Thalamocortical Dynamics and Consciousness

丘脑皮质动力学和意识

• 批准号: 10199752
• 负责人: EMERY N BROWN
• 金额: $ 39.34万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-08 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10199752
• 关键词: Affect; Anesthesia procedures; Anesthetics; Area; Attention; Auditory; Auditory area; Brain; Chronic; Communication; Conscious; Coupled; Coupling; Data; Deep Brain Stimulation; Electric Stimulation; Electrodes; Feedback; General Anesthesia; Link; Monkeys; Neurologist; Neurons; Neurosurgeon; Operative Surgical Procedures; Parietal Lobe; Pattern; Performance; Phase; Play; Prefrontal Cortex; Primates; Propofol; Purpura; Recovery; Rogaine; Role; Sedation procedure; Sensory; Short-Term Memory; Signal Transduction; Sleep; Stimulus; Structure; Testing; Thalamic Nuclei; Thalamic structure; Unconscious State; Wakefulness; awake; experience; frontal lobe; multimodality; neural correlate; response; somatosensory

Top-down functions (e.g., attention and working memory) go hand-in-hand with consciousness. Yet we know more about the former, because it is hard to define consciousness in most contexts. There is, however, a way in. General anesthesia (GA) provides transition through different stages of consciousness. We aim to determine which aspects of cortical processing are critical for these changes by using a surgical anesthetic, propofol, in monkeys. Propofol increases cortical-wide delta oscillations and alpha in frontal cortex. One hypothesis posits that the increased frontal alpha disrupts top-down cortical feedback from frontal cortex. Another points to the widespread delta oscillations that, unlike sleep, are decoupled across cortex. This could fragment long-range communication across cortex or, as some suggest, loss of consciousness (LOC) could be due to frontal-parietal cortex disconnectivity per se. The thalamus is likely to play a major role. Mounting evidence suggests it controls top-down cortical processing, perhaps by modulating cortical oscillations. Abnormal thalamic oscillations could entrain different cortical areas or the changed dynamics could be largely a cortical phenomenon. Previous primate studies of GA lack the combination of wide scope and single-neuron precision to directly test these hypotheses. We will use chronic intracranial multiple electrodes in monkeys to record simultaneously from a wide range of critical brain structures (prefrontal cortex, posterior parietal cortex, auditory cortex, and thalamus). We will also test if thalamic stimulation can restore consciousness and wakeful cortical dynamics.

自上而下的功能（例如，注意力和工作记忆）与意识密切相关。然而我们 我更了解前者，因为在大多数情况下很难定义意识。是的， 但是有办法进去全身麻醉（GA）提供了不同阶段的过渡， 意识我们的目标是确定皮层处理的哪些方面对这些变化至关重要 通过在猴子身上使用外科麻醉剂异丙酚。异丙酚增加皮层δ振荡 和额叶皮层的阿尔法。一种假设认为，额叶阿尔法的增加扰乱了自上而下的 额叶皮层的反馈另一种观点则指出，与 睡眠，在大脑皮层中是分离的。这可能会破坏大脑皮层之间的远程通讯， 有些人认为，意识丧失可能是由于额叶-顶叶皮层本身的断开。 丘脑可能起着重要作用。越来越多的证据表明，它控制着自上而下的大脑皮层 处理，也许通过调节皮质振荡。异常的丘脑振荡会导致 不同的皮层区域或改变的动力学可能主要是皮层现象。先前 遗传算法的灵长类研究缺乏广泛的范围和单神经元精度的组合，以直接测试 这些假设。我们将在猴子身上使用慢性颅内多电极来记录 同时从广泛的关键大脑结构（前额叶皮层，后顶叶皮层， 听觉皮层和丘脑）。我们还将测试丘脑刺激是否能恢复意识， 清醒的皮层动力学