Carraro Mattia, Harrison Robert V
a Auditory Science Laboratory, Program in Neuroscience and Mental Health, and Department of Otolaryngology - HNS , the Hospital for Sick Children , Canada ;
b Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto , Toronto , Canada ;
Acta Otolaryngol. 2016;136(4):385-90. doi: 10.3109/00016489.2015.1123291. Epub 2016 Jan 29.
Conclusion With age, in a mouse model, degenerative changes to the capillaries of the stria vascularis are observed. These range from a narrowing of vessel lumen to complete degeneration of strial vessels. Other vascular beds in the cochlea are relatively unchanged with age. Strial capillaries at the cochlear base are significantly more affected than those in mid-apical turns. Objectives Previous work suggests that age-related hearing loss is associated with degenerative changes to cochlear vasculature; the term strial presbyacusis is often cited. This study reports on vascular changes observed in a murine model of presbyacusis, analyzed using corrosion cast techniques. Methods A novel corrosion cast technique was developed to compare cochlear vasculature in control mice (non-presbycusic, CD1) and old (> 6 months) C57BL/6 animals. ABR measures indicated a significant age-related threshold elevation in the C57BL/6 mice. Cochlear vascular casts were imaged using scanning electron microscopy, and vessel degeneration was quantified by measuring capillary diameters. Results Corrosion casts of cochlear vasculature in 6-12 month old C57BL/6 mice reveal significant degeneration of stria vascularis. Other capillary beds (spiral ligament and the spiral limbus) appear unchanged. Comparison of strial capillary diameters reveals significantly more damage in basal/lower-turn regions compared with the cochlear mid-turn.
结论 在小鼠模型中，随着年龄增长，观察到血管纹毛细血管出现退行性变化。这些变化范围从血管腔狭窄到血管纹血管完全退化。耳蜗中的其他血管床随年龄增长相对无变化。耳蜗底部的血管纹毛细血管比中顶转处的受影响明显更严重。
目的 先前的研究表明，年龄相关性听力损失与耳蜗血管系统的退行性变化有关；常提及血管纹老年性聋这一术语。本研究报告了在老年性聋小鼠模型中观察到的血管变化，并使用铸型技术进行分析。
方法 开发了一种新型铸型技术，以比较对照小鼠（非老年性聋，CD1）和老年（>6个月）C57BL/6动物的耳蜗血管系统。听性脑干反应测量表明C57BL/6小鼠存在与年龄相关的显著阈值升高。使用扫描电子显微镜对耳蜗血管铸型进行成像，并通过测量毛细血管直径对血管退化进行量化。
结果 6至12个月大的C57BL/6小鼠耳蜗血管系统的铸型显示血管纹有明显退化。其他毛细血管床（螺旋韧带和螺旋缘）看起来未改变。血管纹毛细血管直径的比较显示，与耳蜗中转相比，基底/低转区域的损伤明显更严重。
