Spinal and Supraspinal Control of the Direction of Stepping during Locomotion
Open Access
- 28 November 2012
- journal article
- research article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 32 (48), 17442-17453
- https://doi.org/10.1523/jneurosci.3757-12.2012
Abstract
Most bipeds and quadrupeds, in addition to forward walking, are also capable of backward and sideward walking. The direction of walking is determined by the direction of stepping movements of individual limbs in relation to the front-to-rear body axis. Our goal was to assess the functional organization of the system controlling the direction of stepping. Experiments were performed on decerebrate cats walking on the treadmill with their hindlimbs, whereas the head and trunk were rigidly fixed. Different directions of the treadmill motion relative to the body axis were used (0, ±45, ±90, and 180°). For each direction, we compared locomotion evoked from the brainstem (by stimulation of the mesencephalic locomotor region, MLR) with locomotion evoked by epidural stimulation of the spinal cord (SC).It was found that SC stimulation evoked well coordinated stepping movements at different treadmill directions. The direction of steps was opposite to the treadmill motion, suggesting that this direction was determined by sensory input from the limb during stance. Thus, SC stimulation activates limb controllers, which are able to generate stepping movements in different directions. By contrast, MLR stimulation evoked well coordinated stepping movements only if the treadmill was moving in the front-to-rear direction. One can conclude that supraspinal commands (caused by MLR stimulation) select one of the numerous forms of operation of the spinal limb controllers, namely, the forward walking. The MLR can thus be considered as a command center for forward locomotion, which is the main form of progression in bipeds and quadrupeds.This publication has 35 references indexed in Scilit:
- Spinal and Supraspinal Control of the Direction of Stepping during LocomotionJournal of Neuroscience, 2012
- Variability in step training enhances locomotor recovery after a spinal cord injuryEuropean Journal of Neuroscience, 2012
- Somatosensory control of balance during locomotion in decerebrated catJournal of Neurophysiology, 2012
- Common muscle synergies for control of center of mass and force in nonstepping and stepping postural behaviorsJournal of Neurophysiology, 2011
- Activity of motor cortex neurons during backward locomotionJournal of Neurophysiology, 2011
- Transformation of nonfunctional spinal circuits into functional states after the loss of brain inputNature Neuroscience, 2009
- Propriospinal Bypass of the Serotonergic System That Can Facilitate SteppingJournal of Neuroscience, 2009
- Maintenance of Lateral Stability During Standing and Walking in the CatJournal of Neurophysiology, 2009
- Characteristics and Mechanisms of Locomotion Induced by Intraspinal Microstimulation and Dorsal Root Stimulation in Spinal CatsJournal of Neurophysiology, 2007
- Postural Control in the Rabbit Maintaining Balance on the Tilting PlatformJournal of Neurophysiology, 2003