College of Medicine, Ajman University, Ajman, United Arab Emirates.
School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Int J Dev Neurosci. 2020 Nov;80(7):613-635. doi: 10.1002/jdn.10057. Epub 2020 Aug 26.
In the current study, we examined adult neurogenesis throughout the brain of the common ostrich (Struthio camelus) and emu (Dromaius novaehollandiae) using immunohistochemistry for the endogenous markers PCNA which labels proliferating cells, and DCX, which stains immature and migrating neurons. The distribution of PCNA and DCX labelled cells was widespread throughout the brain of both species. The highest density of cells immunoreactive to both markers was observed in the olfactory bulbs and the telencephalon, especially the subventricular zone of the lateral ventricle. Proliferative hot spots, identified with strong PCNA and DCX immunolabelling, were identified in the dorsal and ventral poles of the rostral aspects of the lateral ventricles. The density of PCNA immunoreactive cells was less in the telencephalon of the emu compared to the common ostrich. Substantial numbers of PCNA immunoreactive cells were observed in the diencephalon and brainstem, but DCX immunoreactivity was weaker in these regions, preferentially staining axons and dendrites over cell bodies, except in the medial regions of the hypothalamus where distinct DCX immunoreactive cells and fibres were observed. PCNA and DCX immunoreactive cells were readily observed in moderate density in the cortical layers of the cerebellum of both species. The distribution of putative proliferating cells and immature neurons in the brain of the common ostrich and the emu is widespread, far more so than in mammals, and compares with the neognathous birds, and suggests that brain plasticity and neuronal turnover is an important aspect of cognitive brain functions in these birds.
在本研究中，我们使用增殖细胞核抗原（PCNA）和双皮质素（DCX）这两种内源性标志物的免疫组织化学方法，检测了普通鸵鸟（Struthio camelus）和鸸鹋（Dromaius novaehollandiae）大脑中的成年神经发生。PCNA 标记增殖细胞，而 DCX 则标记未成熟和迁移的神经元。PCNA 和 DCX 标记细胞在两种物种的大脑中广泛分布。两种标志物均呈阳性的细胞密度最高的区域位于嗅球和端脑，特别是侧脑室的室下区。在侧脑室头端的背侧和腹侧极，观察到具有强烈 PCNA 和 DCX 免疫染色的增殖热点。与普通鸵鸟相比，鸸鹋端脑中 PCNA 阳性细胞的密度较低。在间脑和脑干中观察到大量的 PCNA 阳性细胞，但这些区域的 DCX 免疫反应性较弱，优先对轴突和树突进行染色，而不是对细胞体进行染色，但在下丘脑的内侧区域除外，在那里观察到明显的 DCX 阳性细胞和纤维。PCNA 和 DCX 阳性细胞在两种物种的小脑皮质层中以中等密度容易观察到。普通鸵鸟和鸸鹋大脑中增殖细胞和未成熟神经元的分布非常广泛，远超过哺乳动物，与新颌鸟类相似，这表明大脑可塑性和神经元更替是这些鸟类认知脑功能的一个重要方面。
