5一羟色胺能神经对横断损伤脊髓的再支配-脊髓内移植研究

用成年SD大鼠20只在脊髓的低位胸髓完全横断损伤,分别在1周和1月后,用富含5一羟色胺(5—HT)神经元的胚鼠脑干中缝组织悬液植人损伤尾侧的脊髓内,动物存活2个月,脊髓作5—HT免疫组化观察.结果:(1)胚5-HT能神经元能在成年大鼠脊髓内存活,5-HT纤维大多在灰质中延伸并向靶区分布,(2)损伤后1周移植组的5-HT能神经元存活量,5-HT纤维在宿主脊髓内延伸距离,以及5-HT末梢再分布的密度都优于损伤后1月移植组.     

茶黄烷醇对离体缺血再灌注鼠心心律失常的作用

本研究旨在探讨茶黄烷醇(TF)对离体缺血再灌注鼠心心律失常的作用。结果表明,对照组缺血后再灌注初期心律失常发生率高达91.67%(11/12),显著高于TF组(P<0.005),TF组心律失常发生率仅为23.08%(3/13);对照组心律失常持续时间平均为27.91±6.94min,TF组平均为9.83±6.21min,两组比较差异显著(P<0.001)。上述结果表明TF具有显著的抗缺血再灌性心律失常作用。     

Influences of contralateral nerve and skin stimulation on neurones in the substantia gelatinosa of the rat spinal cord

Stimulation of high threshold A delta and C fibre peripheral afferents inhibits dorsal horn cells on the other side of the spinal cord. The substantia gelatinosa (SG) is an area full of interneurones known to have commissural connections across the spinal cord. The role of SG in this contralateral inhibitory pathway is investigated here. Forty-three SG cells were recorded in the lumbar dorsal horn of decerebrate spinal rats. Their ipsilateral excitatory receptive fields and responses to sciatic nerve stimulation were recorded. Repetitive electrical stimulation was then applied to the contralateral sciatic nerve. Eight (19%) units were excited by such stimulation. A brief tetanus was followed by an increase of ongoing activity lasting 30 s to 10 min. These cells did not, however, have excitatory contralateral fields. A small separate group of 4 cells (9%) were mildly inhibited by heating or pinching the contralateral limb. The significance of contralateral excitation of some SG cells is discussed in the light of the predominantly inhibitory contralateral effect on dorsal horn cells in laminae 4 and 5. It is suggested that some SG cells may be inhibitory interneurones in their effect on deeper cells.     

内吗啡肽-1对成年大鼠脊髓胶状质内突触传递的抑制作用强于内吗啡肽-2(英文)

本实验采用全细胞电压钳记录方法,研究了内吗啡肽1(EM1)和内吗啡肽2(EM2)对脊髓背角胶状质神经元突触传递的抑制性作用。EM1(1μmol/L)和EM2(1μmol/L)都能够显著抑制微小兴奋性突触后电流(mEPSCs)和微小抑制性突触后电流(mIPSCs)的频率而不改变其幅值。这种抑制作用能被μ受体选择性拮抗剂βfunaltrexamine(βFNA,10μmol/L)阻断。值得注意的是,EM1对mEPSCs和mIPSCs的频率的抑制作用强于EM2。上述结果提示在脊髓胶状质,内吗啡肽通过激活突触前膜上的μ受体,抑制兴奋性和抑制性的突触传递;与EM2相比,EM1可能是脊髓水平的更强效的内源性镇痛剂。     

大鼠腰髓背角星形胶质细胞及神经元对一侧胫、腓骨骨折的反应及其相互关系

目的 研究大鼠脊髓内星形胶质细胞及神经元对一侧胫、腓骨骨折的反应及相互关系。方法 应用细胞免疫组织化学方法，观察脊髓内胶质原纤维酸性蛋白(GFAP)、Fos蛋白双标记以及蛋白激酶C(PKC)在左侧胫、腓骨骨折后不同时程的表达变化。结果 1．左侧胫、腓骨骨折后，GFAP阳性反应产物主要分布于同侧腰髓背角的星形胶质细胞胞浆，Fos阳性产物在其胞核也有表达，且以浅层为主，神经元的胞核也有Fos阳性产物；2．Fos—LI神经元与GFAP／Fos-LI星形胶质细胞的分布基本一致，两者关系密切；3．GFAP／Fos—LI星形胶质细胞表达高峰期在骨折后45min，而Fos—LI神经元的表达高峰期在骨折后90min；PKC—LI星形胶质细胞出现及达到高峰的时间比PKC—LI神经元要早。结论 腰髓背角的星形胶质细胞参与了下肢骨折伤害性刺激的应激反应及调节过程，而且Fos—LI、PKC-LI的表达早于神经元，可能主动地影响神经元的活动。     

大鼠烫伤后早期肝细胞变化的超微结构观察及形态计量分析

用超微结构形态计量方法分析了大鼠30％烫伤后早期肝细胞超微结构的变化规律。烫伤后,肝细胞内精原迅速减少,至6小时,几乎全部消失。烫伤后2小时、6小时。肝细胞内溶酶体的体积密度、数目密度和平均体积均明显增大。线粒体于烫伤后半小时出现基质密度增加、嵴扩张,烫伤后2小时、6小时,线粒体肿胀,其体积密度、平均体积增大。实验结果提示:在严重烧伤后数小时内,肝细胞的超微结构即出现明显的改变。本文对出现这些变化的机制进行了讨论。     

Thyrotropin-releasing hormone (TRH) counteracts neuronal damage induced by a substance P antagonist

Summary Intrathecal administration of the substance P antagonist Spantide caused marked necrotic changes of the gray matter of the spinal cord extending several segments from the injection site. Intravenous treatment with several doses of thyrotropin releasing hormone before and after Spantide injection completely prevented the necrotic lesion.     

Phasically firing neurons in the supraoptic nucleus of the rat hypothalamus: immunocytochemical and electrophysiological studies

Relations between firing patterns and peptides in supraoptic neurons of rat hypothalamic slice preparations were studied by electrophysiology, intracellular fluorescent dye-marking and immunocytochemistry. Seven out of 10 magnocellular neurons which showed phasically firing patterns were identified by injections of Lucifer Yellow-CH (LY); these were also stained with an anti-vasopressin serum. This report presents direct evidence that most of the phasically firing neurosecretory neurons in the supraoptic nucleus contain vasopressin. This study demonstrates the feasibility of combining immunocytochemical and electrophysiological techniques to study the peptides contents of single mammalian neurons.     

The laminar organization of dorsal horn cells responding to peripheral C fibre stimulation

Summary Cat dorsal horn was searched for all detectable units that responded to peripheral C fibre input. Fifty-seven such units were examined in detail. They were located in two main areas. One group was in the superficial laminae 1, 2, and possibly dorsal 3 (n = 29), and the other group was much deeper in laminae 5 and 6 (n = 24). Only four units were situated in the region of lamina 4.Differences were found in the responses to C fibre stimulation of these two groups, both in the optimum stimulus and in the timing of responses to repeated stimulation. Superficial units often did not respond to C fibre stimulation unless a train of two or more stimuli (10 ms apart) were applied, but when responses did occur they were usually very even and regular, with precise onset latencies on repeated stimulation. Deep units tended to need only one peripheral C fibre stimulus for excitation, but the responses were irregular with latencies fluctuating with each stimulus. Some superficial and deep units showed a steady increase in latency of the late C response on repeated stimulation. Increases of up to 80 ms after 30 s of stimulation at 1 Hz were observed.The results are discussed in terms of the neuronal connections in the dorsal horn.The work was supported by the Medical Research Council and the National Institutes of HealthM. Fitzgerald is a Medical Research Council Training Fellow     

臂丛根性撕脱伤后神经根回植术的大鼠动物模型

目的：建立合理的臂丛根性撕脱伤后神经根回植术的大鼠动物模型。方法：在手术显微镜下，采用前入路，将C6神经根从脊髓上撕脱，咬除同侧C5椎体下外部分，显露脊髓；切断肌皮神经，切取长约30mm尺神经桥接肌皮神经与脊髓间的缺损，并将神经近端植入脊髓。术后观察手术侧前后肢的一般情况；6个月后，观察神经的解剖与组织学的连续性。结果：大鼠存活良好，手术侧前肢无坏死、溃疡、脱落，后肢无瘫痪；从脊髓到肱二头肌，神经的连续性完整；组织学检查见桥接神经段内有神经纤维再生。结论：该模型显露脊髓和切取桥接用神经方便，再植位置准确，便于直接观察神经根再植后神经再生及功能恢复情况，无明显的脊髓损伤并发症，较好模拟了臂丛根性撕脱伤后神经前根的回植。