偏侧咀嚼对记忆相关脑功能区影响的研究

Chewing-side preference (CSP) is a commonly harmful oral habits, which will lead to serious diseases of stomatognathic system, even headache, neck, shoulder and back pain. However, there was little research about the effects of CSP on central nervous system, especially on the learning and memory function. Previous studies of our team have found that parahippocampal gyrus was activated in the patients with CSP during clenching. Moreover, the hippocampus and learning and memory are closely related. Therefore, we attempts to study 2 aspects on the basis of our previous results: 1. Through the establishment of rats model of CSP, the effects and mechnism of CSP on cerebral functional district were explored by methods of immunohistochemistry, molecular biology, water maze experiment and high performance liquid chromatography, et al. 2. Using functional magnetic resonance imaging and magnetic resonance spectroscopy, detect the activation characteristics of cerebral cortex and central neurotransmitters in patients with CSP. The research will play an important role in promoting the study of the function of chewing and cognitive function.

偏侧咀嚼是比较常见的口腔不良习惯，可以导致开口受限、颞下颌关节区疼痛、颈肩部疼痛、头痛、头部麻木等症状，严重影响人们的生活质量。目前，偏侧咀嚼对中枢神经系统影响的研究甚少，国内外尚未见其对学习记忆功能影响的相关报道。本课题组在前期研究发现偏侧咀嚼患者紧咬牙运动影响海马旁回激活的现象，而海马与学习记忆活动密切相关。本研究在此基础上，通过建立偏侧咀嚼大鼠模型，采用组织病理学、神经生理学、免疫组织化学和水迷宫行为学等实验方法探讨偏侧咀嚼对记忆相关脑功能区的影响；并采用先进的功能性磁共振成像和磁共振波谱等脑功能成像手段研究牙列完整和单侧后牙缺失的偏侧咀嚼患者记忆相关大脑皮层的激活特点和代谢物质改变的生理特点。该课题的研究对咀嚼功能与认知功能的研究将起到进一步的推动作用。

偏侧咀嚼对脑功能乃至全身健康产生重要影响。课题组前期发现运动相关的皮层下中枢参与了偏侧咀嚼患者双侧咀嚼运动的调控，而且发现初级感觉运动皮层对偏侧咀嚼患者咀嚼运动的调控具有对侧半球优势。偏侧咀嚼时的感觉反馈可以刺激大脑，而海马是这种作用的关键靶点。偏侧咀嚼中枢调控的分子机制还不清楚。本研究通过建立偏侧咀嚼大鼠模型，采用组织病理学、神经生理学、免疫组织化学和水迷宫行为学等实验方法探讨偏侧咀嚼对记忆相关脑功能区的影响；1.采用HPLC法观察偏侧咀嚼小鼠海马中5-HT的水平、western blot法检测海马区5-HT受体5-HT1A蛋白水平、PCR法观察海马区5-HT1A、BDNF的mRNA水平。结果显示，偏侧咀嚼小鼠海马中5-HT1A受体的基因和蛋白水平及BDNF的mRNA水平也显著低于正常对照组。2. 采用Morris水迷宫观察偏侧咀嚼对小鼠学习记忆能力的影响，右侧咀嚼障碍小鼠的游泳潜伏期较正常小鼠明显增加，第三象限路程百分比明显减少。这些结果提供了初步的证据，提示5-HT1A受体在偏侧咀嚼中枢调控机制中发挥重要作用。但偏侧咀嚼中枢调控的分子机制有待进一步研究。