Nkomozepi Pilani, Mazengenya Pedzisai, Ihunwo Amadi O
School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa; Department of Human Anatomy & Physiology, University of Johannesburg, Cnr Siemert and Beit Streets, Doornfontein, Johannesburg, 2094, South Africa.
School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa.
Int J Dev Neurosci. 2019 May;74:38-48. doi: 10.1016/j.ijdevneu.2019.03.003. Epub 2019 Mar 16.
Most avian neurogenesis studies focused on the song control system and little attention has been given to non-song birds such as the Japanese quail. However, the only few neurogenesis studies in quails mainly focused on the sex steroid sensitive areas of the brain such as the medial preoptic and lateral septal nuclei. Despite the important role the quail telencephalon plays in filial imprinting and passive avoidance learning, neurogenesis in this structure has been completely overlooked. The aim of this study was therefore to quantitatively determine how DCX expression in the Japanese quail telencephalon changes with post hatching age (3-12 weeks) and life history stage. In this study, DCX was used as a proxy for neuronal incorporation. Bipolar and multipolar DCX immunoreactive cells were observed in the entire telencephalon except for the entopallium and arcopallium. In addition, DCX expression in all the eight telencephalic areas quantified was strongly negatively correlated with post-hatching age. Furthermore, numbers of bipolar and multipolar DCX immunoreactive cells were higher in the juvenile compared to subadult and adult quails. In conclusion, neuronal incorporation in the quail telencephalon is widespread but it declines with post hatching age. In addition, the most dramatic decline in neuronal incorporation in the telencephalic areas quantified takes place just after the birds have attained sexual maturity.
大多数鸟类神经发生的研究都集中在鸣唱控制系统，而对诸如日本鹌鹑等非鸣禽关注甚少。然而，鹌鹑中仅有的少数神经发生研究主要集中在大脑中对性类固醇敏感的区域，如内侧视前核和外侧隔核。尽管鹌鹑端脑在亲子印记和被动回避学习中发挥着重要作用，但该结构中的神经发生却完全被忽视了。因此，本研究的目的是定量确定日本鹌鹑端脑中双皮质素（DCX）的表达如何随孵化后年龄（3至12周）和生活史阶段而变化。在本研究中，DCX被用作神经元整合的替代指标。在整个端脑中观察到双极和多极DCX免疫反应性细胞，但在中脑旧皮质和新皮质除外。此外，在所有定量的八个端脑区域中，DCX的表达与孵化后年龄呈强烈负相关。此外，与亚成体和成年鹌鹑相比，幼鸟中双极和多极DCX免疫反应性细胞的数量更多。总之，鹌鹑端脑中的神经元整合广泛存在，但随孵化后年龄而下降。此外，在定量的端脑区域中，神经元整合最显著的下降发生在鸟类达到性成熟之后。
