菟丝子提取物对小脑中Bcl-2和Bax蛋白表达的影响

利用免疫组织化学超敏SP法检测SD大鼠摘除卵巢前后及菟丝子提取物治疗后小脑中Bcl-2和Bax蛋白表达的变化,探讨菟丝子提取物对大鼠小脑皮质和深层核团中Bcl-2和Bax蛋白表达的影响.结果,摘除双侧卵巢,小脑皮层及小脑深层核团中Bax阳性细胞数及其表达强度不同程度上升,而Bcl-2阳性细胞数及其表达强度不同程度降低;菟丝子提取物治疗后,Bax和Bcl-2的表达不同程度地恢复.结论:中药菟丝子提取物能够不同程度地下调小脑皮层及小脑深层核团中Bax蛋白的表达,上调Bcl-2蛋白的表达,从而对小脑神经元具有保护作用.     

雌激素和菟丝子提取物对大鼠小脑中Bcl-2和Bax蛋白表达的影响

利用免疫组织化学超敏SP法检测SD大鼠摘除卵巢再用17β-雌二醇和中药菟丝子提取物治疗后小脑中Bcl-2和Bax蛋白表达的变化.结果,摘除双侧卵巢,小脑皮质及深层核团中Bcl-2表达不同程度降低,而Bax的表达出现不同程度的上升;给予外源性雌激素及菟丝子提取物治疗后,两种蛋白的比例基本恢复正常,而且两者之间差异不显著.结果表明,雌激素和中药菟丝子提取物都能够不同程度地下调小脑皮质及小脑深层核团中Bax蛋白的表达,上调Bcl-2蛋白的表达,从而对小脑神经元具有保护作用,中药菟丝子提取物可以部分代替雌激素抑制和延缓神经元凋亡.     

小脑经颅直流电刺激技术提升运动表现的应用

小脑是脑皮层下的一个重要运动调节中枢,它与大脑不同皮层区域在解剖和功能上紧密连接,配合大脑皮层完成机体的运动功能和运动学习。经颅直流电刺激(transcranial direct current stimulation, tDCS)是一种非侵入性的脑刺激技术,通过电极将微弱的电流作用于小脑能有效地提升皮层脊髓兴奋性和调控小脑与大脑皮层间的功能连接。本文系统梳理近20年国内外关于tDCS刺激小脑对提升人类运动表现影响的相关文献,研究结果表明tDCS刺激小脑可以改善人体的运动表现,如姿势控制、运动适应与运动学习、肌肉力量表现等。然而,tDCS刺激小脑的生理机制和刺激强度、刺激时间、刺激时间间隔等参数的选择有待进一步研究。未来的体育科学研究中,如何将tDCS刺激小脑的技术应用于运动训练,帮助运动员突破现有的运动能力仍有待深入探究。     

钙激活的大电导钾离子通道在成年斑胸草雀脑中的分布

BK 通道，即钙离子激活的大电导钾离子通道，它通过产生快速的后超极化（fA HP）来控制动作电位的持续时间、发放频率。为研究BK通道在鸣禽鸣唱学习中的作用提供形态学依据，用免疫组化法观察了BK通道在成年雄性斑胸草雀脑中的分布。证实了其在端脑、基底节纹状体、中脑、小脑等脑区都有广泛的表达，其中 RA、HVC、LM AN、X区、DM 等与鸣唱系统相关的核团都有显著的表达。这暗示了BK通道可能与鸣禽鸣唱信息整合、听觉反馈、鸣曲可塑性和稳定性以及呼吸调节都有密不可分的联系。     

大鼠前庭核群亚核界定及其投射联系

前庭系统是脊椎动物中高度保守的感觉系统 ,对保持身体的空间位置、姿势平衡 ,调节肌紧张及协调眼球运动、自主神经活动的调节等起着重要作用 .前庭神经核是前庭传入的初级中枢 ,与中枢的很多核团和区域有传入、传出联系 .简述了近年来大鼠前庭核群在分区及其纤维联系等形态学上的研究进展     

大鼠前庭核群亚核界定及其投影联系

前庭系统是脊椎动物中高度保守的感觉系统，对保持身体的空间位置、姿势平衡，调节肌紧张及协调眼球运动、自主神经活动的调节等起着重要作用。前庭神经核是前庭传入的初级中枢，与中枢的很多核团和区域有传入，传出联系，简述了近年来大鼠前庭核群在分区及其纤维联系等形态学上的研究进展。     

一例多次脑卒中后排尿障碍间歇导尿的护理

脑出血或栓塞后,受累血管的远端可发生程度不等的梗死灶。研究显示控制逼尿肌和尿道外括约肌的神经传导束与支配躯体感觉和运动的神经行走途径几乎相同,因此常同时受到损害,大脑中有许多参与排尿控制的神经核团,如基底节、小脑、苍白球、纹状体、丘脑等,当上述神经通路或核团受到损害时病人除有特殊的意识、感觉运动功能障碍及原发性疾病的临床表现外,常有排尿功能紊乱。     

鸣禽前脑鸣啭控制核团内胆碱能神经元的分布

高级发声中枢（HVC）和古纹状体粗核（RA）是位于鸣禽前脑的两个主要鸣啭控制核团，以中国北方地区常见的两种鸣禽栗鹂（Emberiza rutila)和燕雀（Fingilla montifringilla）为材料，应用免疫组化方法，对两种鸣禽HVC和RA内胆碱能神经元的胞体大小和密度进行了观察、发现ChAT样免疫反应具有性别差异。这一结果提示胆碱能神经元可能在鸣啭的产生和学习过程中发挥着重要的作用。     

锡嘴雀延脑发声中枢注入HRP对上位脑细胞标记的研究初报

经我们对40例锡嘴雀(♀30、♂10)实验结果进一步证明了 RA 核团是大脑控制调节低位发声中枢引起发声运动的主要中枢之一。它发出的下行性的传出神经向 IM 核呈双侧性投射,并有明显的左侧优势。中脑的背中核(DM)核是 ICO 核团分化的一部分,它也是中脑控制发声的主要核团之一,除此之外,还发现了原纹状体腹部外侧区,LAV 区,在发声中也具有一定的调节、控制作用。     

大鼠前庭脊核经脑桥核接替向旁绒球的间接投射

探讨大鼠前庭脊核经脑桥核接替后向小脑旁绒球投射的间接通路,为揭示眼平稳跟踪运动的调控机制提供形态学基础.应用顺、逆行追踪结合偏离垂直轴旋转刺激激发脑内相关神经元Fos表达的方法,观察前庭脊核向脑桥核投射的顺行标记纤维与脑桥核内向小脑旁绒球投射的神经元是否有重叠.在脑桥外侧核发现前庭脊核投射来的纤维及终末与Fos/荧光金双重标记细胞有重叠.大鼠脑内存在前庭脊核经脑桥外侧核中继后投射至小脑旁绒球的间接通路.该通路有传递直线变速运动信号的作用,可能是眼平稳跟踪运动的调控途径之一.     

Multiple dynamic representations in the motor cortex during sensorimotor learning

The mechanisms linking sensation and action during learning are poorly understood. Layer 2/3 neurons in the motor cortex might participate in sensorimotor integration and learning; they receive input from sensory cortex and excite deep layer neurons, which control movement. Here we imaged activity in the same set of layer 2/3 neurons in the motor cortex over weeks, while mice learned to detect objects with their whiskers and report detection with licking. Spatially intermingled neurons represented sensory (touch) and motor behaviours (whisker movements and licking). With learning, the population-level representation of task-related licking strengthened. In trained mice, population-level representations were redundant and stable, despite dynamism of single-neuron representations. The activity of a subpopulation of neurons was consistent with touch driving licking behaviour. Our results suggest that ensembles of motor cortex neurons couple sensory input to multiple, related motor programs during learning.     

Neural population dynamics during reaching

Most theories of motor cortex have assumed that neural activity represents movement parameters. This view derives from what is known about primary visual cortex, where neural activity represents patterns of light. Yet it is unclear how well the analogy between motor and visual cortex holds. Single-neuron responses in motor cortex are complex, and there is marked disagreement regarding which movement parameters are represented. A better analogy might be with other motor systems, where a common principle is rhythmic neural activity. Here we find that motor cortex responses during reaching contain a brief but strong oscillatory component, something quite unexpected for a non-periodic behaviour. Oscillation amplitude and phase followed naturally from the preparatory state, suggesting a mechanistic role for preparatory neural activity. These results demonstrate an unexpected yet surprisingly simple structure in the population response. This underlying structure explains many of the confusing features of individual neural responses.     

Corticostriatal plasticity is necessary for learning intentional neuroprosthetic skills

The ability to learn new skills and perfect them with practice applies not only to physical skills but also to abstract skills, like motor planning or neuroprosthetic actions. Although plasticity in corticostriatal circuits has been implicated in learning physical skills, it remains unclear if similar circuits or processes are required for abstract skill learning. Here we use a novel behavioural task in rodents to investigate the role of corticostriatal plasticity in abstract skill learning. Rodents learned to control the pitch of an auditory cursor to reach one of two targets by modulating activity in primary motor cortex irrespective of physical movement. Degradation of the relation between action and outcome, as well as sensory-specific devaluation and omission tests, demonstrate that these learned neuroprosthetic actions are intentional and goal-directed, rather than habitual. Striatal neurons change their activity with learning, with more neurons modulating their activity in relation to target-reaching as learning progresses. Concomitantly, strong relations between the activity of neurons in motor cortex and the striatum emerge. Specific deletion of striatal NMDA receptors impairs the development of this corticostriatal plasticity, and disrupts the ability to learn neuroprosthetic skills. These results suggest that corticostriatal plasticity is necessary for abstract skill learning, and that neuroprosthetic movements capitalize on the neural circuitry involved in natural motor learning.     

Cortical ensemble activity increasingly predicts behaviour outcomes during learning of a motor task

When an animal learns to make movements in response to different stimuli, changes in activity in the motor cortex seem to accompany and underlie this learning. The precise nature of modifications in cortical motor areas during the initial stages of motor learning, however, is largely unknown. Here we address this issue by chronically recording from neuronal ensembles located in the rat motor cortex, throughout the period required for rats to learn a reaction-time task. Motor learning was demonstrated by a decrease in the variance of the rats' reaction times and an increase in the time the animals were able to wait for a trigger stimulus. These behavioural changes were correlated with a significant increase in our ability to predict the correct or incorrect outcome of single trials based on three measures of neuronal ensemble activity: average firing rate, temporal patterns of firing, and correlated firing. This increase in prediction indicates that an association between sensory cues and movement emerged in the motor cortex as the task was learned. Such modifications in cortical ensemble activity may be critical for the initial learning of motor tasks.     

Recurrent network activity drives striatal synaptogenesis

Neural activity during development critically shapes postnatal wiring of the mammalian brain. This is best illustrated by the sensory systems, in which the patterned feed-forward excitation provided by sensory organs and experience drives the formation of mature topographic circuits capable of extracting specific features of sensory stimuli. In contrast, little is known about the role of early activity in the development of the basal ganglia, a phylogenetically ancient group of nuclei fundamentally important for complex motor action and reward-based learning. These nuclei lack direct sensory input and are only loosely topographically organized, forming interlocking feed-forward and feed-back inhibitory circuits without laminar structure. Here we use transgenic mice and viral gene transfer methods to modulate neurotransmitter release and neuronal activity in vivo in the developing striatum. We find that the balance of activity between the two inhibitory and antagonist pathways in the striatum regulates excitatory innervation of the basal ganglia during development. These effects indicate that the propagation of activity through a multi-stage network regulates the wiring of the basal ganglia, revealing an important role of positive feedback in driving network maturation.     

MW-DLA:a dynamic bit width deep learning accelerator

Deep learning algorithms are the basis of many artificial intelligence applications. Those algorithms are both computationally intensive and memory intensive, making them difficult to deploy on embedded systems. Thus various deep learning accelerators(DLAs) are proposed and applied to achieve better performance and lower power consumption. However, most deep learning accelerators are unable to support multiple data formats. This research proposes the MW-DLA, a deep learning accelerator supporting dynamic configurable data-width. This work analyzes the data distribution of different data types in different layers and trains a typical network with per-layer representation. As a result, the proposed MW-DLA achieves 2 X performance and more than 50% memory requirement for AlexNet with less than 5.77% area overhead.     

Primate spinal interneurons show pre-movement instructed delay activity.

Preparatory changes in neural activity before the execution of a movement have been documented in tasks that involve an instructed delay period (an interval between a transient instruction cue and a subsequently triggered movement). Such preparatory activity occurs in many motor centres in the brain, including the primary motor cortex, premotor cortex, supplementary motor area and basal ganglia. Activity during the instructed delay period reflects movement planning, as it correlates with parameters of the cue and the subsequent movement (such as direction and extent), although it occurs well before muscle activity. How such delay-period activity shapes the ensuing motor action remains unknown. Here we show that spinal interneurons also exhibit early pre-movement delay activity that often differs from their responses during the subsequent muscle activity. This delay activity resembles the set-related activity found in various supraspinal areas, indicating that movement preparation may occur simultaneously over widely distributed regions, including spinal levels. Our results also suggest that two processes occur in the spinal circuitry during this delay period: the motor network is primed with rate changes in the same direction as subsequent movement-related activity; and a superimposed global inhibition suppresses the expression of this activity in muscles.     

基于深度学习的面部表情识别方法综述

人脸表情识别就是让计算机按照人类的思维理解表情,是人机交互的重要组成,然而随着深度学习的迅速发展,深度学习技术在人脸表情领域的研究也成为研究热点,所以对深度学习技术在表情识别中的应用及取得的成果进行分析。首先总结了几种常用表情数据集;然后从特征提取和特征分类两方面对基于深度学习的表情识别方法进行了分类,并从网络改进方面分析了基于深度学习的表情识别中的几种网络改进方法;最后阐述了表情识别这一领域中面临的挑战和未来发展。     

Long-term motor cortex plasticity induced by an electronic neural implant

It has been proposed that the efficacy of neuronal connections is strengthened when there is a persistent causal relationship between presynaptic and postsynaptic activity. Such activity-dependent plasticity may underlie the reorganization of cortical representations during learning, although direct in vivo evidence is lacking. Here we show that stable reorganization of motor output can be induced by an artificial connection between two sites in the motor cortex of freely behaving primates. An autonomously operating electronic implant used action potentials recorded on one electrode to trigger electrical stimuli delivered at another location. Over one or more days of continuous operation, the output evoked from the recording site shifted to resemble the output from the corresponding stimulation site, in a manner consistent with the potentiation of synaptic connections between the artificially synchronized populations of neurons. Changes persisted in some cases for more than one week, whereas the output from sites not incorporated in the connection was unaffected. This method for inducing functional reorganization in vivo by using physiologically derived stimulus trains may have practical application in neurorehabilitation after injury.