耳蜗血管交感及感觉神经双重调节的形态学证据

Morphological Evidences of Sympathetic Nerve and Sensory Nerve Regulating Cochlear Vessels

目的 研究酪氨酸羟化酶 (tyrosinehydroxylase,TH)和钙基因相关肽 (calcitoningene -relatedpeptide ,CGRP)在蜗轴螺旋动脉 (spiralmodiolarartery ,SMA)的定位及共存。方法 解剖显微镜下分离豚鼠SMA及其分支。采用TH及CGRP抗体及免疫组织化学ABC法和双标免疫荧光共聚焦定位技术。结果 TH、CGRP阳性的神经纤维分布于SMA的全长及其分支 ,两者均呈神经纤维网包绕SMA。标记的神经纤维有明显的分支和交叉 ,含明显的膨体 ,直径差异较大。纤维的密度随动脉走行逐渐降低。荧光双标共聚焦显微镜观察显示 ,在豚鼠的SMA ,TH、CGRP免疫反应阳性的神经纤维部分共存。结论 CGRP和肾上腺素能神经纤维共同参予对耳蜗血流的调节。

Objective To investigate localization and co-existence of the tyrosine hydroxylase (TH)and calcitonin gene-related peptide(CGRP)on the cochlear spiral modiolar artery(SMA) and its branches.Methods The SMA was dissected from the modiolus so that the entire length of the vessel and many of its branches could be observed. Immunohistochemical ABC method and confocal immunoflurescence technique were employed to localize each compound and to determine whether the TH and CGRP coexist in neurons of the SMA.Results Microscopic examination of whole vessel preparation revealed numerous TH and CGRP-positive neural networks innervating the SMA and its branches.The labeled nerve fibers showed distinct arborization ,varicosities and overlap,and were of different diameters. The overall distribution of neuronal labeling suggested a gradual decrease of innervation density from proximal (cochlear base)to more distal vessels, i.e., apical cochlear vessels and lateral radiating arterioles. Confocal immunofluorescence microscopy of double-labeled TH and CGRP neurons showed that a number of the TH-and CGRP-positive neurons were co-labeled. Thus, TH and CGRP partially co-exist within the neuronal innervation of SMA.Conclusion These findings support a hypothesis that specific neuropeptide and adrenergic neurons regulate cochlear blood flow.