先天和适应性神经振荡模式中的性别差异将大鼠的抗压能力和易感性与慢性应激联系起来。
Sex differences in innate and adaptive neural oscillatory patterns link resilience and susceptibility to chronic stress in rats.
机构信息
From the department of Molecular and Cellular Biology, University of Guelph, Guelph, Ont., Canada (Thériault, Manduca, Perreault) and the Collaborative Neuroscience Program, University of Guelph, Guelph, Ont., Canada (Thériault, Perreault).
出版信息
J Psychiatry Neurosci. 2021 Mar 26;46(2):E258-E270. doi: 10.1503/jpn.200117.
BACKGROUND
Major depressive disorder is a chronic illness with a higher incidence in women. Dysregulated neural oscillatory activity is an emerging mechanism thought to underlie major depressive disorder, but whether sex differences in these rhythms contribute to the development of symptoms is unknown.
METHODS
We exposed male and female rats to chronic unpredictable stress and characterized them as stress-resilient or stress-susceptible based on behavioural output in the forced swim test and the sucrose preference test. To identify sex-specific neural oscillatory patterns associated with stress response, we recorded local field potentials from the prefrontal cortex, cingulate cortex, nucleus accumbens and dorsal hippocampus throughout stress exposure.
RESULTS
At baseline, female stress-resilient rats innately exhibited higher theta coherence in hippocampal connections compared with stress-susceptible female rats. Following stress exposure, additional oscillatory changes manifested: stress-resilient females were characterized by increased dorsal hippocampal theta power and cortical gamma power, and stress-resilient males were characterized by a widespread increase in high gamma coherence. In stress-susceptible animals, we observed a pattern of increased delta and reduced theta power; the changes were restricted to the cingulate cortex and dorsal hippocampus in males but occurred globally in females. Finally, stress exposure was accompanied by the time-dependent recruitment of specific neural pathways, which culminated in system-wide changes that temporally coincided with the onset of depression-like behaviour.
LIMITATIONS
We could not establish causality between the electrophysiological changes and behaviours with the methodology we employed.
CONCLUSION
Sex-specific neurophysiological patterns can function as early markers for stress vulnerability and the onset of depression-like behaviours in rats.
背景
重度抑郁症是一种慢性病，女性发病率较高。神经振荡活动失调是一种新兴的发病机制，被认为是重度抑郁症的基础，但这些节律是否存在性别差异，从而导致症状的发生尚不清楚。
方法
我们让雄性和雌性大鼠暴露于慢性不可预测的应激环境中，并根据它们在强迫游泳试验和蔗糖偏好试验中的行为表现，将它们分为应激抵抗或应激易感大鼠。为了确定与应激反应相关的性别特异性神经振荡模式，我们在整个应激暴露过程中记录了前额叶皮层、扣带回皮层、伏隔核和背侧海马体的局部场电位。
结果
在基线时，与应激易感的雌性大鼠相比，应激抵抗的雌性大鼠天生具有更高的海马连接theta 相干性。在应激暴露后，出现了其他的振荡变化：应激抵抗的雌性大鼠表现为背侧海马 theta 功率增加和皮质 gamma 功率增加，而应激抵抗的雄性大鼠则表现为广泛的高频 gamma 相干性增加。在应激易感动物中，我们观察到 delta 增加和 theta 减少的模式；这些变化仅发生在雄性动物的扣带回皮层和背侧海马体，而在雌性动物中则发生在全身。最后，应激暴露伴随着特定神经通路的时间依赖性募集，最终导致全系统的变化，这些变化与抑郁样行为的发生时间一致。
局限性
我们所采用的方法无法确定电生理变化与行为之间的因果关系。
结论
性别特异性神经生理模式可以作为大鼠应激易感性和抑郁样行为发生的早期标志物。
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