人胎胃壁内NOS阳性神经元发育的研究

研究用NADPH-d组织化学法对第3个月胎龄至足月人胎胃壁内NOS阳性神经元的分化,迁移和生长发育进行了观察。结果表明：第5个月龄时,肌层神经节处的圆形细胞出现一氧化氮合酶（nitric oxide synthase,NOS)阳性反应。第6个月龄时,NOS阳性细胞分化演变成NOS阳性神经细胞,细胞呈圆形或椭圆形,核大,细胞质极少,由细胞发出短小的6个月龄时,NOS阳性细胞分化演变成NOS阳性神经细胞,细胞呈圆形或椭圆形,核大,细胞质极少,由细胞发出短小的突起,有部分NOS阳性细胞分化演变成梭形的NOS阳性神经细胞,呈条索状排列和粘膜下层延伸,吸的到达粘膜层,在粘膜层形成网状细胞,第7个月龄时,神经元细胞明显增大,细胞质增多,染色加深,在肌层形成神经节,神经节细胞突起投射到整个肌层,第8-10个月龄时,肌层和粘膜下层神经元日趋成熟,细胞质增多,染色强度加深,肌层神经纤维分布密度增加,大多数神经纤维增粗,有的呈弹簧样弯曲,其走向与肌纤维长轴平行。结果提示;人胎胃壁内NOS阳性神经元来源于胚胎早期肌层神经节处的圆形细胞,通过分化,生长发育形成成熟的NOS阳性神经元。     

人十二指肠血管活性肠肽能P物质能神经分布的研究

本文采用免疫组织化学ＡＢＣ法研究血管活性肠肽（ＶＩＰ） 能神经和Ｐ物质（ＳＰ） 能神经在人十二指肠壁内的分布。结果显示： ＶＩＰ能和ＳＰ能神经纤维和神经元均呈棕褐色; ＶＩＰ能神经纤维遍布肠壁各层,ＳＰ能神经纤维主要分布于肌层和神经丛; ＶＩＰ能和ＳＰ能神经元见于肌间和粘膜下神经, 尤以后者为多, 但形态特点不同; 在肌间神经丛, ＳＰ能神经元比ＶＩＰ能神经元多。粘膜内可见ＶＩＰ能和ＳＰ能神经元, 多单个分布在粘膜肌层内。结果表明： １ＶＩＰ能和ＳＰ能神经在人十二指肠壁内分布有差异。２粘膜内存在ＶＩＰ能和ＳＰ能神经元     

大鼠食管胸段，腹段乙酰胆碱酯酶阳性神经的配布

大鼠食管胸段和腹段壁内乙酰胆碱酯酶（ＡＣｈＥ）阳性神经存在于神经束和分支的粗细神经纤维内,也见于外膜丛,肌间丛,粘膜下丛和粘膜肌内。食管肌层内ＡＣｈＥ阳性神经纤维多而密集,而食管腹段肌内尤为丰富,肌间神经纤维末梢分布于肌束表面,可能与控制肌纤维活动有关;分布于肌内,粘膜下层和上皮基部的ＡＣｈＥ阳性神经中,尚含有内脏感觉神经纤维。食管壁的肌间丛和粘膜下丛内散在有多极形和卵园形的ＡＣｈＥ阳性神经元,在食管腹段内数多,而以中小型神经元为主。     

广东乌龟消化道组织学观察

采用常规石蜡切片法,观察了广东乌龟的食道、胃、小肠和大肠的组织结构.结果发现,这四种器官都是由粘膜层、粘膜下层、肌层和外膜组成,各部分的差别主要在于粘膜层和肌层.食道和大肠上皮为复层柱状上皮:胃和小肠上皮为单层柱状上皮.食道粘膜上皮特化形成与呼吸有关的绒毛.胃有大量胃腺,腔面有纵行皱襞.小肠表面有大量绒毛,在绒毛中可见肠腺.大肠具粘膜皱襞和较多的杯状细胞,无绒毛,可见许多分散的淋巴小结.胃和肠道肌肉为内环外纵,内环肌较厚,外纵肌较薄.     

嫁（虫戚）神经系统结构的初步研究

嫁虫戚神经系统包括一对脑神经节、一对足神经节、一对侧神经节和一个脏神经节.左右脑神经节间有较长的神经联合,脑-足、脑-侧神经节间有较长的连索存在.各神经节均由三部分组成:神经节鞘膜、胞体区和神经纤维网.脑神经节相同类型神经元胞体聚集分布,其余神经节神经元未见有明显分区和分层现象.神经元胞体直径一般不超过20μm,这些特征与已研究的前鳃亚纲种类显著不同,可能与该种螺类处于系统演化中较低等地位有关.     

人小肠粘膜内神经元的组织化学与免疫组织化学观察

使用ＮＡＤＨ黄递酶组化法,我们观察到小肠的固有层和粘膜肌层内的神经元和小神经节。粘膜内神经元经ＮＡＤＨ黄递酶组化与ＮＳＥ免疫组化法联合染色,由蓝色转变为黑色;在同一切片内粘膜下丛和肌间神经丛的神经元具有相同的染色性。粘膜内一些ＡＣｈＥ阳性反应神经元,胞体呈校形,两端伸出较长的突起;另一些神经元胞体呈卵圆形或不规则形,可见突起伸入肠膝下部,参与腺周丛。粘膜内神经元的类型和性质有待进一步研究。     

人胎视皮质皮质下层NPY－IR神经元的发育

本文用免疫组化方法研究了１６周至足月人胎视皮质皮质下层ＮＰＹ－ＩＲ神经元的发育。各胎龄视皮质ＳＰ层内均有ＮＰＹ－ＩＲ神经元分布。从１６周至２６周,ＮＰＹ－ＩＲ神经元密度逐渐增高并于２６周达高峰;３２周以后阳性神经元密度随胎龄增长而下降。人胎视皮质ＳＰ层ＮＰＹ－ＩＲ神经元形态也随胎龄而变化;２０周以前,ＮＰＹ－ＩＲ神经元大多是胞体较小,突起短而少的未分化神经元、ＳＰ层内ＮＰＹ－ＩＲ纤维少。２０周以后,ＮＰＹ－ＩＲ神经元胞体增大,突起增多、变长;多极和双极、双簇神经元随胎龄增长而增多;ＳＰ层内的ＮＰＹ－ＩＲ纤维大量增加,部分纤维穿入皮质板。３２周以后,多极ＮＰＹ－ＩＲ神经元逐渐减少,双极双簇神经元所占比例相对增高。ＮＰＹ免疫组化结合ＮＡＤＰＨ－ｄ组化显示人胎视皮质ＳＰ层大多数ＮＰＹ－ＩＲ神经元同时呈ＮＯＳ阳性。本研究观察到人胎视皮质ＳＰ层内ＮＰＹ－ＩＲ神经元发育可分为发生、成熟和退化三个阶段。     

神经激肽B受体在小鼠消化道内的定位

采用免疫组织化学ABC染色方法研究了神经激肽B受体（NK3r)在小鼠消化道的分布。MK3r样阳性的神经无胞体及神经纤维主要分布在十二指肠,空肠,回肠及结肠的粘膜下层神经丛和肌间神经丛,NK3r样阳性产物在食管,胃和直肠的神经丛中未见分布;NK3r样阳性产物大部分避限于神经细胞表面,也存在于胞和一些轴突内部,并在胞质中较细胞表面染色浅。。统计结果表明NK3r样免疫阳性神经元占肠神经系统神经元总数的0．5－1％,提示小鼠消化道内NK3r样阳性神经元可能参与消化功能的调节。     

人小肠粘膜内神经元的组织学与组织化学观察

一般认为,胃肠道粘膜内不存在神经元,粘膜神经丛仅由神经纤维组成。本文使用常规组织学方法和 NADH 黄递酶组化法证明在人小肠粘膜内可见到单个的神经元或由2～5个神经元组成的神经节。神经元胞体大小不等,形态多样,除梭形、卵圆形和不规则形外,还有呈扁平形的。粘膜内神经元多数位于固有层内,常紧贴粘膜肌;粘膜肌层内也可见到神经元。我们认为,小肠粘膜内神经元是肠神经系中粘膜神经丛的一部分。     

人体中有哪些神经节

在周围神经系统中,神经元胞体聚集在一起,由一层结缔组织膜包被形成的小结节称作神经节,可分为感觉性神经节和植物性神经节两类。感觉性神经节是感觉神经元胞体所在,内为大小不等的假单极神经元胞体相聚,胞体多呈圆或卵圆形,其周围分布有许多小型的神经节胶质细胞,也称卫星细胞。感觉神经节按其所在位置分为脊神经节和脑神经节。脊神经节位于近椎间孔处,连在脊神经背根上,常称背根节,共31对。大约有一半的人第一颈神经背根及     

人胎大肠氮能神经元发育的研究

By using histochemical methed of NADPH-diaphorse, the development of the nitrergic neurons in the large intestine of human fetus were studied. The results showed: At the fifth month of gestation, weak positive reaction of nitric oxide synthase (NOS) appeared in part of the round cells of intermuscular ganglia. The round cells differentiated into the nitrergic nerve cells. At the sixth month, the bodies of nitrergic neurons were obviously enlarged, the processes of which were lengthened. The nitrergic nerve fibers were seen in the muscle layer, the submucosa and the base of the intestinal gland. The growth and development of nitrergic neurons reached its peak at the seventh month. The number of intermuscular ganglionic cells was increased. The density of nitrergic nerve fibers was increased in the inner circular muscle layer, and have bead-like structures. At the eighth to tenth month, the staining intensity of nitrergic neurons was increased. The myenteric plexus was densely distributed with nitrergic nerve cell bodies, whereas the submucosa and the inner circular muscle layers contained only a few neurons. The nitrergic nerve fibers were observed in all layer of large intestine, the density of the distribution of nitrergic nerve fibers was by far the highest in the inner circular muscle layer, less in the submucosa and outer longitudinal muscle layer, and only a few were found in the mucous layer. To our knowledge, it is the first time that the development of nitrergic neurons in the large intestine of human fetus was demonstrated.     

An immunohistochemical study of the innervation of the large intestine of the toad (Bufo marinus)

The distribution of intrinsic enteric neurons and extrinsic autonomic and sensory neurons in the large intestine of the toad, Bufo marinus, was examined using immunohistochemistry and glyoxylic acid-induced fluoresecence. Three populations of extrinsic nerves were found: unipolar neurons with morphology and location typical of parasympathetic postganglionic neurons containing immunoreactivity to galanin, somatostatin and 5-hydroxytryptamine were present in longitudinally running nerve trunks in the posterior large intestine and projected to the muscle layers and myenteric plexus throughout the large intestine. Sympathetic adrenergic fibres supplied a dense innervation to the circular muscle layer, myenteric plexus and blood vessels. Axons containing colocalized calcitonin gene-related peptide immunoractivity and substance P immunoreactivity distributed to all layers of the large intestine and are thought to be axons of primary afferent neurons. Five populations of enteric neurons were found. These contained immunoreactivity to vasoactive intestinal peptide, which distributed to all layers of the large intestine; galanin/vasoactive intestinal peptide, which projected to the submucosa and mucosa; calcitonin gene-related peptide/vasoactive intestinal peptide, which supplied the circular muscle, submucosa and mucosa; galanin, which projected to the submucosa and mucosa; and enkephalin, which supplied the circular muscle layer.     

Nitric oxide synthase immunoreactivity in the enteric nervous system of the developing human digestive tract

We have investigated indirectly the presence of nitric oxide in the enteric nervous system of the digestive tract of human fetuses and newborns by nitric oxide synthase (NOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry. In the stomach, NOS immunoactivity was confined to the myenteric plexus and nerve fibres in the outer smooth musculature; few immunoreactive nerve cell bodies were found in ganglia of the outer submucous plexus. In the pyloric region, a few nitrergic perikarya were seen in the inner submucous plexus and some immunoreactive fibres were found in the muscularis mucosae. In the small intestine, nitrergic neurons clustered just underneath or above the topographical plane formed by the primary nerve strands of the myenteric plexus up to the 26th week of gestation, after which stage, they occurred throughout the ganglia. Many of their processes contributed to the dense fine-meshed tertiary nerve network of the myenteric plexus and the circular smooth muscle layer. NOS-immunoreactive fibres directed to the circular smooth muscle layer originated from a few NOS-containing perikarya located in the outer submucous plexus. In the colon, caecum and rectum, labelled nerve cells and fibres were numerous in the myenteric plexus; they were also found in the outer submucous plexus. The circular muscle layer had a much denser NOS-immunoreactive innervation than the longitudinally oriented taenia. The marked morphological differences observed between nitrergic neurons within the developing human gastrointestinal tract, together with the typical innervation pattern in the ganglionic and aganglionic nerve networks, support the existenc of distinct subpopulations of NOS-containing enterice neurons acting as interneurons or (inhibitory) motor neurons.     

Scanning electron microscopy of the muscle coat of the guinea-pig small intestine

Summary We have studied the layers of the muscular coat of the guinea-pig small intestine after enzymatic and chemical removal of extracellular connective tissue. The cells of the longitudinal muscle layer are wider, have rougher surfaces, more finger-like processes and more complex terminations, but fewer intercellular junctions than cells in the circular muscle layer. A special layer of wide, flat cells with a dense innervation exists at the inner margin of the circular muscle layer, facing the submucosa. The ganglia of the myenteric and submucosal plexuses are covered by a smooth basal lamina, a delicate feltwork of collagen fibrils, and innumerable connective tissue cells. The neuronal and glial cell processes at the surface of ganglia form an interlocking mosaic, which is loosely packed in newborn and young animals, but becomes tightly packed in adults. The arrangement of glial cells becomes progressively looser along finer nerve bundles. Single varicose nerve fibres are rarely exposed, but multiaxonal bundles are common. Fibroblast-like cells of characteristic shape and orientation are found in the serosa; around nerve ganglia; in the intermuscular connective tissue layer and in the circular muscle, where they bridge nerve bundles and muscle cells; at the submucosal face of the special, flattened inner circular muscle layer; and in the submucosa. Some of these fibroblast like cells correspond to interstitial cells of Cajal. Other structures readily visualized by scanning electron microscopy are blood and lymphatic vessels and their periendothelial cells. The relationship of cellular elements to connective tissue was studied with three different preparative procedures: (1) freeze-cracked specimens of intact, undigested intestine; (2) stretch preparations of longitudinal muscle with adhering myenteric plexus; (3) sheets of submucosal collagen bundles from which all cellular elements had been removed by prolonged detergent extraction.     

Distribution of NADPH Diaphorase-Positive Neurons in the Enteric Nervous System of the Rabbit Intestine

Nitric oxide (NO) has been proposed as an inhibitory transmitter in gastrointestinal muscle relaxation. We analyzed the distribution of nitric-oxide producing neurons in the rabbit intestine through nicotinamide-adenine-dinucleotide-phosphate-diaphorase histochemistry. By this reliable and convenient method, we visualized neuronal nitric-oxide-synthase, the enzyme responsible for nitric oxide generation, in the rabbit intestine. In the ileum and rectum, nitric-oxide-synthase-related diaphorase activity was present in the myenteric plexus ganglion cells, and in the nerve fibers in the internodal strand, secondary, and tertiary plexuses. These fibers were particularly abundant in the deep circular rather than in the outer longitudinal muscle layer. In the inner submucosal plexus, we found scarce labeled neurons. Labeled neural somata showed a range of sizes and shapes suggesting different functional roles. The present basic information is required to use the rabbit as an experimental animal in neurochemical NO enteric research.     

Immunohistochemical study of 5-HT-containing neurons in the teleost intestine: relationship to the presence of enterochromaffin cells

Summary The formaldehyde-induced fluorescence technique had shown 5-hydroxytryptamine-containing enteric neurons in the intestine of the teleost Platycephalus bassensis, but did not reveal such neurons in the intestine of Tetractenos glaber or Anguilla australis. Re-examination of these animals with 5-hydroxytryptamine immunohistochemistry showed immunoreactive enteric neurons in the intestine of all three teleost species. The 5-hydroxytryptamine-containing enteric neurons showed essentially the same morphology in all species examined: the somata were situated in the myenteric plexus, extending down into the circular muscle layer, but none were found in the submucosa; processes were found in the myenteric plexus, the circular muscle layer and the lamina propria. It was concluded that the neurons may innervate the muscle layers or the mucosal epithelium, but were unlikely to be interneurons. In a range of teleosts, enterochromaffin cells were found in the intestine of only those species in which the formaldehyde technique did not visualize neuronal 5-hydroxytryptamine. Available evidence suggests that, in vertebrates, 5-HT-containing enterochromaffin cells are lacking only where there is an innervation of the gut mucosa by nerve fibres containing high concentrations of 5-HT.     

Expression of neuropeptides and anoctamin 1 in the embryonic and adult zebrafish intestine, revealing neuronal subpopulations and ICC-like cells

This immunohistochemical study in zebrafish aims to extend the neurochemical characterization of enteric neuronal subpopulations and to validate a marker for identification of interstitial cells of Cajal (ICC). The expression of neuropeptides and anoctamin 1 (Ano1), a selective ICC marker in mammals, was analyzed in both embryonic and adult intestine. Neuropeptides were present from 3 days postfertilization (dpf). At 3 dpf, galanin-positive nerve fibers were found in the proximal intestine, while calcitonin gene-related peptide (CGRP)- and substance P-expressing fibers appeared in the distal intestine. At 5 dpf, immunoreactive fibers were present along the entire intestinal length, indicating a well-developed peptidergic innervation at the onset of feeding. In the adult intestine, vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating peptide (PACAP), galanin, CGRP and substance P were detected in nerve fibers. Colchicine pretreatment enhanced only VIP and PACAP immunoreactivity. VIP and PACAP were coexpressed in enteric neurons. Colocalization stainings revealed three neuronal subpopulations expressing VIP and PACAP: a nitrergic noncholinergic subpopulation, a serotonergic subpopulation and a subpopulation expressing no other markers. Ano1-immunostaining revealed a 3-dimensional network in the adult intestine containing multipolar cells at the myenteric plexus and bipolar cells interspersed between circular smooth muscle cells. Ano1 immunoreactivity first appeared at 3 dpf, indicative of the onset of proliferation of ICC-like cells. It is shown that the Ano1 antiserum is a selective marker of ICC-like cells in the zebrafish intestine. Finally, it is hypothesized that ICC-like cells mediate the spontaneous regular activity of the embryonic intestine.     

Different distribution of S-100 protein and glial fibrillary acidic protein (GFAP) immunoreactive cells and their relations with nitrergic neurons in the human fetal small intestine.

The appearance, distribution and some histochemical features of non-neuronal cells (NN cells) associated with the myenteric plexus of human fetal small intestine have been studied by means of S-100 protein and GFAP immunocytochemistry between the 10th and 17th week of gestation. In addition, double labelling immunocytochemistry using an antibody raised against a constitutive isoform of nitric oxide synthase (bNOS) in combination with an S-100 protein antibody was applied to investigate the morphological relations between NN cells and nitrergic neurons in the developing gut wall. Cells with immunoreactivity for both glial-specific proteins are already present in the 10th week of gestation. While cells with S-100 protein immunoreactivity are located within the circular muscle layer as well as in the myenteric, and submucous plexuses, cells with GFAP immunopositivity are mainly restricted to the side of the myenteric plexus adjacent to the longitudinal muscle layer. In contrast to the dense network formed by S-100 protein immunopositive structures the GFAP immunopositive cells appear singly and do not connect into a network. Double-labelling immunocytochemistry reveals nitrergic fibers (NOS-IR) in close relation to the S-100 protein immunoreactive glial network. NOS-IR varicosities are in close association with the surface of those cells both in the circular muscle layer (CM) and in the tertiary plexus. It is concluded that two populations of NN cells with different locations and different immunohistochemical characters appear and develop together with the enteric ganglia in the human fetal intestine. The close morphological relation of NOS-IR fibers with S-100 protein immunopositive cellular network indicate a functional relationship between S-100 protein immunopositive cells and the nitrergic nerves during the early development of human enteric nervous system (ENS).