Effects of ageing on the total number of muscle fibers and motoneurons of the tibialis anterior and soleus muscles in the rat.
The age-related changes in the total number of muscle fibers and motoneurons of the tibialis anterior and soleus muscles were studied using 10-, 65-, and 135-week-old rats. The number of fast twitch muscle fibers was decreased at age 65 weeks, while the numbers of slow twitch fibers and of alpha motoneurons were decreased only later, at age 135 weeks. Therefore, the degenerative process of muscle fibers differs with the fiber type.
College of General Education, University of Tokushima, Japan.
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Ishihara
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Naitoh
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Katsuta
D000375:Aging; D000818:Animals; D005260:Female; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology*; D024510:Muscle Development; D009132:Muscles / Q000294:innervation; D009928:Organ Specificity; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values