短期整体身心调节法的全身皮肤电导反应规律(英文)

目的:探讨短期整体身心调节法练习者的全身皮肤电导反应特点。方法:采用单因素完全随机实验设计,将68名在校大学生分为整体身心调节组和放松组,分别进行为期10天的整体身心调节训练和经典的肌肉放松训练,并于训练前和训练结束后,测试两组学生身体7个分支的皮肤电导反应。结果:训练前,大学生前3支皮肤电导反应大于后4支;训练10天后,与训练前相比,整体身心调节训练组第1、2支皮肤电导反应显著减小,7个分支的皮肤电导反应出现均衡的规律;放松训练组学生身体7个分支皮肤电导反应变化不显著。结论:短期整体身心调节法形成了全身皮肤电导反应的均衡,可能反映短期整体身心调节法的整体身心相互作用原理。     

短期整体身心调节法的全身皮肤电导反应规律

目的：探讨短期整体身心调节法练习者的全身皮肤电导反应特点。方法：采用单因素完全随机实验设计,将68名在校大学生分为整体身心调节组和放松组,分别进行为期10天的整体身心调节训练和经典的肌肉放松训练,并于训练前和训练结束后,测试两组学生身体7个分支的皮肤电导反应。结果：训练前,大学生前3支皮肤电导反应大于后4支;训练10天后,与训练前相比,整体身心调节动I练组第1、2支皮肤电导反应显著减小,7个分支的皮肤电导反应出现均衡的规律;放松训练组学生身体7个分支皮肤电导反应变化不显著。结论：短期整体身心调节法形成了全身皮肤电导反应的均衡,可能反映短期整体身心调节法的整体身心相互作用原理。     

体育运动训练增强肌肉可塑性和大脑可塑性

体育运动训练改变肌肉和大脑的结构和功能。运动训练可以增加肌肉中毛细血管的数量,改变肌原纤维的比例,刺激多种细胞因子和肌肉因子的合成与分泌,增加肌肉体积,增强肌肉力量。相反,身体活动长期受限则会使肌肉体积减小,肌肉力量下降。另外,运动训练还会使大脑部分脑区的灰质体积增加,促进神经发生,促进脑血管增生,改变大脑激活模式及其结构和功能联结,增加神经营养因子水平。这些作用受运动类型、运动时长、运动强度的影响或调节。目前我们对肌肉可塑性与大脑可塑性之间关系的了解还十分有限。运动相关的代谢过程与肌肉收缩的分泌物可能与大脑可塑性有密切关系。本综述为倡导运动锻炼,制定科学的运动和康复方案提供理论依据和实践指导。     

基于表面的形态学分析在音乐家大脑结构磁共振成像中的应用

研究训练导致的脑可塑性变化对于理解人类大脑的功能是极其重要的,而音乐家的大脑是研究此类问题的一个理想模型。文章通过对性别年龄相匹配的16位音乐家和16位非音乐家大脑的结构磁共振成像进行基于皮层表面的脑形态学分析,统计对比了大脑皮层的一阶及二阶形态特征。结果显示:音乐家在枕上回、颞上沟、顶下小叶及中央旁小叶区域具有更大的皮层表面积;在胼胝体附近皮层展示出更高的平均皮层厚度;在枕叶、颞叶、额叶及顶叶中与视觉、躯体运动、情绪、运动控制、听觉及躯体感觉等功能相关的若干脑区,展示出更高的皮层形态复杂度。长期的音乐训练可能会使得音乐家大脑在基本的感知和运动系统,以及情绪相关脑区,具有更显著的皮层形态特征改善。这些结果为我们更好地理解音乐训练相关的大脑结构可塑性增添了新的证据。     

再可塑性在学习记忆中作用的研究进展

突触可塑性是学习记忆功能的重要细胞机制,也是神经科学领域的研究热点之一,其中长时程增强(long-term potentiation,LTP)与长时程抑制(long-term depression,LTD)是突触可塑性的两种主要表现形式。作为突触可塑性高级形式的再可塑性(metaplasticity),是指突触可塑性的可塑性,即突触活动的过往史对后继的突触可塑性产生影响,这表明突触的可塑性依赖于当前的突触"状态",因此对探究大脑学习记忆功能与疾病对认知的影响具有重要意义。自再可塑性的概念提出以来,便引起了广泛关注,大量的实验现象与细胞机制的研究成果已经使再可塑性的理论体系逐渐完善。尤其是近年来,人们发现再可塑性调节不仅可以影响突触可塑性,在个体水平上,再可塑性调节也可以提高动物的学习记忆能力,并且可以调控神经网络对特定信息的编码。这些研究成果不仅极大地丰富了再可塑性的理论体系,也为人们探究学习记忆功能开辟了新的道路。本文从以下三个方面对再可塑性调节的研究进展进行了概括与总结:(1)再可塑性的主要分子机制;(2)再可塑性对学习记忆功能的影响;(3)再可塑性领域的研究展望。     

慢性痛的皮层神经可塑性及其对治疗的启示

慢性痛疗效时常不够理想,使人们开始怀疑慢性痛患者大脑的功能或结构发生了病理性改变。脑成像研究表明,大脑功能和结构都存在明显的可塑性:从功能来看,慢性痛患者可能存在大脑网络功能状态失衡;从结构来看,患者大脑某些区域灰质密度明显减少。这些可塑性变化与慢性疼痛的存在及其治疗转归有可能存在密切联系。     

手术截断小鼠尾末端诱发的痛觉过敏和吗啡镇痛效应

手术截断小鼠尾末端可诱发长期性的痛觉过敏和吗啡镇痛效应变化。这种长期性的变化可能是由于中枢神经系统的神经可塑性变化引起的(从脊髓背角到皮层)。在截尾5周后,小鼠后肢和余下的尾端出现痛敏反应。低剂量吗啡可诱发热板的易化反应。这些可塑性变化能延长至5周,因此小鼠的截尾模型可以用于研究截肢后的中枢性长期性的可塑性变化。     

双语者大脑结构的可塑性

掌握一种以上的语言是人类的特殊能力,一般认为这种技能是大脑的功能发生可塑性改变,并非结构有所变化。然而,Mecheli及其同事提出了不同的看法,他们使用全脑无偏向性的客观技术——以体素为基础的形态测量方法（VBM）,来检测双语者大脑结构的可塑性,这种方法可以自动选择性地将灰质和白质区分开来。     

哺乳动物大脑中神经活动如何改变突触

大脑最基本性质是快速适应周围环境改变的能力,这主要是通过改变各个神经细胞之间的连接来实现的。有多种不同机制可以调节突触的强度,包括突触效率的稳态调节、突触增强和减弱的形态学表现以及钙在其中的作用。当开始了解这些突触改变的细胞生物学机制的时候,也应该考虑这种突触可塑性在完整大脑中的功能意义。因此,应用最新的成像手段来研究经验如何影响皮层环路中突触的改变,尤其是在体双光子显微技术可以在新皮层的单个神经元水平上研究形态和功能可塑性。这些实验将逐渐填补传统的细胞水平和系统水平研究之间的空白,并将有助于更全面充分地理解突触可塑性这种现象及其在皮层功能乃至动物行为中所起的作用。     

高级视皮层可塑性:物体和面孔知觉学习综述

复杂刺激的知觉学习是指由训练或经验引起的对物体或者面孔等复杂视觉刺激在知觉上长期稳定的改变,一般认为这反映了大脑高级视皮层的可塑性.对简单刺激知觉学习特性的研究已经揭示了低级视皮层的部分可塑性,但是复杂刺激知觉学习的神经机制目前仍存在争议.本文介绍了知觉学习的理论模型和实验证据,并重点探讨了复杂刺激如物体和面孔知觉学习的特性、神经机制及研究方法.该领域未来需要在复杂刺激知觉学习的持久性、面孔不同属性知觉学习的机制,以及复杂刺激知觉学习的理论模型方面做进一步研究.     

Short Term Integrative Meditation Improves Resting Alpha Activity and Stroop Performance

Our previous research showed that short term meditation training reduces the time to resolve conflict in the flanker task. Studies also show that resting alpha increases with long term meditation practice. The aim of this study is to determine whether short term meditation training both increases resting alpha activity and reduces the time to resolve conflict in the Stroop task and whether these two effects are related. Forty-three Chinese undergraduates were randomly assigned an experiment group given 5 days meditation training using integrative body-mind training (IBMT) and a relaxation training control. After training, only the IBMT group showed decreased conflict reaction time (RT), and increased resting mean alpha power. Moreover, the higher the enhancement of resting alpha power, the stronger the improvement of conflict RT. The results indicate that short term meditation diffusely enhances alpha and improves the ability to deal with conflict and moreover these two effects are positively related.     

Muscle morphological and strength adaptations to endurance vs. resistance training

Fascicle angle (FA) is suggested to increase as a result of fiber hypertrophy and furthermore to serve as the explanatory link in the discrepancy in the relative adaptations in the anatomical cross-sectional area (CSA) and fiber CSA after resistance training (RT). In contrast to RT, the effects of endurance training on FA are unclear. The purpose of this study was therefore to investigate and compare the longitudinal effects of either progressive endurance training (END, n = 7) or RT (n = 7) in young untrained men on FA, anatomical CSA, and fiber CSA. Muscle morphological measures included the assessment of vastus lateralis FA obtained by ultrasonography and anatomical CSA by magnetic resonance imaging of the thigh and fiber CSA deduced from histochemical analyses of biopsy samples from m. vastus lateralis. Functional performance measures included VO2max and maximal voluntary contraction (MVC). The RT produced increases in FA by 23 ± 8% (p < 0.01), anatomical CSA of the knee extensor muscles by 9 ± 3% (p = 0.001), and fiber CSA by 19 ± 7% (p < 0.05). RT increased knee extensor MVC by 20 ± 5% (p < 0.001). END increased VO2max by 10 ± 2% but did not evoke changes in FA, anatomical CSA, or in fiber CSA. In conclusion, the morphological changes induced by 10 weeks of RT support that FA does indeed serve as the explanatory link in the observed discrepancy between the changes in anatomical and fiber CSA. Contrarily, 10 weeks of endurance training did not induce changes in FA, but the lack of morphological changes from END indirectly support the fact that fiber hypertrophy and FA are interrelated.     

Grey and White Matter Changes across the Amyotrophic Lateral Sclerosis-Frontotemporal Dementia Continuum

There is increasing evidence that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a clinical, pathological and genetic continuum with patients of one disease exhibiting features of the other. Nevertheless, to date, the underlying grey matter and white matter changes across the ALS-FTD disease continuum have not been explored. In this study fifty-three participants with ALS (n = 10), ALS-FTD (n = 10) and behavioural variant FTD (bvFTD; n = 15) as well as controls (n = 18), underwent detailed clinical assessment plus structural imaging using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analysis of magnetic resonance brain imaging to examine grey and white matter differences and commonalities across the continuum. Importantly, patient groups were matched for age, education, gender and disease duration. VBM and DTI results showed that changes in the ALS group were confined mainly to the motor cortex and anterior cingulate as well as their underlying white matter tracts. ALS-FTD and bvFTD showed widespread grey matter and white matter changes involving frontal and temporal lobes. Extensive prefrontal cortex changes emerged as a marker for bvFTD compared to other subtypes, while ALS-FTD could be distinguished from ALS by additional temporal lobe grey and white matter changes. Finally, ALS could be mainly distinguished from the other two groups by corticospinal tract degeneration. The present study shows for the first time that FTD and ALS overlap in anterior cingulate, motor cortex and related white matter tract changes across the whole continuum. Nevertheless, frontal and temporal atrophy as well as corticospinal tract degeneration emerged as marker for subtype classification, which will inform future diagnosis and target disease management across the continuum.     

Comparison of the Relationship between Cerebral White Matter and Grey Matter in Normal Dogs and Dogs with Lateral Ventricular Enlargement

Large cerebral ventricles are a frequent finding in brains of dogs with brachycephalic skull conformation, in comparison with mesaticephalic dogs. It remains unclear whether oversized ventricles represent a normal variant or a pathological condition in brachycephalic dogs. There is a distinct relationship between white matter and grey matter in the cerebrum of all eutherian mammals. The aim of this study was to determine if this physiological proportion between white matter and grey matter of the forebrain still exists in brachycephalic dogs with oversized ventricles. The relative cerebral grey matter, white matter and cerebrospinal fluid volume in dogs were determined based on magnetic-resonance-imaging datasets using graphical software. In an analysis of covariance (ANCOVA) using body mass as the covariate, the adjusted means of the brain tissue volumes of two groups of dogs were compared. Group 1 included 37 mesaticephalic dogs of different sizes with no apparent changes in brain morphology, and subjectively normal ventricle size. Group 2 included 35 brachycephalic dogs in which subjectively enlarged cerebral ventricles were noted as an incidental finding in their magnetic-resonance-imaging examination. Whereas no significant different adjusted means of the grey matter could be determined, the group of brachycephalic dogs had significantly larger adjusted means of lateral cerebral ventricles and significantly less adjusted means of relative white matter volume. This indicates that brachycephalic dogs with subjective ventriculomegaly have less white matter, as expected based on their body weight and cerebral volume. Our study suggests that ventriculomegaly in brachycephalic dogs is not a normal variant of ventricular volume. Based on the changes in the relative proportion of WM and CSF volume, and the unchanged GM proportions in dogs with ventriculomegaly, we rather suggest that distension of the lateral ventricles might be the underlying cause of pressure related periventricular loss of white matter tissue, as occurs in internal hydrocephalus.     

Regional grey and white matter changes in heavy male smokers

Cigarette smoking is highly prevalent in the general population but the effects of chronic smoking on brain structures are still unclear. Previous studies have found mixed results regarding regional grey matter abnormalities in smokers. To characterize both grey and white matter changes in heavy male smokers, we investigated 16 heavy smokers and 16 matched healthy controls, using both univariate voxel-based morphometry (VBM) and multivariate pattern classification analysis. Compared with controls, heavy smokers exhibited smaller grey matter volume in cerebellum, as well as larger white matter volume in putamen, anterior and middle cingulate cortex. Further, the spatial patterns of grey matter or white matter both discriminated smokers from controls in these regions as well as in other brain regions. Our findings demonstrated volume abnormalities not only in the grey matter but also in the white matter in heavy male smokers. The multivariate analysis suggests that chronic smoking may be associated with volume alternations in broader brain regions than those identified in VBM analysis. These results may better our understanding of the neurobiological consequence of smoking and inform smoking treatment.     

Homosexual women have less grey matter in perirhinal cortex than heterosexual women

Is sexual orientation associated with structural differences in the brain? To address this question, 80 homosexual and heterosexual men and women (16 homosexual men and 15 homosexual women) underwent structural MRI. We used voxel-based morphometry to test for differences in grey matter concentration associated with gender and sexual orientation. Compared with heterosexual women, homosexual women displayed less grey matter bilaterally in the temporo-basal cortex, ventral cerebellum, and left ventral premotor cortex. The relative decrease in grey matter was most prominent in the left perirhinal cortex. The left perirhinal area also showed less grey matter in heterosexual men than in heterosexual women. Thus, in homosexual women, the perirhinal cortex grey matter displayed a more male-like structural pattern. This is in accordance with previous research that revealed signs of sex-atypical prenatal androgenization in homosexual women, but not in homosexual men. The relevance of the perirhinal area for high order multimodal (olfactory and visual) object, social, and sexual processing is discussed.     

Stress-Induced Grey Matter Loss Determined by MRI Is Primarily Due to Loss of Dendrites and Their Synapses

Stress, unaccompanied by signs of post-traumatic stress disorder, is known to decrease grey matter volume (GMV) in the anterior cingulate cortex (ACC) and hippocampus but not the amygdala in humans. We sought to determine if this was the case in stressed mice using high-resolution magnetic resonance imaging (MRI) and to identify the cellular constituents of the grey matter that quantitatively give rise to such changes. Stressed mice showed grey matter losses of 10 and 15 % in the ACC and hippocampus, respectively but not in the amygdala or the retrosplenial granular area (RSG). Concurrently, no changes in the number or volumes of the somas of neurons, astrocytes or oligodendrocytes were detected. A loss of synaptic spine density of up to 60 % occurred on different-order dendrites in the ACC and hippocampus (CA1) but not in the amygdala or RSG. The loss of spines was accompanied by decreases in cumulative dendritic length of neurons of over 40 % in the ACC and hippocampus (CA1) giving rise to decreases in volume of dendrites of 2.6 mm³ for the former and 0.6 mm³ for the latter, with no change in the amygdala or RSG. These values are similar to the MRI-determined loss of GMV following stress of 3.0 and 0.8 mm³ in ACC and hippocampus, respectively, with no changes in the amygdala or RSG. This quantitative study is the first to relate GMV changes in the cortex measured with MRI to volume changes in cellular constituents of the grey matter.     

Skill-Specific Changes in Somatosensory Nogo Potentials in Baseball Players

Athletic training is known to induce neuroplastic alterations in specific somatosensory circuits, which are reflected by changes in somatosensory evoked potentials and event-related potentials. The aim of this study was to clarify whether specific athletic training also affects somatosensory Nogo potentials related to the inhibition of movements. The Nogo potentials were recorded at nine cortical electrode positions (Fz, Cz, Pz, F3, F4, C3, C4, P3 and P4) in 12 baseball players (baseball group) and in 12 athletes in sports, such as track and field events and swimming, that do not require response inhibition, such as batting for training or performance (sports group). The Nogo potentials and Go/Nogo reaction times (Go/Nogo RTs) were measured under a somatosensory Go/Nogo paradigm in which subjects were instructed to rapidly push a button in response to stimulus presentation. The Nogo potentials were obtained by subtracting the Go trial from the Nogo trial. The peak Nogo-N2 was significantly shorter in the baseball group than that in the sports group. In addition, the amplitude of Nogo-N2 in the frontal area was significantly larger in the baseball group than that in the sports group. There was a significant positive correlation between the latency of Nogo-N2 and Go/Nogo RT. Moreover, there were significant correlations between the Go/Nogo RT and both the amplitude of Nogo-N2 and Nogo-P3 (i.e., amplitude of the Nogo-potentials increases with shorter RT). Specific athletic training regimens may induce neuroplastic alterations in sensorimotor inhibitory processes.     

Differential Grey Matter Changes in Sensorimotor Cortex Related to Exceptional Fine Motor Skills

Functional changes in sensorimotor representation occur in response to use and lesion throughout life. Emerging evidence suggests that functional changes are paralleled by respective macroscopic structural changes. In the present study we used voxel-based morphometry to investigate sensorimotor cortex in subjects with congenitally malformed upper extremities. We expected increased or decreased grey matter to parallel the enlarged or reduced functional representations we reported previously. More specifically, we expected decreased grey matter values in lateral sensorimotor cortex related to compromised hand function and increased grey matter values in medial sensorimotor cortex due to compensatory foot use. We found a medial cluster of grey matter increase in subjects with frequent, hand-like compensatory foot use. This increase was predominantly seen for lateral premotor, supplementary motor, and motor areas and only marginally involved somatosensory cortex. Contrary to our expectation, subjects with a reduced number of fingers, who had shown shrinkage of the functional hand representation previously, did not show decreased grey matter values within lateral sensorimotor cortex. Our data suggest that functional plastic changes in sensorimotor cortex can be associated with increases in grey matter but may also occur in otherwise macroscopically normal appearing grey matter volumes. Furthermore, macroscopic structural changes in motor and premotor areas may be observed without respective changes in somatosensory cortex.