title: The negative impact of traumatic brain injury (TBI) on bone in a mouse model.
abstract: BACKGROUND
  While it is well established that the brain produces hypothalamic hormones and neuropeptides that influence skeletal metabolism, the impact of traumatic brain injury (TBI) on bone is unknown. Based on the recognition from clinical studies that there is an association between TBI and long-term hypothalamic pituitary dysfunction, it was hypothesized that TBI exerts a negative impact on skeletal growth and maintenance.
  
  
  METHODS
  To test the hypothesis, this study employed a repetitive weight drop model for TBI. Four impacts were applied for four consecutive days on 5-week old female C57BL/6 J mice. Bone measurements were taken 2 weeks after the first impact.
  
  
  RESULTS
  Bone mineral content (BMC), bone area (B area) and bone mineral density (BMD) in the total body were reduced by 14.5%, 9.8% and 5.2%, respectively, in the impacted vs. control mice. There was a 17.1% reduction in total volumetric BMD (vBMD) and a 4.0% reduction in material vBMD in cortical bone. In trabecular bone, there was a 44.0% reduction in BV/TV. Although there was no change in the cross-sectional bone size, the tibial growth plate and the tibia itself were shortened.
  
  
  CONCLUSIONS
  The repetitive animal TBI model produced an immediate, strong negative impact on bone mass acquisition in young mice.
authors.affiliation: Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center , Loma Linda, CA , USA and.
authors.forename: Hongrun
authors.initials: H
authors.lastname: Yu
authors.forename: Heather
authors.initials: H
authors.lastname: Watt
authors.forename: Subburaman
authors.initials: S
authors.lastname: Mohan
mesh_terms: D000818:Animals; D015519:Bone Density; D001846:Bone Development; D001842:Bone and Bones / Q000378:metabolism*; D001930:Brain Injuries / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D015675:Osteocalcin / Q000378:metabolism*; D011979:Receptors, Pituitary Hormone / Q000378:metabolism*
chemical_list: D011979:Receptors, Pituitary Hormone; D015675:Osteocalcin