猫三叉神经脊束核尾侧亚核第V层中红核下行纤维终末的超微结构特征——溃变及HRP电镜法

ULTRASTRUCTURE OF THE DESCENDING RUBRAL FIBERS IN LAMINA V OF THE CAT TRIGEMINAL SUBNUCLEUS CAUDALIS——HRP LABELING AND DEGENERATION STUDY

本文报道用电解法或注入海人酸毁损红核吻侧2/3部,另外,再将WGA-HRP溶液注入该部,在电镜下观察投射到对侧三叉神经脊束核尾侧亚核第Ⅴ层中的溃变终末和HRP标记终末的形态特征。发现溃变和HRP标记终末多含圆形或混合型小泡,大多数终末与中、小型树突形成对称型突触,从而推测红核下行纤维可能对第Ⅴ层神经元起抑制性调节作用,可影响面、口部躯体感觉的传入。本文提示红核不仅参与躯体不随意运动的调控,可能对面、口部感觉传递也起整合作用。另外,本文对溃变电镜和HRP(TMB反应)标记电镜的技术方法进行了讨论。

After a injection of kainic acid or WGA-HRP into the red nucleus, the degenerated or HRP labeled terminals in lamina V of the contralateral trigeminal subnucleus caudalis (Vc) were examined electron microscopically. It was found that the degenerated and HRP labeled terminals contained vesicles of spherical or mixed type, and formed symmetrical synapses with medium- or small-sized dendrites. These findings suggested that the descending rubral fibers might be inhibitory in regulating the activity of the neurons, and supposed to be sensory in nature. Thus the red nucleus might play certain role in modulation of the oro-facial somatosensory transmission (including pain) in lamina V of Vc, besides the rubrospinal influence on the involuntary motor functions of the spinal anterior horn. The technique for tracing neural connections with electron microscope was discussed as well.