Exercise Promotes Neural Cell Growth During Middle-Age
Study finds regular exercise increases levels of neuronal growth factor, thereby promoting new neuron growth in middle-aged mice
MONDAY, Nov. 24 (HealthDay News) -- Exercise increases production of a neural growth factor and its receptor, promoting proliferation and survival of neural stem/precursor cells in mice, researchers report in the November issue of the Journal of Applied Physiology.
Chih-Wei Wu, from the National Cheng Kung University Medical College in Tainan, Taiwan, and colleagues trained mice of different ages to perform treadmill exercise. The investigators measured production of the growth factor brain-derived neurotrophic factor (BDNF) and its receptor (TrkB), along with the number of neural stem/precursor cells following five weeks of exercise.
Compared with younger (3-month-old) mice, middle-aged (13-month-old) mice exhibited dramatically decreased neurogenesis, reducing to approximately 5 percent of the neurogenesis observed in the younger mice, the report indicates. However, neurogenesis was significantly increased (by approximately 200 percent) in middle-aged mice that exercised compared with mice that did not exercise. Treadmill exercise also resulted in enhanced neurite outgrowth and improved survival of neural stem/precursor cells, the investigators found. Levels of BDNF and TrkB, which declined with age, were also enhanced following treadmill exercise.
Because BDNF signaling is known to promote neuronal growth and survival, the authors suggest that increased BDNF levels lead to enhanced neurogenesis during middle age. "Taken together, mandatory running exercise alters the brain chemistries of middle-aged animals toward an environment that is favorable to neural stem/precursor cell proliferation, survival, and maturation," the authors write.