Zobrazení zdroje stránky Dalrymplekirk1021

It is well established that identification of words in noise improves when it is preceded by a semantically related word, but comparatively little is known about the effect of subsequent context in guiding word in noise identification. We build on the findings of a previous behavioural study (Chan &amp; Alain, 2019) by measuring neuro-electric brain activity while manipulating the semantic content of a cue that either preceded or followed a word in noise. Participants were more accurate in identifying the word in noise when it was preceded or followed by a cue that was semantically related. This gain in accuracy coincided with a late positive component, which was time-locked to the word in noise when preceded by a cue and time-locked to the cue when it followed the word in noise. Distributed source analyses of this positive component revealed different patterns in source activity between the two temporal conditions. The effects of relatedness also generated an event-related potential modulation around 400 ms (N400) that was present at cue presentation when it followed the word in noise, but not for the word in noise when preceded by the cue, consistent with findings regarding its sensitivity to signal degradation. Exploratory analyses examined a subset of data based on participants' subjective perceived clarity, which revealed a posterior deflection over the left hemisphere that showed a relatedness effect. We discuss these findings in light of research on prediction as well as a reflective attention framework.Sensory processing is the gateway to information processing and more complex processes such as learning. Alterations in sensory processing is a common phenotype of many genetic syndromes associated with intellectual disability (ID). [https://www.selleckchem.com/products/d-lin-mc3-dma.html https://www.selleckchem.com/products/d-lin-mc3-dma.html] It is currently unknown whether sensory processing alterations converge or diverge on brain responses between syndromes. Here, we compare for the first time four genetic conditions with ID using the same basic sensory learning paradigm. One hundred and five participants, aged between 3 and 30 years old, composing four clinical ID groups and one control group, were recruited Fragile X syndrome (FXS; n = 14), tuberous sclerosis complex (TSC; n = 9), Down syndrome (DS; n = 19), SYNGAP1 mutations (n = 8) and Neurotypical controls (NT; n = 55)). All groups included female and male participants. Brain responses were recorded using electroencephalography (EEG) during an audio-visual task that involved three repetitions of the pronunciation of the phoneme /a/. Event Related Potentials (ERP) were used to 1) compare peak-to-peak amplitudes between groups, 2) evaluate the presence of repetition suppression within each group and 3) compare the relative repetition suppression between groups. Our results revealed larger overall amplitudes in FXS. A repetition suppression (RS) pattern was found in the NT group, FXS and DS, suggesting spared repetition suppression in a multimodal task in these two ID syndromes. Interestingly, FXS presented a stronger RS on one peak-to-peak value in comparison with the NT. The results of our study reveal the distinctiveness of ERP and RS brain responses in ID syndromes. Further studies should be conducted to understand the molecular mechanisms involved in these patterns of responses.<br /><br /> Peripheral nerve injuries are a common clinical problem which may result in permanent loss of motor or sensory function. A better understanding of the signaling pathways that lead to successful nerve regeneration may help in discovering new therapeutic targets. The Hedgehog (Hh) signaling pathway plays significant roles in nerve development and regeneration. In a mouse model of facial nerve injury, Hedgehog-responsive fibroblasts increase in number both at the site of injury and within the distal nerve. However, the role of these cells in facial nerve regeneration is not fully understood. We hypothesize that the Hh pathway plays an angiogenic and pro-migratory role following facial nerve injury.<br /><br /> Hedgehog pathway modulators were applied to murine endoneurial fibroblasts isolated from the murine facial nerve. The impact of pathway modulation on endoneurial fibroblast migration and cell proliferation was assessed. Gene expression changes of known Hedgehog target genes and the key angiogenic factor Vegf-A wernic and pro-migratory role for the Hedgehog pathway mediated through effects on nerve fibroblasts. Given the critical role of Vegf-A in nerve regeneration, modulation of this pathway may represent a potential therapeutic target to improve facial nerve regeneration following injury.Although conformational dynamics of RNA molecules are potentially important in microRNA (miRNA) processing, the role of the protein binding partners in facilitating the requisite structural changes is not well understood. In previous work, we and others have demonstrated that nonduplex structural elements and the conformational flexibility they support are necessary for efficient RNA binding and cleavage by the proteins associated with the two major stages of miRNA processing. However, recent studies showed that the protein DGCR8 binds primary miRNA and duplex RNA with similar affinities. Here, we study RNA binding by a small recombinant construct of the DGCR8 protein and the RNA conformation changes that result. This construct, the DGCR8 core, contains two double-stranded RNA-binding domains (dsRBDs) and a C-terminal tail. To assess conformational changes resulting from binding, we applied small-angle x-ray scattering with contrast variation to detect conformational changes of primary-miR-16-1 in complex with the DGCR8 core. This method reports only on the RNA conformation within the complex and suggests that the protein bends the RNA upon binding. Supporting work using smFRET to study the conformation of RNA duplexes bound to the core also shows bending. Together, these studies elucidate the role of DGCR8 in interacting with RNA during the early stages of miRNA processing.Terahertz waves have attracted great attention in biomolecule research because of the fact that they cover the range of energy levels of weak interactions, skeleton vibrations, and dipole rotations during inter- and intramolecular interactions in biomacromolecules. In this study, we validated the feasibility of employing terahertz time-domain spectroscopy (THz-TDS) for the nondestructive and label-free monitoring of protein digestion. The acid protease, pepsin, was used at its optimal pH to hydrolyze bovine serum albumin. Correspondingly, the control group experiment was also conducted by adjusting the pH value to inactivate pepsin. The progress of these two experiments was tracked by a compact commercial THz-TDS for 1 h. On one hand, the reaction-time-dependent absorption coefficient was calculated, and a direct absorption coefficient analysis was completed. The results indicate that protein hydrolysis can be easily monitored over time by focusing on the variation tendency of the absorption coefficient from a macroscopic perspective.