《科學》（20190118出版）一周論文導讀

知識 01-21

翻譯 | 宗華

Science, 18 JANUARY 2019, Vol 363, Issue 6424

《科學》2019年1月18日，第6424期363卷

《科學》（20190118出版）一周論文導讀

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生命科學Life Science

An amygdalar neural ensemble thatencodes theunpleasantness of pain

編碼疼痛不悅感的杏仁核神經元集群

作者：Gregory Corder, Biafra Ahanonu, Benjamin F. Grewe, et al

鏈接：

摘要：

疼痛是一種不愉快的經歷。大腦的情感神經迴路如何將這種令人厭惡的特性歸因於傷害性信息仍然未知。

通過對自由表現的小鼠遇到傷害性刺激進行延時體內鈣成像和神經活動操控，我們在編碼疼痛負面情感效價的杏仁基底外側核辨別出一個獨特的神經元集群。

令這個刺激疼痛的集群靜默緩解了疼痛的情緒—動機行為，但未改變對傷害性刺激、退避反射、焦慮或者獎勵的探測。

在經歷周圍神經性損傷後，無害刺激激活了這個刺激疼痛的神經元集群，從而驅動了同神經性疼痛相關的功能失調的感知變化，包括觸摸痛。

Abstract

Pain is an unpleasant experience. How the brain』s affective neural circuits attribute this aversive quality to nociceptive information remains unknown. By means of time-lapse in vivo calcium imaging and neural activity manipulation in freely behaving mice encountering noxious stimuli, we identified a distinct neural ensemble in the basolateral amygdala that encodes the negative affective valence of pain. Silencing this nociceptive ensemble alleviated pain affective-motivational behaviors without altering the detection of noxious stimuli, withdrawal reflexes, anxiety, or reward. Following peripheral nerve injury, innocuous stimuli activated this nociceptive ensemble to drive dysfunctional perceptual changes associated with neuropathic pain, including pain aversion to light touch (allodynia).

Cerebellar modulation of thereward circuitryand social behavior

小腦對獎勵迴路和社交行為的調控

作者：Ilaria Carta, Christopher H. Chen, Amanda L. Schott, et al

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摘要：

小腦涉及到諸多精神障礙，包括自閉症、精神分裂症和成癮。不過，其對這些疾病的貢獻尚未得到很好的理解。

我們通過小鼠試驗發現，小腦向蔡氏腹側被蓋區（VTA）發送直接的興奮性投射。VTA是大腦處理並且編碼獎勵的區域之一。

我們的數據揭示了小腦在控制獎勵迴路和社交行為中發揮的一直被忽視的重要作用。

Abstract

The cerebellum has been implicated in a number of nonmotor mental disorders such as autism spectrum disorder, schizophrenia, and addiction. However, its contribution to these disorders is not well understood. In mice, we found that the cerebellum sends direct excitatory projections to the ventral tegmental area (VTA), one of the brain regions that processes and encodes reward. Our data delineate a major, previously unappreciated role for the cerebellum in controlling the reward circuitry and social behavior.

Cortical column and whole-brainimaging withmolecular contrast and nanoscale resolution

擁有分子對比和納米尺度解析度的皮層柱和全腦成像

作者：Ruixuan Gao,ShohM. Asano, Srigokul Upadhyayula, et al

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摘要：

光學和電子顯微鏡在理解大腦複雜性方面取得了重要進展。

不過，光學顯微鏡在揭示亞細胞水平細節上存在解析度不足的問題，而電子顯微鏡缺少在毫米尺度或者更大尺度上對特定分子構成進行可視化的「生產量」和分子對比。

我們將擴展顯微鏡同晶格光片顯微鏡結合，對小鼠大腦皮層或整個果蠅大腦厚度的蛋白質之間的納米尺度空間關係進行了成像。

這些包括樹突棘的突觸蛋白質、沿著軸突的髓鞘形成以及每個蒼蠅大腦區域中多巴胺能神經元的突觸前密度。

Abstract

Optical and electron microscopy have made tremendous inroads toward understanding the complexity of the brain. However, optical microscopy offers insufficient resolution to reveal subcellular details, and electron microscopy lacks the throughput and molecular contrast to visualize specific molecular constituents over millimeter-scale or larger dimensions. We combined expansion microscopy and lattice light-sheet microscopy to image the nanoscale spatial relationships between proteins across the thickness of the mouse cortex or the entire Drosophila brain. These included synaptic proteins at dendritic spines, myelination along axons, and presynaptic densities at dopaminergic neurons in every fly brain region.

生物學Biology

Structural adaptations ofphoto synthetic complexI enable ferredoxin-dependent electron transfer

光合作用複合體I的結構自適應使依賴於鐵氧化還原蛋白的電子轉移成為可能

作者：Jan M. Schuller, James A. Birrell, Hideaki Tanaka, et al

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摘要：

光合作用複合體I使光系統I的循環性電子流成為可能。這是一個針對光合能量轉換的調控機制。

我們報告了來自藍細菌的光合作用複合體I的3.3埃解析度冷凍電鏡結構。模型揭示了促使光合電子載體——鐵氧化還原蛋白「捆綁」和電子轉移的結構自適應。

利用體外隔離組件模擬循環性電子流，我們證實，鐵氧化還原蛋白直接調停光系統I和複合體I之間的電子轉移，而不是利用諸如NADPH（磷酸醯胺腺嘌呤二核苷酸的縮減版）等中間體。

Abstract

Photosynthetic complex I enables cyclic electron flow around photosystem I, a regulatory mechanism for photo synthetic energy conversion. We report a 3.3-angstrom-resolution cryo–electron microscopy structure of photosynthetic complex I from the cyanobacterium Thermosynechococcus elongatus. The model reveals structural adaptations that facilitate binding and electron transfer from the photosynthetic electron carrier ferredoxin. By mimicking cyclic electron flow with isolated components in vitro, we demonstrate that ferredoxin directly mediates electron transfer between photosystem I and complex I, instead of using intermediates such as NADPH (the reduced form of nicotinamide adenine dinucleotide phosphate).

Agriculturally dominated landscapesreduce beephylogenetic diversity and pollination services

農業主導景觀減少蜜蜂系統發育多樣性和傳粉服務

作者：Heather Grab, Michael G. Branstetter, Nolan Amon, et al

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摘要：

土地利用變化威脅到全球生物多樣性，並且可能通過「偏愛」某些譜系重塑生命之樹。系統發育多樣性的喪失是否有損於生態系統服務仍然未知。

我們利用廣泛的基因組、群落和農作物數據集分析土地利用、傳粉者系統發育結構和作物生產之間的關係，彌補了這一知識缺口。

高度農業化景觀中的傳粉者群落少了2.3億年的進化歷史。這一損失同作物產量和質量減少存在強烈關聯。我們的研究將自然群落系統發育結構中景觀介導的變化同生態系統服務的擾亂關聯起來。

Abstract

Land-use change threatens global biodiversity and may reshape the tree of life by favoring some lineages over others. Whether phylogenetic diversity loss compromises ecosystem service delivery remains unknown. We address this knowledge gap using extensive genomic, community, and crop datasets to examine relationships among land use, pollinator phylogenetic structure, and crop production. Pollinator communities in highly agricultural landscapes contain 230 million fewer years of evolutionary history; this loss was strongly associated with reduced crop yield and quality. Our study links landscape–mediated changes in the phylogenetic structure of natural communities to the disruption of ecosystem services.

古地質學Paleogeology

Earth and Moon impact flux increased atthe endof the Paleozoic

地球和月球撞擊速率在古生代末期增加

作者：Sara Mazrouei, Rebecca R. Ghent, William F. Bottke, et al

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摘要：

地球撞擊坑記錄通常被認為存在偏差，因為侵蝕被認為會消除較老的坑，即便是在穩定的地形上。

考慮到相同的「射彈」群襲擊地球和月球，地球選擇效應可通過利用追溯直徑大於10公里、年齡小於10億年的月球撞擊坑的時間得到量化。

我們發現，約2.9億年前，撞擊速率增加了2.6倍。地球撞擊坑記錄顯示了類似結果，表明6.5億~3億年前的大型地球撞擊坑記錄的缺失源於較低的撞擊次數，而非保存中的偏差。

早於6.5億年前的地球撞擊坑的幾乎完全缺失或許表明了這一時間段附近大規模的全球尺度侵蝕事件。

Abstract

The terrestrial impact crater record is commonly assumed to be biased, with erosion thought to eliminate older craters, even on stable terrains. Given that the same projectile population strikes Earth and the Moon, terrestrial selection effects can be quantified by using a method to date lunar craters with diameters greater than 10 kilometers and younger than 1 billion years. We found that the impact rate increased by a factor of 2.6 about 290 million years ago. The terrestrial crater record shows similar results, suggesting that the deficit of large terrestrial craters between 300million and 650 million years ago relative to more recent times stems from a lower impact flux, not preservation bias. The almost complete absence of terrestrial craters older than 650 million years may indicate a massive global-scale erosion event near that time.

化學Chemistry

Prediction of higher-selectivitycatalysts bycomputer-driven workflow and machine learning

通過計算機驅動工作流程和機器學習預測較高選擇性催化劑

作者：Andrew F. Zahrt, Jeremy J. Henle, Brennan T. Rose, et al

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摘要：

傳統上，不對稱反應發展中的催化劑設計受經驗主義驅動。

其中，實驗主義者試圖定性識別結構模式以提高選擇性。機器學習演算法和化學信息學可通過識別大型數據集中否則將不可理解的模式，潛在地加速這一過程。

這裡，我們報告了一個計算機引導的工作流程用於手性催化劑的選擇。這是利用每個發展階段的化學信息學來實現的。

Abstract

Catalyst design in asymmetric reaction development has traditionally been driven by empiricism, wherein experimentalists attempt to qualitatively recognize structural patterns to improve selectivity. Machine learning algorithms and chemoinformatics can potentially accelerate this process by recognizing otherwise inscrutable patterns in large datasets. Herein we report a computationally guided workflow for chiral catalyst selection using chemoinformatics at every stage of development.

《科學》（20190118出版）一周論文導讀