Purpose:Traumatic brain injury (TBI) causes cognitive impairments, motor deficits, and neuropsychiatric/behavioral deficits problems. Transplantation of bone marrow stromal cells (BMSCs) facilitates functional recovery from brain insults. Treadmill exercise increases neurogenesis and inhibits apoptosis. In this study, we investigated the effects of BMSC transplantation in combination with treadmill exercise on memory function, by evaluating its effect on neurogenesis and apoptosis in the hippocampus following TBI.Methods:TBI was induced using an electromagnetic-controlled cortical impact device. BMSCs were transplanted into both sides of traumatic scar region 1 week after TBI induction. One week after transplantation of BMSCs, the rats in the exercise groups were trained to run on a treadmill for 30 minutes once daily for 28 days. Step-down avoidance task and radial 8-arm maze test were conducted. Levels of 5-bromo-2ʹ-deoxyuridine and caspase-3 were evaluated using immunohistochemistry. Western blot was used to evaluate the expression of brain-derived neurotrophic factor (BDNF), tyrosine kinase B (TrkB), total-extracellular signal-regulated kinase 1 and 2 (t-ERK1/2), phosphorylated-ERK1/2 (p-ERK1/2), Bcl-2, and Bax.Results:TBI deteriorated memory function, suppressed neurogenesis, and accelerated apoptosis in the hippocampus. Treadmill exercise and BMSC transplantation independently improved memory function by increasing neurogenesis with suppression of apoptosis through the BDNF-ERK pathway in the TBI-induced rats. Combination of BMSC transplantation with treadmill exercise showed additional enhancement of neurogenesis and suppression of apoptosis in the hippocampus.Conclusions:The present study shows that treadmill exercise may aid the therapeutic effect of BMSC transplantation on TBI in rats.

Purpose:Stress during pregnancy is a risk factor for the development of anxiety-related disorders in offspring later in life. The effects of treadmill exercise on anxiety-like behaviors and hippocampal cell proliferation were investigated using rats exposed to prenatal stress.Methods:Exposure of pregnant rats to a hunting dog in an enclosed room was used to induce stress. Anxiety-like behaviors of offspring were evaluated using the elevated plus maze test. Immunohistochemistry for the detection of 5-bromo-2ʹ- deoxyuridine and doublecortin (DCX) in the hippocampal dentate gyrus and 5-hydroxytryptamine 1A receptors (5-HT1A) in the dorsal raphe was conducted. Brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) levels in the hippocampus were evaluated by western blot analysis.Results:Offspring of maternal rats exposed to stress during pregnancy showed anxiety-like behaviors. Offspring also showed reduced expression of BDNF, TrkB, and DCX in the dentate gyrus, decreased cell proliferation in the hippocampus, and reduced 5-HT1A expression in the dorsal raphe. Postnatal treadmill exercise by offspring, but not maternal exercise during pregnancy, enhanced cell proliferation and expression of these proteins.Conclusions:Postnatal treadmill exercise ameliorated anxiety-like behaviors in offspring of stressed pregnant rats, and the alleviating effect of exercise on these behaviors is hypothesized to result from enhancement of cell proliferation through 5-HT1A activation in offspring rats.