Complex CA1-neuron to study AP initiation (Wimmer et al. 2010)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:123927
Complex model of a pyramidal CA1-neuron, adapted from Royeck, M., et al. Role of axonal NaV1.6 sodium channels in action potential initiation of CA1 pyramidal neurons. Journal of neurophysiology 100, 2361-2380 (2008). It contains a biophysically realistic morphology comprising 265 compartments (829 segments) and 15 different distributed Ca2+- and/or voltage-dependent conductances.
Reference:
1 . Wimmer VC, Reid CA, Mitchell S, Richards KL, Scaf BB, Leaw BT, Hill EL, Royeck M, Horstmann MT, Cromer BA, Davies PJ, Xu R, Lerche H, Berkovic SF, Beck H, Petrou S (2010) Axon initial segment dysfunction in a mouse model of genetic epilepsy with febrile seizures plus. J Clin Invest 120:2661-71 [PubMed]
Citations  Citation Browser
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,p; I Na,t; I L high threshold; I N; I T low threshold; I p,q; I A; I K; I K,leak; I M; I h; I K,Ca; I Calcium;
Gap Junctions:
Receptor(s):
Gene(s): Nav SCN1B;
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Action Potential Initiation; Detailed Neuronal Models; Epilepsy;
Implementer(s): Horstmann, Marie-Therese [mhorstma at uni-bonn.de];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; I Na,p; I Na,t; I L high threshold; I N; I T low threshold; I p,q; I A; I K; I K,leak; I M; I h; I K,Ca; I Calcium;
: from Stacey, Durand 2000
 

UNITS 
{
        (mA) = (milliamp)
        (mV) = (millivolt)
	(S) = (siemens)
	(molar) = (1/liter)
}
 
NEURON {
        SUFFIX KAHP
	USEION k WRITE ik
	USEION ca2 READ ca2i VALENCE 2.0
        RANGE gAHPbar, gAHP
        GLOBAL qinf, qtau
}
 
PARAMETER 
{
        gAHPbar = 0.0033 (S/cm2)	<0,1e9>
        eK = -95 (mV)
    	qtau = 48 (ms)

}
 

STATE 
{
        q
}
 
ASSIGNED 
{
        v (mV)
        celsius (degC)
	gAHP (S/cm2)
        ik (mA/cm2)
	qinf
	ca2i (millimolar)
}
 

BREAKPOINT 
{
        SOLVE states METHOD cnexp
        gAHP = gAHPbar*q
	ik = gAHP*(v - eK)
}
 
 
INITIAL 
{
	rates(v)
	q = qinf
}

DERIVATIVE states 
{  
        rates(v)
 
	q' =  (qinf-q)/qtau
}
 
LOCAL q10


PROCEDURE rates(v(mV))   :Computes rate and other constants at current v.
                      :Call once from HOC to initialize inf at resting v.
{
        LOCAL  alpha, beta, sum

UNITSOFF
               
        q10 = 3^((celsius - 6.3)/10)

        alpha = 0.0048 / exp((10 * log10(ca2i*1000)-35)/-2)
        beta =  0.012 / exp((10 * log10(ca2i*1000)+100) / 5)
        sum = alpha + beta
        qinf = alpha/sum
}
 
FUNCTION vtrap(x,y) {  :Traps for 0 in denominator of rate eqns.
        if (fabs(x/y) < 1e-6) {
                vtrap = y*(1 - x/y/2)
        }else{
                vtrap = x/(exp(x/y) - 1)
        }
}
 
 
UNITSON