雏鸡中脑视顶盖中央灰质层细胞构筑研究

为了进一步阐明鸟类视觉通路的结构特征,本试验用尼氏体染色法、Golgi-CoxⅡ法及羰花青荧光染料DiI逆行神经标记3种方法对雏鸡视顶盖的中央灰质层(Stratum griseum centrale,SGC)细胞形态特征进行了观察和统计分析。结果表明:视顶盖SGC层背侧的厚度小于腹侧和外侧。SGC层细胞以大、中型细胞为主,多具有三角形、多边形及纺锤形的胞体。在高尔基镀银法(Golgi-CoxⅡ)染色和DiI逆行神经标记法标记出的细胞中,其树突清晰可见。三角形及纺锤形的细胞多从胞体发出2~3支主树突,树突野较大;多边形和少数三角形的细胞由胞体发出多支树突,树突野较小。     

雏鸡中脑视顶盖I层细胞构筑研究

为进一步阐明鸟类视觉通路的结构特征,试验采用Golgi-Cox法,灌流固定后尼氏体(Nissl bodies)染色和羰花青荧光染料DiI(1,1-’dioctadecyl-3,3,3’,3-t’etramethylindocarbo-cyanine perchlorate)逆向神经标记技术,对雏鸡视顶盖I层的厚度和该层的细胞形态、大小进行了观察研究和数理统计。结果表明,I层细胞多数呈梭形,还有少数呈圆形、椭圆形、锥形、三角形和不规则形状等。I层外侧部较背侧部和腹侧部厚。按照胞体面积大小将细胞分为4类:巨细胞、大细胞、中细胞和小细胞,I层背侧、腹侧和外侧以巨细胞最少,其中背侧、腹侧以小细胞为主,外侧以中细胞数量最多。I细胞具有2~6个主树突,其中有2个主树突的细胞最多(60.7%,n=128)。     

雏鸡中脑视顶盖Ⅰ层细胞构筑研究

为进一步阐明鸟类视觉通路的结构特征, 试验采用Golgi-Cox法, 灌流固定后尼氏体(Nissl bodies)染色和羰花青荧光染料DiⅠ(1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbo-cyanine perchlorate)逆向神经标记技术,对雏鸡视顶盖Ⅰ层的厚度和该层的细胞形态、大小进行了观察研究和数理统计.结果表明,Ⅰ层细胞多数呈梭形,还有少数呈圆形、椭圆形、锥形、三角形和不规则形状等.Ⅰ层外侧部较背侧部和腹侧部厚.按照胞体面积大小将细胞分为4类:巨细胞、大细胞、中细胞和小细胞,Ⅰ层背侧、腹侧和外侧以巨细胞最少,其中背侧、腹侧以小细胞为主,外侧以中细胞数量最多.Ⅰ细胞具有2～6个主树突,其中有2个主树突的细胞最多(60.7%, n=128).     

用细胞内注射法观察雏鸡投射向圆核的视顶盖SGC神经元形态

为了进一步了解鸟类投射向圆核的视顶盖中央灰质层(SGC)神经元的形态特征,向雏鸡圆核内注射快蓝(Fast blue,FB)逆向荧光标记视顶盖SGC神经元,84h后灌流固定,制作300μm厚的中脑振动切片,荧光显微镜下,通过显微操作系统向FB标记的SGC神经元内微电泳法注入荧光染料荧光黄(Lucifer yellow,LY)。结果显示,此法可观察到完整的投射向圆核的SGC神经元胞体和突起。与其它标记法相比,LY细胞内注射法可以标记单一神经元,不会被周围细胞的纤维干扰,是一种研究中枢神经系统神经元间投射关系及其起源细胞的好方法。     

IFN-γ在大鼠胸段脊髓内的分布

为进一步探讨免疫 -神经 -内分泌三大系统之间的关系 ,用免疫组织化学 SP法 ,对大鼠胸段脊髓内 IFN-γ样免疫反应产物的分布进行了研究。结果表明 ,IFN-γ样免疫反应产物广泛分布于胸段脊髓各板层。其中背角 、 、 层 ,胸髓中间带外侧核 ,腹角 层内可见到较高密度的阳性胞体和树突。中间带和腹角内的阳性胞体的树突还伸向外侧索和腹索 ,有时可达脊髓边缘     

Orexin A在鹌鹑间脑内定位分布的SABC法研究

采用免疫组织化学SABC法,研究orexin A在鹌鹑间脑内的分布。结果显示,orexinA阳性神经元胞体主要分布在间脑中下丘脑区的室旁核、室周区、外侧核和后内侧核,其阳性纤维则投射到丘脑和下丘脑的广大区域,其中在圆核、三角核、前脑外侧束、第五额束、视顶盖、中央白质层和外侧核等处较密集。结果表明orexin A存在于鹌鹑的间脑内,但其分布与大鼠之间有明显的差异。     

糖尿病大鼠大脑皮层脑源性神经营养因子的表达及内锥体神经元变化的

目的探讨糖尿病对大脑皮层脑源性神经营养因子（BDNF）表达的影响及对内椎体神经元的影响。方法利用链脲佐菌素（STZ）诱导制作成年大鼠糖尿病模型（n=10）,正常大鼠作为对照组（n=10）。3个月后,用ELISA的方法检测大脑皮层BDNF的表达水平,用中性红染色观察大脑皮层第Ⅲ层内椎体神经元的数量和形态的变化。结果糖尿病大鼠大脑皮层BDNF的表达水平为（15.64±2.22）ng/g,低于正常大鼠的（24.47±3.53）ng/g（P〈0.01）。中性红染色发现,糖尿2病大鼠内椎体神经元的数量为（95.64±2.22）个/0.16 mm,2低于正常大鼠的（125.37±16.01）个/0.16mm（P〈0.01）,且部分内锥体神经元的胞体出现皱缩。结论糖尿病可以导致大脑皮层BDNF表达水平的下降,同时引起大脑皮层第Ⅲ层内锥体神经元的数量和形态发生改变。     

体外定向诱导小鼠骨髓间充质干细胞分化为神经元样细胞

[目的]分离和克隆小鼠骨髓间充质干细胞,并诱导分化为神经元样细胞。[方法]利用Percoll密度梯度离心的方法进行小鼠骨髓间充质干细胞分离及培养,分别采用β-巯基乙醇和BHA诱导分化为神经元样细胞。用神经元特异性烯醇化酶和神经纤维丝蛋白免疫细胞化学方法对已分化的神经元样细胞进行鉴定和分化率分析。[结果]经2种诱导剂诱导的小鼠骨髓间充质干细胞均出现神经元样细胞的分化,胞体呈神经元状,伸出较长轴突样和树突样突起且有分支。而且免疫细胞化学鉴定显示,诱导分化后的神经元样细胞神经元特异性烯醇化酶染色和神经纤维丝蛋白免疫细胞化学染色均呈阳性,β-巯基乙醇诱导分化细胞表达NSE的阳性率为（86.8±2.7）%;诱导分化细胞表达Neurofilament200 kD的阳性率为（75.2±2.3）%;BHA诱导分化细胞表达NSE的阳性率为（80.5±2.2）%;诱导分化细胞表达Neurofilament200 kD的阳性率为（73.2±1.6）%。[结论]小鼠骨髓间充质干细胞能够在诱导剂β-巯基乙醇和BNA的诱导下体外诱导分化为神经元样细胞。     

GABAergic神经元在BARREL和VPM区组织结构及形态特点的免疫组织化学研究

[目的]研究GABAergic神经元在VPM和"barrel"区的组织结构及形态特点;[方法]通过免疫组织化学的方法和激光共聚焦电子显微镜研究GABAergic神经元在VPM和"barrel"区分布状态;[结果]GABAergic神经元在VPM和"barrel"区分布状态不同,信息传递这2个区域编码程度也不一样;GABAergic在VPM区主要分布在列与列之间,且呈非对称分布,而GABAergic神经元的胞体、树突和轴突出现限定在"barrel"内,与周围"barrel"很少形成突触联系。[结论]提示VPM和"barrel"可能在信息传递及处理过程中具有不同的功能。     

IFN—γ在大鼠胸段脊髓内的分布

为进一步探讨免疫－神经－内分泌三大系统之间的关系，用免疫组织化学SP法，对大鼠胸段脊髓内IFN－γ样免疫反应产物的分布进行了研究，结果表明，IFN－γ样免疫反应产物广泛分布于胸段脊髓各板层，其中背角Ⅰ，Ⅱ，Ⅲ层，胸髓中间带外侧核，腹角Ⅺ层内可见珐较高密度的阳性胞体和树突，中间带和腹角内的阳性胞体的树突还伸负外侧索和腹索，有时可达脊髓边缘。     

Merging of modalities in the optic tectum: infrared and visual integration in rattlesnakes

The optic tectum of pit vipers (Crotalinae) contains a layer of infrared-sensitive neurons subjacent to the visual layer; these indirectly receive input from the facial pit organs. They respond transiently to the appearance or motion of warm objects within their 25 degrees to 70 degrees excitatory receptive fields (some have inhibitory regions) and presumably allow the snake to orient or strike toward prey. The infrared and visual spatiotopic tectal maps have similar but not identical axes; the infrared magnification is greater than that for vision. Bimodal neurons have receptive fields for each modality that reflect the disparity of the two maps. This finding suggests that (i) during development the infrared and visual fibers spread out independently to fill available tectal sites and (ii) bimodal neurons form local connections without regard to establishing spatial correspondence between the two modalities.     

Filtering of visual information in the tectum by an identified neural circuit

The optic tectum of zebrafish is involved in behavioral responses that require the detection of small objects. The superficial layers of the tectal neuropil receive input from retinal axons, while its deeper layers convey the processed information to premotor areas. Imaging with a genetically encoded calcium indicator revealed that the deep layers, as well as the dendrites of single tectal neurons, are preferentially activated by small visual stimuli. This spatial filtering relies on GABAergic interneurons (using the neurotransmitter γ-aminobutyric acid) that are located in the superficial input layer and respond only to large visual stimuli. Photo-ablation of these cells with KillerRed, or silencing of their synaptic transmission, eliminates the size tuning of deeper layers and impairs the capture of prey.     

Transport of protein by goldfish optic nerve fibers

After tritiated leucine was injected into the eye of goldfish, radio-active protein synthesized by the ganglion cell bodies moved down the optic axons at an average rate of 0.4 mm per day. Radioautograms of the optic tectum in which these axons end show that, as early as 24 hours after the injection, before the radioactivity in the tectal layer containing the optic axons had risen above background level, the layer containing the axon terminals was already heavily labeled. The radioactivity in the terminals reached a maximum about 48 hours after the injection and remained approximately constant for at least 23 days thereafter, whereas the radioactivity in the fiber layer increased significantly during the same interval, as the slowly moving protein component entered it. Thus there appears to be a special mechanism for rapid transport of protein from the cell body to the synaptic terminals, as well as a slower movement of protein down the axon.     

Evidence That Cut Optic Nerve Fibers in a Frog Regenerate to Their Proper Places in the Tectum

The frog's retina projects into the superficial neuropil of the opposite tectum in four functionally different layers of terminals. Each layer displays a continuous map of the retina in terms of its particular function. The four maps are in register. The fourth-dimensional order is reconstituted after section and regeneration of the optic fibers.     

Radioautography of the optic tectum of the goldfish after intraocular injection of ( 3 H)proline

Radioautography of the optic tectum of the goldfish, performed after injection of [(3)H]proline into the contralateral eye, effectively resolves several distinct layers of retinal synapses. Silver grains are found unilaterally over nerve tracts containing efferent fibers from the tectum, a result that suggests intercellular migration of labeled molecules. The low background and high specific grain density obtained with [(3)H]proline radioautography indicate the usefulness of this technique for the elucidation of neuroanatomical connections in the visual system.     

Transported proteins in the regenerating optic nerve: regulation by interactions with the optic tectum

The transport of specific proteins in regenerating optic fibers of goldfish depends on the presence or absence of the optic tectum. When optic fibers were allowed to contact the tectum, amounts of rapidly transported proteins having molecular weights between 120,000 and 160,000 increased, and a species of molecular weight 26,000 reverted to normal levels. When nerves were prevented from contacting the tectum, the amount of the 26,000-molecular weight protein remained high for months. Amounts of other transported proteins, in particular a group of acidic components of molecular weight 44,000 to 49,000 that increase greatly at early stages of regeneration, proved to be independent of the tectum.     

Two visual systems in the frog

After unilateral removal of the optic tectum in frogs, the cut optic tract regenerates to the remaining ipsilateral tectum. Although the orienting movementselicited by moving objects (food or threats) are now directed mirror-symmetrically to normal responses, these frogs correctly localize stationary objects as barriers. Apparently, thalamic and tectal visual mechanisms can operate independently.     

Visual instruction of the neural map of auditory space in the developing optic tectum

Neural maps of visual and auditory space are aligned in the adult optic tectum. In barn owls, this alignment of sensory maps was found to be controlled during ontogeny by visual instruction of the auditory spatial tuning of neurons. Large adaptive changes in auditory spatial tuning were induced by raising owls with displacing prisms mounted in spectacle frames in front of the eyes; neurons became tuned to sound source locations corresponding to their optically displaced, rather than their normal, visual receptive field locations. The results demonstrate that visual experience during development calibrates the tectal auditory space map in a site-specific manner, dictating its topography and alignment with the visual space map.     

Retrograde axonal transport in the central nervous system

When horseradish peroxidase is injected into the optic tectum of a chick, axons of ganglion cells transport it centripetally to their cell bodies in the retina at a rate of about 72 millimeters per day. After intraocular injections in the young chick, the peroxidase is transported centripetally along efferent axons, and is concentrated in cell bodies within the isthmo-optic nucleus. This retrograde movement of protein from axon terminal to cell body suggests a possible mechanism by which neurons respond to their target areas.     

Corresponding spatial gradients of TOP molecules in the developing retina and optic tectum

The topographic map of cell position in the avian retina is inverted in its projection to the optic tectum. Dorsal retinal ganglion cell axons project to ventral tectum, and ventral retinal ganglion cells project to dorsal tectum. Topographic gradients of toponymic (TOP) cell surface molecules along the dorsoventral axes of retina and tectum also are inverted. TOP molecules are most abundant in dorsal retina and ventral tectum and least abundant in ventral retina and dorsal tectum during the period of initial retinal-tectal interaction. Thus, TOP molecules may be involved in orienting the retinotectal map.