皮质后索核投射纤维终末的超微结构的突触联系

本文采用顺行溃变法对猫后索核内皮质索核投射纤维终末的超微结构和突蟹联系进行了研究。在电损毁皮质２－５天后，电镜下发现后索核内皮质后索核纤维终末存在三种溃变形式；即电子致密型、神经微线型透明型，以电子致密型最为多见。溃变的纤维终末常较粗大，主要含有大量密集的圆形突触小泡，主要与神经元的树突或胞体接触形成不对称的轴－－树突触，轴－轴突触、轴－体突触、轴－树－树系列突触，并参与形成以树突为中心的突触复事     

下橄槛榄内侧副核中继的大脑-小脑通路─-HRP法电镜研究

目的：为了观察大鼠橄榄内侧副核（MAO）内皮质溃变终未与橄榄小脑投射神经元间的突触联系；。方法：用顺行演变结合HRP电镜技术，观察12只大民橄榄内侧副核；。结果：1．皮质溃变终末分布于双侧MAO的中、下段，以同侧多见；2．溃变终末以电子致密型溃变为主，也见少数神经微丝型和电子透亮型溃变；3．溃变终未与HRP标记的树突或胞体形成轴-树和轴-体突触，其特点是：①轴一树突触多见，多为含圆形清亮小泡终未形成的非对称型突触，少数为含扁平小泡终末形成的对称型突触；②轴-体突触少，多形成对称型突触；③正常终末与溃变终末共同与HRP标记树突形成以树突为中心的汇聚型突触复合体。讨论：结果表明，皮质-小脑通路在下橄榄内侧副核中存在着单突触联系。     

大鼠下丘脑室旁核向孤束核投射的电镜研究

用直流电电解损毁大鼠下丘脑一侧室旁核（Pa)后，电镜观察同侧孤束核内侧亚核（Sol M)中Pa投射纤维终末的超微结构及突触联系，结果：Sol M中有Pa下行投射纤维终末存在，构成的突触以轴－树突触为主，轴－棘，轴－轴突触为少量，无轴－体突触，Pa终末内的突触小泡以圆形清亮囊泡为主，突触的类型主要为Gray I型，Sol M 中有少量Pa终末参与构成突触球，Pa下行投射终末溃变以电子致密型为主，有少量水样溃变。     

皮质丘脑纤维终末的超微结构及突触联系

采用顺行溃变的方法,电损毁猫的皮质体感Ⅰ区,4～5天以后,在电镜下观察 VPL 内的皮质丘脑纤维终末。结果证明:存在大量的电子致密型的溃变终末。溃变的终末均很小,并且含有圆形无颗粒小泡。在 VPL 内发现有4种类型的突触:(1)轴～树突触;(2)轴～体突触;(3)轴～轴突触;(4)突触复合体。     

大鼠大脑皮质—蓝斑—小脑通路：HRP溃变电镜研究

目的 为了在超微水平上证实皮质－ＬＣ－小脑通路的存在。方法 采用顺行溃变与ＨＲＰ逆行示踪相结合电镜技术。结果 在ＬＣ颅则部观察到中（ｄ〈２ｕｍ）、小（ｄ〈１ｕｍ）型溃变前囊，以电子致密型为主，偶见神经微丝型溃变。电子致密型溃变前囊中的小泡以圆形清亮小泡为主，偶见大颗粒小泡和扁平小泡。同时在ＬＣ的颅侧部观察到大量ＨＲＰ逆标神经元胞体和树突，部分溃变前囊与ＨＲＰ逆标神经元形成非对称型轴－树突触，部分溃变的前囊与非ＨＲＰ标记树突形成轴－树突触。结论皮质－ＬＣ投射和ＬＣ－小脑投射在ＬＣ内存在单突触连接；皮质纤维不仅投向ＬＣ内的小脑投射神经元，也投向ＬＣ内其它神经元。     

大鼠大脑皮质─蓝斑─小脑通路──HRP溃变电镜研究

目的为了在超微水平上证实发质-LC-小脑通路的存在。方法采用顺行溃变与HRP逆行示踪相结合电镜技术。结果在LC颅测部观察到中（d＜2μm）、小（d＜1μm）型溃变前囊,以电子致密型为主,偶见神经微丝型溃变。电子致密型演变前囊中的小泡以圆形清亮小泡为主,偶见大颗粒小泡和扁平小泡。同时在LC的颅测部观察到大量HRP逆标神经元胞体和树突。部分溃变前囊与HRP逆标神经元形成非对称型轴-树突触。部分溃变的前囊与非HRP标记树突形成轴-树突触。结论皮质-LC投射和LC-小脑投射在LC内存在单突触连接;皮质纤维不仅投向LC内的小脑投射神经元,也投向LC内其它神经元。     

大鼠三叉神经初级纤维传入终末的溃变类型和突触联系

损毁大鼠三叉神经根,观察其纤维终末在中枢内的溃变。结果发现:存活第1天,溃变终末内线粒体肿胀,嵴断裂紊乱,透明小泡聚集;第2天溃变终末电子密度增加,出现典型的神经微丝增生型溃变;第3天溃变的细小轴突终末密度显著增高;第4天细小的溃变轴突终末皱缩并被胶质细胞包绕,有的终末突触小泡融合成大小不等的空泡。另外,较大的扇贝型溃变终末常与多个树突形成轴一树突触,其中有的进一步形成轴—树—树连续性突触,轴—轴突触偶见,表明三叉神经初级传入纤维与中枢内其它神经元联系密切而广泛,与其复杂的痛觉调控机制相一致。     

大鼠PMRN中皮质纤维终末的超微结构观察

为了观察ＰＭＲＮ中皮质纤维的超微结构和突联系，用溃变电技术首次观察了９只损毁感觉运动皮质大ＰＭＲＮ中的溃变终扣。溃变的皮质纤维表现为电子致密型变化。有两种含有不同小泡的终扣，含圆形清亮小含混合型小泡终扣，两种终扣均有大、小两型。两种终扣与ＰＭＲＮ神经元形成非对称型和对称型轴树突触，偶见对称型轴体突触。结果证明了皮质纤维与ＰＭＲＮ的单突触联系，也表明皮质ＰＭＲＮ纤维可能有侧支和轴突两投射。     

中缝大核下行抑痛作用在脊髓背角水平活动方式的形态学研究

用海人酸损毁家兔中缝大核,在透射电镜下观察其顺行溃变的投射纤维终末在颈髓背角内的分布,超微结构特征及突触联系。研究表明,家兔中缝大核—脊髓背角投射纤维终末分布于背角浅层和深层。投射纤维终末多呈圆顶形,直径多在1～2μm,含有大量圆形透明小泡和少量致密核心小泡或含有多形性透明小泡及少量致密核心小泡。投射纤维终末均作为突触前成分与背角神经元形成大量的轴—树突触和少量的轴—体、轴—棘突触,此外于背角浅层内还见到有溃变终末参与构成的汇聚型突触复合体。本文结果支持中缝大核—脊髓背角投射通路的下行抑痛效应是通过突触后抑制的作用方式实现的观点。     

大鼠下丘脑室旁核向孤束核投射的电镜研究

用直流电电解损毁大鼠下丘脑一侧室旁核(Pa)后,电镜观察同侧孤束核内侧亚核(Sol M)中Pa投射纤维终末的超微结构及突触联系。结果:Sol M 中有Pa 下行投射纤维终末存在,构成的突触以轴-权突触为主,轴-棘、轴-轴突触为少量,无轴-体突触。Pa 终末内的突触小泡以圆形清亮囊泡为主,突触的类型主要为Gray Ⅰ型。Sol M 中有少量Pa 终末参与构成突触小球。Pa 下行投射终末溃变以电子致密型为主,有少量水样溃变。     

猫丘脑腹后内侧核内皮质投射神经元的超微结构及突触联系

本文应用ＨＲＰ逆行追踪技术在电镜水平对猫丘脑腹后内侧核内投射神经元的超微结构及突触联系进行了研究。结果证明，该核内皮质投射神经元超微结构的特点为核较大，核膜常有凹陷，常柒色质较多，胞浆丰富，含有较多量的线粒体、粗面内质网及核糖体。标记的皮质投射神经元的树突主要作为突触后成分与轴突或突触前树突形成轴树突触或树树突触。此外，标记树突还可以作为中央树突参与形成树突型突触复合体。     

Immunocytochemical localization of beta2-adrenergic receptors in the rat spinal cord and their spatial relationships to tyrosine hydroxylase-immunoreactive terminals

The distribution of beta2-adrenergic receptors (beta2-ARs) in the rat spinal cord was investigated by immunocytochemistry using an antibody against beta2-ARs. The relationship between beta2-ARs and catecholaminergic terminals containing the catecholamine synthesizing enzyme, tyrosine hydroxylase (TH), in the dorsal horn was also examined by light and electron microscopy. beta2-AR-immunoreactivity (beta2-AR-IR) showing the appearance of fibers and puncta was particularly dense in laminae I and II of the dorsal horn. Moderate immunoreactivity was observed in the intermediolateral cell column, in the ventral horn and around the central canal. Additional immunoreactivity was detected in ependyma lining the central canal. Capsaicin treatment reduced, but did not eliminate, the immunostaining in the dorsal horn. Double immunofluorescence histochemistry for beta2-AR and TH showed no colocalization of the two antigens. By electron microscopy, beta2-AR-IR was found in dendrites as well as unmyelinated axons and axon terminals which contained many small clear vesicles and several large granular vesicles. Such terminals usually formed asymmetric synapses on labeled or unlabeled dendrites. TH-labeled terminals were often near both axonal and dendritic profiles containing beta2-AR-IR and sometimes made synaptic contacts with beta2-AR-labeled dendrites. However, beta2-AR-IR was found on the extrasynaptic portion of the plasma membrane. No synaptic contact was made between TH-labeled terminals and beta2-AR-labeled varicosities. These results demonstrated that beta2-ARs are localized on both nociceptive primary afferents and on dendrites in the rat dorsal horn and provide the ultrastructural evidence that beta2-ARs on both axonal and dendritic profiles are activated by catecholamines released from catecholaminergic terminals via volume transmission.     

Ultrastructural characteristics of substance P-immunoreactive terminals in marginal division of rat striatum.

In our previous work using immunocytochemical method combined with tract tracing techniques a new subdivision was described in the striatum of the rat. This "marginal division" is more densely filled with substance P, enkephalin and dynorphin B terminals than the rest of the striatum. In the present study, the synaptic organization of the substance P immunoreactive (SPIR) terminals in the marginal division of the rat striatum was studied using electron microscopy and immunocytochemistry for substance P (SP). Four major types of SPIR synapses were identified in the marginal division: axodendritic, axospinous, axo-axonal, and compound synapses. Axodendritic and axospinous synapses, in which the postsynaptic targets were small or large dendrites or spines, were the most common. A few axo-axonic synapses were observed as were several subtypes of compound synapses with more than two synaptic components. SPIR axon terminals formed the presynaptic components of all these synaptic types, but in one case an unlabeled bouton was observed making a synaptic connection onto a SPIR dendrite. Both symmetric and asymmetric SPIR synapses were observed in the marginal division. The vesicles in the SPIR presynaptic boutons were mostly pleomorphic although a few of them were round. The existence of asymmetric synapses, round synaptic vesicles and small postsynaptic dendrites distinguishes the ultrastructure of the marginal division from that of the other parts of the striatum. The complex characteristics of the synaptic organization in the marginal division implies that the SPIR terminals in the marginal division originate from a different source than those in the rest of the striatum. The complexity of the synaptic organization further suggests that the function of the marginal division is different from that of the rest of the striatum.

     

头面部感觉神经一级传入纤维终末的溃变类型及特点

目的：观察头面部感觉神经一级传入纤维终末的类型和超微结构特点,方法：用微量注射器向三叉神经节内注射微量纯酒精,损毁三叉神经一级神经元的胞体,从而导致其初级传入纤维终末溃变,电镜下对头面部感觉神经一级传入纤维终末的形成进行初步观察。结果：头面部感觉神经一级传入纤维终末产生了电子致密型和神经微丝增生型两种溃变,依据初级传入纤维终末形态大小,溃变特点分为五类：（1）普通型中央轴突终末（CCT）;（2）扇贝型中央轴突终末（SCT）;（3）细小的中央轴突终末（SCT）;（4）细小的轴突终末（ST）;（5）突触小球的中央轴突终末（GCT）;结论：三叉神经初级传入纤维终末与胶状质内的神经元建立了广泛的突触联系,是完成其复杂的痛觉调节机制的超微形态学基础。     

大鼠纹状体边缘区内P物质阳性终末的突触特征

本文用免疫电镜方法研究了大鼠纹状体边缘区内P物质阳性终末的突触特征。边缘区内可见4种P物质免疫反应阳性(SPIR)的突触,即轴树、轴棘、轴轴和复合突触。轴树和轴棘突触较常见,轴轴突触和复合突触较少。轴树和轴棘突触的突触后靶区为小或大的树突或棘,复合突触含两种以上突触成份。在边缘区内可观察到对称型和非对称型两种突触。SPIR突触前终扣内的小泡大部分是多形性的,很少为圆形。这些突触特征均和纹状体其它部位不同,提示边缘区内SPIR终末的来源可能和纹状体其它部位不同,同时也说明边缘区的功能可能和纹状体其它区不同。     

SYNAPTIC ULTRASTRUCTURE OF CAUDAL SPINAL TRIGEMINAL NUCLEUS IN RABBIT AND MOUSE

The caudal spinal trigeminal (CST) nucleus synapse consists of the pre- and postsynaptic mem branes and synaptic cleft. The active sites of the synapse consists of the presynaptic membranes. There are accumulated dense substances on the pre. and postsynaptic membranes, especially on the latter. Occasionally, subsynaptic cytoplasmic dense bodies ari: seen in the postsynaptic element, and intersynaptic filaments are found within the synaptic clefts. Synap- tic vesicles are located in the presynaptic terminals, Spherical, flat, granular and agranular synaptic vesi- cles are observed in presynaptic terminals. Numerous axon terminals, dendrites and axo dendritic, axosomatic, axoaxonic and dendrodendritic synapses were identified in the CST nucleus.. The dendrites were classified into type I (without synpatic vesicles) and type Il (few synaptic vesicles). Accord- iijg to the vesicle shape, the nuclear synapses are divided anto S (spherical), F (flat), S-F and F-S types. Anzong the observed synapses, about 20% were synaptic glomeruli. The functional significance of the synaptic pattem, glomeruli and vesicles in the CST nucleus are discussed.     

大鼠孤束核内含NT神经元的超微结构观察

用免疫电镜法对大鼠孤束核内侧亚核内NT-LI神经元的超微结构进行了观察。NT-LI产物可见于核周体、树突、轴突及终末内。标记轴突与树突构成轴-树突触最多见,轴-轴和轴-体突触少见。可见一些复合型突触和轴-树型自调节突触。此外一些NT-LI树突紧邻毛细血管。结果提示:(1)NT在孤束核调节心血管内脏活动中可能起着重要作用。(2)孤束核内NT神经元与血管之间可能存在神经-血管回路。