Simulations of motor unit discharge patterns (Powers et al. 2011)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:143671
" ... To estimate the potential contributions of PIC (Persistent Inward Current) activation and synaptic input patterns to motor unit discharge patterns, we examined the responses of a set of cable motoneuron models to different patterns of excitatory and inhibitory inputs. The models were first tuned to approximate the current- and voltage-clamp responses of low- and medium-threshold spinal motoneurons studied in decerebrate cats and then driven with different patterns of excitatory and inhibitory inputs. The responses of the models to excitatory inputs reproduced a number of features of human motor unit discharge. However, the pattern of rate modulation was strongly influenced by the temporal and spatial pattern of concurrent inhibitory inputs. Thus, even though PIC activation is likely to exert a strong influence on firing rate modulation, PIC activation in combination with different patterns of excitatory and inhibitory synaptic inputs can produce a wide variety of motor unit discharge patterns."
Reference:
1 . Powers RK, Elbasiouny SM, Rymer WZ, Heckman CJ (2012) Contribution of intrinsic properties and synaptic inputs to motoneuron discharge patterns: a simulation study. J Neurophysiol 107:808-23 [PubMed]
Citations  Citation Browser
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):
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Activity Patterns; Bursting; Action Potentials;
Implementer(s): Powers, Randy [rkpowers at u.washington.edu];
Search NeuronDB for information about:  Spinal cord lumbar motor neuron alpha ACh cell;
soma.diam = 53.8888888888889
soma.L = 53.8888888888889
soma.g_pas = 0.00291666666666667
soma.e_pas = -72
soma.gbar_na3rp = 0.044
soma.gbar_naps = 0.00044
soma.sh_na3rp = 5
soma.sh_naps = 15
soma.ar_na3rp = 0.4
soma.ar_naps = 0.4
soma.gMax_kdrRL = 0.07
soma.gcamax_mAHP = 8e-06
soma.gkcamax_mAHP = 0.0076
soma.taur_mAHP = 56.6666666666667
soma.ghbar_gh = 0.000127777777777778
soma.half_gh = -75
is.nseg = 9
is.diam = 3.84444444444444
is.g_pas = 0.001
is.e_pas = -72
is.gbar_na3rp = 0.638888888888889
is.gbar_naps = 0.0127777777777778
is.sh_na3rp = -3
is.sh_naps = 7
is.ar_na3rp = 0.4
is.ar_naps = 0.4
is.gMax_kdrRL = 0.4
axonhillock.nseg = 7
axonhillock.diam(0:1) = 3.84444444444444:12.2222222222222
axonhillock.g_pas = 0.001
axonhillock.e_pas = -72
axonhillock.gbar_na3rp = 0.638888888888889
axonhillock.gbar_naps = 0.0127777777777778
axonhillock.sh_na3rp = -3
axonhillock.sh_naps = 7
axonhillock.ar_na3rp = 0.4
axonhillock.ar_naps = 0.4
axonhillock.gMax_kdrRL = 0.4
dendrite.nseg = 25
dendrite.L = 6422.22222222222
dendrite.diam(0:0.2) = 39.4444444444444:41.4444444444444
dendrite.diam(0.2:1) = 41.4444444444444:0
dendrite.g_pas = 7.22222222222222e-05
dendrite.e_pas = -72
dendrite.gbar_na3rp(0:0.04) = 0.044:0.044
dendrite.gbar_na3rp(0.04:1) = 0.00075:0.00075
dendrite.gbar_naps(0:0.04) = 0.00044:0.00044
dendrite.gbar_naps(0.04:1) = 1.5e-05:1.5e-05
dendrite.sh_na3rp = 5
dendrite.sh_naps = 15
dendrite.ar_na3rp(0:0.04) = 0.4:0.4
dendrite.ar_naps(0:0.04) = 0.4:0.4
dendrite.ar_na3rp(0.04:1) = 0.4:0.4
dendrite.ar_naps(0.04:1) = 0.4:0.4
dendrite.gMax_kdrRL(0:0.04) = 0.08:0.08
dendrite.gMax_kdrRL(0.04:1) = 0.00033:0.00033
dendrite.gcabar_L_Ca(0:0.32) = 0:0
dendrite.gcabar_L_Ca(0.32:0.56) = 0.00016:0.00016
dendrite.gcabar_L_Ca(0.56:1) = 0:0
dendrite.g_kca2(0:0.32) = 0:0
dendrite.g_kca2(0.32:0.56) = 4e-05:4e-05
dendrite.g_kca2(0.56:1) = 0:0
dendrite.depth2_kca2 = 200
dendrite.taur2_kca2 = 120
dendrite.gcamax_mAHP(0:0.04) = 8e-06:8e-06
dendrite.gcamax_mAHP(0.04:1) = 0:0
dendrite.gkcamax_mAHP(0:0.04) = 0.0038:0.0038
dendrite.gkcamax_mAHP(0.04:1) = 0:0
dendrite.taur_mAHP = 56.6666666666667
dendrite.ghbar_gh = 0.000127777777777778
dendrite.half_gh = -75
tmin_kdrRL = 0.8
taumax_kdrRL = 20
qinf_na3rp = 4.8
thinf_na3rp = -50.5
Rd_na3rp = 0.06
qd_na3rp = 1.3
qg_na3rp = 1.3
thi1_na3rp = -35
thi2_na3rp = -35
vslope_naps = 5
celsius = 37
theta_m_L_Ca = -43
V0 = -3.88888888888889