Computer model of clonazepam`s effect in thalamic slice (Lytton 1997)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:12631
Demonstration of the effect of a minor pharmacological synaptic change at the network level. Clonazepam, a benzodiazepine, enhances inhibition but is paradoxically useful for certain types of seizures. This simulation shows how inhibition of inhibitory cells (the RE cells) produces this counter-intuitive effect.
Reference:
1 . Lytton WW (1997) Computer model of clonazepam's effect in thalamic slice. Neuroreport 8:3339-43 [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 Na,t; I T low threshold; I K; I CAN;
Gap Junctions:
Receptor(s): GabaA; Gaba;
Gene(s):
Transmitter(s): Gaba;
Simulation Environment: NEURON;
Model Concept(s): Activity Patterns; Bursting; Therapeutics; Epilepsy; Calcium dynamics;
Implementer(s): Lytton, William [billl at neurosim.downstate.edu];
Search NeuronDB for information about:  Thalamus geniculate nucleus (lateral) principal neuron; Thalamus reticular nucleus cell; GabaA; Gaba; I Na,t; I T low threshold; I K; I CAN; Gaba;
/
lytton97b
README
AMPA.mod
calciumpump_destexhe.mod *
GABAA.mod
GABAB1.mod
GABALOW.mod
HH_traub.mod *
IAHP_destexhe.mod
ICAN_destexhe.mod
ICAN_voltdep.mod
Ih_old.mod *
IT_wang.mod
IT2_huguenard.mod
NMDA.mod
passiv.mod *
pregen.mod *
presyn.mod *
pulse.mod
rand.mod
bg.inc *
boxes.hoc
ctl.dat
ctlnew.dat
czp.dat
czpnew.dat
declist.hoc *
decvec.hoc *
default.hoc *
disp.hoc
Fig3.gif
Fig4.gif
geom.hoc
grvec.hoc
init.hoc
labels.hoc
local.hoc
mod_func.c
mosinit.hoc
network.hoc
neurrep8
nrnoc.hoc
params.hoc
presyn.inc *
queue.inc *
run.hoc
show.hoc
simctrl.hoc *
sns.inc *
snsarr.inc
snscode.hoc
snsgr.hoc
snshead.inc *
synq.inc *
xtmp
                            
// $Id: snsgr.hoc,v 1.15 1995/11/20 02:25:02 billl Exp $

//* GRAPHICAL DISPLAY OF CONNECTIVITY

objref snsgrlist // a list of connectivity graphs
snsgrlist = new List()
objectvar ind, vec
ind = new Vector(100)
vec = new Vector(100)

symnum = 7
colnum = 8
objectvar cl[colnum], sym[symnum] // only 9 different symbols available
for tempvar=0,symnum-1 { sym[tempvar]=new String() }
for tempvar=0,colnum-1 { cl[tempvar]=new String()} 

{ cl[0].s ="black"  cl[1].s ="red"  cl[2].s ="blue"  cl[3].s ="green"  cl[4].s ="orange"
  cl[5].s ="brown"  cl[6].s ="violet"  cl[7].s ="yellow"  }

{ sym[0].s = "o" sym[1].s = "t" sym[2].s = "s"  
  sym[3].s = "O" sym[4].s = "T" sym[5].s = "S"  sym[6].s = "+"}

offnum = 6
offint = 0.15

//** verge(LIST) shows divergence or convergence for syn mechs in LIST
proc verge () { local i,cnt,dotsize
  if (numarg()>1) { dotsize = $2 } else { dotsize = 2 }
  cnt = $o1.count()
  vec.resize(cnt)
  for (i=0;i<cnt;i=i+1) {
    vec.set(i,$o1.object(i).check)
  }
  graphItem = new Graph()
  graphItem.save_name("snsgrlist.")
  snsgrlist.append(graphItem)
  graphItem.size(0,cnt,-1,vec.max)
  vec.mark(graphItem,1,"o",dotsize)
  graphItem.xaxis()
}

//** connmat(LIST,XCODEWORD,XFIELD,YCODEWORD,YFIELD,[DOTSIZE,SYMBOLS,OFFSET,LABEL])
// shows connectivity matrix
// eg connmat(prelist,"pre",3,"post",4)
proc connmat () { local i, j, k, nsyn, xnum, ynum, ymin,\
                        cdx, cdy, cdd, cde, dotsize, abc, inc, color
  if (numarg()==0) {
    print "connmat(LIST,XCODEWORD,XFIELD,YCODEWORD,YFIELD,[DOTSIZE,SYMBOLS,OFFSET,LABEL])"
    print "  colors: black, red, blu, green, orange, brown, violet, yellow"
    print "  characters: o,t,s,O,T,S,+ (circ, tri, square; CAP is filled)"
    return
  }
  if (numarg()==1) {
    if (sfunc.len(mechnames) > 0) {
      sprint(temp_string_,"/%d/",$1)
      sfunc.tail(mechnames,temp_string_,temp_string_)
      sfunc.head(temp_string_,"/",temp_string_)
      print temp_string_
    } else if($1<tmplist.count) { print tmplist.object($1) }
    printf("%s %s; xoff=%g, yoff=%g\n", \
           cl[$1%colnum].s,sym[$1%symnum].s,offint*int($1/offnum),offint*($1%offnum))
    return
  }
  if (numarg()>5) { dotsize = $6 } else { dotsize = 2 }
  if (numarg()>6) { abc = $7 } else {abc = 0}
  if (numarg()>7) { offint = $8 } else {offint = 0.15}
  inc = xnum = ynum = ymin = 0
  if ((cdx = connmat_findstr($s2)) == -1) { print "unknown x string" return }
  if ((cdy = connmat_findstr($s4)) == -1) { print "unknown y string" return }
  graphItem = new Graph()
  if (numarg()>8) { graphItem.label($s9) }
  graphItem.save_name("snsgrlist.")
  sprint(temp_string_,"%s %s%d %s%d",$o1,$s2,$3,$s4,$5)
  graphItem.label(temp_string_)
  snsgrlist.append(graphItem)
  print "chose/total"
  for i=0,$o1.count-1 {
    nsyn = $o1.object(i).nsyn
    ind.resize(nsyn)
    ind.fill(-1)
    vec.resize(nsyn)
    vec.fill(-1)
    k = 0
    for j=0,nsyn-1 {
      if (cmcb($o1.object(i),j)==1) {
        k = k + 1
        cdd = connmat_newpt($o1.object(i),cdx,$3,j,i) + offint*int(inc/offnum)
        cde = connmat_newpt($o1.object(i),cdy,$5,j,i) + offint*(inc%offnum)
        if (cdd < 0 || cde < 0) {
          continue
        }
        if (cdd > xnum) xnum = cdd
        if (cde > ynum) ynum = cde
        if (cde < ymin) ymin = cde
        ind.set(j,cdd)
        vec.set(j,cde)  // put in the duplicates so fill vector (else stray 0s)
      }
    }
    printf("%d: %d/%d ",i,k,nsyn)
    if (abc) {
      color = i%8 + 1  // only 8 useable colors; 0 is white
      vec.mark(graphItem,ind,sym[i%symnum].s,dotsize,color,3)
    } else {
      vec.mark(graphItem,ind,"o",dotsize)
    }
    inc = inc + 1
  }
  printf("\n")
  for (ii=1;ii<ynum;ii=ii+1) {
    graphItem.beginline()
    graphItem.line(0,ii)
    graphItem.line(xnum,ii)
  }
//  graphItem.size(0,xnum,ymin,ynum) // -1 means not set, -2 means empty pointer
  graphItem.size(0,100,0,100) // -1 means not set, -2 means empty pointer
  graphItem.xaxis()
}

// stub callback function
// called with object ($o1) and nsyn ($2)
// can call connmat_newpt if want to check something
// eg if (connmat_newpt($o1,2,1,$2) != 2) { return 0 }
//  would check field 1 of post and not permit graphing if != 2
func cmcb () { return 1 }

Loading data, please wait...