Lamina-specific cortical dynamics in human visual and sensorimotor cortices.
Lamina-specific cortical dynamics in human visual and sensorimotor cortices.
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DOI：
10.7554/elife.33977
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发表时间：
2018-10-22
期刊：
影响因子：
7.7
通讯作者：
Bestmann S
中科院分区：
文献类型：
--
作者：
Bonaiuto JJ;Meyer SS;Little S;Rossiter H;Callaghan MF;Dick F;Barnes GR;Bestmann S
不同的解剖和光谱通道被认为在皮层网络内的通信中起着特殊的作用。虽然α和β频率范围（7 - 40 Hz）的活动被认为主要来自传递反馈相关信息的核内皮质层，但在传递前馈信号的核上层中，伽马范围（bb0 - 40 Hz）的活动占主导地位。我们利用高精度的脑磁图来测试这个建议，直接和非侵入性的，在人类参与者执行视觉提示的动作。我们发现视觉α映射到皮层深层，而视觉γ主要发生在更浅层。这种层特异性在运动相关的感觉运动β和γ活动中得到了回应。这些层特异性的运动前后感觉运动β和γ活动的变化表明，感觉皮层的反馈和前馈通信具有更复杂的功能作用。因此，不同的频率通道以特定的方式在皮层中运作，但可能在感觉和运动过程中发挥不同的功能作用。当我们与周围的世界互动时，信号从一个神经元传递到另一个神经元，从一个大脑区域传递到另一个大脑区域。例如，当我们看一个物体时，信号会沿着大脑最外层的区域传递，这个区域被称为皮层。这条视觉通路上的每一个区域都比前一个区域进行更复杂的处理。但信息也会沿着这类皮质通路以相反的方向流动。这些反馈信号使通路上更远的区域能够影响它们前面的区域的活动。对动物的研究表明，就像高速公路一样，信息在皮层内沿着不同的车道以相反的方向传播。在哺乳动物中，这些通道由不同的细胞层组成。在猴子的视觉皮层中，反馈信号通过更深层的皮层传递，而前馈信号通过上层皮层传递。上层大脑活动的频率也高于下层。但我们自己的大脑也是如此吗？Bonaiuto等人使用一种叫做MEG的技术来测量健康志愿者大脑皮层上层和下层的大脑活动频率。志愿者们必须看屏幕上的图像，然后按下按钮做出反应。Bonaiuto等人观察到，深层皮层的活动大多发生在较低的频率，而上层皮层的活动大多发生在较高的频率。在视觉皮层和帮助计划和执行动作的皮层区域都发现了这种模式，与猴子的模式相匹配。在视觉皮层，上层的活动似乎携带着前馈信号。但在运动相关区域，反馈和前馈信号与皮质层的关系不太清楚。这些发现为目前有关大脑皮层组织的理论提供了支持。他们还表明，脑磁图可以在高空间分辨率下揭示快速变化的大脑活动。这些发现也可能为大脑疾病“示波器病”的起源提供线索。这些包括大脑活动特定频率的变化，包括精神分裂症和癫痫等。
Distinct anatomical and spectral channels are thought to play specialized roles in the communication within cortical networks. While activity in the alpha and beta frequency range (7 – 40 Hz) is thought to predominantly originate from infragranular cortical layers conveying feedback-related information, activity in the gamma range (>40 Hz) dominates in supragranular layers communicating feedforward signals. We leveraged high precision MEG to test this proposal, directly and non-invasively, in human participants performing visually cued actions. We found that visual alpha mapped onto deep cortical laminae, whereas visual gamma predominantly occurred more superficially. This lamina-specificity was echoed in movement-related sensorimotor beta and gamma activity. These lamina-specific pre- and post- movement changes in sensorimotor beta and gamma activity suggest a more complex functional role than the proposed feedback and feedforward communication in sensory cortex. Distinct frequency channels thus operate in a lamina-specific manner across cortex, but may fulfill distinct functional roles in sensory and motor processes. As we interact with the world around us, signals flow from neuron to neuron and from one brain area to the next. When we look at an object, for example, signals pass along a pathway of areas in the outermost part of the brain, called the cortex. Each area along this visual pathway performs more complex processing than the one before it. But information also flows in the opposite direction along such cortical pathways. These feedback signals enable areas further along the pathway to influence the activity of those before them. Studies in animals suggest that much like a highway, information is travelling in opposite directions within the cortex along different lanes. In mammals, these lanes consist of distinct layers of cells. In the visual cortex of monkeys, feedback signals travel via deeper layers of cortex, whereas feedforward signals travel via the upper layers. Brain activity in the upper layers also has a higher frequency than that in the lower layers. But is this also the case in our own brains? Bonaiuto et al. used a technique called MEG to measure the frequency of brain activity within the upper and lower layers of cortex in healthy volunteers. The volunteers had to look at images on a screen and then respond by pressing a button. Bonaiuto et al. observed that activity in deeper layers of cortex occurred mostly at lower frequencies, while activity in upper layers mostly happened at higher frequencies. This pattern, which matches that seen in monkeys, was found in both visual cortex and in areas of cortex that help plan and execute movements. In visual cortex, the activity in the upper layers appeared to carry feedforward signals. But in movement-related areas, feedback and feedforward signals were less clearly related to cortical layers. These findings lend support to current theories about how the cortex is organized. They also show that MEG can reveal rapidly changing brain activity at a high spatial resolution. The findings may also provide clues to the origins of brain disorders called oscillopathies. These involve changes in specific frequencies of brain activity, and include schizophrenia and epilepsy, among others.