" ... 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."
Model Type: Neuron or other electrically excitable cell
Cell Type(s): Spinal cord lumbar motor neuron alpha ACh cell
Model Concept(s): Activity Patterns; Bursting; Action Potentials
Simulation Environment: NEURON
Implementer(s): Powers, Randy [rkpowers at u.washington.edu]
References:
Powers RK, Elbasiouny SM, Rymer WZ, Heckman CJ. (2012). Contribution of intrinsic properties and synaptic inputs to motoneuron discharge patterns: a simulation study. Journal of neurophysiology. 107 [PubMed]