Mei Hao, Logothetis Nikos K, Eschenko Oxana
Max Planck Institute for Biological Cybernetics, Tübingen 72076, Germany.
Centre for Imaging Sciences, Biomedical Imaging Institute, The University of Manchester, Manchester M13 9PT, United Kingdom.
Learn Mem. 2018 Feb 15;25(3):129-137. doi: 10.1101/lm.047134.117. Print 2018 Mar.
Spatial navigation depends on the hippocampal function, but also requires bidirectional interactions between the hippocampus (HPC) and the prefrontal cortex (PFC). The cross-regional communication is typically regulated by critical nodes of a distributed brain network. The thalamic nucleus reuniens (RE) is reciprocally connected to both HPC and PFC and may coordinate the information flow within the HPC-PFC pathway. Here we examined if RE activity contributes to the spatial memory consolidation. Rats were trained to find reward following a complex trajectory on a crossword-like maze. Immediately after each of the five daily learning sessions the RE was reversibly inactivated by local injection of muscimol. The post-training RE inactivation affected neither the spatial task acquisition nor the memory retention, which was tested after a 20-d "forgetting" period. In contrast, the RE inactivation in well-trained rats prior to the maze exposure impaired the task performance without affecting locomotion or appetitive motivation. Our results support the role of the RE in memory retrieval and/or "online" processing of spatial information, but do not provide evidence for its engagement in "off-line" processing, at least within a time window immediately following learning experience.
空间导航依赖于海马体功能，但也需要海马体（HPC）与前额叶皮质（PFC）之间的双向交互作用。这种跨区域通信通常由分布式脑网络的关键节点进行调节。丘脑 reuniens 核（RE）与 HPC 和 PFC 均存在相互连接，可能会协调 HPC - PFC 通路内的信息流。在此，我们研究了 RE 活动是否有助于空间记忆巩固。训练大鼠在类似纵横字谜的迷宫中沿着复杂轨迹寻找奖励。在每日五次学习训练中的每次训练结束后，立即通过局部注射蝇蕈醇使 RE 可逆性失活。训练后 RE 失活既不影响空间任务的获取，也不影响记忆保持，记忆保持在 20 天“遗忘”期后进行测试。相比之下，在训练有素的大鼠于迷宫暴露前使 RE 失活会损害任务表现，但不影响运动或食欲动机。我们的结果支持 RE 在记忆检索和/或空间信息“在线”处理中的作用，但至少在紧接学习经历后的时间窗口内，未提供其参与“离线”处理的证据。
