Non-invasive laminar electrophysiology in humans

人体非侵入性层状电生理学

• 批准号: BB/M009645/1
• 负责人: Gareth Barnes
• 金额: $ 44.08万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM009645%2F1
• 关键词: Non; invasive; laminar; electrophysiology; humans

Through experience we learn what to expect from the world around us. We become familiar with particular sensory information and we use this previous experience to make predictions about what we expect to see or touch. When the sensory information is not as we expected, this information (or prediction error) is fed forward to correct future predictions. For example it may be that you have had the impression that your stationary train is leaving the station simply because another train moves alongside you. This is an example of visual information making a prediction about the state of the world- which in this case happens to be a prediction error. We know from the anatomy of the cortex that the pathways that carry this feedback (predictions) and feedforward (prediction errors) information intertwine in parallel streams which interconnect brain regions that process very low level sensory information through multiple intermediate levels right up to those brain regions in which we make decisions about what to do. Interestingly, these pathways have distinct origins with feedforward and feedback pathways originating in the upper and lower cortical layers respectively (separated by around 3-4mm). Besides being distinguishable anatomically, these feedback and feedforward streams operate within distinct frequency ranges, the feedback signals changing more slowly (about 10-20 times a second) than the feedforward (about 30-60 times a second). At present the only way that we can look at these feedforward and feedback signals as they pass through the brain is through implanting micro-electrode arrays in the brains of animals. This is because the majority of human brain scanners either can see the layers but can only watch how they change over many seconds (functional Magnetic Resonance Imaging); or they distinguish the feedback and feedfoward signals in time but cannot resolve where they are coming from (electroencephalography or EEG). This grant builds on recent technological developments in magnetoencephalography (MEG) in which we measure magnetic fields outside the head produced by electrical currents flowing in the human brain. MEG, like EEG, can distinguish between these feedforward and feedback signals in time and frequency; importantly we have recently shown that it is also possible to distinguish between cortical layers using MEG. This is made possible because we have very precise models of where the different cortical layers lie with respect to our magnetic field measuring system (MEG). In this grant we put these two things together and expect to show that we can non-invasively disentangle feedback from feedforward information in both frequency (feedback low frequency, feedforward high frequency) and space (feedforward and feedback origins in upper and lower cortical layers respectively). This is a completely safe and non-invasive technique we can use in humans. Importantly, it will allow us to study how this feedforward and feedback information propagates across multiple areas of the human brain simultaneously - something that cannot even be done in invasive animal studies.This will not only help us understand how the brain works, but will help us understand what happens when these feedback and feedforward streams become compromised in conditions such as Parkinson's disease of schizophrenia.

通过经验，我们了解对周围世界的期望。我们逐渐熟悉特定的感官信息，并利用以前的经验来预测我们期望看到或触摸到的东西。当感觉信息不符合我们的预期时，该信息（或预测误差）将被前馈以纠正未来的预测。例如，您可能有这样的印象：您的静止火车即将离开车站，仅仅是因为另一列火车在您旁边行驶。这是视觉信息对世界状态进行预测的一个例子——在这种情况下，这恰好是一个预测错误。我们从皮层的解剖结构中知道，携带反馈（预测）和前馈（预测误差）信息的通路以并行的方式交织在一起，这些并行的流将处理非常低水平的感觉信息的大脑区域通过多个中间级别一直连接到我们做出做什么决定的大脑区域。有趣的是，这些通路具有不同的起源，前馈和反馈通路分别起源于上皮层和下皮层（间隔约 3-4mm）。除了在解剖学上可区分之外，这些反馈和前馈流在不同的频率范围内运行，反馈信号的变化（大约每秒 10-20 次）比前馈信号（大约每秒 30-60 次）变化得更慢。目前，我们观察这些前馈和反馈信号通过大脑时的唯一方法是在动物大脑中植入微电极阵列。这是因为大多数人脑扫描仪要么可以看到各层，但只能观察它们在几秒钟内的变化（功能性磁共振成像）；或者他们及时区分反馈和前馈信号，但无法确定它们来自何处（脑电图或脑电图）。这笔赠款建立在脑磁描记术（MEG）最新技术发展的基础上，在脑磁描记术中，我们测量人脑中流动的电流产生的头部外部磁场。 MEG和EEG一样，可以在时间和频率上区分这些前馈和反馈信号；重要的是，我们最近表明，也可以使用 MEG 来区分皮质层。这之所以成为可能，是因为我们拥有非常精确的模型，可以了解不同皮质层相对于我们的磁场测量系统 (MEG) 的位置。在这项资助中，我们将这两件事放在一起，并期望表明我们可以非侵入性地从频率（低频反馈、高频前馈）和空间（分别位于上皮层和下皮层的前馈和反馈起源）的前馈信息中分离出反馈。这是一种完全安全且非侵入性的技术，我们可以在人类身上使用。重要的是，它将使我们能够研究这种前馈和反馈信息如何同时在人脑的多个区域传播——这在侵入性动物研究中甚至无法完成。这不仅有助于我们了解大脑是如何工作的，而且有助于我们了解当这些反馈和前馈信息流在帕金森病或精神分裂症等疾病中受到损害时会发生什么。

项目成果

Using optically-pumped magnetometers to measure magnetoencephalographic signals in the human cerebellum

使用光泵磁力计测量人类小脑中的脑磁信号

• DOI: 10.1101/425447
• 发表时间: 2018
• 作者: Lin C

Estimates of cortical column orientation improve MEG source inversion.

• DOI: 10.1016/j.neuroimage.2020.116862
• 发表时间: 2020-08-01
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Bonaiuto JJ;Afdideh F;Ferez M;Wagstyl K;Mattout J;Bonnefond M;Barnes GR;Bestmann S
• 通讯作者: Bestmann S

Laminar dynamics of beta bursts in human motor cortex

人类运动皮层β爆发的层流动力学

• DOI: 10.1101/2021.02.16.431412
• 发表时间: 2021
• 作者: Bonaiuto J

A new generation of magnetoencephalography: Room temperature measurements using optically-pumped magnetometers.

• DOI: 10.1016/j.neuroimage.2017.01.034
• 发表时间: 2017-04-01
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Boto E;Meyer SS;Shah V;Alem O;Knappe S;Kruger P;Fromhold TM;Lim M;Glover PM;Morris PG;Bowtell R;Barnes GR;Brookes MJ
• 通讯作者: Brookes MJ

Non-invasive laminar inference with MEG: Comparison of methods and source inversion algorithms.

• DOI: 10.1016/j.neuroimage.2017.11.068
• 发表时间: 2018-02-15
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Bonaiuto JJ;Rossiter HE;Meyer SS;Adams N;Little S;Callaghan MF;Dick F;Bestmann S;Barnes GR
• 通讯作者: Barnes GR