Direct excitatory effects of neuropeptide Y (NPY) on rat hippocampal neurones in vitro

Intracellular recordings from granule cells of the rat dentate gyrus show neuropeptide Y (NPY) applied by pressure ejection from pipettes containing 1.2-12 microM by pressures of less than 200 kPa for 1-5 s in duration to consistently evoke membrane depolarisations accompanied by a reduction in membrane resistance. The depolarisations were accompanied by an increase in excitability. Since the depolarisations evoked by NPY were not attenuated by either tetrodotoxin or kynurenic acid a direct excitatory action of NPY is postulated.     

Synaptic reorganization in the medial amygdaloid nucleus after lesion of the accessory olfactory bulb of adult rat. II. New synapse formation in the medial amygdaloid nucleus by fibers from the bed nucleus of the stria terminalis

The rearrangement of terminations from the bed nucleus of stria terminalis (BST) was examined in the medial amygdaloid nucleus (MAN) at 2 months following the lesion of the accessory olfactory bulb (AOB) using an electron microscopy and degeneration study. At 2 days following a BST lesion, the number of degenerating synapses was 0.7 ± 0.1 (mean±S.E.M.) per unit area (2500 μm² in the molecular layer, and 3/0 ± 0.3 in the cellular part. At 2 months after an AOB lesion, the degenerating synapses from the AOB had completely disappeared from the MAN. The BST was then lesioned at 2 months after the AOB lesion and, 2 days following this BST lesion, the degenerating synapses were counted in MAN. The numbers observed were 3.3 ± 0.6 per unit area in the molecular layer and 4.5 ± 0.4 in the cellular part. Therefore, the number of these degenerating synapses increased significantly within the molecular layer, though, in the cellular part the number of synapses was not significantly elevated over control. No differences in postsynaptic profiles (ratio of synapses on dendritic spine to dendritic shaft) were observed after the AOB lesion. These results indicate that the BST fibers formed new synapses in the molecular layer following the denervation of AOB fibers. The possibility of new synapse formation by other afferent fibers in addition to the AOB fibers is discussed as is the relationship between lesion induced synaptic reorganization and functional recovery after injury.     

Effects of ageing on the total number of muscle fibers and motoneurons of the tibialis anterior and soleus muscles in the rat

The age-related changes in the total number of muscle fibers and motoneurons of the tibialis anterior and soleus muscles were studied using 10-, 65-, and 135-week-old rats. The number of fast twitch muscle fibers was decreased at age 65 weeks, while the numbers of slow twitch fibers and of alpha motoneurons were decreased only later, at age 135 weeks. Therefore, the degenerative process of muscle fibers differs with the fiber type.     

Effects of stimulation and blockade of dopamine receptor subtypes on the discriminative stimulus properties of cocaine

The involvement of dopamine (DA) receptor subtypes in the behavioral effects of CNS stimulants was studied in rats trained to discriminate occaine from saline. In substitution tests, the stimulus effects of 10mg/kg of this substance generalized tod-amphetamine (0.25–1.0 mg/kg) and the selective D₂ against LY-171555 (0.05–0.25 mg/kg); but not to the D₁ agonist SKF-38393 (5.0–15.0 mg/kg); in combination tests, the D₁ antagonist Sch-23390 (0.0625–0.5 mg/kg) significantly blocked, and the D₂ antagonist spiperone (0.25–0.5 mg/kg) partially blocked the cocaine cue. These data suggest that the involvement of DA systems in the behavioral effects of cocaine is more complex than either D₁ or D₂ receptor activation; for example, the stimulus properties of this substance might involve both D₁ and D₂ receptor activation.Some of these results were presented at the meeting of the Society for Neuroscience, Toronto, 1988     

实验性肌炎动物模型制作的研究

目的建立实验性肌炎动物模型，研究特发性炎性肌病的发病机制。方法将50只健康的雄性SD大鼠随机分成两组：模型组40只，对照组10只。兔骨骼肌制备肌匀浆。模型组用肌匀浆与弗氏完全佐剂完全乳化后皮下免疫注射1ml．对照组用生理盐水替代肌匀浆，每周免疫1次，连续免疫5次。前2周同时腹腔注射百日咳毒素1ml。分别于免疫注射后各周取大鼠的骨骼肌组织，观察其肌活检病理、免疫组织化学的改变，同时检测血清肌酶水平，并与人类炎性肌病比较。结果模型组肌酶升高与对照组间有显著差别。病理改变以骨骼肌多发性炎症为特点：横纹肌呈灶性分布的肌纤维变性、坏死，横纹消失；周围炎性细胞浸润；肌纤维粗细不等、染色不一。病理分级以2a级为主。单个核细胞浸润以CD8^＋T细胞为主．主要定位于肌内膜。骨骼肌细胞膜上主要组织相容性复合体（MHC）-Ⅰ类分子表达增加。结论用异种动物骨骼肌匀浆免疫大鼠可诱导出炎性肌病动物模型，与人类炎性肌病在临床表现、组织病理和免疫组织化学方面有相似之处。     

大鼠骨髓间充质干细胞与多孔双相磷酸钙陶瓷支架体外黏附的实验研究

目的研究大鼠骨髓间充质干细胞(marrowmesenchymalstemcells,MSCs)诱导培养后在多孔双相磷酸钙(biphasiccalciumphosphate,BCP)陶瓷支架材料上的黏附和生长。方法SD大鼠MSCs经矿化诱导培养、扩增,具有成骨细胞表型后,与多孔BCP陶瓷支架及普通多孔羟基磷灰石(hydroxyapatite,HA)陶瓷支架体外复合培养,扫描电镜观察比较MSCs在两种材料支架表面的黏附数量和形态;同时以0.5、1.0、2.0、3.0和4.0×106/ml浓度细胞悬液接种于多孔BCP支架材料,检测适宜的接种浓度及单位体积支架材料可黏附MSCs数量。结果大鼠MSCs经诱导培养14d后,行矿化沉积茜素红染色、型胶原免疫细胞化学染色及碱性磷酸酶细胞化学染色,结果均为阳性。大鼠MSCs黏附于多孔BCP陶瓷上的细胞数(88.00±6.58)明显高于HA陶瓷组(39.00±3.65),两组比较差异有统计学意义(P<0.01)。当接种浓度为2.0×106/ml时,单位体积的陶瓷支架材料最多可黏附MSCs数量为1.28×107个/cm3,为细胞适宜接种浓度。结论大鼠MSCs在体外经矿化诱导培养可表达成骨细胞表型,细胞浓度为2.0×106/ml时与多孔BCP陶瓷支架材料具有良好的黏附能力。     

低剂量他克莫司治疗大鼠急性脊髓损伤的实验研究

目的：探讨低剂量他克莫司（tacrolimus，又名FK506）对大鼠急性脊髓损伤是否具有神经保护作用。方法：雄性Wistar大鼠72只，随机分为假手术组（12只）、损伤组（30只）和FK506治疗组（30只）。采用Allen’s打击法致伤大鼠T10脊髓，假手术组仅做椎板切除术。FK506治疗组在脊髓损伤后5min一次性经尾静脉注射FK5060．3mg／kg，其余两组以相同方法给予等量生理盐水。致伤后30min、6h、24h、48h、72h取伤段脊髓组织行病理观察及原位末端标记法（TUNEL）检测神经细胞凋亡，伤后1、3、7、14、21d行脊髓功能BBB评分和斜板实验。结果：伤后3、7、14、21d，FK506治疗组斜板实验和BBB评分明显优于损伤组，两组间比较差异有显著性（P〈0．05）；伤后各时间点FK506治疗组脊髓损伤区出血坏死较损伤组轻；伤后6、24、48、72h神经细胞凋亡FK506治疗组较损伤组明显减少，两组间比较差异有显著性（P〈0．05）。结论：在大鼠急性脊髓损伤后早期应用低剂量他克莫司（0．3mg/kg）治疗对神经具有保护作用，可减少神经细胞凋亡，减轻脊髓继发性损伤，促进脊髓功能恢复。     

碘和甲状腺球蛋白诱导大鼠自身免疫性甲状腺炎的研究

目的　研究碘与自身免疫性甲状腺炎 (EAT)的关系。方法　用碘和甲状腺球蛋白 (TG)诱导SD大鼠建立甲状腺炎模型 ,随机分为 5组 ,每组 10只。正常对照组 (NC组 ) ;少量碘组 (LI组 ) :饮 5 0 0 μg/L碘化钠水 ;大量碘组 (HI组 ) :饮 5 0 0mg/L碘化钠水 ;TG组 :于实验第 15天大鼠接受皮内多点注射完全福氏佐剂乳化的TG各 10 0 μg作为初次免疫 ,2周后以不完全福氏佐剂乳化的TG加强免疫 ,以后每周加强免疫 1次至第 6周末实验结束 ;TG HI组 :TG及HI给药方法同上。至第 6周末实验结束处死所有动物 ,用放免法检测血清TG抗体 (TGAb)及甲状腺过氧化物酶抗体 (TPOAb)效价 ,并于光镜下观察甲状腺组织淋巴细胞浸润程度。结果　TG HI组、HI组及TG组甲状腺滤泡破坏及淋巴细胞浸润均较明显 ,TG HI组及HI组与NC组比较 ,P<0 .0 5 ,TG组与NC组比较有增高趋势 ,但无统计学意义。 3组TGAb、TPOAb均明显高于NC组及LI组 (P<0 .0 1;仅HI组TPOAbP<0 .0 5 )。各组TGAb及TPOAb水平与甲状腺病理分级呈正相关关系 (r =0 .9,P<0 .0 5 )。结论　高碘可诱发SD鼠EAT发生 ,TG与高碘结合诱导SD大鼠EAT的作用更明显     

小鼠卵子不同获取时间和处理对体外受精率和受孕率的影响

为了解急性胰腺炎急性期局部组织结构所起的作用,采用牛磺胆酸钠逆行胰胆管注射制备大鼠胆源性急性胰腺炎的模型。并观察了模型制备后原发性病变与继发性局部病变以及胰腺病理的变化。大体病理所见:同一时段的模型各组间比较差异均非常显著(P<0.01)。胰腺水肿或出血坏死和胰周水肿或出血坏死间均存在正相关(P<0.01)。镜下病理所见:同一时段的模型中,除了6h间质出血和脂肪坏死各组间差异显著外(P<0.05),其余均差异非常显著(P<0.01)。例外情况的病理所见:2例轻度胰腺水肿或出血与腹膜后间隙广泛浸润:3例重度胰腺水肿或出血坏死与腹膜后局限浸润:5例出血坏死组脾门区病变严重。结果提示,在实验模型制备条件近似相同的情况下,原发性病变越严重,继发性的局部病变也越严重。局部病变表现的差异,可能与局部组织结构上存在的差异有关。     

外消旋聚乳酸复合神经生长因子缓释导管促周围神经再生的形态学研究

目的 建立外消旋聚乳酸复合神经生长因子（poly-D，L-lactic acid／nerve growth factor，PDLLA／NGF）可吸收性缓释导管桥接修复大鼠坐骨神经缺损的动物模型，观察复合导管对大鼠坐骨神经缺损再生的促进作用。方法利用溶剂挥发法制备PDLLA单纯导管和PDLLA／NGF缓释导管，每根缓释导管含NGF450U。SD大鼠40只随机分成4组，每组10只，切除中段坐骨神经10mm之后分别行自体神经移植（A组）、单纯导管桥接（B组）、单纯导管加一次性给药（C组）、PDLLA／NGF缓释导管桥接（D组）修复坐骨神经，除A组外，均保留10mm缺损。术后3个月观察神经再生情况，比较各组光镜、电镜及图像分析等指标。结果术后3个月导管与周围组织粘连松，并开始降解，但外形仍保持完整。再生神经均顺利通过导管腔，组织学观察A组和D组内神经纤维数目多，大小均匀，成熟良好；B组和C组纤维结缔组织多，神经纤维细小，髓鞘薄。图像分析显示除神经纤维计数D组高于A组外，A组和D组在纤维直径、轴突直径和髓鞘厚度方面差异均无统计学意义（P〉0．05），并明显优于B组和C组（P〈0．05）。结论 PDLLA／NGF缓释导管能够有效促进大鼠坐骨神经缺损再生，组织学观察指标接近自体神经移植。