Y. Nakao et al., EXTRACELLULAR FLUID PATHWAY INSIDE THE FACIAL-NERVE FASCICLES, The Annals of otology, rhinology & laryngology, 106(6), 1997, pp. 503-505
The extracellular fluid pathway in the facial nerve and the diffusion
of a tracer from the facial nerve to other cranial nerves was examined
in the rabbit. Sodium fluorescein solution was injected into either t
he facial nerve fascicles or the epineurial connective tissue as a tra
cer at the stylomastoid foramen and then localized by fluorescence mic
roscopy. In the facial nerve, fluorescence was observed in the endoneu
rium and external nerve sheath (epineurium and perineurium) through th
e geniculate ganglion following injection into the nerve fascicles. Th
e vestibular, trigeminal, and glossopharyngeal ganglia also showed flu
orescence on the injection side in ganglion cells and intercellular co
nnective tissues. The results suggested that the endoneurial connectiv
e tissue constitutes a diffusion pathway inside the facial nerve fasci
cles and that the extracellular fluid pathway from the facial nerve to
these cranial ganglia may be related to the neural spread of inflamma
tion or neoplastic metastasis.