PT  - JOURNAL ARTICLE
AU  - Paul T. Salo
AU  - Jasmine A. Beye
AU  - Ruth A. Seerattan
AU  - Catherine A. Leonard
AU  - Tyler J. Ivie
AU  - Robert C. Bray
TI  - Plasticity of peptidergic innervation in healing rabbit medial collateral ligament
DP  - 2008 Jun 01
TA  - Canadian Journal of Surgery
PG  - 167--172
VI  - 51
IP  - 3
4099  - http://canjsurg.ca/content/51/3/167.short
4100  - http://canjsurg.ca/content/51/3/167.full
SO  - CAN J SURG2008 Jun 01; 51
AB  - Background: Denervation substantially impairs healing of the medial collateral ligament (MCL). Because normal ligaments are sparsely innervated, we hypothesized that neuropeptide-containing neurons would sprout or proliferate after ligament transection, followed by later regression with healing, in a manner analogous to blood vessels.Methods: We transected the right MCL in 9 mature female New Zealand white rabbits and killed 3 rabbits at 2, 6 or 14 weeks. Alternate sets of 12-mm serial sections of healing MCL scars were examined by fluorescent immunohistochemistry for substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and pan-neuronal marker PGP9.5.Results: Normal MCLs had few peptidergic fibres located in the epiligament in a perivascular pattern. At 2 weeks, PGP9.5-, SP- and CGRP-positive fibres had increased in the epiligament adjacent to the injury. By 6 weeks, there were increases in CGRP- and PGP9.5-positive fibres in epiligament and scar, with similar but less marked increases in SP-positive fibres. At 14 weeks, there was notable regression of immunostained peptidergic nerve fibres in the scar.Conclusion: This experiment shows evidence for a remarkable plasticity of ligament innervation after injury, supporting the idea that neuronal factors play a fundamental role in wound healing.