大鼠延髓和脊髓背角的PKCγ阳性神经元向丘脑胶状核投射

目的 :观察大鼠延髓和脊髓背角内蛋白激酶Cγ亚单位 (PKCγ)阳性神经元向丘脑胶状核的投射。方法 :荧光金 (FG)逆行追踪与PKCγ免疫荧光组织化学染色相结合的双标记技术。结果 :PKCγ阳性神经元主要分布于大鼠延髓和脊髓背角的II层内侧部及II、III层交界处 :将FG注入丘脑胶状核后 ,在延髓背角的I、III层和脊髓背角的I、III、V层及外侧脊核内可见FG标记神经元 ;延髓和脊髓背角I层的部分FG标记神经元呈PKCγ阳性。结论 :大鼠延髓和脊髓背角的PKCγ阳性神经元向丘脑胶状核投射 ,它们可能参与将伤害性刺激信息向丘脑的传递。     

大鼠孤束核内儿茶酚胺能神经元接受面口部深层组织伤害性信息并向臂旁核投射的形态学研究

为了探讨孤束核(NTS)内儿茶酚胺能神经元是否与面口部深层组织的伤害性信息有关并向臂旁核投射,本研究运用荧光金(FG))逆行追踪,福尔马林刺激咬肌和免疫荧光技术相结合的三重标记方法,在荧光显微镜下观察了大鼠NTS内酪氨酸羟化酶(TH)阳性并表达FOS蛋白的神经元向臂旁核的投射。将2％FG注入一侧臂旁外侧核后,向同侧咬肌内注射2％福尔马林溶液,并行TH和FOS免疫荧光组织化学染色,荧光显微镜下在同侧NTS内的连合、内侧、中间内侧和腹侧亚核中可见重叠分布的FG、FOS、TH单标神经元以及FG／TH、FOS／TH、FOS／FG双标和FG／FOS／TH三标神经元。FG／TH和FOS／TH双标神经元分别占同侧NTS内TH阳性神经元总数的28.6％和34.8％;FOS／FG双标神经元占同侧FG逆标神经元总数的26.4％;FG／FOS／TH三标神经元分别占同侧TH阳性神经元和FG逆标神经元总数的23.7％和8.4％。本结果提示大鼠NTS中的部分儿茶酚胺能神经元接受面口部深层组织的伤害性信息并向臂旁外侧核传递。     

脑干神经元向前扣带回皮质中部区域的投射(英文)

目的:用逆行标记方法观察脑干神经元向皮质扣带回中部(the middle portion of the cingulate cortex,MCC)的纤维投射。方法:立体定位注射法将0.06~0.08μl的4%荧光金(Fluoro-gold,FG)注射至MCC(Bregmma:+0.2,-0.3,-0.8 mm)部位,7 d后处死大鼠,含4%多聚甲醛的磷酸缓冲液(PB)灌注固定,取脑组织,制作30μm厚度的冰冻切片,荧光显微镜下观察FG逆行标记神经元的定位分布并计数。结果:MCC与皮质间有广泛的联系,包括与同侧、对侧和扣带回内部的联系。在脑干中缝核簇、蓝斑、被盖腹侧区、被盖背内侧区及中脑中央灰质(α部)均可观察到FG逆标神经元的分布,以上FG标记神经元以同侧为主,对侧较少。结论:以上核团向MCC的投射表明MCC接受来自脑干神经元的广泛投射,提示MCC神经元的活动受到脑干众多结构的调控。     

大鼠脊髓背角向丘脑和外侧臂旁核的神经降压素能投射

本研究应用荧光金(FG)逆行追踪结合神经降压素(NT)免疫荧光组织化学染色的双标记技术,观察了大鼠脊髓背角向丘脑(TH)和外侧臂旁核(LPb)的NT能投射。将FG注入一侧TH或LPb后,FG逆标神经元主要见于脊髓背角的I层;NT阳性神经元主要分布于脊髓背角的I层、II层外侧部及II层内侧部与III层交界处;脊髓背角I层内可观察到FG逆标记并呈NT阳性的双标记神经元。上述结果表明脊髓背角I层的NT阳性神经元向TH和LPb投射,提示脊髓背角I层内的NT阳性神经元可能向TH和LPb传递伤害性信息。     

大鼠三叉神经脊束间质核内接受内脏伤害性信息的含CB神经元向孤束核的投射

目的 探讨大鼠三叉神经脊束间质核(INV)内接受内脏伤害性信息的含calbindin D-28K(CB)神经元与孤束核(NTS)的投射联系。方法 用福尔马林刺激上消化道，应用荧光金(FG)逆行束路追踪结合Fos和CB的免疫荧光组织化学三重标记法。结果 INV的背侧边缘旁核(PaMd)和三叉旁核(PaV)内可见到大量FG逆标细胞，以注射FG的同侧为主。大部分FG逆标细胞(约71.2％)为CB免疫反应阳性。部分FG和CB双标记神经元(约31．5％)同时呈Fos免疫反应阳性的三重标记。结论 INV内部分接受内脏伤害性刺激的CB神经元可直接投射至NTS，含CB的神经元在内脏伤害性信息经INV向NTS的传导通路中，可能发挥重要作用.     

扣带区的传入纤维联系

本文应用HRP法研究扣带区的传入纤维。结果表明扣带区膝前部25、32区接受同侧皮层3、1、2区及苍白球和双侧10、24区、尾壳核、下丘脑外侧核及终纹腔间核的纤维;膝上部(24区)接受同侧皮层32区、丘脑背内侧核外侧部的纤维,接受对侧4区及双侧10区、嗅前核、尾壳核和隔核的纤维;扣带后部(23、29区)接受同侧皮层24、17、18区及中脑吻侧线形核的纤维。扣带区广泛接受皮层、皮质下核、丘脑下部及中脑的传入联系,为解释其生理机能提供形态学依据。     

饥饿促进嗅觉探索与梨状皮层神经细胞反应

目的:对嗅觉的处理和整合是形成嗅觉记忆的关键,本研究观察了饥饿状态下大鼠嗅觉探索行为变化和梨状皮层神经细胞活化的关系。方法:大鼠禁食48 h,嗅球注射荧光金,通过食物埋藏,检测大鼠嗅觉探索行为的变化。利用连续冠状切片,检测梨状皮层前部FG阳性细胞的数量,利用c-fos免疫荧光检测梨状皮层神经细胞活动状态。结果:饥饿促进了大鼠的嗅觉探索效能,梨状皮层FG阳性细胞及c-fos阳性细胞的数量明显高于对照组。结论:饥饿促进嗅觉探索行为和梨状皮层神经细胞活动及嗅球到梨状皮层投射增强有关。     

蒙古种沙土鼠背海马传入纤维的来源

本文应用HRP逆行追踪技术,研究了蒙古种沙土鼠背海马传入纤维的来源。将HRP引入背海马后,在下列各核区发现有HRP标记细胞:1.同侧:内嗅皮层、视前大细胞核;2.双侧(以同侧为主):内侧隔核、斜角带核、上乳头体核、下乳头丘脑束核、兰斑核、中缝核;3.对侧:背海马CA_3、CA_4区。以上结果表明:蒙古种沙土鼠背海马传入来源与大白鼠近似。本文对于背海马传入通路的功能意义进行了探讨。     

大鼠杏仁复合体向听皮层的神经投射

目的：研究大鼠杏仁复合体一听皮层的纤维投射。方法：HRP神经追踪方法结合微电泳技术，以及核黄逆行荧光标记技术。结果：HRP注射到听皮层，同侧杏仁外侧核、杏仁基底核、杏仁前区和杏仁前皮层观察到逆行标记细胞；HRP注射到杏仁外侧核和杏仁基底核，在同侧听皮层出现顺行标记纤维；核黄注入到听皮层，在同侧杏仁外侧核和杏仁基底核发现逆行标记细胞。结论：大鼠听皮层接受同侧杏仁复合体的神经投射。     

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。     

中脑导水管周围灰质、中缝背核、中缝大核和巨细胞网状核α部向孤束核的定位投射

本文用荧光金逆行追踪技术对大鼠下行抑制系统的中脑导水管周围灰质、中缝背核、中缝大核和巨细胞网状核a部向孤束核的投射进行了研究．将荧光金分别注入到孤束核的吻段、中段和尾段后，上述核团内出现的逆行标记神经元分布如下：（1）在冠状切面上，中脑导水管周围灰质内的荧光金标记细胞群集存在；在吻尾方向上呈柱状分布．三个实验组中，除吻段注射组的标记细胞数量少于其它2组外．在分布上完全一致。腹外侧区的标记细胞数量最多，但从尾侧到吻侧逐渐减少；背内侧区的标记细胞数量较少，以中、吻段较多；背外侧区的标记细胞出现于中脑导水管周围灰质的中、尾段，尾段最多，吻段内未见标记细胞．所有实验动物的中脑导水管周围灰质的内侧区均未出现标记细胞．（2）中缝背核内的标记细胞，多数位于其吻段的背侧都与收侧部的移行部，并且以注射区在孤束核的吻段者标记细胞较多；中缝背核的中尾段标记细胞量少，且散在于背外侧部，以注射区在孤束核的中段者标记细胞较多．（3）中缝大核内的标记细胞以核的尾段较多，吻段较少；巨细胞同状核a部内的标记细胞在吻尾方向上分布均匀。此两核团内的标记细胞数量以注射区在孤束核的中、尾段者较多。（4）上述脑区内标记细胞的数量均为注射区的同侧多于对侧。本研     

Auditory cortex projections target the peripheral field representation of primary visual cortex

The purpose of the present study was to identify projections from auditory to visual cortex and their organization. Retrograde tracers were used to identify the sources of auditory cortical projections to primary visual cortex (areas 17 and 18) in adult cats. Two groups of animals were studied. In the first group, large deposits were centered on the lower visual field representation of the vertical meridian located along the area 17 and 18 border. Following tissue processing, characteristic patterns of cell body labeling were identified in extrastriate visual cortex and the visual thalamus (LGN, MIN, & LPl). In auditory cortex, of the four tonotopically-organized regions, neuronal labeling was identified in the supragranular layers of the posterior auditory field (PAF). Little to no labeling was evident in the primary auditory cortex, the anterior auditory field, the ventral posterior auditory field or in the remaining six non-tonotopically organized regions of auditory cortex. In the second group, small deposits were made into the central or peripheral visual field representations of primary visual cortex. Labeled cells were identified in PAF following deposits into regions of primary visual cortex representing peripheral, but not central, visual field representations. Furthermore, a coarse topography was identified in PAF, with neurons projecting to the upper field representation being located in the gyral portion of PAF and neurons projecting to the lower field representation located in the sulcal portion of PAF. Therefore, direct projections can be identified from tonotopically organized auditory cortex to the earliest stages of visual cortical processing.     

Interconnections of the auditory cortical fields of the cat with the cingulate and parahippocampal cortices

Summary The interconnections of the auditory cortex with the parahippocampal and cingulate cortices were studied in the cat. Injections of the anterograde and retrograde tracer WGA-HRP were performed, in different cats (n = 9), in electrophysiologically identified auditory cortical fields. Injections in the posterior zone of the auditory cortex (PAF or at the PAF/AI border) labeled neurons and axonal terminal fields in the cingulate gyrus, mainly in the ventral bank of the splenial sulcus (a region that can be considered as an extension of the cytoarchitectonic area Cg), and posteriorly in the retrosplenial area. Labeling was also present in area 35 of the perirhinal cortex, but it was sparser than in the cingulate gyrus. Following WGA-HRP injection in All, no labeling was found in the cingulate gyrus, but a few neurons and terminals were labeled in area 35. In contrast, no or very sparse labeling was observed in the cingulate and perirhinal cortices after WGA-HRP injections in the anterior zone of the auditory cortex (AI or AAF). A WGA-HRP injection in the cingulate gyrus labeled neurons in the posterior zone of the auditory cortex, between the posterior ectosylvian and the posterior suprasylvian sulci, but none was found more anteriorly in regions corresponding to AI, AAF and AII. The present data indicate the existence of preferential interconnections between the posterior auditory cortex and the limbic system (cingulate and parahippocampal cortices). This specialization of posterior auditory cortical areas can be related to previous observations indicating that the anterior and posterior regions of the auditory cortex differ from each other by their response properties to sounds and their pattern of connectivity with the auditory thalamus and the claustrum.Abbreviations AAF anterior auditory cortical field - aes anterior ectosylvian sulcus - AI primary auditory cortical field - AII secondary auditory cortical field - ALLS anterior-lateral lateral suprasylvian visual area - BF best frequency - C cerebral cortex - CC corpus callosum - CIN cingulate cortex - CL claustrum - DLS dorsal lateral suprasylvian visual area - DP dorsoposterior auditory area - E entorhinal cortex - IC inferior colliculus - LGN lateral geniculate nucleus - LV pars lateralis of the ventral division of the MGB - LVe lateral ventricule - MGB medial geniculate body - OT optic tract - OV pars ovoidea of the ventral division of the MGB - PAF posterior auditory cortical field - pes posterior ectosylvian sulcus - PLLS posterior-lateral lateral suprasylvian visual area - PS posterior suprasylvian visual area - PU putamen - RE reticular complex of thalamus - rs rhinal sulcus - SC superior colliculus - SS suprasylvian sulcus - T temporal auditory cortical field - TMB tetramethylbenzidine - VBX ventrobasal complex of thalamus, external nucleus - VL pars ventrolateralis of the ventral division of the MGB - VLS ventrolateral suprasylvian visual area - VPAF ventroposterior auditory cortical field - WGA-HRP wheat germ agglutinin labeled with horseradish peroxidase - wm white matter     

The nature of the homophone density effect: an ERP study with Chinese spoken monosyllable homophones

We examined in infant rats whether cardiac afferent neurons in the nodose ganglia (NG) express transient receptor potential vanilloid 1 (TRPV1) receptors. Anesthetized rats (9-11 days old) were injected with 2 μl of a fluorescent retrograde tracer (Fluoro-Gold, FG) into the ventricular wall through the anterior epicardial surface. After 2 days, the NG were excised under anesthesia for identification of FG-labeled neurons and immunohistochemical analysis. Of 3858 NG neurons, 5% (202 neurons) were labeled with FG. Among the FG-labeled neurons, 180 (89%) were TRPV1 positive, of which 123 co-expressed 200-kDa neurofilaments (NF200), which is specific for myelinated nerve fibers. Among the FG-labeled neurons that expressed both TRPV1 and NF200, 37 had relatively large cell diameters (>26 μm) (range: 12-38 μm). In conclusion, in infant rats, most cardiac afferent neurons (both myelinated and unmyelinated) in the NG may express TRPV1 receptors. Although functional properties such as those related to the arterial baroreflex may vary among the neurons, our results suggest that, in immature animals, TRPV1 receptors help convey cardiac sensations and control autonomic reflexes.     

Rat posterior parietal cortex: topography of corticocortical and thalamic connections

Anatomical and functional findings support the contention that there is a distinct posterior parietal cortical area (PPC) in the rat, situated between the rostrally adjacent hindlimb sensorimotor area and the caudally adjacent secondary visual areas. The PPC is distinguished from these areas by receiving thalamic afferents from the lateral dorsal (LD), lateral posterior (LP), and posterior (Po) nuclei, in the absence of input from the ventrobasal complex (VB) or dorsal lateral geniculate (DLG) nuclei. Behavioral studies have demonstrated that PPC is involved in spatial orientation and directed attention. In the present study we used fluorescent retrograde axonal tracers primarily to investigate the cortical connections of PPC, in order to determine the organization of the circuitry by which PPC is likely to participate in these functions, and also to determine how the topography of its thalamic connections differs from that of neighboring cortical areas. The cortical connections of PPC involve the ventrolateral (VLO) and medial (MO) orbital areas, medial agranular cortex (area Fr2), portions of somatic sensory areas Par1 and Par2, secondary visual areas Oc2M and Oc2L, auditory area Tel, and retrosplenial cortex. The secondary visual areas Oc2L and Oc2M have cortical connections which are similar to those of PPC, but are restricted within orbital cortex to area VLO, and within area Fr2 to its caudal portion, and do not involve auditory area Te1. The cortical connections of hindlimb cortex are largely restricted to somatic sensory and motor areas. Retrosplenial cortex, which is medially adjacent to PPC, has cortical connections that are prominent with visual cortex, do not involve somatic sensory or auditory cortex, and include the presubiculum. We conclude that PPC is distinguished by its pattern of cortical connections with the somatic sensory, auditory and visual areas, and with areas Fr2, and VLO/MO, in addition to its exclusive thalamic connectivity with LD, LP and Po. Because recent behavioral studies indicate that PPC, Fr2 and VLO are involved in directed attention and spatial learning, we suggest that the interconnections among these three cortical areas represent a major component of the circuitry for these functions in rats.     

Auditory projections to extrastriate visual cortex: connectional basis for multisensory processing in ‘unimodal’ visual neurons

Neurophysiological studies have recently documented multisensory properties in ‘unimodal’ visual neurons of the cat posterolateral lateral suprasylvian (PLLS) cortex, a retinotopically organized area involved in visual motion processing. In this extrastriate visual area, a region has been identified where both visual and auditory stimuli were independently effective in activating neurons (bimodal zone), as well as a second region where visually-evoked activity was significantly facilitated by concurrent auditory stimulation but was unaffected by auditory stimulation alone (subthreshold multisensory region). Given their different distributions, the possible corticocortical connectivity underlying these distinct forms of crossmodal convergence was examined using biotinylated dextran amine (BDA) tracer methods in 21 adult cats. The auditory cortical areas examined included the anterior auditory field (AAF), primary auditory cortex (AI), dorsal zone (DZ), secondary auditory cortex (AII), field of the rostral suprasylvian sulcus (FRS), field anterior ectosylvian sulcus (FAES) and the posterior auditory field (PAF). Of these regions, the DZ, AI, AII, and FAES were found to project to the both the bimodal zone and the subthreshold region of the PLLS. This convergence of crossmodal inputs to the PLLS suggests not only that complex auditory information has access to this region but also that these connections provide the substrate for the different forms (bimodal versus subthreshold) of multisensory processing which may facilitate its functional role in visual motion processing.     

Convergence of unimodal and polymodal sensory input to the entorhinal cortex in the fascicularis monkey

The hippocampal formation is a key structure in memory formation and consolidation. The hippocampus receives information from different cortical and subcortical sources. Cortical information is mostly funneled to the hippocampus through the entorhinal cortex (EC) in a bi-directional way that ultimately ends in the cortex. Retrograde tracing studies in the nonhuman primate indicate that more than two-thirds of the cortical afferents to the EC come from polymodal sensory association areas. Although some evidence for the projection from visual unimodal cortex to the EC exists, inputs from other visual and auditory unimodal association areas, and the possibility of their convergence with polymodal input in the EC remains largely undisclosed. We studied 10 Macaca fascicularis monkeys in which cortical deposits of the anterograde tracer biotinylated dextran-amine were made into different portions of visual and auditory unimodal association cortices in the temporal lobe, and in polymodal association cortex at the upper bank of the superior temporal sulcus. Visual and auditory unimodal as well as polymodal cortical areas projected to the EC. Both visual unimodal and polymodal association cortices presented dense projections, while those from unimodal auditory association cortex were more patchy and less dense. In all instances, the projection distributed in both the superficial and deep layers of the EC. However, while polymodal cortex projected to all layers (including layer I), visual unimodal cortex did not project to layer I, and auditory unimodal cortex projected less densely, scattered through all layers. Topographically, convergence from the three cortical areas studied can be observed in the lateral rostral and lateral caudal subfields. The present study suggests that unimodal and polymodal association cortical inputs converge in the lateral EC, thereby providing the possibility for the integration of complex stimuli for internal representations in declarative memory elaboration.     

The role of anterior ectosylvian cortex in cross-modality orientation and approach behavior

Physiological and behavioral studies in cat have shown that corticotectal influences play important roles in the information-processing capabilities of superior colliculus (SC) neurons. While corticotectal inputs from the anterior ectosylvian sulcus (AES) play a comparatively small role in the unimodal responses of SC neurons, they are particularly important in rendering these neurons capable of integrating information from different sensory modalities (e.g., visual and auditory). The present experiments examined the behavioral consequences of depriving SC neurons of AES inputs, and thereby compromising their ability to integrate visual and auditory information. Selective deactivation of a variety of other cortical areas (posterolateral lateral suprasylvian cortex, PLLS; primary auditory cortex, AI; or primary visual cortex, 17/18) served as controls. Cats were trained in a perimetry device to ignore a brief, low-intensity auditory stimulus but to orient toward and approach a nearthreshold visual stimulus (a light-emitting diode, LED) to obtain food. The LED was presented at different eccentricities either alone (unimodal) or combined with the auditory stimulus (multisensory). Subsequent deactivation of the AES, with focal injections of a local anesthetic, had no effect on responses to unimodal cues regardless of their location. However, it profoundly, though reversibly, altered orientation and approach to multisensory stimuli in contralateral space. The characteristic enhancement of these responses observed when an auditory cue was presented in spatial correspondence with the visual stimulus was significantly degraded. Similarly, the inhibitory effect of a spatially disparate auditory cue was significantly ameliorated. The observed effects were specific to AES deactivation, as similar effects were not obtained with deactivation of PLLS, AI or 17/18, or saline injections into the AES. These observations are consistent with postulates that specific cortical-midbrain interactions are essential for the synthesis of multisensory information in the SC, and for the orientation and localization behaviors that depend on this synthesis.     

一氧化氮合酶在大鼠主盆神经节及阴茎勃起组织中的分布

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