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Astrocytes improve decision-making
Recent data from Dr. Perea’s group suggested that, apart from the role of astrocytes in the maintenance of synaptic transmission, these cells can sense and respond to synaptically released inhibitory neurotransmitter GABA. Yet, astrocyte-neuron communication in brain circuits and its behavioral outcome remained unknown. This study aimed at investigating whether astrocytes actively participate in information […]
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Grasping an object – model describes complete movement planning in the brain
Neuroscientists at the German Primate Center (DPZ) – Leibniz Institute for Primate Research in Göttingen have succeeded for the first time in developing a model that can seamlessly represent the entire planning of movement from seeing an object to grasping it. Comprehensive neural and motor data from grasping experiments with two rhesus monkeys provided decisive […]
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Radicals seem to be good for the brain
Reactive oxygen molecules, also known as “free radicals”, are generally considered harmful. However as it now turns out, they control cellular processes, which are important for the brain’s ability to adapt – at least in mice. The researchers focused on the “hippocampus”, a brain area that is regarded as the control center for learning and […]
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Baby’s first breath triggers life-saving changes in the brain
A team of researchers have discovered a signaling system within the brainstem that activates almost immediately at birth to support early breathing. That first gasp that every parent cherishes appears to trigger this support system. “Birth is traumatic for the newborn, as the baby has to independently take control over various important body functions, including […]
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Hidden network of enzymes accounts for loss of brain synapses in Alzheimer’s
A new study on Alzheimer’s disease by Scripps Research scientists has revealed a previously unknown biochemical cascade in the brain that leads to the destruction of synapses, the connections between nerve cells that are responsible for memory and cognition. The findings present a fresh angle for discovering drugs that treat Alzheimer’s disease, which affects roughly […]
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How the brain decides to make an effort
Neuroscientists have provided clear visual evidence that a region of the human brain known as the ventral striatum kicks in during decision-making to weigh the costs versus the benefits of making a physical effort. Nature Human Behavior published the research by scientists at Emory University. It gives the first detailed view of ventral striatum activity […]
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Potential Means of Improving Learning and Memory in People with Mental illnesses
Johns Hopkins Medicine researchers report they have identified a genetic variation in the brain tissue of a subset of deceased people — some with typical mental health and some with schizophrenia or other psychoses — that may influence cognition and IQ. In the process, they unearthed biochemical details about how the gene operates. Results of […]
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社交距离对大脑的影响
研究发现一种大脑分子，该分子可以充当动物环境中其他生物的“温度计”，斑马鱼通过机械感受和水流运动“感觉”其他人的存在，这一过程释放了脑内激素。 目前对于大脑系统是如何感知社会环境知之甚少，为了探究神经元基因是否对社会环境的急剧变化做出反应，研究员在不同的时期将斑马鱼单独或与其亲戚一起饲养，他们使用RNA测序来测量数千种神经元基因的表达水平。 结果发现在社交隔离环境中饲养的鱼类，其少数基因表达存在一致的变化，其中之一是甲状旁腺激素2（pth2），该基因编码大脑中一种相对未知的肽。pth2表达不仅追踪了其他人的存在，还追踪了他们的密度。令人意外的是，当斑马鱼被隔离时，pth2在大脑中消失了，但是当把其他鱼加到鱼缸后，其pth2的表达水平迅速升高，就像温度计读数一样。研究还证实了控制pth2表达的感觉方式不是视觉，味觉或嗅觉，而是机械感觉（受试鱼感受到其他鱼类的身体移动）。 该研究表明相对未开发的神经肽Pth2可能具有令人惊讶的作用，它可以追踪并响应动物社交环境的种群密度。很明显，其他动物的存在会对动物获得资源和最终生存产生重大影响-因此，这种神经激素很可能会调节社交大脑和行为网络。
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重度抑郁症或能由独特的肠道微生物组进行定义
据对311位个体所做的一项研究披露，科学家们发现，与健康对照组相比，有3种噬菌体、47种细菌和50种粪便代谢物在重度抑郁症（MDD）患者体内的丰度明显增多或减少。这些发现提供的证据表明，MDD或以肠道微生物组失调为特征。Y研究人员还根据他们发现的MDD的细菌、病毒和代谢特征推出了一组标记物指标，后者可有效地区分MDD患者和对照组。一种类似的基于生物标记物的诊断工具或可帮助医生更好地诊断MDD，从而为临床访谈提供指南，而这些访谈常会导致误诊。虽然先前的研究已经观察到MDD患者存在肠道微生物组紊乱，但研究人员尚未发现那些在这一常见精神疾病患者中有所不同的细菌种类，也未就肠道病毒是否也在MDD中失调进行研究。为更多地了解MDD如何特异性地影响肠道中细菌和病毒群落以及粪便代谢特征，分析了采自156名MDD患者和155名健康对照者的311个粪便样本中的基因物质，并对粪便代谢物进行了大规模的气相色谱-质谱分析。研究人员发现，与对照相比，MDD患者的细菌组成存在明显差异，观察到MDD患者的细菌组成中含有较多的属于拟杆菌属的细菌，而属于布劳特氏菌属和真细菌的细菌则减少。肠道微生物组中有更多的拟杆菌或能解释以前的观察结果，即MDD患者的细胞因子水平增加、炎症增加，而布劳特氏菌减少则会导致抗炎作用丧失。虽然研究人员在MDD和对照组间没有发现病毒组成存在明显差异，但他们确实发现，MDD患者体内有3种噬菌体的丰度下降。作者建议未来的研究应探索这些噬菌体的作用。
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强迫症和焦虑症共病的神经环路机制和潜在改善靶点
近日，南京大学生命科学学院、医药生物技术国家重点实验室和脑科学研究院朱景宁教授团队在强迫症和焦虑症共病的神经机制和潜在改善靶点的研究中取得重要进展。该课题组在其近年来对下丘脑调控基底神经节环路功能系列研究的基础上，新构建了HDC-Cre大鼠（HDC为体内催化组胺合成的关键酶），并发现选择性激活中枢组胺能神经系统的唯一起源下丘脑结节乳头体核（TMN）到伏隔核（NAc）核心部的组胺能直接神经投射能够通过作用于突触前H3受体，改善由急性束缚应激诱导的焦虑和强迫症样行为。NAc核心部中的组胺H3受体作为突触前异身受体发挥选择性抑制谷氨酸能而非GABA能突触传递的作用。尽管组胺H3受体在来自内侧前额叶皮层的前边缘皮层（PrL）、基底外侧杏仁核（BLA）和腹侧海马（vHipp）的谷氨酸能神经投射的轴突末梢均有表达，但光遗传学和化学遗传学选择性操控表明，只有PrL-NAc通路才是NAc核心部谷氨酸能神经传入中唯一同时介导焦虑和强迫症样行为的神经环路。抑制PrL-NAc谷氨酸能神经环路可预防急性束缚应激诱发的焦虑伴强迫症样行为，而组胺或H3受体选择性激动剂RAMH则可显著改善光激活PrL-NAc谷氨酸能神经环路诱导的焦虑伴强迫症样表型。 该研究成果揭示了一条介导强迫症和焦虑症共病的PrL-NAc谷氨酸能神经环路，而该环路受到组胺H3突触前异身受体的调控。这一成果将为临床认识强迫症和焦虑症共病发生发展的病理生理机制、深部脑刺激NAc治疗难治性强迫症和焦虑症的神经机制以及靶向突触前H3受体潜在治疗策略的研发提供了全新的视角。