Effects of exercise on neurogenesis in the dentate gyrus and ability of learning and memory after hippocampus lesion in adult rats

Abstract

Present experiments were undertaken to explore the effects of exercise on dentate gyrus (DG) neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Hippocampus lesion was produced by intrahippocampal microinjection of kainic acid (KA). Bromodeoxyuridine (BrdU) was used to label dividing cells. Y maze test was used to evaluate the ability to learning and memory. Exercise was conducted in the form of forced running in a motor-driven running wheel. The speed of wheel revolution was regulated at 3 kinds of intensity: lightly running, moderately running, or heavily running. Hippocampus lesion could increase the number of BrdU-labeled DG cells, moderately running after lesion could further enhance the number of BrdU-labeled cells and decrease the error number (EN) in Y maze test, while neither lightly running, nor heavily running had such effects. There was a negative correlation between the number of DG BrdU-labeled cells and the EN in the Y maze test after running. The results suggested that moderate exercise could enhance the DG neurogenesis and ameliorate the ability to learning and memory in hippocampus-lesioned rats. [J Physiol Sci. 2006;56 Suppl:S193]