Electrical stimulation of paralyzed vibrissal muscles reduces endplate reinnervation and does not promote motor recovery after facial nerve repair in rats.
The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.
Sinis
Nektarios
N
Department of Hand-, Plastic-, and Reconstructive Surgery with Burn Unit, BG-Trauma Centre, University of Tuebingen, Germany.
Horn
Frauke
F
Genchev
Borislav
B
Skouras
Emmanouil
E
Merkel
Daniel
D
Angelova
Srebrina K
SK
Kaidoglou
Katerina
K
Michael
Joern
J
Pavlov
Stoyan
S
Igelmund
Peter
P
Schaller
Hans-Eberhard
HE
Irintchev
Andrey
A
Dunlop
Sarah A
SA
Angelov
Doychin N
DN
D000818:Animals; D001369:Axons / Q000502:physiology; D004558:Electric Stimulation; D004566:Electrodes; D005154:Facial Nerve / Q000502:physiology* / Q000503:physiopathology; D020220:Facial Nerve Injuries / Q000628:therapy; D005260:Female; D009045:Motor Endplate / Q000502:physiology*; D009121:Muscle Denervation / Q000379:methods*; D009416:Nerve Regeneration / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D014738:Vibrissae / Q000294:innervation* / Q000502:physiology; D014741:Video Recording