Cortical Processing of visual information during alert and non-alert brain state

描述（由申请人提供）：本提案旨在了解当受试者在清醒和非清醒状态之间转换时视觉处理发生的变化。由于控制眼睛位置的行为方法的发展，在理解警觉、注意力集中的受试者的视觉感知的中心机制方面取得了很大进展。然而，对于大脑皮层在警觉性减弱时所起的作用却知之甚少。清醒、非警觉状态不等同于麻醉，也不等同于睡眠状态。当我们不警觉时，我们能够感知，但我们的感知能力不同。人们普遍认为，当我们不警觉时，“事故就会发生”，但早期丘脑或视觉皮层机制在多大程度上可能对此负责（与高级认知过程相反），这是一个未决的问题。这个建议依赖于一个非常适合解决这个问题的独特模型系统：清醒的兔子，这种动物的“内在精神生活”在警觉和非警觉状态之间透明地转换，其稳定的眼睛和羞怯的天性使其成为这些实验的理想对象。拟议的研究将检查清醒受试者的大脑状态的变化如何影响在视觉丘脑皮质和皮质内网络中发生的多个连续的信息处理阶段。实验将测量皮层输入和输出层的兴奋性和抑制性神经元的视觉反应特性的状态依赖变化，并将进行研究

DESCRIPTION (provided by applicant): This proposal aims to understand the changes in visual processing that occur when subjects shift between alert and non-alert waking states. Thanks to the development of behavioral methods for the control of eye position, great advances have been made in understanding central mechanisms of visual perception of alert, attentive subjects. However, there is little understanding of cortical processes that come into play when alertness wanes. The awake, non-alert state is not equivalent to anesthesia, or to sleep states. When non-alert, we are capable of perception, but our perceptual capacities differ. It is commonly believed that "accidents happen" when we are not alert, but the extent to which early thalamic or visual cortical mechanisms may be responsible for this (as opposed to higher cognitive processes) is an open question. This proposal relies on a unique model system that is very well-suited to address this question: the awake rabbit, an animal whose "inner mental life" transparently shifts between alert and non- alert states, and whose stable eyes and diffident nature make it an ideal subject for these experiments. The proposed research will examine how changes in the brain state of awake subjects influence the multiple, sequential stages of information processing that occur within the visual thalamocortical and intracortical network. The experiments will measure state- dependent changes in the visual response properties of excitatory and inhibitory neurons at the input and output layers of the cortex and will investigate the underlying mechanisms leading to these changes, at the subthreshold and spiking level. This work will lead to a better understanding of cortical mechanisms of visual processing in a dynamic, awake brain. From a health perspective, these studies will have an important impact on our understanding of how alertness/vigilance deficits can impact visual perception and performance, and will provide the basis for future clinical studies of human mental health and behavioral disorders. PUBLIC HEALTH RELEVANCE: The current work will have an important impact on our understanding of how alertness/vigilance deficits can impact visual perception and performance. A disruption in response gain within thalamocortical systems has been associated with mental diseases that involve changes in sensory processing and the level of vigilance. This proposal will reveal the mechanisms that modulate response gain within the visual thalamocortical system and, by doing so, it will provide the basis for future clinical studies of human mental health and behavioral disorders.