The Circuitry of the Human Spinal Cord

Simulation system of spinal cord motor nuclei and associated nerves and muscles, in a Web-based architecture

“…These curves were obtained by applying increasing amplitude pulses over the simulated PTN and measuring the soleus peak-to-peak H reflex and M wave responses. These recruitment curves are within a range found experimentally Pierrot-Deseilligny and Burke 2005) and unpublished data supplied by M. K. Floeter and A. F. Kohn.…”

“…The simulations of the H-reflex and other electrophysiological protocols, such as those involving reflex-conditioning by antagonist Ia and homonymous Ib electrical activation (Pierrot-Deseilligny and Burke 2005), are capable of providing several measurements not available from the non-invasive human experiments. For example, it is possible to characterize all motoneurons' discharge patterns in different experimental situations, which are not known experimentally.…”

“…Another direction is the inclusion of a more complete representation of the interneuronal network of the spinal cord that acts on the different motoneuron pools (Jankowska 1992;Bashor 1998;Pierrot-Deseilligny and Burke 2005).…”

“…Experiments conducted in our laboratory, as well as those published in the literature Kohn et al 1997;Pierrot-Deseilligny and Burke 2005), supplied data used to adjust the threshold for axon firing and the size of motor-unit potentials (MUAP). These parameters were changed in an ad-hoc way (within physiological ranges) until the simulated motor nuclei could generate H-reflexes compatible with those obtained in humans.…”

“…The former transmit proprioceptive and cutaneous information from the muscles and the body to the spinal cord neuronal circuitry, while the latter drive the motoneurons and interneurons. Reviews on spinal cord circuitry may be found in Burke (2004) and PierrotDeseilligny and Burke (2005).…”