食物可獲得性決定了記憶鞏固過程中對睡眠的需求
作者:
小柯機器人發布時間:2020/12/3 16:56:23
美國賓夕法尼亞大學Amita Sehgal及其研究組的最新研究發現,食物的可獲得性決定了記憶鞏固過程中對睡眠的需求。相關論文在線發表在2020年12月2日的《自然》雜誌上。
研究人員揭示了一種基於電路的自適應機制,該機制使果蠅能夠形成與睡眠有關和與睡眠無關的記憶。經過食性調節後進食的果蠅需要增加睡眠來鞏固記憶,但是經過訓練後飢餓的果蠅不需要睡眠就可以形成記憶。果蠅的記憶是由蘑菇體的前後α'/β'神經元介導,而飢餓時記憶的形成則是由內側α'/β'神經元介導的。睡眠依賴性和睡眠非依賴性記憶受控於不同多巴胺能的神經元和相應蘑菇體輸出神經元。
但是,睡眠和記憶是耦合的,因此睡眠依賴性記憶所需的蘑菇體神經元也可以促進睡眠。缺乏Neuropeptide F的果蠅即在飢餓情況下也會表現出與睡眠有關的記憶,這表明電路選擇是由飢餓決定的。存儲器電路的這種可塑性使果蠅能夠在不斷變化的環境中保留必要的信息。
據介紹,睡眠仍然是生物學中的一個未解謎團,人們對其基本功能了解甚少。通常認為睡眠最基本的功能是鞏固記憶。但是,由於諸如飢餓之類的刺激會使生物體保持清醒和活躍,因此,形成睡眠非依賴的記憶鞏固機制可能會帶來進化上的優勢。
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