吗啡对备用根大鼠背根节神经元胞体的影响──光镜和电镜观察

EFFECTS OF MORPHINE ON THE NEURONAL SOMA IN DORSAL ROOT GANGLION OF SPARED ROOT RAT ──LIGHT AND ELECTRON MICROSCOPIC OBSERVATIONS

用光镜体视学方法，结合电镜观察，探讨发生侧支出芽和重建突触的背根节神经元，其胞体是否也呈现相应的形态变化，以及吗啡对这些变化的影响。吗啡备用根组和备用根对照组的大鼠术侧背根节体积与非术侧比较，均没有明显的统计学差异；其亮神经元胞体、胞核和核仁的体积也没有显著性差异。对照组非术侧亮神经元胞体的尼氏体呈颗粒状，多聚核糖体聚集成小簇，分散在胞质中。术侧尼氏体则呈小块状，多聚核糖体簇较大，较为密集。吗啡组术侧亮神经元胞体的尼氏体也在胞核周围聚集成小块状，有些还呈斑块样。此时可见多聚核糖体呈团簇状，其分布更为密集。这种变化可能与发出有髓传入纤维的亮神经元在脊髓内侧支出芽及重建突触有关。对照组术侧暗神经元胞体、胞核和核仁的体积，比非术侧显著增大。吗啡组术侧暗神经元胞体、胞核和核仁的体积又比对照组术侧的大，而且胞质的多聚核糖体和粗面内质网明显增多，表明与无髓传入纤维在脊髓侧支出芽及重建突触有关的暗神经元胞体也发生了相应的形态变化，吗啡对这些变化有明显的促进作用。

Morphological changes of the neuronal soma of dorsal root ganglion(DRG)which undergone collateral sprouting and synaptic reconstruction were explored with LM stereological method and EM observation.The effects of morphine on the morphological changes were also observed.There was no significant difference in the volume of DRG on operated side of morphine group and control group compared with the unoperated side,There were also no obvious changes in the volume of somata,nuclei and nucleoli of large pale neurons,In unoperated side of control group,Nissl bodies of large pale neurons appeared as fine particles,Polyribosome were arranged in variable sizeed aggregations in the cytoplasm;In operated side,Nissl bodies appeared as small clumps in large pale neurons. Polyribosome aggregation were larger.In operated side of morphine group.Nissl bodies of large pale neurons appeared also as small clumps around the nucleus;some were scattered as mass-like.Large polyribosome aggregation were observated and distributed more densely,The alteration may be related to the collateral sprouting and synaptic reconstruction of large pale neurons in spinal cord,which give rise to the myelinated afferent fibers.The volume of somata,nuclei and nucleoli of small dense neurons in operated side of control group achieved higher values than in unoperated side,In operated side of morphine group,not only above-mentioned volume of small dense neurons was significantly larger than that of control group,but also polyribosome and rough endoplasmic reticulum in the cytoplasm increased evidently. The results suggest that the soma of small dense neurons which are related to the collateral sprouting and synaptic reconstruction of unmyelinated afferent fibers in spinal cord shows relevant morphological changes and morphine may promote this alteration.