Kuo Terry B J, Yang Cheryl C H, Hung Chang-Tsen, Chen Chun-Hsiu, Lan Tsuo-Hung, Li Jia-Yi
Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, Taiwan; Sleep Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan; Clinical Research Center, Taoyuan Psychiatric Center, Ministry of Health and Welfare, Taoyuan, Taiwan.
Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, Taiwan; Sleep Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan; Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Exp Gerontol. 2022 Jun 15;163:111808. doi: 10.1016/j.exger.2022.111808. Epub 2022 Apr 14.
It is known that anxiety has a lot of comorbidity such as depression and may cause older subjects to be more prone to anxiety. Animal studies have also observed that older rats have lower movement in different situations, somewhat like anxiety symptoms (avoidance and freezing). The anxiety level of rodents is commonly evaluated using the elevated plus maze test, and videos are often used to record and quantify the activities of animals during the test. Furthermore, aging can reduce the frequency and activity of locomotion-induced hippocampal theta rhythm, and these reductions are also reflected in sensory-motor integration and cognition. Thus, directly analyzing the hippocampal theta rhythm and the quantity and quality of physical activity (PA) during the anxiety test can help elucidate the mechanisms underlying the anxiety-like behaviour. We explored alterations in the hippocampal theta rhythm, PA, and behavioural consistency (cross-correlation with 8-s window length) from triaxial acceleration vectors and subsequently examined the effects of age during the elevated plus maze test. We hypothesized that middle-aged rats would exhibit more anxiety, which is correlated with a reduction in behavioural consistency and hippocampal theta frequency during the elevated plus maze test. The middle-aged rats had a lower open-arm frequency and more low-frequency theta oscillations. The middle-aged rats had a lower mean power frequency (Frq) of the hippocampal theta rhythm, PA, and behavioural consistency. The Frq of the middle-aged rats was positively correlated with behavioural consistency. The results indicated that behavioural consistency could distinguish age-related anxiety-like behaviour. Behavioural consistency can serve as an index for the quality of movement and be used to distinguish age-related anxiety.
众所周知，焦虑有许多共病情况，如抑郁，并且可能使老年受试者更容易出现焦虑。动物研究也观察到，老年大鼠在不同情况下活动较少，有点类似于焦虑症状（回避和僵住）。啮齿动物的焦虑水平通常使用高架十字迷宫试验来评估，并且在试验过程中常使用视频来记录和量化动物的活动。此外，衰老会降低运动诱导的海马θ节律的频率和活动，并且这些降低也反映在感觉运动整合和认知方面。因此，在焦虑测试期间直接分析海马θ节律以及身体活动（PA）的数量和质量，有助于阐明类似焦虑行为背后的机制。我们从三轴加速度矢量中探索了海马θ节律、PA和行为一致性（与8秒窗口长度的互相关）的变化，随后在高架十字迷宫试验中研究了年龄的影响。我们假设中年大鼠会表现出更多焦虑，这与高架十字迷宫试验期间行为一致性降低和海马θ频率降低相关。中年大鼠的开放臂频率较低，低频θ振荡较多。中年大鼠海马θ节律、PA和行为一致性的平均功率频率（Frq）较低。中年大鼠的Frq与行为一致性呈正相关。结果表明，行为一致性可以区分与年龄相关的类似焦虑行为。行为一致性可以作为运动质量的指标，并用于区分与年龄相关的焦虑。
