Planarian is among the simplest animals that possess a centralized nervous system (CNS), and its neural regeneration involves the replacement of cells lost to normal 'wear and tear' (cell turnover), and/or injury. In this review, we state and discuss the recent studies on molecular control of neural regeneration in planarians. The spatial and temporal expression patterns of genes in intact and regenerating planarian CNS have already been described relatively clearly. The bone morphogenetic protein (BMP) and Wnt signaling pathways are identified to regulate neural regeneration. During neural regeneration, conserved axon guidance mechanisms are necessary for proper wiring of the nervous system. In addition, apoptosis may play an important role in controlling cell numbers, eliminating unnecessary tissues or cells and remodeling the old tissues for regenerating CNS. The bilateral symmetry is established by determination of anterior-posterior (A-P) and dorsal-ventral (D-V) patterns. Moreover, neurons positive to dopamine, serotonin (5-HT), and gamma-aminobutyric acid (GABA) have been detected in planarians. Therefore, planarians present us with new, experimentally accessible contexts to study the molecular actions guiding neural regeneration.
涡虫是具有简单中枢神经系统的模式动物之一, 其神经再生过程包括受损细胞的替换以及细胞的再生过程。 本文阐述并讨论了近年来利用涡虫进行神经再生研究取得的研究进展。 目前, 参与涡虫神经再生相关基因的时空间表达图谱已被相对清晰地勾勒出来。 骨形成蛋白和Wnt信号通路已被鉴定参与神经再生的调控。 在神经再生过程中, 保守的轴突导向机制为神经系统网络的正确形成所必需。 此外, 细胞凋亡在控制细胞数量、 消除多余组织和细胞以及重新塑造再生的神经系统中发挥着重要作用。 而且, 在涡虫中多巴胺能神经元、 五羟色胺能神经元和γ-氨基丁酸能神经元可以被有效地予以标记。 因此, 涡虫为我们提供了一个可以在分子水平考察神经系统再生机制的新颖且具可操作性的实验研究平台。