CRCNS: Collaborative Research: The role of inhibition and correlated dynamics in cortical visual processing

大脑皮层由两种相互竞争的脑细胞组成：抑制性神经元倾向于抑制大脑活动，而兴奋性神经元则相反。这个项目将阐明控制抑制与激发平衡的原则。专注于抑制的作用，该项目将测试一种假设，即特定的中间水平的抑制对感觉信息处理是最佳的，因为它使皮层网络处于一种称为临界的特殊操作状态。当抑制过高时，皮质神经元受到抑制，并在很大程度上独立行动。当抑制作用过低时，神经元就会过度活跃，并在很大程度上一致行动。这两种极端都不利于有效的信息处理。然而，从高水平逐渐降低抑制可能导致神经元之间突然出现相关的、强烈的活动。这种开始的临界点被称为临界。重要的是，计算机模型和皮层切片研究预测，在关键时刻，某些类型的信息处理是优化的。然而，在一个完整的感觉系统中，临界性在处理真实感觉输入中的潜在关键作用仍未得到验证。这样的测试将在体外全脑准备中进行，使研究人员能够精确地控制全局抑制水平，用微电极阵列记录皮质活动数小时，并用自然图像刺激视网膜。采用新颖的、统计严谨的、多方面的、临界性的定量测试，提出的研究将确定在视觉加工过程中，抑制和临界性在完整皮层中的作用。具体来说，实验旨在确定从视觉刺激到皮层反应的信息传递是否在中间抑制水平（表现为临界性）下最大化。这个项目代表了真实感官处理中临界性的假设功能益处的第一个实验测试。它建立在一个强大的概念基础上，结合了统计物理学和计算神经科学，并可能为研究大型神经网络中的皮层视觉处理打开一个新的范例。这种新模式与新兴的新技术特别相关，这些新技术可以记录数千个神经元的活动。从医学角度来看，这一贡献是重要的，因为它有望阐明许多具有异常抑制的脑疾病的病因学。最后，该项目通过教师培训和课堂演示，将令人兴奋的研究带到密苏里州和阿肯色州的高中。新培养的对STEM研究的兴趣将通过纵向测量来评估。

The cerebral cortex is comprised of two competing types of brain cells: inhibitory neurons tend to suppress brain activity while excitatory neurons do the opposite. This project will illuminate principles governing the balance of inhibition versus excitation. Focusing on the role of inhibition, the project will test the hypothesis that a particular intermediate level of inhibition is optimal for sensory information processing, because it places the cortex network in a special operating regime called criticality. When inhibition is too high, cortical neurons are suppressed and act largely independently. When inhibition is too low neurons are hyperactive and act largely in unison. Neither extreme is conducive to effective information processing. However, gradually decreasing inhibition from a high level can result in an abrupt onset of correlated, intense activity among the neurons. The tipping point of this onset is called criticality. Importantly, computer models and cortex slice investigations predict that at criticality certain types of information processing are optimized. However, the potentially pivotal role of criticality in processing real sensory input in an intact sensory system remains untested. Such tests will be undertaken here in an in vitro whole-brain preparation that allows the researchers to precisely manipulate levels of global inhibition, record cortical activity with microelectrode arrays for many hours, and stimulate the retina with naturalistic images. Employing novel, statistically rigorous, multifaceted, quantitative tests of criticality, the proposed research will determine the roles of inhibition and criticality in intact cortex during visual processing. Specifically, the experiments are designed to determine whether information transfer from visual stimulus to cortical response is maximized at an intermediate level of inhibition which manifests as criticality.This project represents the first experimental test of the hypothesized functional benefits of criticality in real sensory processing. It builds on a strong conceptual foundation combining statistical physics and computational neuroscience, and may open a new paradigm for investigating cortical visual processing in large neural networks. This new paradigm is particularly relevant in light of emerging new technologies that enable the recording of activity from thousands of neurons. From the medical perspective this contribution is significant because it is expected to illuminate the etiology of numerous brain disorders with abnormal inhibition. Finally, the project brings the excitement of research into Missouri and Arkansas high schools with teacher training and classroom presentations. Newly fostered interest in STEM research will be assessed by longitudinal measures.