title: Changes over time in structural plasticity of trabecular bone in rat tibiae immobilized by reversible sciatic denervation.
abstract: OBJECTIVE
  The present study aimed to clarify the structural recovery, and to compare the time course of morphological changes in trabeculae and the process of bone mass change in rat tibiae following temporary immobilization of hind limb by sciatic neurectomy or nerve freezing.
  
  
  METHODS
  In 11-week-old male Fischer 344 rats, 4-5 mm of the sciatic nerve was removed (neurectomy group) or frozen by 5-second application of a stainless steel rod immersed in liquid nitrogen (nerve-freezing group). Quantitative changes in cancellous bone were assessed by histomorphometry.
  
  
  RESULTS
  The results clarified that: trabecular bone volume (BV/TV) decreases until 3 weeks after denervation, and in the nerve-freezing group, it then increases from week 4, recovering to pre-surgery levels by week 10 (no recovery was seen in the neurectomy group); in the initial phase of bone atrophy, the decrease in BV/TV is more gradual in the nerve-freezing group than in the neurectomy group; and changes in trabecular architecture in the bone atrophy-recovery process are strongly associated with changes in trabecular thickness.
  
  
  CONCLUSIONS
  The findings suggested that after transient injury by nerve freezing and subsequent recovery of neuromuscular function, bone tissue undergoes recovery from bone loss, but that trabeculae may not show complete structural recovery.
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami, Kitaku, Niigata, Japan. hiroyuki-tamaki@nuhw.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Tamaki
authors.forename: K
authors.initials: K
authors.lastname: Yotani
authors.forename: F
authors.initials: F
authors.lastname: Ogita
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Kirimto
authors.forename: H
authors.initials: H
authors.lastname: Onishi
authors.forename: N
authors.initials: N
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D016723:Bone Remodeling / Q000502:physiology*; D003714:Denervation; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D012584:Sciatic Nerve / Q000601:surgery; D013977:Tibia / Q000294:innervation / Q000473:pathology*; D013995:Time