大鼠中脑中央灰质和中缝背核向伏核和三叉神经脊束核尾侧亚核的分支投射——荧光素双标记法研究

THE COLLATERAL PROJECTIONS FROM THE MIDBRAIN PERIAQUEDUCTAL GRAY AND NUCLEUS RAPHE DORSALIS TO THE CAUDAL PART OF THE SPINAL TRIGEMINAL NUCLEUS AND NUCLEUS ACCUMBENS IN THE RAT

将碘化丙啶(PI)和双苯甲胺(Bb)分别注入同侧的伏核和三叉神经脊束核尾侧亚核,在中脑中央灰质和中缝背核内见到双标和2种单标神经元。双标神经元占3种标记神经元总数的9％,PI单标神经元占58％,Bb单标神经元占33％。双标神经元多位于中脑中央灰质中、尾段的腹外侧区、内侧区腹侧部和中缝背核内;PI单标神经元的分布同双标神经元;Bb单标神经元除位于上述区域外,还可见于背外侧区和背侧区。位于注射区同侧的标记神经元多于对侧,标记神经元以中型梭形和三角形为主。

The fluorescein double-labeled method was used in the present study to investigate the collateral projections from the rat midbrain periaqueductal gray (PAG) and nucleus raphe dorsalis (DR) to the caudal part of the spinal trigeminal nucleus (Sp5C) and nucleus accumbens (ACB) by injecting propidium iodide (PI) into ACB and bisbenzimide (Bb) into Sp5C at different times on the same side, respectively. Double-labeled neurons and 2 kinds of single-labeled neurons could be observed in PAG and DR. The percentages of double-labeled neurons were 9%; PI single-labeled neurons were 58%; Bb single-labeled neurons were 33%. Double-labeled neurons were located in the ventrolateral and ventral part of medial subdivisions at rostral, middle and caudal levels of PAG and in the rostrocaudal extents of DR; the distributions of PI single-labeled neurons were the same as double-labeled neurons; while Bb singlelabeled neurons were also seen in the dorsal and dorsolateral subdivisions besides the area mentioned above in PAG and DR. The labeled neurons on the ipsilateral side to the fluorescein injection were more than that on the controlateral side. Most of the labeled neurons were medium in size (20-30 μm) and fusiform or triangular in shape.