Glass Tiffany J, Valmadrid Luke Carmichael V, Connor Nadine P
Department of Surgery, University of Wisconsin-Madison, Madison, WI, United States.
Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, WI, United States.
Front Neurosci. 2019 Aug 29;13:906. doi: 10.3389/fnins.2019.00906. eCollection 2019.
There are increased risks for deglutition disorders in people with Down syndrome (DS). Although mouse models have been used to study the biological underpinnings of DS in other areas, relatively little is known about swallowing phenotypes in these models. We hypothesized that swallowing performance would be affected in adult mouse models of DS, relative to typical control mice. Videofluoroscopic swallow studies (VFSS) were conducted on adults of two mouse models of DS: Ts65Dn and Dp(16)1Yey, and evaluated in comparison with age-matched controls. Relative to other groups, adult Ts65Dn showed significantly slower swallow rates, longer inter-swallow intervals (ISI), and greater numbers of jaw excursion cycles preceding each swallow. In contrast, adult Dp(16)1Yey mice showed swallowing performance similar to control mice. Exploratory quantitative analyses of the intrinsic tongue (transverse muscle), and extrinsic tongue muscles [genioglossus (GG), styloglossus (SG), and hyoglossus (HG)] showed no significant differences between genotype groups in myosin heavy chain isoform profiles. Collectively, these findings suggest that while swallowing is typical in adult Dp(16)1Yey, swallowing in adult Ts65Dn is atypical due to unknown causes. The finding that adult Ts65Dn may have utility as a model of dysphagia provides new opportunities to elucidate biological underpinnings of dysphagia associated with DS.
唐氏综合征（DS）患者发生吞咽障碍的风险增加。尽管小鼠模型已被用于研究DS在其他领域的生物学基础，但对于这些模型中的吞咽表型知之甚少。我们假设，相对于典型的对照小鼠，DS成年小鼠模型的吞咽功能会受到影响。对两种DS小鼠模型（Ts65Dn和Dp(16)1Yey）的成年小鼠进行了视频荧光吞咽研究（VFSS），并与年龄匹配的对照小鼠进行比较评估。相对于其他组，成年Ts65Dn小鼠的吞咽速度明显较慢，吞咽间隔时间（ISI）更长，每次吞咽前的下颌运动周期更多。相比之下，成年Dp(16)1Yey小鼠的吞咽功能与对照小鼠相似。对舌内肌（横肌）和舌外肌[颏舌肌（GG）、茎突舌肌（SG）和舌骨舌肌（HG）]的探索性定量分析表明，基因型组之间在肌球蛋白重链异构体谱方面没有显著差异。总体而言，这些发现表明，虽然成年Dp(16)1Yey小鼠的吞咽功能正常，但成年Ts65Dn小鼠的吞咽功能异常，原因不明。成年Ts65Dn小鼠可作为吞咽困难模型这一发现为阐明与DS相关的吞咽困难的生物学基础提供了新机会。
