Robarts Research Institute, University of Western Ontario, London, ON, Canada.
Brain and Mind Institute, University of Western Ontario, London, ON, Canada.
Nat Commun. 2024 May 25;15(1):4471. doi: 10.1038/s41467-024-48664-9.
Working memory (WM) is the ability to maintain and manipulate information 'in mind'. The neural codes underlying WM have been a matter of debate. We simultaneously recorded the activity of hundreds of neurons in the lateral prefrontal cortex of male macaque monkeys during a visuospatial WM task that required navigation in a virtual 3D environment. Here, we demonstrate distinct neuronal activation sequences (NASs) that encode remembered target locations in the virtual environment. This NAS code outperformed the persistent firing code for remembered locations during the virtual reality task, but not during a classical WM task using stationary stimuli and constraining eye movements. Finally, blocking NMDA receptors using low doses of ketamine deteriorated the NAS code and behavioral performance selectively during the WM task. These results reveal the versatility and adaptability of neural codes supporting working memory function in the primate lateral prefrontal cortex.
工作记忆（WM）是在“脑海中”维持和操作信息的能力。工作记忆的神经编码一直是争论的焦点。我们在雄性猕猴的外侧前额叶皮层同时记录了数百个神经元的活动，这些神经元在一个需要在虚拟 3D 环境中导航的视空间 WM 任务中。在这里，我们证明了不同的神经元激活序列（NAS）可以编码虚拟环境中记住的目标位置。在虚拟现实任务中，这个 NAS 代码比记忆位置的持续放电代码表现更好，但在使用固定刺激和限制眼球运动的经典 WM 任务中则不然。最后，使用低剂量氯胺酮阻断 NMDA 受体选择性地在 WM 任务中恶化了 NAS 代码和行为表现。这些结果揭示了灵长类动物外侧前额叶皮层支持工作记忆功能的神经编码的多功能性和适应性。
