疼痛对垂体细胞作用的电镜观察

垂体细胞(Pituicytes)是神经垂体内一种特殊分化的神经胶质。多分布在神经叶、漏斗柄及正中隆起。它与丘脑下部-垂体束的神经分泌纤维有密切关系。常见垂体细胞的突起包绕小型神经分泌纤维。有时其胞浆内显示吞噬退化的神经末梢。近来发现,垂体细胞可与神经分泌纤维形成突触。Kiernan认为,垂体细胞可释放激动剂,能促进神经分泌纤维的新生及神经分泌粒的成熟。Hansh报道,垂体细胞可合成和分泌γ-氨基丁酸(GABA)。GABA可与神经分泌纤维膜上的受体结合而发挥作用。GABA为一种抑制性神经递质,可     

大鼠下丘脑室旁核神经元的超微结构特征

在透射电镜下,我们观察到PVN大细胞具有四种不同的形态,认为属于同一类细胞分泌活性的不同时相:(1)合成相,粗面内质网非常丰富,(2)加工相:Golgi复合体发达,周围分布着一些神经分泌颗粒;(3)储存相:神经分泌颗粒明显增多:(4)转运相:细胞质内神经分泌颗粒很少,而在细胞周围可见一些充满神经分泌颗粒的突起。免疫电镜的结果也证实了VP阳性神经细胞具有类似的四种不同形态,其中在合成相,粗面内质网囊膜呈免疫阳性反应,还有一些PAP免疫复合物沉积在细胞质中。而在加工,储存和转运相,神经分泌颗粒呈免疫阳性反应。同样,小细胞亦具有三种不同形态特证,可能代表着不同的功能状态。     

神经营养因子3-壳聚糖载体诱导神经干细胞分化为神经元的亚型及其电生理特性

背景：前期研究已证实神经营养因子3-壳聚糖载体可支持神经干细胞的存活和增殖,同时可高效诱导神经干细胞向神经元方向分化。目的：观察神经营养因子3-壳聚糖载体对神经元发育进程、发育各阶段电生理特性及发育成熟神经元亚型的影响。方法：取第3代新生大鼠脊髓神经干细胞,分4组培养：空白对照组加入神经干细胞培养基,壳聚糖组加入含壳聚糖的神经干细胞培养基,NT3组加入含神经营养因子3的神经干细胞培养基,NT3-壳聚糖组加入含神经营养因子3-壳聚糖载体的神经干细胞培养基。利用免疫荧光染色观察神经干细胞发育各阶段标志物表达情况,借助全细胞膜片钳技术评价神经干细胞发育过程中电生理特性的变化情况,利用免疫荧光染色观察神经干细胞分化21 d后中间神经元的亚型。结果与结论：(1)Nestin、DCX、Tuj1及MAP2免疫荧光染色显示,神经营养因子3-壳聚糖载体维持了神经干细胞池的稳态,并且通过加速神经母细胞的发育进程来促进神经元发育成熟;(2)全细胞膜片钳记录发育过程中的细胞发现,营养因子神经营养因子3和神经营养因子3-壳聚糖在发育早期对神经干细胞膜功能以及细胞膜上离子通道的发育成熟具有一定的促进作用,但是仅有...     

一种新颖的神经胶质细胞-嗅鞘细胞

嗅鞘细胞(OECs)移植治疗脊髓损伤(SC I)已显示出良好的应用前景,不同来源的OECs体外培养时,在不同发育阶段和不同生长环境中具有不同的生物学特性。OECs具有特异性的标志蛋白,如S-100、p75NTR、GFAP等。体外培养的OECs分泌NGF、BDNF、NT-3/4、GDNF等多种促进神经细胞生长、分化和神经纤维再生的神经营养因子。将OECs植入脊髓损伤部位,该细胞能分裂增殖,并可抑制胶质瘢痕的形成,拮抗Nogo等神经再生抑制性因子的活性,包绕再生轴突形成髓鞘。由于OECs具有上述独特的生物学功能,被认为是继神经干细胞和雪旺氏细胞之后可用于移植治疗脊髓损伤的一种新颖的神经胶质细胞。     

新型组织工程化改性胶原-壳聚糖复合支架制备与神经细胞的相容性北大核心

背景:周围神经缺损的治疗在再生医学领域仍然具有挑战性,支架材料的应用被认为是有前途的探索方向之一,理想的支架材料应是安全、耐用和缺乏抗原性的。目的:探讨制备一种新型的组织工程化改性胶原-壳聚糖支架,并探索其在大鼠横断坐骨神经模型中用作桥梁修复神经损伤的可能。方法:先制备出胶原-壳聚糖复合支架,然后用1-乙基-3-(3-二甲基氨基丙基)-碳化二亚胺,N-羟基琥珀酰亚胺对支架进行化学改性即交联。接着将神经干细胞种植于支架上,之后连同支架-种子细胞在体内植入坐骨神经缺损部位。结果与结论:制得的变性交联胶原-壳聚糖复合支架具有三维立体网状结构。将支架-种子细胞移植4周后,可在损伤的坐骨神经中发现S-100神经丝蛋白200表达。结果表明这种组织工程化改性交联胶原-壳聚糖复合支架具有良好的细胞相容性。     

神经分泌之进展

一、神经分泌细胞之概念,发展史及种系演化。脊椎及无脊椎动物的中枢神经系统中某些神经细胞群,既具神经元之特性(传导神经冲动),又具有类似腺细胞分泌功能,其分泌物进入血循环,以激素方式影响远处效应细胞,这类神经元称为神经分泌细胞。其分泌物称为神经分泌或神经内分泌,因其分     

神经白细胞素

神经白细胞素(NLK)是一种对神经细胞和免疫细胞均有调节作用的蛋白质。在骨骼肌、脑及骨髓等组织中均可检测到较高的NLK活性。神经受损的肌肉组织和丝裂原刺激的T细胞均可产生NLK。NLK对脊髓神经元和感觉神经元有营养作用,可促进这些神经元的存活能力。NLK亦可促进成熟的B淋巴细胞分化成为抗体分泌细胞,但B细胞一旦分化成为抗体分泌细胞,其分泌抗体的能力则不再依赖于NLK的存在。NLK与6-磷酸葡萄糖异构酶(GPI)的氨基酸顺序高度同源,并具有GPI的酶活性,但酶活性与其对神经细胞和免疫细胞的作用无关。此外,NLK与HIV-1病毒包膜糖蛋白gp120的顺序部分同源,gp120能抑制NLK的生物活性,提示艾滋病的免疫缺陷和中枢神经系统症状可能与gp120干扰NLK的功能有关。     

神经白细胞素—分裂原刺激T细胞产生的淋巴因子

神经白细胞素(Neuroleukin)是一种新的神经生长因子,也是受分裂原刺激后T细胞分泌的一种淋巴因子。作者发现,神经白细胞素可诱导培养中的人单个核血细胞分泌免疫球蛋白。神经白细胞素作用于抗体分泌细胞的早期成熟阶段,它没有分裂原的直接作用,但反应后期可发生细胞增殖。通过某些活性的测定,作者认为神经白细胞素没有     

壳聚糖纳米纤维支架对猪肝细胞分泌猪内源性逆转录病毒的影响

探讨壳聚糖纳米纤维支架对肝细胞的PERV分泌量以及其感染性的影响。将新鲜分离的猪肝细胞接种于壳聚糖纳米纤维支架或普通条件下连续培养7 d,分为实验组(Nano组)和对照组(Hep组)。每天收集培养液检测逆转录酶(RT)活性,并通过RT-PCR和实时定量PCR测定PERV RNA水平。通过western blot检测细胞裂解液中PERV gag 30蛋白含量。细胞培养液体外孵育HEK293细胞以测定其感染性。结果表明:实时定量PCR、RT活性以及western blot具有相似的变化趋势。在体外培养10 h和2 d出现PERV分泌高峰然后逐渐下降。除第6 dPERV RNA水平和第5 d蛋白水平实验组明显高于对照组外,其余均无明显差异。体外感染实验无HEK293细胞感染。壳聚糖纳米纤维支架会延长猪肝细胞的PERV分泌时间但对分泌量以及体外感染性并无明显影响,可安全用于生物人工肝。     

生物反应器内工程化软骨的三维动态构建

组织工程化软骨的体外构建,可克服传统治疗方法的一些不足,被认为是一种有望治疗关节软骨缺损的有效途径。文章旨在探究人源脂肪干细胞结合壳聚糖/明胶水凝胶支架,在体外动态环境下构建工程化软骨的优势。实验制备了壳聚糖/明胶水凝胶支架,对其理化性能进行了检测,后将人源脂肪干细胞作为种子细胞,接种在支架上进行软骨的诱导培养,其中,选用转瓶作为动态的培养环境。分别通过组织学染色、共聚焦显微镜观察、扫描电镜观察等考察了软骨的构建情况,结果显示壳聚糖/明胶支架的平均孔径为(118.25±19.51)μm,孔隙率为(82.60±2.34)%,溶胀率为(361.28±0.47)%,弹性模量为(61.2±0.16)k Pa,具有良好生物相容性。动态载支架-转瓶内水凝胶支架中细胞蛋白多糖的表达更显著,细胞生长分布更加均匀,分泌细胞外基质基本填满整个支架,可促进人源脂肪干细胞的软骨分化和体外软骨的构建。     

Unmyelinated nerve fibers of the human mandibular nerve

The aim of this research is to find and to evaluate morphometorically the unmyelinated nerve fibers in the human mandibular nerve using a light microscope. Our report demonstrates for the first time the presence of the unmyelinated nerve fibers of the human mandibular nerve stained by a special method. Our results also indicate that there is a morphometric change with aging in the unmyelinated axons of the nerve.     

A thirteenth cranial nerve: the cloacal nerve

The completion by vertebrates of micturition, defecation, and copulation via the cloaca or its derivatives is hypothesized to be best explained by the existence of a thirteenth cranial nerve, the cloacal nerve, which, similar to the facial and trigeminal nerves, functions as a mixed cranial nerve containing both general and special components.     

Variation of the spinal nerve compositions of thoracodorsal nerve

Thoracodorsal nerve distributes to the latissimus dorsi muscle. The aim of this study was to investigate the anatomic variation of the spinal nerve compositions of thoracodorsal nerve and to confirm which spinal nerve is a main component in participating amount. The most frequent type was consisted of C7 and C8 in 60%. Next frequent type was C6, C7, and C8 in 25%. Third type was C6 and C7 in 10% and fourth type was C7 alone in 5%. The diameter of each spinal nerve comprising thoracodorsal nerve was 1.20 +/- 0.23 (mean +/- SD) mm at C7, 0.43 +/- 0.15 mm at C8, and 0.33 +/- 0.09 mm at C6. These results show that the C7 nerve was the main component of thoracodorsal nerve and the anatomic variation appeared at the spinal nerve that participate by small amounts, as be excepted (C6 and C8).     

Unmyelinated nerve fiber analysis of the human oculomotor nerve

Unmyelinated nerve fibers of the oculomotor nerve have occasionally been observed in experimental animals with the use of electron microscopes, but no details concerning normal oculomotor nerves in humans have been published. We measured and analyzed unmyelinated nerve fibers in the human oculomotor nerve with an image analyzer and a computer, using a new staining method, the Luxol fast blue-periodic acid-Schiff-hematoxylin (LPH) discriminative staining method which is the only one suitable for morphometric research on nervous tissues. We studied the numbers and transverse areas of unmyelinated fibers of the oculomotor nerve in 20 cadavers. The number of unmyelinated axons did not change with age, but the mean transverse area decreased with age. These fibers were distributed diffusely in the transverse area of the oculomotor nerve, not localized in any part of the nerve. These findings may be important for the analysis of clinical and neurological signs in relation to aging and ophthalmologic functions.     

A connecting branch between the musculocutaneous nerve and the median nerve

We report here a connecting branch between the musculocutaneous and the median nerves in a 42 years old male cadaver. The connecting branch was 8 cm in length and 3 mm in width. One of the brachial veins and the brachial artery were located between the roots of the median nerve and the second brachial vein was present between the connecting branch and the median nerve. These kinds of variations may effect the venous return and may cause edema in the upper extremities. Additionally, variations of these nerves have an importance during operations of this region.     

Formation and distribution of the sural nerve based on nerve fascicle and nerve fiber analyses

The formation and distribution of the sural nerve are presented on the basis of an investigation of 31 legs of Japanese cadavers using nerve fascicle and fiber analyses. Nerve fibers constituting the medial sural cutaneous nerve were designated as 'T', whereas those constituting the peroneal communicating branch were designated as 'F'. In 74.2% of cases (23/31), the T and F fibers joined each other in the leg, whereas in 9.7% of cases (3/31) they descended separately. In 16.1% of cases (5/31), the sural nerve was formed of only the T fibers. The sural nerve gave off lateral calcaneal branches and medial and lateral branches at the ankle. The lateral calcaneal branches always contained T fibers. The medial branches consisted of only T fibers, whereas most of the lateral branches consisted of only F fibers (71.0%; 22/31). In addition to the T and F fibers, P fibers, which derived from the superficial and deep peroneal nerves, formed the dorsal digital nerves. The P fibers were entirely supplied to the medial four and one-half toes. However, they were gradually replaced by the T and F fibers in the lateral direction. The 10th proper dorsal digital nerve consisted of T fibers only (38.7%; 12/31), of F fibers only (19.4%; 6/31) or of both T and F fibers (38.7%; 12/31). These findings suggest that the T fibers are essential nerve components for the skin and deep structures of the ankle and heel rather than the skin of the lateral side of the fifth toe. The designation of the medial sural cutaneous nerve should be avoided and only the T fibers are appropriate components for naming as the sural nerve.     

肌皮神经并正中神经及尺神经变异1例

在解剖一具老年男性标本时，见左侧肌皮神经并正中神经及尺神经形态变异(附图)。经查有关文献，此类变异较为少见，现报道如下：     

Unmyelinated nerve fibre analysis of the human lesser splanchnic nerve

The aim of the present study is to analyse unmyelinated nerve fibres of the human lesser splanchnic nerve in relation to the ageing process. With the help of an image-analyser, we examined 30 human lesser splanchnic nerves. The analysis was conducted with the use of a new staining method that makes it possible to discriminate various structures of the nervous tissue. Our report provides for the first time information on the ageing process of the human lesser splanchnic nerve fibres. The results indicate that a decrease in transverse area and perimeter of unmyelinated axons is one of the important changes occurring in the human lesser splanchnic nerve during the ageing process.