日本理研脑科学中心Thomas J. McHugh和Shuo Chen研究组合作发现下丘脑新颖信号调节海马记忆。2020年9月30日出版的《自然》杂志发表了这项成果。
他们确定上丘脑上核（SuM）为下丘脑中的新枢纽。SuM区域的独特之处在于，它不仅可以对新的刺激做出广泛反应，而且可以将不同类型的信息隔离并选择性地输送到离散的皮质靶标（海马的齿状回和CA2区域），以调节记忆处理。
使用新的转基因小鼠品系SuM-Cre，他们发现投射到齿状回的SuM神经元被新环境激活，而SuM–CA2回路优先被新社交活动激活。基于回路的操纵表明，在这些预测中，不同新颖性渠道改变了海马环境或社交记忆。新颖信号的这种特定于内容的输送表示一种先前未知的机制，该机制使下丘脑能够灵活地调节认知的选定成分。
据介绍，识别与先前经验不一致的信息的能力对于生存至关重要。因此，新颖的信号已经在哺乳动物的大脑中进化出来，以增强注意力、感知力和记忆力。尽管已经充分确定了诸如腹侧被盖区和蓝斑等区域在广泛的信号新颖性中的重要性，但是这些弥散的单胺能递质尚未被证实能够传达驱动它们刺激类型的具体信息。大脑中不同类型的新奇事物（例如环境和社会新奇事物）是否经过不同的处理和传递是未知的。
附：英文原文
Title: A hypothalamic novelty signal modulates hippocampal memory
Author: Shuo Chen, Linmeng He, Arthur J. Y. Huang, Roman Boehringer, Vincent Robert, Marie E. Wintzer, Denis Polygalov, Adam Z. Weitemier, Yanqiu Tao, Mingxiao Gu, Steven J. Middleton, Kana Namiki, Hiroshi Hama, Ludivine Therreau, Vivien Chevaleyre, Hiroyuki Hioki, Atsushi Miyawaki, Rebecca A. Piskorowski, Thomas J. McHugh
Issue&Volume: 2020-09-30
Abstract: The ability to recognize information that is incongruous with previous experience is critical for survival. Novelty signals have therefore evolved in the mammalian brain to enhance attention, perception and memory1,2. Although the importance of regions such as the ventral tegmental area3,4 and locus coeruleus5 in broadly signalling novelty is well-established, these diffuse monoaminergic transmitters have yet to be shown to convey specific information on the type of stimuli that drive them. Whether distinct types of novelty, such as contextual and social novelty, are differently processed and routed in the brain is unknown. Here we identify the supramammillary nucleus (SuM) as a novelty hub in the hypothalamus6. The SuM region is unique in that it not only responds broadly to novel stimuli, but also segregates and selectively routes different types of information to discrete cortical targets—the dentate gyrus and CA2 fields of the hippocampus—for the modulation of mnemonic processing. Using a new transgenic mouse line, SuM-Cre, we found that SuM neurons that project to the dentate gyrus are activated by contextual novelty, whereas the SuM–CA2 circuit is preferentially activated by novel social encounters. Circuit-based manipulation showed that divergent novelty channelling in these projections modifies hippocampal contextual or social memory. This content-specific routing of novelty signals represents a previously unknown mechanism that enables the hypothalamus to flexibly modulate select components of cognition.
DOI: 10.1038/s41586-020-2771-1
Source: https://www.nature.com/articles/s41586-020-2771-1
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/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
