Forced running enhances neurogenesis in the hippocampal dentate gyrus of adult rats and improves spatial learning ability

Abstract

To investigate the effect of forced running on neurogenesis in the hippocampal dentate gyrus ( DG ) of adult rats, 5-bromo-2-deoxyuridine ( BrdU ), the thymidine analog, that can be incorporated into the DNA during the S phase of cell cycle, was applied to mark cell proliferation. Neuroepthelial stem cell protein (nestin) expression was used to identify neural stem cell/precursor cells. The BrdU- and nestin-positive cells were examined by immunocytochemical technique. The ability of spatial learning and memory was evaluated by Y maze and Morris water maze tests to explore the functional role of the newly born cells in DG after running. It was found that the number of BrdU- and nestin-positive cells in the dentate gyrus in running groups was significantly increased as compared to that of control group. The effect of forced running on neurogenesis was intensity-dependent. In addition, an improvement of spatial learning ability was observed after forced running in Y maze, as well as in Morris water maze tests. These findings demonstrated that forced running could enhance neurogenesis in the hippocampal dentate gyrus of adult rats and facilitate acquisition of a hippocampus-related spatial learning task. [J Physiol Sci. 2006;56 Suppl:S193]