School for Mental Health and Neuroscience, Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands.
Neuroscience. 2012 Dec 27;227:201-10. doi: 10.1016/j.neuroscience.2012.09.059. Epub 2012 Oct 2.
Pregnancy is a time of distinct neural, physiological and behavioral plasticity in the female. It is also a time when a growing number of women are vulnerable to stress and experience stress-related diseases, such as depression and anxiety. However, the impact of stress during gestation on the neurobiology of the mother has yet to be determined, particularly with regard to changes in the hippocampus; a brain area that plays an important role in stress-related diseases. Therefore, the aim of the present study was to understand how stress and reproductive state may alter dendritic morphology of CA1 and CA3 pyramidal neurons in the hippocampus. To do this, adult age-matched pregnant and virgin female Wistar rats were divided into two conditions: (1) control and (2) stress. Females in the stress condition were restrained for 1h/day for the last 2 weeks of gestation and at matched time-points in virgin females. Females were sacrificed the day after the last restraint session and brains were processed for Golgi impregnation. Dendritic length and number of branch points were quantified for apical and basal regions of CA1 and CA3 pyramidal neurons. Results show that regardless of reproductive state, stressed females had significantly shorter apical dendrites and fewer apical branch points in CA3 pyramidal cells. In addition, pregnant females, regardless of stress exposure, had less complex CA3 pyramidal neurons, as measured by Sholl analysis. No differences between conditions were seen in morphology of CA1 pyramidal neurons. This work shows that both repeated restraint stress and pregnancy affect dendritic morphology by decreasing complexity of CA3, but not CA1, neurons in the hippocampus.
妊娠是女性大脑神经、生理和行为发生显著可塑性的时期。也是越来越多的女性易受压力影响并出现与压力相关疾病（如抑郁和焦虑）的时期。然而，妊娠期压力对母体神经生物学的影响尚未确定，特别是在海马体中；海马体是与压力相关疾病相关的重要脑区。因此，本研究旨在了解压力和生殖状态如何改变海马体 CA1 和 CA3 锥体神经元的树突形态。为此，将成年同龄孕鼠和处女鼠分为两组：（1）对照组和（2）应激组。应激组的雌性在妊娠最后 2 周每天限制 1 小时，并在处女雌性的匹配时间点进行限制。雌性在最后一次限制后一天被处死，大脑进行高尔基染色。对 CA1 和 CA3 锥体神经元的顶树突和基底树突区域的长度和分支点数量进行量化。结果表明，无论生殖状态如何，应激雌性的 CA3 锥体神经元的顶树突明显缩短，顶树突分支点较少。此外，无论是否暴露于应激，怀孕雌性的 CA3 锥体神经元的形态也较为简单，通过 Sholl 分析得出。在 CA1 锥体神经元的形态上，各组之间没有差异。这项工作表明，反复束缚应激和妊娠都会通过降低 CA3 神经元的复杂性而影响树突形态，但不会影响 CA1 神经元。
