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

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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 GLU 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 GLU 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;
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bpap
CA1_multi
datastore
pars
plots
poirazi-nmda-car
tests
validation-plots
README.txt
ampa_forti.mod
cacum.mod
cad.mod *
cagk.mod
cal.mod
calH.mod
car.mod
car_mag.mod
cat.mod
d3.mod *
h.mod
hha_old.mod
hha2.mod
kadist.mod
kaprox.mod
kca.mod
km.mod
nap.mod
nmda_andr.mod
somacar.mod
binaverages.m
bpap-cell.hoc
bpap-data.hoc
bpap-dendburst.hoc
bpap-graphics.hoc
bpap-gui.hoc
bpap-gui.ses
bpap-pars.hoc
bpap-record.hoc
bpap-run.hoc
bpap-scaling.hoc
bpap-sims.hoc
bpap-sims-cell1.hoc
bpap-sims-cell2.hoc
bpap-sims-scaling.hoc
bpap-somainj.hoc
bpap-spiketrain.hoc
ca1_mrg_cell1.hoc
ca1_mrg_cell2.hoc
ca1_poirazi.hoc
ChannelBlocker.hoc
CrossingFinder.hoc
epspsizes.hoc
figure-example.R
figures.R
figures-common.R
FileUtils.hoc
FormatFile.hoc
ghk.inc
GraphUtils.hoc
Integrator.hoc
Makefile
mosinit.hoc
NmdaAmpaSpineSynStim.hoc
NmdaAmpaSynStim.hoc
ObjectClass.hoc
plotscalingresults_pergroup1.m
plotscalingresults5.m
PointProcessDistributor.hoc
ReferenceAxis.hoc
removezeros.m
RPlot.hoc
scaling_plots.m
Segment.hoc
SimpleSpine.hoc
Spine.hoc
TreePlot.hoc
TreePlotArray.hoc
triexpsyn.inc
units.inc
utils.hoc
validate-bpap.hoc
VarList.hoc
VCaGraph.hoc
                            
TITLE K-A channel from Klee Ficker and Heinemann
: modified by Brannon and Yiota Poirazi (poirazi@LNC.usc.edu)
: to account for Hoffman et al 1997 proximal region kinetics
: used only in soma and sections located < 100 microns from the soma

UNITS {
	  (mA) = (milliamp)
	  (mV) = (millivolt)
    FARADAY = (faraday) (coulomb)
    R = (k-mole) (joule/degC)
}

PARAMETER { :parameters that can be entered when function is called in cell-setup
   	v               (mV)
    ek = -77        (mV) :K reversal potential  (reset in cell-setup.hoc)
  	celsius = 24	  (degC)
   	gkabar = 0      (mho/cm2)           :initialized conductance
    vhalfn = 11     (mV)                :activation half-potential
    vhalfl = -56    (mV)                :inactivation half-potential
    a0n = 0.05      (/ms)               :parameters used
    zetan = -1.5    (1)                 :in calculation of
    zetal = 3       (1)                 :steady state values
    gmn = 0.55      (1)                 :and time constants
    gml = 1         (1)
	  lmin = 2        (ms)
  	nmin = 0.1      (ms)
  	pw = -1         (1)
  	tq = -40        (mV)
  	qq = 5          (mV)
  	q10 = 5                             :temperature sensitivity
}

NEURON {
	  SUFFIX kap
	  USEION k READ ek WRITE ik
    RANGE gkabar,gka, gmax
    GLOBAL ninf,linf,taul,taun,lmin
}

STATE {          :the unknown parameters to be solved in the DEs 
	  n l
}

ASSIGNED {       :parameters needed to solve DE
	  ik   (mA/cm2)
    ninf
    linf      
    taul (ms)
    taun (ms)
    gka  (mho/cm2)
    gmax (mho/cm2)
}

INITIAL {		:initialize the following parameter using rates()
	  rates(v)
	  n = ninf
	  l = linf
	  gka = gkabar*n*l
	  ik = gka*(v-ek)	
    gmax = gka
}

BREAKPOINT {
	  SOLVE states METHOD cnexp
	  gka = gkabar*n*l
	  ik = gka*(v-ek)
    if (gka > gmax) {
        gmax = gka
    }
}

FUNCTION alpn(v(mV)) { LOCAL zeta
    zeta = zetan+pw/(1+exp((v-tq)/qq))
    alpn = exp((1.e-3)*zeta*(v-vhalfn)*FARADAY/(R*(273.16(degC)+celsius))) 
}

FUNCTION betn(v(mV)) { LOCAL zeta
    zeta = zetan+pw/(1+exp((v-tq)/qq))
    betn = exp((1.e-3)*zeta*gmn*(v-vhalfn)*FARADAY/(R*(273.16(degC)+celsius))) 
}

FUNCTION alpl(v(mV)) {
    alpl = exp((1.e-3)*zetal*(v-vhalfl)*FARADAY/(R*(273.16(degC)+celsius))) 
}

FUNCTION betl(v(mV)) {
    betl = exp((1.e-3)*zetal*gml*(v-vhalfl)*FARADAY/(R*(273.16(degC)+celsius))) 
}

:if state_borgka is called from hoc, garbage or segmentation violation will
:result because range variables won't have correct pointer.  This is because
: only BREAKPOINT sets up the correct pointers to range variables.
DERIVATIVE states {     : exact when v held constant; integrates over dt step
    rates(v)
    n' = (ninf - n)/taun
    l' = (linf - l)/taul
}

PROCEDURE rates(v (mV)) {                  :callable from hoc
    LOCAL a,qt
    TABLE ninf, taun, linf, taul  DEPEND celsius, vhalfn, vhalfl, a0n, zetan,  zetal, gmn, gml, lmin, nmin,	pw,	tq,	qq,	q10 FROM -100 TO 100 WITH 200
    qt = q10^((celsius-24(degC))/10(degC))         : temprature adjastment factor
    a = alpn(v)
    ninf = 1/(1 + a)                   : activation variable steady state value
    taun = betn(v)/(qt*a0n*(1+a))      : activation variable time constant
	  if (taun<nmin) {taun=nmin}         : time constant not allowed to be less than nmin
    a = alpl(v)
    linf = 1/(1+ a)                    : inactivation variable steady state value
	  taul = 0.26(ms/mV)*(v+50(mV))                 : inactivation variable time constant
	  if (taul<lmin) {taul=lmin}         : time constant not allowed to be less than lmin
}

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