title: Immunohistochemical demonstration of sensory and autonomic nerve terminals in herniated lumbar disc tissue.
abstract: METHODS
  Thirty-five lumbar disc herniations removed at surgery were studied by indirect immunocytochemistry.
  
  
  OBJECTIVE
  To localize immunohistochemically both sensory and autonomic nerve terminals in disc herniations.
  
  
  BACKGROUND
  Using various more or less specific histologic and histochemical methods, investigators have reported the presence of free nerve terminals in disc tissue. However, very few studies have, to date, convincingly demonstrated nerve terminals in disc tissue that morphologically resemble the tiny nerve terminals of sensory and autonomic nerve fibers.
  
  
  METHODS
  Amplification of the peroxidase reaction product in avidin-biotin-peroxidase complex immunostaining by the glucose oxidase-diaminobenzidine-nickel sulfate method was used to visualize small punctate nerve terminals at high magnification. Thin frozen sections from disc herniation tissue prefixed in Zamboni fixative were incubated with antibodies to synaptophysin to visualize nerve terminals in general, and with antibodies to substance P and C-flanking peptide of neuropeptide Y to further characterize nerve terminals as either sensory or sympathetic.
  
  
  RESULTS
  Nerve terminals could be demonstrated in 29 (83%) of the 35 disc herniations. They were observed with the synaptophysin antibody in 17 of 35 (49%) disc herniations, with substance P in 16 of 35 (46%) disc herniations, and with C-flanking peptide of neuropeptide Y in 13 of 35 (37%) disc herniations. Morphologically, the nerve terminals were seen as tiny immunoreactive dots. Some of the nerve terminals were observed close to disc cells, possibly suggesting direct interaction.
  
  
  CONCLUSIONS
  Small nerve terminals in disc herniations, both sensory substance P endings and sympathetic C-flanking peptide of neuropeptide Y endings, could be involved in mechanisms of discogenic pain, disc tissue neurogenic inflammation, tissue repair processes after injury, and control of local blood circulation in the newly formed blood vessels. Disc cells may be directly affected by the neuropeptides released from nearby nerve terminals.
authors.affiliation: Spine Research Unit, University Central Hospital, Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Palmgren
authors.forename: M
authors.initials: M
authors.lastname: Grönblad
authors.forename: J
authors.initials: J
authors.lastname: Virri
authors.forename: S
authors.initials: S
authors.lastname: Seitsalo
authors.forename: M
authors.initials: M
authors.lastname: Ruuskanen
authors.forename: E
authors.initials: E
authors.lastname: Karaharju
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007405:Intervertebral Disc Displacement / Q000378:metabolism / Q000473:pathology*; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009411:Nerve Endings / Q000378:metabolism / Q000473:pathology*; D009478:Neuropeptide Y / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D012677:Sensation / Q000502:physiology*; D013194:Staining and Labeling; D013373:Substance P / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism
chemical_list: D009478:Neuropeptide Y; D010446:Peptide Fragments; D016708:Synaptophysin; D013373:Substance P