Behavioural consistency and hippocampal theta rhythm can reflect age-related anxiety during the behaviour test

Terry B J Kuo; Cheryl C H Yang; Chang-Tsen Hung; Chun-Hsiu Chen; Tsuo-Hung Lan; Jia-Yi Li

doi:10.1016/j.exger.2022.111808

Behavioural consistency and hippocampal theta rhythm can reflect age-related anxiety during the behaviour test

Exp Gerontol. 2022 Jun 15:163:111808. doi: 10.1016/j.exger.2022.111808. Epub 2022 Apr 14.

Authors

Terry B J Kuo¹, Cheryl C H Yang², Chang-Tsen Hung³, Chun-Hsiu Chen³, Tsuo-Hung Lan⁴, Jia-Yi Li⁵

Affiliations

¹ 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.
² 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.
³ Department of Health and Leisure Management, Yuanpei University of Medical Technology, Hsinchu, Taiwan.
⁴ Department of General Psychiatry, Tsaotun Psychiatric Center, Ministry of Health and Welfare, Nantou, Taiwan.
⁵ Sleep Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Health and Leisure Management, Yuanpei University of Medical Technology, Hsinchu, Taiwan. Electronic address: jyli@mail.ypu.edu.tw.

PMID: 35429591
DOI: 10.1016/j.exger.2022.111808

Abstract

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.

Keywords: Aging; Behavioural consistency; Elevated plus maze; Physical activity; Theta rhythm.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Anxiety
Anxiety Disorders
Behavior Rating Scale*
Hippocampus
Humans
Rats
Theta Rhythm*