title: Early postnatal motor experience shapes the motor properties of C57BL/6J adult mice.
abstract: This study aimed to evaluate the long-term consequences of early motor training on the muscle phenotype and motor output of middle-aged C57BL/6J mice. Neonatal mice were subjected to a variety of motor training procedures, for 3 weeks during the period of acquisition of locomotion. These procedures are widely used for motor training in adults; they include enriched environment, forced treadmill, chronic centrifugation, and hindlimb suspension. At 9 months, the mice reared in the enriched environment showed a slower type of fibre in slow muscles and a faster type in fast muscles, improved performance in motor tests, and a modified gait and body posture while walking. The proportion of fibres in the postural muscles of centrifuged mice did not change, but these mice showed improved resistance to fatigue. The suspended mice showed increased persistence of immature hybrid fibres in the tibialis, with a slower shift in the load-bearing soleus, without any behavioural changes. The forced treadmill was very stressful for the mice, but had limited effects on motor output, although a slower profile was observed in the tibialis. These results support the hypothesis that motor experience during a critical period of motor development shapes muscle phenotype and motor output. The different impacts of the various training procedures suggest that motor performance in adults can be optimized by appropriate training during a defined period of motor development.
authors.affiliation: Department of Physiology, Pharmacology & Neuroscience, Sophie Davis School of Biomedical Education, City College of New York/CCNY, New York, NY, USA.
authors.forename: Nadjet
authors.initials: N
authors.lastname: Serradj
authors.forename: Florence
authors.initials: F
authors.lastname: Picquet
authors.forename: Marc
authors.initials: M
authors.lastname: Jamon
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005684:Gait; D006614:Hindlimb / Q000254:growth & development / Q000294:innervation / Q000502:physiology*; D019417:Hindlimb Suspension; D008124:Locomotion; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000254:growth & development / Q000294:innervation / Q000502:physiology*; D005082:Physical Exertion; D011187:Posture
keywords: development; endurance training; hindlimb suspension; hypergravity; locomotion