title: Heterogeneous responses of dorsal root ganglion neurons in neuropathies induced by peripheral nerve trauma and the antiretroviral drug stavudine.
abstract: BACKGROUND
  Heterogeneity is increasingly recognized in clinical presentation of neuropathic pain (NP), but less often recognized in animal models. Neurochemical dysregulation in rodent dorsal root ganglia (DRG) is associated with peripheral nerve trauma, but poorly studied in non-traumatic NP conditions.
  
  
  METHODS
  This study aimed to investigate the temporal expressions of activating transcription factor-3 (ATF-3), growth-associated protein-43 (GAP-43), neuropeptide Y (NPY) and galanin in traumatic and non-traumatic rat models of neuropathies associated with NP. Expressions of these markers were examined in the DRG at different time points following tibial nerve transection (TNT) injury and antiretroviral drug stavudine (d4T) administration using immunohistochemistry. The development of sensory gain following these insults was assessed by measuring limb withdrawal to a punctate mechanical stimulus.
  
  
  RESULTS
  Both TNT-injured and d4T-treated rats developed hindpaw mechanical hypersensitivity. Robust expressions of ATF-3, GAP-43, NPY and galanin in both small- and large-sized L5 DRG neurons were observed in the DRG from TNT-injured rats. In contrast, d4T-treated rats did not exhibit any significant neurochemical changes in the DRG.
  
  
  CONCLUSIONS
  Taken together, the results suggest that ATF-3, GAP-43, NPY and galanin are likely indicators of nerve trauma-associated processes and not generic markers for NP. These experiments also demonstrate distinct expression patterns of neurochemical markers in the DRG and emphasize the mechanistic difference between nerve trauma and antiretroviral drug-associated NP.
authors: Pain Research Group, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK.
authors: E K
authors: EK
authors: Boateng
authors: A
authors: A
authors: Novejarque
authors: T
authors: T
authors: Pheby
authors: A S C
authors: AS
authors: Rice
authors: W
authors: W
authors: Huang
mesh_terms: D000818:Animals; D019380:Anti-HIV Agents / Q000494:pharmacology*; D019004:Galanin / Q000378:metabolism; D005727:Ganglia, Spinal / Q000187:drug effects*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism; D059348:Peripheral Nerve Injuries / Q000188:drug therapy*; D017208:Rats, Wistar; D018119:Stavudine / Q000494:pharmacology*
chemical_list: D019380:Anti-HIV Agents; D009478:Neuropeptide Y; D019004:Galanin; D018119:Stavudine