学习记忆是大脑最重要的功能之一。近年来，昼夜节律紊乱对学习记忆的影响更是成为国内外的研究热点。然而，由于大部分研究是在昼行性果蝇和夜行性啮齿类中开展的，导致“参与调控记忆巩固的过程是否实际上依赖于内在昼夜节律性，还是同时受到光照影响”这一科学问题在国内外研究中还未见明确结论。根据前期结果提示，记忆巩固相关分子Rac1具有内在昼夜节律性。由此我们提出 “内在昼夜节律可能通过Rac1-PAK1通路影响记忆巩固”这一科学假设。本项目拟利用昼行性的非人灵长类模式动物树鼩，建立触摸屏认知任务模型，通过与大鼠比较不同光照条件下的脑高级认知能力，并结合神经成像技术、细胞和分子生物学手段，阐明究竟是内在昼夜节律还是光/暗周期在记忆巩固中起主导作用，探索Rac1-PAK1通路的作用机制。预期研究成果可为揭示昼夜节律紊乱导致的记忆相关脑疾病机理研究提供新证据，也为该研究领域提供一种全新的、更加优化的动物模型。

Learning and memory is one of the most important functions of the brain. In recent years, the influence of circadian rhythms on learning and memory has become a hot topic. However, it is not clear that whether the process of memory conclusion is dependent on the intrinsic circadian rhythm or the light. One of the most important reasons may that most of the studies are carried out in diurnal drosophila and nocturnal rodents. According to our previous results, the memory consolidation related molecule Rac1 has an intrinsic circadian rhythm. Thus we propose that the "internal circadian rhythm may affect memory consolidation through the Rac1-PAK1 pathway". We intend to use the diurnal non-human primate tree shrew animal model, by establishing a touch screen cognitive task model, compared the cognitive ability between tree shrews and rats under different light conditions, to clarify whether the intrinsic circadian rhythm or light/dark cycle play a leading role in memory consolidation. The neural imaging technology, cell and molecular biology methods are also used to explore the mechanism of Rac1-PAK1 pathway in memory consolidation under different circadian rhythm mode. The research results can provide new evidences for revealing the mechanism of memory related brain diseases induced by circadian rhythm disorders, and provide a new and more optimized animal model for this field.