Hyperexcitability from Nav1.2 channel loss in neocortical pyramidal cells (Spratt et al accepted)

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Accession:267067
Based on the Layer 5 thick-tufted pyramidal cell from the Blue Brain Project, we modify the distribution of the sodium channel Nav1.2 to recapitulate an increase in excitability observed in ex vivo slice experiments.
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: Prefrontal cortex (PFC);
Cell Type(s): Neocortex layer 5 pyramidal cell;
Channel(s): I h; I M; I Potassium; I Sodium; I L high threshold; I T low threshold;
Gap Junctions:
Receptor(s):
Gene(s): Nav1.2 SCN2A;
Transmitter(s):
Simulation Environment: NEURON; Python;
Model Concept(s):
Implementer(s): Ben-Shalom, Roy [bens.roy at gmail.com]; Kyoung, Henry [hkyoung at berkeley.edu];
Search NeuronDB for information about:  I L high threshold; I T low threshold; I M; I h; I Sodium; I Potassium;
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SprattEtAl2021
Na12 Analysis
mechanisms
branching.mod *
Ca_HVA.mod *
Ca_LVAst.mod *
CaDynamics_E2.mod *
Ih.mod *
Im.mod *
K_Pst.mod *
K_Tst.mod *
na12.mod
na12_mut.mod
na1216.mod *
na1216_mut.mod *
na16.mod
na8st.mod *
Nap_Et2.mod *
NaTa_t.mod *
NaTs2_t.mod *
nax8st.mod *
ProbAMPANMDA_EMS.mod *
ProbGABAAB_EMS.mod *
SK_E2.mod *
SKv3_1.mod *
vclmp_pl.mod *
26412.tmp *
                            
:Comment : LVA ca channel. Note: mtau is an approximation from the plots
:Reference : :		Avery and Johnston 1996, tau from Randall 1997
:Comment: shifted by -10 mv to correct for junction potential
:Comment: corrected rates using q10 = 2.3, target temperature 34, orginal 21

NEURON	{
	SUFFIX Ca_LVAst
	USEION ca READ eca WRITE ica
	RANGE gCa_LVAstbar, gCa_LVAst, ica
}

UNITS	{
	(S) = (siemens)
	(mV) = (millivolt)
	(mA) = (milliamp)
}

PARAMETER	{
	gCa_LVAstbar = 0.00001 (S/cm2)
}

ASSIGNED	{
	v	(mV)
	eca	(mV)
	ica	(mA/cm2)
	gCa_LVAst	(S/cm2)
	mInf
	mTau
	hInf
	hTau
}

STATE	{
	m
	h
}

BREAKPOINT	{
	SOLVE states METHOD cnexp
	gCa_LVAst = gCa_LVAstbar*m*m*h
	ica = gCa_LVAst*(v-eca)
}

DERIVATIVE states	{
	rates()
	m' = (mInf-m)/mTau
	h' = (hInf-h)/hTau
}

INITIAL{
	rates()
	m = mInf
	h = hInf
}

PROCEDURE rates(){
  LOCAL qt
  qt = 2.3^((34-21)/10)

	UNITSOFF
		v = v + 10
		mInf = 1.0000/(1+ exp((v - -30.000)/-6))
		mTau = (5.0000 + 20.0000/(1+exp((v - -25.000)/5)))/qt
		hInf = 1.0000/(1+ exp((v - -80.000)/6.4))
		hTau = (20.0000 + 50.0000/(1+exp((v - -40.000)/7)))/qt
		v = v - 10
	UNITSON
}