Spinal Motor Neuron: Na, K_A, and K_DR currents (Safronov, Vogel 1995)

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Accession:3493
NEURON mod files for the Na, K-A, and K-DR currents from the paper: Safronov, B.V. and Vogel,W. Single voltage-activated Na+ and K+ channels in the somata of rat motorneurons. Journal of Physiology 487.1:91-106 (1995). See the readme.txt file for more information.
Reference:
1 . Safronov BV, Vogel W (1995) Single voltage-activated Na+ and K+ channels in the somata of rat motoneurones. J Physiol 487:91-106 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Channel/Receptor;
Brain Region(s)/Organism:
Cell Type(s): Spinal cord lumbar motor neuron alpha ACh cell;
Channel(s): I Na,t; I A; I K; I Sodium; I Potassium;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Ion Channel Kinetics;
Implementer(s): Migliore, Michele [Michele.Migliore at Yale.edu];
Search NeuronDB for information about:  Spinal cord lumbar motor neuron alpha ACh cell; I Na,t; I A; I K; I Sodium; I Potassium;
load_file("nrngui.hoc")
cvode.active(0)
cvode.atol(1.e-4)
create a
a	{nseg=1 diam=5 L=5 
	insert namot ena=50
	insert pas g_pas=1/10000 Ra=150 cm=1}
access a

celsius=22
tstop=20
vlow=-120
vhigh=20
dt=0.01

mtfac=1
htfac=10

objref gk, b,gt,vc, gs,c, gf,ic
b = new VBox()
c = new VBox()
b.intercept(1)
gk = new Graph(0)
gk.view(vlow,0,vhigh-vlow,1,0,0,100,200)
gk.exec_menu("New Axis")
gk.exec_menu("10% Zoom out")
gk.label(0.1,0.9,"Figs.3C-4B: steady-states")
gk.addexpr("minf_namot",3,2, 2*tstop,0,2)
gk.addexpr("hinf_namot",2,2, 2*tstop,0,2)

gt = new Graph(0)
gt.view(vlow,0,vhigh-vlow,1,0,0,100,200)
gt.exec_menu("New Axis")
gt.exec_menu("10% Zoom out")
gt.label(0.1,0.9,"time constants (scale in ms)")
gt.addexpr("mtau_namot/mtfac",3,2, 2*tstop,0,2)
gt.addexpr("htau_namot/htfac",2,2, 2*tstop,0,2)

xpanel("")
xbutton("run ", "run()")
xpanel()
b.intercept(0)
b.map("Na kinetics for rat motoneuron",100,0,200,400)

c.intercept(1)
gs = new Graph(0)
gs.view(0,-6,tstop,6,0,0,100,200)
gs.exec_menu("New Axis")
gs.exec_menu("10% Zoom out")
gs.label(0.1,0.9,"activation (pA), Fig.3A, step from -120mV")
gs.exec_menu("Keep Lines")

gf = new Graph(0)
gf.view(0,-6,tstop,6,0,0,100,200)
gf.exec_menu("New Axis")
gf.exec_menu("10% Zoom out")
gf.label(0.1,0.9,"inactivation (pA), Fig.4A, step to -30mV ")
gf.exec_menu("Keep Lines")

c.intercept(0)
c.map("activation and inactivation",390,0,500,370)

vc = new SEClamp(0.5)

proc run() {
gk.begin()
for (v=vlow; v<vhigh; v=v+1) {
    trates_namot(v)
    gk.plot(v)
}
gk.flush()
doNotify()

gt.begin()
gt.mark(-50,4.2/htfac,"+",12,6,2)
gt.mark(-40,2.3/htfac,"+",12,6,2)
gt.mark(-30,1.5/htfac,"+",12,6,2)
gt.mark(-20,1.05/htfac,"+",12,6,2)
gt.mark(-10,1/htfac,"+",12,6,2)
gt.mark(0,0.9/htfac,"+",12,6,2)
gt.mark(10,0.8/htfac,"+",12,6,2)
gt.color(2)
gt.label(0.1,0.2,"tau_inact./10")
gt.color(3)
gt.label(0.1,0.7,"tau_act.")
for (v=vlow; v<vhigh; v=v+1) {
    trates_namot(v)
    gt.plot(v)
}
gt.flush()
doNotify()

gbar_namot=0.0003
gs.color(4)
gs.label(0.6,0.25,"-40")
gs.color(1)
gs.label(0.6,0.55,"-10")
gs.color(2)
gs.label(0.6,0.45,"-20")
gs.color(3)
gs.label(0.6,0.35,"-30")
gs.color(5)
gs.label(0.6,0.15,"-50")

gs.begin()
k=-10
color=1
while (k>-60) {
gs.addexpr("ina*area(0.5)*10",color,1, 2*tstop,0,2) // *10=pA, *1e-2=nA
t=0
vc.amp1=-120
vc.dur1=0.2
vc.amp2=k
vc.dur2=tstop
forall {finitialize(vc.amp1)}
while (t<tstop) {
    fadvance()
    gs.plot(t)
    }
gs.flush()
doNotify()
k=k-10
color=color+1
gs.begin()
}

vc.dur1=0
vc.dur2=0
vc.dur3=0

gf.color(4)
gf.label(0.6,0.25,"-100")
gf.color(1)
gf.label(0.6,0.55,"-50")
gf.color(2)
gf.label(0.6,0.45,"-60")
gf.color(3)
gf.label(0.6,0.35,"-80")
gf.color(5)
gf.label(0.6,0.15,"-120")

k=-50
color=1
while (k>=-120) {
gf.addexpr("ina*area(0.5)*10",color,1, 2*tstop,0,2) // *10=pA, *1e-2=nA
t=0
vc.amp1=k
vc.dur1=2
vc.amp2=-30
vc.dur2=tstop
forall {finitialize(k)}
while (t<tstop) {
    fadvance()
    gf.plot(t)
    }
gf.flush()
doNotify()
if (k==-50) {k=k-10} else {k=k-20}
color=color+1
gf.begin()
}
vc.dur1=0
vc.dur2=0
vc.dur3=0
}



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