Department of Cognitive Neuroscience, Faculty of Education and Psychology, University of Tabriz, Tabriz, Iran.
Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Brain Stimul. 2024 Sep-Oct;17(5):1101-1118. doi: 10.1016/j.brs.2024.09.005. Epub 2024 Sep 12.
Navigational decision-making tasks, such as spatial working memory (SWM), rely highly on information integration from several cortical and sub-cortical regions. Performance in SWM tasks is associated with theta rhythm, including low-frequency oscillations related to movement and memory. The interaction of the ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC), reflected in theta synchrony, is essential in various steps of information processing during SWM. We used a closed-loop neurofeedback (CLNF) system to upregulate theta power in the mPFC and investigate its effects on circuit dynamics and behavior in animal models. Specifically, we hypothesized that enhancing the power of the theta rhythm in the mPFC might improve SWM performance. Animals were divided into three groups: closed-loop (CL), random-loop (RL), and OFF (without stimulation). We recorded local field potential (LFP) in the mPFC while electrical reward stimulation contingent on cortical theta activity was delivered to the lateral hypothalamus (LH), which is considered one of the central reward-associated regions. We also recorded LFP in the vHPC to evaluate the related subcortical neural changes. Results revealed a sustained increase in the theta power in both mPFC and vHPC for the CL group. Our analysis also revealed an increase in mPFC-vHPC synchronization in the theta range over the stimulation sessions in the CL group, as measured by coherence and cross-correlation in the theta frequency band. The reinforcement of this circuit improved spatial decision-making performance in the subsequent behavioral results. Our findings provide direct evidence of the relationship between specific theta upregulation and SWM performance and suggest that theta oscillations are integral to cognitive processes. Overall, this study highlights the potential of adaptive CLNF systems in investigating neural dynamics in various brain circuits.
导航决策任务，如空间工作记忆（SWM），高度依赖于来自几个皮质和皮质下区域的信息整合。SWM 任务的表现与 theta 节律有关，包括与运动和记忆相关的低频振荡。腹侧海马体（vHPC）和内侧前额叶皮层（mPFC）的相互作用，反映在 theta 同步中，对于 SWM 期间的各种信息处理步骤至关重要。我们使用闭环神经反馈（CLNF）系统来上调 mPFC 中的 theta 功率，并研究其对动物模型中电路动力学和行为的影响。具体来说，我们假设增强 mPFC 中的 theta 节律功率可能会改善 SWM 表现。动物被分为三组：闭环（CL）、随机闭环（RL）和关闭（无刺激）。我们记录了 mPFC 中的局部场电位（LFP），同时根据皮质 theta 活动向外侧下丘脑（LH）传递电奖励刺激，LH 被认为是中央奖励相关区域之一。我们还记录了 vHPC 中的 LFP，以评估相关的皮质下神经变化。结果显示，CL 组的 mPFC 和 vHPC 中的 theta 功率都持续增加。我们的分析还显示，CL 组在刺激过程中，theta 频段的 mPFC-vHPC 同步性增加，这可以通过相干性和交叉相关性来衡量。该电路的增强改善了后续行为结果中的空间决策表现。我们的发现提供了特定的 theta 上调与 SWM 表现之间关系的直接证据，并表明 theta 振荡是认知过程的组成部分。总的来说，这项研究强调了自适应 CLNF 系统在研究各种大脑电路中的神经动力学方面的潜力。
