The dentate gyrus (DG) of the hippocampus is fundamental for cognitive flexibility and has the extraordinary ability to generate new neurons throughout life. Recent evidence suggested that adult-born neurons differentially modulate input to the DG during the processing of spatial information and novelty. However, how this differential regulation by neurogenesis is translated into different aspects contributing cognitive flexibility is unclear. Here, we increased adult-born neurons by a genetic expansion of neural stem cells and studied their influence during navigational learning. We found that increased neurogenesis improved memory precision, indexing and retention and that each of these gains was associated with a differential activation of specific DG compartments and better separation of memory representations in the DG-CA3 network. Our results highlight the role of adult-born neurons in promoting memory precision in the infrapyramidal and indexing in the suprapyramidal blade of the DG and together contributing to cognitive flexibility.

中文翻译：

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成人出生的神经元通过提高记忆精度和索引来促进认知灵活性

海马的齿状回（DG）是认知灵活性的基础，并且具有在整个生命中产生新神经元的非凡能力。最近的证据表明，在处理空间信息和新颖性期间，成年出生的神经元会差异地调节对DG的输入。但是，尚不清楚如何将这种由神经发生引起的差异调节转化为有助于认知灵活性的不同方面。在这里，我们通过神经干细胞的基因扩增增加了成年出生的神经元，并研究了它们在导航学习中的影响。我们发现增加的神经发生改善了记忆的精确度，索引编制和保留，并且这些增益中的每一个都与特定DG间隔的差异激活和DG-CA3网络中记忆表示的更好分离有关。