title: Altered bone development in a mouse model of peripheral sensory nerve inactivation.
abstract: OBJECTIVE
  The present study sought to determine the effects of decreased peripheral sensory nerve function on skeletal development and bone metabolism in mice.
  
  
  METHODS
  C57BL/6 neonatal mice were treated with capsaicin to induce peripheral sensory nerve degeneration, and compared to vehicle-treated controls at 4, 8 and 12 weeks of age. Changes in bone structure were assessed using micro-computed tomography, mechanical properties and fracture resistance were assessed using three-point bending of radii, and bone turnover was assessed using dynamic histomorphometry and serum biomarkers.
  
  
  RESULTS
  Capsaicin treatment resulted in small but significant decreases in bone structure, particularly affecting trabecular bone. Capsaicin-treated mice exhibited lower trabecular thickness at the femoral metaphysis and L5 vertebral body compared with vehicle-treated mice. However, capsaicin- and vehicle-treated mice had similar mechanical properties and bone turnover rates.
  
  
  CONCLUSIONS
  Neonatal capsaicin treatment affected trabecular bone during development; however these small changes may not be meaningful with respect to bone strength under normal loading conditions. It is possible that capsaicin-sensitive neurons may be more important for bone under stress conditions such as increased mechanical loading or injury. Future studies will investigate this potential role of peripheral sensory nerves in bone adaptation.
authors.affiliation: University of California-Davis Medical Center, Department of Orthopaedic Surgery.
authors.forename: M A
authors.initials: MA
authors.lastname: Heffner
authors.forename: M J
authors.initials: MJ
authors.lastname: Anderson
authors.forename: G C
authors.initials: GC
authors.lastname: Yeh
authors.forename: D C
authors.initials: DC
authors.lastname: Genetos
authors.forename: B A
authors.initials: BA
authors.lastname: Christiansen
mesh_terms: D000818:Animals; D001846:Bone Development / Q000187:drug effects / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000294:innervation* / Q000378:metabolism*; D002211:Capsaicin / Q000633:toxicity; D051379:Mice; D008810:Mice, Inbred C57BL; D009410:Nerve Degeneration / Q000139:chemically induced; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced; D018689:Sensory System Agents / Q000633:toxicity; D014057:Tomography, X-Ray Computed
chemical_list: D018689:Sensory System Agents; D002211:Capsaicin