Neuroscience
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The aim of this study was to assess the potential causal relationship between lifestyle factors and intracranial aneurysms (IAs) using a two-sample Mendelian randomization (MR) approach. The study used a pooled dataset from a genome-wide association study that covered information on 24 lifestyle factors, intracranial aneurysm cases, subarachnoid hemorrhage, and unruptured aneurysms. Five MR methods were applied for analysis by selecting single nucleotide polymorphisms as instrumental variables, with the inverse variance weighting method as the main method. ⋯ Sensitivity analyses and inverse MR verified the robustness of these results. After adjusting for exposure factors, multivariate MR confirmed daily smoking and smoking initiation as risk factors for intracranial aneurysms, unruptured aneurysms, and subarachnoid hemorrhage, whereas red wine intake was a genetically protective factor against intracranial aneurysms and subarachnoid hemorrhage. This MR analysis revealed a genetic causal link between specific lifestyle factors and intracranial aneurysms, emphasizing the need for further studies to confirm these findings and explore their mechanisms.
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Media multitasking has become pervasive in our daily lives, yet its impact on cognitive abilities remains contentious, with more evidence supporting adverse effects (scattered attention hypothesis) than benefits (trained attention hypothesis). Recent studies have increasingly focused on the training effects of behavioral training on anticipatory brain functions, which involve cognitive and motor preparation before stimulus onset, assessed using event-related potentials (ERPs). This study investigated whether media multitasking enhances anticipatory brain functions and how task difficulty influences this relationship. ⋯ Our results suggest that HMM can flexibly adjust resource allocation based on task demands to maintain their response speed advantage. These findings suggest that LMM may possess a relatively steady acceleration/brake system, whereas HMM exhibit a more adaptable system capable of responding flexibly to diverse situations. Overall, these results underscore the training effects of media multitasking on anticipatory brain functions, supporting the trained attention hypothesis.
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The cerebrospinal fluid-contacting nucleus(CSF-contacting nucleus) is a pair of unique nuclei in the brain parenchyma which has long been demonstrated to play an important role in pain signal processing. However, the mechanisms by which the CSF-contacting nucleus intervenes in pain is unclear. The NRG1-ErbB4 signaling plays an important role in the nervous system and has been shown to be involved in the regulation of pain. ⋯ With immunofluorescence staining and Western blot, the NRG1-ErbB4 signaling in the CSF-contacting nucleus showed upregulated during the acute pain phase. And, activating NRG1-ErbB4 signaling in the CSF-contacting nucleus specifically by intracranial injection of drugs, the naïve mice displayed thermal hyperalgesia while inhibiting this signaling by intracranial injection could reverse the hyperalgesia caused by CSF-contacting nucleus activation, and execute an analgesic effect during the painful phase in mice. Our study suggested that the CSF-contacting nucleus plays a regulatory role in thermal pain in mice via NRG1-ErbB4 signaling.
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Myelination is the process by which oligodendrocytes ensheathe axons to form myelin sheaths. Myelination is a crucial aspect of brain development and is closely associated with central nervous system abnormalities. However, previous studies have found that advanced maternal age might affect the myelination of offspring, potentially through the pathway of disrupting DNA methylation levels in the offspring's hippocampus. ⋯ The demethylation level of oligodendrocyte progenitor cells was detected by immunofluorescence co-expression of OLIG2 and DNA hydroxylase ten-eleven translocation 1 (TET1), TET2, and TET3. Our study found that advanced maternal age could impair myelination in the hippocampus and corpus callosum of offspring. Ascorbic acid intervention may induce TET1 and TET2-mediated hydroxymethylation to ameliorate myelination disorders, promote myelination and maturation, and reverse the effects of advanced maternal age on offspring.
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Prepulse inhibition (PPI) refers to the phenomenon in which a weak sensory stimulus before a strong one significantly reduces the startle reflex caused by the strong stimulus. Perceptual spatial separation, a phenomenon where auditory cues from the prepulse and background noise are distinguished in space, has been shown to enhance PPI. This study aims to investigate the neural modulation mechanisms of PPI by the spatial separation between the prepulse stimulus and background noise, particularly in the deep superior colliculus (deepSC). ⋯ The prepulse stimulus was a segment of narrowband noise, with interaural time differences adjusted so that the prepulse stimulus and background noise were perceived as either ipsilaterally leading or contralaterally leading, resulting in perceptual spatial fusion or spatial separation. The results showed that under conditions of spatial separation, the stimulus-response coherence of the envelope and fine structure components of the prepulse stimulus in the deepSC was significantly enhanced, the response of the deepSC to the stimulus was significantly reduced in the presence of the prepulse stimulus, and the envelope component of the prepulse stimulus was positively correlated with the inhibitory effect. The above results suggest that perceptual spatial dissociation can significantly enhance the expression of deepSC, particularly the precision of the envelope component, thereby significantly affecting the electrophysiological response of PPI.