大鼠杏仁体基底外侧核中DA能与GABA能神经元之间突触关系的免疫电镜研究

目的 了解杏仁体中多巴胺(DA)能神经末梢和7-氨基丁酸(GABA)能神经元之间的相互关系、探索两者在精神分裂症中作用的神经解剖学机制。方法 用免疫电镜双标技术，分别以抗DA和抗谷氨酸脱羧酶(GAD、GABA的合成酶)标记大鼠杏仁体基底外侧核中DA能神经末梢和GABA能神经元，在电镜下观察DA能神经末梢和GABA能神经元之间的突触联系。结果 由DA免疫阳性神经末梢形成的突触中，有43％直接或间接形成于DA免疫阳性神经末梢与GAD免疫反应阳性树突结构之问，其中单一性突触为38％、汇聚性突触为30％、连续性突触为20％、末梢间突触样联系为12％。另外的57％由DA免疫阳性神经末梢与未标记的神经结构形成，其中在未标记的神经元胞体形成10％、树突上82％、轴突末梢上8％。由DA免疫反应阳性末梢形成的所有突触均为对称性即抑制性突触。结论 在大鼠杏仁体基底外侧核中，DA能神经末梢系统以对称性突触支配着GABA能中间神经元，同时，又与核内的谷氨酸能投射神经元形成突触联系．并影响其活动。     

大鼠杏仁体基底外侧核中含D2受体的γ氨基丁酸神经元受多巴胺能末梢支配(英文)

杏仁体中的多巴胺(DA)和γ -氨基丁酸(GABA)递质系统均参与精神分裂症的病理过程,临床上一般用多巴胺II型受体(D2)阻断剂予以治疗。然而,目前尚不清楚GABA与D2受体是否共存,也不清楚DA能神经末梢与GABA能神经元之间的联系方式。本实验用共聚焦激光扫描显微镜(CLSM)和免疫电镜(IEM)研究了杏仁体关键性核团基底外侧核中GABA与D2受体的共存关系以及DA神经能末梢与GABA能神经元之间的突触关系。CLSM显示由谷氨酸脱羧酶(GAD)标记的GABA能神经元全部对D2受体呈免疫阳性反应,表明GABA能神经元含有D2受体。IEM显示,在 980个DA能神经末梢形成的突触中,45%的突触是由DA免疫反应阳性神经末梢直接(36% )或间接(9% )与GAD免疫反应阳性神经元的树突形成,另 55%是由DA免疫反应阳性神经末梢与未标记的神经元成分形成。DA GABA的直接性突触进而可区分为单突触 (16% )、汇聚突触 (14% )及轴 轴突触(6% )。而DA- GABA的间接性突触是个突触复合体。在该复合体中,DA免疫反应阳性末梢在一个未标记的末梢上形成对称性突触,而该未标记末梢又与GAD免疫反应阳性树突形成非对称性突触。在DA与未标记神经元成分之间的突触中,AD免疫反应阳性末梢分别与未标记胞体(4% )、树突(42% )及轴突末梢(9% )形成突触。所有DA突触无一例外均为?     

HRP追踪技术对口虾蛄口胃神经系统的研究

采用神经节离体培养、HRP追踪技术对甲壳动物口虾蛄的口胃神经系统进行了初步研究。分别经侧胃神经、口胃神经和食道下神经对口虾蛄口胃神经系统的口胃神经节、食道神经节和食道旁神经节进行了追踪。经一侧的侧胃神经追踪时,可见大约8个阳性标记神经元位于口胃神经节远端胞体层的腹侧缘,中央神经纤维网也呈较强阳性反应;经口胃神经追踪时,口胃神经节胞体层可见5～6弱阳性标记胞体及阳性标记的神经纤维,食道神经节中可见2个胞体被标记,中央纤维网中也有较强的阳性标记末梢;经一侧食道下神经追踪时,食道神经节胞体层中可见4个阳性标记胞体及部分阳性纤维,而食道旁神经节中仅见阳性标记纤维存在于中央纤维网。以上结果表明:口胃神经节远端腹侧胞体层中的细胞发出突起后以长的分支进入侧胃神经支配胃部的运动,而短的分支则终止于口胃神经节中央纤维网。口胃神经节吻端的细胞突起经口胃神经与食道神经节建立联系。经侧胃神经和口胃神经追踪均未被标记的细胞应属于口胃神经节内的中间神经元。而食道神经节中的部分胞体发出突起进入食道旁神经节的纤维网与中枢神经系统发生联系,另一部分细胞发出突起沿口胃神经进入口胃神经节与此处的神经细胞形成联系,这两类细胞在食道神经节的纤维网中建立联系。     

中缝背核在睡眠-觉醒中的作用

中缝背核(DRN)是调控睡眠-觉醒的重要核团,在脑内有着广泛的神经投射区域。DRN位于中脑导水管腹侧,主要由5-羟色胺(5-HT)、γ氨基T酸(GABA)、多巴胺(DA)和谷氨酸(Glu)能4类神经元构成。本文主要介绍了DRN的各类神经元在睡眠觉醒中相关作用的最新研究进展。     

5-HT_(1A)受体亚型与P物质、Ⅰ型囊泡膜谷氨酸转运体和甘丙肽在大鼠背根神经节神经元中的共表达

为探讨5-HT1A受体亚型参与感觉信息调控的机制,本文利用免疫荧光组织化学双重染色技术观察了该受体亚型与P物质(SP)、I型囊泡膜谷氨酸转运体(VGLUT1)和甘丙肽(Gal)在大鼠背根神经节(DRG)神经元内的共存状况。结果表明:5-HT1A受体亚型阳性神经元占DRG神经元总数的46.2%,阳性神经元以大型及小型神经元为主。在DRG内观察到了5-HT1A/SP、5-HT1A/VGLUT1以及5-HT1A/Gal双标神经元。其中5-HT1A/SP双标神经元占5-HT1A受体亚型阳性神经元的34.6%,占SP阳性神经元的72.0%;5-HT1A/VGLUT1双标神经元占5-HT1A受体亚型阳性神经元的24.1%,占VGLUT1阳性神经元的18.5%;5-HT1A/Gal双标神经元占5-HT1A免疫阳性神经元的17.6%,占Gal免疫阳性神经元的63.8%。5-HT1A/SP和5-HT1A/Gal双标神经元主要为DRG的小型神经元,而5-HT1A/VGLUT1双标神经元主要为大、中型神经元。上述结果提示,5-HT1A受体亚型可能通过调节SP、谷氨酸以及Gal在初级传入终末及外周神经末稍的释放发挥其感觉信息的调节作用。     

大鼠杏仁体基底外侧核GABA和ACh能中间神经元的突触

目的：揭示杏仁体基底外侧核(BL)中的γ-氨基丁酸(GABA)能和乙酰胆碱能(ACh)2种中间神经元树突上的突触联系。方法：用抗GABA和抗胆碱乙酰转移酶(ChAT)抗体对BL做光镜和电镜免疫组化染色。结果：光镜下，GABA免疫反应阳性神经元多为圆形多极神经元；CHAT免疫阳性神经元多为双极神经元。两者数量比约为(7-9)：1。电镜下，支配GABA免疫阳性神经元的突触52．7％为非对称性(兴奋性)，47．3％为对称性(抑制性)，而ChAT免疫阳性神经元则分别为44．9％和55．1％。结论：在情绪性学习记忆的处理过程中，杏仁体GABA能中间神经元起主要的功能作用，可能为抑制作用；而ACh能中间神经元作为辅助的均衡调节作用。     

5-HT及其2A受体在大鼠丘脑前核的表达

目的研究5-羟色胺(5-HT)及其5-羟色胺2A受体(5-HT2AR)在大鼠丘脑前核的表达,探讨两者参与学习记忆的形态学依据。方法免疫组织化学ABC法观察5-HT及5-HT2AR在丘脑前核内的表达情况。包埋前免疫电镜技术观察丘脑前核群的5-HT能投射纤维终末。结果免疫组化结果显示:在大鼠丘脑前核群的前、中、后部均可见阳性的5-HT能神经元及大量串珠状的投射纤维终末,其中背侧核(AD)的神经元着色较深,胞体较大,纤维密集,平均光密度值(A值)与腹侧核(AV)的比较差异显著(P0.05);5-HT阳性反应产物主要定位于胞浆内,胞核不着色。包埋前免疫电镜显示:阳性5-HT能轴突终末与树突形成非对称性的轴-树突触。在AD、AV内可见黄色的5-HT2AR阳性神经元,其中AD的神经元胞体较大,着色较AV深,阳性产物灰度值二者比较差异显著(P0.05);阳性产物主要定位于神经元胞膜,胞核不着色。结论 5-HT和5-HT2AR在大鼠丘脑前核表达,在AD、AV的表达强度不同。     

GAD_(67)-GFP基因敲入小鼠脊髓背角GABA能神经元与不同5-HT受体亚型的共存研究

为初步探讨5-HT受体亚型对脊髓背角内抑制性GABA能神经元的介导作用,本研究以GAD67-GFP基因敲入小鼠为工具,利用免疫荧光双标记方法,检测了5-HT受体亚型与脊髓背角GABA能阳性神经元的共存情况。结果显示,GABA能阳性细胞与5-HT1A,5-HT2A和5-HT3等受体亚型共存,且共存率存在明显不同。以上结果提示5-HT受体各亚型在脊髓水平发挥不同的作用,从而参与完成5-HT复杂的生理效应。     

海马内主要神经递质系统递质释放的异源受体介导作用

海马的主要神经递质包括谷氨酸 (Glu)能、γ-氨基丁酸(GABA)能、乙酰胆碱 (ACh)能、去甲肾上腺素 (NA)能和 5 -羟色胺 (5 - HT)能等系统。这些递质系统神经元的胞体、树突和 /或轴突上存在递质的受体 ,它们介导调节神经递质的释放。这些受体根据其所接受递质来源的不同分为自身受体(autoreceptor)、异源受体 (heteroreceptor)和同源受体 (ho-moreceptor)。自身受体是指接受自身神经元释放的递质的作用而发挥介导作用的受体 ;异源受体系指接受不同类型神经元释放的递质的作用而发挥介导作用的受体 ;同源受体系指接受其它同类型神经元释…     

帕金森病大鼠模型纹状体中谷氨酸、γ-氨基丁酸与多巴胺之间的关系

目的:了解帕金森病大鼠模型纹状体内谷氨酸(glutamate,Glu)、γ-氨基丁酸(gama-aminobutyric acid,GABA)和多巴胺(dopamine,DA)之间的关系,从而进一步探讨帕金森病的发病机制。方法:动物分为溶剂对照组、假手术组和帕金森模型组。大脑右侧黑质致密部和前脑内侧束两点注射6-羟基多巴胺(6-hydroxydopamine,6-OHDA)建立帕金森病大鼠模型,溶剂对照组注入生理盐水,假手术组不注射任何药物,采用脑微透析术于建模后第3,4,5,6周连续动态透析大鼠毁损侧纹状体,结合高效液相色谱(HPLC)动态监测各组谷氨酸、GABA和多巴胺的变化。结果:(1)PD组纹状体内多巴胺含量到第5周仅为溶剂对照组和假手术组的1/5;(2)谷氨酸含量随建模时间逐渐升高,到第6周PD组是溶剂对照组和假手术组的1倍以上;(3)GABA含量呈下降趋势,到第6周约降至溶剂对照组、假手术组的1/2。结论:帕金森病大鼠模型纹状体内谷氨酸的变化与多巴胺分泌可能存在某种联系;GABA含量随建模时间的增加而下降。     

大鼠延髓背角内5-羟色胺、脑啡肽、γ-氨基丁酸、甘氨酸或P-物质能终末与钙结合蛋白阳性神经元间的联系(英文)

CB(calbindin-D28k),CR(calretinin)和PV(parvalbumin)是最常见的3种钙结合蛋白(calcium-binding proteins,CaBPs)。本研究首先观察了面口部给予伤害性刺激诱发大鼠延髓背角(又称三叉神经脊束核尾侧亚核)神经元表达FOS蛋白的状况;然后通过免疫荧光组织化学技术检测这些神经元内是否含有CaBPs(CB、CR和PV);最后通过免疫荧光和免疫电镜染色技术观察5-HT、GABA、甘氨酸转运体2(glycine transporter 2,GlyT2)、脑啡肽(enkephalin,ENK)或SP与CaBPs/FOS双标神经元间的联系。在光镜下可观察到:(1) FOS阳性神经元在延髓背角各层均有分布,以Ⅱ层最为密集;(2)大多数CB、CR或PV阳性神经元位于Ⅱ层,余者分布在Ⅰ层和Ⅲ层;(3) 5-HT、GABA、GlyT2,ENK及SP阳性纤维和终末主要位于延髓背角浅层(4)部分FOS阳性神经元同时呈CB、CR或PV阳性;(5) 5-HT、GABA、GlyT2或ENK阳性终末分别与FOS/CB、FOS/CR或FOS/PV双标神经元形成密切接触;(6) SP阳性终末与5-HT、GABA、GlyT2或ENK阳性终末同时与CB、CR或PV阳性神经元形成密切接触。在电镜下观察到5-HT、GABA、GlyT2或ENK阳性终末与CB、CR或PV阳性神经元主要形成对称型(抑制性)突触联系。这些结果提示在大鼠延髓背角,5-HT、GABA、甘氨酸或ENK可能通过抑制含钙结合蛋白的伤害性感受神经元来调节面口部伤害性信息的传递。     

Serotonin immunoreactivity in the circumesophageal nervous system of Hermissenda crassicornis

Immunohistochemical techniques were used to examine the distribution of serotonin-immunoreactive (5-HT-IR) neurons and processes in the circumesophageal nervous system of Hermissenda. Both the pedal and the cerebropleural ganglia contained immunoreactive neuronal somata, with the majority occurring in the pedal ganglia. Immunoreactive fibers and varicosities were identified in portions of the central neuropil, where we noted a consistent and specific relationship between 5-HT-IR axons, the optic nerve and the synaptic region in the neuropil near the photoreceptor terminals.     

大鼠翼腭神经节和脑动脉神经纤维一氧化氮合酶表达的年龄变化

目的：观察大鼠翼腭神经节及脑底动脉壁神经纤维一氧化氮合酶(NOS)表达的年龄变化规律。方法：用NADPH-d组织化学法及图像观察分析不同年龄组翼腭神经节及脑底动脉壁神经纤维NOS表达。结果：从幼年到成年，翼腭神经节中NOS神经细胞密度呈逐渐下降趋势，而胞体大小逐渐增加，至成年时最大，直至老年无明显改变。脑底动脉神经纤维密度从幼年到成年逐渐增高，从成年起维持较高密度直到老年。结论：出生后翼腭神经节和脑底动脉壁神经纤维NOS表达的年龄变化有其特定的规律。     

Ontogenesis of the snail, Helix aspersa: embryogenesis timetable and ontogenesis of GABA-like immunoreactive neurons in the central nervous system

Late stages of embryogenesis in the terrestrial snail Helix aspersa L. were studied and a developmental timetable was produced. The distribution of gamma-aminobutyric acid-like immunoreactive (GABA-ir) elements in the CNS of the snail was studied from embryos to adulthood in wholemounts. In adults, approximately 226 GABA-ir neurons were located in the buccal, cerebral and pedal ganglia. The population of GABA-ir cells included four pairs of buccal neurons, three neuronal clusters in the pedal ganglia, two clusters and six single neurons in the cerebral ganglia. GABA-ir fibers were observed in all ganglia and in some nerves. The first detected pair of GABA-ir cells in the embryos appeared in the buccal ganglia at about 63–64% of embryonic development. Five pairs of GABA-ir cell bodies were observed in the cerebral ganglia at about 64–65% of development. During the following 30% of development three more pairs of GABA-ir neurons were detected in the buccal ganglia and over fifteen cells were detected in each cerebral ganglion. At the stage of 70% of development, the first pair of GABA-ir neurons was found in the pedal ganglia. In the suboesophageal ganglion complex, GABA-ir fibers were first detected at about 90% of embryonic development. In the posthatching period, the quantity of GABA-ir neurons reached the adult status in four days in the cerebral ganglia, and in three weeks in the pedal ganglia. In juveniles, transient expression of GABA was found in the pedal ganglia (fourth cluster).     

GABAergic neurons express mu-opioid receptors in the ventrolateral orbital cortex of the rat

Behavioral studies have indicated that GABAergic modulation is involved in the opioid-induced antinociception in the ventrolateral orbital cortex (VLO). The aim of the current study was to examine whether the GABAergic neurons in the rat VLO expressed mu-opioid receptor subtype 1 (MOR1). This study employed immunofluorescence histochemical double-staining technique and showed that a considerable amount of GABA- and MOR1-like immunoreactive neurons existed in layers II-VI in the VLO. Of these GABA-like immunoreactive neurons, 92.0% of them showed MOR1-like immunoreactivities. Similarly, 80.2% of MOR1-like immuoreactive neurons also exhibited GABA-like immunoreactivities. These results provide morphological evidence that opioid-induced antinociception in the VLO might be due to an inhibitory effect by opioid via MOR1 on GABAergic neurons, resulting in disinhibition of VLO projection neurons and leading to activation of the VLO-PAG brainstem descending pain control system to depress the nociceptive inputs at the spinal cord level.     

猫肠系膜下神经节神经元与肠壁内传入神经元的突触联系

采用神经纤维和突触溃变的光镜和电镜结合方法，探讨肠系膜下神经节与来自肠神经丛内的传入神经元间的突触联系。切断肠系膜下神经节发出的分支，光镜下见节内存在溃变神经纤维；电镜下见有突触溃变，溃变轴突终末的大小多为１μｍ左右，主要含有球形透明囊泡，线粒体多少不等，与肠系膜下神经节神经元的树突或胞体形成轴－树型或轴－体型突触；溃变突触见有三种类型：电子致密型，电子透明型和神经丝型。确切证明了来自肠壁内的传入     

Immunohistochemical localization of GnRH-immunoreactive cell bodies and fibers in the nerve ganglion of Perinereis aibuhitensis (Annelida: Polychaeta)

The gonadotropin-releasing hormone (GnRH) gene sequence has been identified in an annelid polychaete marine worm using continual genome sequencing. The distribution of GnRH immunoreactive (ir) cell bodies and fibers in the nerve ganglion of the clam worm Perinereis aibuhitensis (Polychaeta) was examined by immunohistochemistry using a newly produced rabbit polyclonal antibody raised against the marine worm GnRH (mwGnRH). The specificity of the antibody was confirmed by dot blot assay. The antibody cross-reacted with mwGnRH, but not with other forms of GnRH such as octopus GnRH, tunicate GnRH-I, II, owl limpet GnRH, and lamprey GnRH-II. In P. aibuhitensis, mwGnRH-ir cell bodies were detected in the nuclei 15–22, the caudal part of the cerebral ganglion. Furthermore, mwGnRH-ir fibers were mainly observed in the optic neuropil, but mwGnRH-ir fibers were also detected in the central neuropil region, the subpharyngeal ganglion, and the ventral nerve cord. These results indicate that mwGnRH is synthesized in the cerebral ganglion, is transported through the subpharyngeal ganglion and the ventral nerve cord, and functions either as a neurotransmitter or neuromodulator.     

GABA-, serotonin-immunoreactive structures and Ca2+-binding protein in the neocortex of reeler mutant mice

To investigate the neurotransmitter organization of abnormally formed neocortex in the reeler mutant mice, an immunohistochemical study of GABA-, serotoninergic structures and Ca2+-binding protein was performed. GABA-ergic structures were identified according to the localization of glutamate decarboxylase (GAD), the key enzyme involved in GABA synthesis. The cells that were morphologically and immunohistochemically identical to Cajal-Retzius neurons, were found to have an unusual localization in the neocortex of reeler mutant mice, i.e. under the layer I, but not in its upper third, as seen in normal cerebral cortex. GAD-immunoreactive label was shown to accumulate in the neuropil of the middle and deep layers, while layer I contained only single granules. In contrast to what was observed in normal mice, serotonin-immunopositive fibers did not form superficial and deep plexuses in the neocortex, however they reached their targets. Thus, in abnormally formed neocortex, lacking the appropriate cytoarchitectonic organization, the structure of both intrinsic and projectional neurotransmitter systems was disturbed.     

Subcellular localization of serotonin-immunoreactivity in the pedal ganglion of Mytilus galloprovincialis (Mollusca, Bivalvia)

Serotonin has been localized in neurons of the pedal ganglion of Mytilus galloprovincialis by means of colloidal gold immunostaining. Ultrastructural quantitative analysis shows that gold particles are concentrated over perikarya and fibers containing a unique vesicle population. The vesicles are round or elliptical with a diameter ranging from 100 to 180 nm and have a dense core with areas of minor density. Their intense labelling suggests that they are the main cellular compartment where serotonin is stored.