Affiliations: Department of Human Anatomy and Embryology, Faculty of
Medicine, University of Barcelona, c/ Casanova 143, 08036 Barcelona,
Spain | CAP Antón de Borja, Consorci Sanitari de
Terrassa, c/Edison-cantonada Marconi, s/n, 08191 Rubí, Barcelona,
Spain | Department of Neuroscience, Karolinska Institutet,
S-171 77 Stockholm, Sweden | Department of Rehabilitation Medicine, Karolinska
University Hospital Huddinge, S-141 86, Stockholm, Sweden
Abstract: Purpose: This study examines the proportions of regenerative and
collateral sprouting to the skin after peripheral nerve injury. Methods: In the first experimental paradigm, primary afferent
neurones were pre-labelled with Diamidino Yellow (DY), injected in digit 3,
followed by sciatic nerve section and repair. After three months of
regeneration, digit 3 was re-injected with Fast Blue (FB) to label regenerating
cells. Fluoro-Gold (FG) was applied to the femoral (FEM) and musculocutaneous
(MC) nerves four days later to quantify their contribution to the innervation.
In the second experimental paradigm, sciatic nerve was first sectioned and
repaired. Three months later, the sciatic was resected, and digit 3 injected
with FB. After four more days, FEM and MC were resected and FG injected in all
digits. Results: Neurones in dorsal root ganglion (DRG) L5 had a higher rate
of correct reinnervation of digit 3 (44–72%) than neurones in DRG L4
(14–44%). Like in control cases, only occasional axons were traced from
the FEM and MC. In the second experiment, only occasional labelled neurones
appeared. Conclusions: The results indicate differences in the capacity for
correct peripheral sensory reinnervation between segmental levels, and that in
this model collateral sprouting was practically non-existent compared to
regenerative sprouting.
Keywords: nerve regeneration, DRG, fluorescent dyes, adult rat
