Influence of Exercise on Stress and Depression

LANGUAGE NOTE | Document text in English; abstract also in Chinese. There is evidence in human subjects that aerobic physical exercise boosts the immune system, influences stress hormone levels and depressive feelings (Brenner, Shek, Zamecnik, & Shephard, 1998). Moderate physical exercise can prevent detrimental effects of stress and depression as a result of the interaction between the neuroendocrine system and the immune system post aerobic exercise (Fleshner, 2000). In this study, the contribution of intensity and duration of exercise to modulation of stress responses were assessed. Physical exercise modulation of the response to a stressful threatening event was examined in rats at the behavioral and biochemical levels. At the behavioral level, the following parameters were measured: anxiety (Elevated Plus Maze, Startle reflex response measures), depression (Learned helplessness) exploratory orientation (Open field) and of cognitive abilities (Spatial learning and memory, active avoidance). At the biochemical level, alterations in the basal concentrations of neurosteroids and in responsiveness to stress were measured. In response to acute stress there is a rapid increase in neurosteroids (Vllee, Rivera, Koob, Purdy, & Fitzgerald, 2000). The neurosteroid allopregnanolone has been shown to be a potent ligand of gamma-aminobutyric acid (GABA)-A receptors. It enhances its receptor-mediated inhibitory effects in the rat (Guo et al., 1995; Pericic, Svob, Jazvinscak, & Mirkovic, 2000). The neurosteroid 3 alpha, 5 alpha THP acts like an antidepressant drug. It interacts with the central delta receptor, which has antidepressant-like effects (Khisti, Chopde, & Jain, 2000; Reddy, Kaur, & Kulkani, 1998). 進行適量運動能夠產生正面的健康影響運動與身體免疫系統、壓力賀爾蒙和憂鬱情況的相關研究經已得到確定。本文嘗試以不同的運動強度及時期並用白鼠作用受試對象去探討運動與壓力兩者的生理變化。