Models of Na channels from a paper on the PKC control of I Na,P (Baker 2005)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:85112
"The tetrodotoxin-resistant (TTX-r) persistent Na(+) current, attributed to Na(V)1.9, was recorded in small (< 25 mum apparent diameter) dorsal root ganglion (DRG) neurones cultured from P21 rats and from adult wild-type and Na(V)1.8 null mice. ... Numerical simulation of the up-regulation qualitatively reproduced changes in sensory neurone firing properties. ..." Note: models of NaV1.8 and NaV1.9 and also persistent and transient Na channels that collectively model Nav 1.1, 1.6, and 1.7 are present in this model.
Reference:
1 . Baker MD (2005) Protein kinase C mediates up-regulation of tetrodotoxin-resistant, persistent Na+ current in rat and mouse sensory neurones. J Physiol 567:851-67 [PubMed]
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): Dorsal Root Ganglion (DRG) cell;
Channel(s): I Na,p; I Na,t; I K;
Gap Junctions:
Receptor(s):
Gene(s): Nav1.1 SCN1A; Nav1.6 SCN8A; Nav1.7 SCN9A; Nav1.8 SCN10A; Nav1.9 SCN11A SCN12A;
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Ion Channel Kinetics; Action Potentials; Signaling pathways; Nociception;
Implementer(s): Morse, Tom [Tom.Morse at Yale.edu];
Search NeuronDB for information about:  I Na,p; I Na,t; I K;
Files displayed below are from the implementation
// fig8.hoc
// recreate fig 8 from Baker '05
// Tom Morse 3/5/07

objref volt_vec, time_vec, current_vec, inav1p8_vec, ikf_vec

{volt_vec = new Vector()}
{time_vec = new Vector()}
{current_vec = new Vector()}
{inav1p8_vec = new Vector()}
{ikf_vec = new Vector()}

volt_vec.record(&soma.v(0.5))
time_vec.record(&t)

inav1p8_vec.record(&soma.i_nav1p8(0.5))
ikf_vec.record(&soma.i_kf(0.5))

objref sec
soma sec=new SEClamp(0.5) // Single Electrode Clamp used for Voltage Clamp

// figure 8A

// reduce K currents to 1/10th size to mimic effect of blockers
gbar_ks *= 0.1
gbar_kf *= 0.1

// adjust sodium reversal potential to reflect 1/3rd gradient (personal comm. Baker)
ena_nav1p8 = 37

sec.rs=1e-3 // MOhm small resistance causes cell to faithfully follow volt command

sec.amp1=-110
sec.dur1=5

sec.amp2=-50
sec.dur2=45

sec.amp3=-110
sec.dur3=5

tstop=sec.dur1 + sec.dur2 + sec.dur3  // run for at least as long as SEClamp

objref fig8A_top, fig8A_bottom
fig8A_top = new Graph()
fig8A_bottom = new Graph()

volt_graph.exec_menu("Erase")
volt_graph.exec_menu("Keep Lines")

v_init=-110 // when init() is called the membrane v is set to v_init
cntr=1
proc fig8() {
	for (level=-50; level<=70; level += 10) {
	
		init()
		sec.amp2=level
		run()
	
		inav1p8_vec.line(fig8A_top, time_vec)
		current_vec = inav1p8_vec.add(ikf_vec)
		current_vec.line(fig8A_bottom, time_vec)
	print cntr
	cntr += 1
	}
	fig8A_top.exec_menu("View = plot")
	fig8A_bottom.exec_menu("View = plot")
}

fig8()
volt_graph.exec_menu("View = plot")

Loading data, please wait...