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Central trafficking compartment in neurons malfunctions in majority of Alzheimer’s patients
A new study from Small’s laboratory found that, in many patients, tau secretion arises from tiny malfunctioning compartments inside the brain’s neurons, suggesting that these malfunctional compartments are commonly involved in the appearance of Alzheimer’s disease. These tiny compartments, called endosomes, function as a ‘grand central station’ and traffic proteins throughout a cell. The new […]
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科学家确定推动身体对恐惧,焦虑的反应的脑细胞
科学家研究了杏仁核中叫做BNST(终纹床核)的大脑区域,该区域在先前的研究中与小鼠的恐惧和焦虑行为相关。越来越多的科学家将这一区域视为未来精神药物的有希望的靶标。因此,科研人员将研究方向集中在一组表达神经递质基因Pnoc的BNST神经元,该基因与疼痛敏感性有关,最近又与动机有关。 该团队使用了一种相对较新的技术,称为双光子显微镜技术。当老鼠面对有害的或吸引人的气味时,直接对老鼠大脑中的BNST Pnoc神经元成像——这些气味分别可靠地引起恐惧/焦虑和奖励行为,以及适当的唤起反应。以此方式,科学家们发现,当给动物提供这些气味刺激中的任何一种时,这些神经元中的活性往往伴随着小鼠瞳孔的快速扩张。
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两阶段理论适用于阿尔茨海默氏症、帕金森氏症、肌肉萎缩等疾病
研究发现,在细胞水平上的变性发生在两个不同的阶段,其标志是调控基本细胞功能的蛋白质信号通路的活动非常不同。 研究人员称:“我们希望临床医生和其他研究人员明白,退化的两个阶段代表不同的实体,信号通路上的不同对疾病病理会有不一样的影响,换句话说,我们认为病人需要根据他们所处的阶段接受不同的治疗。” Stern和McNew的图表显示了关键细胞信号蛋白的活性在变性开始时是如何增加或减少的,最终导致氧化应激。然后,氧化应激导致了疾病的第二阶段,在此期间发生退化,其中牵涉到第一阶段的信号蛋白表现出完全不一样的行为方式。
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科学家发现阿尔茨海默氏痴呆症与Dlgap2基因的新联系
通过研究一大批不同基因的老鼠的记忆和脑组织,研究小组发现,Dlgap2基因的表达与老鼠的记忆丧失程度和人类患阿尔茨海默氏痴呆的风险有关,进一步的研究将确定该基因如何影响痴呆和精神功能。 Dlgap2位于神经元的突触中,用于固定学习和记忆所需要的神经元之间信号的关键受体。研究人员称,在研究人类死后的脑组织时,研究小组发现,在“认知健康状况较差”和“认知衰退较快”的人死前,Dlgap2水平较低。
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Brain waves guide us in spotlighting surprises
By measuring thousands of neurons along the surface, or cortex, of the brain in animals as they reacted to predictable and surprising images, the researchers observed that low frequency alpha and beta brain waves, or rhythms, originating in the brain’s frontal cognitive regions tamped down neural activity associated with predictable stimuli. That paved the way […]
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Pregnancy stress may shape baby brain
Infants’ brains may be shaped by levels of stress their mother experiences during pregnancy, a study has revealed. Stress levels in mothers – measured by a hormone linked to anxiety and other health problems – is related to changes in areas of the infant brain associated with emotional development, the study suggests. Doctors say the […]
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Team uses copper to image Alzheimer’s aggregates in the brain
A proof-of-concept study conducted in a mouse model of Alzheimer’s disease offers new evidence that copper isotopes can be used to detect the amyloid-beta protein deposits that form in the brains of people living with – or at risk of developing – Alzheimer’s.
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Stronger memories can help us make sense of future changes
New research found the stronger a memory is first encoded, the easier it is for a person to notice subsequent changes and to integrate them into their updated understanding. “The bigger the discrepancy is between a previous memory and what happens the next time,” Zacks said, “the stronger the signal is that you need to […]
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Scientists Identify Brain Cells that Help Drive Bodily Reaction to Fear, Anxiety
Rodríguez-Romaguera, Ung, Stuber and colleagues examined a brain region within the amygdala called the BNST (bed nucleus of the stria terminalis), which has been linked in prior research to fear and anxiety-like behaviors in mice. Increasingly, scientists view this region as a promising target for future psychiatric drugs. In this case, the researchers zeroed in […]
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Two-phase theory applies to diseases like Alzheimer’s, Parkinson’s, muscle atrophy
Researchers in Rice’s Department of BioSciences, propose that degeneration, at the cellular level, occurs in two distinct phases that are marked by very different activities of protein signaling pathways that regulate basic cell functions. “We would like clinicians and other researchers to understand that the two phases of degeneration represent distinct entities, with distinct alterations […]