黄雀(carduelis spinus)耳蜗神经元至延髓耳蜗主核的投射——HRP法研究

将HRP溶液注入鸣禽黄雀的耳蜗内,顺行追踪了耳蜗神经元至延髓听觉核团的上行投射。①在同侧的听神经(NⅧ)有密集标记的神经纤维束并分别投射至延髓的巨细胞杉和角状核;②在巨细胞核和角状核出现大量密集的标记终末,表明:黄雀的耳蜗神经元发出的纤维组成听神经后分别投射至同侧的巨细胞核和角状核做为听觉通路的第一级换元站的延髓耳蜗主核只由此二亚核组成,延髓的层状核并不接受耳蜗纤维的直接投射。     

黄喉鹀耳蜗核的传出投射

用HRP顺行追踪方法,研究黄喉鵐(emberiza elegans)的两对耳蜗核,即角状核和巨细胞核的传出投射.将HRP注入角状核,在双侧上橄榄核,对侧外侧丘系核腹侧部,外侧丘系腹核及中脑背外侧核的背侧1/4的区域见到顺行标记纤维或终末.将HRP注入巨细胞核,标记纤维或终末分布于双侧层状核;标记细胞分布于同侧上橄榄核.结果表明:角状核投射至双侧上橄榄核,对侧外侧丘系核腹侧部,外侧丘系腹核及中脑背外侧核的背侧部.巨细胞核投射至双侧层状核.此外,巨细胞核接受同侧上橄榄核的传人,它可能是一条听觉的反馈回路.     

黄喉鹀层状核向脑桥及中脑听性核团的投射

用HRP顺行追踪法研究黄喉鵐延髓层状核向脑桥及中脑的投射.将HRP微电泳入层状核,在同侧上橄榄核,对侧脑桥外侧丘系腹核及中脑背外侧核等处见到密集的顺行标记纤维或终末;在对侧层状核同时见到许多标记细胞和终末;在双侧巨细胞核出现了密布的逆行标记细胞.结果说明层状核投射至同侧上橄榄核,并终止于对侧的外侧丘系腹核及中脑背外侧核;双侧层状核之间有许多的往返联系.此外,层状核接受巨细胞核的传入投射.因此层状核可能是听觉上行通路中在脑干的第二级中继站.     

黄雀延髓层状核的传出纤维联系──HRP法研究

向４２只黄雀的延髓展状核加压注入或微电泳泳入ＨＲＰ后，在同侧的脑桥上橄榄核、对侧的脑桥外侧丘系腹核及中脑外侧核背侧部内见到密集的顺行标记终末或纤维；在双侧的延髓巨细胞核出现了大量的逆行标记细胞；在对侧的层状核内既有密集的标记终末又有一些标记细胞．结果表明：层状核的传出纤维投射到同侧上橄榄核，经外侧丘系走行至对侧的外侧丘系腹核和中脑外侧核背侧部，双侧的层状核之间也有交互投射。此外，层状核接受耳蜗亚核──双侧巨细胞核的传入投射．因此，层状核是听觉上行通路中的第二级中继站．     

白眉 （Emberiza tristrami Swinhoe）听觉中继核团上橄榄核的神经联系──HRP法研究

采用ＨＲＰ顺逆行示踪技术对白眉　延脑听觉中继核团上橄榄核的纤维联系进行了研究。结果表明：上橄榄核接受双侧角状核的传入投射，并发出纤维上行投射至双侧外侧丘系核和中脑背外侧核。上橄榄核与角状核的联系以同侧为主，与外侧丘系核的联系以对侧为主。上橄榄核还发出纤维下行投射至巨细胞核。双侧上橄榄核之间还存在着交叉投射。     

白眉Wu（Emberiza tristrami Swinhoe）听觉中继核团上橄榄核的…

采用ＨＲＰ顺逆行示踪技术对白眉Ｗｕ延脑听觉中继核团上橄榄核的纤维联系进行了研究。结果表明：上橄榄核接受双侧角状核的传入投射，并发出纤维上行投射至双侧外丘系核和中脑背外侧核。上橄榄核与角状核的联系以同侧为主，与外侧丘系统的联系以对侧为主。上橄榄核还发出纤维下行投射至巨细胞核。双侧上橄榄核之间还存在着交叉投射。     

百灵鸟新纹状体前部巨细胞核向原纹状体栎核的投射

用CB-HRP法研究百灵鸟端脑新纹状体前部巨细胞核的纤维联系.将CB-HRP注入巨细胞核的外侧部,在同侧上丘脑背外侧核的内侧部和外侧部两个亚核及双侧脑桥蓝斑内有密布的逆行标记细胞,在同侧原纹状体栎核有密集的顺行标记终末.将CB-HRP注入巨细胞核的内侧部,在双侧蓝斑亦有标记细胞,在同侧上纹状体腹侧尾核有标记终末.结果表明:巨细胞核的外侧部接受上丘脑背外侧核及蓝斑的传入,它的纤维向发声控制的主要运动中枢-原纹状体栎核投射.巨细胞核的内侧部亦接受蓝斑的传入,它的纤维向发声控制的高位中枢-上纹状体腹侧尾核投射.提示巨细胞核可能参与发声控制及发声学习与记忆等功能.     

黄喉鹀听觉通路的研究——中脑外侧核背部的中枢联系

向黄喉鹀一侧中脑外侧核背侧部微电泳导入HRP后.在同侧脑桥外侧丘系腹核,外侧丘系核腹侧部,对侧上橄榄核,延髓层状核及角状核等处见到逆标细胞,在同侧丘脑卵圆核及卵圆核腹内侧部脑桥外侧丘系腹核出现了标记终末,在对侧中脑外侧核背侧部有密布的标记细胞及终末.结果表明:中脑外侧核背侧部接受脑桥外侧丘系核复合体的外侧丘系核腹侧部及上橄榄核、延髓层状核及NA的传入投射,MLd的纤维传出投射至丘脑的卵圆核及卵圆核腹内侧部,双侧中脑外侧核背侧部之间有往返联系.     

黄雀耳蜗核的传出投射与比较

<正> 作者以前曾证实黄雀(Carduelis splnus)的耳蜗核由巨细胞核(Nucleus magnocellularis,NM)和角状核(Nucleus angularis,NA)组成,耳蜗纤维组成听神经后投射至NM和NA,它们是听觉传入通路在脑内的第一级换元站。NM和NA的传入来源既有相同之处,又有不同。它们的传出投射是否有差别?本研究将49只黄雀分成两组,在鸟头定位仪上,分别向NM和NA微电泳30%HRP溶液,其中局限于NM者15例和NA者19例。动物存活     

豚鼠延髓网状巨细胞核传入联系——HRP逆行标记法

应用HRP技术,将HRP注入豚鼠延髓网状巨细胞核,追踪其传入纤维的起源。HRP注入延髓网状巨细胞核及其腹侧部后,大量标记细胞出现在大脑皮层运动感觉区、上丘、小脑顶核及脊髓颈、胸、腰段灰质。此外在中脑、脑桥、延髓网状结构,前庭内侧核,蓝斑及其腹侧部也出现了标记细胞。当将HRP微电泳至延髓网状巨细胞核以后,标记细胞数量明显减少,但在运动感觉皮层、上丘、小脑顶核、前庭内侧核、颈髓灰质和中脑、脑桥、延髓网状结构仍出现标记细胞,然而在蓝斑及其腹侧部以及脊髓胸、腰段灰质未见有标记细胞。本文就延髓网状巨细胞核与运动、痛觉、睡眠等的关系进行了探讨。     

Demonstration of anterograde labeling of primary auditory projections following intracochlear injections of horseradish peroxidase in the guinea pig

Intracochlear injections of horseradish peroxidase (HRP) were used to map eighth nerve fiber projections from the cochlea to cochlear nucleus complex. Projection patterns revealed by HRP were identical to those previously demonstrated by intracochlear injections of tritiated amino acids known to be axoplasmic transport-dependent. These findings provide evidence in the auditory system for anterograde or transganglionic transport of HRP demonstrated for other sensory neurons.     

The distribution of primary afferents to the cochlear nuclei in the domestic hen (Gallus domesticus).

The normal anatomy of the three cochlear nuclei in the hen, the nucleus laminaris, the nucleus angularis and the nucleus magnocellularis is described. Following lesions of the cochlear nerve, all three nuclei are shown to receive primary cochlear fibers (silver impregnation methods). The part of nucleus laminaris which consists of a ventral convex sheet of cells is shown to receive cochlear nerve fibers from both ears, the nerve fibers from the ipsilateral ear terminating dorsal to the cell sheet while contralateral nerve fibers terminate ventral to the nerve cells. The cochlear ganglion cells projecting to the nucleus laminaris are apparently situated in other parts of the ganglion that the cells projecting to the nucleus angularis and magnocellularis. The findings are discussed in the light of known data on the organization and function of the cochlear nuclei in birds.     

Dual populations of efferent and afferent cochlear axons in the chicken

Cell bodies, dendrites, and axons associated with the cochlear nerve were labelled by injections of horeseradish peroxidase into the inner ear of the chicken. Efferent cochlear neurons, labelled by retrograde axonal transport, were located bilaterally in the ventral medulla, lateral to the abducens nerve root and ventromedial to the superior olive. These cells are characterized by radiate or elongate dendritic morphology. The axons of the efferent neurons extend dorsally adjacent to the abducens nerve root. Those from the contralateral side cross beneath the ventricle and exit, with the ipsilateral efferent fibers, through the vestibular nerve. In the basilar papilla thin, varicose efferent fibers form large, claw-shaped endings on short hair cells and small boutons terminaux on tall hair cells. Afferent components of the cochlear nerve were labelled by anterograde transport. Diffusely-filled cochlear afferents bifurcate in the dorsolateral medulla and send branches to the cochlear nuclei, nucleus angularis and nucleus magnocellularis. In nucleus magnocellularis the primary afferents are of two types. Most are thick and smooth and terminate as end-bulbs of Held; other, relatively thin axons have preterminal and terminal enlargements.We conclude that the brain stem and peripheral auditory system of the bird provide an opportune model for hearing research, which can be compared with that of the mammal. This conclusion is based on the following similarities between the avian and mammalian auditory systems. (1) There are two different types of hair cells with different patterns of efferent and afferent innervation. (2) There are crossed and uncrossed efferent cochlear bundles. (3) There are at least two morphologically distinct types of cochlear efferent neurons and at least two different kinds of afferents.     

黄眉鹀(Emberiza Chrysophrys)端脑发声控制核团的传入投射——HRP法研究

本文用HRP顺、逆行追踪方法,研究了黄眉鹀端脑发声控制中枢-上纹状体腹侧尾核及古纹状体粗核的传入投射。将HRP微电泳入上纹状体腹侧尾核,在同侧新纹状体前部巨细胞核的内侧部、新纹状体中部界面核、端脑听区-Field L、丘脑Uvacformis核及脑桥蓝斑等处见到密布的标记细胞,在古纹状体粗核及嗅叶的X区等处出现了密集成簇的标记终末。将HRP微电泳入古纹状体粗核,逆行标记细胞分布于同侧上纹状体腹侧尾核、新纹状体前部巨细胞核的外侧部、古纹状体带核及蓝斑等处。上述结果表明,上纹状体腹侧尾核接受新纹状体的前部巨细胞核内侧部、新纹状体中部界面核、端脑听区-Field L、丘脑Uvacformis核及脑桥蓝斑的传入投射。新纹状体前部巨细胞核、新纹状体中部界面核和Uvacformis核是参与发声学习与记忆的核团,L区是听觉的最高位中枢,蓝斑与植物性以及情绪性反应有关。提示上纹状体腹侧尾核也参与发声学习、听觉记忆以及植物性、情绪性反应的调节。古纹状体粗核接受上纹状体腹侧尾核、新纹状体前部巨细胞核外侧部、古纹状体带核及蓝斑的传入投射。     

黑尾蜡嘴雀上纹状体控制发声核团的纤维联系

用ＨＲＰ顺、逆行追踪法赤尾蜡嘴雀上纹状体腹侧尾端核的神经联系。结果表明：上纹状体腹侧尾端核分别接受同侧的新纹状体前部巨细胞核、新纹状体中部界面核、丘脑Ｕｖａ核及脑桥蓝斑核的传入投射；它的传出纤维射至同侧的古纹状体粗核及嗅叶的Ｘ区。此外，上纹状体侧尾端核还接受同侧端脑听区的传入投射。因此，发声与听觉的高位中枢有直接的纤维联系。     

Development of functional synaptic connections in the auditory system visualized with optical recording: afferent-evoked activity is present from early stages

A comprehensive survey of auditory network formation was performed in the brain stem of the chicken embryo using voltage-sensitive dye recording. Intact medulla/brain stem preparations with the auditory branch of the eighth nerve attached were dissected from 5.5- to 8-day chicken embryos, and responses evoked by nerve stimulation were recorded optically. In the medulla of 7- and 8-day embryos, we identified four response areas, corresponding to ipsilateral Nucleus magnocellularis (NM) and Nucleus angularis (NA), which receive the auditory afferents, and ipsi- and contralateral Nucleus laminaris (NL), which receive projections from NM. The optical responses consisted of a fast spikelike signal followed by a long-lasting slow signal, which reflected the sodium-dependent action potential and glutamatergic excitatory postsynaptic potential (EPSP), respectively. In NM, NA, and NL, the EPSP-related slow optical signals were detected from some 6-day and all 7- and 8-day preparations, indicating that functional synaptic connectivity in these nuclei arises by the 7-day stage. In the pons of 7- and 8-day embryos, we identified two additional response areas, which evidently correspond to ipsi- and contralateral Nucleus lemnisci lateralis (NLL), the higher-order nuclei of the auditory pathway. Furthermore, we detected optical responses from the contralateral cerebellum, which possibly correspond to transient projections observed only during embryogenesis. The present study demonstrates that functional auditory circuits are established in the chicken embryo at stages earlier than previously reported. We discuss the possible role of afferent-evoked activity with reference to auditory neural network formation.     

无尾两栖类蟾蜍和鸣禽锡嘴雀听觉中枢及其神经通赂的比较研究

本研究采用HRP示踪技术对无尾两栖类蟾蜍（Bufogargarizans）和鸣禽锡嘴雀（Ooccothraustescoccothraustes）从外周到听觉中枢的通路逐级进行了追踪比较研究.结果表明（1）无尾两栖类内耳囊听觉神经纤维上行投射到延髓同侧的背侧前庭核,它是听觉上行通路的第一级中枢,由此核中继后再投射到上橄榄核．以对侧为主;上橄榄核再发出纤维投射到中脑同侧的半环隆枕,后者是第三级中枢,此结果说明：无尾两栖类从外周到中脑听觉中枢的神经通路已较完整地形成;（2）鸣禽锡嘴雀的耳蜗听神经上行投射到听觉通路的第一级中队即延脑同侧的前庭外则核和角核,角核又发出纤维通过外侧丘系直接投射到对侧的中脑背外侧核．说明鸣禽鸟除了具备两栖类的听觉中枢及神经通路外．已进化形成独特的听觉神经通路即延脑的角核至中脑的背外侧核。