Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany.
Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany.
Stem Cell Reports. 2020 Dec 8;15(6):1333-1346. doi: 10.1016/j.stemcr.2020.10.010. Epub 2020 Nov 19.
The rodent olfactory bulb (OB) is continuously supplied with adult-born cells maturing into GABAergic neurons. Using in vivo ratiometric Ca imaging to readout ongoing and sensory-driven activity, we asked whether mature adult-born cells (mABCs) in the glomerular layer of the bulb become functionally identical to resident GABAergic (Res) neurons. In awake head-restrained mice the two cell populations differed significantly in terms of ongoing spontaneous activity, with 24% of mABCs contributing to a strongly active cell cluster, absent among Res cells. Odor-evoked responses of mABCs were sparse, less reliable, and had smaller amplitudes compared with Res cells. The opposite was seen under anesthesia, with response reliability increasing and response size of mABCs becoming larger than that of Res cells. Furthermore, ongoing activity of mABCs showed increased sensitivity to ketamine/xylazine and was selectively blocked by the antagonist of serotonin receptors methysergide. These functional features of mABCs clearly distinguish them from other OB interneurons.
啮齿动物嗅球（OB）不断供应成熟为 GABA 能神经元的成年新生细胞。我们使用体内比率 Ca2+ 成像来读取持续和感觉驱动的活动，以询问嗅球颗粒层中的成熟成年新生细胞（mABC）是否在功能上与常驻 GABA 能（Res）神经元相同。在清醒的头部固定的小鼠中，这两种细胞群在持续自发活动方面存在显著差异，24%的 mABC 参与了一个强烈活跃的细胞群，而 Res 细胞中不存在这种细胞群。与 Res 细胞相比，mABC 的气味诱发反应稀疏、不可靠且幅度较小。在麻醉下则相反，mABC 的反应可靠性增加，反应幅度大于 Res 细胞。此外，mABC 的持续活动对氯胺酮/甲苯噻嗪的敏感性增加，并且被 5-羟色胺受体拮抗剂甲麦角林选择性阻断。mABC 的这些功能特征将它们与其他 OB 中间神经元明显区分开来。
