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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Previous research has demonstrated that aerobic exercise has disparate effects on speed of processing and movement execution. In simple and choice reaction tasks, aerobic exercise appears to increase speed of movement execution while speed of processing is unaffected. In the flanker task, aerobic exercise has been shown to reduce response time on incongruent trials more than congruent trials, purportedly reflecting a selective influence on speed of processing related to cognitive control. ⋯ Reaction time during incongruent flanker trials decreased over time in both an aerobic exercise and non-exercise control condition indicating it was not specifically influenced by exercise. This disparate influence of aerobic exercise on movement time and reaction time indicates the importance of partitioning response time when examining the influence of aerobic exercise on speed of processing. The decrease in reaction time over time independent of aerobic exercise indicates that interpreting pre-to-post exercise changes in behavior requires caution.
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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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Heightened concentrations of CO2 in inhaled air provoke temporary acidification of the brain, followed by compensatory hyperventilation and increased arousal/anxiety. These responses are likely to map a basic, latent general alarm/avoidance system that is largely shared across mammals, and are sources of individual differences. By showing paroxysmal respiratory and emotional responses to CO2 challenges, humans with panic and separation anxiety disorders lie at one extreme of the distribution for CO2 sensitivity. ⋯ Advantages of modeling CO2 sensitivity in rodents include non-inferential measurements (e.g. respiratory readouts) as proxies for human conditions, unbiased investigation of gene-environment interplays, and flexible availability of tissues for mechanistic studies. Data in humans and animals such as those reported in this issue of Neuroscience begin to reveal that CO2-driven behavioral responses stem from anatomo-physiological systems that are relatively separated from those subserving general dispositions to anxiety. This supports the notion that sensitivity to suffocative stimuli and ensuing human panic are significantly independent from trait/cognitive anxiety, and corroborates newer conceptualizations that distinguish between fear and anxiety circuitries.
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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.