Aerobic capacity exercise effect on axon density and g-ratio during nerve regeneration

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doi:2013.22.2.163

Exerc Sci > Volume 22(2); 2013 > Article

Exercise Science 2013;22(2): 163-172. doi: https://doi.org/10.15857/ksep.2013.22.2.163

4주간의 유산소성 운동이 손상된 정중신경의 축삭돌기 밀집도(axon density) 및 G-ratio에 미치는 영향

박재성¹, 김동현², 김종식³

¹고려대학교
²성균관대학교
³원광대학교

Aerobic capacity exercise effect on axon density and g-ratio during nerve regeneration

ABSTRACT

Hand function and nerve regeneration was blinded for a long time without detailed study. Now we will start the study about the nerve regeneration and functional recovery of hand. To study the basics of hand function and nerve regeneration, we start the study of hand function recover and nerve regeneration mechanism. First target function was grip strength and median nerve. Exercise training improves motor function after clinical and experimental peripheral nervous lesion. However, it is not clear if clinical improvements are due to neuronal alterations within the affected axonal region or a result from a more general effect of exercise and motivation. In previous study, we found that treadmill exercise upregulate the neurotrophic factors in the mouse regeneration model. But still we don't know about the detailed signaling in the median nerve and interactions between them and exercise. The purpose of this study was to determine the effects of treadmill exercise on median nerve regeneration after cut and sutured, peripheral nerve regeneration mice model. The results of this study were summarized as follows. Treadmill exercise increases the number of regenerated axons in median nerve(axon density). and treadmill exercise group's G-ratio and myelin thickness are more proper than sedentary group in median nerve. This means exercise inhibits remyelination in the median nerve and induces the nerve regeneration. Also treadmill exercise increases GDNF expression levels in the median nerve rather than sedentary group. These results mean treadmill exercise profitable to prevent the wallerian degeneration and induce the neuronal regeneration in the injured median nerve. The results of this study suggest that treadmill exercise inhibits the nerve regeneration in the injured median nerve and these effects may offer a potential therapeutic adjunct to current nerve regeneration therapies in the future.

Key words: Nerve regeneration, Axon density, Myelination, G-ratio