突触及突触传递的研究概况

突触是神经元发出和接受神经冲动的基本结构 ,神经递质是通过突触的胞吐形式来传递所载信息 ,在胞吐过程中突触结合蛋白起着相当重要的作用。三磷酸鸟苷 (GTP)结合蛋白具有GTP酶的活性 ,可将GTP水解成GDP ,突触结合蛋白I(SytI)是一种膜整合蛋白 ,起着钙感受器的作用 ,Ca2 结合蛋白存在于突触囊泡膜上 ,调节融合孔的开放与关闭。神经递质及相应受体在突触传递过程中是不可缺少的因素 ,谷氨酸、γ 氨基丁酸 (GABA)、5 羟色胺 (5 HT)等及其受体是神经系统信息传递的主要物质基础 ,同时突触囊泡释放神经递质是一个由多种蛋白质介导的复杂过程     

牛磺酸对动物中枢神经系统的作用

牛磺酸(taurine)在大脑中含量丰富,对中枢神经系统具有重要作用,其可作为神经递质,参与细胞的生理活动;可作为神经营养因子,参与中枢神经系统的发育;也可作为渗透调节物质,调节钙的运输;同时牛磺酸还是神经保护剂,维持细胞膜结构的完整性,对谷氨酸产生的神经毒作用及内质网应激、线粒体紊乱具有保护作用。论文主要从神经递质、神经营养因子及神经保护作用等方面对牛磺酸在动物中枢神经系统的作用进行阐述,旨在为牛磺酸在动物神经发育及神经损伤修复中的应用提供参考。     

睾丸生理功能的植物性神经调节研究进展

研究发现除了内分泌调控外,睾丸神经对睾丸的发育、雄激素的分泌以及精子的发生也发挥重要的调节作用,与睾丸的内分泌调节功能相比较人们对植物性神经在睾丸生理活动调节方面的认识还很少。论文从睾丸的植物性神经分布、精索神经对睾丸发育和睾丸生理功能的影响以及睾丸不同发育时期胆碱能受体和肾上腺素能受体的分布、神经递质NE和Ach对睾丸发育和功能的影响等方面做了详细综述,并对今后的研究方向和研究意义做了展望。     

鸡肠道波形蛋白免疫组织化学研究

采用免疫组织化学SABC-AP法探究波形蛋白在黄羽肉鸡肠道的分布规律。结果:免疫组织化学显示,波形蛋白在鸡小肠黏膜上皮、小肠腺细胞腔面、黏膜下神经丛和肌间神经丛均呈强阳性表达;在黏膜的固有膜呈阳性表达,肌间神经丛的血管壁周围呈强阳性表达;波形蛋白在鸡大肠黏膜上皮、大肠腺呈阳性表达,在固有膜、黏膜下神经丛和肌间神经丛均呈强阳性表达。波形蛋白是神经胶质细胞的标记物之一,其在鸡肠道的分布特征表明肠神经胶质细胞(EGCs)不仅对肠神经系统(ENS)的肠神经节细胞起支持、营养和保护作用,而且可能参与肠黏膜屏障、肠腺分泌、肠道物质的分泌与吸收、肠蠕动及血液的供应调节等诸多功能。     

昆虫神经系统和神经干细胞的研究进展

昆虫的神经系统属于腹神经索型,控制着激素分泌、进食、运动以及支配内脏器官的活动,与脊椎动物的神经系统相比较,其结构简单易于实验操作。对昆虫神经系统的研究,可发现特异性靶标细胞,用于开发新型环保杀虫剂等。此外,昆虫神经干细胞的分裂、分化调控机制与脊椎动物甚至人类有很多的相似性,因而对昆虫神经干细胞的研究可为人类退化性神经疾病研究提供借鉴。本文着重阐述昆虫特别是果蝇的神经系统结构,神经细胞的类型,成神经细胞(neuroblasts,NBs)以及神经干细胞分裂、分化调控机制等方面的研究进展,期望能为开展家蚕神经干细胞的研究提供参考。     

肠道内分泌与营养素感应系统

动物肠道内消化代谢产生的各种营养素或其他化学物质,能够通过肠道内分泌和营养素感应系统发挥生理效应。作为肠道内分泌和营养素感应系统重要的组成部分,肠道内分泌细胞通过表面的感应受体(氨基酸感应受体、脂肪酸感应受体和葡萄糖感应受体等),识别感应肠道内各类营养素,不仅调节营养素吸收和代谢,同时能够分泌脑肠肽(胰高血糖素样肽-1、酪酪肽、胆囊收缩素等)。脑肠肽通过由中枢神经系统、自主神经系统以及肠神经系统构成的脑肠神经网络,参与调控机体摄食行为及其他生理功能。本文就动物肠道内分泌系统、脑肠轴以及营养素感应受体等方面研究进展进行综述。     

突触素研究进展

本文综述了突触素在神经组织及神经元和其它吸细胞中的分布。突触素参与钙离子依赖性神经递质的调节，对神经递质的快速释放和突触小泡的胞吐作用具有重要生理作用。突触素不仅可作为研究神经系统的发育，损伤及再生的标记物，而且可作为神经内分泌细胞的标记物。同时，为一些肿瘤及神经系统疾病诊断提供可靠依据。     

多巴胺及其受体的研究进展

多巴胺(dopamine，DA)是中枢神经系统中主要的神经递质，它参与运动、情感以及神经内分泌的调节，文中概述了多巴胺及其多巴胺受体的结构、功能以及作用机制的研究进展。     

源于肠道菌群的γ-氨基丁酸对机体的调节机制

γ-氨基丁酸(γ-aminobutyric acid,GABA)作为中枢神经系统主要的抑制性神经递质,一直被认为在大脑中合成。但是,近年来的研究发现肠道菌群也能够产生GABA,并通过神经通路、血液循环和免疫等方面调节机体,在焦虑抑郁、内脏疼痛、功能性肠病和代谢性疾病中发挥不可忽视的作用。现从GABA作用于机体的不同途径出发,主要阐述了源于肠道菌群的GABA对机体的调节机制,为GABA、肠道菌群的基础研究以及临床、生产应用提供参考和依据。     

色氨酸及其代谢产物在动物肠-脑轴中的作用研究进展

色氨酸是动物生长发育中所必需的氨基酸。色氨酸及其代谢物在肠道免疫、肠道蠕动、细胞分泌、调节神经反应、调控情绪、抗氧化等方面具有重要作用。肠-脑轴平衡是维持宿主体内平衡的关键,而色氨酸作为一些生物活性分子的前体,作用于宿主和微生物群之间,是肠-脑轴双向交流系统的基础。本文主要综述了色氨酸及其代谢产物与肠-脑轴联系的机制及未来研究中的展望,为氨基酸在动物生产中的应用及研究提供参考。     

An immunohistochemical study of the organization of ganglia and nerve fibres in the mucosa of the porcine intestine

In order to elucidate the organization of the enteric nervous system in the mucous plexus, wholemounts from six intestinal regions in six pigs were studied by vasoactive intestinal peptide, substance P, nitric oxide synthase and neurofilament proteins immunohistochemistry. The mucous plexus of both large and small intestine contained ganglia and isolated neurons. They were many and comparably larger in the caecum and colon, few in the ileum, and fewer and smaller in the jejunum. The mucous plexus was subdivided into the lamina muscularis mucosae and lamina proprial subplexuses, and based on location the latter was subdivided further in order to clarify their variations with respect to the amount, sizes and shapes of ganglia and neurons, sizes and orientation of nerve strands and immunoreactivities. Ganglia were situated at different topographical levels in the lamina muscularis mucosae subplexus, outer proprial and interglandular proprial meshworks in the lamina proprial subplexus with the majority of ganglia occurring in the outer proprial meshwork. The mucous plexus in the intestine of the pig is thus a ganglionated plexus showing marked segmental variation in the amount of intramucosal ganglia and isolated nerve cells. These new observations, calls for a re-examination of the mucous plexus to elucidate the regulatory mechanisms of importance in mucosal functions and consideration of the mucous plexus in the intestine of the pig to be one of the major ganglionated plexuses.     

Structural and functional components of the feline enteric nervous system

Neurohistological and immunohistochemical examinations of the feline enteric nervous system (ENS) were performed by using antibodies against neuron-specific enolase (NSE), phosphorylated neurofilaments (PN), non-phosphorylated neurofilaments (NPN) and vasoactive intestinal peptide (VIP), whereas glial cells were investigated by using antibodies against glial fibrillary acidic protein (GFAP). The study included full-thickness biopsies of the stomach, duodenum, jejunum, ileum and colon of 11 healthy cats. In this study, immunohistochemical staining of feline ENS with antibodies to NSE, PN and NPN revealed the presence of different ganglionated and aganglionated plexus. The two ganglionated plexus were arranged in a plexus submucosus internus & externus and a plexus myentericus. Furthermore, plexus mucosus and subserosal plexus represented two aganglionated plexus. GFAP-stained cellular elements were smaller than and in close contact to enteric neurons possibly resembling astrocytes of the central nervous system. VIP is one of the major neurotransmitters of enteric inhibitory neurons, and immunoreactivity was present in all layers of the gut, especially in ganglionated plexus. This is the first report, describing feline ENS by using immunohistochemical methods.     

Tissue Culture of the Enteric Nervous System from Equine Ileum

Ileal samples were harvested fresh from euthanized adult horses. The tissues were microdissected to prepare wholemount preparations for immunohistochemistry and for either explant or dissociated culture systems of the enteric nervous system. Explant culture systems were established using wholemounts of either the submucous plexus or the muscularis externa (including the myenteric plexus). Dissociated cell cultures could only be obtained from the submucous plexus. Culture systems were maintained for up to 5 days. Immunoreactivity for a neuronal marker (Pan-N) and for glial cell markers (GFAP and S100) indicated the presence of both neurons and enteric glia in the tissue culture preparations.This is the first report of equine enteric neurons being grown in tissue culture. Further refinements to the techniques will be required before this in vitro model can be used for quantitative analysis.     

Comparative study of the distribution of NOS-positive neurons in pigeon intestine

Nitric oxide (NO) plays an important role in regulating gut motility, mucosal barrier function and secretions in the enteric nervous system. Nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) staining has been used to identify nitrergic neurons of the enteric nervous system in different species. However, NADPH-d staining lacks specificity because it also reflects the presence of enzymes other than nitric oxide synthase (NOS). Therefore, NOS immunohistochemistry techniques are needed to test for nitrergic neurons in the avian gut. In the present work, the morphology, density and size of NOS-positive neurons in the duodenum, jejunum, ileum, caecum and rectum myenteric plexus of adult pigeons were investigated using NOS immunohistochemistry and whole-mount preparations techniques. The density of NOS-positive ganglion was highest in the ileum, similar to the caecum and rectum, and the lowest staining levels were observed in the duodenum. The staining intensity of NOS-positive neurons in the duodenum, jejunum and ileum was dark, followed by the rectal regions, with weak staining in the caecum. These results suggested that NOS immunohistochemistry and whole-mount preparation techniques provide an effective assessment method of the ganglia in the pigeon intestinal myenteric nerve plexus and are more accurate for cell counting compared with conventional sections.     

抗分泌性腹泻药物的研究进展

病理性腹泻是人和动物常见疾病症状之一,长期以来控制腹泻是医学上一个重点。基于肠病原菌及其产物诱导肠道分泌的机理,许多学者开展了相应的调控研究。肠细胞仍是直接研究和开发新药的主要焦点,随着新靶位ENS和促分泌素等发现,为人们在腹泻药物开发方面提供了更广阔的空间     

胶质纤维酸性蛋白在黄羽肉鸡肠道中的分布研究

本研究旨在探究胶质纤维酸性蛋白（glial fibrillary acidic protein,GFAP）在黄羽肉鸡肠道中的分布规律。使用免疫组织化学SABC-AP法,观察鸡肠道中GFAP的分布规律。结果显示,GFAP在鸡小肠黏膜上皮、小肠腺细胞腔面、小肠黏膜下神经丛和肌间神经丛及其血管壁周围均呈强阳性表达,在黏膜固有膜上呈阳性表达;GFAP在鸡大肠黏膜上皮、大肠腺中呈阳性表达,在大肠黏膜下神经丛和肌间神经丛均呈强阳性表达。GFAP是肠神经胶质细胞的特异性标记物之一,观察其在鸡肠道的分布特征有助于阐明肠神经胶质细胞在肠道各段的分布规律,为研究鸡肠神经胶质细胞的功能提供形态学依据。     

Study on the Distribution of Glial Fibrillary Acidic Protein in Intestine of Yellow Feather Broiler

The experiment was conducted to explore the distribution of glial fibrillary acidic protein (GFAP) in Yellow feather broiler,and to investigate the morphological characteristics of glial cells of chicken. The distribution of GFAP was studied by immunohistochemistry SABC-AP method. The results showed that GFAP were expressed strong positively in chicken small intestinal mucosa epithelium, intestinal gland cell cavity surface, submucosal plexus and myenteric plexus; The expressions of GFAP were positive in the mucosal lamina propria and myenteric nerve plexus around the blood vessel; In avian escherichia sticky epithelial membrane, colorectal adenocarcinoma,GFAP were expressed positively, and the expressions were strong positive in mucosa epithelium, submucosal plexus and myenteric plexus. GFAP was one of the specific marker of enteric glial cells, and the observation of distribution of GFAP in chicken intestinal tract was help for elucidating the enteric glial cells in the distribution of the intestine and providing the morphological basis for the study of chicken glial cell function.     

Infection of the enteric nervous system by Borna disease virus (BDV) upregulates expression of Calbindin D-28k

Borna disease virus (BDV) is a neurotropic agent infecting distinct neuronal subpopulations in the central nervous system of various mammalian species possibly including humans. Horses, a major natural host for BDV, show gastrointestinal dysfunctions besides characteristic neurological symptoms. Therefore, we hypothesized that enteric neurons may be targets of BDV replication. The presence of BDV-specific antigen in subpopulations of the ENS was investigated. Four-week-old Lewis rats were infected intracerebrally and sacrificed 4-14 weeks post infection (p.i.). BDV-immunoreactive neurons were found in submucous and myenteric neurons of the proximal colon. Fourteen weeks p.i., the proportion of BDV-positive neurons was 44+/-17 and 24+/-7% in the submucous and myenteric plexus, respectively. The majority of BDV-positive myenteric neurons showed immunoreactivity for choline acetyltransferase. Expression of Calbindin D-28k (CALB) was found in 96% of submucous and 67% of myenteric BDV-immunoreactive neurons. Additionally, the number of CALB-immunoreactive neurons was significantly higher in the myenteric plexus of infected rats compared to controls. These data indicate that BDV infects specific subpopulations of enteric neurons. Therefore, the ENS might serve as a site for BDV replication and as an immunoprivileged reservoir for BDV. In addition, upregulation of CALB in neurons of the myenteric plexus is probably induced during BDV-infection.     

γ-氨基丁酸及其在畜禽生产中的研究进展

γ-氨基丁酸(γ-aminobutyric acid, GABA)是一种在动物体内起神经镇定作用的非蛋白质氨基酸,广泛存在于哺乳动物中枢神经系统、外周神经系统和一些内分泌细胞中,是一种重要的神经抑制性递质,对提高畜禽采食量、泌乳量、成活率、抗应激、降低呼吸频率、缩短发情间隔等方面有着显著的效果。作者对GABA的制备、生理功能及在畜禽生产中的研究现状作了简要综述。