大鼠丘脑背内侧核的传出联系——WGA-HRP法研究

将WGA-HRP微电泳导入19只大鼠的丘脑背内侧核(DM),又将WGA-HRP注射于17只大鼠前额叶皮质的前扣带回背部,前边缘叶和岛叶无颗粒皮质背部,观察DM的传出投射。 DM投射到前额叶皮质的范围广泛,并有一定的局部定位。DM外侧部主要投射到前扣带回背部,其次为中央前区内侧皮质、前边缘叶、岛叶无颗粒皮质背部及腹外侧眶区等。DM内侧部主要投射到岛叶无颗粒皮质背部,其次为前边缘叶、下边缘叶、内侧眶区及腹侧眶区等。DM中间部主要投射到岛叶无颗粒皮质背部。 DM还投射到某些皮质下核团,如丘脑网状核、外侧视前区、尾壳核、伏隔核、苍白球、丘脑下部外侧区及束旁核等。此外,DM和前额叶皮质的前扣带回背部、中央前区内侧皮质、前边缘叶、下边缘叶及岛叶无颗粒皮质背部以及和丘脑网状核、外侧视前区及丘脑下部外侧区之间均有交互投射。     

大鼠间脑和皮质下端脑到前额叶皮质的传入投射——WGA-HRP法研究

本研究将 WGA-HRP 注射于25只大鼠前额叶皮质的前扣带回背部、前边缘区及岛叶无颗粒皮质背部,观察其间脑和皮质下端脑的传入联系。间脑的传入主要来自丘脑背内侧核,并有一定的局部定位。此外,丘脑的板内核群(中央外侧核、旁中央核、中央内侧核及束旁核)、腹侧核群(腹外侧核、腹内侧核、腹前核及腹后核)、中线核群(菱形核、连合核、带旁核及室旁核)、前内侧核、外侧缰核、后核及外侧核亦有到前额叶皮质的传入投射,且投射到前额叶皮质不同部位的数量不同。丘脑下部的传入主要来自外侧区、外侧视前区、尾侧大细胞核及乳头体上核,少量传入也可见于丘脑下部后区、背内侧核、腹内侧核及未定带。皮质下端脑的传入主要来自苍白球,其次为斜角带核、隔核、杏仁核及屏状核。在隔核中,除内侧隔核外还观察到外侧隔核,繖隔核及三角隔核亦投射到前额叶皮质。杏仁核中除杏仁外侧核、杏仁基底核外侧部及内侧部外,还观察到杏仁内侧核及杏仁皮质核亦有少量到前额叶皮质的传入。     

大鼠脑干到前额叶皮质的传入投射——WGA-HRP法研究

用WGA-HRP法研究了25只大鼠前额叶皮质的脑干传入投射。在前扣带回背部、前边缘区及岛叶无颗粒皮质背部注射WGA-HRP后,脑干中的逆行标记细胞大致可分为三类。第一类为单胺类神经元集中的核团,其中蓝斑、腹侧被盖区、黑质致密部、中缝背核、中央上核及尾侧线形核等广泛投射到前额叶皮质各部,而外侧网状核、连合核、中缝大核、A_4、A_5、臂旁核、黑质网状部及颅侧线形核投射到前额叶皮质各部的数量不同。外侧网状核、连合核、中缝大核、A_4、A_5到前额叶皮质的投射文献上尚未见报道。第二类为与眼肌运动有关的核团,如E-W核、导水管周灰质、中脑网状结构及脑桥吻侧网状核。第三类为与感觉有关的核团,如臂旁核、三叉神经感觉主核及连合核。     

大鼠缰核的传入投射——WGA-HRP法研究

将WGA-HRP微电泳于40只大鼠缰核的不同部位,观察其逆行标记细胞分布和将WGA-HRP微电泳于12只大鼠的脚内核、视前区、伞隔核和三角隔核、斜角带核及丘脑下部外侧区等处观察顺行标记终支在缰核中的分布。缰核不同部位的传入来源不同,外侧缰核主要接受脚内核、外侧视前区、斜角带核及丘脑下部外侧区等的传入,可能和纹状体及边缘系统功能有关。内侧缰核主要接受隔核的传入,可能和边缘系统功能有关。外侧缰核还可再分为内侧、外侧两部,内侧缰核也可再分为内侧及外侧两部,它们各接受不同的传入,并可能具有不同的功能。     

大鼠额前皮质的脑干传入纤维联系

用ＣＢ－ＨＲＰ及ＨＲＰ法研究了２７只大鼠额前皮质的脑干传入纤维联系。观察结果发现，额前皮质各区中以岛叶无颗粒皮质胶部接受的脑干传入投射的核团最广泛，且多为植物性神经核；黑质致密部，被盖腹侧区与额前皮质有局部定位的投射关系；脚底视核向额前皮质内侧部投射；脑干中有大量接触脑脊液神经元投射到额前皮质；孤束核可不经其他核团中继直接投射到额前皮质的外侧部。实验对进一步研究额前皮质的功能提供了形态学依据。     

大白鼠丘脑背内侧核的传入纤维联系

用HRP逆行传递法,研究了大白鼠丘脑背内侧核(MD)的传入纤维联系.发现以下核团有细胞发出纤维投射到丘脑背内侧核:额叶皮质、边缘系统(以杏仁核、斜角带和海马为主)、间脑某些核团(主要是丘脑腹侧核、未定带、下丘脑)、中脑(以上丘、脚间核、黑质为主)、脑干网状结构(主要是中脑楔状核)、中缝核群(主要是中缝背核和上中央核)、小脑齿状核和间位核以及蓝斑核。根据丘脑背内侧核的传入纤维联系和有关报道,对该核的整合作用进行了分析。     

大鼠间脑到前额叶皮质的传入投射——FG逆行追踪法

目的：探讨间脑中神经核向前额叶中央外侧区的投射。方法：用荧光金（ＦＧ）逆行追踪法对１５只Ｗｉｓｔａｒ大鼠进行研究。结果：大鼠前额叶中央外侧区接受同侧丘脑前内侧核，丘脑前腹核；丘脑腹内侧核，丘脑腹外侧核，丘脑腹后内侧核，丘脑腹后外侧核；丘脑内侧背核中间部、外侧部、内侧部、丘脑外侧背核；丘脑后核，丘脑外侧一核；丘胲板内核的中央内核的中央内侧核，中央旁核，中央外侧核，丘脑束旁核；丘脑中线核的丘脑带旁核，     

大鼠前庭—丘脑投射——HRP法研究

用 HRP 法研究了41只大鼠的前庭—丘脑投射。在丘脑腹前核(腹外侧核)、腹内侧核、中央外侧核、腹后核、丘脑后核、内侧膝状体大细胞部及外侧膝状体腹侧核等处分别注入 HRP 后,在前庭核簇的不同亚核中观察到标记细胞。证实了大鼠和猫及猴同样也有前庭—丘脑投射。并依前庭—丘脑投射的细胞起源和终止部位不同,可将前庭—丘脑投射大致分为两大类。第一类起自前庭核簇所有四个亚核,投射到丘脑的“非特异”核群,包括腹前核(可能还有腹外侧核),腹内侧核及中央外侧核,可能与维持并改变大脑皮层的兴奋性以及完成运动功能有关。第二类仅起自前庭内侧核和降核,投射到丘脑的腹后核及后核群(包括丘脑后核、内侧膝状体大细胞部及外侧膝状体腹侧核),可能和前庭感觉的传递以及前庭感觉和其它感觉的会聚有关。     

大鼠斜角带核垂直支(VDB)的传入联系

用HRP法研究了VDB的传入联系。结果表明VDB的背、腹侧部均接受下列结构的传入:斜角带核水平支、内侧隔核、扣带皮质、梨状皮质、内嗅皮质、海马、下丘脑外侧核、下丘脑后核、乳头体上核、杏仁内侧核、杏仁皮质核、杏仁基底核内侧及外侧部、室周核、中央灰质腹外侧部、中缝背核、中缝正中核、脚间核、臂旁背侧核、被盖腹侧区及蓝斑。此外,VDB背侧部还接受杏仁外侧核后部、被盖背核的腹侧部及外侧部、嗅前核、未定带及连接核的投射。偶见屏状核投射到VDB背侧部;VDB腹侧部还接受外侧缰核内侧部及杏仁前区的少量投射。     

大鼠额前皮质的丘脑传入纤维联系

实验用ＨＲＰ法研究了２７只大鼠额前皮质的丘脑传入纤维联系。观察结果发现：丘脑背内侧核向额前皮质的投射有局部定位关系，核团的内侧部和中间投射到额前皮质的外侧部，而周边部投射到额前皮质的内侧部；丘脑腹后内侧核小细胞部向额前皮质各区有投射；丘脑至额前皮质的投射为双侧起源，以同侧为主；丘脑与额前皮质之间为往返投射，室旁核，带旁核，胶状核是以接受投射为主，其他核团以发出投射为主。本实验对解释牵涉痛和内脏与躯     

Afferent connections of dorsal and ventral agranular insular cortex in the hamsterMesocricetus auratus

The agranular insular cortex is transitional in location and structure between the ventrally adjacent olfactory allocortex primutivus and dorsally adjacent sensory-motor isocortex. Its ventral anterior division receives major afferent projections from olfactory areas of the limbic system (posterior primary olfactory cortex, posterolateral cortical amygdaloid nucleus and lateral entorhinal cortex) while its dorsal anterior division does so from non-olfactory limbic areas (lateral and basolateral amygdaloid nuclei).The medial segment of the mediodorsal thalamic nucleus projects to both the ventral and dorsal divisions of the agranular insular cortex, to the former from its anterior portion and to the latter from its posterior portion. Other thalamic inputs to the two divisions arise from the gelatinosus, central medial, rhomboid and parafascicular nuclei. The dorsal division, but not the ventral division, receives input from neurons in the lateral hypothalamus and posterior hypothalamus.The medial frontal cortex projects topographically and bilaterally upon both ventral and dorsal anterior insular cortex, to the former from the ventrally located medial orbital and infralimbic areas, to the latter from the dorsally-located anterior cingulate and medial precentral areas, and to both from the intermediately located prelimbic area. Similarly, the ipsilateral posterior agranular insular cortex and perirhinal cortex project in a topographic manner upon the two divisions of the agranular insular cortex.Commissural input to both divisions originates from pyramidal neurons in the respective contralateral homotopical cortical area. In each case, pyramidal neurons in layer V contribute 90% of this projection and 10% arises from layer III pyramidals.In the brainstem, the dorsal raphe nucleus projects to the ventral and dorsal divisions of the agranular insular cortex and the parabrachial nucleus projects to the dorsal division.Based on their cytoarchitecture, pattern of afferent connections and known functional properties, we consider the ventral and dorsal divisions of the agranular insular cortex to be, respectively, periallocortical and proisocortical portions of the limbic cortex.     

Efferent connections of dorsal and ventral agranular insular cortex in the hamster, Mesocricetus auratus

The anterior portion of rodent agranular insular cortex consists of a ventral periallocortical region (AIv) and a dorsal proisocortical region (AId). Each of these two cortical areas has distinct efferent connections, but in certain brain areas their projection fields are partially or wholly overlapping. Bilateral projections to layers I, III and VI of medial frontal cortex originate in the dorsal agranular insular cortex and terminate in the prelimbic, anterior cingulate and medial precentral areas; those originating in ventral agranular insular cortex terminate in the medial orbital, infralimbic and prelimbic areas. The dorsal and ventral regions of the agranular insular cortex project topographically to the ipsilateral cortex bordering the rhinal fissure, which includes the posterior primary olfactory, posterior agranular insular, perirhinal and lateral entorhinal areas. Fibers to these lateral cortical areas were found to travel in a cell-free zone, between cortical layer VI and the claustrum, which corresponds to the extreme capsule. The dorsal and ventral regions send commissural projections to layer I, lamina dissecans and outer layer V, and layer VI of the contralateral homotopical cortex, via the corpus callosum. Projections from the ventral and dorsal regions of the agranular insular cortex to the caudatoputamen are topographically arranged and terminate in finger-like patches. The ventral, but not the dorsal region, projects to the ventral striatum and ventral pallidum. The thalamic projections of the ventral and dorsal regions are largely overlapping, with projections from both to the ipsilateral reticular nucleus and bilaterally to the rhomboid, mediodorsal, gelatinosus and ventromedial nuclei. The heaviest projection is that to the full anteroposterior extent of the medial segment of the mediodorsal nucleus. Brainstem areas receiving projections from the ventral and dorsal regions include the lateral hypothalamus, substantia nigra pars compacta, ventral tegmental area and dorsal raphe nucleus. In addition, the ventral region projects to the periaqueductal gray and the dorsal region projects to the parabrachial and ventral pontine nuclei.These efferent connections largely reciprocate the afferent connections of the ventral and dorsal agranular insular cortex, and provide further support for the concept that these regions are portions of an outer ring of limbic cortex which plays a critical role in the expression of motivated, species-typical behaviors.     

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。     

大鼠上丘的传出投射——ARG法和WGA-HRP法研究

本实验将~3H-Leucine 或 WGA-HRP 定位注(导)入大鼠一侧上丘内,观察了上丘传出纤维的终止部位。上丘浅层的传出纤维下行终止于二叠体旁核(以同侧核的背、腹群为主)、同侧桥核的背外侧部;其上行投射终止于内侧膝状体、膝上核、顶盖前区后核、丘脑外侧后核(以上均为两侧性,以同侧为主)、同侧的内及外侧视束核和外侧膝状体的背侧及腹侧核。另外,在两侧视束和视束交叉处均有标记颗粒。上丘中、深层的传出纤维终止于同侧中央灰质、Darkschewitsch 核、Cajal 中介核、楔形核以及对侧上丘;上行终止于内测膝状体,膝上核、顶盖前区前核、丘脑外侧后核(以上均为两侧性,以同侧为主)、束旁核、未定带、丘脑腹侧核(以上均为同侧);下行终止于同侧的有二叠体旁区和二叠体旁核,桥核的背外侧部、下丘外侧部、桥脑和延髓网状结构、下橄榄核的外侧部;终止于对侧的有二叠体旁核、桥脑和延髓网状结构内侧部、下橄榄核的内侧副核、脊髓颈段前角。     

Neocortical connections in fetal cats

The major extrinsic projections to and from visual and auditory areas of cerebral cortex were examined in fetal cats between 46 and 60 days of gestation (E46-E60) using axonal transport of horseradish peroxidase either alone or in combination with tritiated proline. Projections to visual cortex from the dorsal lateral geniculate nucleus and lateral-posterior/pulvinar complex exist by E46, and those from the contralateral hemisphere, claustrum, putamen, and central lateral nucleus of the thalamus are present by E54-E56. In addition, cells in the medial geniculate nucleus project to auditory cortex by E55. At E54-E56 efferent cortical projections reach the contralateral hemisphere, claustrum, putamen, lateral-posterior/pulvinar complex and reticular nucleus of the thalamus. Cells in visual cortex also project to the dorsal and ventral lateral geniculate nuclei, pretectum, superior colliculus and pontine nuclei, and cells in auditory cortex project to the medial geniculate nucleus. Except for interhemispheric projections, all pathways demonstrated are ipsilateral, and projections linking cerebral cortex with claustrum, dorsal lateral geniculate nucleus and lateral-posterior/pulvinar complex are reciprocal. The reciprocal projections formed with the dorsal lateral geniculate nucleus, lateral-posterior/pulvinar complex and the claustrum show a greater degree of topological organization compared to the projections formed with the contralateral hemisphere and superior colliculus, which show little or no topological order. Therefore, the results of the present study show that the major extrinsic projections of the cat's visual and auditory cortical areas with subcortical structures are present by the eighth week of gestation, and that the origins and terminations of many of these projections are arranged topologically.     

Subcortical projections to the lateral geniculate body in the rat

Summary The subcortical projections to the lateral geniculate body (LGB) in the rat were studied by means of discrete HRP iontophoretic deposits in the dorsal or the ventral LGB; the labelling was compared to that resulting from HRP deposits in neighboring nuclei.After injecting HRP in the dorsal LGB, labelled cells appeared bilaterally in the ventral LGB, pretectum, superior colliculus, lateral groups of the dorsal raphe nucleus and locus coeruleus. Ipsilaterally, labelled cells were found in the lateral posterior thalamus, nucleus of the posterior commissure and deep mesencephalic reticular nucleus.After injecting HRP into the ventral LGB, labelled cells were observed bilaterally in the pretectum, superior colliculus and dorsal raphe nucleus (lateral groups). Contralateral labelling appeared in the ventral LGB and parabigeminal nucleus. Ipsilateral labelling was found in the zona incerta, lateral posterior thalamus, lateral and medial mesencephalic reticular formation, vestibular and dorsal tegmental nuclei.These findings provide evidence of subcortical projections to the LGB arising in visually-related areas as well as extravisual areas, which might be related to the LGB boutons that survive complete cortical and retinal ablations.     

Projections to the rostral reticular thalamic nucleus in the rat

Summary Afferent pathways to the rostral reticular thalamic nucleus (Rt) in the rat were studied using anterograde and retrograde lectin tracing techniques, with sensitive immunocytochemical methods. The analysis was carried out to further investigate previously described subregions of the reticular thalamic nucleus, which are related to subdivisions of the dorsal thalamus, in the paraventricular and midline nuclei and three segments of the mediodorsal thalamic nucleus. Cortical inputs to the rostral reticular nucleus were found from lamina VI of cingulate, orbital and infralimbic cortex. These projected with a clear topography to lateral, intermediate and medial reticular nucleus respectively. Thalamic inputs were found from lateral and central segments of the mediodorsal nucleus to the lateral and intermediate rostral reticular nucleus respectively and heavy paraventricular thalamic inputs were found to the medial reticular nucleus. In the basal forebrain, afferents were found from the vertical and horizontal limbs of the diagonal band, substantia innominata, ventral pallidum and medial globus pallidus. Brainstem projections were identified from ventrolateral periaqueductal grey and adjacent sites in the mesencephalic reticular formation, laterodorsal tegmental nucleus, pedunculopontine nucleus, medial pretectum and ventral tegmental area. The results suggest a general similarity in the organisation of some brainstem Rt afferents in rat and cat, but also show previously unsuspected inputs. Furthermore, there appear to be at least two functional subdivisions of rostral Rt which is reflected by their connections with cortex and thalamus. The studies also extend recent findings that the ventral striatum, via inputs from the paraventricular thalamic nucleus, is included in the circuitry of the rostral Rt, providing further evidence that basal ganglia may function in concert with Rt. Evidence is also outlined with regard to the possibility that rostral Rt plays a significant role in visuomotor functions.Abbreviations ac anterior commissure - aca anterior commissure, anterior - Acb accumbens nucleus - AI agranular insular cortex - AM anteromedial thalamic nucleus - AV anteroventral thalamic nucleus - BST bed nucleus of stria terminalis - Cg cingulate cortex - CG central gray - CL centrolateral thalamic nucleus - CM central medial thalamic nucleus - CPu caudate putamen - DR dorsal raphe nucleus - DTg dorsal tegmental nucleus - EP entopeduncular nucleus - f fornix - Fr2 Frontal cortex, area 2 - G gelatinosus thalamic nucleus - GP globus pallidus - Hb habenula - HDB horizontal limb of diagonal band - IAM interanterodorsal thalamic nucleus - ic internal capsule - INC interstitial nucleus of Cajal - IF interfascicular nucleus - IL infralimbic cortex - IP interpeduncular nucleus - LC locus coeruleus - LDTg laterodorsal tegmental nucleus - LH lateral hypothalamus - LHb lateral habenular nucleus - ll lateral lemniscus - LO lateral orbital cortex - LPB lateral parabrachial nucleus - MD mediodorsal thalamic nucleus - MDL mediodorsal thalamic nucleus, lateral segment - Me5 mesencephalic trigeminal nucleus - MHb medial habenular nucleus - mlf medial longitudinal fasciculus - MnR median raphe nucleus - MO medial orbital cortex - mt mammillothalamic tract - OPT olivary pretectal nucleus - pc posterior commissure - PC paracentral thalamic nucleus - PF parafascicular thalamic nucleus - PPTg pedunculopontine tegmental nucleus - PrC precommissural nucleus - PT paratenial thalamic nucleus - PV paraventricular thalamic nucleus - PVA paraventricular thalamic nucleus, anterior - R red nucleus - Re reuniens thalamic nucleus - RRF retrorubral field - Rt reticular thalamic nucleus - Scp superior cerebellar peduncle - SI substantia innominata - sm stria medullaris - SNR substantia nigra, reticular - st stria terminalis - TT tenia tecta - VL ventrolateral thalamic nucleus - VO ventral orbital cortex - VP ventral pallidum - VPL ventral posterolateral thalamic nucleus - VTA ventral tegmental area - 3 oculomotor nucleus - 3V 3rd ventricle - 4 trochlear nucleus