Abstract
Background. Transcutaneous electrical nerve stimulation (TENS) can be used as a physical therapy for spasticity, but the effects of TENS on spasticity and its underlying mechanisms remain unclear. Objective. The purpose of this study was to test the effects of TENS on spasticity and the role of activated microglia as underlying mechanisms of TENS treatment for spasticity in rats with a 50-mm contusive spinal cord injury (SCI). Methods. A spinal contusion was made at the T12 spinal segment in adult male Sprague-Dawley rats using the NYU impactor. Behavioral tests for motor function were conducted before and after SCI and before and after TENS application. To assess spasticity, the modified Ashworth scale (MAS) was used before and after SCI, high-frequency (HF)/low-frequency (LF) TENS application at 3 different intensities (motor threshold [MT], 50% and 90% MT) or minocycline administration. Immunohistochemistry for microglia was performed at the lumbar spinal segments. Results. Motor recovery reached a plateau approximately 28 days after SCI. Spasticity was well developed and was sustained above the MAS grade of 3, beginning at 28 days after SCI. HF-TENS at 90% MT significantly alleviated spasticity. Motor function did not show any significant changes with LF- or HF-TENS treatment. HF-TENS significantly reduced the proportion of activated microglia observed after SCI. Minocycline, the microglia inhibitor, also significantly alleviated spasticity with the reduction of activated microglia expression. Conclusions. These results suggest that HF-TENS at 90% MT alleviates spasticity in rats with SCI by inhibiting activated microglia.
| Original language | English |
|---|---|
| Pages (from-to) | 370-381 |
| Number of pages | 12 |
| Journal | Neurorehabilitation and Neural Repair |
| Volume | 29 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2015 May 27 |
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Keywords
- microglia
- spasticity
- spinal cord injury
- transcutaneous electrical nerve stimulation (TENS)
ASJC Scopus subject areas
- Clinical Neurology
- Rehabilitation
- Neurology
Cite this
High-frequency transcutaneous electrical nerve stimulation alleviates spasticity after spinal contusion by inhibiting activated microglia in rats. / Hahm, Suk Chan; Yoon, Young Wook; Kim, Junesun.
In: Neurorehabilitation and Neural Repair, Vol. 29, No. 4, 27.05.2015, p. 370-381.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High-frequency transcutaneous electrical nerve stimulation alleviates spasticity after spinal contusion by inhibiting activated microglia in rats
AU - Hahm, Suk Chan
AU - Yoon, Young Wook
AU - Kim, Junesun
PY - 2015/5/27
Y1 - 2015/5/27
N2 - Background. Transcutaneous electrical nerve stimulation (TENS) can be used as a physical therapy for spasticity, but the effects of TENS on spasticity and its underlying mechanisms remain unclear. Objective. The purpose of this study was to test the effects of TENS on spasticity and the role of activated microglia as underlying mechanisms of TENS treatment for spasticity in rats with a 50-mm contusive spinal cord injury (SCI). Methods. A spinal contusion was made at the T12 spinal segment in adult male Sprague-Dawley rats using the NYU impactor. Behavioral tests for motor function were conducted before and after SCI and before and after TENS application. To assess spasticity, the modified Ashworth scale (MAS) was used before and after SCI, high-frequency (HF)/low-frequency (LF) TENS application at 3 different intensities (motor threshold [MT], 50% and 90% MT) or minocycline administration. Immunohistochemistry for microglia was performed at the lumbar spinal segments. Results. Motor recovery reached a plateau approximately 28 days after SCI. Spasticity was well developed and was sustained above the MAS grade of 3, beginning at 28 days after SCI. HF-TENS at 90% MT significantly alleviated spasticity. Motor function did not show any significant changes with LF- or HF-TENS treatment. HF-TENS significantly reduced the proportion of activated microglia observed after SCI. Minocycline, the microglia inhibitor, also significantly alleviated spasticity with the reduction of activated microglia expression. Conclusions. These results suggest that HF-TENS at 90% MT alleviates spasticity in rats with SCI by inhibiting activated microglia.
AB - Background. Transcutaneous electrical nerve stimulation (TENS) can be used as a physical therapy for spasticity, but the effects of TENS on spasticity and its underlying mechanisms remain unclear. Objective. The purpose of this study was to test the effects of TENS on spasticity and the role of activated microglia as underlying mechanisms of TENS treatment for spasticity in rats with a 50-mm contusive spinal cord injury (SCI). Methods. A spinal contusion was made at the T12 spinal segment in adult male Sprague-Dawley rats using the NYU impactor. Behavioral tests for motor function were conducted before and after SCI and before and after TENS application. To assess spasticity, the modified Ashworth scale (MAS) was used before and after SCI, high-frequency (HF)/low-frequency (LF) TENS application at 3 different intensities (motor threshold [MT], 50% and 90% MT) or minocycline administration. Immunohistochemistry for microglia was performed at the lumbar spinal segments. Results. Motor recovery reached a plateau approximately 28 days after SCI. Spasticity was well developed and was sustained above the MAS grade of 3, beginning at 28 days after SCI. HF-TENS at 90% MT significantly alleviated spasticity. Motor function did not show any significant changes with LF- or HF-TENS treatment. HF-TENS significantly reduced the proportion of activated microglia observed after SCI. Minocycline, the microglia inhibitor, also significantly alleviated spasticity with the reduction of activated microglia expression. Conclusions. These results suggest that HF-TENS at 90% MT alleviates spasticity in rats with SCI by inhibiting activated microglia.
KW - microglia
KW - spasticity
KW - spinal cord injury
KW - transcutaneous electrical nerve stimulation (TENS)
UR - http://www.scopus.com/inward/record.url?scp=84925734754&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84925734754&partnerID=8YFLogxK
U2 - 10.1177/1545968314545172
DO - 10.1177/1545968314545172
M3 - Article
C2 - 25122586
AN - SCOPUS:84925734754
VL - 29
SP - 370
EP - 381
JO - Neurorehabilitation and Neural Repair
JF - Neurorehabilitation and Neural Repair
SN - 1545-9683
IS - 4
ER -