Marchetta Philine, Eckert Philipp, Lukowski Robert, Ruth Peter, Singer Wibke, Rüttiger Lukas, Knipper Marlies
University of Tübingen, Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
University of Tübingen, Institute of Pharmacy, Pharmacology, Toxicology and Clinical Pharmacy, 72076 Tübingen, Germany.
iScience. 2022 Feb 26;25(3):103981. doi: 10.1016/j.isci.2022.103981. eCollection 2022 Mar 18.
The key auditory signature that may associate peripheral hearing with central auditory cognitive defects remains elusive. Suggesting the involvement of stress receptors, we here deleted the mineralocorticoid and glucocorticoid receptors ( and ) using a CaMKIIα-based tamoxifen-inducible Cre/ approach to generate mice with single or double deletion of central but not cochlear MR and GR. Hearing thresholds of MRGR conditional knockouts () were unchanged, whereas auditory nerve fiber () responses were larger and faster and auditory steady state responses were improved. Subsequent analysis of single MR or GR cKO revealed discrete roles for both, central MR and GR on cochlear functions. Limbic MR deletion reduced inner hair cell () ribbon numbers and ANF responses. In contrast, GR deletion shortened the latency and improved the synchronization to amplitude-modulated tones without affecting IHC ribbon numbers. These findings imply that stress hormone-dependent functions of central MR/GR contribute to "precognitive" sound processing in the cochlea.
可能将外周听力与中枢听觉认知缺陷联系起来的关键听觉特征仍然难以捉摸。鉴于应激受体的参与,我们在此使用基于CaMKIIα的他莫昔芬诱导型Cre/方法删除盐皮质激素和糖皮质激素受体(MR和GR),以生成中枢而非耳蜗的MR和GR单缺失或双缺失的小鼠。MRGR条件性敲除小鼠(MRGR cKO)的听力阈值未发生变化,而听神经纤维(ANF)反应更大、更快,听觉稳态反应得到改善。随后对单个MR或GR cKO的分析揭示了中枢MR和GR在耳蜗功能上的不同作用。边缘系统MR缺失减少了内毛细胞(IHC)的突触小体数量和ANF反应。相比之下,GR缺失缩短了潜伏期并改善了对调幅音的同步性,而不影响IHC突触小体数量。这些发现表明,中枢MR/GR的应激激素依赖性功能有助于耳蜗中的“认知前”声音处理。