Abstract：
Thyroid hormone deficiency can lead to abnormal auditory development of varying severity. Retardation of morphological development, including delays in degeneration of Kölliker\'s organ and subsequent delayed formation of the inner sulcus, along with delayed opening of the tunnel of Corti and malformation of the tectorial membrane, was consistently observed in an antithyroid drug-induced congenital hypothyroidism rodent model. Abnormal morphological development could partly explain impaired adult auditory function. However, whether the development of inner hair cell ribbon synapses is influenced by hypothyroidism remains unclear. In the present study, we characterize the normal degeneration pattern of Kölliker\'s organ along the basal-to-apical axis. Then, we verified the retardation of morphological development in congenital hypothyroid mice. Using this model, we found that twisted collagen is present in the major tectorial membrane and delayed separation from supporting cells affects the minor tectorial membrane. Finally, we found that the number of synaptic ribbons was not significantly altered but the ribbon synapse maturation process was significantly impaired in congenital hypothyroid mice. We conclude that thyroid hormone is involved in structural development of the tectorial membrane and the ribbon synapse maturation process.
摘要：
甲状腺激素缺乏可导致不同严重程度的听觉发育异常。形态发育迟缓，包括Kölliker器官退化的延迟和随后的内沟延迟形成，随着Corti隧道的延迟开放和膜的变形，在抗甲状腺药物诱导的先天性甲状腺功能低下啮齿动物模型中始终观察到。形态发育异常可以部分解释成人听觉功能受损。然而,内毛细胞带状突触的发育是否受甲状腺功能减退的影响尚不清楚.在本研究中,我们描述了沿着基底到根尖轴的Kölliker器官的正常退化模式。然后，我们证实了先天性甲状腺功能减退小鼠的形态学发育迟缓。使用这个模型，我们发现，扭曲的胶原蛋白存在于主要的膜和延迟的分离支持细胞影响次要的膜。最后,我们发现，在先天性甲状腺功能减退小鼠中，突触带的数量没有明显改变，但带状突触的成熟过程明显受损。我们得出的结论是，甲状腺激素参与膜的结构发育和带状突触成熟过程。
