Identifying candidate genes involved with reduced masticatory sensory input in senescence accelerated mouse prone 8 hippocampus

许多检验减少咀嚼输入对大脑功能影响的实验程序经常使用粉状食物，将其与通常用于喂养的固体食物一起碾碎。在这项研究中，我们最初开发了流质饮食食品，通过它的卡路里和成分类似于2006年常用的固体食物来改变更不同的咀嚼情况。然后，2007年，将这种流食食物喂给衰老加速的小鼠俯卧8号。然而，原因并不确定，许多实验动物已经死亡，实验程序的完成变得困难。然后，我们参考Kim的报告(J.NeuroScience 2005；25(6)：1532-9)，使用基因芯片系统检测了当实验动物暴露于急性束缚应激并在同一任务中表现出咬人行为时，大鼠海马区的基因表达。结果，我们能够挑选出大约30个基因，比如热休克蛋白，Toll样受体3，这些基因的外观发生了两次或更多的变化。同时，我们还提取了大约70个基因作为一个基因，这些基因的容纳量是它的一半或更少。在Morris水迷宫分析中，咬伤组小鼠的空间记忆和学习能力比单纯应激组恢复得更好。此外，在免疫组织化学研究中，咬合组大鼠海马区CA1、CA3和DG区神经元活性标志物Fos蛋白的表达较单纯应激组明显减少，提示严重急性应激时咬合活动对大鼠海马区功能损害具有一定的抑制作用。

Many of experimental procedures for examining the influence of reduced masticatory input on the brain function often use powdery food that crushes it with the solid food usually used to feed. In this research, we have originally developed liquid diet foods for changing the more differential masticatory situation through it was a calories and compositions similar to the usual used solid food in 2006. And then, the liquid diet food was fed to the senescence accelerated mouse prone 8 in 2007. However, the reason was uncertain that a lot of experimental animals had died; the accomplishment of the experimental procedure became difficult. Then, we have examined the gene expression by using microarry system in rat hippocampus when the experimental animals expose to acute restraint stress and displayed biting behavior during the same task referring to the Kim's report (J.Neuroscience 2005; 25(6):1532-9.). As a result, we were able to pick up about 30 genes, such as heat shock protein, toll-like receptor 3, that showed the appearance twice or more changed. Simultaneously, we have also picked up about 70 genes as a gene that admitted 1/2 times or less than it. In Morris water maze analysis, spatial memory and learning activity of biting group of ddy mice were indicated more recovery the ability compared with the stress only group. Moreover, the expression of Fos protein, which generally used as a maker for neuronal activity, have decreased on CA1, CA3 and DG of rat hippocampus in biting group compared with stress only group in the immunohistochemistry study.These findings possibility suggested that biting activity during the severe acute stress was attenuated impaired hippocampus function.