head=0.5e-6                              //adopt common size, no exact data are available now
       len_head=0.5e-6
       surf_head=dia_head*len_head*{PI}
       surf_neck=len_neck*dia_neck*{PI}
       // for calcium shells:
       shell_thick=0.1e-6
       dia_shell= dia_head - shell_thick*2
       shell_head={PI}*(dia_head*dia_head-dia_shell*dia_shell)/4


       kE =86.0                                   // Cater and Sabatini, 2004
       Ca_tau = 25.0e-3                            
       r= (1+kE)/Ca_tau
       Ca_base = 50e-6                            // baseline: 50 nM

//  vol_neck={len_neck*dia_neck*dia_neck*PI/4.0}
  if (!{exists spine})
     create compartment spine
  end

 addfield  spine position
 setfield  spine  \
           Cm     {{CM}*surf_neck} \
           Ra    { 4.0*len_neck*{RA}/(dia_neck*dia_neck*{PI})}  \
           Em     {ELEAK}     \
           initVm {EREST_ACT} \
           Rm     {{RM}/surf_neck} \
           inject  0.0         \
           dia     {dia_neck}       \
           len     {len_neck}    \
           position 0.0   




 create compartment spine/head
 addfield spine/head position
 setfield spine/head          \
         Cm     {{CM}*surf_head} \
         Ra    { 4.0*{RA}*len_head/(dia_head*dia_head*{PI})}  \
         Em     {ELEAK}           \
         initVm {EREST_ACT}       \
         Rm     {{RM}/surf_head} \
         inject  0.0              \
         dia     {dia_head}         \
         len     {len_head}       \
         position 0.0
/*combine neck-head of CA1 CA1_spine */
 addmsg spine/head spine RAXIAL Ra Vm 
 addmsg spine spine/head AXIAL Vm


// make calcium buffers 


str buffer1 = "spineCa"                         // calcium pool for the other calcium channels
str buffer2 = "spineCaL"                        // calcium pool for L-type Ca2+ channels
str buffer3 = "buffer_NMDA"                     // only to record NMDA-dependent [Ca]
	
 if ({shellMode}==0)
         makeCaBuffer {buffer1} spine/head        // to create detailed calcium shells
         copy   spine/head/{buffer1} spine/head/{buffer2}
         copy   spine/head/{buffer1} spine/head/{buffer3} 
     elif ({shellMode}==1)  // Sabatini's model.       Sabatini, 2001,2004
          create Ca_concen  spine/head/{buffer1}  // to create simplified Ca_pool here! 
        if ({CaDyeFlag}==2)
           kB = 220                     // Fluo-4, taken from Yasuda,et,al. 2004,STEK
           Ca_tau = (1+kE+kB)/r         // re-calculate time constant because of application of the new calcium-dye
        elif({CaDyeFlag}==3)
           kB = 70                      // Fluo-5F
           Ca_tau = (1+kE+kB)/r
        end

       
         float  shell_dia= dia_head - shell_thick*2
         float  shell_vol= {PI}*(dia_head*dia_head/4-shell_dia*shell_dia/4)*len_head
          setfield spine/head/{buffer1} \
                                 B          {1.0/(2.0*96494*shell_vol*(1+kE+kB))} \
                                 tau        {Ca_tau}                         \
                                 Ca_base    {Ca_base}   \
                                 thick      {shell_thick} 

        copy   spine/head/{buffer1} spine/head/{buffer2}
        copy   spine/head/{buffer1} spine/head/{buffer3}
        setfield   spine/head/{buffer2}  Ca_base  50e-6
  end 
 
 
	create neutral spine/presyn_ext
	create neutral spine/presyn_inh
 
pushe spine/head

/**************************************************************************************
******************to add NMDA/AMPA channels*******************************************
**************************************************************************************/

addSynChannel . {AMPAname} {AMPAgmax}
addNMDAchannel . {NMDAname} {buffer3} {NMDAgmax} 0 

 	setfield ../presyn_ext z 0
	addmsg   ../presyn_ext  ./{NMDAname} ACTIVATION z
	addmsg   ../presyn_ext  ./{AMPAname} ACTIVATION z
 
 
/**********************************end**********************************************

/// now to add GABA
 setfield ../presyn_inh z 0

 if({GABA2Spine}==1)
       addGABAchannel .  GABA_1  {GABAcond}         // added to spine head 
       addmsg   ../presyn_inh   ./GABA_1 ACTIVATION z 
       addGABAchannel .  GABA_2  {GABAcond}         // added to spine head 
       addmsg   ../presyn_inh   ./GABA_2 ACTIVATION z
 elif({GABA2Spine}==2)
       addGABAchannel  .. GABA_1      {GABAcond}         // added to spine neck
       addmsg   ../presyn_inh   ../GABA_1      ACTIVATION z
       addGABAchannel  .. GABA_2      {GABAcond}         // added to spine neck
       addmsg   ../presyn_inh   ../GABA_2      ACTIVATION z
 end

*/

if({addCa2Spine}==1)
/*************************************************************************************
****************** to add Calcium Channels********************************************
******************* L-type, R-type, and T-type
**************************************************************************************/
//  addCaChannel {obj} {compt} {Gchan} {CalciumBuffer}
float Pbar_CaL12, Pbar_CaL13, Pbar_CaR, Pbar_CaT

 Pbar_CaL12       =      3.35e-7
 Pbar_CaL13       =      4.25e-7
 Pbar_CaR         =     13e-7
 Pbar_CaT         =     0.235e-7

addCaChannelspines CaL12_channel      .  {Pbar_CaL12}    {buffer2}         // HVA CaL
addCaChannelspines CaL13_channel      .  {Pbar_CaL13}    {buffer2}      // LVA CaL
addCaChannelspines CaR_channel        .  {Pbar_CaR}      {buffer1}
addCaChannelspines CaT_channel        .  {Pbar_CaT}      {buffer1}

end


/***************************************************************************************
*********************** to add Na+ channels*********************************************
****************************************************************************************/



pope

end
//******************done making spines*********************************

//*****************begin function to add spines*********************************

function add_spines_evenly(cellpath,spine,a,b,density)
/* "spine"   :   spine prototype
** "density" :   1/um,  spine density; The number of spines in one compartment = density * compartment length. 
*/
 str cellpath,compt,spine,thespine,path
 int number,i
 float dia,len,surf_head,k,dia_dend,len_dend,surf_dend,a,b,density,position

 if(!{exists /library/{spine}})
   echo The spine protomodel has not been made! 
    return
 end

foreach compt ({el {cellpath}/##[TYPE=compartment]}) 
 if (!{{compt}=={{cellpath}@"/axIS"} || {compt}=={{cellpath}@"/ax"}}) 
    dia={getfield {compt} dia}
    position={getfield {compt} position}
     len={getfield {compt} len}
    if ({{getpath {compt} -tail}=="soma"})
              len = dia
    end
  //if the compartment is not a spine ,
  // and its position is between [a,b]
   if ({position>=a} && {position<b} ) 
     number = density * len * 1e6

   // make sure that one compartment has at least one spine
    if (number == 0)
       number = number + 1
    end

  for(i=1;i<=number;i=i+1)
       thespine = "spine"@"_"@{i}
       copy /library/{spine} {compt}/{thespine}
       addmsg {compt}/{thespine} {compt} RAXIAL Ra Vm
       addmsg {compt} {compt}/{thespine} AXIAL Vm
  end

 end // end of if position...

 end // end of if ... axIS



end // end of "foreach" loop

end

Loading data, please wait...