James Clark Center for Biomedical Engineering, Stanford University, Stanford, CA, USA.
CNC Program, Stanford University, Stanford, CA, USA.
Nature. 2022 May;605(7911):713-721. doi: 10.1038/s41586-022-04724-y. Epub 2022 May 19.
Reliable sensory discrimination must arise from high-fidelity neural representations and communication between brain areas. However, how neocortical sensory processing overcomes the substantial variability of neuronal sensory responses remains undetermined. Here we imaged neuronal activity in eight neocortical areas concurrently and over five days in mice performing a visual discrimination task, yielding longitudinal recordings of more than 21,000 neurons. Analyses revealed a sequence of events across the neocortex starting from a resting state, to early stages of perception, and through the formation of a task response. At rest, the neocortex had one pattern of functional connections, identified through sets of areas that shared activity cofluctuations. Within about 200 ms after the onset of the sensory stimulus, such connections rearranged, with different areas sharing cofluctuations and task-related information. During this short-lived state (approximately 300 ms duration), both inter-area sensory data transmission and the redundancy of sensory encoding peaked, reflecting a transient increase in correlated fluctuations among task-related neurons. By around 0.5 s after stimulus onset, the visual representation reached a more stable form, the structure of which was robust to the prominent, day-to-day variations in the responses of individual cells. About 1 s into stimulus presentation, a global fluctuation mode conveyed the upcoming response of the mouse to every area examined and was orthogonal to modes carrying sensory data. Overall, the neocortex supports sensory performance through brief elevations in sensory coding redundancy near the start of perception, neural population codes that are robust to cellular variability, and widespread inter-area fluctuation modes that transmit sensory data and task responses in non-interfering channels.
可靠的感觉辨别能力必须源于高保真的神经表示和大脑区域之间的通讯。然而，新皮层感觉处理如何克服神经元感觉反应的大量可变性仍然不确定。在这里，我们在执行视觉辨别任务的小鼠中同时对八个新皮层区域进行成像，并在五天内进行成像，对超过 21000 个神经元进行了纵向记录。分析揭示了新皮层中从静息状态到感知早期阶段再到任务反应形成的一系列事件。在休息时，新皮层具有一种功能连接模式，通过共享活动共变的区域集来识别。在感觉刺激开始后大约 200 毫秒内，这种连接重新排列，不同的区域共享共变和与任务相关的信息。在这个短暂的状态（大约 300 毫秒持续时间）中，区域间的感觉数据传输和感觉编码的冗余都达到了峰值，反映了与任务相关的神经元之间相关波动的短暂增加。在刺激开始后大约 0.5 秒，视觉表示达到了更稳定的形式，其结构对单个细胞反应中明显的日常变化具有鲁棒性。大约在刺激呈现 1 秒后，全局波动模式向每个检查区域传达了老鼠即将做出的反应，并且与携带感觉数据的模式正交。总的来说，新皮层通过在感知开始时短暂提高感觉编码冗余来支持感觉表现，对细胞变异性具有鲁棒性的神经群体代码，以及广泛的区域间波动模式，这些模式以非干扰的通道传输感觉数据和任务响应。
