Double cable myelinated axon (Layer 5 pyramidal neuron; Cohen et al 2020)

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The periaxonal space in myelinated axons is conductive (~50 ohm cm). Together with a rapidly charging myelin sheath and relatively sealed paranodes, periaxonal conduction shapes the saltating voltage profiles of transaxonal (Vm), transmyelin (Vmy) and transfibre (Vmym) potentials. This model exemplifies double cable saltatory conduction across both time and space, and is the same cell (#6) as seen in Movie S4 of Cohen et al. 2020. This model version allows one to visualize and manipulate the controlling parameters of a propagating action potential. Further notes: The corresponding potentials in NEURON to those named above are v, vext (or vext[0]) and v+vext, respectively. The loaded biophysical parameters were those optimized for this cell (Cohen et al. 2020).
1 . Cohen CCH, Popovic MA, Klooster J, Weil M, Möbius W, Nave K, Kole MHP (2020) Saltatory Conduction along Myelinated Axons Involves a Periaxonal Nanocircuit Cell
Model Information (Click on a link to find other models with that property)
Model Type: Axon; Channel/Receptor; Dendrite; Extracellular; Glia; Neuron or other electrically excitable cell;
Brain Region(s)/Organism:
Cell Type(s): Neocortex L5/6 pyramidal GLU cell; Myelinated neuron;
Channel(s): Ca pump; I Calcium; I h; I K,Ca; I K,leak; I L high threshold; I T low threshold; I M; I Na,p; I Na,t; I Sodium; I Potassium;
Gap Junctions:
Simulation Environment: NEURON;
Model Concept(s): Action Potentials; Active Dendrites; Axonal Action Potentials; Conductance distributions; Conductances estimation; Detailed Neuronal Models; Electrotonus; Extracellular Fields; Membrane Properties; Multiple sclerosis; Parameter sensitivity; Double cable;
Implementer(s): Cohen, Charles CH [c.cohen at]; Kole, Maarten [m.kole at];
Search NeuronDB for information about:  Neocortex L5/6 pyramidal GLU cell; I Na,p; I Na,t; I L high threshold; I T low threshold; I K,leak; I M; I h; I K,Ca; I Sodium; I Calcium; I Potassium; Ca pump;
// nFit
// (c) Charles CH Cohen, 2014-present
// this software is released to the public under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 
// International license (CC BY-NC-ND 4.0, in English).
// for any questions, please email

// ------------------------------Directories---------------------------------------
strdef root
root = getcwd()

strdef lib, ses
strdef cwd
sprint(lib, "%s%s", root, "lib/")
sprint(ses, "%s%s", root, "ses/")
// --------------------------------------------------------------------------------

// -------------------------------Libraries----------------------------------------
loadfile(ses, "morph.hoc")
has_data = getvar(ses, "has_data.dat")
// --------------------------------------------------------------------------------

print "\nReset Mode to Active or Passive"

mode = getvar(ses, "mode.dat")

strdef modeqstr, sesqstr
modeqstr = "\nEnter 0 for changing to Passive, 1 for Active [0/1]"

if (mode == 0) {

	print "\nCurrent mode = Passive (0)"
	ans = xred(modeqstr, 1, 0, 1)

	if (ans == 0) {

		print "Mode unchanged"
	} else if (ans == 1) {

		print "\nChanging mode to Active...\n"
		mode = 1
		writebit(ses, "mode.dat", mode)
		print "Mode changed to Active"

} else if (mode == 1) {

	print "\nCurrent mode = Active (1)"
	ans = xred(modeqstr, 0, 0, 1)

	if (ans == 1) {

		print "Mode unchanged"

	} else if (ans == 0) {

		print "\nChanging mode to Passive...\n"
		mode = 0
		writebit(ses, "mode.dat", mode)
		print "Mode changed to Passive"

print "\nPlease confirm starting IClamp:\n"
setfilestr(mode, has_data)
getvec(ses, iampvecfilestr, iampvec)

print "\nYou may now restart the model"

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