Section on Critical Brain Dynamics, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA.
Cell Rep. 2024 Feb 27;43(2):113762. doi: 10.1016/j.celrep.2024.113762. Epub 2024 Feb 10.
In the mammalian cortex, even simple sensory inputs or movements activate many neurons, with each neuron responding variably to repeated stimuli-a phenomenon known as trial-by-trial variability. Understanding the spatial patterns and dynamics of this variability is challenging. Using cellular 2-photon imaging, we study visual and auditory responses in the primary cortices of awake mice. We focus on how individual neurons' responses differed from the overall population. We find consistent spatial correlations in these differences that are unique to each trial and linearly scale with the cortical area observed, a characteristic of critical dynamics as confirmed in our neuronal simulations. Using chronic multi-electrode recordings, we observe similar scaling in the prefrontal and premotor cortex of non-human primates during self-initiated and visually cued motor tasks. These results suggest that trial-by-trial variability, rather than being random noise, reflects a critical, fluctuation-dominated state in the cortex, supporting the brain's efficiency in processing information.
在哺乳动物大脑皮层中，即使是简单的感官输入或运动也会激活许多神经元，每个神经元对重复刺激的反应各不相同——这种现象被称为逐次变异性。理解这种变异性的空间模式和动态是具有挑战性的。使用细胞双光子成像，我们研究了清醒小鼠初级皮层的视觉和听觉反应。我们专注于个体神经元的反应如何与总体种群不同。我们发现这些差异中的一致空间相关性是每个试验特有的，并与观察到的皮质面积呈线性比例，这是我们神经元模拟中确认的临界动力学的特征。使用慢性多电极记录，我们在非人类灵长类动物的前额叶和前运动皮层中观察到类似的在自我发起和视觉提示运动任务期间的缩放。这些结果表明，逐次变异性不是随机噪声，而是反映了皮层中的一种关键、波动主导状态，支持大脑在处理信息方面的效率。
