A transient postnatal quiescent period precedes emergence of mature cortical dynamics.
A transient postnatal quiescent period precedes emergence of mature cortical dynamics.
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DOI：
10.7554/elife.69011
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发表时间：
2021-07-23
期刊：
影响因子：
7.7
通讯作者：
Gelinas JN
中科院分区：
文献类型：
--
作者：
Domínguez S;Ma L;Yu H;Pouchelon G;Mayer C;Spyropoulos GD;Cea C;Buzsáki G;Fishell G;Khodagholy D;Gelinas JN
成熟的神经网络同步和整合时空活动模式以支持认知。这些活动模式和功能的出现被认为是发育调节的，但神经网络执行复杂计算的出生后时间过程仍然未知。我们研究了大规模的突触和细胞活动模式的发展，在整个发展中使用高时空分辨率在体内电生理学在未成熟的小鼠。我们发现，成熟的皮质过程出现迅速，同时离散，但不稳定的过渡期后，在出生后第二周的啮齿动物发育开始。过渡的特点是相对的神经静止，之后空间分布，时间精确，内部组织的活动发生。我们在人类中展示了类似的发展轨迹，这表明了一种进化上保守的机制，可以促进网络操作的转变。我们假设，这短暂的静止期是一个必要的协调皮层网络随后出现。年轻动物的大脑可能需要几个月甚至几年的时间来发展和完善复杂的神经网络，这些神经网络是记忆、规划和决策等认知能力的基础。虽然支持这些功能的属性已经有了很好的文档记录，但对于它们在开发过程中是如何出现的却知之甚少。因此，Domínguez，Ma，Yu等人开始确定这些特性何时开始在小鼠中形成，使用轻型电极网络记录睡眠中新生幼崽的大脑活动。这些网的设计是为了避免打扰动物或损害它们脆弱的大脑。记录显示，在出生后的头几周，大脑活动模式与成年人相似。然而，就在此之前，幼崽的大脑经历了一段短暂的活动减少期：这种平静似乎标志着从不成熟到更成熟的运作模式的转变。在这一停顿之后，小鼠大脑中的神经元显示出协调的放电模式，让人想起在成年人中看到的那些。通过使用头皮传感器监测人类婴儿的大脑，Domínguez，Ma，Yu等人表明，在婴儿出生后的头几个月也会发生类似的转变，这表明大脑可能通过跨物种保留的过程而成熟。总的来说，过渡前活动的相对平静可能标志着神经网络获得成熟特性的时间;因此，在未来，它可能被用于诊断和监测认知发育延迟的个体。
Mature neural networks synchronize and integrate spatiotemporal activity patterns to support cognition. Emergence of these activity patterns and functions is believed to be developmentally regulated, but the postnatal time course for neural networks to perform complex computations remains unknown. We investigate the progression of large-scale synaptic and cellular activity patterns across development using high spatiotemporal resolution in vivo electrophysiology in immature mice. We reveal that mature cortical processes emerge rapidly and simultaneously after a discrete but volatile transition period at the beginning of the second postnatal week of rodent development. The transition is characterized by relative neural quiescence, after which spatially distributed, temporally precise, and internally organized activity occurs. We demonstrate a similar developmental trajectory in humans, suggesting an evolutionarily conserved mechanism that could facilitate a transition in network operation. We hypothesize that this transient quiescent period is a requisite for the subsequent emergence of coordinated cortical networks. It can take several months, or even years, for the brain of a young animal to develop and refine the complex neural networks which underpin cognitive abilities such as memory, planning, and decision making. While the properties that support these functions have been well-documented, less is known about how they emerge during development. Domínguez, Ma, Yu et al. therefore set out to determine when exactly these properties began to take shape in mice, using lightweight nets of electrodes to record brain activity in sleeping newborn pups. The nets were designed to avoid disturbing the animals or damaging their fragile brains. The recordings showed that patterns of brain activity similar to those seen in adults emerged during the first couple of weeks after birth. Just before, however, the brains of the pups went through a brief period of reduced activity: this lull seemed to mark a transition from an immature to a more mature mode of operation. After this pause, neurons in the mouse brains showed coordinated patterns of firing reminiscent of those seen in adults. By monitoring the brains of human babies using scalp sensors, Domínguez, Ma, Yu et al. showed that a similar transition also occurs in infants during their first few months of life, suggesting that brains may mature via a process retained across species. Overall, the relative lull in activity before transition may mark when neural networks gain mature properties; in the future, it could therefore potentially be used to diagnose and monitor individuals with delayed cognitive development.