Paper Info
Title
Broadband Local Field Potentials Correlate With Spontaneous Fluctuations In Functional Magnetic Resonance Imaging Signals In The Rat Somatosensory Cortex Under Isoflurane Anesthesia
Abstract
Resting-state functional magnetic resonance imaging (fMRI) is widely used for exploring spontaneous brain activity and large-scale networks; however, the neural processes underlying the observed resting-state fMRI signals are not fully understood. To investigate the neural correlates of spontaneous low-frequency fMRI fluctuations and functional connectivity, we developed a rat model of simultaneous fMRI and multiple-site intracortical neural recordings. This allowed a direct comparison to be made between the spontaneous signals and interhemispheric connectivity measured with the two modalities. Results show that low-frequency blood oxygen level-dependent (BOLD) fluctuations (<0.1 Hz) correlate significantly with slow power modulations ( < 0.1 Hz) of local field potentials (LFPs) in a broad frequency range (1-100 Hz) under isoflurane anesthesia (1%-1.8%). Peak correlation occurred between neural and hemodynamic activity when the BOLD signal was delayed by similar to 4 sec relative to the LFP signal. The spatial location and extent of correlation was highly reproducible across studies, with the maximum correlation localized to a small area surrounding the site of microelectrode recording and to the homologous area in the contralateral hemisphere for most rats. Interhemispheric connectivity was calculated using BOLD correlation and band-limited LFP (1-4, 4-8, 8-14,14-25, 25-40, and 40-100 Hz) coherence. Significant coherence was observed for the slow power changes of all LFP frequency bands as well as in the low-frequency BOLD data. A preliminary investigation of the effect of anesthesia on interhemispheric connectivity indicates that coherence in the high-frequency LFP bands declines with increasing doses of isoflurane, whereas coherence in the low-frequency LFP bands and the BOLD signal increases. These findings suggest that resting-state fMRI signals might be a reflection of broadband LFP power modulation, at least in isoflurane-anesthetized rats.
Year
DOI
Venue
2011
10.1089/brain.2011.0014
BRAIN CONNECTIVITY
Keywords
Field
DocType
anesthetic effects, broadband LFP, functional connectivity, neural correlates, resting-state fMRI
Neural correlates of consciousness,Neuroscience,Functional magnetic resonance imaging,Anesthesia,Resting state fMRI,Brain activity and meditation,Somatosensory system,Local field potential,Medicine,Isoflurane,Magnetic resonance imaging
Journal
Volume
Issue
ISSN
1
2
2158-0014
Citations 
PageRank 
References 
23
1.40
4
Authors
6
Name
Order
Citations
PageRank
Wen-Ju Pan11709.64
Garth John Thompson21558.55
Matthew Magnuson31376.71
Waqas Majeed41005.51
Dieter Jaeger51034.75
Shella D. Keilholz653325.92