Is the loss of the tooth a risk factor of the Alzheimer's disease? Examination by microdialysis methods

目的：为了阐明磨牙缺失对学习和记忆的影响，海马谷氨酸释放过程中的被动回避task.Methods遥测谷氨酸生物传感器测量：雄性Sprague-Dawley大鼠。在全麻下，EXT组（n=8）拔除所有上颌磨牙; CON组（n=8）麻醉后不拔牙。在7周龄时，大鼠进行被动回避任务，包括获取和保留试验。同时测定海马谷氨酸释放。首先，在获取试验期间，将大鼠置于亮室中，并测量它们进入暗室之前的持续时间（反应潜伏期）。在大鼠进入暗室后，立即通过网格地板施加电击。24小时后，进行保持试验，并以相同的方式测量反应潜伏期。此外，生物传感器被用来测量海马谷氨酸的释放之前和之后开始的每一个trial.Results：关于反应潜伏期在被动回避任务，没有显着差异被视为组之间的收购试验。在保留试验中，两组的反应潜伏期均增加，但EXT组明显缩短。此外，海马谷氨酸释放在收购试验显着较短的EXT组，但在保留试验中，谷氨酸释放没有显着差异被视为groups.Conclusion：磨牙缺失可能会阻碍学习和记忆。

Purpose : To clarify the effects of molar tooth loss on learning and memory, hippocampal glutamate release during a passive-avoidance task was measured with a telemetric glutamate biosensor.Methods: Male Sprague-Dawley rats were used. Under general anesthesia, all the maxillary molars were extracted from the EXT group rats (n=8); those in the CON group (control, n=8) were anesthetized without tooth extraction. At age 7 weeks, the rats were subjected to a passive-avoidance task consisting of acquisition and retention trials. Simultaneously, hippocampal glutamate release was measured. First, during the acquisition trial, the rats were placed in a light compartment, and the duration before they entered a dark compartment was measured (reaction latency). Immediately after the rat entered the dark compartment, an electric shock was applied through a grid floor. After 24h, the retention trial was performed, and the reaction latency was measured in the same manner. Further, a biosensor was used to measure the release of hippocampal glutamate before and after the start of each trial.Results: Regarding the reaction latency during the passive-avoidance task, no significant differences were seen between the groups in the acquisition trial. Reaction latency increased in both groups in the retention trial, but was significantly shorter in the EXT group. Furthermore, hippocampal glutamate release in the acquisition trial was significantly shorter in the EXT group, but in the retention trial, no significant difference in glutamate release was seen between the groups.Conclusion: Molar tooth loss may impede learning and memory.