Bournemouth University

寒冷的冬天，保暖是第一要义，但不少人却保持着洗冷水澡或是冬泳的爱好，是什么原因让人们热爱着这项“折磨人”的习惯或运动呢？近日，来自朴茨茅斯大学，伯恩茅斯大学和多塞特大学医院（UHD）的研究小组首次观察到，当一个人的身体浸入冷水中后，大脑不同部位会相互作用产生变化。这些发现解释了为什么人们在冬泳或洗冷水澡后经常感到更加乐观和活跃。该研究题为“Short-Term Head-Out Whole-Body Cold-Water Immersion Facilitates Positive Affect and Increases Interaction between Large-Scale Brain Networks”，发表在Biology杂志。 来源：https://doi.org/10.3390/biology12020211近年来，冷水浸泡（CWI）、户外游泳或冷水淋浴的普及程度越来越高。以往的数据表明这些活动具有一定风险，但是最近几年的研究表明其对我们的健康有一定好处。在一项观察冷水浸泡对生理反应影响的研究中发现，即使短暂暴露于冷水中也会引发一系列适应性生化和生理反应，这些反应对免疫系统，血流动力学和运动功能都有益。大量证据表明，经常在冷水中游泳可减轻疲劳，减轻抑郁症状，并改善总体健康状况。此外，一些研究报告了冷水浸泡对提升情绪和增加积极情绪状态的直接影响。例如，参加为期10周游泳项目的受试者心境状态积极性显著增加，消极性心态显著降低。尽管冷水浸泡后的生化变化有助于即时的情绪提升，但在这些影响下潜在的神经机制仍然未知。积极影响可以理解为一个人感到热情、活跃的程度。高积极影响反映了高能量、注意力和愉快的参与。相反，负面情绪被描述为人对环境的痛苦经历和负面反应，包括紧张、恐惧、愤怒和内疚。在本研究中，作者收集了一组不习惯全身冷水浸泡的人在测试前后的行为和神经影像学数据来验证这些假设。研究的方法论方法源于最近开发的一个框架，该框架根据同步大脑活动模式将大脑的时空组织表征为大规模网络。在无任务条件下使用静息状态连接建立了代表功能性MRI信号同步波动中的统计依赖性的模式。来源：https://doi.org/10.3390/biology12020211参与者的招募资格是：（i）没有任何类型的慢性疼痛；（ii）不使用药物；（iii）无躯体、神经、精神或物质使用障碍病史；（iv）未怀孕（女性）；（v）在过去 18-20 个月内未接触冷水浸泡每个参与者都来到伯恩茅斯大学的医学成像和可视化研究所，首先接受了初步的功能磁共振扫描。然后，他们将浸入20摄氏度的水池中五分钟，同时心电图和呼吸设备测量他们身体的生理反应。在快速烘干后，他们接受了第二次功能磁共振扫描，以便研究人员可以寻找大脑活动的任何变化。对冷水生理反应的记录显示参与者的心肺功能发生变化，表明所有参与者都经历过冷休克，这是一种身体突然浸入冷水（低于15℃）时产生的短时间的本能反应（并不是医学意义上的“休克”，只是身体表现出来的应激反应和休克前期相似，除了血管收缩外，并没有身体血容积的变化）。自我报告情绪问卷的结果显示，冷水浸泡后积极影响显著增加，负面影响减少。研究数据表明，积极影响的变化主要与警觉性提高有关，感觉更加鼓舞，积极，专注和自豪，而负面影响的减少反映了紧张和痛苦的程度降低。来源：https://doi.org/10.3390/biology12020211接下来，研究人员测试了冷水浸泡前后积极影响评分的差异之间的关联。来源：https://doi.org/10.3390/biology12020211基于网络的结果（NBS）证明暴露于冷水与多个神经网络的时间相关性有关，包括默认模式网络的内侧前额叶皮层，左前岛叶，左前额叶皮层和显著网络的前扣带皮层，以及DMN的左外侧顶叶部分。来源：https://doi.org/10.3390/biology12020211总之，该研究表明，接触冷水后情绪会更积极，与大脑特定部位之间的连接发生变化有关，特别是内侧前额叶皮层和顶叶皮层，这些是大脑控制情绪的部分，参与情感过程的“核心”网络之间的相互作用支持积极影响，负面影响的变化与阈值降低的交互网络的分布式组件相关联。冷水浸泡后正负影响的变化相互独立，支持情感处理的二价模型。这些发现将有助于对焦虑症、抑郁症等疾病的疗法的开发。很多人认为冷水澡对身体不好“寒气重”，其实它会为身体的免疫、消化和循环系统带来一系列健康益处。它利用身体的自然愈合能力，激活神经系统和荷尔蒙，从而显著改善我们的生理机能。如今，很多人面对生活中的各种压力，我们不妨试试冲个凉水澡，既能适度提高免疫力，也能帮助我们解压，拥有乐观的生活心态。（当然也需要根据个人体质来选择哦！）来源：https://www.mdpi.com/2079-7737/12/2/211撰稿 | Cathy编辑 | cici精彩推荐：1、合成技术新突破！《ACS合成生物学》：创新合成生物传感器或可创建芯片上的“感觉器官”！2、拥抱为什么能让人身心愉悦？Cell：首次发现皮肤与大脑之间的重要神经通路！3、类器官重大进展！Cell子刊：复旦大学夏明宇团队成功建立首个具有功能性突触的耳蜗类器官，再现听觉单元早期发育！4、靠谱！《欧洲心脏杂志》大型国际研究揭示：“试管婴儿”心脏代谢健康结果与自然受孕儿童无异！5、世界首次修复肾细胞！Nature子刊：新型再生疗法可恢复受损的肾功能，IL11或成为治疗新靶点！

New research transforms our understanding of the circumstances and timing of the domestication of chickens, their spread across Asia into the west, and reveals the changing way in which they were perceived in societies over the past 3,500 years. New research transforms our understanding of the circumstances and timing of the domestication of chickens, their spread across Asia into the west, and reveals the changing way in which they were perceived in societies over the past 3,500 years. Experts have found that an association with rice farming likely started a process that has led to chickens becoming one of the world's most numerous animals. They have also found evidence that chickens were initially regarded as exotica, and only several centuries later used as a source of 'food'. Previous efforts have claimed that chickens were domesticated up to 10,000 years ago in China, Southeast Asia, or India, and that chickens were present in Europe over 7,000 years ago. The new studies show this is wrong, and that the driving force behind chicken domestication was the arrival of dry rice farming into southeast Asia where their wild ancestor, the red jungle fowl, lived. Dry rice farming acted as a magnet drawing wild jungle fowl down from the trees, and kickstarting a closer relationship between people and the jungle fowl that resulted in chickens. This domestication process was underway by around 1,500 BC in the Southeast Asia peninsula. The research suggests that chickens were then transported first across Asia and then throughout the Mediterranean along routes used by early Greek, Etruscan and Phoenician maritime traders. During the Iron Age in Europe, chickens were venerated and generally not regarded as food. The studies have shown that several of the earliest chickens are buried alone and un-butchered, and many are also found buried with people. Males were often buried with cockerels and females with hens. The Roman Empire then helped to popularise chickens and eggs as food. For example, in Britain, chickens were not regularly consumed until the third century AD, mostly in urban and military sites. The international team of experts re-evaluated chicken remains found in more than 600 sites in 89 countries. They examined the skeletons, burial location and historical records regarding the societies and cultures where the bones were found. The oldest bones of a definite domestic chicken were found at Neolithic Ban Non Wat in central Thailand, and date to between 1,650 and 1,250 BC. The team also used radiocarbon dating to establish the age of 23 of the proposed earliest chickens found in western Eurasia and north-west Africa. Most of the bones were far more recent than previously thought. The results dispel claims of chickens in Europe before the first millennium BC and indicate that they did not arrive until around 800 BC. Then, after arriving in the Mediterranean region, it took almost 1,000 years longer for chickens to become established in the colder climates of Scotland, Ireland, Scandinavia and Iceland. The two studies, published in the journals Antiquity and Proceedings of the National Academy of Sciences, were carried out by academics at the universities of Exeter, Munich, Cardiff, Oxford, Bournemouth, Toulouse, and universities and institutes in Germany, France and Argentina. Professor Naomi Sykes, from the University of Exeter, said: "Eating chickens is so common that people think we have never not eaten them. Our evidence shows that our past relationship with chickens was far more complex, and that for centuries chickens were celebrated and venerated." Professor Greger Larson, from the University of Oxford, said: "This comprehensive re-evaluation of chickens firstly demonstrates how wrong our understanding of the time and place of chicken domestication was. And even more excitingly, we show how the arrival of dry rice agriculture acted as a catalyst for both the chicken domestication process and its global dispersal." Dr Julia Best, from Cardiff University said: "This is the first time that radiocarbon dating has been used on this scale to determine the significance of chickens in early societies. Our results demonstrate the need to directly date proposed early specimens, as this allows us the clearest picture yet of our early interactions with chickens." Professor Joris Peters, from LMU Munich and the Bavarian State Collection of Palaeoanatomy, said: "With their overall highly adaptable but essentially cereal-based diet, sea routes played a particularly important role in the spread of chickens to Asia, Oceania, Africa and Europe." Dr Ophélie Lebrasseur, from the CNRS/Université Toulouse Paul Sabatier and the Instituto Nacional de Antropología y Pensamiento Latinoamericano, said: "The fact that chickens are so ubiquitous and popular today, and yet were domesticated relatively recently is startling. Our research highlights the importance of robust osteological comparisons, secure stratigraphic dating and placing early finds within their broader cultural and environmental context." Professor Mark Maltby, from Bournemouth University, said, "These studies show the value of museums and the importance of archaeological materials to reveal our past."