Laboratory of Neurogenesis, Division of Clinical Research, National Institute of Psychiatry "Ramón de la Fuente Muñiz", Calzada México-Xochimilco 101, 14370 Mexico City, Mexico.
Neural Plast. 2018 May 22;2018:4960869. doi: 10.1155/2018/4960869. eCollection 2018.
Neurogenesis in the hippocampus is influenced by several factors including external stimuli. In addition to their involvement in learning and memory processes, newborn neurons of the dentate gyrus (DG) buffer against the effects of stress. Although the response of these cells to environmental stimuli has been shown, the age of the cells that respond to a brief spatial exploration or a stressful situation produced by forced-swim stress in adult female Balb/C mice is still unknown. Here, we investigated the activation of newborn neurons after three (IdU) or six weeks (CldU) postlabelling with the expression of Arc in the same mice but exposed to different environmental stimuli. Mice housed in standard conditions showed an increase in the activation of CldU-labelled cells after two exposures to a brief spatial exploration but no increase in the activation of IdU-labelled cells compared with the control group. Additionally, we analysed neuronal activation in the DG of mice housed in standard conditions and further exposed to forced-swim stress. We found a decreased activation of IdU-labelled cells in mice exposed to forced-swim stress with increase number of CldU-labelled cells. Our results suggest that based on their time postlabelling, newly generated hippocampal neurons show a different response to several environmental stimuli.
海马体中的神经发生受多种因素的影响，包括外部刺激。除了参与学习和记忆过程外，齿状回（DG）的新生神经元还能缓冲应激的影响。尽管已经证明了这些细胞对环境刺激的反应，但对于成年雌性 Balb/C 小鼠在短暂空间探索或强迫游泳应激产生的应激情况下，对短暂空间探索或应激情况做出反应的细胞的年龄仍不清楚。在这里，我们研究了在相同的小鼠中用 Arc 表达标记后 3（IdU）或 6 周（CldU）后，新生神经元的激活情况，同时这些小鼠暴露于不同的环境刺激。与对照组相比，在两次短暂空间探索暴露后，标准条件下饲养的小鼠中 CldU 标记细胞的激活增加，但 IdU 标记细胞的激活没有增加。此外，我们分析了标准条件下饲养的小鼠的 DG 中的神经元激活情况，以及进一步暴露于强迫游泳应激的情况。我们发现，暴露于强迫游泳应激的小鼠中 IdU 标记细胞的激活减少，而 CldU 标记细胞的数量增加。我们的结果表明，根据它们的标记后时间，新生成的海马神经元对多种环境刺激表现出不同的反应。
