豚鼠脑桥被盖部位HRP逆行标记的传入联系

本研究应用HRP微电泳技术,将HRP注射至豚鼠脑桥的腹侧被盖和背侧被盖,追踪其逆行传入投射。将HRP注射至脑桥腹侧被盖后,中脑上丘腹侧的中脑水管周围灰质和网状结构交界处(MSR),具有较密集的标记神经元。此外,在下丘腹侧的楔状核(MLR)、三叉神经脊束核、延髓网状巨细胞核、前庭内和外侧核、蓝斑及其腹侧的网状结构部分以及脊髓颈膨大灰质,也观察到了标记细胞。将HRP注射至脑桥背侧被盖后,脑桥尾侧网状核和延髓巨细胞网状核的标记神经元较多,前庭内、外侧核和外侧楔束核也见到标记细胞,中脑部位仅在红核及其附近见到少量标记细胞。蓝斑及其腹侧的网状结构部分和脊髓灰质未见标记细胞。     

大鼠腰骼髓“内脏面”传出和上行投射神经元的定位分布——HRP与荧光金追踪法研究

用HRP与荧光金(FG)结合的示踪法,观察了大鼠腰骶髓“内脏面”副交感节前神经元和上行投射神经元的定位分布。发现FG注入一侧臂旁外侧核或Barrington核后,逆行标记的金色荧光细胞出现于双侧L_5～S_2的“内脏面”,细胞密集于后连合核和中间带外侧核(IML),此外,还出现于双侧的I层及外侧脊髓核(LSN)。HRP注射于一侧盆神经后,逆标细胞出现于术侧的L_6和S的IML,偶见于中介核(IC)。在IML内,HRP标记的副交感节前神经元位于其腹侧份,而FG标记的上行投射神经元主要位于背侧和背内侧部,亦可见少数FG标记细胞混杂在HRP标记细胞之间。本研究结合已有的研究对IML的命名、组成和功能以及LSN的组成进行了讨论。     

大鼠中脑导水管周围灰质向三叉神经脊束核尾侧亚核的5-羟色胺能投射

大鼠中脑导水管周围灰质(PAG)向三又神经脊束核尾侧亚核(Sp 5 C)投射的起源细胞在其吻、中、尾三个部分的分布不同,且由尾段向吻段有从腹侧向背侧移行的趋势。尾段的HRP逆标细胞主要位于PAG的腹外侧区、内侧区腹侧部;中段的标记细胞较多,主要见于腹外侧区、背侧区和背外侧区腹侧部,尚可见一些顺行标记的终末;吻段的标记细胞主要位于背外侧区,在上丘深层、Cajal氏中介核、Darkschewitsch氏核内,也可见标记细胞。标记细胞和终末均主要位于注射侧的PAG内。PAG向Sp 5 C投射的5-羟色胺(5-HT)样神经元主要位于PAG的中、尾段的腹外侧区和内侧区腹侧部。中段的双标细胞占全部双标细胞数的57％,尾段占41％,吻段占2％。在背中缝核(DR)内,亦可见到一些双标细胞。PAG内的双标细胞占其HRP标记细胞总数的37％,但仅占5-HT样阳性细胞总数的4.5％。标记细胞主要为中型(20—30μm)梭形及三角形,小型(<20μm)梭形和大型(>30μm)多角形细胞较少见。     

猫骶髓“内脏面”L-ENK样神经元的分布和定位投射

应用免疫组织化学和HRP与免疫组织化学双重标记的方法,对骶髓“内脏面”L-ENK样神经元的分布及其与副交感节前神经元和向臂旁外侧核及Barrington核投射的二级传入神经元的关系进行了研究。L-ENK样神经元分布于整个“内脏面”上,尤以中间带外侧核和后连合核为密集。在中间带外侧核内,L-ENK样神经元的分布与向盆神经注入HRP后逆行标记的副交感节前神经元的分布位置重叠,能明显地划分为背侧带和外侧带。在Onuf核及其与骶髓副交感核之间的联系细胞桥上首次发现有L-ENK样神经元存在。将HRP注入盆神经结合L-ENK免疫组织化学反应,在骶髓副交感核外侧带和背侧带均发现大量HRP/L-ENK双标细胞。几乎全部HRP标记细胞均为HRP/L-ENK双标细胞,个别双标细胞出现于中间带外侧核的中间带(interband)内。将HRP注入臂旁外侧核或Barrington核结合L-ENK样免疫组织化学反应,在“内脏面”的中间带外侧核、中介核和后连合核处都发现HRP/L-ENK样双标细胞。上述结果证明猫骶髓“内脏面”、Onuf核及联系细胞桥上均有L-ENK样神经元分布,其中“内脏面”向臂旁外侧核或Barrington核投射的二级神经元有一部分含有L-ENK样活性物质,骶髓副交感核的外侧带、背侧带和中间带均有L-ENK样副交感节前神经元。     

猫上丘向大中缝核及其邻近网状结构(巨细胞网状核、尾侧脑桥网状核)的投射

将辣根过氧化物酶注射于9只猫的大中缝核及其一侧邻近网状结构(巨细胞网状核或尾侧脑桥网状核)。各例均在注射部位的对侧上丘的中、深灰层内出现标记细胞,其中以中灰层为主,特别是上丘中部中灰层的外侧部较密集。9例中有5例在注射部位的同侧上丘内也出现极少量标记细胞,它们主要位于上丘外侧部的中、深灰层。标记细胞可分为大、中、小三种,其中大细胞(直径为40微米以上)约占15％左右,其余为中、小细胞。本文还对顶盖网状投射的机能意义进行了讨论。     

盆内脏感觉二级传人通路的研究

向猫盆神经注入10％蓖麻毒素2μl,存活3～5天后,再注射20％HRP溶液于同侧臂旁外侧核,2～3天后多聚甲醛和戊二醛灌注动物及取材。电镜下发现,盆神经初级传入纤维的终末(溃变)与向臂旁外侧核投射的位于骶髓后连合核、中间带外侧核、后角Ⅰ层内的HRP逆行标记神经元,形成轴-树和轴-体突触,从而在超微水平确证了盆内脏感觉传入的二级传导通路起源于骶髓后连合核、中间带外侧核、后角Ⅰ层,投射到臂旁外侧核。     

长翼蝠(Miniopterus Schrebersi)上丘与传递超声信息有关核团的传入联系—HRP法

用HRP逆行追踪法结合电生理学技术,对21只长翼蝠上丘(SC)超声信息的传入联系进行了形态学研究。13只动物上丘的听应部位电泳HRP后,标记神经元恒定地出现于双侧的下丘(IC,同侧为主)和外侧丘系背核(DNLL,对侧占优势)。约半数动物的同侧前外侧橄榄周核(ALPO)存在标记神经元。此外,标记神经元还出现于下列结构中,同侧的舌下神经前置核(n.Ⅻ)、小脑顶核(F)、黑质(SN)、后连合核(NPC)、丘脑(THa)、未定带(ZI),对侧的小脑齿状核(D)、双侧的中脑网状结构(MRF)、上丘(SC)。8只长翼蝠上丘的非听反应部位电泳HRP后,同侧的舌下神经前置核、小脑顶核、黑质、后连合核、丘脑、未定带,对侧的小脑齿状核,双侧的中脑网状结构及上丘亦见标记神经元。本实验提示:上丘的超声信息主要是经过同侧前外側橄榄周核和下丘以及对侧的外侧丘系背核中继传入的。     

猫肾上腺交感神经的来源

本文用HRP逆行标记法对13只猫的肾上腺交感神经元进行了定位研究,结果如下:1.交感神经节前神经元见于同侧脊髓T_2-L_1节段。其中T_7-T_(10)占61.1%。标记细胞大多数(97.4%)位于中间外侧核本部(ILP)。细胞形态,在横面上多呈梭形和卵圆形;在纵断面上,呈梭形.2.标记细胞见于同侧交感干神经节T_4-L_1节段。其中T_8-T_(13)占85.5%。细胞形态以卵圆形、梭形居多。标记细胞在神经节内散在分布。3.腹腔节标记细胞位于同侧半,细胞多为圆形和卵圆形。     

金黄地鼠丘脑网状核视部的纤维联系

本实验采用顺行、逆行及跨神经元追踪技术,对金黄地鼠丘脑网状核视部的纤维联系进行了实验观察。一、正常金黄地鼠4只,制成尼氏和Loyez染色的连续切片各4套,观察丘脑网状核(RT)的正常位置形态和范围。二、将 ~3H-Proline和~3H-Fucose注人动物一侧眼球2只,存活期分别为10、15天)后,可见跨神经元标记于双侧RT的背尾侧部,但同侧标记甚少。三、将HRP分别注入丘脑后外侧核(LP)、外侧膝状体背核(LGd)和外侧膝状体腹核(LGv)(8只,存活期1天)后,分别在同侧RT的背尾侧份的背侧区、中份和腹侧区见有HRP标记神经元。四、将~3H-Proline和~3H-Leucine混合导入视皮质17区不同部位(3只,存活期1天)后,可见在各例的同侧RT的背尾侧部的整个吻尾范围内都有长形的标记点。当注射17区尾侧时,标记部位靠背侧,而注射区越近吻侧时,标记点亦越靠腹侧。五、将HRP注入上丘(6例)时,见RT有极少量标记。本文认为,RT的背尾侧部为核的视部,因为它与视皮质及一些已知的与视觉有关的核团,如后外侧丘脑核、外侧膝状体背核和腹核等都有联系;同时,由于它们之间有局部点对点的定位关系,故此核可能与特定的、有局部定位的视信息的调节有关。     

猫外侧膝状体腹核至上丘和顶盖前区的定位投射——HRP法

本文采用HRP方法观察了猫外侧膝状体腹核至上丘和顶盖前区的定位投射,HRP注射在上丘深层后,可见同侧较吻端的外侧膝状体腹核内侧部腹侧半的许多细胞被标记,这些细胞成团分布,多为圆形或卵圆形。注射在吻端顶盖前区以后,二侧较尾端的外侧膝状体腹核外侧部的细胞被标记,以对侧为主。注射至尾端顶盖前区(部分扩散至上丘)后,同侧较尾端的外侧膝状体腹核外侧部腹侧半的细胞被标记。与注射于上丘者相比,细胞密度较低,亦为圆形或卵圆形,提示外侧膝状体腹核至上丘或顶盖前区的投射具有较明显的局部组构关系。     

Origins of the projections of the superior colliculus to the dorsal lateral geniculate nucleus and the pulvinar in the rabbit

The origins of the projections of the superior colliculus to the dorsal lateral geniculate nucleus and to the pulvinar in Dutch-belted rabbits were investigated using horseradish peroxidase (HRP) methods. Following injections of HRP in the dorsal lateral geniculate nucleus, retrogradely labeled neurons were found in the upper two-thirds of the stratum griseum superficiale of the ipsilateral superior colliculus. Most of the labeled somata were spindle-shaped, and their major axes tended to be perpendicular to the surface of the superior colliculus. In contrast, following injections of the pulvinar, labeled neurons were found in the lower third of the ipsilateral stratum griseum superficiale. In these cases, the labeled somata were larger than those labeled following dorsal lateral geniculate injections and were multipolar in shape.     

Superficial tectal neurons projecting to the dorsolateral pontine nucleus in the rabbit

Summary After WGA-HRP injections in the pontine grey involving the dorsolateral pontine nucleus, a great number of labeled cells were found in the superficial layers of the ipsilateral superior colliculus. The majority of these cells were located in the stratum griseum superficiale (SGS). Few labeled cells were found in the stratum opticum, and the stratum zonale (SZ) showed no labeled cells. Labeled cells in the SGS formed a rather homogeneous population as most of them had fusiform somata with an upper dendritic process which runs vertically to reach the SZ. These cells were mainly located in the middle third of the SGS, forming a sublamina in this layer. These results demonstrate the participation of the superficial tectal layers in the ipsilateral descending pathway of the superior colliculus, allowing visual information to reach precerebellar stations at the dorsolateral pontine nucleus.     

Origins of the pretectal and tectal projections to the central lateral nucleus in the cat

The pretectal and tectal projections to the thalamic intralaminar nuclei in the cat were studied following horseradish peroxidase injections centered in the central lateral nucleus. Retrogradely labeled neurons were found in both the pretectum and the superior colliculus, ipsilateral and, to a lesser extent, controlateral to the injection site. Labeled pretectal neurons were found throughout all pretectal nuclei; the densest concentrations were in the medial pretectal nucleus, the anterior pretectal nucleus and the nucleus of the posterior commissure. The major source of tectal projections were the small neurons in the stratum griseum intermediate.     

Distribution of calbindin, parvalbumin and calretinin in the lateral geniculate nucleus and superior colliculus in Cebus apella monkeys

We studied the distribution of the calcium-binding proteins calbindin, parvalbumin and calretinin, in the superior colliculus and in the lateral geniculate nucleus of Cebus apella, a diurnal New World monkey. In the superior colliculus, these calcium-binding proteins show different distribution patterns throughout the layers. After reaction for calretinin one observes a heavy staining of the neuropil with few labeled cells in superficial layers, a greater number of large and medium-sized cells in the stratum griseum intermediale, and small neurons in deep layers. The reaction for calbindin revealed a strong staining of neuropil with a large number of small and well stained cells, mainly in the upper half of the stratum griseum superficiale. Intermediate layers were more weakly stained and depicted few neurons. There were few immunopositive cells and little neuropil staining in deep layers. The reaction for parvalbumin showed small and medium-sized neurons in the superficial layers, a predominance of large stellate cells in the stratum griseum intermediale, and medium-sized cells in the deep layers. In the lateral geniculate nucleus of Cebus, parvalbumin is found in the cells of both the P and M pathways, whereas calbindin is mainly found in the interlaminar and S layers, which are part of the third visual pathway. Calretinin was only found in cells located in layer S. This pattern is similar to that observed in Macaca, showing that these calcium-binding proteins reveal different components of the parallel visual pathways both in New and Old World monkeys.     

Integration of visual and auditory information in bimodal neurones in the guinea-pig superior colliculus

Summary We have investigated the responses of neurones in the guinea-pig superior colliculus to combinations of visual and auditory stimuli. When these stimuli were presented separately, some of these neurones responded only to one modality, others to both and a few neurones reliably to neither. To bimodal stimulation, many of these neurones exhibited some form of cross-modality interaction, the degree and nature of which depended on the relative timing and location of the two stimuli. Facilitatory and inhibitory interactions were observed and, occasionally, both effects were found in the same neurone at different inter-stimulus intervals. Neurones whose responses to visual stimuli were enhanced by an auditory stimulus were found in the superficial layers. Although visual-enhanced and visual-depressed auditory neurones were found throughout the deep layers, the majority of them were recorded in the stratum griseum profundum. Neurones that responded to both visual and auditory stimuli presented separately and gave enhanced or depressed responses to bimodal stimulation were found throughout the deep layers, but were concentrated in the stratum griseum intermediale and extended into the stratum opticum.     

Laminar origin of ipsilateral tectopontine pathways

The purpose of these experiments was to identify the cells of origin of the ipsilateral tectopontine pathways in the grey squirrel (Sciurus carolinensis). Following injections of tritiated amino acids into individual collicular laminae, labelled fibers could be traced to the dorsolateral pontine nuclei and overlying lateral pontine tegmentum. Fibers originating in stratum griseum superficiale terminated most heavily within the pontine nuclei whereas those arising from stratum griseum profundum terminated most heavily within the tegmentum. After horseradish peroxidase was injected into the dorsolateral pontine nuclei, cells labelled with reaction product were found in all 3 grey laminae of the superior colliculus, but the majority were located in stratum griseum superficiale. In contrast, when horseradish peroxidase was injected into the tectorecipient pontine tegmentum, most of the labelled cells were located in stratum griseum profundum.These results indicate that each of the 3 grey laminae of the superior colliculus projects to both the dorsolateral pontine nuclei and the lateral pontine tegmentum. However, the pathway to the pontine nuclei arises chiefly in stratum griseum superficiale while the tectotegmental pathway arises chiefly in stratum griseum profundum.     

Specific projections of retina transplanted to rat brain

Summary Retinae were taken from fetal rats and transplanted adjacent to the superior colliculus of neonatal rats. After 1 month survival, the transplants were surgically removed from the hosts, locally damaged or injected with horseradish peroxidase (HRP) to determine the distribution of the transplant efferents in the host brains. Histological examination of the transplants revealed cell and plexiform layers characteristic of normal retinae. Since the retinae were undifferentiated at the time of transplantation, this layering developed within the host. The only obvious differences from normal retina were that the layers were organized in rosettes or folded sheets and lacked well developed photoreceptor outer segments. In animals which had lesions or HRP injections confined to the retinal transplant, proper staining of sections of the host brain revealed transplant projections. These projections were confined to the optic tract and nuclei which are normally retinorecipient such as the superior colliculus and dorsal lateral geniculate nucleus. Projections were found along the border of non-retinorecipient nuclei such as the lateral posterior nucleus, but did not appear to enter these nuclei. It was observed that within the superior colliculus the host retinal input had an effect on the distribution of the transplant projection. In one-eyed hosts the transplant projection was distributed throughout the stratum (s.) zonale, s. griseum superficiale, and s. opticum; whereas in the two-eyed hosts, the transplant projection was confined to the s. zonale and the border between s. griseum superficiale and s. opticum.We suggest that a special affinity exists between the axons of the retinal transplants and host visual structures. Furthermore, factors, such as competition and timing may be important in determining the distribution of the transplant axons within the specific target nuclei. Transplantation appears to be a useful technique for further studies on the mechanisms underlying the development of specific neuronal connections.     

Alterations of neuronal activity in the superior colliculus of rotating animals

We have investigated the relationship between alterations in neuronal activity in the superior colliculus and behavioral responses which occur following disruption of basal ganglia circuitry. These changes were analysed following unilateral suppression of the immediate early genes, c-fos and ngfi-a, in the striatum and/or the globus pallidus. Animals with unilateral suppression of immediate early gene expression in the striatum exhibited robust circling activity, following administration of D-amphetamine, that was directed towards the side of suppression. The intensity of rotation was inversely related to the length of the recovery period following antisense infusion and increased significantly when the globus pallidus was infused simultaneously with the striatum. The difference between ipsiversive (towards the antisense-infused hemisphere) and contraversive rotations was calculated and animals were grouped by number according to their ipsiversive bias: I, <50 turns; II, 50-500 turns; III, 500-1000 turns; IV, >1000 turns. Immunohistochemical localization of Fos was used as an indicator of neuronal activity in the superior colliculus. While group I animals showed diffuse Fos-like immunoreactivity throughout the intermediate layers of the superior colliculus, those animals in groups II-IV showed increasing suppression of Fos-like immunoreactivity in the stratum album intermediale and marked enhancement in the stratum griseum intermediale. Correlation and regression analysis revealed a significant positive relationship between the number of ipsiversive rotations and the number of Fos-positive nuclei in the stratum griseum intermediale of the ipsilateral superior colliculus. These data suggest that the degree of rotation elicited in an animal may depend on reciprocal suppression/stimulation of adjacent intermediate strata of the superior colliculus. This study provides the first demonstration, using Fos immunohistochemistry, of changes in tectal activity produced by alterations in basal ganglia function. These findings support previous electrophysiological studies in this region and suggest that the nigrotectal projection may be an important site of altered basal ganglia output.     

Various types of corticotectal neurons of cats as demonstrated by means of retrograde axonal transport of horseradish peroxidase

Summary The retrograde labeling of cortical neurons with horseradish peroxidase (HRP) was used to investigate the morphological features of neurons in various cortical areas projecting to the superior colliculus in the cat.Corticotectal cells were found to be labeled in layer V of the entire cerebral cortex. The number of labeled cells and their locations varied according to the sites of injections of HRP in the colliculus. Most of the Corticotectal cells identified in the present study were small (9–20 m in diameter, 66%) and medium (20–40 urn, 30%) pyramidal neurons and only 4% of them were large (more than 40 m). The labeled cells, 261 in total number, had somal diameters of 20.8±8.0 m (mean and SD). The range of sizes of the labeled neurons was different in different cortical areas. For example, the labeled neurons in the Clare-Bishop area had a greater proportion of large diameter cells than in other areas.The present findings are largely in agreement with the previous data of anterograde degeneration methods with respect to the topographical correlation of the Corticotectal projections. However, in some cortical areas, e.g., the sensorimotor and the first visual (area 17) cortex of the lateral surface of the hemisphere, relatively small numbers of Corticotectal neurons appear to have been labeled by retrogradely transported HRP. The sparsity of the labeled neurons in certain cortical areas may reflect the existence of Corticotectal neurons with axon collaterals supplying brain structures other than the superior colliculus.Abbreviations A.c. Aqueductus cerebri - AEct Gyrus ectosylvius anterior - AEs Sulcus ectosylvius anterior - AI Stratum album intermediale - AL Gyrus lateralis anterior - AP Stratum album profundum - AS Gyrus sylvius anterior - Cd Nucleus caudatus - F.l.m. Fasciculus longitudinalis medialis - GI Stratum griseum intermediale - GP Stratum griseum profundum - GS Stratum griseum superficiale - Ic Inferior colliculus - L Left - MEct Gyrus ectosylvius medius - MS Gyrus sylvius medius - MSup Gyrus suprasylvius medius - N.r. Nucleus ruber - O Stratum opticum - P Pontine nuclei - P.c. Pedunculus cerebri - PEct Gyrus ectosylvius posterior - P.g. Periaqueductal gray matter - PSigm Gyrus sigmoideus posterior - PSup Gyrus suprasylvius posterior - R Right - Sc Superior colliculus - S.n. Substantia nigra - Z Statum zonale - II Optic nerve - III and IV Motor nuclei of cranial nerves     

金黄地鼠上丘和外侧膝状体之间的联系

本实验采用了顺行和逆行追踪技术,对金黄地鼠上丘与丘脑视核团的纤维联系进行了实验观察。一、用尼氏和Loyez染色法,对4只正常金黄地鼠上丘和外侧膝状体背核和腹核的正常结构做了观察。二、3~H-亮氨酸和3~H-脯氨酸注入动物上丘不同部位(4只,存活期一天)后,可见神经末梢标记于同侧的外侧膝状体背核和腹核的外侧部位。若注射部位在上丘外侧,其投射部位在外侧膝状体背核和腹核的尾外侧;注射部位移向内侧,投射部位移向吻外侧。三、将HRP注入外侧膝状体背核(4只,存活期一天)或腹核(2只,存活期一天)或后外侧核(2只,存活期一天)后,在同侧上丘浅层见有标记神经元。在上丘深层则未见。本实验说明了上丘浅层的神经元对同侧的外侧膝状体背核和腹核有局部定位的投射,并按视野和视网膜将该投射作定位排列。