CAJ | 학술논문

目的：通过对Atoh1条件基因敲除小鼠及Mitf基因突变小鼠两个动物模型的研究，来验证毛细胞及血管纹两者的存活是否相互依赖，以及在内耳中是否存在钾离子从血管纹-毛细胞-支持细胞-血管纹循环通路。方法分别对一月龄两种模型小鼠进行ABR、CM、CAP和EP的测量。并用免疫组化和共聚焦显微镜以及耳蜗铺片、切片对两种模型小鼠的耳蜗Corti’s器和血管纹进行形态学观察。结果内淋巴的缺损可造成外毛细胞的凋亡，但内毛细胞依然能够存活。20 mV的内淋巴电位是外毛细胞存活所必须的。血管纹的生存及功能并不需要功能正常的Corti’s器的支持，同时内淋巴电位的产生及维持并不依赖毛细胞及支持细胞的钾离子循环的支持。结论成熟毛细胞的存活依赖于正常的血管纹功能和内淋巴的离子环境。然而，血管纹的存活及功能却并不依赖Corti’s器的功能。
목적：통과대Atoh1조건기인고제소서급Mitf기인돌변소서량개동물모형적연구，래험증모세포급혈관문량자적존활시부상호의뢰，이급재내이중시부존재갑리자종혈관문-모세포-지지세포-혈관문순배통로。방법분별대일월령량충모형소서진행ABR、CM、CAP화EP적측량。병용면역조화화공취초현미경이급이와포편、절편대량충모형소서적이와Corti’s기화혈관문진행형태학관찰。결과내림파적결손가조성외모세포적조망，단내모세포의연능구존활。20 mV적내림파전위시외모세포존활소필수적。혈관문적생존급공능병불수요공능정상적Corti’s기적지지，동시내림파전위적산생급유지병불의뢰모세포급지지세포적갑리자순배적지지。결론성숙모세포적존활의뢰우정상적혈관문공능화내림파적리자배경。연이，혈관문적존활급공능각병불의뢰Corti’s기적공능。
Objective To determine whether hair cells and stria vascularis depend on each other for functioning and survival. The atoh1 conditional knockout (Atoh1-CKO) mice and Mitf mutant mice were used for our study. The Atoh1-CKO mouse itself terminates the expression of Atoh1 in hair cells around birth. We used this model to determine whether absence of hair cells would affect development, functioning and survival of the stria vascularis. The other mouse model has a mutation of the microphthalmia-associated transcription factor (Mitf) gene expressed in melanocytes. Loss of melanocytes in the stria vascularis due to Mitf mutation causes abnormality of the stria morphology and functions, leading to hearing loss. We used this model to determine whether change of the electrochemical environment in the endolymph maintained by the stria vascu-laris would affect the functioning and survival of hair cells. Methods We used auditory brainstem response (ABR) to measure hearing thresholds and round window electrode to measure cochlear microphonics (CM) and compound action potential (CAP). Sharp electrode technique was used to measure endocochlear potential (EP). Hair cell and supporting cell morphology was ex-amined by immunocytochemistry and confocal microscopy. Thin sections of the cochlea were used to examine the morphology of strial vascularis and organ of Corti. Results showed that EP and stria morphology were unaffected when the organ of Corti had completely degenerated. However, stria defects led to progressive loss of outer hair cells (OHCs). Conclusion The surviv-al and normal operation of the stria vascularis do not depend on a functional organ of Corti. However, normal functioning of the stria vascularis is necessary for auditory functions and survival of adult OHCs.