猫外侧颈核内脊颈纤维终末与颈丘脑投射神经元间的突触联系

本实验采用顺行溃变和ＨＲＰ逆行追踪结合的方法研究了猫脊颈丘脑通路在外侧颈核水平的突触联系。在脊髓颈段刀切损毁一侧背外侧索后将ＨＲＰ注射于对侧丘脑腹后外侧核。在电镜下于损毁同侧的外侧颈核内可见到下列突触联系：（１）溃变的轴突终末与ＨＲＰ标记的树突形成的轴—树突触；（２）溃变的轴突终末与标记的神经元胞体形成的轴—体突触；（３）溃变的轴突终末及正常的轴突终末与标记的中央树突形成的汇聚型突触复合体；（４）溃变的轴突终末与非标记的神经元树突和胞体形成的轴—树和轴—体突触；（５）正常轴突终末与标记的神经元树突和胞体形成的轴—树和轴—体突触。此外，在正常的神经元成分之间还可见到许多类型的突触。     

猫颈外侧核内颈丘脑投射神经元的超微结构及其突触联系

猫颈外侧核接受来自同侧脊髓后角的脊颈束 ,其传出纤维投射至对侧的丘脑腹后外侧核。该通路与传导皮肤的伤害性信息有关。本文采用 HRP逆行追踪技术 ,在电镜水平研究了猫颈外侧核内颈丘脑投射神经元的超微结构及其突触联系。将 HRP注入猫左侧丘脑腹后外侧核 ,经颈总动脉灌流固定 ,TMB法呈色反应。选取右侧颈外侧核内有 HRP标记的细胞制备电镜标本 ,透射电镜观察。结果发现 ,颈外侧核内出现大、中型 HRP标记神经元 ,细胞核为卵圆形 ,可见核仁 ,胞浆丰富 ,含有多量的线粒体等细胞内器 ,HRP反应产物散在于其中。在颈丘脑投射神经元胞体的周围见有 HRP标记的树突以及非标记的轴突、神经元胞体及树突。 HRP标记的颈丘脑投射神经元作为突触后成分与其他成分形成轴 -树突触 ,轴 -体突触 ,轴 -轴 -体突触及轴 -树突触复合体。这些结果提示 :颈丘脑投射神经元接受广泛的传入联系     

大鼠脊髓向中央颈核和外侧颈核的投射——PHA-L顺行追踪研究

将菜豆白细胞凝集素(PHA-L)分别注入下颈髓、胸髓、腰髓和骶髓等不同脊髓节段,顺行追踪脊髓向中央颈核和外侧颈核的投射。观察结果表明,脊髓不同节段注入PHA-L,在中央颈核和外侧颈核均可见到标记末梢;比较各节段脊髓的投射分布,未能发现明显的定位关系。一侧脊髓灰质注入,在两侧中央颈核均观察到标记末梢,但主要见于同侧;外侧颈核的标记末梢仅见于同侧。结果提示,各节段脊髓均发出纤维投射到同侧中央颈核和外侧颈核。     

大鼠中央杏仁核向迷走背核复合体的直接投射──HRP逆向追踪和形态计量学研究

依据细胞大小、形态和密度的不同，把中央杏仁核分为５个亚区：即内侧亚区（ＣＭ）、腹侧亚区（ＣＶ）、中间亚区（ＣＩ）、外侧亚区（ＣＬ）和外侧囊亚区（ＣＬＣ）。ＣＬ体积最大（０．１０３ｍｍ３），细胞总数最多（８７１１个），细胞中等大小，细胞密度最高（８．６４ｘ１０４个／ｍｍ３）；ＣＩ体积最小（０．０１６ｍｍ３）、细胞总数最少（１０７５个），但细胞最大；ＣＬＣ细胞密度最低（４．５４×１０４个／ｍｍ３），细胞也最小；ＣＭ和ＣＶ的各项参数介于上述最高和最低参数之间。将ＨＲＰ注入一侧迷走背核复合体的上部后，在同侧中央杏仁核各亚区内标记细胞的平均数及与其神经元总数的百分比为：ＣＭ：３７２１个，７０％；ＣＶ：１４１２个，３５％；ＣＩ：８３个，８％；ＣＬ：３９１个，５％。ＨＲＰ注射入闩下部后，数据为：ＣＭ：１８２２个，３４％；ＣＶ：６０６个，１５％；ＣＩ：６８个，６％；ＣＬ：２９５个，３％。本研究表明：向迷走背核复合体直接投射的神经元是中央杏仁核内较小的细胞。投射的主要亚区为ＣＭ和ＣＶ，两亚区向闩上部的纤维投射明显多于向闩下部的投射。     

丘脑室旁核形态和功能研究进展

丘脑室旁核（PVT）为丘脑中线核团的重要组成部分,是多种行为的中继传导核团及整合中心,参与动物觉醒、摄食、成瘾、奖赏、恐惧记忆等多种行为的调节。PVT内主要分布着表达囊泡谷氨酸转运体-2（VGluT2）的谷氨酸能兴奋性神经元,却无γ-氨基丁酸（GABA）能抑制性神经元。基于PVT的复杂功能与其内神经元相对单一的兴奋性属性,有必要对PVT内兴奋性神经元进行分类。在本综述中,我们主要对PVT的形态及电生理特点、传入和传出联系、前后两段的形态和功能差异进行总结,并以纤维联系和神经化学性质作为分类标准对PVT的兴奋性神经元进行分类,以便为阐明PVT的复杂功能提供帮助。     

杏仁复合体皮质内侧核群与基底外侧核群的皮质下传入性联系——逆行HRP法

用逆行HRP标记法研究了大白鼠杏仁复合体皮质内侧核群及基底外侧核群的皮质下传入性联系。分别对丘脑、下丘脑、中脑、脑桥等部向此二核群投射的核团做了观察和讨论。     

大鼠伏隔核儿茶酚胺能传入纤维的脑干起源—逆行荧光标记法与荧光组化法结合研究

应用逆行荧光标记与Faglu荧光组化相结合技术,探索了大鼠伏隔核CA能传入纤维的脑干起源。大鼠52只,分三组进行实验。单侧注射组,分别将荧光素PI、DAPI或Bb注入一侧伏隔核后,灌流前作优降宁和L-多巴胺腹腔注射,继用Faglu程序处理切片。结果在同侧的A_(10)、A_9、A_8、A_6、A_2和A_1中,发现为荧光素逆行标记的CA神经元;在对侧的A_(10)、A_9、A_2和A_1中,亦见少量的上述神经元。在以PI-Bb或PI-DAPI配对的双侧注射组,在A_(10)和A_9群中可见少量荧光逆行双标记的CA神经元。表明伏隔核除主要接受同侧脑干A_(10)、A_9、A_8、A_6、A_2和A_1的CA传入纤维外,尚接受对侧A_(10)、A_9、A_2和A_1的少量CA传入纤维。此外,在A_(10)和A_9中,存在着少量向双侧伏隔核发出分叉投射的CA神经元。     

面神经颈支和下颌缘支的临床解剖学研究进展

目的:总结面神经颈支和下颌缘支的应用解剖研究成果,了解其走行及变异情况,以利于手术中对其保护,避免手术损伤.方法:查阅近年来国内外有关面神经颈支和下颌缘支的应用解剖及其临床意义方面的文献资料,并进行汇总分析.结果:面神经颈支位置恒定,行程短,可作为逆行分离面神经干的解剖标志.面神经下颌缘支变异较多,行程长,在手术中易受损伤.结论:通过对面神经颈支和下颌缘支的临床解剖学研究,为头颈部手术路径的设计提供了新的解剖标志,为手术中避免上述神经的损伤提供帮助.     

大鼠三叉神经中脑核神经元中枢突在脑干内投射的光、电镜观察(中脑核-丘脑投射通路研究之一)

为了进一步搞清三叉神经中脑核(Vine)向丘脑的投射通路,本文首先用HRP跨节追踪技术在大鼠研究了接受咬肌本体觉传入的Vme神经元中枢突在脑干内的终止情况。结果证明它除终止于三叉运动核及三叉上核外,主要终止于面神经核水平的三叉神经脊束核吻侧亚核背内侧部(Vodm)及邻接的外侧网状结构(LRF)。在电镜观察到Vme神经元中枢突终末在Vodm区主要和该区内的树突形成突触。并观察到这些终末接受另外来源的神经终末的突触前控制。     

Changes in synaptic effectiveness of myelinated joint afferents during capsaicin-induced inflammation of the footpad in the anesthetized cat

The present series of experiments was designed to examine, in the anesthetized cat, the extent to which the synaptic efficacy of knee joint afferents is modified during the state of central sensitization produced by the injection of capsaicin into the hindlimb plantar cushion. We found that the intradermic injection of capsaicin increased the N2 and N3 components of the focal potentials produced by stimulation of intermediate and high threshold myelinated fibers in the posterior articular nerve (PAN), respectively. This facilitation lasted several hours, had about the same time course as the paw inflammation and was more evident for the N2 and N3 potentials recorded within the intermediate zone in the L6 than in the L7 spinal segments. The capsaicin-induced facilitation of the N2 focal potentials, which are assumed to be generated by activation of fibers signaling joint position, suggests that nociception may affect the processing of proprioceptive and somato-sensory information and, probably also, movement. In addition, the increased effectiveness of these afferents could activate, besides neurons in the intermediate region, neurons located in the more superficial layers of the dorsal horn. As a consequence, normal joint movements could produce pain representing a secondary hyperalgesia. The capsaicin-induced increased efficacy of the PAN afferents producing the N3 focal potentials, together with the reduced post-activation depression that follows high frequency autogenetic stimulation of these afferents, could further contribute to the pain sensation from non-inflamed joints during skin inflammation in humans. The persistence, after capsaicin, of the inhibitory effects produced by stimulation of cutaneous nerves innervating non-inflamed skin regions may account for the reported reduction of the articular pain sensations produced by trans-cutaneous stimulation.     

纤维肌痛综合征疼痛机制的研究进展

纤维肌痛综合征（FMS）是风湿病门诊中的常见病,其疼痛的病因、发病机制尚未完全阐明。最新的研究热点集中于中枢神经系统疼痛传导通路的异常,如中枢致敏和疼痛抑制不充分等。外周组织伤害性传入刺激也作为相关因素引发和／或维持中枢致敏状态,同时神经内分泌和应激反应异常在FMS发病中也起重要作用。     

窦口鼻道复合体的应用解剖

目的：确定窦口鼻道复合体的境界，为临床在内窥镜下施行上颌窦手术提供解剖学依据。方法：在６０例成人鼻腔外侧壁的标本上，测量半月裂、钩突、筛泡、额鼻管和筛漏斗的有关数据。并观察了它们相互间的关系以及上颌窦的自然开口。结果：半月裂、钩突、筛泡、额鼻管的长度分别为１５．０ｍｍ，１８．３ｍｍ，１６．２ｍｍ和５．９ｍｍ；钩突与筛泡的高度分别为６．９ｍｍ和５．８ｍｍ；筛漏斗宽３．９ｍｍ、深３．７ｍｍ。上颌窦自然开口９８％在半月裂内，其中６０％位于半月裂后部、３３％位于中部、５％位于前部、１例变异。结论：窦口鼻道复合体的形态和病变与鼻窦炎的发病有直接联系     

Autogenic and nonautogenic sensorimotor actions in the control of multiarticulate hand movements

Summary The relationship between the size of an afferent volley and the size of the short-latency cerebral potential produced by the volley is not linear for purely cutaneous afferents, mixed cutaneous and muscle afferents or purely muscle afferents. The cerebral potential approaches a maximum when the responsible afferent input is 50% of maximum, while cerebral potentials of about half maximal size require an afferent volley of about one fifth of maximum. The relationship for sural (cutaneous) afferents rises less steeply. This saturation probably results from the convergence of the most rapidly conducting components in each afferent volley at sequential subcortical relay nuclei. The present data is compared with published data from animal experiments.     

中介体复合物在真核细胞转录调控中的研究进展

中介体复合物作为转录过程中的重要辅因子,广泛参与了RNA聚合酶Ⅱ(RNA polymerase Ⅱ,pol Ⅱ)调控的转录激活与抑制过程,其结构在进化上具有保守性.然而,由于中介体复合物结构与组成的复杂性和可变性,我们对其调控基因表达的机制仍知之甚少.最近研究显示中介体复合物多种转录活性的调节与转变,可能与细胞周期素依赖性激酶8(cyclin-dependent kinase 8,CDK8)亚模块的可逆性结合与修饰密切相关.     

Olfactory sensory neurons in the sea lamprey display polymorphisms

Repair strategies for spinal cord injury often focus on promoting regeneration of injured axons and stimulating subsequent functional recovery. Although many of these strategies have proven their merits, less is known about potential unwanted side-effects, such as sprouting of nociceptive CGRP immunoreactive axons, which may bring about pain-related behavior. Sprouting of CGRP axons into lesion sites spontaneously occurs after spinal cord injury (SCI). Using L1-deficient mice we show a reduction of such CGRP growth response. This reduction was specific for CGRP axons since the overall neurofilament positive fibre in-growth into the spinal lesion site was not affected. Our results may have important implications on the development and assessment of repair strategies that should not only stimulate functional recovery, but also prevent the development of pain or autonomic dysreflexia.     

Stimulation of the middle meningeal artery leads to Fos expression in the trigeminocervical nucleus: a comparative study of monkey and cat

The pain of a migraine attack is often described as unilateral, with a throbbing or pulsating quality. The middle meningeal artery (MMA) is the largest artery supplying the dura mater, is paired, and pain-producing in humans. This artery, or its branches, and other large intracranial extracerebral vessels have been implicated in the pathophysiology of migraine by theories suggesting neurogenic inflammation or cranial vasodilatation, or both, as explanations for the pain of migraine. Having previously studied in detail the distribution of the second order neurons that are involved in the transmission of nociceptive signals from intracranial venous sinuses, we sought to compare the distribution of second order neurons from a pain-producing intracranial artery in both monkey and cat. By electrically stimulating the middle meningeal artery in these species and using immunohistochemical detection of the proto-oncogene Fos as a marker of neuronal activation, we have mapped the sites of the central trigeminal neurons which may be involved in transmission of nociception from intracranial extracerebral arteries. Ten cats and 3 monkeys were anaesthetised with α-chloralose and the middle meningeal artery was isolated following a temporal craniotomy. The animals were maintained under stable anaesthesia for 24 h to allow Fos expression due to the initial surgery to dissipate. Following the rest period, the vessel was carefully lifted onto hook electrodes, and then left alone in control animals (cat n = 3), or stimulated (cat n = 6, monkey n = 3). Stimulation of the left middle meningeal artery evoked Fos expression in the trigeminocervical nucleus, consisting of the dorsal horn of the caudal medulla and upper 2 divisions of the cervical spinal cord, on both the ipsilateral and contralateral sides. Cats had larger amounts of Fos expressed on the ipsilateral than on the contralateral side. Fos expression in the caudal nucleus tractus solitarius and its caudal extension in lamina X of the spinal cord was seen bilaterally in response to middle meningeal artery stimulation. This study demonstrates a comparable anatomical distribution of Fos activation between cat and monkey and, when compared with previous studies, between this arterial structure and the superior sagittal sinus. These data add to the overall picture of the trigeminovascular innervation of the intracranial pain-producing vessels showing marked anatomical overlap which is consistent with the often poorly localised pain of migraine.     

神经元去极化反跳现象的研究进展

正神经元受刺激后产生动作电位,并将该刺激信号传递给其它的神经元,进而影响整个神经回路。这种接受去极化刺激后能够产生动作电位的特性,是判断细胞是否具有兴奋性的标准。然而亦有研究表明,神经元在接受超极化刺激后也能爆发动作电     

痛觉的脑成像研究进展

痛觉是日常生活中最重要的感觉之一,痛觉的机理非常复杂.随着20世纪90年代各种脑成像技术的成熟,现在人们对于大脑的痛觉处理过程有了更好的理解.综述了痛觉脑成像的研究方法,包括电生理技术和脑功能成像技术,重点关注了这些技术在痛觉研究方面的相关成果.指出了解剖学上的痛觉处理机制.并分析了目前痛觉脑功能成像研究存在的缺陷和不足.     

Histological anatomy of the triangular fibrocartilage complex of the human wrist

The triangular fibrocartilage complex (TFCC) was studied in serial histological sections of the human wrist to reveal its three-dimensional fine structure. The TFCC consisted of a fibrocartilaginous disc proper and other fibrous components. Three-dimensionally, the distal portion of the TFCC had a hammock-like contour that partially surrounded the carpus; while the proximal ligamentous portion corresponding to the radioulnar ligament connected the radius to the ulna. The radioulnar ligament originated at the ulna from both the fovea and the basistyloid. The fibres first gathered and then bifurcated palmarly and dorsally, enclosing and partially coalescing with the proximal side of the disc before inserting around the distal rim of the sigmoid notch of the radius. The meniscus homologue, which corresponded to the ulnar internal wall of the wrist joint, was derived from a loose synovial fold adapting to the stresses from radioulnar deviation. The distal side of the disc consisted of a dense population of chondrocytes in a collagen matrix, while the proximal side was rather rich in fibres directed radioulnarly. Inside the TFCC were loose connective tissues. The histological arrangement of the TFCC is compatible with its function of supporting the carpus, stabilizing the joints and allowing smooth motion of the wrist.