索曼中毒运动终板乙酰胆碱酯酶活性和接头传递功能的关系

用大鼠的在体膈肌局部索曼(Soman)中毒法,观察了乙酰胆碱酯酶(ACHE)在运动终板的再生和肌接头传递功能的恢复过程,以及肟类药物(HI-6)对两过程的促进作用。提出终板 AChE 活性与高频间接刺激(100次/秒)引起膈肌强直收缩幅度有一定的关系。中毒早期(30分钟以内)HI-6对索曼抑制的膈肌终板 AChE 有一定的重活化作用,并能相应地恢复肌接头的传递功能。     

神经生长因子对神经损伤后运动终板再生影响的研究——酶组织化学和超微结构观察

本研究采用定位、定量方式钳夹兔右侧坐骨神经,ＮＧＦ组动物于神经损伤处局部喷布蛇毒神经生长因子（ｎｅｒｖｅｇｒｏｗｔｈｆａｃｔｏｒ,ＮＧＦ）,对照组动物于同部位给予等量生理盐水。对胫骨前肌中的红肌、白肌和中间型肌纤维运动终板乙酰胆碱酯酶（ＡＣｈＥ）活性和超微结构改变进行观察。结果表明,神经损伤早期,ＡＣｈＥ活性持续下降,超微结构显示逐渐变性。第４周末,ＮＧＦ组运动终板ＡＣｈＥ活性和超微结构恢复正常。第８周末,对照组运动终板酶活性和超微结构才基本恢复正常。本研究结果提示,周围神经损伤后,外源性ＮＧＦ能促进运动神经元轴突再生,最终促进运动终板结构和功能恢复     

慢性缺氧对大鼠膈肌组织化学和超微结构影响的研究

研究慢性缺氧和参麦注射液治疗对大鼠膈肌组织化学和超微结构的影响,结果显示：缺氧使膈肌ＳＤＨ活性降低,Ⅰ类纤维极显著减少,运动终板ＣｈＥ活性极显著降低,线粒体肿胀变性,神经肌肉运动终板突触前部囊泡减少,突触间隙模糊,终板模电子密度降低;参麦治疗可恢复缺氧膈肌的ＳＤＨ活性及Ⅰ类纤维数目,显著提高终板ＣｈＥ活性,线粒体结构恢复正常,运动终板突触前部囊泡丰富,突触间隙清晰,终板膜电子密度正常。表明慢性缺氧降低膈肌有氧氧化能力,影响其能量代谢及神经冲动的传递,从而减弱其收缩力,而参安治疗可改善缺氧造成的上述损害,为其临床应用提供了实验医学依据。     

骨骼肌运动终板和神经纤维的酶组织化学及镀银双重显示

本文用Ｋａｒｎｏｖｓｋｙ－Ｒｏｏｔ的方法显示骨骼肌（如股肌等）运动终板的胆碱酯酶（ＣｈＥ）,然后进行镀银。结果发现未经镀银的运动终板胆碱酯酶呈棕红色,加硝酸银浸染的运动终板呈棕褐色与神经纤维连接。此方法简便、易行,且运动终板及神经纤维显示清晰。材料和...     

大鼠膈肌去神经后终板形态结构及胆硷酯酶活力在体与在器官培养下的变化的比较

在体骨骼肌去神经后,终板形态结构退变, 胆硷酯酶活力迅速下降。而Miledi (1962)用器官培养法培养大鼠膈肌5、6天,在测试到肌纤维终板外乙酰胆硷敏感性增加的同时,观察到终板上仍有胆硷酯酶活力。Peterson和Crain(1972)培养啮齿类动物的成年骨骼肌肌纤维残段2、3月后,也观察到终板上有明显的胆硷酯酶活力。可是这些资料均未有意识地与在体正常终板酶活力或去神     

地塞米松对大鼠坐骨神经损伤后各型肌纤维运动终板恢复作用的实验研究

本实验使用１２０只Ｗｉｓｔａｒ系大鼠,采用定位、定量、定时的方法压挫坐骨神经后,给予治疗剂量的地塞米松,动态地观察损伤后红、白、中间肌纤维运动终板ＡＣｈＥ的酶组织化学及各型肌纤维运动终板超微结构的变化。结果提示,早期适量应用地塞米松对周围神经损伤后运动终板的恢复有促进作用。     

鼠胚胎运动神经元胫神经内种植的观察

目的：观察胚胎运动神经元移植至入肌点前神经内的存活情况。方法：取孕１２天胎鼠运动神经元,种植于成鼠入肌点前胫神经内,于实验后９、２２周取材作尼氏、Ｗｅｉｌ氏、肌动蛋白免疫组织化学、ＡＴＰ酶组织化学及氯化金染色观察。结果：胚胎运动神经元在周围神经干内能存活和发育,并减缓失神经骨骼肌及运动终板的萎缩     

大鼠快、慢肌终板乙酰胆碱受体的比较及去神经后的变化

经化学方法合成的辣根过氧化酶-α-银环蛇毒复合物(HRP-α-BuTx)能专一地结合乙酰胆碱受体,从而显示肌纤维终板区,可作组织化学观察,DAB 棕色沉淀的深度反映了 ACh受体的密度。实验结果表明,大白鼠趾伸长肌的终板 ACh 受体密度无例外的比比目鱼肌的板终 ACh 受体密度高;正常终板具有很多分枝的沟糟结构,DAB 沉淀分布于沟糟内壁。切断神经后终板结构变得不甚清晰。与正常相比,去神经 SOL 的终板 ACh 受体密度显著升高,去神经 EDL 的终板 ACh 受体密度虽也有升高,但由于 EDL 的终板 ACh 受体密度本来较高,差别没有 SOL 的显著。     

保存原来神经支配的快肌和慢肌在长期刺激影响下的精细结构变化

本文以模拟慢肌神经发放模式的刺激(简称慢型刺激)连续刺激大白鼠伸趾长肌(EDL)28—30天和以模拟快肌神经发放模式的刺激(简称快型刺激)连续刺激比目鱼肌(SOL)23—26天,然后对其肌纤维的终板区进行电镜观察。发现受长期慢型刺激的 EDL 肌纤维,除 Z-带宽度接近正常 SOL 肌纤维的 Z-带宽度和线粒体(尤其是肌膜下)明显增多外,神经末梢的形态,特别是突触后褶的稀、密程度也变得和正常 SOL 肌纤维的相似,并在约40%的终板区内看到卫星细胞。就是说,肌纤维的精细结构发生了由原来的快肌型向慢肌型的根本转变。与此相反,在长期受快型刺激的 SOL 肌纤维,则看不到上述超微结构特征由原来的慢肌型向快肌型的转变。上述结果与我们在双神经支配的肌纤维上所作的观察可以互相佐证,即比目鱼肌纤维在接受外加 EDL 神经支配后组织化学和精细结构类型不变,而 EDL 纤维在接受外加的 SOL 神经支配后则组织化学和精细结构类型发生彻底的改造。     

声带及其保护

声带是人类发声的主要结构,从极轻微的声嘶到完全失声,多为声带病变或其他病因使声带的正常运动发生障碍所致。从某种程度上讲,了解声带及发音的有关知识,对提高我们预防声嘶,保护声带有一定的帮助。１　声带的结构及位置声带位于喉腔假声带（室带）下方,左右各一,由声韧带、肌肉和粘膜组成,前起甲状软骨板交角内面。间接喉镜下观察,声带呈白色带状,边缘整齐,由于其后端附着于杓状软骨的声带突,故可随声带突的运动而张开或闭合。声带张开时,出现一个等腰三角形的裂隙,称为声门裂,简称声门,空气由此进出,亦为喉部最窄处。声…     

CELLULAR DISTRIBUTION OF 16S ACETYLCHOLINESTERASE

Multiple molecular forms of acetylcholinesterase (AChE; EC 3.1.1.7), in crude extracts of various tissues from the rat, were distinguished by velocity sedimentation analysis on linear sucrose gradients. Skeletal muscle samples containing end-plate regions showed three different forms of AChE with apparent sedimentation coefficients of 16, 10 and 4s. The 16s form was not detected in non-innervated regions of skeletal muscle, large intestine smooth muscle, whole brain tissue, red blood cells or plasma. Spinal cord, a predominantly motor cranial nerve and mixed (sensory and motor) peripheral nerves contained 16, 10, 6.5 and 4S AChE. Ventral motor roots, supplying the sciatic nerve, contained these four forms of the enzyme, while corresponding dorsal sensory roots were devoid of the 16S form. The 16s-AChE confined to ventral roots can be attributed totally to motor neurons and not to Schwann cells composing these roots. Whether the 16s-AChE presently found in motor nerves has chemical identity with that found at motor end-plates is the basis of future experiments.     

Histological study of motor innervation to long nuclear chain intrafusal fibers in the muscle spindle of the cat

Several muscle spindles of the cat tenuissimus muscle were cut in serial, 1-micron thick transverse sections and stained with toluidine blue in search for long nuclear chain intrafusal muscle fibers. Five complete poles of the long chain fibers were located. Each fiber pole displayed one plate-type motor ending situated in the extracapsular fiber region. The endings were supplied by myelinated motor axons that originated from intramuscular nerve fascicles containing motor axons to extrafusal muscle fibers. One of the endings was innervated by a collateral from a motor axon that supplied an extrafusal end-plate. Ultrastructurally, the long chain endings resembled extrafusal end-plates. They were more complex, in terms of prominence of sole-plate and degree of post-junctional folding, than any other intrafusal ending present in the spindles. The motor endings of the long chain fibers were assumed to be the terminals of static (fast) skeletofusimotor axons, which preferentially innervate the longest nuclear chain fibers of cat muscle spindles.     

EFFECTS OF BOTULINUM AND TETANUS TOXINS ON CHOLINE ACETYLTRANSFERASE ACTIVITY IN SKELETAL MUSCLE IN THE MOUSE

Abstract— The effects of botulinum and tetanus toxins on the activity of choline acetyltransferase present in the motor nerve terminals of fast and slow skeletal muscle in the mouse were investigated. There was no change in the activities of choline acetyltransferase in either muscle after the injection of botulinum toxin but tetanus toxin caused a rise in the activity of the enzyme in fast muscle. Botulinum toxin is known to inhibit the release of acetylcholine and whilst neuromuscular transmission is blocked the motor nerves sprout and form new end-plates. Tetanus toxin has been shown to cause hyperactivity of motor neurons. The nerve growth caused by the botulinum toxin did not result in increased choline acetyltransferase levels in the muscles, whereas the synaptic hyperactivity caused by tetanus was associated with increased enzyme levels.     

A NOTE ON THE ACTION OF CURARE,ATROPINE, AND NICOTINE ON THE INVERTEBRATE HEART

1. The alkaloids (curare, atropine, and nicotine) in molluscs and arthropods stimulate and paralyze the central nervous system and peripheral (visceral) ganglia, but do not paralyze the motor nerve endings to skeletal or visceral muscle. 2. They stimulate and paralyze the denervated heart. 3. They paralyze or block the cardioinhibitory nerves, but not the cardioaccelerator nerves. 4. In the Limulus heart these drugs act primarily on the heart ganglion, not on the heart muscle or the intrinsic motor nerve fibers.     

OBSERVATIONS ON THE FINE STRUCTURE AND CYTOCHEMISTRY OF MOUSE AND HUMAN INTERCOSTAL NEUROMUSCULAR JUNCTIONS

The fine structure of the mouse and human intercostal muscle neuromuscular junction was studied after brief fixation in a new formol-sucrose fixative. This primary formalin fixation was followed by brief postosmication in buffered 1 per cent osmium tetroxide. Muscle blocks were embedded in methacrylate or Epon 812 epoxy resin. Marked similarities between mouse and human motor end-plates were observed. Neuromuscular junctions from both mouse and human intercostal muscle showed synaptic vesicles, primary and secondary synaptic clefts, and layered differentiation of the amorphous surface material (ASM) present on the surface of the Schwann cell plasma membrane and on the muscle surface membrane in the region of the neuromuscular junction. An attempt to stain the ASM with lead was unsuccessful. Observations on thick and thin plastic-embedded sections stained by PAS after diastase digestion showed that the ASM within the subneural apparatus is PAS positive. Alcian blue stained the endoneurium and perineurium of peripheral nerve bundles and portions of the end-plates. The similarity of the PAS-positive ASM to other basement membranes described in other sites is discussed and its possible physiologic significance within the subsynaptic apparatus is considered.     

刺猬的皮肌及其神经支配

刺猬的皮肤,包括皮肤肌和皮下脂肪,是一个质量很大的器官,平均占体重43形,最多可达57％以上。刺猬的皮肌,如果不是动物界中最发达的,也是非常发达的,尤其环状皮肌带约占体重11％(赵以炳等1958)。在功能上,刺猬的皮肌是重要的生理性体温调节器官,背面带针刺的部分有保温御寒作用,腹部有散热机能(赵以炳等1950a)。清醒的刺猬当遇到强敌或其它干扰时,常蜷缩成带剌的球。不活动的冬眠刺猬也取同样姿势,以防侵害。可以说,蜷缩是一种主动的保护性行为,这种强烈的蜷缩主要是由于环状皮肌带持续有力的收缩。尤其令人惊奇的是冬眠时的蜷缩,这是在一般生理活动明显降低的     

Size-related differences in the branching pattern of the motor nerve terminals in triangularis sterni muscle of the mouse

A light microscopy morphometric study was performed in singly innervated synaptic areas of the triangularis sterni muscle of the normal adult Swiss mouse. Investigating mechanisms of the motor nerve growth control, we tested the hypothesis that significant differences in the nerve terminal branching pattern can be detected between different populations of nerve endings classified according to their arborization complexity or size. The main observations of this morphometric study are first, that the mean segment length of the terminal arborization between branch points behaves as an independent variable from the remaining parameters; the mean value of this parameter did not change in nerve endings of differing size and complexity. Secondly, the increase in size of the nerve endings is accompanied by a significant reduction in the mean length of the distal free-end segments. Results are discussed in the context of the possible regulatory mechanisms governing nerve terminal growth and remodelling.     

Respiratory activities of intralaryngeal branches of the recurrent laryngeal nerve

To distinguish experimentally between motor nerve activity destined for vocal cord abductor muscles and that bound for muscles that adduct the cords, we recorded efferent activities of intralaryngeal branches of the recurrent laryngeal nerve (RLN) in decerebrate, vagotomized, paralyzed, ventilated cats. Activities of the whole RLN and phrenic nerve were also recorded. Nerve activities were assessed at several steady-state end-tidal O2 and CO2 concentrations. The nerve to the thyroarytenoid (TA) muscle, a vocal cord adductor, was only slightly active under base-line (normocapnic, hyperoxic) conditions but in most cats developed strong activity during expiration in hypocapnia or hypoxia. In severe hypocapnia, phasic expiratory TA activity persisted even during phrenic apnea, indicating continuing activity of the respiratory rhythm generator. The nerve to the posterior cricoarytenoid (PCA) muscle, the vocal cord abductor, was always active in inspiration but often showed expiratory activity as well. This expiratory activity was usually enhanced by hypercapnia and often inhibited by hypoxia. The results are consistent with previous electromyographic findings and emphasize the importance of distinguishing abductor from adductor activity in studies of laryngeal control.     

Activity-dependent plastic changes in the motor nerve terminals of the adult rat

Summary— Small and short-lasting physiologic variations in the locomotor activity of normal adult rats can induce remodelling in the motor nerve endings of the fast extensor digitorum longus muscle. The specificity and relative importance of the different plastic adaptations occurring in the presynaptic axonal tree have been studied, in silver impregnated nerve endings, by using an automatic image analysis treatment of the nerve terminals' geometric properties and a discriminant analysis of the morphometric parameters. Changes observed, like selective length variations in certain terminal segments and positional rearrangements, agree with a mechanism of neural connectivity regulation in the adult that arises as a consequence of normal neuromuscular activity.     

Uniform Staining of Nerve Endings in Skeletal Muscle with Gold Chloride

Skeletal muscle, teased into strips several millimeters long and 1 mm or less thick, is fixed in a 3:1 mixture of lemon juice and formic acid until transparent. The tissue is compressed between folds of absorbent material to remove excess fixative and impregnated for 10 min in a volume of 1% gold chloride equal to the volume of muscle. After removing excess gold chloride, reduction is effected. Method a. Exposure to 25% formic acid in the dark for 6 hr. When intramuscular nerves are visible, the muscle is further teased with glass instruments. Reduction is continued for an additional 18 hr in 25% formic acid, and the tissue is cleared in glycerol for 24 hr. Method b. Exposure to intense artificial visible light while the tissue is just immersed in distilled water at 37° C. Colour develops in the nerve endings as in a photographic print. When nerves only are stained (approximately 0.5 hr), the lamp is removed and microdissection at room temperature commenced. When nerve endings in muscle spindles are just visible (approximately 1 hr), the distilled water is replaced by glycerol. After either method of reduction, areas of motor end-plates and individual sensory receptors are isolated by microdissection. Preparations are mounted in a small drop of glycerol, considerable pressure is applied to the cover slip, and the cover ringed with a sealing fluid.