Kinoshita Shota, Sugiyama Yoichiro, Hashimoto Keiko, Fuse Shinya, Mukudai Shigeyuki, Umezaki Toshiro, Dutschmann Mathias, Hirano Shigeru
Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Department of Speech and Hearing Sciences, International University of Health and Welfare, and the Voice and Swallowing Center, Fukuoka Sanno Hospital, Fukuoka, Japan.
Laryngoscope. 2021 Oct;131(10):2187-2198. doi: 10.1002/lary.29242. Epub 2020 Nov 4.
We aimed to examine the effect of unilateral inhibition of the medullary dorsal swallowing networks on the activities of swallowing-related cranial motor nerves and swallowing interneurons.
In 25 juvenile rats, we recorded bilateral vagal nerve activity (VNA) as well as unilateral phrenic and hypoglossal activity (HNA) during fictive swallowing elicited by electrical stimulation of the superior laryngeal nerve during control and following microinjection of the GABA agonist muscimol into the caudal dorsal medulla oblongata in a perfused brainstem preparation. In 20 animals, swallowing interneurons contralateral to the muscimol injection side were simultaneously recorded extracellularly and their firing rates were analyzed during swallowing.
Integrated VNA and HNA to the injection side decreased to 49.0 ± 16.6% and 32.3 ± 17.9%, respectively. However, the VNA on the uninjected side showed little change after muscimol injection. Following local inhibition, 11 out of 20 contralateral swallowing interneurons showed either increased or decreased of their respective firing discharge during evoked-swallowing, while no significant changes in activity were observed in the remaining nine neurons.
The neuronal networks underlying the swallowing pattern generation in the dorsal medulla mediate the ipsilateral motor outputs and modulate the contralateral activity of swallowing interneurons, suggesting that the bilateral coordination of the swallowing central pattern generator regulates the spatiotemporal organization of pharyngeal swallowing movements.
NA Laryngoscope, 131:2187-2198, 2021.
我们旨在研究单侧抑制延髓背侧吞咽网络对吞咽相关颅运动神经和吞咽中间神经元活动的影响。
在25只幼年大鼠中，我们在灌注脑干标本中，于对照期间以及向尾侧延髓背侧微量注射GABA激动剂蝇蕈醇后，通过电刺激喉上神经诱发假吞咽时，记录双侧迷走神经活动（VNA）以及单侧膈神经和舌下神经活动（HNA）。在20只动物中，同时细胞外记录蝇蕈醇注射侧对侧的吞咽中间神经元，并在吞咽期间分析其放电频率。
注射侧的VNA和HNA积分分别降至49.0±16.6%和32.3±17.9%。然而，注射蝇蕈醇后未注射侧的VNA几乎没有变化。局部抑制后，20个对侧吞咽中间神经元中有11个在诱发吞咽期间其各自的放电频率增加或减少，而其余9个神经元的活动未观察到显著变化。
延髓背侧吞咽模式产生的神经网络介导同侧运动输出并调节对侧吞咽中间神经元的活动，这表明吞咽中枢模式发生器的双侧协调调节咽部吞咽运动的时空组织。
NA 《喉镜》，131:2187 - 2198，2021年。
