期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：33
页码：12348-12353
DOI：10.1073/pnas.0308470101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We tested the hypothesis that behavioral context modulates phase-locking between rhythmic motor activity and concomitant electrical activity induced in primary sensory (S1) cortex. We used exploratory whisking by rat as a model system and recorded two measures: (i) the mystacial electromyogram ({nabla}EMG) as a surrogate of vibrissa position, and (ii) the field potential ({nabla}LFP) in S1 cortex as an indicator of electrical activity. The degree to which the {nabla}EMG and {nabla}LFP were phase-locked was compared for three categories of rhythmic whisking: (i) searching for an object with the vibrissae for a food reward, (ii) whisking in air for the goal of returning to the home cage, and (iii) whisking with no reward. We observed that the magnitude of phase-locking was nearly tripled for the two rewarded conditions compared to unrewarded whisking. Critically, increased locking was not accompanied by an increase in the amplitude of the cortical {nabla}LFP for the rewarded tasks. Additional experiments showed that there was no significant relation between the amplitude of a sensory-evoked response in S1 cortex and the magnitude of the locking between the {nabla}EMG and the {nabla}LFP during whisking. We conclude that the behavioral context of a whisking task can increase the modulation of S1 cortical activity by motor output without a concomitant increase in the magnitude of activity.
