Functional connectivity in central nucleus of amygdala, paraventricular hypothalamus, and nucleus tractus solitarii circuits during high-intensity endurance treadmill exercise in rats

High-intensity endurance exercise (HIE) induces negative emotions alongside fatigue, suffering, and changes in cardiovascular responses, these regulations could be important for athletic performance. Previous studies have reported that limbic brain stem regions, including the central nucleus of amygdala (CeA), paraventricular hypothalamus (PVH), tractus solitarii (NTS), play roles emotional response autonomic regulation. However, how regions interact during HIE remains unclear. In this study, Wistar rats were subjected to 90-min treadmill running sessions at different intensities (sedentary, low-intensity, high-intensity: 0, 20, 34 m/min, respectively; n = 9 per group). After exercise, tissues extracted examined c-Fos immediate early gene expression such as CeA, PVH, NTS each intensity. The c-Fos-positive cells counted, then a partial correlation analysis was performed examine functional connectivity exercise. As result, numbers increased an intensity-dependent manner. Furthermore, analyses between CeA (CeA-NTS), PVH (PVH-NTS), (CeA-PVH) exhibited significant coefficients but not sedentary low-intensity exercises. Thus, results suggest CeA-PVH, PVH-NTS, CeA-NTS may enhanced HIE. This also involved regulation