Distribution of Calcitonin Gene-Related Peptide Immunoreactive Nerve Fibers in Rat Cochlea and Brainstem Auditory Nuclei / 대한이비인후과학회지

ABSTRACT

BACKGROUND: Calcitonin gene-related peptide(CGRP) is one of the neuronal elements of the inner ear. CGRP immunoreactive fibers are known to regulate auditory action potential and blood flow of cochlea. OBJECTIVES: This study was designed to localize the CGRP immunoreactive fibers in the cochlear tissue and auditory brainstem of normal rat. MATERIAL AND METHODS: Male Sprague-Dawley rats were perfused with 4% paraformaldehyde. Cochleae and brainstems were taken out and processed for surface preparations and frozen sections. Immunoperoxidase immunohistochemistry was carried out using anti-CGRP polyclonal antibody. RESULTS: Numerous CGRP immunoreactive fibers were located in the inner spiral bundle, intraganglionic nerve fibers, base of inner hair cells and lateral superior olivary nuclei in brainstems. CONCLUSION: CGRP is one of the neuropeptides in the olivocochlear effent system and may participate in the inhibitory effect on auditory action potential.