攝入機械感覺反饋控制的神經迴路機制
作者:
小柯機器人發布時間:2020/4/14 13:26:31
韓國首爾國立大學Sung-Yon Kim團隊近日取得一項新成果。他們的研究揭示攝入機械感覺反饋控制的神經迴路機制。該研究於2020年4月8日發表於《自然》雜誌上。
研究組表明,在小鼠中,表達前強啡肽基因的臂旁神經核中的神經元(以下稱PBPdyn神經元)利用上消化道產生的機械感覺信號來監測液體和固體的攝入。多數個體PBPdyn神經元通過攝入以及對口和胃的刺激而被激活,這表明了消化道不同部位所整合的感覺信號的表現。PBPdyn神經元在解剖學上通過顱骨和脊髓途徑連接到消化系統。
在這些途徑中,迷走神經將胃擴張信號傳遞給PBPdyn神經元。收到這些信號後,這些神經元會產生厭惡和持續的食慾抑制信號,從而部分地通過向心室下丘腦發出信號來阻止進食和飲水(充分重現胃擴張的症狀)。相比之下,僅當存在攝取驅動時,抑制相同的PBPdyn神經元群體才會引起過度消耗,這證實了這些神經元會介導負反饋信號。他們的發現揭示了一種神經機制,它是消化的機械感覺監測和消化道擴張時攝入行為的負反饋控制的基礎。
據了解,從消化道到大腦的機械感覺反饋對於限制過多的食物和水攝入至關重要,但是潛在的腸-腦溝通途徑和機制仍然知之甚少。
附:英文原文
Title: A neural circuit mechanism for mechanosensory feedback control of ingestion
Author: Dong-Yoon Kim, Gyuryang Heo, Minyoo Kim, Hyunseo Kim, Ju Ae Jin, Hyun-Kyung Kim, Sieun Jung, Myungmo An, Benjamin H. Ahn, Jong Hwi Park, Han-Eol Park, Myungsun Lee, Jung Weon Lee, Gary J. Schwartz, Sung-Yon Kim
Issue&Volume: 2020-04-08
Abstract: Mechanosensory feedback from the digestive tract to the brain is critical for limiting excessive food and water intake, but the underlying gut–brain communication pathways and mechanisms remain poorly understood1,2,3,4,5,6,7,8,9,10,12. Here we show that, in mice, neurons in the parabrachial nucleus that express the prodynorphin gene (hereafter, PBPdyn neurons) monitor the intake of both fluids and solids, using mechanosensory signals that arise from the upper digestive tract. Most individual PBPdyn neurons are activated by ingestion as well as the stimulation of the mouth and stomach, which indicates the representation of integrated sensory signals across distinct parts of the digestive tract. PBPdyn neurons are anatomically connected to the digestive periphery via cranial and spinal pathways; we show that, among these pathways, the vagus nerve conveys stomach-distension signals to PBPdyn neurons. Upon receipt of these signals, these neurons produce aversive and sustained appetite-suppressing signals, which discourages the initiation of feeding and drinking (fully recapitulating the symptoms of gastric distension) in part via signalling to the paraventricular hypothalamus. By contrast, inhibiting the same population of PBPdyn neurons induces overconsumption only if a drive for ingestion exists, which confirms that these neurons mediate negative feedback signalling. Our findings reveal a neural mechanism that underlies the mechanosensory monitoring of ingestion and negative feedback control of intake behaviours upon distension of the digestive tract.
DOI: 10.1038/s41586-020-2167-2
Source: https://www.nature.com/articles/s41586-020-2167-2