Simulating human single motor units using self-organizing agents

IEEE;IEEE Communications Society;Universite Jean Moulin Lyon 3, Ecole Universitaire de Management;Ecole Nationale Superieure des Mines;UCLB Lyon 12012 IEEE 6th International Conference on Self-Adaptive and Self-Organizing Systems, SASO 2012 -- 10 September 2012 through 14 September 2012 -- Lyon -- 95450Understanding functional synaptic connectivity of human central nervous system is one of the holy grails of the neuroscience. Due to the complexity of nervous system, it is common to reduce the problem to smaller networks such as motor unit pathways. In this sense, we designed and developed a simulation model that learns acting in the same way of human single motor units by using findings on human subjects. The developed model is based on self-organizing agents whose nominal and cooperative behaviors are based on the current knowledge on biological neural networks. The results show that the simulation model generates similar functionality with the observed data. © 2012 IEEE

Is the human masticatory system devoid of recurrent inhibition?

Exp Brain Res. 2007 May;179(1):145-6. Abstract The aim of the present study was to investigate the existence or otherwise of a functional recurrent inhibitory system (Renshaw cell system) in the motoneurons that innervate human masticatory muscles. In a previous study, L: -acetylcarnitine (L: -Ac), a substance known to potentiate recurrent inhibition in humans was found to alter, in a specific way, the discharge variability, and the synchronous activity of motor units depending on the presence or absence of recurrent inhibition in the corresponding motoneuron pool. Using a similar paradigm, we have recorded the tonic discharge activity of motor unit pairs from the masseter muscle during voluntary isometric contraction while subjects were undergoing continuous intravenous saline (SAL, NaCl 0.9%) perfusion. Following a brief baseline-recording period, the subjects were given a test injection of either L: -Ac or isotonic saline (SAL) in a double blind manner. The variability, synchronization, and coherence between the motor unit discharges were analysed during three successive periods: pre-injection, during injection, and post-injection, each lasting 2-3 min. Neither L: -Ac nor SAL injection induced a significant change in the inter-spike interval (ISI) or the coefficient of variation of the ISIs in the motor units tested. There were also no significant changes in the pattern of synchronous activity or in the coherence, which reflects the common frequency content of the unit discharges. Reminiscent of what had been observed previously with motoneurons without recurrent inhibition in the Abductor Digitorum Minimi muscle, the lack of effects of L: -Ac injection on the firing behaviour of masseter motoneurons may suggest that classical Renshaw cell inhibition is lacking in this motoneuron pool