Laboratory of Veterinary Anatomy, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
Tissue Cell. 2023 Aug;83:102130. doi: 10.1016/j.tice.2023.102130. Epub 2023 Jun 10.
The paratympanic organ (PTO) is a small sense organ in the middle ear of birds that contains hair cells similar to those found in vestibuloauditory organs and receives afferent fibers from the geniculate ganglion. To consider the histochemical similarities between the PTO and vestibular hair cells, we examined the expression patterns of representative molecules in vestibular hair cells, including prosaposin, G protein-coupled receptor (GPR) 37 and GPR37L1 as prosaposin receptors, vesicular glutamate transporter (vGluT) 2 and vGluT3, nicotinic acetylcholine receptor subunit α9 (nAChRα9), and glutamic acid decarboxylase (GAD) 65 and GAD67, in the postnatal day 0 chick PTO and geniculate ganglion by in situ hybridization. Prosaposin mRNA was observed in PTO hair cells, supporting cells, and geniculate ganglion cells. vGluT3 mRNA was observed in PTO hair cells, whereas vGluT2 was observed in a small number of ganglion cells. nAChRα9 mRNA was observed in a small number of PTO hair cells. The results suggest that the histochemical character of PTO hair cells is more similar to that of vestibular hair cells than that of auditory hair cells in chicks.
中耳旁器官（PTO）是鸟类中耳的一个小型感觉器官，其中包含与前庭听觉器官中发现的相似的毛细胞，并接收来自膝状神经节的传入纤维。为了研究 PTO 和前庭毛细胞之间的组织化学相似性，我们通过原位杂交检查了前庭毛细胞中代表性分子的表达模式，包括前脑啡肽原、G 蛋白偶联受体（GPR）37 和 GPR37L1 作为前脑啡肽原受体、囊泡谷氨酸转运体（vGluT）2 和 vGluT3、烟碱型乙酰胆碱受体亚基α9（nAChRα9）和谷氨酸脱羧酶（GAD）65 和 GAD67 在出生后 0 天小鸡 PTO 和膝状神经节中的表达模式。PTO 毛细胞、支持细胞和膝状神经节细胞中观察到前脑啡肽原 mRNA。vGluT3 mRNA 观察到在 PTO 毛细胞中，而 vGluT2 则在少数神经节细胞中观察到。nAChRα9 mRNA 观察到在少数 PTO 毛细胞中。结果表明，PTO 毛细胞的组织化学特征在小鸡中比听觉毛细胞更类似于前庭毛细胞。
