大鼠脑桥排尿中枢和脊髓交感中枢之间的形态学研究

为研究大鼠排尿过程中交感神经同副交感神经协同作用的形态学基础,通过形态学方法,用生物素标记的葡聚糖胺(BDA)顺行标记从脑桥排尿中枢(PMC)投射到腰6至骶1(L6~S1)脊髓节段的神经末梢。将荧光金(FG)注入盆节逆行标记副交感神经节前神经元(PPNs),并且通过免疫组化的方法判断该逆标的神经元是否为胆碱能性的。于L1~L2节段IML区和L6~S1节段骶副交感核(SPN)分别注射辣根过氧化物酶(HRP)和麦芽凝集素结合的HRP(WGA-HRP),分别在L6~S1检测逆标神经元和L1~L2节段检测顺行标记终末。结果显示,于L1~L2节段IML区交感节前神经元所在部位注射HRP,在同侧SPN的背内侧发现有逆标神经元,且该神经元为非胆碱能神经元,其胞体显著小于PPNs(P<0.05)。BDA标记的神经末梢主要位于L6~S1节段双侧IML区,也是SPN的所在部位,并发现有些末梢和同侧逆标的HRP阳性神经元有紧密接触。SPN中电泳入WGA-HRP,发现在L1~L2节段IML区有顺标的神经末梢。上述结果提示,脑桥排尿中枢可能通过位于SPN背侧的中间神经元对L1~L2节段IML区内的交感节前神经元发挥调控作用。

MORPHOLOGIC RELATIONSHIP OF THE PONTINE MICTURITION CENTER AND SYMPATHETIC CENTER IN THE SPINAL CORD OF THE RAT

To study whether the sympathetic nerve coordinates with the parasympathetic nerve during micturition in the rat, we labelled the terminals in the L6-S1 spinal cord segment of the rat that involved in bladder control using antegrade transport of biotinylated dextran amine(BDA) from the pontine micturition center(PMC).Preganglionic parasympathetic neurons(PPNs) in the L6-S1 spinal cord were labelled by retrograde transport of Fluorogold(FG) from the major pelvic ganglion.PPNs were identified whether choline acetyltransferase-immunoreactive (ChAT-IR) by immunohistochemical method.Horseradish peroxidase(HRP) and wheat germ agglutinin-HRP(WGA-HRP) was injected into the IML of L1-L2 segment and the sacral parasympathetic nucleus(SPN) to detect the retrograde neurons and antegrade terminals in the SPN and IML, respectively. The results showed that PPNs located in SPN and they were ChAT-IR. There were many HRP-labelled neurons located dorsally to PPNs, and they were not ChAT-IR and smaller than those in PPNs significantly (P<0.05). BDA-labelled terminals were located mainly in the bilateral IML of L6-S1 cord where the SPN located, and some terminals had thick contact with the HRP-labelled neurons. In addition, there were some WGA-HRP labelled terminals in the ipsilateral IML in L1-L2 segment after WGA-HRP being injected into the SPN. The above results suggest that PMC may control the preganglionic neurons of sympathetic nerve through the interneurons that were located dorsally to PPNs.