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

我们研究了干细胞在实验动物听觉道中的植入，以寻找操纵听觉皮层关键期的可能性。我们将自体骨髓基质细胞（MSC）注射到氨基糖苷类损伤的耳蜗蜗轴中，并观察到大量的干细胞移植。 MSCs 的存活，其中一些分化为神经细胞，在颅骨骨髓细胞层上培养，与耳蜗感觉细胞共培养。在邻近毛细胞基底或基底外侧部分的 ES 细胞衍生神经元的神经突中观察到突触素的表达，这导致 ES 细胞的神经突大量伸长。我们还使用 SDIA 处理后的小鼠 ES 细胞作为移植物，使哈特利豚鼠耳聋。将 ES 细胞引入耳蜗蜗轴后，与未手术的动物相比，依他尼酸显示出明显较低的 eABR 阈值，这表明 SDIA 处理的 ES 细胞植入可能有助于恢复。这些结果表明使用干细胞植入来克服听觉神经系统的关键期的未来潜力。 18F-FDG 在正常听力志愿者中进行，并让他们观看说话者面部的无声视频，对他们的大脑进行正电子发射断层扫描 (PET) 扫描，结果显示视觉皮层、顶叶和颞上回后部 (STG) 显着激活。如果左半球的唇读激活在先天性耳聋受试者中占主导地位，那么语言的视觉方面的处理可能会在颞叶皮层中占主导地位，而颞叶皮层有望成为其中之一。口语习得关键期指标较少。