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Sub-threshold spinal cord stimulation facilitates spontaneous motor activity in spinal rats.

Gad P, Choe J, Shah P, Garcia-Alias G, Rath M, Gerasimenko Y, Zhong H, Roy RR, Edgerton VR - J Neuroeng Rehabil (2013)

Bottom Line: Spontaneous cage activity was recorded using a specially designed swivel connector to record EMG signals and an IR based camcorder to record video.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.

View Article: PubMed Central - HTML - PubMed

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.

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.

Results and conclusion: 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.

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Total activity time with and without eEmc. Mean (±SEM, n = 4) duration of spontaneous cage activity during the 6-hr recording period with and without eEmc. *, significantly different from without eEmc at P < 0.05.
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Figure 2: Total activity time with and without eEmc. Mean (±SEM, n = 4) duration of spontaneous cage activity during the 6-hr recording period with and without eEmc. *, significantly different from without eEmc at P < 0.05.

Mentions: The total amount of time that the rats were active during these recordings was ~5-fold higher in the presence compared to the absence of eEmc, i.e., ~2500 sec or ~12% of the time vs. ~500 sec or ~2.5% of the time (Figure 2). The mean integrated EMG (Figure 3B) and summed integrated EMG (Figure 3C) for both the TA and soleus muscles during the 6-hr recording periods of spontaneous cage activity were significantly higher in the presence than in the absence of eEmc. To provide some point of reference regarding these increases in EMG activity with stimulation, the large differences in the mean integrated EMG in both muscles studied with and without eEmc when the rats were stepping on a treadmill are shown (Figure 3A). Furthermore, the amount of activity during the six hours of spontaneous cage activity was equivalent to ~33 minutes of stepping on the treadmill with eEmc compared to ~15 minutes without stimulation.


Sub-threshold spinal cord stimulation facilitates spontaneous motor activity in spinal rats.

Gad P, Choe J, Shah P, Garcia-Alias G, Rath M, Gerasimenko Y, Zhong H, Roy RR, Edgerton VR - J Neuroeng Rehabil (2013)

Total activity time with and without eEmc. Mean (±SEM, n = 4) duration of spontaneous cage activity during the 6-hr recording period with and without eEmc. *, significantly different from without eEmc at P < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016220&req=5

Figure 2: Total activity time with and without eEmc. Mean (±SEM, n = 4) duration of spontaneous cage activity during the 6-hr recording period with and without eEmc. *, significantly different from without eEmc at P < 0.05.
Mentions: The total amount of time that the rats were active during these recordings was ~5-fold higher in the presence compared to the absence of eEmc, i.e., ~2500 sec or ~12% of the time vs. ~500 sec or ~2.5% of the time (Figure 2). The mean integrated EMG (Figure 3B) and summed integrated EMG (Figure 3C) for both the TA and soleus muscles during the 6-hr recording periods of spontaneous cage activity were significantly higher in the presence than in the absence of eEmc. To provide some point of reference regarding these increases in EMG activity with stimulation, the large differences in the mean integrated EMG in both muscles studied with and without eEmc when the rats were stepping on a treadmill are shown (Figure 3A). Furthermore, the amount of activity during the six hours of spontaneous cage activity was equivalent to ~33 minutes of stepping on the treadmill with eEmc compared to ~15 minutes without stimulation.

Bottom Line: Spontaneous cage activity was recorded using a specially designed swivel connector to record EMG signals and an IR based camcorder to record video.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.

View Article: PubMed Central - HTML - PubMed

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.

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.

Results and conclusion: 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.

Show MeSH
Related in: MedlinePlus