earticle

영어

The purpose of this study was to investigate the effects of regular treadmill exericse after social isolation on brain-derived neurotrophic factor(BDNF), nerve growth factor(NGF) and 5-bromo-2'- deoxyuridine- 5'-mono-phosphate(BrdU) -positive cell in the hippocampus, and serotonin-, TPH-positive cells in the raphe nuclei, and depression behaviors in the adult rats. Forty male Sprague-Dawley rats (31 weeks) were divided into four groups: (1) group housing and control group (GCG, n = 10); (2) group housing and exercise group (GEG, n = 10); (3) isolated housing and control group (ICG, n = 10); and (4) isolated housing and exercise group (IEG, n = 10). After 2 week of housing under the normal condition of 3 animals per cage, rats were socially isolated via transfer to individual cages for 8 weeks. Rats were then subjected to treadmill exercise for 5 days per week for 8 weeks, during which time the speed of the treadmill was gradually increased. The blood corticosterone level in the ICG was intend to increase, whereas in the IEG was intend to decrease compared to the ICG. Compared to the GCG, levels of BDNF and NGF were significantly decreased in the ICG, and significantly increased in the IEG (p < .001 respectively). There were significantly more BrdU-positive cells in the IEG compared to the GCG and ICG(p < .001). Serotonin-, TPH-positive cells in the GEG and IEG were significantly increased compared to the GCG and ICG(p < .01, p < .001). In the forced swim test, immobility time was significantly increased in the ICG, and significantly decreased in the IEG compared to the ICG(p < .001). These results show that regular treadmill exercise after social isolation not only increases the levels of BDNF and NGF to induce survival of cells in the hippocampus, but also improves depression-like behavior by increasing the number of serotonin, TPH cells expression in the raphe nuclei.