Hippocampus temporo-septal engram shift model (Lytton 1999)

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Accession:7400
Temporo-septal engram shift model of hippocampal memory. The model posits that memories gradually move along the hippocampus from a temporal encoding site to ever more septal sites from which they are recalled. We propose that the sense of time is encoded by the location of the engram along the temporo-septal axis.
Reference:
1 . Lytton WW, Lipton P (1999) Can the hippocampus tell time? The temporo-septal engram shift model. Neuroreport 10:2301-6 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism: Hippocampus;
Cell Type(s):
Channel(s): I Na,t; I K;
Gap Junctions:
Receptor(s): GabaA; AMPA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Pattern Recognition; Temporal Pattern Generation; Spatio-temporal Activity Patterns; Simplified Models;
Implementer(s): Lytton, William [bill.lytton at downstate.edu];
Search NeuronDB for information about:  GabaA; AMPA; I Na,t; I K;
/
lytton99
README
AMPA.mod
GABAA.mod
kdr.mod
matrix.mod *
naf.mod *
passiv.mod *
pulse.mod *
sinstim.mod *
vecst.mod
vecst.mod.orig
bg.inc *
bg_cvode.inc
boxes.hoc *
declist.hoc *
decvec.hoc *
default.hoc *
directory
fig1.gif
grvec.hoc
init.hoc
ivl.vecs
labels.hoc
loadr.hoc *
local.hoc
mosinit.hoc
net.hoc
netcon.inc
nrnoc.hoc
ovl.vecs
params.hoc *
params.hoc.SAV *
proc.hoc
run.hoc
simctrl.hoc *
spkts.hoc
syncode.hoc
tmpl.hoc
                            
// $Id: spkts.hoc,v 1.41 2002/05/14 15:45:08 billl Exp $

// ancillary programs for handling vectors

load_file("decvec.hoc","decvec")
// load_proc("decvec")

//* transfer a file into a list of strings
// usage 'f2slist(list,file)'
proc f2slist() { local i
  $o1.remove_all
  if (! tmpfile.ropen($s2)) { print "Can't open ",$s2
    return }
  while (tmpfile.gets(temp_string_)>0) {
    sfunc.head(temp_string_,"\n",temp_string_) // chop
    tmpobj = new String(temp_string_)
    $o1.append(tmpobj)
  }
}

//* spkts(attrnum[,flag,min,max]) graph spikes from the vectors

thresh = 0    // threshold for deciding which are spikes
burstlen = 1.4  // duration of spike or burst, don't accept another till after this time

proc spkts_call() {}// callback function stub
proc spkts () { local cnt, attrnum, ii, pstep, jj, num, time0, flag, min, max, tst
  vec.resize(0) 
  vec1.resize(0) // will store times and indices respectively
  if (numarg()==0) { print "spkts(attrnum[,flag,min,max])\n\tflag 0: graph, flag 1: save vec1,vec to veclist, flag 2: save inds (vec1) and times (vec)" // infomercial
    return }
  attrnum = $1
  panobj = panobjl.object(attrnum)
  if (attrnum==0) { cnt=printlist.count() } else { cnt = panobj.llist.count() }
  pstep = panobj.printStep
  if (numarg()>1) { flag = $2 } else { flag = 0 }
  if (numarg()>2) { min = $3 } else { min = 0 }
  if (numarg()>3) { max = $4 } else { max = cnt-1 }
  if (flag==0){
    newPlot(0,1,0,1)
    panobj.glist.append(graphItem)
  }
  for ii=min,max {
    if (attrnum==0) { 
      vrtmp.copy(printlist.object(ii).vec) 
      if (panobj.printStep==-2) tvec = printlist.object(ii).tvec
      if (panobj.printStep==-1) tvec = panobj.tvec
    } else {
      rv_readvec(attrnum,ii,vrtmp)  // pick up vector from file
      if (panobj.printStep==-2) tvec = panobj.tvec
    }
    spkts_call()  // place to reset thresh or do other manipulations
    // should replace indvwhere,truncvec with vecst.mod:vec.xing()
    ind.indvwhere(vrtmp,">",thresh) // this has redund points from spk or burst
    if (panobj.printStep<0) { // a tvec
      ind.index(tvec,ind)  // convert indices to times
    } else {
      ind.mul(pstep)  // convert indices to times
    }
    truncvec(ind,vec0,burstlen) // get rid of times too close to previous one
    if (flag==0) { printf("%d:%d ",ii,ind.size()) }  // how many times this cell spiked
    vec0.resize(ind.size)  // scratch vector stores index
    vec0.fill(ii)
    vec1.copy(vec0,vec1.size())  // add same index for each spk to end of vec1
    vec.copy(ind,vec.size())     // add the times for this to end of vec
  }
  
  if (panobj.printStep<0) { // a tvec
    tst = vec.max
  } else {
    tst = pstep*vrtmp.size()         // calc the tst
  }

  if (flag==1) { savevec(vec1) savevec(vec) }
  if (flag<=0) {
    vec1.mark(graphItem,vec,"O",panobj.line)  // graph all the times
    printf("\n")
    graphItem.size(0,tst,min,max)
    graphItem.xaxis(0)
    graphItem.label(0.1,0.9,panobj.filename)
  }
}

//** pull the vec and vec1 files from spkts apart and put in alloc'ed vectors
func parse_spkts () { local p,q
  p=allocvecs(vec1.max+2) q=p+1
  for (ii=0;ii<=vec1.max;ii+=1) {
    mso[p].indvwhere(vec1,"==",ii)
    mso[q].index(vec,mso[p]) 
    q += 1
  }
  return p+1
}

proc line_spkts () { local ii,min,max,xmax,skip
  skip = $1
  if (numarg()==3) { min=$2 max=$3 } else {
    min = int(graphItem.size(3)+1) max = int(graphItem.size(4)) }
  xmax = graphItem.size(2)
  for (ii=min;ii<max;ii=ii+skip) {
    graphItem.beginline()
    graphItem.line(0,ii)
    graphItem.line(xmax,ii)
  }
  graphItem.xaxis()
}

burst_time=0
burst_maxfreq = 30
calc_ave = 0

//** calcspkts(flag,index)
// run after spkts() so vec contains the times, vec1 contains the
// indices
proc calcspkts () { local ii,jj,flag,index,p1,p2,mn,mx
  p1 = allocvecs(2,1000) p2 = p1+1
  if (numarg()==0) {
    print "To be run after spkts(). \
Assumes times in vec, indices in vec1. \
calcspkts(flag,min,max)\nflags:\t1\tspk times\n\t2\tspk freq \
\t3\tburst times\n\t4\tburst freq\nset calc_ave to get averages for freqs"
    return
  }
  // vec contains the times, vec1 contains the indices
  flag = $1
  mn = $2
  if (numarg()==3) { mx=$3 } else { mx=mn }
  for index=mn,mx {
    mso[p2].resize(0)
    mso[p1].indvwhere(vec1,"==",index)
    mso[p1].index(vec,mso[p1])
    if (flag==1) {  
      printf("SPKS for #%d: ",index)
      for jj=0,mso[p1].size()-1 {printf("%g ",mso[p1].x[jj])}
      printf("\n")
    } else if (flag==2) {  
      printf("FREQ for #%d: ",index)
      for jj=0,mso[p1].size()-2 { 
        pushvec(mso[p2],1000./(mso[p1].x[jj+1]-mso[p1].x[jj])) }
      if (calc_ave) { print mso[p2].mean } else { vlk(mso[p2]) }
    } else if (flag==3) {  
      printf("BTIMES for #%d: ",index)
      burst_time = mso[p1].x[0]
      for jj=1,mso[p1].size()-1 {
        if (1000./(mso[p1].x[jj]-burst_time) < burst_maxfreq) {
          printf("%g ",burst_time)
          burst_time = mso[p1].x[jj]
        } 
      }
      printf("\n")
    } else if (flag==4) {  
      printf("BFREQ for #%d: ",index)
      burst_time = mso[p1].x[0]
      for jj=1,mso[p1].size()-1 {
        // should keep track of spike times in case of very long bursts
        if (1000./(mso[p1].x[jj]-burst_time) < burst_maxfreq) {
          pushvec(mso[p2],1000./(mso[p1].x[jj]-burst_time))
          burst_time = mso[p1].x[jj]
        } 
      }
      if (calc_ave) { print mso[p2].mean } else { mso[p2].printf }
    }
  }
  dealloc(p1)
}

func rvwheres () { local ii
  if ($1!=0) {
    for ii=0,panobjl.object($1).llist.count()-1 {
      if (sfunc.substr(panobjl.object($1).llist.object(ii).name,$s2)==0) {
        return ii }
    }
    errorMsg("String not found in rvwheres.")
  }
  return -2
}

supind = 0
//* spkhist assume spk times in vec 
// allows superimposing of graphs
// spkhist(bin_size)
proc spkhist () { local ii,jj,min,max,diff
  if (numarg()==0) { print "spkhist(bin_size)" return }
  if (numarg()==3) { min=$2 max=$3 } else { min=0 max=tstop }
  diff = max-min
  vrtmp.hist(vec,min,max,$1)
  vec0.resize(4*diff/$1)
  vec1.resize(4*diff/$1)
  vec0.fill(0) vec1.fill(0)
  for (ii=min;ii<int(diff/$1);ii=ii+1) {
    jj=ii*4
    vec0.x[jj+0] = ii*$1
    vec0.x[jj+1] = ii*$1
    vec0.x[jj+2] = (ii+1)*$1
    vec0.x[jj+3] = (ii+1)*$1
    vec1.x[jj+0] = 0
    vec1.x[jj+1] = vrtmp.x[ii]
    vec1.x[jj+2] = vrtmp.x[ii]
    vec1.x[jj+3] = 0
  }
  if (panobj.super==0) {
    newPlot(min,max,0,vrtmp.max)
    panobj.glist.append(graphItem)  
  } else { graphItem = panobjl.object(panobj.remote).glist.object(supind) 
    supind = supind+1 }
  vec1.line(graphItem,vec0)
  sprint(temp_string_,"Hist: %s %d",panobj.filename,$1)
  graphItem.label(0.1,0.9,temp_string_)
}

//** truncvec (vec1,vec2,margin) 
// truncate a thresholded time vector so that only one time is given for each spike
// vec1 has thresholded times, vec2 is for scratch use, margin is duration of a spike
proc truncvec () { local ii, num, marg, time0
  marg = $3
  num=0 time0=-10
  $o2.resize($o1.size())
  $o2.fill(-2)
  for ii=0,$o1.size()-1 {
    if ($o1.x[ii] > time0+marg) { 
      $o2.x[ii] = $o1.x[ii]
      time0 = $o1.x[ii]
    }
  }
  $o1.where($o2,">",-1)
}

//** redundout(vec) eliminates sequential redundent entries
// destructive
proc redundout () { local x,ii,p1
  p1=allocvecs(1)
  $o1.sort
  x = $o1.x[0]
  for ii=1,$o1.size-1 {
    if ($o1.x[ii]==x) { $o1.x[ii]=-1e20 } else { x=$o1.x[ii] }
  }
  mso[p1].where($o1,">",-1e20)
  $o1.copy(mso[p1])
  dealloc(p1)
}

//** redundkeep(vec) keeps sequential redundent entries
// destructive
proc redundkeep () { local x,ii
  $o1.sort
  x = $o1.x[0]
  for ii=1,$o1.size-1 {
    if ($o1.x[ii]!=x) { $o1.x[ii-1]=-1e20 x=$o1.x[ii] }
  }
  $o1.where($o1,">",-1e20)
}

//** after running spkall can see which cells are responsible for spks
// assumes spk times in vec, spk identities in vec1
// uses ind and vec0
proc whichspked () { local ii
  ind.indvwhere(vec,"()",$1,$2) // a range
  vec0 = vec1.ind(ind)
  ind = vec.ind(ind)
  for ii=0,ind.size()-1 { printf("%d %g\n",vec0.x[ii],ind.x[ii]) }
}

// firebtwn(ind,time,min,max) list of cells that fire between times min and max
proc firebtwn () { local ii,p1,p2,p3
  p1 = allocvecs(3) p2=p1+1 p3=p2+1
  mso[p3].indvwhere($o2,"[]",$3,$4)
  mso[p1].index($o1,mso[p3]) // indices
  mso[p2].index($o2,mso[p3]) // times
  printf("%d hits\n",mso[p3].size)
  for vtr2(&x,&y,mso[p1],mso[p2]) {
      printf("%4d::%6.2f ",x,y)
      if ((ii+1)%5==0) { print "" }
  }
  print ""
  dealloc(p1)
//  dealloc(p2) // to save the indexes
}

// elimind(ind,time,min,max) take out cells with nums between min,max
// destructive
proc elimind () { local ii,p1
  p1 = allocvecs(1)
  mso[p1].indvwhere($o1,"[]",$3,$4)
  vecelim($o1,mso[p1]) vecelim($o2,mso[p1])
  dealloc(p1)
}

// index/time graph
// tigr(ind,vec,size,marker)
proc tigr () { local sz
  if (numarg()==0) { print "tigr(Yvec,Xvec,marker size,marker type)" 
    print "Marker types: \"o\",t,s,O,T,S,+ (circ, tri, square; CAP is filled)"
    return }
  if (numarg()>2) { sz=$3 } else { sz=6 }
  if (numarg()>3) { temp_string_=$s4 } else { temp_string_="O" }
  nvplt($o2)
  graphItem.size($o2.min,$o2.max,$o1.min,$o1.max)
  $o1.mark(graphItem,$o2,temp_string_,sz,panobj.curcol) 
}

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