Chehrehasa Fatemeh, Jacques Angela, St John James A, Ekberg Jenny A K
School of Biomedical Sciences, Queensland University of Technology, Box 2434, QLD 4001, Australia; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, 170 Kessels Rd, Nathan 4111, Australia.
School of Biomedical Sciences, Queensland University of Technology, Box 2434, QLD 4001, Australia.
Brain Res. 2018 Jun 1;1688:65-72. doi: 10.1016/j.brainres.2018.03.020. Epub 2018 Mar 20.
The Grueneberg organ (also termed Grueneberg ganglion) is an olfactory subsystem at the rostral nasal septum of rodents, and has been suggested to exist also in humans. Grueneberg organ neurons respond to coldness and alarm pheromones, but the anatomical arrangement and regenerative capacity are not fully characterised. We examined the relationship between the glia and the neurons using crosses of two transgenic mouse lines, S100ß-DsRed and OMP-ZsGreen, to visualise olfactory ensheathing cells (OECs) and Grueneberg olfactory neurons, respectively. Within the epithelium, Grueneberg organ OECs were in direct contact with Grueneberg organ neuron cell bodies. Individual axons from the neurons initially grew over the surface of the OECs before forming larger fascicles consisting of numerous axons and OECs. Considering the location of the Grueneberg organ so close to the external environment, it may be that the Grueneberg neurons are likely to be subject to damage suggesting that as in other olfactory regions there is a capacity for recovery after injury. Here, we used a well characterised model of olfactory nervous system injury, unilateral bulbectomy, to determine whether Grueneberg organ neurons degenerate after injury. We found that Grueneberg organ neurons degenerated in response to the axotomy, yet by 11 days post injury neurons and/or axons were detected again within the epithelium. Our results demonstrate that while Grueneberg organ neurons and glia have a distinct relationship in the epithelium, they have largely similar characteristics to that of the main olfactory neurons and glia.
格鲁内贝格器官（也称为格鲁内贝格神经节）是啮齿动物鼻前部鼻中隔处的一个嗅觉子系统，也有人认为人类中也存在该器官。格鲁内贝格器官神经元对寒冷和警报信息素产生反应，但其解剖结构和再生能力尚未完全明确。我们使用两种转基因小鼠品系S100β-DsRed和OMP-ZsGreen的杂交，分别观察嗅鞘细胞（OECs）和格鲁内贝格嗅觉神经元，以此来研究神经胶质细胞与神经元之间的关系。在该上皮组织内，格鲁内贝格器官的嗅鞘细胞与格鲁内贝格器官神经元的细胞体直接接触。神经元的单个轴突最初在嗅鞘细胞表面生长，之后形成由众多轴突和嗅鞘细胞组成的更大的束。鉴于格鲁内贝格器官的位置非常靠近外部环境，格鲁内贝格神经元可能容易受到损伤，这表明与其他嗅觉区域一样，损伤后具有恢复能力。在这里，我们使用一种特征明确的嗅觉神经系统损伤模型——单侧嗅球切除术，来确定格鲁内贝格器官神经元在损伤后是否会退化。我们发现，格鲁内贝格器官神经元会因轴突切断而退化，但在损伤后11天，上皮组织内又再次检测到神经元和/或轴突。我们的结果表明，虽然格鲁内贝格器官神经元和神经胶质细胞在上皮组织中有明显不同的关系，但它们在很大程度上与主要嗅觉神经元和神经胶质细胞具有相似的特征。
