Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.
Science. 2020 Jun 26;368(6498). doi: 10.1126/science.aba3203.
Neuronal circuits damaged or lost after injury can be regenerated in some adult organisms, but the mechanisms enabling this process are largely unknown. We used the planarian to study visual system regeneration after injury. We identify a rare population of muscle cells tightly associated with photoreceptor axons at stereotyped positions in both uninjured and regenerating animals. Together with a neuronal population, these cells promote de novo assembly of the visual system in diverse injury and eye transplantation contexts. These muscle guidepost-like cells are specified independently of eyes, and their position is defined by an extrinsic array of positional information cues. These findings provide a mechanism, involving adult formation of guidepost-like cells typically observed in embryos, for axon pattern restoration in regeneration.
神经元回路在损伤后可以在一些成年生物中再生，但这一过程的机制在很大程度上尚不清楚。我们利用扁形动物研究了损伤后的视觉系统再生。我们在未受伤和再生动物中都发现了一个罕见的肌肉细胞群体，它们与光感受器轴突紧密相关，位于特定的位置。这些细胞与神经元群体一起，在不同的损伤和眼球移植环境中促进视觉系统的重新组装。这些类似引导桩的细胞是独立于眼睛而特化的，其位置由一个外在的位置信息线索数组定义。这些发现提供了一种机制，涉及到通常在胚胎中观察到的成年形成的引导桩样细胞，用于再生中的轴突模式恢复。
