School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin 300070, China.
School of Basic Medicine, Tianjin Medical University, Tianjin 300070, China.
Brain Res Bull. 2024 Feb;207:110887. doi: 10.1016/j.brainresbull.2024.110887. Epub 2024 Jan 26.
Working memory refers to a system that provides temporary storage and manipulation of the information necessary for complex cognitive tasks. The prefrontal cortex (PFC) and hippocampus (HPC) are major structures contributing to working memory. Accumulating evidence suggests that the HPC-PFC interactions are critical for the successful execution of working memory tasks. Nevertheless, the directional information transmission within the HPC-PFC pathway remains unclear. Using simultaneous multi-electrode recordings, we recorded local field potentials (LFPs) from the medial prefrontal cortex (mPFC) and ventral hippocampus (vHPC) while the rats performed a spatial working memory task in a Y-maze. The directionality of functional interactions between mPFC and vHPC was assessed using the phase-slope index (PSI). Our findings revealed a frequency-specific oscillatory synchrony in the two regions during the spatial working memory task. Furthermore, an increased high-gamma flow from vHPC to mPFC manifested exclusively during correctly performed trials, not observed during incorrect ones. This suggests that the enhanced high-gamma flow reflects behavioral performance in working memory. Consequently, our results indicate an major role of directional frequency-specific communication in the hippocampal-frontal circuit during spatial working memory, providing a potential mechanism for working memory.
工作记忆是指为完成复杂认知任务提供临时存储和信息操作的系统。前额叶皮层（PFC）和海马体（HPC）是对工作记忆有重要贡献的主要结构。越来越多的证据表明，HPC-PFC 相互作用对于成功执行工作记忆任务至关重要。然而，HPC-PFC 通路内的定向信息传递仍然不清楚。使用同步多电极记录，我们在大鼠在 Y 迷宫中执行空间工作记忆任务时，从内侧前额叶皮层（mPFC）和腹侧海马体（vHPC）记录局部场电位（LFPs）。使用相位斜率指数（PSI）评估 mPFC 和 vHPC 之间功能相互作用的方向。我们的发现揭示了在空间工作记忆任务期间两个区域中特定频率的振荡同步。此外，仅在正确执行的试验中表现出从 vHPC 到 mPFC 的增强的高伽马流量，而在不正确的试验中则没有观察到。这表明增强的高伽马流量反映了工作记忆中的行为表现。因此，我们的结果表明，在空间工作记忆期间，海马-前额叶回路中的定向频率特异性通信起着重要作用，为工作记忆提供了一种潜在的机制。
