Kong Wie-Jia, Scholtz Arne W, Kammen-Jolly Keren, Glückert Rudolf, Hussl Burkhard, von Cauvenberg Paul B, Schrott-Fischer Anneliese
Department of Otolaryngology, University of Innsbruck, Anichstrasse 35, 6020-Innsbruck, Austria.
Eur J Neurosci. 2002 Feb;15(3):487-97. doi: 10.1046/j.0953-816x.2001.01880.x.
Calcitonin gene-related peptide (CGRP) is a neuropeptide widely distributed in the peripheral and central nervous system. Demonstrated in the efferent systems of the mammalian cochlea and vestibule, immunoreactive patterns of CGRP may vary by species. There is, however, no information in the literature investigating CGRP localization in the human cochlea. In the present study, the ultrastructural localization of CGRP immunoreactivity was evaluated in the human inner ear with immunoelectron microscopy. It was found that, in human cochlea, CGRP immunoreactivity was located in unmyelinated nerve fibres of the spiral lamina, inner spiral fibres beneath inner hair cells, tunnel spiral fibres, tunnel crossing fibres and outer radial fibres. In endorgans of human vestibule, CGRP immunoreactivity was located in vesiculated nerve fibres and bouton-type nerve terminals which were seen to contact afferent nerve chalices surrounding type I sensory cells and afferent nerve fibres, or to form an en passant contact with afferent dendrites. CGRP immunoreactivity appeared to be confined to efferent systems in all cases. This study presents evidence that CGRP could serve a role in neurotransmission or neuroregulation in both cochlear and vestibular efferent systems of human.
降钙素基因相关肽（CGRP）是一种广泛分布于外周和中枢神经系统的神经肽。在哺乳动物耳蜗和前庭的传出系统中已得到证实，CGRP的免疫反应模式可能因物种而异。然而，文献中尚无关于CGRP在人耳蜗中定位的研究信息。在本研究中，采用免疫电子显微镜技术评估了人内耳中CGRP免疫反应性的超微结构定位。结果发现，在人耳蜗中，CGRP免疫反应性位于螺旋板的无髓神经纤维、内毛细胞下方的内螺旋纤维、隧道螺旋纤维、隧道交叉纤维和外放射状纤维中。在人前庭的终器中，CGRP免疫反应性位于泡状神经纤维和纽扣型神经末梢，这些神经纤维和末梢可见与围绕I型感觉细胞的传入神经杯和传入神经纤维接触，或与传入树突形成旁触。在所有情况下，CGRP免疫反应性似乎都局限于传出系统。本研究提供了证据表明，CGRP可能在人耳蜗和前庭传出系统的神经传递或神经调节中发挥作用。
