Change of Brain Blood Flow during Masticatory Movement and Bodily Movement

本实验的目的是利用近红外光谱（NIRS）技术来阐明咀嚼运动和其他身体运动对脑血流的影响。首先，开发了能够视觉和定量地评估与咀嚼运动和其他身体运动相关的脑血流变化的脑血流分析系统。第二，要求健康受试者进行咀嚼运动、手指敲击运动和手的开合运动，每次30秒。所有运动的脑血流量增加，增加量是最大的咀嚼运动，其次是手指敲击运动和手的开合运动。第三，要求健康受试者分别在其习惯性和非习惯性咀嚼侧咀嚼口香糖2分钟。习惯性咀嚼侧的血流变化量显著大于非习惯性咀嚼侧。第四，受试者被要求咀嚼四种类型的软糖（5%，6.5%，8%和9.5%明胶的顺序）和三种类型的软糖（甜，普通，苦）在他们的习惯咀嚼侧20秒。脑血流量以5%明胶胶冻组最低，6.5%、8%、9.5%明胶胶冻组脑血流量显著增加。脑血流量以普通软糖最高，而甜、苦软糖则显著降低。从这些结果可以看出，咀嚼激活大脑活动，习惯性咀嚼侧比非习惯性咀嚼侧具有更强的影响，并且食物的硬度和味道影响脑血流量的增加和减少。

The purpose of this experiment was to clarify the effect of masticatory movement and other bodily movements on the brain blood flow using NIRS (near infrared spectroscopy). First, the brain blood flow analyzing system able to evaluate both visually and quantitatively the changes in the brain blood flow related to masticatory movement and other bodily movements was developed. Second, healthy subjects were asked to perform masticatory movement, finger tapping movement and opening and closing of the hand movement for 30 seconds each. The brain blood flow increased for all movements and the amount of increase was the greatest for the masticatory movement, followed by the finger tapping movement and by the opening and closing of the hand movement. Third, health subjects were asked to chew chewing gum on their habitual and non-habitual chewing sides for 2 minute respectively. The amount of change in blood flow was significantly larger for the habitual chewing side than for the non-habitual chewing side. Fourth, the subjects were asked to chew the four types of gumi-jelly (5%, the order of 6.5%, 8%, and 9.5% gelatin) and the three types of gumi-jelly (sweet, common, bitter) on their habitual chewing side for 20 seconds. The amount of brain blood flow were the lowest for the 5% gelatin gumi-jelly and significantly increased in the order of 6.5%, 8%, and 9.5%. The amounts of brain blood flow were the highest for the common gumi-jelly and significantly decreased in the sweet and bitter gumi-jelly. From these results it was suggested that mastication activated brain activities and that the habitual chewing side had a stronger effect than the non-habitual chewing side and that hardness and taste of the food affected the increase and decrease in the amount of brain blood flow.