Spontaneous activity, memory replay and the default mode network

自发活动占大脑活动的大部分，可能是大脑信息处理的关键，但它的功能仍然很神秘。两个关键的自发活动过程是默认模式网络（DMN）和记忆重放，默认模式网络是一组在行为闲置期间最显着连接和活跃的区域，记忆重放是在经验期间发生的神经模式的自发重新激活。我将测试DMN在记忆重放过程中起关键作用的假设。这一理论如果得到证实，将为记忆研究带来重要的概念进步，因为它将提供一种支持复杂记忆表征形成和巩固的机制。对于默认模式网络领域，由于重放可以用作“罗塞塔石碑”来破译DMN执行的计算，超越了DMN研究的典型焦点-连接，动态和认知相关性。我将通过对整个小鼠皮层的自发神经活动进行实验研究来探索这一理论，从单神经元规模的大视场双光子成像和高容量电生理学，到运行记忆任务的动物的全皮层光学成像。我将通过量化传达的信息并评估其性质来描述网络动态以及记忆的编码和重放。我还将测量这些网络中的关键行为，并测试在自发活动中发生的神经元雪崩是否在远距离大脑区域传递信息中发挥作用。

Spontaneous activity accounts for most of what the brain does and is likely to be key for information processing in the brain, but its function is still quite mysterious. Two key spontaneous activity processes are the Default Mode Network (DMN), a set of areas that are most markedly connected and active during behavioural idleness, and memory replay, the spontaneous reactivation of neural patterns occurring during experience. I will test the hypothesis that the DMN plays a key role in memory replay processes. This theory, if confirmed, would bring important conceptual advances: to memory studies, as it would provide a mechanism supporting the formation and consolidation of complex memory representations. To the Default Mode Network field, as replay can be used as the "Rosetta Stone" to decipher the computations the DMN performs, moving beyond the connectivity, dynamics, and cognitive correlates, typical focus of DMN research. I will explore this theory by an experimental study of spontaneous neural activity over the whole mouse cortex, going from large field-of-view 2-photon imaging and high-volume electrophysiology for the single neuron scale, to whole-cortex optical imaging in animals running memory tasks. I will characterize the network dynamics and the encoding and replay of memories by quantifying conveyed information and assessing its nature. I will also measure critical behaviour in these networks, and test whether neuronal avalanches, that occur in spontaneous activity, play a role in conveying information across distant brain areas.