TITLE Second Sodium transient current for Traub RD et al 2005

COMMENT
	This sodium current was present in Gabaergic interneurons and spiny stellate
	cells in the Traub et al 2005 model: deepaxax, deepbask, deepLTS, spinstell,
	supaxax, supbask, supLTS, nRT
	Tom Morse 3/8/2006
	Modified from the
	Implementation of naf by Maciej Lazarewicz 2003 (mlazarew@seas.upenn.edu)
	made for RD Traub, J Neurophysiol 89:909-921, 2003
ENDCOMMENT

INDEPENDENT { t FROM 0 TO 1 WITH 1 (ms) }

UNITS { 
	(mV) = (millivolt) 
	(mA) = (milliamp) 
} 
NEURON { 
	SUFFIX naf2
	USEION na READ ena WRITE ina
	RANGE gbar, ina,m, h, df, fastNa_shift, a, b, c, d, minf, mtau
}
PARAMETER { 
	fastNa_shift = -3.5 (mV): 0 : orig -3.5 (mV)
	a = 0 (1)
	b = 0 (1)
	c = 0 (1)
	d = 0 (1)
	gbar = 0.0 	   (mho/cm2)
	v (mV) ena 		   (mV)  
} 
ASSIGNED { 
	ina 		   (mA/cm2) 
	minf hinf 	   (1)
	mtau (ms) htau 	   (ms)
	df	(mV)
} 
STATE {
	m h
}
BREAKPOINT { 
	SOLVE states METHOD cnexp
	ina = gbar * m * m * m * h * ( v - ena ) 
	df = v - ena
} 
INITIAL { 
	settables( v )
	m = minf
	m = 0
	h  = hinf
} 
DERIVATIVE states { 
	settables( v ) 
	m' = ( minf - m ) / mtau 
	h' = ( hinf - h ) / htau
}

UNITSOFF 

PROCEDURE settables(v1(mV)) {

	TABLE minf, hinf, mtau, htau  FROM -120 TO 40 WITH 641

	minf  = 1 / ( 1 + exp( ( - ( v1 + fastNa_shift ) - 38 ) / 10 ) )
	if( ( v1 + fastNa_shift ) < -30.0 ) {
		mtau = 0.0125 + 0.1525 * exp( ( ( v1 + fastNa_shift ) + 30 ) / 10 )
	} else{
		mtau = 0.02 + a + (0.145+ b) * exp( ( - ( v1 + fastNa_shift +d ) - 30 ) / (10+c) ) 
	}

	: hinf, and htau are shifted 3.5 mV comparing to the paper

	hinf  = 1 / ( 1 + exp( ( ( v1 + fastNa_shift * 0 ) + 58.3 ) / 6.7 ) )
	htau = 0.225 + 1.125 / ( 1 + exp( ( ( v1 + fastNa_shift * 0 ) + 37 ) / 15 ) )
}

UNITSON