小柯机器人

美国宾夕法尼亚大学Amita Sehgal及其研究组的最新研究发现，食物的可获得性决定了记忆巩固过程中对睡眠的需求。相关论文在线发表在2020年12月2日的《自然》杂志上。

研究人员揭示了一种基于电路的自适应机制，该机制使果蝇能够形成与睡眠有关和与睡眠无关的记忆。经过食性调节后进食的果蝇需要增加睡眠来巩固记忆，但是经过训练后饥饿的果蝇不需要睡眠就可以形成记忆。果蝇的记忆是由蘑菇体的前后α'/β'神经元介导，而饥饿时记忆的形成则是由内侧α'/β'神经元介导的。睡眠依赖性和睡眠非依赖性记忆受控于不同多巴胺能的神经元和相应蘑菇体输出神经元。

但是，睡眠和记忆是耦合的，因此睡眠依赖性记忆所需的蘑菇体神经元也可以促进睡眠。缺乏Neuropeptide F的果蝇即在饥饿情况下也会表现出与睡眠有关的记忆，这表明电路选择是由饥饿决定的。存储器电路的这种可塑性使果蝇能够在不断变化的环境中保留必要的信息。

据介绍，睡眠仍然是生物学中的一个未解谜团，人们对其基本功能了解甚少。通常认为睡眠最基本的功能是巩固记忆。但是，由于诸如饥饿之类的刺激会使生物体保持清醒和活跃，因此，形成睡眠非依赖的记忆巩固机制可能会带来进化上的优势。

附：英文原文

Title: Availability of food determines the need for sleep in memory consolidation

Author: Nitin S. Chouhan, Leslie C. Griffith, Paula Haynes, Amita Sehgal

Issue&Volume: 2020-12-02

Abstract: Sleep remains a major mystery of biology, with little understood about its basic function. One of the most commonly proposed functions of sleep is the consolidation of memory1,2,3. However, as conditions such as starvation require the organism to be awake and active4, the ability to switch to a memory consolidation mechanism that is not contingent on sleep may confer an evolutionary advantage. Here we identify an adaptive circuit-based mechanism that enables Drosophila to form sleep-dependent and sleep-independent memory. Flies fed after appetitive conditioning needed increased sleep for memory consolidation, but flies starved after training did not require sleep to form memories. Memory in fed flies is mediated by the anterior–posterior α′/β′ neurons of the mushroom body, while memory under starvation is mediated by medial α′/β′ neurons. Sleep-dependent and sleep-independent memory rely on distinct dopaminergic neurons and corresponding mushroom body output neurons. However, sleep and memory are coupled such that mushroom body neurons required for sleep-dependent memory also promote sleep. Flies lacking Neuropeptide F display sleep-dependent memory even when starved, suggesting that circuit selection is determined by hunger. This plasticity in memory circuits enables flies to retain essential information in changing environments.

DOI: 10.1038/s41586-020-2997-y

Source: https://www.nature.com/articles/s41586-020-2997-y

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
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