成年大鼠Pre-Btzinger复合体5-羟色胺样阳性神经纤维与神经激肽1受体样阳性神经元的关系  

RELATIONSHIP BETWEEN 5-HYDROXYTRYPTAMINE IMMUNOREACTIVE NERVE FIBERS AND NEUROKININ-1 RECEPTOR IMMUNOREACTIVE NEURONS IN THE PRE-BTZINGER COMPLEX OF THE ADULT RAT

作　　者：魏晓燕[1] 刘津平[1] 刘莹莹[1] 鞠躬[1] 

机构地区：[1]第四军医大学全军神经科学研究所超微结构研究室,西安710032

出　　处：《神经解剖学杂志》2006年第3期262-266,共5页Chinese Journal of Neuroanatomy

基　　金：国家自然科学基金(No.30470641)资助项目

摘　　要：位于新生和成年哺乳动物延髓腹外侧区的Pre-Bo¨tzinger复合体(pre-Bo¨tzinger complex,PBC)被认为是呼吸节律产生中枢,神经激肽1受体(neurokinin-1receptor,NK1R)是PBC神经元的主要标记物。5-羟色胺(5-hydroxytryptamine,5-HT或seroto-nin)作为一种重要的神经递质,可通过其受体调节呼吸中枢的节律性变化。本研究采用免疫荧光组织化学和免疫电镜双重标记技术,在激光共聚焦显微镜和电子显微镜下观察了大鼠PBC内5-HT样免疫阳性神经纤维与NK1R样免疫阳性神经元或NK1R免疫阴性神经元之间的关系,旨在为5-HT参与PBC神经元呼吸节律的产生和调控提供形态学依据。共聚焦显微镜结果显示:正常大鼠PBC内可观察到一定数量的5-HT样阳性纤维和终末,且有少量的阳性纤维和终末与PBC内NK1R样阳性神经元的胞体或树突形成密切接触。在电镜下可进一步观察到:5-HT样阳性纤维终末可与NK1R样阳性神经元的树突形成直接接触,但未观察到典型的突触联系。5-HT样阳性纤维终末可与NK1R免疫阴性的树突形成非对称性突触。本实验结果提示:5-HT可能通过旁分泌的方式或通过中间神经元间接调节PBC内NK1R样阳性神经元的活动,以实现对中枢呼吸节律的调控。The pre-Bǒtzinger complex （PBC） , located at the ventrolateral medulla, is thought to be the kernel of respiratory rhythmogenesis in mammals. Neurokinin-1 receptor （ NK1 R） has been found to be the marker of the PBC neurons. 5-hydroxytryptamine （5-HT） or serotonin, as an important neurotransmitter, modulates respiratory frequency in the PBC via its receptors. The present study, using immunofluorescence histochemical and immuno - electronic double labeling, aimed to reveal the relationship between 5-HT immunoreactive （ir） nerve fibers and NK1R-ir neurons in the PBC of the adult rat, to provide the morphological basis of 5-HT in participation of respiratory rhythmogenesis and regulation. Under the confocal laser-scanning microseopo, a number of 5-HT-ir fibers and terminals could be found in the PBC. The close appositions between 5-HT-ir fibers and NK1R-ir somas or dendrites could also be detectable, even though much less in amount. Under the electron microscope, 5-HT-ir terminals made direct contacts with NK1R-ir dendrites in the PBC, but no synaptic contact between them was found. However, 5-HT-ir terminals could asymmetrically synapse with NK1R-ir negative dendrites. The present resalts suggest that 5-HT-ir nerve fibers may participate in respiratory rhythmogenesis and regulation through a paracrine effect or volume transmission in the adult rat. 5-HT nerve fibers may also have synaptically function on the interneurons, then turn back to work on PBC neurons.

关 键 词：pre-Bǒtzinger复合体 5-羟色胺 神经激肽1受体 呼吸节律 大鼠 

分 类 号：R329[医药卫生—人体解剖和组织胚胎学]