Abbink M R, Naninck E F G, Lucassen P J, Korosi A
Swammerdam Institute for Life Sciences, Center for Neuroscience, Brain plasticity group, University of Amsterdam, Amsterdam, The Netherlands.
Hippocampus. 2017 Aug;27(8):839-844. doi: 10.1002/hipo.22745. Epub 2017 Jun 6.
Exposure to early-life stress (ES) has long-lasting consequences for later cognition and hippocampal plasticity, including adult hippocampal neurogenesis (AHN), i.e., the generation of new neurons from stem/progenitor cells in the adult hippocampal dentate gyrus. We had previously demonstrated a sex-specific vulnerability to ES exposure; female mice exposed to ES from P2-P9 exhibited only very mild cognitive changes and no reductions in AHN as adult, whereas ES-exposed male mice showed impaired cognition closely associated with reductions in AHN. Given the apparent resilience of AHN to ES in females, we here questioned whether ES has also altered the capacity to respond to positive stimuli for neurogenesis. We therefore investigated whether exercise, known for its strong pro-neurogenic effects, can still stimulate AHN in adult female mice that had been earlier exposed to ES. We confirm a strong pro-neurogenic effect of exercise in the dorsal hippocampus of 8-month-old control female mice, but this positive neurogenic response is less apparent in female ES mice. These data provide novel insights in the lasting consequences of ES on hippocampal plasticity in females and also indicate that ES might lastingly reduce the responsiveness of the hippocampal stem cell pool, to exercise, in female mice.
早年应激（ES）暴露对后期认知和海马可塑性具有长期影响，包括成年海马神经发生（AHN），即成年海马齿状回中由干细胞/祖细胞产生新神经元的过程。我们之前已经证明了ES暴露存在性别特异性易感性；从出生后第2天到第9天暴露于ES的雌性小鼠仅表现出非常轻微的认知变化，成年后AHN没有减少，而暴露于ES的雄性小鼠则表现出与AHN减少密切相关的认知障碍。鉴于雌性小鼠AHN对ES具有明显的恢复力，我们在此质疑ES是否也改变了对神经发生的积极刺激的反应能力。因此，我们研究了以其强大的促神经发生作用而闻名的运动，是否仍能刺激早期暴露于ES的成年雌性小鼠的AHN。我们证实运动对8个月大的对照雌性小鼠的背侧海马具有强大的促神经发生作用，但这种积极的神经发生反应在雌性ES小鼠中不太明显。这些数据为ES对雌性海马可塑性的长期影响提供了新的见解，也表明ES可能会持久降低雌性小鼠海马干细胞池对运动的反应性。
