Neuroscience
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Working memory (WM) refers to the holding and manipulation of information during cognitive tasks. Its underlying neural mechanisms have been explored through both functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). Trial-by-trial coupling of simultaneously collected EEG and fMRI signals has become an important and promising approach to study the spatio-temporal dynamics of such cognitive processes. ⋯ Additionally, the activation of single-trial P3 amplitudes was detected in multiple brain regions, including the insula, the cuneus, the lingual gyrus (LG), and the middle occipital gyrus (MOG). Moreover, we found significant correlations between P3 features and behavioral performance. These findings suggest that the single-trial integration of simultaneous EEG and fMRI signals may provide new insights into classical cognitive functions.
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Stress-induced neural injuries are closely linked to the pathogenesis of various neuropsychiatric disorders and psychosomatic diseases. We and others have previously demonstrated certain protective effects of epigallocatechin-3-gallate (EGCG) in stress-induced cerebral impairments, but the underlying protective mechanisms still remain poorly elucidated. Here we provide evidence to support the possible involvement of PKCα and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways in EGCG-mediated protection against restraint stress-induced neural injuries in rats. ⋯ Furthermore, the stress-induced decrease of PKCα and ERK1/2 expression and phosphorylation was significantly attenuated by EGCG and to a less extent by GTP administration. Additionally, EGCG supplementation restored the production of adenosine triphosphate (ATP) and the expression of a key regulator of cellular energy metabolism, the peroxisome proliferators-activated receptor-γ coactivator-1α (PGC-1α), in stressed animals. In conclusion, PKCα and ERK1/2 signaling pathways as well as PGC-1α-mediated ATP production might be involved in EGCG-mediated protection against stress-induced neural injuries.
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Glioblastoma multiforme (GBM) is among the most lethal of all human tumors. It is the most frequently occurring malignant primary brain tumor in adults. The current standard of care (SOC) for GBM is initial surgical resection followed by treatment with a combination of temozolomide (TMZ) and ionizing radiation (IR). ⋯ This was verified in all cell lines by western blot analysis. Furthermore, the combination of TMZ and GDC-0941 with or without IR reduced the levels of p-AKT and O6-methylguanine DNA methyltransferase (MGMT) in T98G cells. The results of this study suggest that the combination of TMZ, IR, and GDC-0941 is a promising choice for future treatments of GBM.
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Inward rectifying potassium - Kir - channels drive the resting potential to potassium reversal potential and, when disrupted, might be related to muscular diseases. Recently, Thyrotoxic Periodic Paralysis (TPP) has emerged as a channelopathy related to mutations in KCNJ18 gene, which encodes Kir2.6 channel. TPP is a neuromuscular disorder characterized by a triad of muscle weakness, hypokalemia, and thyrotoxicosis, the latter being essential for the crisis. ⋯ The mutant D252N Kir2.6 channel also showed a substantial reduction of ∼51% in membrane abundance relative to WT channel. Our study describes the functional consequences of a single amino acid change in Kir2.6 channel. Further analysis regarding hormonal conditions and Kir channel expression are required to provide new clues about the TPP pathophysiology.
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Imaging studies have described hemodynamic activity during fear conditioning protocols with stimulus trains in which a visual conditioned stimulus (CS+) is paired with an aversive unconditioned stimulus (US, painful laser pulse) while another visual stimulus is unpaired (CS-). We now test the hypothesis that CS Event Related Spectral Perturbations (ERSPs) are related to ratings of CS Expectancy (likelihood of pairing with the US), Valence (unpleasantness) and Salience (ability to capture attention). ERSP windows in EEG were defined by both time after the CS and frequency, and showed increased oscillatory power (Event Related Synchronization, ERS) in the Delta/Theta Windows (0-8Hz) and the Gamma Window (30-55Hz). ⋯ The CS Valence and Salience were greater for CS+ than CS-, and were correlated with each other and with the ERD at overlapping channels, particularly in the Alpha Window. Expectancy and CS Skin Conductance Response were greater for CS+ than CS- and were correlated with ERSP at fewer channels than Valence or Salience. These results suggest that Alpha ERSP activity during fear conditioning reflects Valence and Salience of the CSs more than conditioning per se.