The rapid developmental rise of somatic inhibition disengages hippocampal dynamics from self-motion.
The rapid developmental rise of somatic inhibition disengages hippocampal dynamics from self-motion.
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DOI：
10.7554/elife.78116
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发表时间：
2022-07-20
期刊：
影响因子：
7.7
通讯作者：
Picardo MA
中科院分区：
文献类型：
--
作者：
Dard RF;Leprince E;Denis J;Rao Balappa S;Suchkov D;Boyce R;Lopez C;Giorgi-Kurz M;Szwagier T;Dumont T;Rouault H;Minlebaev M;Baude A;Cossart R;Picardo MA
在早产儿和新生啮齿动物中记录的早期电生理脑振荡最初主要是由自下而上的感觉运动活动驱动的，只有后来才能与外部输入分离。这是大多数发育中的大脑区域的一个标志，包括海马体，在成年人的大脑中，海马体的功能是将外部输入整合到内部动态中。这种发展脱离外部输入可能是正确发展认知内部模型的基本步骤。尽管它的重要性，发展的时间轴和电路的基础，这种脱离仍然未知。为了解决这个问题，我们在非麻醉幼崽中使用双光子钙成像研究了小鼠出生后前两周发育期间CA 1动力学和基础电路的每日演变。我们发现，出生后的第一周结束时，在CA1的自我运动的代表性突然转变。事实上，大多数CA1锥体细胞在出生后第一周结束时通过自发运动从激活切换到抑制，而大多数GABA能神经元在整个期间保持正调制。这种快速转换发生在2天内，并遵循局部躯体GABA能神经支配的快速解剖和功能激增。所观察到的动态变化是一致的两个人口模型进行了加强抑制。我们认为，这种突然的发展转变开创了内部海马动力学的出现。
Early electrophysiological brain oscillations recorded in preterm babies and newborn rodents are initially mostly driven by bottom-up sensorimotor activity and only later can detach from external inputs. This is a hallmark of most developing brain areas, including the hippocampus, which, in the adult brain, functions in integrating external inputs onto internal dynamics. Such developmental disengagement from external inputs is likely a fundamental step for the proper development of cognitive internal models. Despite its importance, the developmental timeline and circuit basis for this disengagement remain unknown. To address this issue, we have investigated the daily evolution of CA1 dynamics and underlying circuits during the first two postnatal weeks of mouse development using two-photon calcium imaging in non-anesthetized pups. We show that the first postnatal week ends with an abrupt shift in the representation of self-motion in CA1. Indeed, most CA1 pyramidal cells switch from activated to inhibited by self-generated movements at the end of the first postnatal week, whereas the majority of GABAergic neurons remain positively modulated throughout this period. This rapid switch occurs within 2 days and follows the rapid anatomical and functional surge of local somatic GABAergic innervation. The observed change in dynamics is consistent with a two-population model undergoing a strengthening of inhibition. We propose that this abrupt developmental transition inaugurates the emergence of internal hippocampal dynamics.