Conduction in uniform myelinated axons (Moore et al 1978)

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Accession:9851
Examines the relative sensitivity of the velocity of impulse propagation to changes in nodal and internodal parameters.
Reference:
1 . Moore JW, Joyner RW, Brill MH, Waxman SD, Najar-Joa M (1978) Simulations of conduction in uniform myelinated fibers. Relative sensitivity to changes in nodal and internodal parameters. Biophys J 21:147-60 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Axon;
Brain Region(s)/Organism:
Cell Type(s): Myelinated neuron;
Channel(s): I Na,t; I K;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Axonal Action Potentials; Multiple sclerosis;
Implementer(s): Hines, Michael [Michael.Hines at Yale.edu];
Search NeuronDB for information about:  I Na,t; I K;
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moore78
README
cable.hoc
fig2.hoc
fig2.ses
fig3.hoc
fig3.ses
init.hoc
init.ses
mosinit.hoc
                            
load_file("nrngui.hoc")
load_file("init.hoc")

// temperature sensitivity
// (standard temperature is 18.5 degC)

proc q10rates() {
	celsius = $1
}

proc q10axoplasm() { local q10, fac
	q10 = 1.3
	fac = q10^(($1 - 18.5)/10)
	forall Ra = 100 / fac
}

proc q10cond() {local q10, fac
	q10 = 1.4
	fac = q10^(($1 - 0)/10)
	forsec nodes {
		gnabar_hh = 1.2 * fac
		gkbar_hh = .36 * fac
		gl_hh = .003 * fac
	}
}

func fig3vel() {
	if ($2 > 0) {
		q10rates($1)
	}else{
		q10rates(18.5)
	}
	if ($2 > 1) {
		q10axoplasm($1)
	}else{
		q10axoplasm(18.5)
	}
	if ($2 == 3) {
		q10cond($1)
	}else{
		q10cond(0)
	}
	return velocity()
}
		
objref g, min, max
load_file(1, "fig3.ses")
proc pl() {local i, temp, y
	min = new Vector()
	max = new Vector()
	min.append(0,5,5)
	max.append(35,30,30)
	for i=1, 3 {
		g.beginline
		for (temp=min.x[i-1]; temp <= max.x[i-1]; temp += 5) {
			print i, temp
			y = fig3vel(temp, i)
			g.line(temp, log10(y))
			g.flush
		}
	}
}

pl()
print "normal velocity = ", fig3vel(18.5, 0)

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