Neuronal networks

神经元网络
  • 文章类型: Journal Article
    生物神经网络以其以极低功耗处理信息的能力而闻名。人工智能等领域,计算成本很高,正在寻找生物系统中启发的替代品。一个鼓舞人心的替代方案是实现硬件架构,复制生物神经元的行为,但具有电子设备编程能力的灵活性,所有这些都与相对较低的运营成本相结合。为了在这个探索中前进,在这里,我们分析HEENS硬件架构以类似于在实验室中生长的体外神经元网络的方式运行的能力。为此,我们考虑了大约400个神经元的活神经元培养物中的自发活动数据,并将它们的集体动力学和功能行为与从直接数值模拟(计算机模拟)和硬件实现(硬石灰岩)获得的数据进行了比较。结果表明,HEENS能够以高效成本比模拟体外和计算机模拟系统,以及不同的网络拓扑设计。我们的工作表明,紧凑的低成本硬件实现是可行的,为未来开辟新的道路,高效的神经形态设备和先进的人机接口。
    Biological neural networks are well known for their capacity to process information with extremely low power consumption. Fields such as Artificial Intelligence, with high computational costs, are seeking for alternatives inspired in biological systems. An inspiring alternative is to implement hardware architectures that replicate the behavior of biological neurons but with the flexibility in programming capabilities of an electronic device, all combined with a relatively low operational cost. To advance in this quest, here we analyze the capacity of the HEENS hardware architecture to operate in a similar manner as an in vitro neuronal network grown in the laboratory. For that, we considered data of spontaneous activity in living neuronal cultures of about 400 neurons and compared their collective dynamics and functional behavior with those obtained from direct numerical simulations (in silico) and hardware implementations (in duris silico). The results show that HEENS is capable to mimic both the in vitro and in silico systems with high efficient-cost ratio, and on different network topological designs. Our work shows that compact low-cost hardware implementations are feasible, opening new avenues for future, highly efficient neuromorphic devices and advanced human-machine interfacing.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: English Abstract
    Cannabis use and cannabis use disorders have taken on a new social significance as a result of partial legalization. In 2021 a total of 4.5 million adults (8.8%) in Germany used the drug. The number of users as well as problematic use have risen in the last decade. Cannabis products with a high delta-9-tetrahydrocannabinol (THC) content and their regular use lead to changes in cannabinoid receptor distribution in the brain and to modifications in the structure and functionality of relevant neuronal networks. The consequences of cannabinoid use are particularly in the psychological functioning and can include intoxication, harmful use, dependence with withdrawal symptoms and cannabis-induced mental disorders. Changes in the diagnostics between ICD-10 and ICD-11 are presented. Interdisciplinary S3 guidelines on cannabis-related disorders are currently being developed and will be finalized shortly.
    UNASSIGNED: Cannabiskonsum und Cannabiskonsumstörungen haben durch die Teillegalisierung eine neue gesellschaftliche Brisanz erreicht. Im Jahr 2021 nutzten 4,5 Mio. Erwachsene (8,8 %) in Deutschland die Droge. Die Zahl der Konsumenten und Konsumentinnen wie auch des problematischen Konsums ist angestiegen. Cannabisprodukte mit hohem δ‑9-Tetrahydrocannabinol(THC)-Gehalt sowie deren regelmäßiger Konsum führen zu Änderungen der Cannabinoidrezeptorverteilung im Gehirn und zu Modifikationen der Struktur und Funktionsfähigkeit relevanter neuronaler Netzwerke. Folgen des Konsums von Cannabinoiden liegen vor allem im psychischen Bereich und können Intoxikationen, schädlicher Gebrauch, Abhängigkeit mit Entzugssymptomen und cannabisinduzierte psychische Störungen sein. Änderungen der Diagnostik zwischen International Statistical Classification of Diseases and Related Health Problems 10 (ICD-10) und ICD-11 werden dargestellt. Eine interdisziplinäre S3-Leitinie „Cannabisbezogene Störungen“ wird aktuell entwickelt und in Kürze fertiggestellt.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    Gi偶联受体,特别是大麻素受体(CBRs),被认为是治疗脑部病变的透视目标,包括癫痫。然而,CBR激动剂抗惊厥作用的确切机制尚不清楚.我们已经发现,WIN55,212-2(CBR激动剂)抑制了双微胶或NH4Cl在大鼠海马神经元-神经胶质培养物的神经元中诱导的Ca2离子细胞内浓度的同步振荡(癫痫样活性)。正如我们所证明的,WIN55,212-2效应由CB1R受体介导。激动剂抑制电压门控钙通道介导的Ca2+流入,但不改变NMDA介导的流入,AMPA,和红藻氨酸受体。我们还发现磷脂酶C(PLC),蛋白激酶C(PKC),和G蛋白偶联的向内整流K通道(GIRK通道)参与了CB1R激活对癫痫样活性的抑制作用的分子机制。因此,我们的结果表明,CB1R激动剂的抗癫痫作用是由不同的细胞内信号级联介导的,包括非规范PLC/PKC相关途径。
    Gi-coupled receptors, particularly cannabinoid receptors (CBRs), are considered perspective targets for treating brain pathologies, including epilepsy. However, the precise mechanism of the anticonvulsant effect of the CBR agonists remains unknown. We have found that WIN 55,212-2 (a CBR agonist) suppresses the synchronous oscillations of the intracellular concentration of Ca2+ ions (epileptiform activity) induced in the neurons of rat hippocampal neuron-glial cultures by bicuculline or NH4Cl. As we have demonstrated, the WIN 55,212-2 effect is mediated by CB1R receptors. The agonist suppresses Ca2+ inflow mediated by the voltage-gated calcium channels but does not alter the inflow mediated by NMDA, AMPA, and kainate receptors. We have also found that phospholipase C (PLC), protein kinase C (PKC), and G-protein-coupled inwardly rectifying K+ channels (GIRK channels) are involved in the molecular mechanism underlying the inhibitory action of CB1R activation against epileptiform activity. Thus, our results demonstrate that the antiepileptic action of CB1R agonists is mediated by different intracellular signaling cascades, including non-canonical PLC/PKC-associated pathways.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    大脑电路的生物详细模型是具有挑战性的建立和模拟由于大量的神经元,它们复杂的相互作用,和许多未知的生理参数。简化的数学模型更易于处理,但是当远离神经解剖学/生理学时,很难评估。我们提出了一个多尺度模型,粗粒度(CG),同时保留局部生物细节,在生物现实主义和可计算性之间提供了最好的平衡。本文提出了这样一个模型。一般来说,CG模型专注于神经元组之间的相互作用,这里称为“像素”,而不是单个细胞。在我们的案例中,动态在像素内和像素间尺度上交替更新,一个人通知另一个人,直到在两个尺度上都达到平衡。一个创新是我们如何利用潜在的生物学:利用大脑皮层局部解剖结构的相似性,我们将像素内动力学建模为由“外部”输入驱动的单个动力学系统。这些输入随像素外部的事件而变化,但它们的范围可以先验估计。与直接多尺度模拟相比,预先计算和制表所有潜在的局部响应显着加快了更新过程。我们使用灵长类视觉皮层模型来说明我们的方法。除了局部神经元到神经元的可变性(在任何CG近似中都必须丢失)之外,我们的模型以很小的计算成本再现了大规模网络模型的各种特征。这些包括神经元反应作为其取向选择性的结果,视觉神经元的主要功能。
    Biologically detailed models of brain circuitry are challenging to build and simulate due to the large number of neurons, their complex interactions, and the many unknown physiological parameters. Simplified mathematical models are more tractable, but harder to evaluate when too far removed from neuroanatomy/physiology. We propose that a multiscale model, coarse-grained (CG) while preserving local biological details, offers the best balance between biological realism and computability. This paper presents such a model. Generally, CG models focus on the interaction between groups of neurons-here termed \"pixels\"-rather than individual cells. In our case, dynamics are alternately updated at intra- and interpixel scales, with one informing the other, until convergence to equilibrium is achieved on both scales. An innovation is how we exploit the underlying biology: Taking advantage of the similarity in local anatomical structures across large regions of the cortex, we model intrapixel dynamics as a single dynamical system driven by \"external\" inputs. These inputs vary with events external to the pixel, but their ranges can be estimated a priori. Precomputing and tabulating all potential local responses speed up the updating procedure significantly compared to direct multiscale simulation. We illustrate our methodology using a model of the primate visual cortex. Except for local neuron-to-neuron variability (necessarily lost in any CG approximation) our model reproduces various features of large-scale network models at a tiny fraction of the computational cost. These include neuronal responses as a consequence of their orientation selectivity, a primary function of visual neurons.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    肾积水对肾绞痛的诊断至关重要。我们从超声图像中自动检测肾积水,以规范治疗并减少肾绞痛的误诊。
    匿名收集人体肾脏的超声图像,正常和肾积水,对神经网络进行了预处理。对六个“最先进的”模型进行了训练和交叉验证,用于检测肾积水,两个卷积网络用于肾脏分割。在测试阶段,性能指标包括真阳性,真正的底片,假阳性,假阴性,准确度,和F1得分,虽然分割任务的评估涉及准确性,精度,骰子,Jaccard,召回,ASSD。
    从三种不同的超声设备收集了总共523张超声肾脏图像(423张非肾积水和100张非肾积水)。在这个数据集上训练后,所有模型均用于评估200例新的超声肾脏图像(142例非肾积水肾脏和58例肾积水肾脏).AlexNet模型(GoogLeNet97%,AlexNet_v296%,ResNet5096%,ResNet10197.5%,和ResNet15295%)。deeplabv3_resnet50和deeplabv3_resnet101的骰子系数分别为94.74%和94.48%,分别,关于自动肾脏分割的任务。这项研究仅限于分析肾积水,但是这种特定的焦点能够实现高检测精度。
    我们表明,我们的自动超声深度学习模型可以进行训练,并用于以高精度解释和分割来自不同来源的超声图像。该方法将作为未来急性肾衰竭诊断算法的自动化工具。
    肾积水对诊断肾绞痛至关重要。人工智能的最新进展允许高精度地自动检测超声图像中的肾积水。这些方法将有助于规范诊断和治疗肾绞痛。
    UNASSIGNED: Hydronephrosis is essential in the diagnosis of renal colic. We automated the detection of hydronephrosis from ultrasound images to standardize the therapy and reduce the misdiagnosis of renal colic.
    UNASSIGNED: Anonymously collected ultrasound images of human kidneys, both normal and hydronephrotic, were preprocessed for neural networks. Six \"state of the art\" models were trained and cross-validated for the detection of hydronephrosis, and two convolutional networks were used for kidney segmentation. In the testing phase, performance metrics included true positives, true negatives, false positives, false negatives, accuracy, and F1 score, while the evaluation of the segmentation task involved accuracy, precision, dice, jaccard, recall, and ASSD.
    UNASSIGNED: A total of 523 sonographic kidney images (423 nonhydronephrotic and 100 hydronephrotic) were collected from three different ultrasound devices. After training on this dataset, all models were used to evaluate 200 new ultrasound kidney images (142 nonhydronephrotic and 58 hydronephrotic kidneys). The highest validation accuracy (98.5%) was achieved by the AlexNet model (GoogLeNet 97%, AlexNet_v2 96%, ResNet50 96%, ResNet101 97.5%, and ResNet152 95%). The deeplabv3_resnet50 and deeplabv3_resnet101 reached a dice coefficient of 94.74% and 94.48%, respectively, on the task of automated kidney segmentation. The study is limited by analyzing only hydronephrosis, but this specific focus enabled high detection accuracy.
    UNASSIGNED: We show that our automated ultrasound deep learning model can be trained and used to interpret and segmentate ultrasound images from different sources with high accuracy. This method will serve as an automated tool in the diagnostic algorithm of acute renal failure in the future.
    UNASSIGNED: Hydronephrosis is crucial in the diagnosis of renal colic. Recent advances in artificial intelligence allow automated detection of hydronephrosis in ultrasound images with high accuracy. These methods will help standardize the diagnosis and treatment renal colic.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    本文回顾了Luria的大脑三个功能单元模型。为了实现这一目标,综述了几个问题:功能系统理论以及系统发育和胚胎发育对脑功能组织的贡献。这篇评论揭示了几个事实。首先,基本稳态需求与复杂行为形式的关系/整合。其次,大脑的多尺度分层和分布式组织以及细胞和系统之间的相互作用。第三,Exaptation的系统发育作用,尤其是基底神经节和小脑扩张。最后,大脑的三方胚胎发生组织:Rhinic,边缘/副边缘,和超边缘区。显然,这些大脑组织原理与建立独立的大脑功能单元的尝试相矛盾。拟议的新模型由两个大型综合复合物组成:原始边缘复合物(Luria的I单元)和端脑皮层复合物(Luria的II和III单元)。因此,划分了五个功能单元:第一单元。原始或优先(脑干),为了维持生命,行为调制,和唤醒调节;第二单元。边缘系统和副边缘系统,对于情绪和享乐评估(危险和相关性检测以及对奖励/动机处理的贡献)和认知图的创建(上下文记忆,导航,和生成性[想象力]);第三单元。端脑皮质,用于感觉运动和认知处理(gnosis,实践,语言,计算,等。),语义和情景(上下文)记忆处理,和多式联运意识机构;第四单元。基底神经节系统,用于行为选择和强化(奖励导向行为);第五单元小脑系统,用于预测/预测(正交监督)行动的结果。提出的大脑单元只不过是大脑同时和分布式生理过程中的抽象。由于功能超越了解剖学,该模型必然涉及结构之间的过渡和重叠。除了经典的方法,这篇综述包括关于功能性大脑组织的最新系统观点的信息。讨论了本文的局限性。
    This paper reviews Luria\'s model of the three functional units of the brain. To meet this objective, several issues were reviewed: the theory of functional systems and the contributions of phylogenesis and embryogenesis to the brain\'s functional organization. This review revealed several facts. In the first place, the relationship/integration of basic homeostatic needs with complex forms of behavior. Secondly, the multi-scale hierarchical and distributed organization of the brain and interactions between cells and systems. Thirdly, the phylogenetic role of exaptation, especially in basal ganglia and cerebellum expansion. Finally, the tripartite embryogenetic organization of the brain: rhinic, limbic/paralimbic, and supralimbic zones. Obviously, these principles of brain organization are in contradiction with attempts to establish separate functional brain units. The proposed new model is made up of two large integrated complexes: a primordial-limbic complex (Luria\'s Unit I) and a telencephalic-cortical complex (Luria\'s Units II and III). As a result, five functional units were delineated: Unit I. Primordial or preferential (brainstem), for life-support, behavioral modulation, and waking regulation; Unit II. Limbic and paralimbic systems, for emotions and hedonic evaluation (danger and relevance detection and contribution to reward/motivational processing) and the creation of cognitive maps (contextual memory, navigation, and generativity [imagination]); Unit III. Telencephalic-cortical, for sensorimotor and cognitive processing (gnosis, praxis, language, calculation, etc.), semantic and episodic (contextual) memory processing, and multimodal conscious agency; Unit IV. Basal ganglia systems, for behavior selection and reinforcement (reward-oriented behavior); Unit V. Cerebellar systems, for the prediction/anticipation (orthometric supervision) of the outcome of an action. The proposed brain units are nothing more than abstractions within the brain\'s simultaneous and distributed physiological processes. As function transcends anatomy, the model necessarily involves transition and overlap between structures. Beyond the classic approaches, this review includes information on recent systemic perspectives on functional brain organization. The limitations of this review are discussed.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在理解协调身体和大脑的神经元网络的组织方面取得的重大进展中,它们的复杂性越来越重要,这是由于大量的成分之间的相互作用而产生的,这些成分具有强烈的层次结构,同时与“自我出现”。这种意识促使我们确定最好地量化伴随大脑持续进化动力学的“复杂性”的措施。在这一章中,在介绍性部分之后(第15.1),我们研究了Higuchi分形维数如何能够感知生理过程(15.2),神经(15.3)和精神(15.4)疾病,和神经调节效应(15.5),除了脑电图之外,还提到了其他测量神经元电活动的方法,例如脑磁图和功能磁共振。意识到由于与环境的持续相互作用,进一步的进步将支持对神经元活动的时间过程的更深入理解,我们得出的结论是,分形维数已经开始揭示大脑活动及其改变的生理学的重要特征。
    Among the significant advances in the understanding of the organization of the neuronal networks that coordinate the body and brain, their complex nature is increasingly important, resulting from the interaction between the very large number of constituents strongly organized hierarchically and at the same time with \"self-emerging.\" This awareness drives us to identify the measures that best quantify the \"complexity\" that accompanies the continuous evolutionary dynamics of the brain. In this chapter, after an introductory section (Sect. 15.1), we examine how the Higuchi fractal dimension is able to perceive physiological processes (15.2), neurological (15.3) and psychiatric (15.4) disorders, and neuromodulation effects (15.5), giving a mention of other methods of measuring neuronal electrical activity in addition to electroencephalography, such as magnetoencephalography and functional magnetic resonance. Conscious that further progress will support a deeper understanding of the temporal course of neuronal activity because of continuous interaction with the environment, we conclude confident that the fractal dimension has begun to uncover important features of the physiology of brain activity and its alterations.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在过去的几十年中,将分形几何引入神经科学一直是一个重大的范式转变,因为它有助于克服使用欧几里得和还原论方法分析神经元或整个大脑时出现的近似和限制。分形几何可以定量分析和描述大脑的几何复杂性,从它的单个单元到神经元网络。如本书第二部分所述,分形分析为研究脑细胞形态提供了定量工具(即,神经元和小胶质细胞)及其组分(例如,树突树,突触),以及大脑结构本身(皮层,功能模块,神经元网络)。自相似逻辑,它产生和塑造了大脑的不同分层系统,甚至是与它的“容器”相关的一些结构,“也就是说,颅骨上的颅骨缝线,在下面的章节中被广泛讨论,与分形分析的应用之间的联系神经解剖学和基础神经科学的临床应用在第三部分讨论。
    The introduction of fractal geometry to the neurosciences has been a major paradigm shift over the last decades as it has helped overcome approximations and limitations that occur when Euclidean and reductionist approaches are used to analyze neurons or the entire brain. Fractal geometry allows for quantitative analysis and description of the geometric complexity of the brain, from its single units to the neuronal networks.As illustrated in the second section of this book, fractal analysis provides a quantitative tool for the study of the morphology of brain cells (i.e., neurons and microglia) and its components (e.g., dendritic trees, synapses), as well as the brain structure itself (cortex, functional modules, neuronal networks). The self-similar logic which generates and shapes the different hierarchical systems of the brain and even some structures related to its \"container,\" that is, the cranial sutures on the skull, is widely discussed in the following chapters, with a link between the applications of fractal analysis to the neuroanatomy and basic neurosciences to the clinical applications discussed in the third section.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    神经元建立了大量的间隙连接耦合网络(GJ-nets),可以渗透离子或小分子,启用横向信号。在这里,我们研究了(1)致盲疾病对小鼠视网膜GJ-nets的影响和(2)电刺激对GJ通透性的影响。使用GJ示踪神经生物素在盲视网膜变性1(rd1)小鼠的急性视网膜外植体中追踪GJ通透性。通过边缘切割方法将示踪剂引入GJ网,其扩散在组织学制剂(荧光标记)中使用显微镜观察。使用单个大电极施加持续刺激以调节GJ渗透性。我们的发现是:(1)盲rd1视网膜通过开放GJ显示出广泛的细胞间偶联。确定了三个GJ网:水平,无碱,和神经节细胞网络。(2)持续刺激显著减少了示踪剂在所有细胞层中通过GJs的传播,与用甘泊酮进行药物抑制一样。我们得出的结论是,在致盲疾病后,rd1视网膜的GJ-nets仍保持偶联和功能,并且其渗透性可通过持续刺激进行调节。这些发现对于理解通过耦合网络和使用电植入物的治疗方法在疾病中的分子信号传导至关重要。例如引起视觉感觉或抑制皮质癫痫发作。
    Neurons build vast gap junction-coupled networks (GJ-nets) that are permeable to ions or small molecules, enabling lateral signaling. Herein, we investigate (1) the effect of blinding diseases on GJ-nets in mouse retinas and (2) the impact of electrical stimulation on GJ permeability. GJ permeability was traced in the acute retinal explants of blind retinal degeneration 1 (rd1) mice using the GJ tracer neurobiotin. The tracer was introduced via the edge cut method into the GJ-net, and its spread was visualized in histological preparations (fluorescent tagged) using microscopy. Sustained stimulation was applied to modulate GJ permeability using a single large electrode. Our findings are: (1) The blind rd1 retinas displayed extensive intercellular coupling via open GJs. Three GJ-nets were identified: horizontal, amacrine, and ganglion cell networks. (2) Sustained stimulation significantly diminished the tracer spread through the GJs in all the cell layers, as occurs with pharmaceutical inhibition with carbenoxolone. We concluded that the GJ-nets of rd1 retinas remain coupled and functional after blinding disease and that their permeability is regulatable by sustained stimulation. These findings are essential for understanding molecular signaling in diseases over coupled networks and therapeutic approaches using electrical implants, such as eliciting visual sensations or suppressing cortical seizures.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    记忆是指生活经验在大脑中积累的印记,代表人类从事思维、想象等高级心理活动的基础。以前,专注于记忆的研究活动总是针对神经元。然而,除了神经元,星形胶质细胞也参与编码,合并,和记忆的灭绝。特别是,已知星形胶质细胞在局部突触和大脑网络水平上影响神经元的募集和功能。此外,星形胶质细胞参与记忆和记忆相关疾病,特别是在阿尔茨海默病(AD)和创伤后应激障碍(PTSD),已被广泛调查。在这次审查中,我们描述了星形胶质细胞对突触可塑性和神经网络的独特贡献,并讨论了星形胶质细胞在不同类型的记忆处理中的作用。此外,我们还探讨了星形胶质细胞在记忆相关疾病发病机制中的作用,比如AD,大脑老化,创伤后应激障碍和成瘾,因此提示靶向星形胶质细胞可能是治疗记忆相关神经系统疾病的潜在策略.总之,本文强调,从星形胶质细胞的角度思考将为记忆相关神经系统疾病的诊断和治疗提供新的思路。
    Memory refers to the imprint accumulated in the brain by life experiences and represents the basis for humans to engage in advanced psychological activities such as thinking and imagination. Previously, research activities focused on memory have always targeted neurons. However, in addition to neurons, astrocytes are also involved in the encoding, consolidation, and extinction of memory. In particular, astrocytes are known to affect the recruitment and function of neurons at the level of local synapses and brain networks. Moreover, the involvement of astrocytes in memory and memory-related disorders, especially in Alzheimer\'s disease (AD) and post-traumatic stress disorder (PTSD), has been investigated extensively. In this review, we describe the unique contributions of astrocytes to synaptic plasticity and neuronal networks and discuss the role of astrocytes in different types of memory processing. In addition, we also explore the roles of astrocytes in the pathogenesis of memory-related disorders, such as AD, brain aging, PTSD and addiction, thus suggesting that targeting astrocytes may represent a potential strategy to treat memory-related neurological diseases. In conclusion, this review emphasizes that thinking from the perspective of astrocytes will provide new ideas for the diagnosis and therapy of memory-related neurological disorders.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

公众号