Simulation system of spinal cord motor nuclei and associated nerves and muscles,in a Web-based architecture |
| |
Authors: | Rogerio R L Cisi André F Kohn |
| |
Institution: | 1.Biomedical Engineering Laboratory, Escola Politécnica,Universidade de S?o Paulo,S?o Paulo,Brazil |
| |
Abstract: | A Web-based simulation system of the spinal cord circuitry responsible for muscle control is described. The simulator employs
two-compartment motoneuron models for S, FR and FF types, with synaptic inputs acting through conductance variations. Four
motoneuron pools with their associated interneurons are represented in the simulator, with the possibility of inclusion of
more than 2,000 neurons and 2,000,000 synapses. Each motoneuron action potential is followed, after a conduction delay, by
a motor unit potential and a motor unit twitch. The sums of all motor unit potentials and twitches result in the electromyogram
(EMG), and the muscle force, respectively. Inputs to the motoneuron pool come from populations of interneurons (Ia reciprocal
inhibitory interneurons, Ib interneurons, and Renshaw cells) and from stochastic point processes associated with descending
tracts. To simulate human electrophysiological experiments, the simulator incorporates external nerve stimulation with orthodromic
and antidromic propagation. This provides the mechanisms for reflex generation and activation of spinal neuronal circuits
that modulate the activity of another motoneuron pool (e.g., by reciprocal inhibition). The generation of the H-reflex by
the Ia-motoneuron pool system and its modulation by spinal cord interneurons is included in the simulation system. Studies
with the simulator may include the statistics of individual motoneuron or interneuron spike trains or the collective effect
of a motor nucleus on the dynamics of muscle force control. Properties associated with motor-unit recruitment, motor-unit
synchronization, recurrent inhibition and reciprocal inhibition may be investigated. |
| |
Keywords: | Motoneuron Interneuron Renshaw cell Neuronal network Motoneuron pool Muscle Force EMG H-reflex Modeling Simulator |
本文献已被 PubMed SpringerLink 等数据库收录! |
|