BackgroundSleep spindles are ∼1-second bursts of 10–15 Hz activity, occurring during normal stage 2 sleep. In animals, sleep spindles can be synchronous across multiple cortical and thalamic locations, suggesting a distributed stable phase-locked generating system. The high synchrony of spindles across scalp EEG sites suggests that this may also be true in humans. However, prior MEG studies suggest multiple and varying generators.Methodology/Principal FindingsWe recorded 306 channels of MEG simultaneously with 60 channels of EEG during naturally occurring spindles of stage 2 sleep in 7 healthy subjects. High-resolution structural MRI was obtained in each subject, to define the shells for a boundary element forward solution and to reconstruct the cortex providing the solution space for a noise-normalized minimum norm source estimation procedure. Integrated across the entire duration of all spindles, sources estimated from EEG and MEG are similar, diffuse and widespread, including all lobes from both hemispheres. However, the locations, phase and amplitude of sources simultaneously estimated from MEG versus EEG are highly distinct during the same spindles. Specifically, the sources estimated from EEG are highly synchronous across the cortex, whereas those from MEG rapidly shift in phase, hemisphere, and the location within the hemisphere.Conclusions/SignificanceThe heterogeneity of MEG sources implies that multiple generators are active during human sleep spindles. If the source modeling is correct, then EEG spindles are generated by a different, diffusely synchronous system. Animal studies have identified two thalamo-cortical systems, core and matrix, that produce focal or diffuse activation and thus could underlie MEG and EEG spindles, respectively. Alternatively, EEG spindles could reflect overlap at the sensors of the same sources as are seen from the MEG. Although our results generally match human intracranial recordings, additional improvements are possible and simultaneous intra- and extra-cranial measures are needed to test their accuracy.

Serum amyloid A (SAA) is not only an apolipoprotein, but also a member of the adipokine family with potential to enhance lipolysis. The purpose of this study was to explore how SAA facilitates lipolysis in porcine adipocytes. We found that SAA increased the phosphorylation of perilipin and hormone‐sensitive lipase (HSL) after 12‐h treatment and decreased perilipin expression after 24‐h treatment, and these effects were prevented by extracellular signal‐regulated kinase (ERK) or protein kinase A (PKA) inhibitors in primary adipocyte cell culture. SAA treatment decreased HSL and adipose triglyceride lipase (ATGL) expression. SAA treatment also activated ERK and PKA by increasing the phosphorylation of these kinases. Moreover, SAA significantly increased porcine adipocyte glycerol release and lipase activity, which was inhibited by either ERK (PD98059) or PKA (H89) inhibitors, suggesting that ERK and PKA were involved in mediating SAA enhanced lipolysis. SAA downregulated the expression of peroxisome proliferator‐activated receptor γ (PPARγ) mRNA, which was reversed by the ERK inhibitor. We performed a porcine perilipin promoter assay in differentiated 3T3–L1 adipocytes and found that SAA reduced the porcine perilipin promoter specifically through the function of its PPAR response element (PPRE), and this effect was reversed by the ERK inhibitor. These findings demonstrate that SAA‐induced lipolysis is a result of downregulation of perilipin and activation of HSL via ERK/PPARγ and PKA signaling pathways. The finding could lead to developing new strategies for reducing human obesity.

Aging is a process associated with a decline in cognitive and motor functions, which can be attributed to neurological changes in the brain. Tai Chi, a multimodal mind-body exercise, can be practiced by people across all ages. Previous research identified effects of Tai Chi practice on delaying cognitive and motor degeneration. Benefits in behavioral performance included improved fine and gross motor skills, postural control, muscle strength, and so forth. Neural plasticity remained in the aging brain implies that Tai Chi-associated benefits may not be limited to the behavioral level. Instead, neurological changes in the human brain play a significant role in corresponding to the behavioral improvement. However, previous studies mainly focused on the effects of behavioral performance, leaving neurological changes largely unknown. This systematic review summarized extant studies that used brain imaging techniques and EEG to examine the effects of Tai Chi on older adults. Eleven articles were eligible for the final review. Three neuroimaging techniques including fMRI (N = 6), EEG (N = 4), and MRI (N = 1), were employed for different study interests. Significant changes were reported on subjects' cortical thickness, functional connectivity and homogeneity of the brain, and executive network neural function after Tai Chi intervention. The findings suggested that Tai Chi intervention give rise to beneficial neurological changes in the human brain. Future research should develop valid and convincing study design by applying neuroimaging techniques to detect effects of Tai Chi intervention on the central nervous system of older adults. By integrating neuroimaging techniques into randomized controlled trials involved with Tai Chi intervention, researchers can extend the current research focus from behavioral domain to neurological level.