CA1 pyramidal neuron: synaptically-induced bAP predicts synapse location (Sterratt et al. 2012)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:144490
This is an adaptation of Poirazi et al.'s (2003) CA1 model that is used to measure BAP-induced voltage and calcium signals in spines after simulated Schaffer collateral synapse stimulation. In the model, the peak calcium concentration is highly correlated with soma-synapse distance under a number of physiologically-realistic suprathreshold stimulation regimes and for a range of dendritic morphologies. There are also simulations demonstrating that peak calcium can be used to set up a synaptic democracy in a homeostatic manner, whereby synapses regulate their synaptic strength on the basis of the difference between peak calcium and a uniform target value.
Reference:
1 . Sterratt DC, Groen MR, Meredith RM, van Ooyen A (2012) Spine calcium transients induced by synaptically-evoked action potentials can predict synapse location and establish synaptic democracy. PLoS Comput Biol 8:e1002545 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell;
Brain Region(s)/Organism:
Cell Type(s): Hippocampus CA1 pyramidal cell;
Channel(s): I Na,t; I L high threshold; I T low threshold; I A; I K; I M; I Mixed; I R; I_AHP;
Gap Junctions:
Receptor(s): AMPA; NMDA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Dendritic Action Potentials; Synaptic Plasticity;
Implementer(s): Sterratt, David ; Groen, Martine R [martine.groen at gmail.com];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal cell; AMPA; NMDA; I Na,t; I L high threshold; I T low threshold; I A; I K; I M; I Mixed; I R; I_AHP;
/
bpap
CA1_multi
lib
basic_graphics.hoc *
basic-graphics.hoc *
choose-secs.hoc *
current-balance.hoc *
cut-sections.hoc *
deduce-ratio.hoc *
find-gmax.hoc *
GABA_shiftsyn.hoc *
GABA_shiftsyn_bg.hoc *
ken.h *
map-segments-to-3d.hoc *
maxmin.hoc *
newshiftsyn.exe *
num-rec.h *
salloc.hoc *
shiftsyn-init_bg.hoc *
shiftsyn-initA.hoc *
spikecount.hoc *
tune-epsps.hoc *
vector-distance.hoc *
verbose-system.hoc *
                            
// Given a reference point (ie, soma), an apex point, and a point of
// interest, (POI), this function returns the distance from the reference point to
// the POI. These three points are vectors with x,y,z as their values
// written by Terrence Brannon, last modified by Yiota Poirazi, July 2001, poirazi@LNC.usc.edu

objref RP, POI, APEX

proc pvec() {
  printf("%s: \t", $s1)
  $o2.printf("%f ")
}

proc pvecs() {
  pvec("RP", RP)
  pvec("APEX",APEX)
  pvec("POI",POI)
}

proc clear_vecs() {
  RP=new Vector()
  APEX=new Vector()
  POI=new Vector()
}

objref vhold
vhold=new Vector()

func vector_distance() { local adjustment
//  print "func vector_distance() {"

  clear_vecs()
  
  RP=$o1.c
  APEX=$o2.c
  POI=$o3.c
  adjustment = $4

//  pvecs()

  // Subtract Psoma: Qapex = Papex - Psoma. Therefore Qsoma=0,0,0

  APEX.sub(RP)
  POI.sub(RP)
    RP.sub(RP)

//    pvecs()

  // Normalize Qapex, Creating Uapex

  vhold=APEX.c
  vhold.mul(vhold)
  APEX_BAR=sqrt(vhold.sum())

//  printf("APEX_BAR: %f\n", APEX_BAR)

  APEX.div(APEX_BAR)

//  pvec("UAPEX", APEX)

  // Find length of projection of Qdend onto Uapex

  H = POI.dot(APEX) + adjustment
  
  H=abs(H)

  return(H)
}

objref fvd_vec
strdef fvd_str
func find_vector_distance() {

  fvd_vec=new Vector()
  sprint(fvd_str, "access %s", $s1)
  execute1(fvd_str)
  
  vcreate2(fvd_vec,0)
  
  return(vector_distance(vRP,vAPEX,fvd_vec,adjustment))
}

func find_vector_distance_precise() {

  fvd_vec=new Vector()
  sprint(fvd_str, "access %s", $s1)
  execute1(fvd_str)
  
  vcreate3(fvd_vec,$2)
  
  return(vector_distance(vRP,vAPEX,fvd_vec,adjustment))
}

proc vcreate() {
  $o1.append(x3d(0))
  $o1.append(y3d(0))
  $o1.append(z3d(0))
}

proc vcreate2() {
  $o1.append(x3d($2))
  $o1.append(y3d($2))
  $o1.append(z3d($2))
}

proc vcreate3() {
  $o1.append(x_d3($2))
  $o1.append(y_d3($2))
  $o1.append(z_d3($2))
}

Loading data, please wait...