1. Magnetoencephalography Demonstrates Multiple Asynchronous Generators During Human Sleep Spindles
- Author
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Nima Dehghani, Sydney S. Cash, Andrea O. Rossetti, Eric Halgren, Chih Chuan Chen, Unité de Neurosciences Information et Complexité [Gif sur Yvette] (UNIC), Centre National de la Recherche Scientifique (CNRS), Institut de Neurobiologie Alfred Fessard (INAF), Department Neurology, Department of Neurosurgery, MGH, Harvard University [Cambridge], Service de Neurologie, Centre Universitaire Hospitalier Vaudois, Department of Neurology, National Taiwan University Hospital, Multimodal Imaging Laboratory, Department Radiology and Neurosciences (UCSD), University of California [San Diego] (UC San Diego), and University of California-University of California
- Subjects
Adult ,Male ,MESH: Magnetoencephalography ,Physiology ,[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,Thalamus ,Sleep spindle ,Electroencephalography ,Young Adult ,Cortex (anatomy) ,MESH: Electroencephalography ,medicine ,Humans ,MESH: Cortical Synchronization ,Cortical Synchronization ,MESH: Principal Component Analysis ,Principal Component Analysis ,Sleep Stages ,MESH: Humans ,[SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior ,medicine.diagnostic_test ,General Neuroscience ,Magnetoencephalography ,[SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences ,MESH: Adult ,Articles ,MESH: Sleep Stages ,Sleep in non-human animals ,MESH: Male ,medicine.anatomical_structure ,nervous system ,MESH: Young Adult ,Data Interpretation, Statistical ,Female ,Psychology ,MESH: Data Interpretation, Statistical ,MESH: Female ,Neuroscience - Abstract
International audience; Sleep spindles are approximately 1 s bursts of 10-16 Hz activity that occur during stage 2 sleep. Spindles are highly synchronous across the cortex and thalamus in animals, and across the scalp in humans, implying correspondingly widespread and synchronized cortical generators. However, prior studies have noted occasional dissociations of the magnetoencephalogram (MEG) from the EEG during spindles, although detailed studies of this phenomenon have been lacking. We systematically compared high-density MEG and EEG recordings during naturally occurring spindles in healthy humans. As expected, EEG was highly coherent across the scalp, with consistent topography across spindles. In contrast, the simultaneously recorded MEG was not synchronous, but varied strongly in amplitude and phase across locations and spindles. Overall, average coherence between pairs of EEG sensors was approximately 0.7, whereas MEG coherence was approximately 0.3 during spindles. Whereas 2 principle components explained approximately 50% of EEG spindle variance, >15 were required for MEG. Each PCA component for MEG typically involved several widely distributed locations, which were relatively coherent with each other. These results show that, in contrast to current models based on animal experiments, multiple asynchronous neural generators are active during normal human sleep spindles and are visible to MEG. It is possible that these multiple sources may overlap sufficiently in different EEG sensors to appear synchronous. Alternatively, EEG recordings may reflect diffusely distributed synchronous generators that are less visible to MEG. An intriguing possibility is that MEG preferentially records from the focal core thalamocortical system during spindles, and EEG from the distributed matrix system.
- Published
- 2010