大鼠三叉神经脊束核吻侧亚核背内侧部及邻接的外侧网状结构的传出投射——WGA-HRP顺行追踪研究(中脑核—丘脑投射通路研究之二)

在已探明三叉神经中脑核神经元中枢突向三叉神经脊束核吻侧亚核的背内侧部(Vodm)及邻接的网状结构(LRF)投射的基础上,本文作者用WGA—HRP顺行标记法追踪了Vodm和其邻接的LRF传出投射的终止部位,以期探索Vme—丘脑通路中第三级神经元的所在。结果发现Vodm及邻接的LRF除投射到一些脑神经运动核、臂旁核、下橄榄主核腹肢内端外,还发现了前人未曾注意到的沿三叉神经感觉主核内缘存在且向腹侧伸延的一个带状区内有浓密的标记终末终止。此标记终末带区在上橄榄核背侧,三叉神经运动核腹侧以及三叉神经感觉主核的背内侧部等处增大,而上橄榄核背侧及三叉运动核腹侧的终末区以往并无人注意到在此有与之相应的核团。

THE PROJECTION PATHWAY FROM THE TRIGEMINAL MESENCEPHALIC NUCLEUS (Vme)TO THE THALAMUS IN THE RAT. Ⅱ. THE EFFERENT PROJECTION OF THE DORSO-MEDIAL PORTION OF THE SUBNUCLEUS ORALIS OF THE TRIGEMINAL SPINAL NUCLEUS(Vodm) AND THE ADJACENT LATERAL RETI

The present paper is the second part of the serial study on tile projection pathway from trigeminal mesencephalic nucleus(Vme)to the thalamus in the rat. In the experiment 81 rats were used and WGA-HRP were injected into the subnucleus oralis of the trigeminal spinal nucleus (Vodm)and the adjacent lateral reticular formation (LRF)where the "central" processes of the Vme neurens were mainly terminated in order to trace anterogradely the efferent projection from them. It was particularly noted that these projection fibers terminated densely in the zone-shaped area along the medial border of the trigeminal principal sensory nucleus(Vp). The labeled terminating zone was enlarged at the area dorsal to the superior olivary nucleus, the area ventral to the trigeminal motor nucleus, and the medial part of the dorso-medial, portion of Vp.Whether the neurons in the zone-shaped area project to the thalamus or not is yet to be determined further