Neuropeptide-like intraneuronal profiles in the human VIIIth cranial nerve.

Intraneuronal inclusion bodies corresponding to large dense core vesicles are described in the primary neurons of the cochleovestibular system. Their diameters ranged from 80 to 120 nm. Considering their morphologic characteristics and findings in previous immunohistochemical studies, the vesicles are likely to contain neuropeptides, particularly substance P or enkephalin.