Physical exercise is beneficial to both physical and mental health, though it is unclear whether voluntary and forced exercise have the same effects. We investigated the effects of chronic forced and voluntary wheel running on brain levels of serotonin (5-HT), its metabolite 5-hydroxyindoleacetic acid (5-HIAA), and anxiety-like behavioral change in rats. Forty-eight rats were randomly assigned to standard cages (sedentary control: SC); voluntary exercise (free running on a wheel, V-EX); voluntary limited exercise (wheel available only 1 h per day, VL-EX); and forced exercise (running on a motorized wheel, F-EX). After 4 weeks, rats either underwent the open field test (OFT) or their 5-HT and 5-HIAA levels were measured in the major serotonergic neural cell bodies and projection areas. 5-HT and 5-HIAA levels in the dorsal and median raphe nuclei were increased in the V-EX, but not in the VL-EX and F-EX groups, compared with the SC group. In the paraventricular hypothalamic nucleus and caudate putamen, only 5-HT levels were increased in the V-EX group. Interestingly, in the amygdala, only 5-HIAA levels were significantly increased in the V-EX group. Conversely, we found that F-EX rats showed no significant 5-HT changes and increased anxiety-like behavior. VL-EX did not have significant beneficial effects on any of the experimental parameters. These data suggest that only unlimited voluntary exercise stimulates the serotonergic system and suppresses anxiety-like behavior.

体育锻炼对身心健康都有益，尽管尚不清楚自愿和强迫锻炼是否具有相同的效果。我们调查了慢性强迫和自愿轮转对大脑中血清素（5-HT），其代谢物5-羟基吲哚乙酸（5-HIAA）和焦虑样行为改变的影响。将48只大鼠随机分配至标准笼子（sentent control：SC）；自愿运动（可在车轮上自由行驶，V-EX）；自愿的有限运动（每天只能使用1小时的车轮，VL-EX）；和强迫运动（在电动轮上运行，F-EX）。4周后，对大鼠进行了野外试验（OFT），或在主要的血清素能神经细胞体和投射区域测量了其5-HT和5-HIAA的水平。与SC组相比，V-EX组背侧和正中缝核的5-HT和5-HIAA水平升高，而VL-EX组和F-EX组则没有升高。在室下丘脑旁核和尾状壳核中，V-EX组仅5-HT水平升高。有趣的是，在杏仁核中，V-EX组仅5-HIAA水平显着升高。相反，我们发现F-EX大鼠没有明显的5-HT改变，并没有增加焦虑样行为。VL-EX对任何实验参数均没有明显的有益影响。这些数据表明，只有无限量的自愿运动才能刺激血清素能系统并抑制焦虑样行为。V-EX组仅5-HT水平升高。有趣的是，在杏仁核中，V-EX组仅5-HIAA水平显着升高。相反，我们发现F-EX大鼠没有明显的5-HT改变，并没有增加焦虑样行为。VL-EX对任何实验参数均没有明显的有益影响。这些数据表明，只有无限量的自愿运动才能刺激血清素能系统并抑制焦虑样行为。V-EX组仅5-HT水平升高。有趣的是，在杏仁核中，V-EX组仅5-HIAA水平显着升高。相反，我们发现F-EX大鼠没有明显的5-HT改变，并没有增加焦虑样行为。VL-EX对任何实验参数均没有明显的有益影响。这些数据表明，只有无限量的自愿运动才能刺激血清素能系统并抑制焦虑样行为。