Response of spiral ganglion neurones to cochlear hair cell destruction in the guinea pig
Response of spiral ganglion neurones to cochlear hair cell destruction in the guinea pig
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DOI：
10.1023/a:1007201913730
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发表时间：
2000-07-01
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影响因子：
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通讯作者：
Mohuiddin, A
中科院分区：
文献类型：
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作者：
Dodson, HC;Mohuiddin, A
哺乳动物耳蜗毛细胞破坏后，神经节细胞的损失会持续很长一段时间，可能有不止一个因素促成了这一过程。尽管没有毛细胞，但一些神经节细胞能够存活相当长的时间。由于功能性神经节细胞对人工耳蜗的成功使用至关重要，因此需要更好地了解这些细胞对损伤的反应，以便预防或改善它们的损失。应用定量光学显微镜、电子显微镜和免疫细胞化学技术，观察豚鼠耳蜗内注射庆大霉素后1、3、6和30周时，Ⅰ型螺旋神经节神经元对毛细胞破坏的反应。确定神经节细胞损失的时间过程，同时对能够存活的那些细胞进行更仔细的检查。大量神经节细胞的显著早期损失随后是这些细胞在30周存活期的进一步显著损失。同时，还观察到中央纤维数量减少。存活的神经节细胞具有很少或没有核周髓鞘，其外观类似于妊娠55天的I型神经节细胞。还发现在最初损失中存活的神经节细胞具有比对照组显著更大的索马尺寸，尽管这没有保持，并且在30周存活时，少数剩余细胞的尺寸与对照组相似。生长相关蛋白GAP 43在存活3周的存活神经节细胞中上调，但在存活6周时出现减少。这些特征可能表明神经节细胞的生存反应，并可能提供一个基础上开发适当的手段，以防止其损失。
Loss of ganglion cells after hair cell destruction in the mammalian cochlea continues to occur over a long period of time, with the possibility of more than one factor contributing to this process. Despite the absence of hair cells, some ganglion cells are, however, able to survive for considerable periods of time. Because functional ganglion cells are crucial to the successful use of cochlear implants, a better understanding of the response of these cells to injury is required so that their loss can be prevented or ameliorated. Quantitative light microscopy, electron microscopy and immunocytochemical techniques were used to examine the response of type I spiral ganglion neurones to hair cell destruction, in guinea pigs at 1, 3, 6 and 30 weeks survival following intracochlear injection with gentamicin. The time course of ganglion cell loss was determined, while a closer examination of those cells able to survive was carried out. A significant early loss of large numbers of ganglion cells was followed by a further significant loss of these cells by 30-week survival. At the same time a decrease in the numbers of central fibres was also observed. Surviving ganglion cells have little or no perikaryal myelin, an appearance resembling that of type I ganglion cells at 55 days gestation. Ganglion cells surviving the initial loss were also found to have a significantly larger soma size than controls although this was not maintained and at 30 weeks survival the few remaining cells were similar in size to that of controls. The growth associated protein GAP 43 was upregulated in surviving ganglion cells at 3 weeks survival, but appeared diminished by 6 weeks survival. These features may indicate a survival response in ganglion cells and may provide a basis on which to develop appropriate means to prevent their loss.