家兔小脑中央核向脊髓直接投射的研究

本实验将WGA-HRP分別注入家兔脊髓一侧的颈、胸、腰等不同节段,逆行追踪小脑中央各核向脊髓的直接投射。结果表明,小脑中央核的标记神经元恒定地见于颈段(C_1～C_4)注入例动物,而未见于下颈段(C_6～C_8)和胸腰段注入例动物。标记神经元仅出现于注入侧对侧的小脑顶核及间位核的尾侧部。研究结果提示,家兔小脑顶核及间位核的尾侧部,有向颈髓的直接越边投射。本结果为进一步探讨小脑对躯体运动的调节功能提供形态学基础。     

家兔大脑、小脑和顶盖向脊髓直接投射的研究

将辣根过氧化物酶(HRP)分别注入家兔脊髓单侧的颈、胸和腰等不同节段,逆行追踪大脑、小脑和顶盖向脊髓的直接投射。结果表明,大脑皮质的HRP标记神经元仅见于C_(2-7)注入例动物;小脑中央核的标记神经元仅见于C_(2-4)注入例动物;顶盖上丘的标记神经元仅见于C_(2、3)注入例动物;而均未见于胸腰段注入例动物。标记神经元主要分布于注入侧的对侧。本研究确信,由大脑皮质发出的皮质脊髓束投射到脊髓C_(1-7)节段;由小脑中央核发出的小脑脊髓束投射到脊髓C_(1-4)节段,由顶盖发出的顶盖脊髓束投射到脊髓C_(1-3)节段。     

大鼠小脑核到脊髓的投射——HRP法研究

向23只大鼠的颈、胸、腰、骶各段脊髓的一侧灰质内注射30％HRP(Sigma Ⅵ)水溶液0.3～2.0μl,TMB反应,观察了小脑核中标记细胞的分布。小脑核到脊髓的投射细胞主要位于小脑顶核的中部,对侧较多。标记细胞分布于顶核各部,但以腹外侧及内侧部较为密集。在顶核和间位核之间的部位(有小脑皮质前庭纤维经过)以及间位核后部内侧亦有较多标记细胞。两侧的齿状核中有少量标记细胞。小脑核细胞主要投射到颈髓上部(C_(3～4)),少量可达颈髓下部(C_(5～8))。胸髓以下未见有投射纤维。     

大鼠前庭神经核群向腰髓投射特征——BDA法逆行研究

目的　研究大鼠前庭神经核群向脊髓的投射纤维特征。方法　在 7例SD大鼠采用结合生物素的葡聚糖胺(BDA)逆行法观察大鼠前庭核群向脊髓的投射。结果　除前庭神经上核 (SVN)外的其余各前庭核均有向大鼠腰髓的投射 ,单侧注射的实验动物中 ,前庭神经内侧核 (MVN)、外侧核 (LVN)和降核 (DVN)的标记神经元可见于双侧 ,其中MVN和LVN的标记神经元以注射同侧占优势 ,而DVN标记神经元两侧数量基本一致。结论　大鼠前庭脊髓尾侧束发出纤维投向脊髓腰段     

运用HRP逆行追踪法对家兔脊髓小脑束起始细胞的研究

本文在11只家兔小脑内,进行单侧或双侧辣根过氧化物酶注射,以研究脊髓各部标记神经元的分布。同时,为确定胸髓以下这些神经元轴突是否在脊髓内交叉上行,其中4只家兔在注射前,还作了下胸髓的一侧半断。标记的脊髓小脑束起始细胞在脊髓中分布甚广。位于颈髓的有:1.中央颈核(C_(1～4));2.Ⅵ层内侧部细胞(C_2～T_1);3.Ⅶ层中央部细胞(C_(4～8));4.后角Ⅳ～V层细胞(C_(5～8))。胸髓以下的标记细胞可分两大类:1.具有不交叉上行轴突的细胞为:(1)背核(T_(2～L_4));(2)后角Ⅳ～Ⅵ层细胞(T_2～L_6)。2.具有交叉越边上行轴突的细胞则包括:(1)脊髓前角边缘细胞(L_(3～6));(2)Ⅶ层内侧群细胞(L_5以下骶尾髓);(3)后角V层细胞(骶尾髓);(4)前角Ⅶ～Ⅷ层细胞(骶尾髓)。家兔脊髓小脑束起始细胞的分布和轴突投射特点,与猫相类似。这对进一步用家兔研究脊髓小脑系统的解剖学和生理学打下一定基础。     

鸡脊髓小脑束起始神经元的节段性分布

目的:探索鸡脊髓小脑束起始细胞在脊髓的分布规律.方法:采用压力注射法将辣根过氧化物酶(HRP)引入鸡小脑Ⅴ、Ⅵ、Ⅶ、Ⅷ、Ⅸ诸叶,逆行追踪脊髓小脑束起始神经元的分布.结果:(1)鸡脊髓小脑束起始神经元分布于Clarke氏柱、腹角灰质、腹角内缘、腹角外缘、外侧索和腹侧索,并在禽类所特有的边缘柱发现起始神经元.(2)标记神经元在腰骶膨大部出现最多.(3)分别注射Ⅵ、Ⅶ叶在脊髓均有标记细胞出现,而注射Ⅴ叶、Ⅷ或Ⅸ叶在脊髓没有出现标记细胞.结论:鸡的脊髓小脑束主要起始于腰骶段脊髓,主要投射向小脑的Ⅵ、Ⅶ叶.     

大鼠脊髓向中央颈核和外侧颈核的投射——PHA-L顺行追踪研究

将菜豆白细胞凝集素(PHA-L)分别注入下颈髓、胸髓、腰髓和骶髓等不同脊髓节段,顺行追踪脊髓向中央颈核和外侧颈核的投射。观察结果表明,脊髓不同节段注入PHA-L,在中央颈核和外侧颈核均可见到标记末梢;比较各节段脊髓的投射分布,未能发现明显的定位关系。一侧脊髓灰质注入,在两侧中央颈核均观察到标记末梢,但主要见于同侧;外侧颈核的标记末梢仅见于同侧。结果提示,各节段脊髓均发出纤维投射到同侧中央颈核和外侧颈核。     

脊髓小脑束的起始及投射

近年来的研究表明脊髓小脑束神经元的胞体广泛分布于整个脊髓。这些神经元的胞体有的比较集中称之为核，有的比较分散称之为群，它们的轴突在小脑的投射范围也比较广泛且有定位的设射关系。本文就这些神经元胞体在脊髓内的分布，神经元轴突的走行及其在小脑皮质的投射部位等进行综述。     

家兔脊髓向延髓外侧网状核投射的体部定位——HRP顺行法研究

本实验用HRP顺行传递法研究了家兔脊髓向外侧网状核的纤维投射,结果是: 1.颈、胸和腰髓都有少数的神经元发出纤维投射于双侧的三叉神经下亚核。 2.颈、胸和腰髓至外侧网状核的投射都是双侧性的,但颈髓以同测投射为主,腰髓以对侧投射为主,胸髓至双侧的投射无明显差别。 3.脊髓神经元主要投射于外侧网状核的尾侧半,有体部定位关系。颈髓投射于大细胞亚核的外侧3/5及相邻的部分小细胞亚核;胸髓投射于大细胞亚核的内侧3/5及相邻接的部分小细胞亚核;腰髓投射于小细胞亚核及相邻接的一部分大细胞亚核,相互间有部分重叠。     

大鼠蓝斑到脊髓的局部定位投射——荧光组织化学和HRP法联合应用的研究

在24只大鼠的颈、胸、腰、骶各段脊髓的一侧灰质注射HRP后,用荧光组化和HRP法联合应用的方法研究了蓝斑到脊髓的投射。蓝斑发出NA能纤维投射到脊髓各部并有一定的局部定位关系。蓝斑到脊髓投射的神经元主要集中在此核的腹侧部,但背侧部亦有少量授射至颈髓的神经元。蓝斑投射到颈髓的神经元主要位于蓝斑的尾侧部,而投射到骶髓的神经元主要位于颅侧部,两者有一定的重叠。     

大鼠最后区和尾侧延髓5—羟色胺免疫细胞化学定位

本文应用免疫细胞化学PAP法研究5-羟色胺样免疫反应阳性结构在大鼠最后区(AP)和尾侧延髓内的定位.结果发现5-HT样轴突和轴突终末,主要位于AP腹侧和腹外侧边缘,呈高密度串珠状或点状膨体终末,在中央部分则分布稀少.这些串珠状轴突终末还分布在延髓中央管、尾侧延髓孤束核、迷走神经背核和舌下神经核等处.然而,5-HT能标记的胞体和轴突仅发现在延髓中缝隐核、中缝苍白核和尾侧延髓腹外侧区内.本实验证实的最后区、延髓中央管和延髓腹外侧区尾侧的5-HT免疫反应定位,在国内尚未见文献报道.上述结果为深入探讨5-HT在呕吐、内脏感觉通路中的作用以及阐明5-HT神经递质通路等提供了形态学依据.     

猫丘脑中央外侧核的皮质下传入联系

本实验用HRP逆行性轴浆运输技术,对猫丘脑中央外侧核的传入纤维联系及其局部定位关系进行了观察。投射至丘脑中央外侧核尾侧区的主要核团包括:外侧膝状体腹核背侧带、丘脑网状核特别是它的背侧部、上丘深层,以同侧为主。板内核、丘脑下部外侧区和黑质网状部神经元的轴突终止在同侧丘脑中央外侧核吻侧区。丘脑中央外侧核全长的传入起自脑干网状结构和前庭神经核,呈双侧投射。前者以同侧为主,后者以对侧占优势。同侧未定带,顶盖前区、动眼神经核周围的细胞群、对侧三叉神经感觉主核、楔束核、薄束核以及小脑齿状核内也含有少量标记细胞。我们还观察到HRP注射中心区位于中央外侧核并扩散至丘脑腹前核者,同侧脚内核含大量HRP阳性细胞,而Gudden被盖腹侧核内充满密集的标记终末。这些结果表明,丘脑中央外侧核可能涉及多种感觉和运动功能。     

Connections of Purkinje cell axons of lobule X with vestibulospinal neurons projecting to the cervical cord in the rat

Connections of Purkinje cell axons of lobule X (nodulus vermis) with vestibulospinal neurons have been demonstrated in the rat, by anterograde labeling of axons with biotinylated dextran (BD) injected into sublobule Xa and by retrograde labeling of neurons with cholera toxin subunit B (CTB) injected into cervical segments. Labeled terminals of Purkinje cell axons were numerous in the superior vestibular nucleus, the parvocellular (MVpc) and the caudal part (MVc) of the medial vestibular nucleus (MV), and group y. A limited number of labeled terminals were seen in the caudal part of the descending vestibular nucleus (DV). Occasional labeled terminals were seen in the lateral part of the lateral vestibular nucleus (LV) whereas few labeled terminals were seen in the magnocellular part of the MV (MVmc). Vestibulospinal neurons labeled from the C2 and C3 segments were seen bilaterally in the MVmc, MVpc, MVc, and DV, and ipsilaterally in the LV. CTB-labeled vestibulospinal neurons in contact with BD-labeled terminals of Purkinje cell axons were identified in the lateral part of the MVpc, near the border between the MVpc and MVmc, or close to the dorsal acoustic stria, and in the middle part of the MVc at its rostral level. The present study suggests that Purkinje cells of lobule X regulate the output of cervical-projecting vestibulospinal neurons in the MVpc and MVc.     

大鼠臂旁核内接受孤束核内脏传入之神经元同时接受中央杏仁核的反馈调节──溃变、HRP法结合包埋后免疫电镜研究

为研究来自孤束核的内脏传导信息在臂旁核水平是否接受中央杏仁核的反馈调节及其递质性质，以及孤束核—臂旁核—中央杏仁核传导通路中，在臂旁核水平是否接受ＧＡＢＡ的调节，本文将ＨＲＰ注入中央杏仁核进行顺、逆行标记，同时将兴奋性氨基酸毒素海人酸注入孤束核进行损毁，观实其顺行溃变终末，取外侧臂旁核超薄切片后结合抗ＧＡＢＡ的免疫电镜染色，观察发现有下列几种标记；（１）顺行溃变终末，所有的都与臂旁核神经元形成非对称性突触；（２）ＨＲＰ标记终末有两类：第一类和臂旁核神经元形成对称性突触，占ＨＲＰ标记终末总数的８０％以上，第二类与臂旁核神经元形成非对称性突触，另外有大量的ＨＲＰ标记的胞体和树突；（３）胶体金标记的ＧＡＢＡ阳性终末，皆与突触后结构形成对称性突触；（４）ＧＡＢＡ／ＨＲＰ双标记终末，具有ＧＡＢＡ免疫阳性终末和第一类ＨＲＰ标记终末的共同特征。上述几种标记在臂旁核内有以下几种关系：（１）溃变终末和ＧＡＢＡ阳性终末与同一个ＨＲＰ标记或非标记的突形成轴－树突触；（２）溃变终末和第一类ＨＲＰ标记终末共同终止于同一非标记讨突；（３）溃变终末与ＨＲＰ标记树突或胞位形成非对称性突触；（４）ＧＡＢＡ／ＨＲＰ双标记终末与非标记树突或胞体?     

猫眶回向脑干的下行投射—WGA-HRP顺行追踪研究

为了探讨猫眶回至脑干下行投射的起源和终止部位,分别向眶回前部和后部注射WGA-HRP,追踪在脑干里的顺行标记终末支,结果如下: 1.眶回前部注射,标记终未支见于三叉神经脊束核各亚核、感觉主核、孤束核和臂旁核等,而眶回后部注射,标记终末支多位于中脑中央灰质和臂旁核等。 2.三叉神经感觉核簇由尾侧亚核吻部至感觉主核,于背侧部或背内侧部形成连续柱形标记区,其中吻侧亚核标记最密。孤束核的标记见于闩以上,吻侧部标记密集。臂旁核内的标记在眶回前部注射例多见于其内侧核;在眶回后部注射例,外侧核内标记稍多。中脑中央灰质里的标记区由尾向吻侧,逐渐由背外向腹外转移。 3.各部的标记终末支主要见于注射同侧,对侧标记较少甚至没有。     

Kappa opioid receptor immunoreactivity in the nucleus accumbens and caudate-putamen is primarily associated with synaptic vesicles in axons

A rabbit polyclonal antiserum, raised against a C-terminal oligopeptide of the mouse kappa opioid receptor, was used to localize the cellular distribution of kappa receptors in the dorsal and ventral striatum of rats with light and electron microscopic immunocytochemistry. Prominent, diffuse kappa receptor immunoreactivity was present in the nucleus accumbens, particularly in the shell, ventral caudate-putamen and olfactory tubercle. The density of receptor immunoreactivity decreased in more dorsal areas of the caudate-putamen. In contrast, neuronal cell bodies stained clearly in the dorsal endopiriform nucleus, claustrum and layer VI of the adjacent cerebral cortex. Observations at the electron microscopic level in the dorsomedial shell of the nucleus accumbens and caudate-putamen revealed that the kappa receptor immunoreactivity was predominantly located in axons, often associated with synaptic vesicles, remote from the terminal or preterminal area. The few terminals which were labeled made slightly more asymmetrical than symmetrical contacts and the percentage of asymmetrical contacts observed was greater in the caudate than in the accumbens. A small number of postsynaptic spines was labeled; most of them were contacted by asymmetrical terminals. No labeling was observed in dendritic shafts.Thus, the predominant localization of kappa receptor immunoreactivity in axons is consistent with its role as a major inhibitor of glutamate and dopamine release in the dorsal and ventral striatum.     

大鼠弓状核内神经紧张素能和P物质能阳性结构的免疫电镜双标记研究

用包埋前免疫电镜双标记技术研究大鼠下丘脑内的神经紧张素(NT)和P物质(SP)分布的超微结构。证实在弓状核内存在NT样和SP样免疫反应阳性的胞体、树突和轴突。NT样和SP样免疫反应阳性的树突和轴突均可接受免疫反应阴性结构的非对称性传入突触。SP样免疫反应阳性轴突终末除可与免疫反应阴性的树突和胞体形成对称性传出突触外, 还可与NT样免疫反应阳性胞体形成对称性轴-体突触。本研究首次直接证实大鼠弓状核内的NT能神经元接受SP能神经的支配。     

Differential expression of vesicular glutamate transporters by vagal afferent terminals in rat nucleus of the solitary tract: projections from the heart preferentially express vesicular glutamate transporter 1

The central projections and neurochemistry of vagal afferent neurones supplying the heart in the rat were investigated by injecting cholera toxin B-subunit into the pericardium. Transganglionically transported cholera toxin B-subunit was visualized in the medulla oblongata in axons and varicosities that were predominantly aggregated in the dorsomedial, dorsolateral, ventrolateral and commissural subnuclei of the caudal nucleus of the solitary tract. Unilateral vagal section in control rats prevented cholera toxin B-subunit labeling on the ipsilateral side of the nucleus of the solitary tract. Fluorescent and electron microscopic dual labeling showed colocalization of immunoreactivity for vesicular glutamate transporter 1, but only rarely vesicular glutamate transporters 2 or 3 with cholera toxin B-subunit in terminals in nucleus of the solitary tract, suggesting that cardiac vagal axons release glutamate as a neurotransmitter. In contrast, populations of vagal afferent fibers labeled by injection of cholera toxin B-subunit, tetra-methylrhodamine dextran or biotin dextran amine into the aortic nerve, stomach or nodose ganglion colocalized vesicular glutamate transporter 2 more frequently than vesicular glutamate transporter 1. The presence of other neurochemical markers of primary afferent neurones was examined in nucleus of the solitary tract axons and nodose ganglion cells labeled by pericardial cholera toxin B-subunit injections. Immunoreactivity for a 200-kDa neurofilament protein in many large, cholera toxin B-subunit-labeled nodose ganglion cells indicated that the cardiac afferent fibers labeled are mostly myelinated, whereas binding of Griffonia simplicifolia isolectin B4 to fewer small cholera toxin B-subunit-labeled ganglion cells suggested that tracer was also taken up by some non-myelinated axons. A few labeled nucleus of the solitary tract axons and ganglion cells were positive for substance P and calcitonin gene-related peptide, which are considered as peptide markers of nociceptive afferent neurones. These data suggest that the population of cardiac vagal afferents labeled by pericardial cholera toxin B-subunit injection is neurochemically varied, which may be related to a functional heterogeneity of baroreceptive, chemoreceptive and nociceptive afferent fibers. A high proportion of cardiac neurones appear to be glutamatergic, but differ from other vagal afferents in expressing vesicular glutamate transporter 1.     

A GABA immunocytochemical study of rat motor thalamus: light and electron microscopic observations.

A light and electron microscopic study of GABA-immunoreactive neurons and profiles in the ventroanterior-ventrolateral and ventromedial nuclei of rat dorsal thalamus was conducted using antiserum raised against GABA. Less than 1% of the neurons in these motor-related nuclei exhibited GABA immunoreactivity, confirming previous reports that these nuclei are largely devoid of interneurons. Immunoreactive neurons in the ventral anterior-ventral lateral complex and ventromedial nucleus were bipolar or multipolar in shape, and tended to be smaller than non-immunoreactive neurons. GABA immunoreactivity in the neuropil consisted of labeled axon terminals and myelinated and unmyelinated axons, and was lower in the ventral anterior-ventral lateral complex and ventromedial nucleus than in neighboring thalamic nuclei. The density of neuropil immunolabeling was slightly higher in ventral anterior-ventral lateral complex than in ventromedial nucleus. GABA-immunoreactive axon terminals, collectively termed MP boutons for their medium size and pleomorphic vesicles (and corresponding to "F" profiles of some previous studies of thalamic ultrastructure), formed symmetric synapses and puncta adhaerentia contacts predominantly with large and medium-diameter (i.e. proximal) non-immunoreactive dendrites. Approximately 12 and 18% of boutons in the ventral anterior-ventral lateral complex and ventromedial nucleus, respectively, were GABA-immunopositive. Many of these immunoreactive profiles probably arose from GABAergic neurons in the thalamic reticular nucleus, substantia nigra pars reticulata and entopeduncular nucleus. Two types of non-immunoreactive axon terminals were distinguished based on differences in morphology and synaptic termination sites. Boutons with small ovoid profiles and round vesicles that formed prominent asymmetric synapses onto small-diameter dendrites were observed. Mitochondria were rarely observed within these boutons, which arose from thin unmyelinated axons. These boutons composed approximately 82 and 74% of boutons in the ventral anterior-ventral lateral complex and ventromedial nucleus, respectively, and were considered to arise predominantly from neurons in the cerebral cortex. In contrast, boutons with large terminals that contained round or plemorphic vesicles and formed multiple asymmetric synapses predominantly with large-diameter dendrites were also observed. Puncta adhaerentia contacts were also common. Mitochondria were numerous within large boutons with round vesicles, which arose from myelinated axons. Many of the large boutons were likely to have originated from neurons in the cerebellar nuclei. Approximately 6% of the boutons in the ventral anterior-ventral lateral complex and 8% in ventromedial nucleus were of the large type.(ABSTRACT TRUNCATED AT 400 WORDS)     

Quantitative and ultrastructural study of ascending projections to the medial mammillary nucleus in the rat

Summary We analyzed the termination pattern of axons from the superior central nucleus and the ventral tegmental nucleus of Gudden within the medial mammillary nucleus (MM) in the rat. The neuropil of the MM consists of two classes of terminals, that is, terminals containing round synaptic vesicles and forming asymmetric synaptic contact, and terminals containing pleomorphic synaptic vesicles and forming symmetric synaptic contact. The number of axodendritic terminals with round vesicles is almost equal to that of terminals with pleomorphic vesicles. Almost all axosomatic terminals contain pleomorphic vesicles with symmetric synaptic contact. Injection of WGA-HRP into the central part of the superior central nucleus permitted ultrastructural recognition of many anterogradely labeled terminals within the median region of MM. The labeled terminals contacted mainly intermediate (1–2 m diameter) and proximal dendrites (more than 2 m diameter) as well as the neuronal somata. Serial ultrathin sections of neurons of the median region of the MM revealed that 37% of the axosomatic terminals were labeled anterogradely. The pars compacta of the superior central nucleus had reciprocal connections with the median region of MM. The axon terminals from this nucleus occupied 53% of axosomatic terminals, and contacted mainly intermediate dendrites. Following injection of WGA-HRP into the ventral tegmental nucleus, many labeled terminals were found in the medial and lateral regions of MM. They contacted mainly intermediate dendrites as well as neuronal somata. In the medial region, 78% of axosomatic terminals contacting retrogradely labeled neurons were labeled anterogradely. All labeled terminals from these nuclei contained pleomorphic vesicles, and made symmetric synaptic contact.