Neural mechanism for critical period of the auditory cortex

听觉皮层关键期的神经机制

基本信息

批准号：
14370542
负责人：
HIRAUMI Harukazu
金额：
$ 8.32万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

We studied on stem cell implantation in the auditory tract of experimental animals in search for possibilities of manipulating the critical period of the auditory cortex. We injected autologous bone marrow stromal cells (MSC) into the modiolus of the cochlea damaged by aminoglycoside, and observed massive survival of MSCs, some of which differentiated into neuronal cells. Mouse embryonic stem cells (ES cells) cultured on skull bone marrow cell layer were co-cultured with cochlear sensory epithelium, which resulted in massive elongation of neurites from ES cells and attachment of the neurites to hair cells. Expression of synaptophysin was observed in the neurites of ES cell-derived neurons adjacent to the basal or basolateral portion of hair cells. These findings indicate a high potential of ES cells to differentiate into auditory tract neurons. We also used mouse ES cells after treatment with the SDIA as transplants. Hartley guinea pigs deafened by kanamycin and ethacrynic acid were us … More ed as recipient animals. ES cells were introduced into the cochlear modiolus. Transplanted cochleae exhibited significantly lower eABR thresholds in comparison with those of non-operated ones, which suggests possible contribution of SDIA-treated ES cell implantation to retrieval of auditory function. These results suggest future potential of using stem cell implantation to overcome critical period of the auditory nervous system. As for studies by functional brain imaging, we used 18F-FDG in normal hearing volunteers and let them watch silent video of a speaker's face. Positron emission tomography (PET) scan of their brain revealed significant activation of visual cortex, parietal lobe and the posterior portion of the superior temporal gyrus(STG) in the left hemisphere. If this lip reading activation of the left STG become dominant in congenitally deafened subjects, processing of visual aspects of language may be prevailing in the temporal cortex, which is expected to become one of the indicators for critical period of spoken language acquisition. Less

我们研究了实验动物的听觉界的干细胞植入，以寻找操纵可能的关键时期。我们将自体骨髓基质细胞（MSC）注射到通过氨基糖苷的耳蜗损伤的模量中，并观察到MSC的大量存活，其中一些分化为神经元细胞。将在颅骨骨髓细胞层培养的小鼠胚胎干细胞（ES细胞）与耳蜗感觉上皮共培养，这导致神经细胞的神经细胞大量伸长，并将神经网络的附着在毛细胞上。在与毛细胞基底或基底外侧部分相邻的ES细胞衍生神经元的神经元中观察到突触素的表达。这些发现表明，ES细胞分化为听觉道神经元的高潜力。用SDIA处理后，我们还使用了小鼠ES细胞作为移植。卡纳米霉素和乙酸乙酸摧毁的哈特利几内亚猪是我们……更像是接受动物。将ES细胞引入人工耳蜗中。与非手术的耳蜗相比，移植的耳蜗暴露于EABR阈值明显较低，这表明SDIA处理的ES植入对检索听觉功能的可能贡献。这些结果表明，使用干细胞植入来克服听觉神经系统系统的关键时期的未来潜力。至于功能性脑成像的研究，我们在正常的听力志愿者中使用了18F-FDG，并让他们观看说话者脸的无声视频。其大脑的正电子发射断层扫描（PET）扫描显示，左半球的临时回（STG）的视觉皮层，顶叶和后部的后部显着激活。如果左STG的这种唇读激活在先天性破坏的受试者中占主导地位，那么在临时皮质中可能会占上风语言的视觉方面，这将成为口语习得的关键时期的指标之一。较少的