Choline acetyltransferase immunoreactivity in the human vestibular end-organs

Authors

  • Akira Ishiyama,

    1. Temporal Bone and Molecular Biology Laboratories, Goodhill Ear Center, Division of Head and Neck Surgery, 31-24 Rehabilitation Center, UCLA School of Medicine, Los Angeles, California 90024-1794, USA
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  • Ivan Lopez,

    1. Temporal Bone and Molecular Biology Laboratories, Goodhill Ear Center, Division of Head and Neck Surgery, 31-24 Rehabilitation Center, UCLA School of Medicine, Los Angeles, California 90024-1794, USA
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  • Phillip A. Wackym

    Corresponding author
    1. Temporal Bone and Molecular Biology Laboratories, Goodhill Ear Center, Division of Head and Neck Surgery, 31-24 Rehabilitation Center, UCLA School of Medicine, Los Angeles, California 90024-1794, USA
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Corresponding author

ABSTRACT

Acetylcholine (ACh) is believed to play a major role in the efferent vestibular system in several animal models, however no information regarding the role of ACh in the human efferent vestibular system has been published. Post-embedding immunohistochemistry in a hydrophilic resin was used to investigate the choline acetyltransferase immunoreactivity (ChATi) and acetylcholinesterase (ACHE) histochemistry in human vestibular end-organs. ChATi and AChE activity was found in numerous bouton-type terminals at the basal area of the vestibular hair cells. These terminals were found to contact type II vestibular hair cells and the afferent chalices surrounding type I hair cells. This study provides the first evidence that the human efferent vestibular axons and terminals are cholinergic.

Ancillary