Effects of exercise on hippocampal synaptic plasticity in mice of different ages

• Main Authors: Hsiao-ChiLai, 賴筱琦
• Other Authors: Yu-Min Kuo
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/31295780051608365351

碩士 === 國立成功大學 === 細胞生物及解剖學研究所 === 98 === Aging implies a primary risk factor for disease of the central nervous system most especially neurodegenerative disorders. In aged humans the cortex and hippocampus atrophy and learning and reference memory declines. Similarly, the ability to learn new tasks decreases with age in rodents. The number of synaptic contacts, synaptic strength and plasticity are also reduced in the cortex and hippocampus of aged rodents. Although the aging-induced cognitive decline remains unclear, physical exercise has been shown to improve spatial learning and memory in humans and animals. Our results showed that six weeks of TR could improve spatial learning in middle and aged mice, but not in young mice. Moreover, TR also significantly enhanced memory performance in middle-aged mice, while the young and aged mice were unaffected by TR. At middle-aged mice, TR not only enhanced the dendritic branches and arbors but also increased the dendritic length and spine density of hippocampal CA3 pyramidal neurons. Furthermore, six weeks of TR induced the level of presynaptic proteins SNAP25 and SYT1 expression. These results suggest that enhancing learning and memory performance in middle-aged animals may be via the increases of synaptic vesicle in the hippocampus CA3 neurons.