大鼠脊髓背角浅层中γ-氨基丁酸能神经末梢与含NMDA样 受体或蛋白激酶C样受体神经元之间突触联系的电镜研究

本研究利用受体自显影方法探讨了孤啡肽 (nociceptin/orphaninFQ)在外周炎症和痛觉过敏中的调制作用。将完全弗氏佐剂 (CFA)注射到大鼠一侧后脚掌 2d、4d或 8d后 ,分别进行脊髓C4[3H]孤啡肽结合物的定量测定。放射自显影光密度测定分析表明 ,注射CFA 4d后的动物与对照组相比 ,两侧脊髓Ⅰ -Ⅱ层的中间和外侧区均有 [3H]孤啡肽结合物的明显增加 ;而X层中放射性结合物没有任何改变。生化研究证实 ,[3H]孤啡肽与大鼠脑片的特异性结合 [3H]孤啡肽受体的结合特征是一致的。以上结果提示 ,脊髓 [3H]孤啡肽受体在痛觉过敏期间发生了上调 ;该反应可能通过增强内源性镇痛机制以减弱CFA引起的痛觉过敏。     

Proterties of large-conductance calciumactivated potassium channel in pyramidal neurons acutely isolated from hippocampal CA1 region of adult rat

<正> Properties of large-conductance Ca~(2+) -achvated K~+ (BK_(Ca)channel were studied in ex-cised patches of pyramidal neurons from adult rat hippocampal CAl region using inside-out single channel recording technique. Activity of BK_(Ca)channel was first oborved at[Ca] = l0~(-8)M with the membrane potential of + 20 mV, and the [Ca]_i at which the channel was half activated(P_0 = 0.5)was 2 x 10~(-6)M. Conductance of single BK_(Ca) channel was approx.245 pS with symmetrical 140 mM-K~+ on bo sides of the excisedmembrane,essentially independent of membrane potentials and [Ca]_i, tested. Two exponentials, with the time constants of 2.07 ma and 14.36ms at membrane potential of + 40 mV with 5×10~(-7) M-[Ca]_i,were requied to describe the observed open distrbution of BK_(Ca) channel, sug-gesting existence of two different open channel stathes with apparently normal conductance. BK_(Ca)channel occasionally entered an apparent thirdopen channel state with a single channel current amplitude about 45% the amplitude o     

Auguementations in activity of calcium-activated large conductance potassium channel in pyramidal neurons acutely isolated from adult rat hippocampal CAI region after transient forebrain ischemia

<正> Recent studies have demonstrated that many electrophysiological characteristics of phramidal neurons in hippocanmpalCAl region are changed after transient forebrain ischemia.Large conductance calcium-adtivated potassium(BK_(Ca))channel plays critical roles insetting neuronal electrophysiological properties.Here we examined whether activity of BK_(Ca) channel in CA1 pyramidal neurons of adult rat hip-pocampus changed after transient forebrain ischemia using inside-out configuration of patch clamp techocniques.The results were as follows:(a)Alternation in sensitvity to [Ca~(2+)],was found when the [Ca~(2+)]_i.required to half activate(P_0=0.5)BK_(Ca) channel increased from 2×10~(-6)M to1×10~(-6)M and voltage dependence of BK_(Ca)channel showed no obvious change after ischewia;(b)The unitary conductance of BK_(Ca) channel in-creased by about 20% (from 245 pS to 295 pS in symmetrical 14O/140mM K~+ in inside-out patch)after ischemia;(c)Mean open time of BK_(Ca)channel increased from 12.20 ms to 17.32ms,and     

阿片μ受体在猫脊髓内的分布

应用免疫组织化学方法观察了阿片μ受体在猫脊髓和脊神经节内的分布。在脊髓内，ＭＯＲ样免疫反应产物主要分布于神经毯内，偶尔可见阳性胞体。致密的ＭＯＲ样免疫反应产物主要分布于背角的Ⅰ，Ⅱ层。在胸腰髓和骶髓的中间带外侧核，中央管周围灰质，骶髓节段的后连合核和Ｏｎｕｆ核内发现有中等密度的ＭＯＲ样免疫反应产物。     

猫脊髓后角浅层内GABA能神经终末与表达阿片μ受体神经元之 …

为了研究ＧＡＢＡ与ＭＯＲ在吗啡镇痛中的相互关系，用包埋前免疫组织化学方法结合包埋后胶体金电镜技术，观察了猫脊髓后角浅层内γ－氨基本酸能轴突终末与表达阿片β受体神经元之间的突触联系，结果表明，后角浅层内在三分之一的ＭＯＲ阳性树突和胞体与ＧＡＢＡ阳性终末形成突触连接，这些突触均为对照性突触。     

大鼠福尔马林实验中脊髓后角浅层内P物质和降钙素基因相关？…

为研究尔福马尔林实验动物反应与脊髓内Ｐ物质和降钙素基因相关肽之间可能的相关肽之间可能的相互关系，应用免疫组织化学方法结合图像的分析技术，对福尔马林实验大鼠不同里程的脊髓后角浅层内ＳＰ，ＣＧＲＰ的含量进行了半定量分析，并与大量的行为反应分期进行了比较。