Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Cumming School of Medicine, HMRB 162, Health Sciences Centre, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
Sci Rep. 2022 Apr 29;12(1):7016. doi: 10.1038/s41598-022-10947-w.
Postnatal hippocampal neurogenesis has been demonstrated to affect learning and memory in numerous ways. Several studies have now demonstrated that increased neurogenesis can induce forgetting of memories acquired prior to the manipulation of neurogenesis and, as a result of this forgetting can also facilitate new learning. However, the mechanisms mediating neurogenesis-induced forgetting are not well understood. Here, we used a subregion-based analysis of the immediate early gene c-Fos as well as in vivo fiber photometry to determine changes in activity corresponding with neurogenesis induced forgetting. We found that increasing neurogenesis led to reduced CA1 activity during context memory retrieval. We also demonstrate here that perineuronal net expression in areas CA1 is bidirectionally altered by the levels or activity of postnatally generated neurons in the dentate gyrus. These results suggest that neurogenesis may induce forgetting by disrupting perineuronal nets in CA1 which may otherwise protect memories from degradation.
产后海马神经发生已被证明以多种方式影响学习和记忆。现在有几项研究表明，增加神经发生会导致对神经发生操作之前获得的记忆的遗忘，并且由于这种遗忘，也可以促进新的学习。然而，介导神经发生诱导遗忘的机制尚不清楚。在这里，我们使用即时早期基因 c-Fos 的基于亚区的分析以及体内光纤光度法来确定与神经发生诱导遗忘相对应的活性变化。我们发现，增加神经发生会导致在上下文记忆检索过程中 CA1 活性降低。我们还在这里证明，在齿状回中产生的新生神经元的水平或活性的双向改变了 CA1 中的神经周围网络的表达。这些结果表明，神经发生可能通过破坏 CA1 中的神经周围网络来诱导遗忘，否则这些网络可能会保护记忆免受降解。
