title: Comparison of Peripheral Nerve Axonal Area Differences in Central and Peripheral Zones of Injured and Repaired Nerves.
abstract: BACKGROUND
  Histological analysis remains a cornerstone approach for the investigation of peripheral nerve regeneration. This study investigates a newly recognized histological difference between peripheral and central zones within the regenerating nerve trunks.
  
  
  OBJECTIVE
  The purpose of the study was to determine if the nerve axonal area (NXA) in regenerating peripheral nerves differs within central and peripheral areas, when viewed in cross-section.
  
  
  METHODS
  A total of 14 rats were divided into two groups, and subjected to different injuries to the right sciatic nerve. Group 1: Transection injury with immediate repair. Group 2: Crush injury without any treatment. The left sciatic nerve was left uninjured and served as a control in each rat. Following 4 weeks of recovery, nerve trunk cross-sections were prepared. Computerized techniques were then employed to divide nerve sections into central and peripheral zones and calculate corresponding NXA values for subsequent statistical analysis.
  
  
  RESULTS
  NXA of injured nerves was greater within peripheral as compared with the central zones, independent of injury type (p < 0.05). No statistically significant difference existed within the control groups or between the injury methods with regards to NXA regeneration extent.
  
  
  CONCLUSIONS
  NXA in regenerating peripheral nerves was greater in the peripheral zones than within the central zones.
authors.affiliation: Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Thayer
authors.affiliation: Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Ji-Geng
authors.initials: JG
authors.lastname: Yan
authors.affiliation: Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Lin-Ling
authors.initials: LL
authors.lastname: Zhang
authors.affiliation: Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Robert
authors.initials: R
authors.lastname: Havlik
authors.affiliation: Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Michael
authors.initials: M
authors.lastname: Agresti
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology*; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D008297:Male; D009416:Nerve Regeneration / Q000502:physiology*; D019635:Neurosurgical Procedures / Q000379:methods; D059348:Peripheral Nerve Injuries / Q000473:pathology* / Q000601:surgery*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D019651:Plastic Surgery Procedures / Q000379:methods; D018570:Risk Assessment; D012584:Sciatic Nerve / Q000293:injuries / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome