Chewing effects on intelligent activities in the elderly

包括预防老年痴呆症在内的老年人保健是日本老龄化社会面临的关键问题之一。目前，人们的注意力主要集中在咀嚼对老年人大脑高级功能（如认知）的影响上。在这项研究中，我们使用功能性磁共振成像（fMRI）来评估年龄对年轻成年人与咀嚼相关的大脑区域活动的影响（19-26岁），中年（42-55岁），（65-73岁）健康人。在有节奏地咀嚼口香糖和休息的周期中使用fMRI我们发现，在所有受试者中，咀嚼导致感觉运动皮层、小脑、丘脑、辅助运动区和小脑皮层的BOLD信号双侧增加，右侧前额叶区单侧增加。在前三个区域中，信号增加以年龄依赖的方式衰减，而在右前额叶区，则匡威。其余两个地区没有显示出显着差异， ...更多信息 年代。这些结果表明，咀嚼可以刺激大脑皮层中与记忆相关的功能区域，而且，在记忆测试中，咀嚼引起海马（记忆形成不可缺少的脑区）在图片编码过程中BOLD信号的显著增加，与不咀嚼的人相比，这意味着咀嚼参与了海马网络系统。此外，长期戴用不当的老年人戴用新的全口义齿两周后，在图片编码时，海马BOLD信号值明显增高，而咀嚼时海马BOLD信号值明显高于不咀嚼时，暗示咀嚼参与海马网络系统。另外，未戴全口义齿的老年人戴全口义齿2周后，海马BOLD信号在图片编码时出现高值，记忆测验成绩也较高，提示咀嚼功能在老年人学习记忆的维持和/或恢复中起着重要作用。少

Health care of the elderly including prevention of senile dementia is one of the key issues facing Japanese aged society. Much attention is currently focused on chewing effects in the elderly on higher brain function such as cognition. In this study, we used functional magnetic resonance imaging (fMRI) to assess the effect of aging on brain regional activity associated with chewing in young adult (19-26 yrs), middle-aged (42-55 yrs), and aged (65-73 yrs) healthy humans.Using fMRI during cycles of rhythmic gum-chewing and rest (no chewing), we found that, in all subjects, chewing resulted in a bilateral increase in the BOLD signals in the sensorimotor cortex, cerebellum, thalamus, supplementary motor area, and insula, and a unilateral increase in the right prefrontal area. In the first three regions, the signal increases were attenuated in an age-dependent manner, whereas, in the right prefrontal area, the converse was seen. The remaining two regions showed no significant differences wi … More th ages. These findings suggest that chewing may stimulate functionally memory-related regions in the cerebral cortex.Furthermore, chewing caused a significantly higher increase of the BOLD signals in the hippocampus, an indispensable brain region for memory formation, during picture encoding in the memory test, in comparison with those without chewing, implying involvement of chewing in the hippocampal network system. Furthermore, two weeks after wearing the new full proper dentures of the aged subjects whose denture was improper for long time, higher value of the hippocampal BOLD signals were caused during picture encoding.In addition, during picture encoding, chewing caused a significantly higher increase of the BOLD signals in the hippocampus, being believed to play an indispensable brain region for memory formation, in comparison with those without chewing, implying involvement of chewing in the hippocampal network system. Furthermore, two weeks after wearing the full dentures of the aged subjects who had never worn them, higher value of the hippocampal BOLD signals were caused during picture encoding, and the subject got higher scores in the memory test.These results indicate that masticatory function plays a crucial role in maintaining and/or recovering learning and memory in the elderly. Less