gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie
74. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie
96. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie
51. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

26. - 29.10.2010, Berlin

Recovery of whisking function after facial nerve injury in mice requires insulin-like growth factor 1 (IGF-1)

Meeting Abstract

  • E. Skouras - Uniklinik Köln, Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Köln, Germany
  • G. Schiffer - Uniklinik Köln, Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Köln, Germany
  • D.N. Angelov - Uniklinik Köln, Institut I für Anatomie, Köln, Germany
  • P. Eysel - Uniklinik Köln, Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Köln, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie. 74. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 96. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 51. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 26.-29.10.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocIN17-730

DOI: 10.3205/10dkou101, URN: urn:nbn:de:0183-10dkou1013

Published: October 21, 2010

© 2010 Skouras et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

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Objective: Recently, we showed that manual stimulation (MS) of denervated vibrissal muscles enhanced functional recovery following facial nerve cut and suture (FFA) by reducing poly-innervation at the neuro-muscular junctions (NMJ). Although the cellular correlates of poly-innervation are established, with terminal Schwann cells (TSC) processes attracting axon sprouts to “bridge” adjacent NMJ, molecular correlates are poorly understood.

Methods: Quantitative RT-PCR revealed a rapid increase of IGF-1 mRNA in denervated muscles and we examined the effect of daily MS for 2 months after FFA in IGF-1+/- heterozygous mice; controls were wild-type (WT) littermates. We quantified vibrissal motor performance and percentage of NMJ bridged by S100-positive TSC.

Results and conclusions: There were no differences between intact WT and IGF-1+/- mice for vibrissal whisking amplitude (48o and 49o) or the percentage of bridged NMJ (0%). After FFA and handling alone (i.e. no MS) in WT animals, vibrissal whisking amplitude was reduced (60% lower than intact) and the percentage of bridged NMJ increased (42% more than intact). MS improved both the amplitude of vibrissal whisking (not significantly different from intact) and the percentage of bridged NMJ (12% more than intact). After FFA and handling in IGF-1+/- mice, the pattern was similar (whisking amplitude 57% lower than intact; proportion of bridged NMJ 42% more than intact). However, MS did not improve outcome (whisking amplitude 47% lower than intact; proportion of bridged NMJ 40% more than intact).

We conclude that IGF-I is required to mediate the effects of MS on target muscle reinnervation and recovery of whisking function.