Anticipatory Hemodynamic Signals in Primary Visual Cortex

初级视觉皮层的预期血流动力学信号

• 批准号: 8264772
• 负责人: ANIRUDDHA DAS
• 金额: $ 38.64万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8264772
• 关键词: Affect; Animal Model; Animals; Arousal; Attention; Attention Deficit Disorder; Auditory; Behavior; Blood; Blood Volume; Brain; Clinical; Complex; Detection; Discrimination; Disease; Electrodes; Electrophysiology (science); Event; Functional Magnetic Resonance Imaging; Goals; Hand; Hemoglobin; Human; Image; Imaging Techniques; Laboratories; Light; Link; Location; Macaca; Macaca mulatta; Measures; Medical; Modality; Monitor; Monkeys; Neurons; Pathway interactions; Performance; Physiological; Principal Investigator; Process; Public Health; Pump; Signal Transduction; Site; Specificity; Stimulus; Stress; Task Performances; Techniques; Testing; Tissues; Visual; Visual Cortex; Work; alertness; area striata; base; hemodynamics; insight; neuroimaging; neuromechanism; novel; optical imaging; programs; response; tool; visual process; visual processing

Program Director/Principal Investigator (Last, First, Middle): PROJECT SUMMARY Our long-term goal is to understand the neural mechanisms of visual processing early in the cortical pathway. To this end we record from rhesus macaque visual cortex using a combination of intrinsic-signal optical imaging and electrophysiology while the animals are engaged in visual form processing tasks. The goal of the current project is two-fold. We propose to study a novel stimulus-independent anticipatory haemodynamic signal that we observed earlier in alert macaque V1 (primary visual cortex). Through this process we also propose to better understand the physiological basis of neuroimaging signals including fMRI. This project derives from our recent discovery that haemodynamic signals in alert monkey V1 have two distinct components. One component is predictable by visual input and associated V1 neuronal activity. The other component - of comparable strength - is a hitherto unknown haemodynamic signal marking task anticipation. It reflects an arterial pumping mechanism bringing fresh blood to cortex in anticipation of predicted visual events. Electrode recordings conducted simultaneously with the optical imaging showed that this novel haemodynamic signal is not driven by local V1 neuronal activity, in dramatic contrast to visually evoked responses obtained from the same recording sites. We hypothesize that the anticipatory stimulus-independent haemodynamic signal is a mechanism of predictive arousal. We propose to test this hypothesis by characterizing the anticipatory and visually evoked signals, and their interaction, and asking if the anticipatory signal can modulate visually evoked responses and behavior. Our finding of the novel haemodynamic signal also challenges current understandings of neuroimaging signals, notably functional magnetic resonance imaging (fMRI), the most commonly used tool for human neuroimaging. Through the course of this project we will investigate the links between neuroimaging signals and electrophysiology in the alert macaque in a variety of visual perceptual tasks. This will be an unparalleled opportunity to gain new insights into fMRI in an animal model that is the closest possible to the human. Our novel findings were obtained as a result of a new imaging technique developed in our laboratory, continuous dual-wavelength intrinsic-signal optical imaging, combined with electrode recordings, in alert behaving macaques. For the imaging, one wavelength is absorbed preferentially in oxygenated haemoglobin, thus monitoring blood oxygenation; the other wavelength, absorbed equally in oxygenated and deoxygenated haemoglobin, measures blood volume. The simultaneous electrode recordings give an electrophysiological measure of the underlying neuronal activity. The continuous recording allows us to distinguish between ongoing signals and stimulus-evoked responses. This technique will form the basis of the current project, giving a unique combination of tools to answer the questions at hand. PHS 398/2590 (Rev. 11/07) Page Continuation Format Page

计划主任/首席研究员（最后，第一，中间）： 项目摘要 我们的长期目标是了解皮质途径早期视觉处理的神经机制。 为此，我们使用固有信号光学的组合从恒河猕猴视觉皮层记录 当动物从事视觉形式处理任务时，成像和电生理学。 当前项目的目标是两个方面。我们建议研究一种新型刺激独立的预期 我们在警报猕猴V1（主要视觉皮层）中观察到的血液动力学信号。通过这个 过程我们还建议更好地了解包括fMRI在内的神经影像学信号的生理基础。 该项目源于我们最近的发现，即警报中的血液动力学信号有两个不同的 成分。一个成分是可以通过视觉输入和相关的V1神经元活性来预测的。另一个 具有可比强度的成分是迄今未知的血流动力信号标记任务预期。它 反映了一种动脉抽水机制，可预测预测的视觉事件，将新鲜的血液带到皮层。 与光学成像同时进行的电极记录表明，这种新型血流动力学 信号不是由局部V1神经元活性驱动的，与获得的视觉诱发响应形成鲜明对比 来自相同的录音网站。 我们假设预期刺激无关的血液动力学信号是一种预测的机制 唤醒。我们建议通过表征预期和视觉诱发的信号以及 它们的相互作用，并询问预期信号是否可以调节视觉唤起的响应和行为。 我们对新型血液动力学信号的发现也挑战了当前对神经影像学信号的理解， 值得注意的功能性磁共振成像（fMRI），这是用于人类神经成像的最常用工具。 通过该项目的过程，我们将研究神经影像信号与 在各种视觉感知任务中，警报猕猴中的电生理学。这将是无与伦比的 在最接近人类的动物模型中获得对fMRI的新见解的机会。 我们的新颖发现是由于在我们的实验室中开发的新成像技术而获得的 连续双波长固有信号光学成像，与电极记录结合在一起，警报 行为猕猴。对于成像，一个波长在氧化血红蛋白中优先吸收 从而监测血液氧合；其他波长，在氧化和脱氧中平均吸收 血红蛋白，测量血量。同时的电极记录提供了电生理学 衡量基础神经元活性。连续记录使我们能够区分 持续的信号和刺激引起的响应。该技术将构成当前项目的基础， 提供独特的工具组合来回答手头的问题。 PHS 398/2590（Rev. 11/07）页面延续格式页面