小柯机器人

美国麻省理工学院Mriganka Sur、Vincent Breton-Provencher等研究人员合作揭示学习行为中去甲肾上腺素的时空动态变化。该研究于2022年6月1日在线发表于国际一流学术期刊《自然》。

研究人员表示，丘脑（LC）释放的去甲肾上腺素是一种无处不在的神经调节剂，与多种功能有关，包括唤醒，行动和感觉增益，和学习。在LC中表达去甲肾上腺素的神经元（LC-NA）的激活是否以及如何促进特定行为的不同组成部分尚不清楚。

研究人员发现，LC-NA活动显示出不同的时空动态，以便在学习行为期间实现两种功能：促进任务执行和编码强化，从而提高表现的准确性。为了研究这些功能，研究人员在小鼠中使用了一项行为任务，对听觉刺激的检测和任务表现进行分级。光遗传失活的LC表明，LC-NA的活动对任务的执行和优化都有因果关系。

使用照片标记、双光子显微内窥镜和双光子输出监测对LC-NA神经元的定向记录表明，LC-NA的瞬时激活在行为执行之前和强化之后。阶段性活动的这两个组成部分在LC-NA皮层输出中是异质性的，如行为反应信号在运动皮层中较高，有利于任务的执行，而负强化信号则广泛分布于皮层区域，提高了后续试验的反应敏感性。因此，LC输出的模块化目标实现了多样化的功能，即一些去甲肾上腺素信号被隔离在目标之间，而其他信号则广泛分布。

附：英文原文

Title: Spatiotemporal dynamics of noradrenaline during learned behaviour

Author: Breton-Provencher, Vincent, Drummond, Gabrielle T., Feng, Jiesi, Li, Yulong, Sur, Mriganka

Issue&Volume: 2022-06-01

Abstract: Noradrenaline released from the locus coeruleus (LC) is a ubiquitous neuromodulator1,2,3,4 that has been linked to multiple functions including arousal5,6,7,8, action and sensory gain9,10,11, and learning12,13,14,15,16. Whether and how activation of noradrenaline-expressing neurons in the LC (LC-NA) facilitates different components of specific behaviours is unknown. Here we show that LC-NA activity displays distinct spatiotemporal dynamics to enable two functions during learned behaviour: facilitating task execution and encoding reinforcement to improve performance accuracy. To examine these functions, we used a behavioural task in mice with graded auditory stimulus detection and task performance. Optogenetic inactivation of the LC demonstrated that LC-NA activity was causal for both task execution and optimization. Targeted recordings of LC-NA neurons using photo-tagging, two-photon micro-endoscopy and two-photon output monitoring showed that transient LC-NA activation preceded behavioural execution and followed reinforcement. These two components of phasic activity were heterogeneously represented in LC-NA cortical outputs, such that the behavioural response signal was higher in the motor cortex and facilitated task execution, whereas the negative reinforcement signal was widely distributed among cortical regions and improved response sensitivity on the subsequent trial. Modular targeting of LC outputs thus enables diverse functions, whereby some noradrenaline signals are segregated among targets, whereas others are broadly distributed.

DOI: 10.1038/s41586-022-04782-2

Source: https://www.nature.com/articles/s41586-022-04782-2

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
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