Compartmentalization of GABAergic inhibition by dendritic spines (Chiu et al. 2013)

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Accession:143604
A spiny dendrite model supports the hypothesis that only inhibitory inputs on spine heads, not shafts, compartmentalizes inhibition of calcium signals to spine heads as seen in paired inhibition with back-propagating action potential experiments on prefrontal cortex layer 2/3 pyramidal neurons in mouse (Chiu et al. 2013).
Reference:
1 . Chiu CQ, Lur G, Morse TM, Carnevale NT, Ellis-Davies GC, Higley MJ (2013) Compartmentalization of GABAergic inhibition by dendritic spines. Science 340:759-62 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Synapse; Dendrite;
Brain Region(s)/Organism: Neocortex;
Cell Type(s): Neocortex V1 L2/6 pyramidal intratelencephalic cell;
Channel(s): I Na,t; I L high threshold; I K;
Gap Junctions:
Receptor(s): GabaA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Dendritic Action Potentials; Influence of Dendritic Geometry;
Implementer(s): Carnevale, Ted [Ted.Carnevale at Yale.edu]; Morse, Tom [Tom.Morse at Yale.edu];
Search NeuronDB for information about:  Neocortex V1 L2/6 pyramidal intratelencephalic cell; GabaA; I Na,t; I L high threshold; I K;
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singleDendrite
mod
ca.mod
ca_a1g.mod
ca_a1h.mod *
cad.mod
constant.mod
distr.mod *
exp2syncur.mod
exp2synsat.mod
im.mod *
kca.mod *
km.mod *
kv.mod
multiclamp.mod
na.mod
zoidsyn.mod *
                            
COMMENT
  zoidsyn.mod
  Generates a train of symmetrically trapeZoidal conductance changes.
  User specifies trf (duration of rise/fall ramps), tp (duration of plateau),
  start (onset of first trapezoid), interval, i.e. period between 
  trapezoid onsets), and number of trapezoids.
  Error checking in INIT block ensures that interval is longer 
  than trapezoid duration.
  4/1/2012 NTC, minor modifications 4/3/2012 TMM
ENDCOMMENT

NEURON {
  POINT_PROCESS ZoidSyn
  RANGE trf, tp
  RANGE start, interval, number
  RANGE e, gmax, g, i
  NONSPECIFIC_CURRENT i
}

UNITS {
  (mV) = (millivolt)
  (nS) = (nanosiemens)
  (nA) = (nanoamp)
}

PARAMETER {
  trf (ms) <0, 1e9> : duration of rising and falling phases
  tp  (ms) <0, 1e9> : duration of plateau
  start (ms) <0, 1e9> : latency of first transient
  interval (ms) <0, 1e9> : period, i.e. interval between transient onsets
  number : how many to deliver
  e   (mV) : reversal potential
  gmax (nS) <0, 1e9> : conductance during plateau
}

ASSIGNED {
  v (mV)
  i (nA)
  on
  tally : how many more to deliver
  m (1/ms)
  b (1)
  dur (ms) : sum of twice the rise/fall time trp plus tp
  t0 (ms)
  g (nS)
}

INITIAL {
  if (trf <= 0) {
    trf = 1
UNITSOFF
    printf("trf must be longer than 0\n")
    printf("trf has been increased to %g ms\n", trf)
UNITSON
  }
  if (tp < 0) {
    tp = 0
UNITSOFF
    printf("tp must not be negative\n")
    printf("tp has been changed to %g ms\n", tp)
UNITSON
  }
  dur = 2*trf + tp
  if (interval <= dur) {
    interval = dur + 1 (ms)
UNITSOFF
    printf("interval must be longer than trapezoid duration\n")
    printf("interval has been increased to %g ms\n", interval)
UNITSON
  }
  on = 0
  m = 0
  b = 0
  tally = number
  if (tally > 0) {
    net_send(start, 1)
    tally = tally - 1
  }
}

BREAKPOINT {
  g = gmax * (m*(t-t0) + b)
  i = (0.001)*g*(v-e)
}

NET_RECEIVE (w) {
  if ((on == 0) && (flag == 1)) {
    : enter rising phase
    t0 = t
    m = 1/trf
    b = 0
    on = 1
    : prepare for plateau phase
    net_send(trf, 2)
  }
  if (flag == 2) {
    : enter plateau
    m = 0
    b = 1
    : prepare for falling phase
    net_send(tp, 3)
  }
  if (flag == 3) {
    : enter falling phase
    t0 = t
    m = -1/trf
    b = 1
    : prepare to end
    net_send(trf, 4)
  }
  if (flag == 4) {
    : end
    m = 0
    b = 0
    on = 0
    if (tally > 0) {
      : prepare to turn it on again
      net_send(interval - dur, 1)
      tally = tally - 1
    }
  }
}

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