Neuroscience Program, Wellesley College, 106 Central Street, Wellesley, MA 02481, USA.
Arthropod Struct Dev. 2011 May;40(3):258-75. doi: 10.1016/j.asd.2011.03.001. Epub 2011 Mar 9.
Defining evolutionary origins is a means of understanding an organism's position within the integrated web of living beings, and not only to trace characteristics back in time, but also to project forward in an attempt to reveal relationships with more recently evolved forms. Both the vertebrates and arthropods possess condensed nervous systems, but this is dorsal in the vertebrates and ventral in the arthropods. Also, whereas the nervous system in the vertebrates develops from a neural tube in the embryo, that of the arthropods comes from an ectodermal plate. Despite these apparently fundamental differences, it is now generally accepted that life-long neurogenesis, the generation of functionally integrated neurons from progenitor cells, is a common feature of the adult brains of a variety of organisms, ranging from insects and crustaceans to birds and mammals. Among decapod crustaceans, there is evidence for adult neurogenesis in basal species of the Dendrobranchiata, as well as in more recent terrestrial, marine and fresh-water species. The widespread nature of this phenomenon in decapod species may relate to the importance of the adult-born neurons, although their functional contribution is not yet known. The many similarities between the systems generating neurons in the adult brains of decapod crustaceans and mammals, reviewed in this paper, suggest that adult neurogenesis is governed by common ancestral mechanisms that have been retained in a phylogenetically broad group of species.
定义进化起源是理解生物体在生物整体网络中的位置的一种手段，不仅可以追溯特征的时间回溯，还可以预测未来，试图揭示与最近进化形式的关系。脊椎动物和节肢动物都具有浓缩的神经系统，但脊椎动物的神经系统是背侧的，而节肢动物的神经系统是腹侧的。此外，脊椎动物的神经系统是由胚胎中的神经管发育而来，而节肢动物的神经系统则来自外胚层板。尽管存在这些明显的根本差异，但现在普遍认为，从祖细胞产生功能上整合的神经元的终生神经发生是各种生物体成年大脑的共同特征，从昆虫和甲壳类动物到鸟类和哺乳动物。在十足甲壳动物中，有证据表明在 Dendrobranchiata 的基础物种以及最近的陆生、海洋和淡水物种中存在成年神经发生。这种现象在十足甲壳动物物种中的广泛存在可能与成年神经元的重要性有关，尽管它们的功能贡献尚不清楚。本文综述了十足甲壳动物成年大脑中产生神经元的系统之间的许多相似之处，表明成年神经发生受共同的祖先机制控制，这些机制在一个在系统发育上广泛的物种群体中得到保留。
