织物纹理的简单视神经细胞感受野的选择特性

研究了织物纹理的简单视神经细胞感受野的选择特性。分别选择具有明显方向性和周期性以及周期性和方向性不显著的两类代表织物纹理为研究对象,采用基于独立分量分析的视觉模型估计出简单视觉细胞的感受野。通过对感受野兴奋区域重心、方向角和面积的分析,以有效表示感受野在位置、方向和空间频率的选择特性。基于织物纹理与自然纹理两类纹理的简单细胞感受野选择性比较实验显示,相比于自然纹理,织物纹理的简单细胞感受野单元中的兴奋区域在方向、位置和空间频率上具有更加显著的选择特性。实验结果表明,提出的简单视觉细胞感受野选择特性研究方法在一定程度上揭示了初级视皮层对织物纹理图像处理的神经机制,从视觉感知层面反映了织物纹理的视觉特性。

视神经细胞的功能及对视觉的影响

传统的观念认为柱状细胞只是在暗视觉条件下起作用。近年来的研究表明即使在亮度水平很高的条件下 ,柱状细胞对视觉功能都有着很大的影响 ,该文阐述了其对周边视觉 ,眩光感受 ,运动感受等方面的影响 ,并分析了其在实际照明中的应用。

人参皂苷Rg1治疗高糖损伤大鼠视神经细胞的机制研究:基于生物信息学分析

目的通过SwissTarget及PubMed数据库预测人参皂苷Rg1治疗高糖损伤大鼠视神经细胞的潜在靶点及作用机制。方法利用PubMed compound网站获取人参皂苷Rg1的分子结构式并于SwissTarget数据库进行Rg1治疗全部疾病的靶点预测,通过高糖损伤视神经相关PubMed数据库数据集GSE 27382分析视神经损伤患者与健康人员差异基因的表达情况,将SwissTarget数据库的预测结果与PubMed数据库分析结果进行集合,最终筛选Rg1治疗高糖损伤大鼠视神经细胞的潜在靶点IL-2、PTAFR、PSEN2、PSENEN、NCSTN、APH1A、PSEN1、APH1B、HSP90AA1,将获得的靶点进行KEGG及GO富集分析,明确相关的生物过程及分子功能、信号通路,将Notch/MAPK信号通路选定为机制研究的内容。镜下摘取饲养的16只Wistar大鼠双侧视神经,使用含新生胎牛血清的DMEM/F12培养基进行原代培养2周,经过形态学验证后,将细胞分为对照组、高糖损伤组(高糖DMEM/F12培养24 h)、Rg1治疗组(10μg·L^(-1) Rg1及高糖DMEM/F12同时培养24 h)及Notch1抑制剂组(10μg·L^(-1) Tangerintin及高糖DMEM/F12同时培养24 h)。采用CCK-8法检测不同组别大鼠视神经细胞培养24 h、48 h、72 h的增殖能力,采用免疫印迹法验证Notch/MAPK信号通路蛋白表达的变化。结果细胞增殖实验结果显示,与对照组相比,高糖损伤组大鼠视神经细胞培养24 h、48 h、72 h后吸光度均明显下降(均为P<0.05);与高糖损伤组相比,Rg1治疗组大鼠视神经细胞培养24 h、48 h、72 h后吸光度均增加(均为P<0.05)。免疫印记法结果显示,与对照组相比,高糖损伤组大鼠视神经细胞Notch1受体蛋白表达下降,MAPK、JNK、ERK1、P38蛋白表达均增加;而与高糖损伤组相比,Rg1治疗组和Notch1抑制剂组大鼠视神经细胞中Notch1受体蛋白表达均升高,MAPK、ERK1、JNK、P38蛋白表达均下降。结论人参皂苷Rg1通过激活Notch1受体影响Notch/MAPK信号通路,进而缓解高糖引起的大鼠视神经损伤。

视网膜神经细胞有序发生的研究现状

在发育神经生物学领域 ,视网膜神经细胞的发生是研究热点之一。先天性视网膜病变的发病机制、视网膜移植供体材料选择与病种相关性研究均与视网膜神经细胞的发生有密切关系。本文分别阐述视网膜神经细胞发生时间的判定方法、不同动物视网膜神经细胞发生的时空顺序及其共同规律 ,着重介绍视网膜神经节细胞的发生规律 ,并对神经细胞有序发生的分子机制作一综述。

氟西汀对单眼剥夺弱视大鼠视皮质神经细胞突触可塑性的影响及相关机制

目的探究氟西汀对单眼剥夺弱视大鼠视皮质神经细胞突触可塑性的影响与机制。方法60只SPF级雄性SD大鼠取10只为对照组,余50只构建单眼剥夺弱视大鼠模型。建模成功的50只大鼠依据随机数字表法分为阳性药组,模型组,低、中、高剂量组,每组10只。低、中、高剂量组分别腹腔注射5、10、20 mg/(kg·d)氟西汀;阳性药组灌胃左旋多巴80 mg/(kg·d);模型组、对照组腹腔注射等量生理盐水,各组给药28 d。检测各组大鼠P_(100)潜伏期、P_(100)幅值;观察各组大鼠视皮层神经元细胞突触超微结构变化;检测各组大鼠视皮层组织中ERK1/2、p-ERK1/2、CREB、p-CREB蛋白水平。结果模型组大鼠P_(100)潜伏期、突触间隙与突触致密厚度高于对照组,P_(100)幅值和视皮层组织p-ERK1/2/ERK1/2、p-CREB/CREB低于对照组,差异有统计学意义(P<0.05)。低、中、高剂量组大鼠P_(100)潜伏期、突触间隙与突触致密厚度低于模型组,P_(100)幅值和视皮层组织p-ERK1/2/ERK1/2、p-CREB/CREB高于模型组;中、高剂量组大鼠P_(100)潜伏期、突触间隙与突触致密厚度低于低剂量组,P_(100)幅值和视皮层组织p-ERK1/2/ERK1/2、p-CREB/CREB高于低剂量组;高剂量组大鼠P_(100)潜伏期、突触间隙与突触致密厚度低于中剂量组,P_(100)幅值和视皮层组织p-ERK1/2/ERK1/2、p-CREB/CREB高于中剂量组,差异有统计学意义(P<0.05)。与模型组比较,低、中、高剂量组大鼠视皮层神经元突触和髓鞘板层结构稍清晰。结论氟西汀能重塑单眼剥夺弱视大鼠视皮质神经细胞突触超微结构,激活视皮层结构可塑性,改善大鼠视觉功能,可能是通过激活ERK/CREB通路实现。

ZINC ATTENUATES AND EXACERBATES RETINAL NEURONAL DEATH DEPENDING ON CONCENTRATION

Retinal photoreceptors and the retinal pigment epithelium contains particularly high amount of free zinc. Free zinc is also associated with the neuronal retina but at lower amounts where it is thought to participate in a number of functions, including being a neuromodulator. In the studies conducted we now provide experimental evidence to show that zinc is a key mediator and modulator of neuronal death in the retina. For example, physio-

人造视网膜把光信号转化成神经信号

日本研究人员把林原生物化学研究所合成的一种光变电色素固定在聚乙烯薄膜上，并把这种薄膜放在尚未形成视细胞的鸡幼体视网膜上面，然后用光照射。结果发现，在鸡幼体视网膜视神经细胞中起信息传递作用的钙离子含量上升。

An intracellular study of pretectal influence on the optic tectum of the frog, Rana catesbeiana

Objective A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular recordings to demonstrate the unexpected complexity in synaptic mechanisms involved in the suppressive influences of pretecal stimulation on the tectal cells. Methods In the present study, we investigated the neuronal activity evoked by pretectal （Lpd/P） nuclei stimulation using intracellular recording technique. Results The pretectal stimulation mainly elicited two types of responses in the ipsilateral tectum： an excitatory postsynaptic potential （EPSP） followed by an inhibitory postsynaptic potential （IPSP） and a pure IPSP. The latter predominated in the tectal cells responding to pretectal stimulation. In a few cells, biphasic hyperpolarization appeared under stronger stimulus intensities. The spikes of tecto-pretectal projecting cells elicited by antidromical stimulation were recorded in the ipsilateral tectum, which revealed reciprocal connections between the tectum and particular pretectal nuclei. The synaptic natures underlying pretecto-tectal information transformation have also been demonstrated. EPSPs with short latencies were concluded to be monosynaptic. Most IPSPs were generated through polysynaptic paths, but monosynaptic IPSPs were also recorded in the tectum. Nearly 98% of impaled tectal cells （except for antidromically projecting cells） showed inhibitory responses to pretectal stimulation. Conclusion The results provide strong evidence that pretectal cells broadly inhibit tectal neurons as that has suggested by behavioral and extracellular recording studies.

ABC transporters,neural stem cells and neurogenesis - a different perspective

Stem cells intrigue. They have the ability to divide exponentially, recreate the stem cell compartment, as well as create differentiated cells to generate tissues. Therefore, they should be natural candidates to provide a renewable source of cells for transplantation applied in regenerative medicine. Stem cells have the capacity to generate specific tissues or even whole organs like the blood, heart, or bones. A subgroup of stem cells, the neural stem cells （NSCs）, is characterized as a self-renewing population that generates neurons and glia of the developing brain. They can be isolated, genetically manipulated and differentiated in vitro and reintroduced into a developing, adult or a pathologically altered central nervous system. NSCs have been considered for use in cell replacement therapies in various neurodegenerative diseases such as Parkinson＇s disease and Alzheimer＇s disease. Characterization of genes with tightly controlled expression patterns during differentiation represents an approach to understanding the regulation of stem cell commitment. The regulation of stem cell biology by the ATP-binding cassette （ABC） transporters has emerged as an important new field of investigation. As a major focus of stem cell research is in the manipulation of cells to enable differentiation into a targeted cell population; in this review, we discuss recent literatures on ABC transporters and stem cells, and propose an integrated view on the role of the ABC transporters, especially ABCA2, ABCA3, ABCB 1 and ABCG2, in NSCs＇ proliferation, differentiation and regulation, along with comparisons to that in hematopoietic and other stem cells.

Effects of Qingguang’an Granules on mitochondrial autophagy of retinal ganglion cells in rats with chronic ocular hypertension

Objective To investigate the effect and underlying mechanism of Qingguang’an Granules(青光安颗粒剂,QGAG)on mitochondrial autophagy(mitophagy)of retinal ganglion cells(RGCs)in rats with chronic ocular hypertension(COH).Methods Sixty Sprague Dawley(SD)rats,half males and half females,were randomly assigned to three groups:the control,model,and QGAG(2.5 g/kg)groups,with 20 rats in each group.Rats’model of COH was established by cauterizing episcleral veins in the model group and QGAG group.Three weeks after successful modeling,rats in the QGAG group were intra-gastrically administered with QGAG,while rats in the control group and the model group received an equal dose of normal saline.After three months of intragastric administration,intraocular pressure(IOP)of all rats was measured.The mitophagy was monitored by the immunofluorescence method,the mitochondrial membrane potential was measured using the JC-1 method,and the morphological changes of mitophagy in RGCs were observed by transmission electron microscopy.Meanwhile,rat RGCs were labeled using the fluorescent gold method,and RGCs density in each group was calculated.Moreover,RGCs apoptosis was observed by TdT-mediated dUTP Nick-End Labeling(TUNEL)assay.Finally,the expression levels of Parkin,optineurin,microtubule-associated protein 1 light chain 3-Ⅱ/microtubule-associated protein 1 light chain 3-Ⅰ(LC3-Ⅱ/LC3-Ⅰ),recombinant lysosomal associated membrane protein 1(LAMP1),and B-cell lymphoma-2(Bcl-2)in RGCs were determined by Western blot assay.The corresponding mRNAs were detected through quantitative real-time polymerase chain reaction(qRT-PCR).Results The QGAG reduced IOP in COH rats,and inhibited mitophagy and apoptosis of RGCs(P<0.05).Besides,the QGAG significantly increased the expression levels of Parkin and Bcl-2(P<0.05),and inhibited the expression levels of optineurin,LAMP1,and LC3-Ⅱ/LC3-Ⅰ(P<0.05)in RGCs of COH rats.Conclusion The QGAG can inhibit mitophagy in RGCs of COH rats and show a protective effect against optic nerve damage caused by glaucoma,which may be mediated through the mitophagy ubiquitination via the Parkin/PINK1-related pathway.

Proposal for a Reasonable Model of the Visual System： Principles of Clinical Neurosociology

This paper maintains that when photons enter the pupil and reach the Inner Limiting Membrane （ILM）, they are reflected onto a point or centroid of the vitreous body, which could be the lens, to be transmitted by the Muiller cells to the Retinal Pigment Epithelium （RPE） hexagonal cells, where an almost complete image is formed in each of them, overlapping with the adjacent images, to be carried subsequently by each of the ganglion cell axons to a place where the single image we are aware of is formed. This process calls for a high degree of control and coordination, which must be effected by the horizontal, amacrine, and interplexiform cells, gap junctions and the feedback provided from the V1 area to the Lateral Geniculate Nucleus （LGN）. But, as the ILM covers the optic disc but not the fovea, the latter must produce the blind spot and the rays reflected radially from the centroid must have the same centre as the Muller cells in order to be able to channel them to the RPE cells.

Retinal ganglion cells of high cytochrome oxidase activity in the rat

Retinal ganglion cells in the rat were studied using the heavy metal intensified oytochrome oxidase and horseradish peroxidase histochemieal methods. The results show that a population of large retinal ganglion cells was consistently observed with the eyto3hrome oxidase staining method in retinas of normal rats or rats which received unilateral thalamotomy at birrth. These oytochrome oxidase rich ganglion cells appeared to have large somata, 3-6 primary dendrites and extensive dendritic arbors, and are comparable to ganglion cells labeled by the wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). However, the morphological details of some of the cells revealed by the cytoahrome oxidase staining method are frequently better than those shown by the HRP histochemieal method. These results suggest that the mit03hondrial enzyme oytoohrome oxidase can be used as a simple but reliable marker for identifying and studying a population of retinal ganglion cells with high metabolie rate in the rat.

Hub Genes of Astrocyte Involved in Glaucoma with Ocular Hypertension by Integrated Bioinformatics Analysis

This study was conducted to elucidate the potential key candidate genes and pathways in role of astrocyte involved in glaucoma with ocular hypertension.Methods Expression profiles GSE2378 and GSE758 including 27 reactive optic nerve head astrocytes(ONHAs)by hypertensions and 26 normal controls,were integrated and deeply analyzed.Differentially expressed genes(DEGs)were sorted and candidate genes and pathways enrichment were analyzed.DEGs-associated protein-protein interaction network(PPI)was performed.Results A total of 119 consistently expressed genes were identified from 281 commonly changed DEGs,including 68 up-regulated genes and 51 down-regulated genes.PPI network complex filtered 75 DEGs(43 up-regulated and 32 down-regulated genes)of the 119 consistently altered DEGs and developed 117 edges,and 10 hub genes were identified.The most significant 3 modules were filtered from PPI,pathway enrichment analysis showed that module 1 was associated with extracellular exosome.Module 2 was mainly associated with antibody-dependent cellular cytotoxicity(ADCC)and module 3 was mainly associated with Hippo signaling pathway.Conclusion Taken above,using integrated bioinformatical analysis,we have identified DEGs candidate genes and pathways in role of astrocyte involved in glaucoma with ocular hypertension,which could improve our understanding of the cause and underlying molecular events,and these candidate genes and pathways could be therapeutic targets for glaucoma.

Robustness Design for CNN Templates with Performance of Extracting Closed Domain

The cellular neural/nonlinear network （CNN） is a powerful tool for image and video signal processing, robotic and biological visions. This paper introduces a kind of CNNs with performance of extracting closed domains in binary images, and gives a general method for designing templates of such a kind of CNNs. One theorem provides parameter inequalities for determining parameter intervals for implementing prescribed image processing functions, respectively. Examples for extracting closed domains in binary scale images are given.

Noradrenaline as a putative neurotransmitter mediating hypotension-induced Fos-like immunoreactivity inthe supraoptic nucleus of the rat

Hemorrhage or hypotension induces extensive Foslike immunoreactivity in the magnocellular neurosecretory cells in the supraoptic nucleus of the hypothalamus in rat, especially in the vasopressin neurons. The present study was to explore the neurotransmitter mediating this effect. Microinfusion of the alpha-adrenergic blocker into the supraoptic nucleus reduced the hypotension-induced Fos, whereas beta-antagonist did not affect it significantly. Alpha1- and alpha2-antagonist, prazosin and yohimbine,both reduced the Fos-positive cell counts. However, the effective dosage of yohimbine was much larger. Alpha1-agonist, methoxamine, induced abundant Fos-like immnnoreactivity in the vasopressin cells in this nucleus,while beta-and alpha2-agonist did not elicit such effect.Administration of the noradrenergic re-uptake inhibitor,desipramine, to this nucleus to locally accumulate the spontaneously released noradrenaline from the nerve terminals also induced Fos expression, mostly in the vasopressin cells.

小心弱视找上宝宝

6个月的晨晨吃奶时脑袋总喜欢偏向一侧，一帮他转头，她就大哭不吃了；1岁的琪琪在室外的阳光下总是眯着眼睛，不敢看东西；2岁的天天下楼梯时总是踩不准楼梯位置，为此没少摔跤。医生为这三个宝宝做出了相同的诊断：弱视。

Protection of retinal ganglion cells against glaucomatous neuropathy by neurotrophin-producing,genetically modified neural progenitor cells in a rat model

OBJECTIVE: To investigate in vivo survival of retinal ganglion cells (RGCs) after partial blockage of optic nerve (ON) axoplasmic flow by sub-retinal space or vitreous cavity injection of brain-derived neural factor (BDNF) produced by genetically modified neural progenitor cells (NPCs). METHODS: Adult Sprague-Dawley (SD) rat RGCs were labeled with granular blue (GB) applied to their main targets in the brain. Seven days later, the left ON was intra-obitally crushed with a 40 g power forceps to partially block ON axoplasmic flow. Animals were randomized to three groups. The left eye of each rat received a sham injection, NPCs injection or an injection of genetically modified neural progenitors producing BDNF (BDNF-NPCs). Seven, 15 and 30 days after ON crush, retinas were examined under a fluorescence microscope. By calculating and comparing the average RGCs densities and RGC apoptosis density, RGC survival was estimated and the neuro-protective effect of transplanted cells was evaluated. RESULTS: Seven, 15 and 30 days after crush, in the intra-vitreous injection group, mean RGC densities had decreased to 1885 +/- 68, 1562 +/- 20, 1380 +/- 7 and 1837 +/- 46, 1561 +/- 58, 1370 +/- 16, respectively with sham injection or neural progenitors injection. However, RGCs density in the groups treated with intra-vitreous injection of BDNF-NPC was 2101 +/- 15, 1809 +/- 19 and 1625 +/- 34. Similar results were found in groups after sub-retinal injection. Higher densities were observed in groups treated with BDNF-NPCs. There were statistically significant differences among groups through nonparametric tests followed by the Mann-Whitely test. RGC apoptosis density in BDNF-NPC at each follow-up time was less than in other groups. CONCLUSIONS: A continuous supply of neurotrophic factors by the injection of genetically modified neural progenitors presents a highly effective approach to counteract optic neuropathy and RGC degeneration after partial ON axoplasmic flow blockage.

Pro-protein convertase-2/carboxypeptidase-E mediated neuropeptide processing of RGC-5 cell after in vitro ischemia

Objective To observe the change of the neuropeptide pro-protein processing system in the ischemic retina ganglion cell-5(RGC-5) cells,pro-protein convertase-2(PC2),carboxypeptidase-E(CPE) and preproneuropeptide Y(preproNPY) protein levels in the ischemic RGC-5 cells and conditioned medium were analyzed. Methods The RGC-5 cell was differentiated in 0.1 μmol/L staurosporine for 24 h and then stressed by different doses of oxygen and glucose deprivation(OGD). The acute or chronic OGD-induced cell death rates w...

Diabetic retinopathy: recent advances towards understanding neurodegeneration and vision loss

Diabetic retinopathy （DR） is one of the most common retinal diseases world-wide. It has a complex pathology that involves the vasculature of the inner retina and breakdown of the blood-retinal barrier. Extensive research has determined that DR is not only a vascular disease but also has a neurodegenerative component and that essentially all types of ceils in the retina are affected, leading to chronic loss of visual function. A great deal of work using animal models of DR has established the loss of neurons and pathology of other cell types, including supporting glial cells. There has also been an increased emphasis on measuring retinal function in the models, as well as further validation and extension of the animal studies by clinical and translational research. This article will attempt to summarize the more recent developments in research towards understanding the complexities of retinal neurodegeneration and functional vision loss in DR.