title: Intrinsic signal optical imaging of visual brain activity: Tracking of fast cortical dynamics.
abstract: Hemodynamic-based brain imaging techniques are typically incapable of monitoring brain activity with both high spatial and high temporal resolutions. In this study, we have used intrinsic signal optical imaging (ISOI), a relatively high spatial resolution imaging technique, to examine the temporal resolution of the hemodynamic signal. We imaged V1 responses in anesthetized monkey to a moving light spot. Movies of cortical responses clearly revealed a focus of hemodynamic response traveling across the cortical surface. Importantly, at different locations along the cortical trajectory, response timecourses maintained a similar tri-phasic shape and shifted sequentially across cortex with a predictable delay. We calculated the time between distinguishable timecourses and found that the temporal resolution of the signal at which two events can be reliably distinguished is about 80 milliseconds. These results suggest that hemodynamic-based imaging is suitable for detecting ongoing cortical events at high spatial resolution and with temporal resolution relevant for behavioral studies.
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning, Collaborative Innovation Center for Brain Science, Beijing Normal University, Beijing, China; Department of Psychology, Vanderbilt University, Nashville, TN, USA. Electronic address: haidong@bnu.edu.cn.
authors.forename: Haidong D
authors.initials: HD
authors.lastname: Lu
authors.affiliation: Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China; Department of Psychology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Cai
authors.affiliation: Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China; Department of Psychology, Vanderbilt University, Nashville, TN, USA; Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA.
authors.forename: Anna W
authors.initials: AW
authors.lastname: Roe
mesh_terms: D000758:Anesthesia; D000818:Animals; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D006439:Hemodynamics; D008253:Macaca mulatta; D009038:Motion; D059906:Neuroimaging / Q000379:methods*; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*
keywords: Intrinsic signal optical imaging; Monkey; Temporal resolution; V1; Visual cortex