Department of Psychology, University of Maryland, College Park, MD 20742, USA.
Hear Res. 2010 Oct 1;269(1-2):56-69. doi: 10.1016/j.heares.2010.07.003. Epub 2010 Jul 16.
Belgian Waterslager (BW) canaries have an inherited hearing loss due to missing and abnormal hair cells, but it is unclear whether the loss is congenital or developmental. We used auditory brainstem responses and scanning electron microscopy to describe the development of auditory sensitivity and hair cell abnormalities in BW and non-BW canaries. In both strains, adult ABR thresholds were higher than behavioral thresholds, but BW canaries exhibited higher thresholds than non-BW canaries across all frequencies. Immediately post-hatch, ABR thresholds and hair cell numbers were similar in both strains. Two weeks later, thresholds were significantly higher in BW canaries, and hair cell number progressively decreased as the birds aged. These data show that in BW canaries: the peripheral auditory system is functionally similar to non-BW canary from hatch to 2 weeks, ABR thresholds improve during this developmental period, actually becoming better than those of adults, but then worsen as the bird continues to age. Hair cell number and appearance is similar to non-BW canaries at hatch but progressively declines after 30 days of age. These data show that the hearing loss characteristic of BW canaries is, at least in part, developmental and is established by the time song learning begins.
比利时水域（BW）金丝雀由于毛细胞缺失和异常而患有遗传性听力损失，但尚不清楚这种损失是先天性的还是后天性的。我们使用听觉脑干反应和扫描电子显微镜来描述 BW 和非 BW 金丝雀听觉敏感性和毛细胞异常的发育。在这两种品系中，成年 ABR 阈值均高于行为阈值，但 BW 金丝雀在所有频率下的阈值均高于非 BW 金丝雀。孵出后立即，两种品系的 ABR 阈值和毛细胞数量相似。两周后，BW 金丝雀的阈值显着升高，并且随着鸟类年龄的增长，毛细胞数量逐渐减少。这些数据表明，在 BW 金丝雀中：从孵化到 2 周龄，外周听觉系统在功能上与非 BW 金丝雀相似，在此发育期间，ABR 阈值提高，实际上比成年鸟更好，但随着鸟类继续衰老而恶化。毛细胞数量和外观在孵化时与非 BW 金丝雀相似，但在 30 天后逐渐下降。这些数据表明，BW 金丝雀的听力损失特征至少部分是后天的，并在开始学习唱歌时就已经确定。
