利用VSV标记具有特定投射的特异类型神经元的精细结构

神经元是构成神经系统的基本单位之一,对其精细形态结构的研究是了解神经网络构筑和信息处理方式的基础,然而目前缺乏能够标记具有特定投射特征的特异类型神经元精细结构的有效方法.在糖蛋白基因缺失的水泡性口炎病毒（VSV）毒株基础上突变其核蛋白,我们获得了重组病毒VSV-△G-NR7A-EGFP,并发现该病毒在一定窗口期内可实现神经元形态的快速高亮度标记;我们进一步在此基础上构建了VSV-△G-EnvA-NR7A-EGFP病毒,并基于特定的转基因动物及辅助病毒rAAV-EF1α-Dio-Bfp-Tva,通过控制注射位点,分别实现了有NAc-LH投射特异性的D2R神经元和VTA-NAc投射特异性的多巴胺神经元的标记,展示了一种可用于稀疏、高亮地标记具有特定投射特征的特异类型神经元精细结构的新方法.     

An AIE‐Based Probe for Rapid and Ultrasensitive Imaging of Plasma Membranes in Biosystems

The abnormality of the plasma membrane (PM) is an important biomarker for cell status and many diseases. Hence, visualizing the PM, especially in complex systems, is an emerging field in the life sciences, especially in low‐resource settings. Herein, we developed a water‐soluble PM‐specific probe utilizing electrostatic and hydrophobic interaction strategies with aggregation‐induced emission as the signal output. The probe could image the PM with many advanced features (wash‐free, ultrafast staining process, excellent PM specificity, and good biocompatibility), which were demonstrated by the PM imaging of neurons. The probe allowed for the first time the imaging of erythrocytes in the complex brain environment through a fluorescence‐based method. Moreover, the PM of the epidermal and partial view of the eyeball structure of live zebrafish are also revealed.     

A New Model of Coupled Hindmarsh-Rose Neurons

A new model of two coupled neurons is presented by the partly di?usive HindmarshRose equations. The solution semi?ow exhibits globally absorbing characteristics. As the main result, the self-synchronization of the coupled neurons at a uniform rate is proved, which can be extended to complex neuronal networks.     

Effect of channel block on the collective spiking activity of coupled stochastic Hodgkin-Huxley neurons

Toxins, such as tetraethylammonium (TEA) and tetrodotoxin (TTX), can make potassium or sodium ion channels poisoned, respectively, and hence reduce the number of working ion channels and lead to the diminishment of conductance. In this paper, we have studied by numerical simulations the effects of sodium and potassium ion channel poisoning on the collective spiking activity of an array of coupled stochastic Hodgkin-Huxley (HH) neurons. It is found for a given number of neurons sodium or potas- sium ion channel block can either enhance or reduce the collective spiking regularity, depending on the membrane patch size. For a given smaller or larger patch size, potassium and sodium ion channel block can reduce or enhance the collective spiking regularity, but they have different patch size ranges for the transformation. This result shows that sodium or potassium ion channel block might have dif- ferent effects on the collective spiking activity in coupled HH neurons from the effects for a single neuron, which represents the interplay among the diminishment of maximal conductance and the in- crease of channel noise strength due to the channel blocks, as well as the bi-directional coupling be- tween the neurons.     

THE PROPERTY OF PERIPHERAL INPUT OF PROJECTION NEURONS IN THE SPINAL CORD DORSAL HORN

Antidromic and orthodromic responses of the projection neurons in the dorsal horn ofthe spinal cord have been recorded by a glass microelectrode in anesthetized and paralyz-ed cats. Furthermore, the effect of cervical segment antidromic stimulation to orthodromicresponse of the projection neurons has been observed by way of conditioning-test stimulation. Among all the spinocervical tract neurons (SCT), the dorsal column postsynaptic neu-rons (DCPS) and the spinocervical tract-dorsal column postsynaptic neurons (SCT-DCPS),which were identified by cervical segment antidromic stimulation, 46% are low-thresholdmechanoreceptive (LTM) and 54% are wide-dynamic-range (WDR) neurons. Most LTMneurons can evoke the same response to both 10 times (10 T) and 50 times (50 T) the thresh-old stimulation on the peroneal nerve. Most WDR neurons to 50 T intensity stimulation arestronger than the 10 T stimulation. Under the antidromic-cervical segment conditioningstimulation, the amount of orthodromic-discharging in most WD     

高等学校学费标准的数学模型

依据国家统计局等权威机构提供的数据．对影响高校学费的经济、非经济指标和各高校学费的原始统计数据进行分析．得出较为合理的结论。对所得各模型进行评价．且其结果与高校学费现状基本吻合。     

诱导肿瘤细胞HeLa为多能性干细胞的研究

将携带4种转录因子的逆转录病毒共同感染HeLa细胞,感染后的细胞铺到滋养层细胞MEF上培养,细胞长出类似胚胎干细胞的克隆团,这种克隆团可以扩增,并进一步诱导分化为神经元,同时免疫荧光检测细胞分化不同天数后Pax6,Sox1和βⅢ-tubulin的表达.结果表明,肿瘤细胞HeLa在Oct4、Sox2、c-Myc、Klf4等4种转录因子的作用下成功重编程为多能干细胞,同时可进一步分化为神经元.     

The effects of rises in external K+ on the hyperpolarization-activated cation current Ih in rat dorsal root ganglion neurons

The effects of rises in external K⁺ (K_ext) were examined on the hyperpolarization-activated cation current (I _h) in rat dorsal root ganglion neurons using the whole-cell patch clamp technique. The results showed that K_ext increased I _h in a certain concentration and voltage-dependent manner. At the basal K_ext level (4 mmol/L), I _h had a maximal amplitude of 1085 ± 340 pA which was enhanced by ∼45% and ∼92% at 8 and 16 mmol/L K_ext, respectively. The midpoint activation voltage was significantly shifted from −98 mV in the hyperpolarizing direction by 8 and 12 mV at 8 and 16 mmol/L K_ext, respectively with alteration of the activation course of I _h. The short time constants of activation became longer with the increasing amplitude of the command potential upon rises in K_ext. The long time constants became shorter. The reversal potentials were shifted in the positive direction without significant alterations upon rises in K_ext. According to the functional role of I _h, K_ext increased I _h, resulting in an enhanced neuronal excitability, which might produce activation potential abnormality and perhaps neuropathic pain involved. Supported by the University of Science and Technology Foundation of Shanxi Province (Grant No. 200713010)     

面向匹配决策问题的漏整合神经元稀疏ESN网络

为了对匹配决策问题进行建模与预测,提出了一种具有更多神经生理学特征的稀疏回声状态网络(ESN),并基于在线监督学习方法对网络进行训练.为了评估网络的匹配决策性能,设计了三组测试数据集对网络性能进行测试,并提出了一种基于网络期望输出与实际输出序列最大相关系数的评价方法.仿真结果表明,新模型只需要较少的训练时间即可获得较好的决策性能,且对发放时间间隔、平移和网络噪声具有较好的鲁棒性.