Muscle Fiber Composition Changes after Selective Nerve Innervation

Abstract

Facial nerve paralysis interferes with mimetic muscle function. To reconstruct natural facial movement, free muscle flaps are transplanted as new muscles. However, it is difficult to maintain resting tonus. A dual innervation technique in which other nerves such as the hypoglossal nerve or contralateral facial nerve are added is often applied. Using 10-week-old rats (n = 10), the masseteric and hypoglossal nerves were cut, and the distal stump of the masseteric nerve and the proximal stump of the hypoglossal nerve were then sutured (suture group). In the other group, the masseteric nerve was cut and cauterized (cut group). Immunohistochemistry and microarray were performed on the extracted masseter muscle. The immunohistochemistry results suggested that the muscles in the suture group obtained oxidative characteristics. The microarray showed the genes involved in mitochondrial function, including Perm1. In summary, our data support the validity of the dualinnervation technique for facial paralysis treatment.

Highlights in Pathophysiology of the Musculoskeletal System

“…Still, based on in silico, in situ, and in vivo studies, the study by Radke et al [ 31 ] developed and reported a new method for the quantitative chemical exchange saturation transfer (qCEST) technique, a promising bio-sensitive MRI technique, in systems with multiple proton pools, to assess the biochemical composition of the intervertebral discs, allowing for the timely diagnosis of degenerative diseases. Moreover, the validity of the dual innervation technique for the facial paralysis treatment has been reported in a study by Watanabe et al [ 32 ]. The results of immunohistochemical and microarray analysis on the masseter muscle of rats subjected to masseteric and hypoglossal nerves suture, reported oxidative characteristics, supporting the validity of the technique.…”