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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Incidences of seizure after e-cigarette use in adolescents and young adults have been reported, raising the concern about the risk of nicotine overconsumption. Few previous studies have investigated the effects of nicotine at high doses on brain and behavior in adolescent animals. In this study, the effects of a 15-day repeated nicotine treatment at a daily dose of 2 mg/kg body weight were investigated in adolescent and adult male rats. ⋯ Only the nicotine-treated adolescents showed significant changes in brain anatomy 1 day post-treatment, which manifested as a significant reduction of whole-brain gray matter (GM) volume, a further reduction of regional GM volume in the medial prefrontal cortex (mPFC) and altered GM volume covariations between the mPFC and a number of brain regions. The mPFC of nicotine-treated adolescent rats did not exhibit evident signs of neuronal degeneration and reactive astrocytosis, but showed a significantly decreased expression of presynaptic marker synaptophysin (SYN), along with a significantly increased oxidative stress and a significantly elevated expressions of microglial marker ionized calcium binding adaptor molecule 1 (IBA1). Together, these results suggested that repeated nicotine overdosing may shift regional redox, modulate microglia-mediated pruning, and give rise to structural/connectivity deficits in the mPFC of adolescent male rats.
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Hypothyroidism is known to affect memory consolidation, and our prior research highlighted the potential of chrysin as a therapeutic agent to restore cognitive function. The present study aimed to investigate the action mechanism of chrysin on memory deficits in hypothyroid in C57BL/6 female mice. We assessed cognitive flexibility, declarative, working, and aversive memories while analyzing the BDNF/TrkB/AKT/Creb neuroplasticity signaling pathway and synaptic function in the hippocampus and prefrontal cortex. ⋯ Chrysin treatment effectively reversed these memory deficits, restored cognitive flexibility, and improved protein levels. Our findings suggest that hypothyroidism impairs cognitive flexibility and memory through the BDNF/TrkB/AKT/Creb pathway, which chrysin modulates, operating as a neuroprotector in hypothyroidism. This research sheds light on the potential therapeutic benefits of chrysin for memory-related issues in hypothyroidism.
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Bayesian brain theory, a computational framework grounded in the principles of Predictive Processing (PP), proposes a mechanistic account of how beliefs are formed and updated. This theory assumes that the brain encodes a generative model of its environment, made up of probabilistic beliefs organized in networks, from which it generates predictions about future sensory inputs. The difference between predictions and sensory signals produces prediction errors, which are used to update belief networks. In this article, we introduce the fundamental principles of Bayesian brain theory, and show how the brain dynamics of prediction are associated with the generation and evolution of beliefs.
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The association of neuroticism and cerebral small vessel disease (CSVD) development remains unclear. In this study, we used Mendelian randomization (MR) to explore the potential role of neuroticism in CSVD development. ⋯ This research suggests a potential correlation between certain aspects of neuroticism and CSVD, with further studies needed to better understand the causal relationship and its implications for patient intervention.