David Geffen School of Medicine, University of California, Los Angeles, California, USA.
Department of Pathology, University of California, Los Angeles, California, USA.
Laryngoscope. 2024 Jan;134(1):264-271. doi: 10.1002/lary.30928. Epub 2023 Jul 31.
Despite gross anatomic and histologic differences between human and canine vocal folds, similar wave patterns have been described yet not fully characterized. We reconstructed vocal fold (VF) vibration in a canine hemilarynx and performed histologic examination of the same vocal fold. We demonstrate comparable wave patterns while exploring the importance of certain anatomic architectures.
An in vivo canine hemilarynx was phonated against a glass prism at low and high muscle activation conditions. Vibration was captured using high-speed video, and trajectories of VF medial surface tattooed landmarks were 3D-reconstructed. The method of empirical eigenfunctions was used to capture the essential dynamics of vibratory movement. Histologic examination of the hemilarynx was performed.
Oscillation patterns were highly similar between the in vivo canine and previous reports of ex vivo human models. The two most dominant eigenfunctions comprised over 90% of total variance of movement, representing opening/closing and convergent/divergent movement patterns, respectively. We demonstrate a vertical phase difference during the glottal cycle. The time delay between the inferior and superior VF was greater during opening than closing for both activation conditions. Histological examination of canine VF showed not only a thicker lamina propria layer superiorly but also a distinct pattern of thyroarytenoid muscle fibers and fascicles as described in human studies.
Histologic and vibratory examination of the canine vocal fold demonstrated human vocal fold vibratory patterns despite certain microstructural differences. This study suggests that the multilayered lamina propria may not be fundamental to vibratory patterns necessary for human-like voice production.
NA (Basic science study) Laryngoscope, 134:264-271, 2024.
尽管人和犬的声带在大体解剖和组织学上存在差异，但已有研究描述了相似的波型，只是尚未对其进行充分的特征描述。本研究在犬半喉中重建声带（VF）振动，并对同一声带进行组织学检查。我们在探索某些解剖结构的重要性的同时，展示了具有可比性的波型。
在低肌肉激活和高肌肉激活两种条件下，活体犬半喉对抗玻璃棱镜发声。使用高速视频捕捉振动，3D 重建 VF 内侧表面纹身标志点的轨迹。采用经验特征函数法捕捉振动运动的基本动力学。对半喉进行组织学检查。
活体犬的振动模式与之前报道的离体人模型非常相似。两个最主要的本征函数占运动总方差的 90%以上，分别代表张开/闭合和会聚/发散的运动模式。我们在整个声门周期中观察到垂直相位差。在两种激活条件下，声带张开时，声带下部和上部之间的时间延迟大于声带闭合时。犬声带的组织学检查不仅显示了上部固有层较厚，而且还显示了与人类研究中描述的相似的杓状软骨肌纤维和束的模式。
尽管犬声带存在某些微观结构差异，但对其进行组织学和振动检查显示出了类似的人声带振动模式。本研究表明，多层固有层对于产生类似人声音的振动模式可能并非必需。
无（基础科学研究）喉镜，134：264-271，2024。
