Matsunaga Daisuke, Nakagawa Hikaru, Ishiwata Takayuki
Department of Health-Promotion and Sports Science, Osaka Electro-Communication University, 1130-70 Kiyotaki, Shijonawate-shi, Osaka 575-0063, Japan; Graduate School of Community & Human Services, Rikkyo University, 1-2-26 Kitano, Niiza, Saitama 352-8558, Japan.
College of Sport &Wellness, Rikkyo University, 1-2-26 Kitano, Niiza, Saitama 352-8558, Japan.
Behav Brain Res. 2025 Feb 28;479:115321. doi: 10.1016/j.bbr.2024.115321. Epub 2024 Nov 6.
Physical exercise improves physical and mental health; however, the differences between voluntary and forced exercise protocols are unclear. In addition, knowledge regarding the consequences of differences in testing timing, such as light and dark phases, in response to exercise type is limited. We investigated the effects of chronic forced and voluntary wheel running on the changes in brain monoamine levels (5-HT: serotonin, DA: dopamine, NA: noradrenaline), anxiety-like behaviours, and physiological stress responses in the light and dark phases.
Adult male Wistar rats were equally and randomly assigned to four groups: sedentary control, voluntary exercise (free running on a wheel, V-EX), voluntary limited exercise (wheel available only 1 h/day, VL-EX), and forced exercise (running on a motorised wheel, F-EX). Each group was further divided into dark- or light-experimental condition groups. After 4 weeks, the rats underwent an open-field test. The monoamines and their metabolite levels were measured in the major neural cell bodies and the projection areas related to behaviour, cognition, anxiety, and stress in the brain.
Adrenal hypertrophy and elevated body temperature, except during the exercise period, were observed in the F-EX rats that exhibited anxiety-like behaviour. The levels of monoamines and their metabolites, particularly the 5-HTergic and DAergic systems, in specific areas, were significantly altered in the rats in the V-EX group compared to those in the VL-EX and other groups. These differences were observed only in the dark phase.
The results suggest that V-EX mainly stimulates the 5-HTergic and DAergic systems, while F-EX induces physiological stress and increases anxiety-like behaviour during the dark phase. This study highlights the importance of accounting for exercise types and light/dark phases in behavioural neuroscience experiments.
体育锻炼可改善身心健康；然而，自愿运动方案和强迫运动方案之间的差异尚不清楚。此外，关于不同测试时间（如明相和暗相）对运动类型反应的差异所产生后果的了解有限。我们研究了长期强迫性和自愿性轮转跑步对明相和暗相大脑单胺水平（5-羟色胺：血清素，多巴胺：DA，去甲肾上腺素：NA）变化、焦虑样行为和生理应激反应的影响。
成年雄性Wistar大鼠被平均随机分为四组：久坐对照组、自愿运动组（在轮子上自由奔跑，V-EX）、自愿有限运动组（每天仅1小时可使用轮子，VL-EX）和强迫运动组（在电动轮子上跑步，F-EX）。每组进一步分为暗相或明相实验条件组。4周后，对大鼠进行旷场试验。在大脑中与行为、认知、焦虑和应激相关的主要神经细胞体和投射区域测量单胺及其代谢物水平。
在表现出焦虑样行为的F-EX大鼠中，除运动期间外，观察到肾上腺肥大和体温升高。与VL-EX组和其他组相比，V-EX组大鼠特定区域的单胺及其代谢物水平，特别是5-羟色胺能和多巴胺能系统，发生了显著变化。这些差异仅在暗相中观察到。
结果表明，V-EX主要刺激5-羟色胺能和多巴胺能系统，而F-EX在暗相期间诱导生理应激并增加焦虑样行为。本研究强调了在行为神经科学实验中考虑运动类型和明/暗相的重要性。
