CA3 pyramidal neuron: firing properties (Hemond et al. 2008)

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Accession:101629
In the paper, this model was used to identify how relative differences in K+ conductances, specifically KC, KM, & KD, between cells contribute to the different characteristics of the three types of firing patterns observed experimentally.
Reference:
1 . Hemond P, Epstein D, Boley A, Migliore M, Ascoli GA, Jaffe DB (2008) Distinct classes of pyramidal cells exhibit mutually exclusive firing patterns in hippocampal area CA3b. Hippocampus 18:411-24 [PubMed]
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Model Information (Click on a link to find other models with that property)
Model Type: Dendrite;
Brain Region(s)/Organism:
Cell Type(s): Hippocampus CA3 pyramidal cell;
Channel(s): I Na,t; I L high threshold; I T low threshold; I A; I K; I M; I h; I K,Ca; I CAN; I Calcium; I Potassium;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Bursting; Active Dendrites; Detailed Neuronal Models; Action Potentials;
Implementer(s): Migliore, Michele [Michele.Migliore at Yale.edu];
Search NeuronDB for information about:  Hippocampus CA3 pyramidal cell; I Na,t; I L high threshold; I T low threshold; I A; I K; I M; I h; I K,Ca; I CAN; I Calcium; I Potassium;
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ca3b
readme.html *
cacumm.mod *
cagk.mod *
cal2.mod *
can2.mod *
cat.mod *
distr.mod *
h.mod *
KahpM95.mod *
kaprox.mod *
kd.mod *
kdrca1.mod *
km.mod *
na3n.mod *
naxn.mod *
ca3b-cell1zr.hoc *
ca3b-cell1zr.ses *
fixnseg.hoc *
geo-cell1zr.hoc *
mosinit.hoc *
screenshot.jpg *
                            
TITLE l-calcium channel
: l-type calcium channel


UNITS {
	(mA) = (milliamp)
	(mV) = (millivolt)

	FARADAY = 96520 (coul)
	R = 8.3134 (joule/degC)
	KTOMV = .0853 (mV/degC)
}

PARAMETER {
	v (mV)
	celsius 	(degC)
	gcalbar=.003 (mho/cm2)
	ki=.001 (mM)
	cai = 50.e-6 (mM)
	cao = 2 (mM)
	q10 = 5
	mmin=0.2
	tfa = 1
	a0m =0.1
	zetam = 2
	vhalfm = 4
	gmm=0.1	
	ggk
}


NEURON {
	SUFFIX cal
	USEION ca READ cai,cao WRITE ica
        RANGE gcalbar,cai, ica, gcal, ggk
        GLOBAL minf,tau
}

STATE {
	m
}

ASSIGNED {
	ica (mA/cm2)
        gcal (mho/cm2)
        minf
        tau   (ms)
}

INITIAL {
	rate(v)
	m = minf
}

BREAKPOINT {
	SOLVE state METHOD cnexp
	gcal = gcalbar*m*m*h2(cai)
	ggk=ghk(v,cai,cao)
	ica = gcal*ggk

}

FUNCTION h2(cai(mM)) {
	h2 = ki/(ki+cai)
}


FUNCTION ghk(v(mV), ci(mM), co(mM)) (mV) {
        LOCAL nu,f

        f = KTF(celsius)/2
        nu = v/f
        ghk=-f*(1. - (ci/co)*exp(nu))*efun(nu)
}

FUNCTION KTF(celsius (DegC)) (mV) {
        KTF = ((25./293.15)*(celsius + 273.15))
}


FUNCTION efun(z) {
	if (fabs(z) < 1e-4) {
		efun = 1 - z/2
	}else{
		efun = z/(exp(z) - 1)
	}
}

FUNCTION alp(v(mV)) (1/ms) {
	alp = 15.69*(-1.0*v+81.5)/(exp((-1.0*v+81.5)/10.0)-1.0)
}

FUNCTION bet(v(mV)) (1/ms) {
	bet = 0.29*exp(-v/10.86)
}

FUNCTION alpmt(v(mV)) {
  alpmt = exp(0.0378*zetam*(v-vhalfm)) 
}

FUNCTION betmt(v(mV)) {
  betmt = exp(0.0378*zetam*gmm*(v-vhalfm)) 
}

DERIVATIVE state {  
        rate(v)
        m' = (minf - m)/tau
}

PROCEDURE rate(v (mV)) { :callable from hoc
        LOCAL a, b, qt
        qt=q10^((celsius-25)/10)
        a = alp(v)
        b = 1/((a + bet(v)))
        minf = a*b
	tau = betmt(v)/(qt*a0m*(1+alpmt(v)))
	if (tau<mmin/qt) {tau=mmin/qt}
}