title: Dichotomizing sensory nerve fibers innervating both the lumbar vertebral body and the area surrounding the iliac crest: a possible mechanism of referred lateral back pain from lumbar vertebral body.
abstract: METHODS
  Animal study.
  
  
  OBJECTIVE
  To determine the existence of dichotomizing sensory nerve fibers innervating both the lumbar vertebral body and the area surrounding the iliac crest (ASIC).
  
  
  BACKGROUND
  Elderly patients with osteoporosis sometimes experience lumbar vertebral fracture and may feel diffuse nonlocalized pain in the back, the lateral portion of the trunk, and the ASIC. The pattern of sensory innervation of vertebral bodies remains unclear. DRG neurons with dichotomizing axons have been reported and are thought to be related to referred pain. The purpose of this study was to investigate the existence of dichotomizing axons to the lumbar vertebral bodies and the ASIC in rats.
  
  
  METHODS
  Two kinds of neurotracers (1,1´-dioctadecyl-3,3,3´,3´-tetramethylindocarbocyanine perchlorate [DiI] and Fluoro-Gold [FG]) were used. DiI crystals were placed in the left ASIC, and FG was applied into the L2 vertebral body in 10 rats. Four weeks later, left DRGs from L1 to L6 were resected, sectioned, and observed under a fluorescence microscope.
  
  
  RESULTS
  DiI-labeled DRG neurons innervating the ASIC and FG-labeled DRG neurons innervating the vertebral L2 body were distributed from L1 to L6. The ratio of total double-labeled per total DiI-labeled DRG neurons was 10.2%, and that of total double-labeled per total FG-labeled DRG neurons was 14.7%. These double-labeled DRG neurons innervating the L2 vertebral body had other axons that extended to the ASIC.
  
  
  CONCLUSIONS
  This finding provides a possible neuroanatomical explanation for referred pain in the ASIC from vertebral bodies.
authors: From the Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Tatsuya
authors: T
authors: Fujii
authors: Yoshihiro
authors: Y
authors: Sakuma
authors: Sumihisa
authors: S
authors: Orita
authors: Gen
authors: G
authors: Inoue
authors: Nobuyasu
authors: N
authors: Ochiai
authors: Kazuki
authors: K
authors: Kuniyoshi
authors: Yasuchika
authors: Y
authors: Aoki
authors: Tetsuhiro
authors: T
authors: Ishikawa
authors: Masayuki
authors: M
authors: Miyagi
authors: Hiroto
authors: H
authors: Kamoda
authors: Miyako
authors: M
authors: Suzuki
authors: Gou
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authors: Kubota
authors: Kazuhide
authors: K
authors: Inage
authors: Takeshi
authors: T
authors: Sainoh
authors: Jun
authors: J
authors: Sato
authors: Kazuyo
authors: K
authors: Yamauchi
authors: Tomoaki
authors: T
authors: Toyone
authors: Junichi
authors: J
authors: Nakamura
authors: Shunji
authors: S
authors: Kishida
authors: Kazuhisa
authors: K
authors: Takahashi
authors: Takana
authors: T
authors: Koshi
authors: Seiji
authors: S
authors: Ohtori
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D017116:Low Back Pain / Q000209:etiology / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000294:innervation*; D018482:Muscle, Skeletal / Q000294:innervation; D009412:Nerve Fibers / Q000473:pathology*; D009475:Neurons, Afferent / Q000473:pathology; D053591:Referred Pain / Q000209:etiology / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016103:Spinal Fractures / Q000150:complications / Q000503:physiopathology*