Hopfield and Brody model (Hopfield, Brody 2000)

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Accession:2798
NEURON implementation of the Hopfield and Brody model from the papers: JJ Hopfield and CD Brody (2000) JJ Hopfield and CD Brody (2001). Instructions are provided in the below readme.txt file.
References:
1 . Hopfield JJ, Brody CD (2001) What is a moment? Transient synchrony as a collective mechanism for spatiotemporal integration. Proc Natl Acad Sci U S A 98:1282-7 [PubMed]
2 . Hopfield JJ, Brody CD (2000) What is a moment? "Cortical" sensory integration over a brief interval. Proc Natl Acad Sci U S A 97:13919-24 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism: Olfactory cortex;
Cell Type(s):
Channel(s): I Na,t; I A;
Gap Junctions:
Receptor(s): AMPA; Gaba;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Pattern Recognition; Coincidence Detection; Temporal Pattern Generation; Synchronization; Attractor Neural Network; Olfaction;
Implementer(s): Migliore, Michele [Michele.Migliore at Yale.edu];
Search NeuronDB for information about:  AMPA; Gaba; I Na,t; I A;
TITLE na3
: Na current 
: from Jeff M.
:  ---------- modified from na3 
: no slow inactivation -------M.Migliore apr 2001

NEURON {
	SUFFIX nans
	USEION na READ ena WRITE ina
	RANGE  gbar
	GLOBAL minf, hinf, mtau, htau, qinf, thinf
}

PARAMETER {
	gbar = 0.010   	(mho/cm2)	
	ena = 55							
	tha  =  -30	(mV)		: v 1/2 for act	
	qa   = 7.2	(mV)		: act slope (4.5)		
	Ra   = 0.4	(/ms)		: open (v)		
	Rb   = 0.124 	(/ms)		: close (v)		

	thi1  = -45	(mV)		: v 1/2 for inact 	
	thi2  = -45 	(mV)		: v 1/2 for inact 	
	qd   = 1.5	(mV)	        : inact tau slope
	qg   = 1.5      (mV)
	mmin=0.02	
	hmin=0.5			
	q10=2
	Rg   = 0.01 	(/ms)		: inact recov (v) 	
	Rd   = .03 	(/ms)		: inact (v)	
	qq   = 10        (mV)
	tq   = -55      (mV)

	thinf  = -50 	(mV)		: inact inf slope	
	qinf  = 4 	(mV)		: inact inf slope 

        vvh=-58		(mV) 
        vvs=2		(mV)

	v 		(mV)
}


UNITS {
	(mA) = (milliamp)
	(mV) = (millivolt)
	(pS) = (picosiemens)
	(um) = (micron)
} 

ASSIGNED {
	ina 		(mA/cm2)
	thegna		(mho/cm2)
	minf 		hinf 		
	mtau (ms)	htau (ms) 	
}
 

STATE { m h}

BREAKPOINT {
        SOLVE states METHOD cnexp
        thegna = gbar*m*m*m*h
	ina = thegna * (v - ena)
} 

INITIAL {
	trates(v)
	m=minf  
	h=hinf
}

FUNCTION alpv(v(mV)) {
         alpv = 1/(1+exp((v-vvh)/vvs))
}
        
DERIVATIVE states {   
        trates(v)      
        m' = (minf-m)/mtau
        h' = (hinf-h)/htau
}

PROCEDURE trates(vm) {  
        LOCAL  a, b, c, qt
        qt=q10^((celsius-24)/10)
	a = trap0(vm,tha,Ra,qa)
	b = trap0(-vm,-tha,Rb,qa)
	mtau = 1/(a+b)/qt
        if (mtau<mmin) {mtau=mmin}
	minf = a/(a+b)

	a = trap0(vm,thi1,Rd,qd)
	b = trap0(-vm,-thi2,Rg,qg)
	htau =  1/(a+b)/qt
        if (htau<hmin) {htau=hmin}
	hinf = 1/(1+exp((vm-thinf)/qinf))
	c=alpv(vm)
}

FUNCTION trap0(v,th,a,q) {
	if (fabs(v-th) > 1e-6) {
	        trap0 = a * (v - th) / (1 - exp(-(v - th)/q))
	} else {
	        trap0 = a * q
 	}
}	

        


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