延髓感觉核向丘脑和下丘的投射——荧光素双标记法

本文应用荧光素双标记法研究了后索核、孤束核、三叉神经脊束核向下丘和丘脑投射神经元的分布及其分支投射。作者将Propidium Iodide注入大白鼠右侧丘脑,Bisbenzimide注入右侧下丘,结果如下:楔束核内被标记的神经元中有88.2％向丘脑投射,它们位于核的主部;11.2％向下丘投射,它们在尾侧主要位于核的边缘部,向吻侧(至闩平面)主要位于核的背外侧端。薄束核内被标记的神经元中向下丘投射者(10.9％)与向丘脑投射者(86.7％)混杂在一起。在此两核内仅有极少量分支投射的双标神经元。孤束核和三叉神经脊束核内被标记的神经元中约有2/3投向丘脑,1/3投向下丘,未见分支投射的双标神经元。

PROJECTIONS FROM THE SENSORY NUCLEI OF THE MEDULLA TO THE THALAMUS AND INFERIOR COLLICULUS——A FLUORESCENT DOUBLE-LABELING STUDY

The dorsal column nuclei, spinal trigeminal nucleus and nucleus solitarius project to the thalamus and inferior colliculus. In order to determine whether any of them have collateral projections, the fluorescent double-labeling technique was used. Propidium Iodide was injected to the right thalamus, Bisbenzimide was injected to the right inferior colliculus irt the rat. The results were as follows:Within the cuneate nucleus, aboat 11.2％ of the labeled neurons projected to the inferior colliculus and were mainly located along the edges of the nucleus caudally, and in the dorsolateral part of the nucleus rostrally (to the level of the obex), but the thalamusprojecting neurons were about 88.2％ and were present in the main part of the nucleus. Within the gracile nucleus, the labeled thalamus projecting neurons (about 85.7％) were mixed with the labeled inferior colliculusprojecting neurons (about 10.9％). The neurons projecting to both the thalamus and the inferior colliculus, which presumably were through collaterals and were double-labeled in our experiments, were rarely found in the dorsal column nuclei. Within spinal trigeminal nucleus and nucleus solitarius, about 2/3 labeled neurons projected to the thalamus and about 1/3 labeled neurons projected to the inferior colliculus. The double-labeled neurons were not observed.