OBJECTIVE: Sleep spindles and K-complexes are EEG hallmarks of non-REM sleep. However, the brain regions generating these discharges and the functional connections of their generators to other regions are not fully known. We investigated the neuroanatomical correlates of spindles and K-complexes using simultaneous EEG and fMRI. METHODS: EEGs recorded during EEG-fMRI studies of 7 individuals were used for fMRI analysis. Higher-level group analyses were performed, and images were thresholded at Z ≥ 2.3. RESULTS: fMRI of 106 spindles and 60 K-complexes was analyzed. Spindles corresponded to increased signal in thalami and posterior cingulate, and right precuneus, putamen, paracentral cortex, and temporal lobe. K-complexes corresponded to increased signal in thalami, superior temporal lobes, paracentral gyri, and medial regions of the occipital, parietal and frontal lobes. Neither corresponded to regions of decreased signal. CONCLUSIONS: fMRI of both spindles and K-complexes depicts signal subjacent to the vertex, which likely indicates each discharges' source. The thalamic signal is consistent with thalamic involvement in sleep homeostasis. The limbic region's signal is consistent with roles in memory consolidation. Unlike the spindle, the K-complex corresponds to extensive signal in primary sensory cortices. SIGNIFICANCE: Identification of these active regions contributes to the understanding of sleep networks and the physiology of awareness and memory during sleep.
OBJECTIVE: Sleep spindles and K-complexes are EEG hallmarks of non-REM sleep. However, the brain regions generating these discharges and the functional connections of their generators to other regions are not fully known. We investigated the neuroanatomical correlates of spindles and K-complexes using simultaneous EEG and fMRI. METHODS: EEGs recorded during EEG-fMRI studies of 7 individuals were used for fMRI analysis. Higher-level group analyses were performed, and images were thresholded at Z ≥ 2.3. RESULTS: fMRI of 106 spindles and 60 K-complexes was analyzed. Spindles corresponded to increased signal in thalami and posterior cingulate, and right precuneus, putamen, paracentral cortex, and temporal lobe. K-complexes corresponded to increased signal in thalami, superior temporal lobes, paracentral gyri, and medial regions of the occipital, parietal and frontal lobes. Neither corresponded to regions of decreased signal. CONCLUSIONS: fMRI of both spindles and K-complexes depicts signal subjacent to the vertex, which likely indicates each discharges' source. The thalamic signal is consistent with thalamic involvement in sleep homeostasis. The limbic region's signal is consistent with roles in memory consolidation. Unlike the spindle, the K-complex corresponds to extensive signal in primary sensory cortices. SIGNIFICANCE: Identification of these active regions contributes to the understanding of sleep networks and the physiology of awareness and memory during sleep.
Authors: P Anderer; G Klösch; G Gruber; E Trenker; R D Pascual-Marqui; J Zeitlhofer; M J Barbanoj; P Rappelsberger; B Saletu Journal: Neuroscience Date: 2001 Impact factor: 3.590
Authors: Sydney S Cash; Eric Halgren; Nima Dehghani; Andrea O Rossetti; Thomas Thesen; Chunmao Wang; Orrin Devinsky; Ruben Kuzniecky; Werner Doyle; Joseph R Madsen; Edward Bromfield; Loránd Eross; Péter Halász; George Karmos; Richárd Csercsa; Lucia Wittner; István Ulbert Journal: Science Date: 2009-05-22 Impact factor: 47.728
Authors: M Schabus; T T Dang-Vu; G Albouy; E Balteau; M Boly; J Carrier; A Darsaud; C Degueldre; M Desseilles; S Gais; C Phillips; G Rauchs; C Schnakers; V Sterpenich; G Vandewalle; A Luxen; P Maquet Journal: Proc Natl Acad Sci U S A Date: 2007-08-01 Impact factor: 11.205
Authors: Zhuo Fang; Dylan M Smith; Evan Houldin; Laura Ray; Adrian M Owen; Stuart Fogel Journal: Brain Imaging Behav Date: 2021-08-25 Impact factor: 3.978
Authors: Julie A E Christensen; Miki Nikolic; Simon C Warby; Henriette Koch; Marielle Zoetmulder; Rune Frandsen; Keivan K Moghadam; Helge B D Sorensen; Emmanuel Mignot; Poul J Jennum Journal: Front Hum Neurosci Date: 2015-05-01 Impact factor: 3.169