音乐对脑的正性影响与机制

文章主要阐述了音乐对脑的多方面正性影响,主要包括空间推理能力的提升(莫扎特效应),学习记忆能力的增强等;在疾病治疗方面,则集中于音乐对精神和神经性疾病,如癫痫、孤独症、帕金森综合症、老年性痴呆等的影响。目前,音乐对机体产生的这些正性影响的具体分子机制还不十分清晰,本文将细述在音乐暴露的情况下,大脑中相关神经细胞的生长、分化、凋亡及蛋白质合成的调控,某些神经递质(如多巴胺,五羟色胺,γ-氨基丁酸等)的合成与释放,类固醇激素分泌对脑内物质合成与分泌的调节,以及BDNF/TrkB信号通路和NGF的调节。     

低氧性脑血管扩张机制研究的概况

低氧可以通过多种机制影响脑血管的张力,改变脑血流量,进而影响脑功能。低氧性脑血管舒张机制是近年研究热点之一。本文从ＮＯ、前列环素、ＡＴＰ敏感Ｋ通道、ＡＴＰ、兴奋性氨基酸、Ｃａ＾＋＋等诸多方面论述了低氧性脑血管舒张可能的作用机制,并就有待解决的若干问题与读者进行讨论。     

肾性尿崩症发生的分子机制

肾性尿崩症发生的分子机制卢建（第二军医大学病理生理教研室,上海２００４３３）关键词肾性尿崩症,分子机制肾脏对水的重吸收和排泄功能受下丘脑神经元合成及分泌的精氨酸加压素（ＡＶＰ）的调节。ＡＶＰ由垂体后叶释放入血,到达肾脏后,与肾集合管管周膜上的Ｖ２受体...     

益生菌对宿主心理健康及脑功能的积极影响及其机制

肠道中的益生菌不仅对胃肠道发挥着益生作用,而且还调节着体内的激素水平和炎症平衡。通过免疫、内分泌和迷走神经途径,益生菌与大脑形成一个称之为脑¬—肠轴的反馈回路,深刻影响着大脑的认知功能及人体的情绪反应,促进宿主的心理健康。     

高气压对脑循环的影响

对32名男性潜水员和25头家兔进行了下列3项内容的观察:1)不同压力下脑阻抗图(REG)的改变;2)模拟潜水时REG的变化与颅内压(ICP)的关系;3)职业潜水员的工令对脑循环的影响。结果表明,在高气压下,REG的波幅、dz/dt和上升时间/心动周期比值均有不同程度的变化。这些指标的变化可以说明博动性脑血容量减少和血管阻力增加,提示脑血流量减少。这些变化主要是由于高分压氧的作用。     

肠脑轴参与动物食欲的调节机制

肠脑轴是由中枢系统、胃肠道系统共同构成的双向通信系统,其主要通过下丘脑食欲中枢和胃肠道食欲激素来调节动物的食欲,控制其体重,参与能量稳态的调节,是研究动物肥胖和2型糖尿病等代谢疾病的重要轴系。本文综述了肠脑轴对动物食欲、能量平衡和体重的调节作用,展望了肠脑轴在肥胖等相关代谢疾病治疗中的研究前景。     

脑衰老机制与脑疾病的关系

衰老是人类生命过程的必然规律,是不可抗拒的自然现象.神经系统是重要的机能调节系统,也是受衰老影响最大的系统之一,衰老的脑组织会产生一些特征性的改变,了解这些改变及其分子机制对衰老的研究具有重要意义.本文就近年来脑与衰老的研究进行综述,以进一步探讨脑衰老和脑衰老相关疾病的机制.     

The influence of genomic imprinting on brain development and behavior

Genomic imprinting, a newly discovered and significant form of gene regulation, refers to the differential expression of a gene depending on whether it is inherited from the male or female parent. The genetic conflict theory of genomic imprinting postulates that conflicts between the genetic interests of mothers, fathers, and their offspring, as well as asymmetric genetic relationships with maternal and paternal kin, led to an evolutionary “arms race” within the genome, which resulted in the expression of these conflicts at the phenotypic level. This paper provides background and evidence regarding genomic imprinting and its role in brain development, describes the cognitive and behavioral phenomena that have been interpreted in terms of the genetic conflict model, and points to potential avenues of further research.     

The influence of anisotropy on brain injury prediction

Traumatic Brain Injury (TBI) occurs when a mechanical insult produces damage to the brain and disrupts its normal function. Numerical head models are often used as tools to analyze TBIs and to measure injury based on mechanical parameters. However, the reliability of such models depends on the incorporation of an appropriate level of structural detail and accurate representation of the material behavior. Since recent studies have shown that several brain regions are characterized by a marked anisotropy, constitutive equations should account for the orientation-dependence within the brain. Nevertheless, in most of the current models brain tissue is considered as completely isotropic. To study the influence of the anisotropy on the mechanical response of the brain, a head model that incorporates the orientation of neural fibers is used and compared with a fully isotropic model. A simulation of a concussive impact based on a sport accident illustrates that significantly lowered strains in the axonal direction as well as increased maximum principal strains are detected for anisotropic regions of the brain. Thus, the orientation-dependence strongly affects the response of the brain tissue. When anisotropy of the whole brain is taken into account, deformation spreads out and white matter is particularly affected. The introduction of local axonal orientations and fiber distribution into the material model is crucial to reliably address the strains occurring during an impact and should be considered in numerical head models for potentially more accurate predictions of brain injury.     

The molecular mechanism of plasma membrane H+-ATPases in plant responses to abiotic stress

Plasma membrane H⁺-ATPases (PM H⁺-ATPases) are critical proton pumps that export protons from the cytoplasm to the apoplast. The resulting proton gradient and difference in electrical potential energize various secondary active transport events. PM H⁺-ATPases play essential roles in plant growth, development, and stress responses. In this review, we focus on recent studies of the mechanism of PM H⁺-ATPases in response to abiotic stresses in plants, such as salt and high pH, temperature, drought, light, macronutrient deficiency, acidic soil and aluminum stress, as well as heavy metal toxicity. Moreover, we discuss remaining outstanding questions about how PM H⁺-ATPases contribute to abiotic stress responses.     

精氨酸抗氧化作用机制

精氨酸是一种功能性氨基酸,在机体生理功能、新陈代谢和营养等方面发挥着重要作用。精氨酸具有抗氧化能力。目前的体外研究表明精氨酸具有较强的清除DPPH自由基、ABTS自由基、超氧自由基能力以及一定的还原力。作为一种带电子的碱性氨基酸,精氨酸可能通过胍基基团向自由基提供电子并与其作用,终止自由基链式反应,从而显示出还原能力与体外抗氧化能力。体内实验则表明精氨酸能有效地提高机体总抗氧化能力,降低体内自由基含量,抑制ROS生成与积累,促进谷胱甘肽(GSH)合成与积累,增强内源性抗氧化酶(CAT、SOD、GPx等)活性,抑制氧化应激的产生。精氨酸能够通过精氨酸——一氧化氮途径、GSH途径、Nrf2信号通路途径及其他途径发挥体内抗氧化作用。本文主要综述了目前精氨酸体外与体内抗氧化功能及其相关作用机制的研究进展,为精氨酸的实际应用提供理论指导意义。     

Reflections on music teacher professional development: Teacher-generated policies and practices

Abstract

The purpose of this article is to make policy recommendations based on the authors’ experiences with, and research about, reflective, differentiated, and teacher-generated music teacher professional development (PD). By doing so, we argue for a bottom-up process that capitalizes on our music teacher and music teacher educator expertise along with the research literature in music teacher PD. We explore music teachers’ PD needs considering four career stages to explain how knowledge generated at each level informs our understanding of differentiated PD. From preservice music teachers and music teacher candidates, to in-service and veteran teachers, our discussion explores meaningful and effective ways to engage in deep, reflective thinking about the music teaching and learning process. Accordingly, we provide specific policy recommendations for music teachers at each career stage so that they might take greater ownership of their own learning, growth, and development through local, reflective, self-initiated, and differentiated PD opportunities.     

结核分枝杆菌的耐药基因及其相关分子机制

结核分枝杆菌原发性和继发性耐药是当前控帝】和治疗结核病面临的重要问题,随着分子遗传学的发展,已经阐明了结核分枝杆菌耐药的分子基础是染色体的突变,影响了药靶本身或激活了药物前体的细菌酶,造成MTB的耐药。本文主要就MTB对其常用药物的耐药机制展开讨论,以便正确认识MTB对不同药物的耐药机制,建立快速检测耐药结核分枝杆菌基因型的分子生物学方法。     

The influence of sex and strain on trace element dysregulation in the brain due to diet-induced obesity

BackgroundThe objective of this study was to identify interaction effects between diet, sex, and strain on trace element dysregulation and gene expression alterations due to diet-induced obesity (DIO) in the hippocampus, striatum, and midbrain.MethodsMale and female C57BL/6 J (B6 J) and DBA/2 J (D2 J) mice were fed either a low fat (10 % kcal) diet (LFD) or high fat (60 % kcal) diet (HFD) for 16 weeks, then assessed for trace element concentrations and gene expression patterns in the brain.ResultsIn the hippocampus, zinc was significantly increased by 48 % in D2 J males but decreased by 44 % in D2 J females, and divalent metal transporter 1 was substantially upregulated in B6 J males due to DIO. In the striatum, iron was significantly elevated in B6 J female mice, and ceruloplasmin was significantly upregulated in D2 J female mice due to DIO. In the midbrain, D2 J males fed a HFD had a 48 % reduction in Cu compared to the LFD group, and D2 J females had a 37 % reduction in Cu compared to the control group.ConclusionsThe alteration of trace element homeostasis and gene expression due to DIO was brain-region dependent and was highly influenced by sex and strain. A significant three-way interaction between diet, sex, and strain was discovered for zinc in the hippocampus (for mice fed a HFD, zinc increased in male D2 Js, decreased in female D2 Js, and had no effect in B6 J mice). A significant diet by sex interaction was observed for iron in the striatum (iron increased only in female mice fed a HFD). A main effect of decreased copper in the midbrain was found for the D2 J strain fed a HFD. These results emphasize the importance of considering sex and genetics as biological factors when investigating potential associations between DIO and neurodegenerative disease.     

结核分枝杆菌的耐药基因及其相关分子机制

结核分枝杆菌原发性和继发性耐药是当前控制和治疗结核病面临的重要问题,随着分子遗传学的发展,已经阐明了结核分枝杆菌耐药的分子基础是染色体的突变,影响了药靶本身或激活了药物前体的细菌酶,造成MTB的耐药。本文主要就MTB对其常用药物的耐药机制展开讨论,以便正确认识MTB对不同药物的耐药机制,建立快速检测耐药结核分枝杆菌基因型的分子生物学方法。