5-羟色胺能神经元向三叉神经运动核和感觉核的投射

Projection of serotoninergic neurons to the trigeminal motor nucleus and sensory nucleus

目的 观察 5 -羟色胺 (5 - HT)能神经元向三叉神经运动核 (Vm )和三叉神经脊束核尾侧亚核 (Vc)的投射 .方法 荧光金 (FG )逆行单标或 Fast Blue (FB)和 Diam idinoYellow(DY)逆行双标与免疫荧光组化染色相结合的双重或三重标记技术 .结果 将 FG注入 Vm或 Vc后 ,在中缝核簇和中脑导水管周围灰质内可见 FG逆标并呈 5 - HT样阳性的双重标记神经元 ;将 FB和 DY同时分别注入 Vm和 Vc后 ,在中缝核簇和中脑导水管周围灰质内可见 FB/DY双标并呈 5 -HT样阳性的三重标记神经元 .结论 5 - HT能神经元不仅向三叉神经运动核及三叉神经感觉核投射 ,而且借助其轴突分支向三叉神经运动核及三叉神经感觉核发出分支投射 ,这些分支投射的 5 - HT能神经元可能具有促进运动功能和抑制感觉传递的双重机能 .

AIM To study the projection of serotoninergic neurons to the trigeminal motor nucleus (Vm) and caudal subnucleus of the spinal trigeminal nucleus in the rat. METHODS Fluoro Gold (FG) single retrograde tracing or Fast Blue (FB) and Diamidino Yellow (DY) double retrograde tracing combined with immunofluoresence histochemical staining techniques were used. RESULTS After injecting FG into the Vm or Vc, FG singly labeled neurons with 5 HT like immunoreactivity were observed in the raphe nuclei and midbrain periaqueductal gray. After injecting the FB or DY into the Vm or Vc, respectively, FB/DY doubly labeled neurons with 5 HT like immunoreactivity were also observed in the raphe nuclei and midbrain periaqueductal gray. CONCLUSION Serotininergic neurons project to the trigeminal motor nucleus and sensory nucleus, some of them also send axonal collateral projections to the trigeminal motor nucleus and sensory nucleus. Those serotoninergic neurons might facilitate motor output and suppress sensory information processing at the same time by those collateral projections.