Motor Fibre Organization in the Intratemporal Portion of Cat and Rat Facial Nerve studied with the horseradish Peroxidase Technique

Publisher Website
Google Scholar
Abstract
The intra-axonal transport of horseradish peroxidase (HRP) was used to label fibers in the intratemporal facial nerve portion (ITFN) in the rat and cat. HRP was applied to the proximal cut end of facial nerve branches innervating different facial muscles. Following appropriate survival periods, the animals were fixed by perfusion. The ITFN was processed histochemically for demonstration of intra-axonal HRP, using tetramethylbenzidine as substrate. The distribution of labelled fibers was analyzed in serial longitudinal sections and in photographic transverse-like reconstructions from 3 selected levels. HRP-labeled fibers from all examined motor branches were diffusely distributed almost throughout the entire ITFN, leaving only a narrow zone free of label. HRP applied to the chorda tympani nerve showed that this zone harbors fibers of this nerve. The motor fibers to the facial muscles are diffusely organized in the ITFN.