title: Sub-threshold spinal cord stimulation facilitates spontaneous motor activity in spinal rats.
abstract: BACKGROUND
  Epidural stimulation of the spinal cord can be used to enable stepping on a treadmill (electrical enabling motor control, eEmc) after a complete mid-thoracic spinal cord transection in adult rats. Herein we have studied the effects of eEmc using a sub-threshold intensity of stimulation combined with spontaneous load-bearing proprioception to facilitate hindlimb stepping and standing during daily cage activity in paralyzed rats.
  
  
  METHODS
  We hypothesized that eEmc combined with spontaneous cage activity would greatly increase the frequency and level of activation of the locomotor circuits in paralyzed rats. Spontaneous cage activity was recorded using a specially designed swivel connector to record EMG signals and an IR based camcorder to record video.
  
  
  CONCLUSIONS
  The spinal rats initially were very lethargic in their cages showing little movement. Without eEmc, the rats remained rather inactive with the torso rarely being elevated from the cage floor. When the rats used their forelimbs to move, the hindlimbs were extended and dragged behind with little or no flexion. In contrast, with eEmc the rats were highly active and the hindlimbs showed robust alternating flexion and extension resulting in step-like movements during forelimb-facilitated locomotion and often would stand using the sides of the cages as support. The mean and summed integrated EMG levels in both a hindlimb flexor and extensor muscle were higher with than without eEmc. These data suggest that eEmc, in combination with the associated proprioceptive input, can modulate the spinal networks to significantly amplify the amount and robustness of spontaneous motor activity in paralyzed rats.
authors.forename: Parag
authors.initials: P
authors.lastname: Gad
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Choe
authors.forename: Prithvi
authors.initials: P
authors.lastname: Shah
authors.forename: Guillermo
authors.initials: G
authors.lastname: Garcia-Alias
authors.forename: Mrinal
authors.initials: M
authors.lastname: Rath
authors.forename: Yury
authors.initials: Y
authors.lastname: Gerasimenko
authors.forename: Hui
authors.initials: H
authors.lastname: Zhong
authors.forename: Roland R
authors.initials: RR
authors.lastname: Roy
authors.affiliation: Department of Integrative Biology and Physiology, University of California, Los Angeles, Terasaki Life Sciences Building, 610 Charles E, Young Drive East, Los Angeles, CA 90095-7239, USA. vre@ucla.edu.
authors.forename: Victor Reggie
authors.initials: VR
authors.lastname: Edgerton
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004567:Electrodes, Implanted; D004576:Electromyography; D005260:Female; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D062187:Spinal Cord Stimulation / Q000379:methods*