Background

The anterior nucleus of thalamus (ANT) has been suggested as an extended hippocampal system. The circuit of ANT and hippocampus has been widely demonstrated to be associated with memory function. Both lesions to each region and disrupting inter-regional information flow can induce working memory impairment. However, the role of this circuit in working memory precision remains unknown.

Objective

To test the role of the hippocampal-anterior thalamic pathway in working memory precision, we delivered intracranially electrical stimulation to the ANT. We hypothesize that ANT stimulation can improve working memory precision.

Methods

Presurgical epilepsy patients with depth electrodes in ANT and hippocampus were recruited to perform a color-recall working memory task. Participants were instructed to point out the color they were supposed to recall by clicking a point on the color wheel, while the intracranial EEG data were synchronously recorded. For randomly selected half trials, a bipolar electrical stimulation was delivered to the ANT electrodes.

Results

We found that compared to non-stimulation trials, working memory precision judgements were significantly improved for stimulation trials. ANT electrical stimulation significantly increased spectral power of gamma (30–100 Hz) oscillations and decreased interictal epileptiform discharges (IED) in the hippocampus. Moreover, the increased gamma power during the pre-stimulus and retrieval period predicted the improvement of working memory precision judgements.

Conclusion

ANT electrical stimulation can improve working memory precision judgements and modulate hippocampal gamma activity, providing direct evidence on the role of the human hippocampal-anterior thalamic axis in working memory precision.

中文翻译：

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前丘脑刺激提高工作记忆准确判断

背景

丘脑前核 (ANT) 被认为是一个扩展的海马系统。ANT和海马的回路已被广泛证明与记忆功能有关。每个区域的损伤和区域间信息流的中断都会导致工作记忆障碍。然而，该电路在工作记忆精度中的作用仍然未知。

客观的

为了测试海马-前丘脑通路在工作记忆精度中的作用，我们向 ANT 提供颅内电刺激。我们假设 ANT 刺激可以提高工作记忆的准确性。

方法

招募在 ANT 和海马中具有深度电极的术前癫痫患者来执行颜色回忆工作记忆任务。参与者被要求通过点击色轮上的一个点来指出他们应该回忆的颜色，同时同步记录颅内 EEG 数据。对于随机选择的半试验，双极电刺激被传递到 ANT 电极。

结果

我们发现，与非刺激试验相比，刺激试验的工作记忆精确度判断得到显着提高。ANT 电刺激显着增加了伽马 (30-100 Hz) 振荡的频谱功率，并减少了海马中的发作间期癫痫样放电 (IED)。此外，在刺激前和检索期间增加的伽马功率预示着工作记忆精确度判断的提高。

结论

ANT电刺激可以提高工作记忆精度判断，调节海马伽马活动，为人类海马-丘脑前轴在工作记忆精度中的作用提供直接证据。