Locational influence of dendritic PIC on input-output properties of spinal motoneurons (Kim 2017)

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Accession:239039
How does the dendritic location of calcium persistent inward current (Ca-PIC) influence dendritic excitability and firing behavior across the spinal motoneuron pool? This issue was investigated developing a model motoneuron pool where model parameters were analytically determined to reflect key motoneuron type-specific properties experimentally identified. The simulation results point out the negative relationship between the distance of Ca-PIC source from the soma and cell recruitment threshold as a basis underlying the systematic variation in input-output properties of motoneurons over the motoneuron pool.
References:
1 . Kim H (2017) Impact of the localization of dendritic calcium persistent inward current on the input-output properties of spinal motoneuron pool: a computational study. J Appl Physiol (1985) 123:1166-1187 [PubMed]
2 . Kim H, Jones KE, Heckman CJ (2014) Asymmetry in signal propagation between the soma and dendrites plays a key role in determining dendritic excitability in motoneurons. PLoS One 9:e95454 [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): Spinal cord lumbar motor neuron alpha ACh cell;
Channel(s): I Calcium; I Potassium; I Sodium; I_AHP;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: XPP;
Model Concept(s): Active Dendrites;
Implementer(s): Kim, Hojeong [hojeong.kim03 at gmail.com];
Search NeuronDB for information about:  Spinal cord lumbar motor neuron alpha ACh cell; I Sodium; I Calcium; I Potassium; I_AHP;
# FIG 3A: Is-V properties
# Written by Hojeong Kim

## [dendrite equations] v(mV),t(ms),g(mS/cm^2)
dvd/dt=(ind(vd,dcal)-gmd*(vd-(vl+vrest))+gc*(vs-vd)/(1.0-parea))/cmd
# [inward voltage-gated current]
ind(vd,dcal)=-dgcal*dcal*(vd-(vdcal+vrest))
ddcal/dt=(dcalinf(vd)-dcal)/dcaltau
dcalinf(vd)=1.0/(1.0+exp(-(vd-dcalth)/dcalslp))

## [cable parameters] gms(mS/cm^2),gmd(mS/cm^2),gc(mS/cm^2),cms(uF/cm^2),cmd(uF/cm^2)
p gms=0.143, gmd=0.131, gc=0.211, cms=1.058, cmd=0.915, parea=0.492

## [active parameters]
# resting & reversal potentials
p vna=120.0,vk=-10.0,vl=0.0,vdcal=130.0,vrest=-70
# dendrite
p dgcal=0.124,dcalth=-43.0,dcalslp=6.0,dcaltau=60.0

## [initial conditions]
# dendrites
vd(0)=-70.0
dcal(0)=0.001

## [voltage clamp at the soma]
p vs0=-70,m=40,t_m=10000
vs=vs0+m-(m/t_m)*abs(t-t_m)

## [simulation outputs]: I(nA), V(mV) 
aux Iinj=(gms*(vs-(vl+vrest))+gc*((vs-vd)/parea))*3.16
aux Vclamp=vs

## [simulation environment]
@ maxstor=20000000
@ total=20000
@ method=gear, toler=0.009, dtmax=0.5
@ NPLOT=2, XP=t, YP=Iinj, XP2=t, YP2=Vclamp
@ xlo=0, xhi=20000, ylo=-10, yhi=10
@ bound=10000
@ create=1

done

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