Effect of locomotor training on muscle performance in the context of nerve–muscle communication dysfunction

Abstract

Introduction: The effects of locomotor training (LT) on skeletal muscle after peripheral nerve injury and acetylcholinesterase deficiency are not well documented. Methods: We determined the effects of LT on mouse soleus muscle performance after sciatic nerve transection with excision (full and permanent denervation), nerve transection (partial functional reinnervation), nerve crush (full denervation with full functional reinnervation), and acetylcholinesterase deficiency (alteration in neuromuscular junction functioning). Results: We found no significant effect of LT on the recovery of soleus muscle weight, maximal force in response to muscle stimulation, and fatigue resistance after nerve transection with or without excision. However, LT significantly increased soleus muscle fatigue resistance after nerve crush and acetylcholinesterase deficiency. Moreover, hindlimb immobilization significantly aggravated the deficit in soleus muscle maximal force production and atrophy after nerve crush. Conclusions: LT is beneficial, and reduced muscle use is detrimental for intrinsic muscle performance in the context of disturbed nerve-muscle communication.

AMPK controls exercise endurance, mitochondrial oxidative capacity, and skeletal muscle integrity

“…The isometric contractile properties of soleus muscles were studied in vitro , as described elsewhere (19). Muscles were soaked in an oxygenated Krebs solution (95% O 2 and 5% CO 2 ), containing 58.5 mM NaCl, 24 mM NaHCO 3 , 5.4 mM KCl, 1.2 mM KH 2 PO 4 , 1.8 mM CaCl 2 , 1 mM MgSO 4 , and 10 mM glucose (pH 7.4), and were maintained at a temperature of 22°C.…”

Balance and coordination training and endurance training after nerve injury

“…The muscle values found in the trained groups were better than in the NT group, indicating that the 2 training protocols prevented soleus muscle atrophy when the programs were initiated rapidly after sciatic nerve crush and continued for 4 weeks. Reduced muscle activity negatively affects intrinsic muscle performance . After a PNI, disuse has many effects on skeletal muscles and can promote muscle atrophy .…”

“…Furthermore, treadmill running, when initiated 1 week after nerve injury, promotes increased functional muscle afferent recovery . Locomotor training on a treadmill, when initiated 2 days after nerve crush injury and continued for 4 weeks, enhances fatigue resistance of reinnervated muscles; however, 2 weeks of training does not enhance fatigue resistance, and the training duration reduces neither muscle force deficits nor muscle atrophy …”

Évaluation de la capacité fonctionnelle chez des patients atteints de la dystrophie myotonique de type 1 /

“…Plusieurs auteurs ont démontré que cette amélioration de la capacité aérobie était comparable à celle de personnes saines (Ansved, 2001;Harper, 2001;Voet, van der Kooi et al, 2010;Hadj-Said et al, 2011). Ce type d'entraînement induit une augmentation de la densité mitochondriale, une amélioration de l'activité enzymatique oxydative et une augmentation des réserves de glycogène musculaire (Ansved, 2001).…”