Neuroactive substances in the human vestibular end organs.
In order to evaluate the involvement of neuroactive substances in the human vestibular periphery, the immunocytochemical distribution of substance P (SP), calcitonin gene-related peptide (CGRP), and choline acetyltransferase (ChAT) was examined. SP-like immunoreactivity (LI) was present around and beneath sensory hair cells, probably corresponding to their afferent nerve endings. SP-LI was found predominantly in subpopulations of the primary afferents distributed in the peripheral region of the end organs. ChAT-LI and CGRP-LI were found throughout as small puncta below the hair cell layer, probably corresponding to efferent endings. The present results indicate that these neuroactive substances, previously described in animals, are also distributed in the human vestibular periphery, and almost certainly contribute to human vestibular function.
Usami
S
S
Department of Otorhinolaryngology, Hirosaki University School of Medicine, Japan.
Matsubara
A
A
Shinkawa
H
H
Matsunaga
T
T
Kanzaki
J
J
D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002795:Choline O-Acetyltransferase / Q000032:analysis; D004525:Efferent Pathways / Q000473:pathology / Q000601:surgery; D018069:Hair Cells, Vestibular / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D009464:Neuroma, Acoustic / Q000473:pathology* / Q000601:surgery; D009479:Neuropeptides / Q000032:analysis*; D018377:Neurotransmitter Agents / Q000032:analysis*; D013373:Substance P / Q000032:analysis; D014725:Vestibular Nerve / Q000473:pathology* / Q000601:surgery
D009479:Neuropeptides; D018377:Neurotransmitter Agents; D013373:Substance P; D002795:Choline O-Acetyltransferase; D015740:Calcitonin Gene-Related Peptide