Memory declines with age This phenomenon is associated with hippocampal degeneration such as shrinkage in neuron size regressions of dendrites and dendritic spines and alteration in synaptic proteins Running exercise is known to promote neurogenesis and enhance the performance of learning and memory However whether running exercise is capable of improving learning and memory in aged animals remains unclear In this study we compared the memory performance and neuronal plasticity of young (2~3 months) middle-aged (9~12 months) and aged (>18 months) mice with or without six weeks of moderate intensity treadmill running training Neuronal plasticity was determined by the morphology long-term potentiation (LTP) and synaptic proteins of the pyramidal neurons of the hippocampal CA1 region The results revealed that middle-aged and aged mice had worse hippocampus-dependent non-spatial memory than that of young mice The lengths and branch numbers of total dendrites and diameter and spine density of apical dendrite were reduced in the middle-aged and aged mice A marginal decline (p = 0 058) of the LTP in old mice was evident The levels of synaptic proteins (i e snap25 syt1 NR1 PSD95 BDNF/TrkB) were similar among three groups Six weeks of running exercise significantly enhanced the age-reduced memory performance Running exercise increased the length and branch numbers of total dendrites and diameter and spine density of apical dendrite in middle-aged and aged mice Furthermore the levels of LTP and BDNF were increased by running exercise in both young and aged mice However the levels of snap25 syt1 NR1 PSD95 and TrkB were unaltered by running exercise In conclusion moderate intensity running exercise effectively improves the aging-associated memory impairment The beneficial effects of running exercise are probably caused by enhancing BDNF signaling which then increases hippocampal neuroplasticity
Effects of treadmill exercise on hippocampal neuroplasticity during aging in mice
乃文, 古. (Author). 2014 9月 5
學生論文: Master's Thesis