大鼠中缝大核下行投射纤维与三叉神经脊束核尾侧亚核向丘脑投射神经元之间的突触联系  

SYNAPTIC CONNECTIONS BETWEEN DESCENDING PROJECTION FIBERS FROM NUCLEUS RAPHE MAGNUS AND NEURONS IN CAUDAL SUBNUCLEUS OF THE SPINAL TRIGEMINAL NUCLEUS PROJECTING TO THE THALAMUS IN THE RAT

作　　者：李云庆[1] 李金莲[1] 

机构地区：[1]第四军医大学基础医学部解剖学教研室,西安710032

出　　处：《神经解剖学杂志》1999年第3期217-221,共5页Chinese Journal of Neuroanatomy

基　　金：国家杰出青年科学基金

摘　　要：本研究分别用逆行和顺行追踪相结合及逆行追踪与免疫组织化学反应相结合的双标记技术对中缝大核下行投射纤维和５ＨＴ 样阳性终末在三叉神经脊束核尾侧亚核内的分布及其与向丘脑投射神经元之间的突触联系进行了观察。将ＨＲＰ注入丘脑腹后内侧核，证明ＨＲＰ逆标神经元主要见于三叉神经脊束核尾侧亚核的Ⅰ、Ⅲ层；将顺行标记物ＰＨＡＬ 注入中缝大核，证明ＰＨＡＬ顺标纤维和终末也主要见于尾侧亚核的Ⅰ层，Ⅱ层内仅有少量ＰＨＡＬ 顺标终末；免疫组织化学反应的结果显示５ＨＴ 样阳性终末也主要存在于尾侧亚核的Ⅰ和Ⅱ层，其它部位仅散在分布。在电镜下观察到：（１）三叉神经脊束核尾侧亚核Ⅰ层的ＨＲＰ逆标神经元的胞体和树突分别与ＰＨＡＬ顺标终末形成轴体突触和轴树突触，其中大部分为对称性突触，非对称性突触较少；（２）尾侧亚核Ⅰ层ＨＲＰ逆标神经元的胞体和树突也分别与５ＨＴ 样阳性终末形成轴体突触和轴树突触，这些突触联系也以对称性突触为主。本研究的结果表明：中缝大核的下行投射纤维主要终止于三叉神经脊束核尾侧亚核Ⅰ层，对此层内向丘脑投射的神经元可能主要发挥抑制作用，而５ＨＴ 是中缝大核下行投射纤维的主要神经活性物质。In order to investigate the distributions of descending projection fibers from the nucleus raphe magnus(NRM) and 5 hydroxytryptamine like immunoreactive(5 HT LI) terminals in the caudal subnucleus of the spinal trigeminal nucleus(Vc) and synaptic connections between the descending projection fibers from NRM and the neurons in Vc projecting to the thalamus, the double labeling methods by combination of horseradish peroxidase(HRP) retrograde tracing with phaseolus vulgaris leucoagglutinin(PHA L) anterograde tracing or by combination of HRP retrograde tracing with immunohistochemical staining for 5 HT were used in the present study. After injecting HRP into the thalamic ventral posteromedial nucleus(VPM), most of the HRP retrogradely labeled neurons were found in the marginal layer(lamina Ⅰ) and magnocellular layer(lamina Ⅲ) of the Vc. After injecting PHA L into the NRM, PHA L anterogradely labeled fibers and terminals were most frequently encountered in lamina Ⅰ. Only a few PHA L anterogradely labeled fibers and terminals were sparsely observed in the substantia gelatinosa(lamina Ⅱ). 5 HT LI fibers and terminals were densely found in laminae Ⅰ and Ⅱ, and they were also scattered in the deeper laminae. Under the electron microscope, the following synaptic connections in the Vc were observed: (1) PHA L labeled terminals made axo dendritic and axo somatic synapses with the dendrites and somata of HRP labeled neurons in laminae Ⅰ, Ⅲ of the Vc. (2) 5 HT LI terminals formed axo dendritic and axo somatic synapses with the dendrites and somata of HRP labeled neurons in laminae Ⅰ, Ⅲ of the Vc. (3) PHA L labeled terminals or 5 HT LI terminals made axo dendirtic and axo somatic synapses with dendrites and somata of the non labeled neurons in laminae Ⅰ, Ⅲ of the Vc. (4) In lamina Ⅱ, only axo dendritic and axo somatic synapses formed by PHA L labeled terminals or 5 HT LI terminals and dendrites and somata of the non labeled neurons were observed. Most of those synaptic co

关 键 词：5-羟色胺 突触联系 中缝大核 三叉神经 脊束核 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学]