From the Department of Psychology (Normann, McNeal, Dagner, Ihm, Woodbury, Grippo), Northern Illinois University, DeKalb, Illinois; Expeditionary and Trauma Medicine Naval Medical Research Unit (McNeal), JBSA-Ft, Sam Houston, Texas; and Department of Psychological and Brain Sciences (Ihm), University of California, Santa Barbara, California.
Psychosom Med. 2018 Apr;80(3):271-277. doi: 10.1097/PSY.0000000000000558.
Stress is linked to negative cardiovascular consequences and increases in depressive behaviors. Environmental enrichment (EE) involves exposure to novel items that provide physical and cognitive stimulation. EE has behavioral, cognitive, and neurobiological effects that may improve stress responses in humans and animal models. This study investigated the potential protective effects of EE on behavior and cardiovascular function in female prairie voles after a social stressor.
Radiotelemetry transmitters were implanted into female prairie voles to measure heart rate (HR) and heart rate variability (HRV) throughout the study. All females were paired with a male partner for 5 days, followed by separation from their partner for 5 additional days, and a 10-day treatment period. Treatment consisted of continued isolation, isolation with EE, or re-pairing with the partner (n = 9 per group). After treatment, animals were observed in the forced swim test (FST) for measures of stress coping behaviors.
Isolation elevated HR and reduced HRV relative to baseline for all groups (p < .001). HR and HRV returned to baseline in the EE and re-paired groups, but not in the continued isolation group (p < .001). Animals in the EE and re-paired groups displayed significantly lower immobility time (p < .001) and HR (p < .03) during the FST, with a shorter latency for HR to return to baseline levels after the FST, relative to the continued isolation group (p < .001).
EE and re-pairing reversed the negative behavioral and cardiovascular consequences associated with social isolation.
压力与负面心血管后果和抑郁行为增加有关。环境丰富（EE）涉及接触新的物品，提供身体和认知刺激。EE 具有行为、认知和神经生物学效应，可能改善人类和动物模型的应激反应。本研究调查了 EE 在社会应激源后对雌性草原田鼠行为和心血管功能的潜在保护作用。
放射性遥测发射器被植入雌性草原田鼠体内，以在整个研究过程中测量心率（HR）和心率变异性（HRV）。所有雌性动物都与雄性伴侣配对 5 天，然后与伴侣分离 5 天，再进行 10 天的治疗期。治疗包括继续隔离、隔离与 EE 或与伴侣重新配对（每组 9 只）。治疗后，动物在强迫游泳试验（FST）中观察应激应对行为。
与基线相比，隔离使所有组的 HR 升高，HRV 降低（p <.001）。EE 和重新配对组的 HR 和 HRV 恢复到基线，但继续隔离组没有（p <.001）。EE 和重新配对组的动物在 FST 中表现出明显较低的不动时间（p <.001）和 HR（p <.03），并且在 FST 后 HR 恢复到基线水平的潜伏期更短，与继续隔离组相比（p <.001）。
EE 和重新配对逆转了与社会隔离相关的负面行为和心血管后果。
