Grupe Daniel W, Barnes Alexandra L, Gresham Lauren, Kirvin-Quamme Andrew, Nord Elizabeth, Alexander Andrew L, Abercrombie Heather C, Schaefer Stacey M, Davidson Richard J
University of Wisconsin-Madison Center for Healthy Minds, 625 W Washington Ave, Madison, WI, 53703, USA.
University of Wisconsin-Madison Waisman Laboratory for Brain Imaging and Behavior, 1500 Highland Ave, Madison, WI, 53705, USA.
Neurobiol Stress. 2022 Jul 8;19:100469. doi: 10.1016/j.ynstr.2022.100469. eCollection 2022 Jul.
Individual differences in stress appraisals influence trajectories of risk and resilience following exposure to chronic and acute stressors. Smaller hippocampal volume may contribute to elevated stress appraisals via deficient pattern separation, a process depending on dentate gyrus (DG)/CA3 hippocampal subfields. Here, we investigated links between perceived stress, DG/CA3 volume, and behavioral pattern separation to test hypothesized mechanisms underlying stress-related psychopathology.
We collected the Perceived Stress Scale (PSS) and ratings of subjective stress reactivity during the Trier Social Stress Test (TSST) from 71 adult community participants. We obtained high-resolution T2 MRI scans and used Automatic Segmentation of Hippocampal Subfields to estimate DG/CA3 volume in 56 of these participants. Participants completed the mnemonic similarity task, which provides a behavioral index of pattern separation. Analyses investigated associations between perceived stress, DG/CA3 volume, and behavioral pattern separation, controlling for age, gender, hemisphere, and intracranial volume.
Greater PSS scores and TSST subjective stress reactivity were each independently related to poorer behavioral pattern separation, together accounting for 15% of variance in behavioral performance in a simultaneous regression. Contrary to hypotheses, DG/CA3 volume was not associated with either stress measure, although exploratory analyses suggested a link between hippocampal volume asymmetry and PSS scores.
We observed novel associations between laboratory and questionnaire measures of perceived stress and a behavioral assay of pattern separation. Additional work is needed to clarify the involvement of the hippocampus in this stress-behavior relationship and determine the relevance of behavioral pattern separation for stress-related disorders.
压力评估中的个体差异会影响在暴露于慢性和急性应激源后风险和恢复力的轨迹。较小的海马体体积可能通过不足的模式分离导致压力评估升高，这一过程依赖于齿状回（DG）/海马体CA3亚区。在此，我们研究了感知压力、DG/CA3体积和行为模式分离之间的联系，以测试与压力相关的精神病理学潜在机制的假设。
我们从71名成年社区参与者中收集了感知压力量表（PSS）以及在特里尔社会压力测试（TSST）期间主观压力反应性的评分。我们获得了高分辨率T2 MRI扫描，并使用海马体亚区自动分割来估计其中56名参与者的DG/CA3体积。参与者完成了记忆相似性任务，该任务提供了模式分离的行为指标。分析研究了感知压力、DG/CA3体积和行为模式分离之间的关联，并控制了年龄、性别、半球和颅内体积。
较高的PSS分数和TSST主观压力反应性均与较差的行为模式分离独立相关，在同时回归中共同解释了行为表现中15%的方差。与假设相反，DG/CA3体积与任何一种压力测量均无关联，尽管探索性分析表明海马体体积不对称与PSS分数之间存在联系。
我们观察到实验室和问卷测量的感知压力与模式分离行为测定之间存在新的关联。需要进一步的研究来阐明海马体在这种压力与行为关系中的作用，并确定行为模式分离与压力相关障碍的相关性。
