Department of Biology, University of Maryland, College Park, MD 20742, USA.
Department of Biology, University of Maryland, College Park, MD 20742, USA.
Curr Biol. 2024 Nov 4;34(21):4908-4919.e3. doi: 10.1016/j.cub.2024.09.016. Epub 2024 Oct 4.
Otolithic endorgans such as the saccule were thought to be strictly vestibular in amniotes (reptiles, birds, and mammals), with little evidence supporting the auditory function found in fish and amphibians (frogs and salamanders). Here, we demonstrate an auditory role for the saccule in the tokay gecko (Gekko gecko). The nucleus vestibularis ovalis (VeO) in the hindbrain exclusively receives input from the saccule and projects to the auditory midbrain, the torus semicircularis, via an ascending pathway parallel to cochlear pathways. Single-unit recordings show that VeO is exquisitely sensitive to low-frequency vibrations. Moreover, VeO is present in other lepidosaurs, including snakes and Sphenodon. These findings indicate that the ancestral auditory function of the saccule is likely preserved at least in the lepidosaurian lineage of amniotes and mediates sensitive encoding of vibration. VIDEO ABSTRACT.
耳石末端器官，如囊斑，被认为在羊膜动物（爬行动物、鸟类和哺乳动物）中是严格的前庭器官，只有很少的证据支持鱼类和两栖动物（青蛙和蝾螈）中发现的听觉功能。在这里，我们证明了囊斑在壁虎（Gekko gecko）中的听觉作用。后脑的前庭神经椭圆核（VeO）仅接收来自囊斑的输入，并通过与耳蜗途径平行的上升途径投射到听觉中脑，即半规管。单细胞记录显示，VeO 对低频振动极其敏感。此外，VeO 也存在于其他蜥蜴目动物中，包括蛇和楔齿蜥。这些发现表明，囊斑的祖先听觉功能至少在羊膜动物的蜥蜴目中得以保留，并介导了对振动的敏感编码。视频摘要。
