Hirasugi Kaheita, Hisa Yasuo, Setsu Tomiyoshi, Terashima Toshio
Department of Otorhinolaryngology, Kyoto Prefectual School of Medicine, Kyoto, Japan.
Acta Otolaryngol. 2007 Feb;127(2):213-20. doi: 10.1080/00016480600794479.
The present study confirmed that ambiguus motoneurons innervating intrinsic laryngeal and esophageal muscles are radially malpositioned in the brainstem of the Shaking Rat Kawasaki (SRK), a reelin-deficient mutant rat.
Ambiguus motoneurons innervating the striated muscles of the larynx and esophagus take a long migration from their original birth plate in the floor of the fourth ventricle to their final settlement in the ventral margin of the medulla oblongata. To examine whether the migration of ambiguus nucleus neurons is affected in SRK, we studied localization of ambiguus motoneurons of postnatal day 21 (P21) normal and SRK rats.
To label ambiguus motoneurons retrogradely, horseradish peroxidase (HRP) was injected into some laryngeal muscles including cricothyroid, thyroarytenoid and posterior cricoarytenoid muscles, and the cervical and abdominal esophageal muscles of the SRK and normal controls 2 days before sacrifice.
In the P21 normal rat, HRP-positive laryngeal and esophageal motoneurons were found in the nucleus ambiguus, whereas in the P21 SRK, they were scattered from the base of the fourth ventricle to the ventro-lateral margin of the medulla, suggesting that radial migration of ambiguus motoneurons from their birthplace to their final settlement is guided by Reelin protein.
本研究证实，在瑞连蛋白缺乏的突变大鼠——摇晃小鼠川崎（SRK）的脑干中，支配喉内肌和食管肌的疑核运动神经元呈放射状位置异常。
支配喉和食管横纹肌的疑核运动神经元从其在第四脑室底部的原始生发板迁移至延髓腹侧边缘的最终位置，距离较远。为了研究SRK中疑核神经元的迁移是否受到影响，我们研究了出生后第21天（P21）正常和SRK大鼠疑核运动神经元的定位。
为了逆行标记疑核运动神经元，在处死前2天，将辣根过氧化物酶（HRP）注入SRK和正常对照大鼠的一些喉肌，包括环甲肌、甲杓肌和环杓后肌，以及颈段和腹段食管肌。
在P21正常大鼠中，HRP阳性的喉和食管运动神经元位于疑核中，而在P21 SRK大鼠中，它们从第四脑室底部散至延髓腹外侧边缘，这表明疑核运动神经元从其出生地到最终位置的放射状迁移受瑞连蛋白的引导。
