In adult hippocampal neurogenesis, stem/progenitor cells generate dentate granule neurons that contribute to hippocampal plasticity. The establishment of a morphologically defined dendritic arbor is central to the functional integration of adult‐born neurons. We investigated the role of canonical Wnt/β‐catenin signaling in dendritogenesis of adult‐born neurons. We show that canonical Wnt signaling follows a biphasic pattern, with high activity in stem/progenitor cells, attenuation in immature neurons, and reactivation during maturation, and demonstrate that this activity pattern is required for proper dendrite development. Increasing β‐catenin signaling in maturing neurons of young adult mice transiently accelerated dendritic growth, but eventually produced dendritic defects and excessive spine numbers. In middle‐aged mice, in which protracted dendrite and spine development were paralleled by lower canonical Wnt signaling activity, enhancement of β‐catenin signaling restored dendritic growth and spine formation to levels observed in young adult animals. Our data indicate that precise timing and strength of β‐catenin signaling are essential for the correct functional integration of adult‐born neurons and suggest Wnt/β‐catenin signaling as a pathway to ameliorate deficits in adult neurogenesis during aging.

中文翻译：

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β-catenin信号调节成年海马神经元树突生长的速度。

在成年海马神经发生中，干/祖细胞会产生齿状颗粒神经元，从而促进海马可塑性。形态学确定的树突状乔木的建立对于成年神经元功能整合至关重要。我们研究了经典的Wnt /β-catenin信号在成年神经元树突形成中的作用。我们显示规范的Wnt信号遵循双相模式，在干/祖细胞中具有高活性，在未成熟的神经元中衰减，并在成熟过程中重新激活，并证明该活性模式是适当的树突发育所必需的。年轻成年小鼠成熟神经元中β-catenin信号的增加会暂时促进树突状细胞的生长，但最终产生树突状缺陷和过多的脊柱数目。在中年小鼠中 其中延长的树突和脊柱发育与较低的经典Wnt信号传导活性并行，β-catenin信号增强使树突生长和脊柱形成恢复到成年成年动物中观察到的水平。我们的数据表明，β-catenin信号传导的精确时机和强度对于成人出生的神经元的正确功能整合至关重要，并建议Wnt /β-catenin信号作为缓解衰老过程中成人神经发生缺陷的途径。