Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
Cell. 2019 Apr 18;177(3):669-682.e24. doi: 10.1016/j.cell.2019.02.019. Epub 2019 Mar 28.
Throughout mammalian neocortex, layer 5 pyramidal (L5) cells project via the pons to a vast number of cerebellar granule cells (GrCs), forming a fundamental pathway. Yet, it is unknown how neuronal dynamics are transformed through the L5→GrC pathway. Here, by directly comparing premotor L5 and GrC activity during a forelimb movement task using dual-site two-photon Ca imaging, we found that in expert mice, L5 and GrC dynamics were highly similar. L5 cells and GrCs shared a common set of task-encoding activity patterns, possessed similar diversity of responses, and exhibited high correlations comparable to local correlations among L5 cells. Chronic imaging revealed that these dynamics co-emerged in cortex and cerebellum over learning: as behavioral performance improved, initially dissimilar L5 cells and GrCs converged onto a shared, low-dimensional, task-encoding set of neural activity patterns. Thus, a key function of cortico-cerebellar communication is the propagation of shared dynamics that emerge during learning.
在哺乳动物新皮质中，第 5 层（L5）锥体神经元通过脑桥投射到大量小脑颗粒细胞（GrC），形成一个基本的通路。然而，目前尚不清楚神经元的动力学是如何通过 L5→GrC 通路转换的。在这里，我们通过在使用双位点双光子 Ca 成像的前肢运动任务中直接比较运动前皮质 L5 和 GrC 的活动，发现对于熟练的小鼠，L5 和 GrC 的动力学非常相似。L5 细胞和 GrC 共享一组共同的任务编码活动模式，具有相似的响应多样性，并表现出与 L5 细胞之间的局部相关性相当的高相关性。慢性成像显示，这些动力学在学习过程中共同出现在大脑皮层和小脑：随着行为表现的提高，最初不同的 L5 细胞和 GrC 逐渐收敛到一个共同的、低维的、任务编码的神经网络活动模式集合上。因此，皮质-小脑通讯的一个关键功能是传播学习过程中出现的共享动力学。
