猫背中缝核向三叉神经脊束核尾侧亚核的投射——HRP法研究

THE PROJECTIONS OF THE NUCLEUS RAPHE DORSALIS TO THE SUBNUCLEUS CAUDALIS OF THE TRIGEMINAL NERVE IN THE CAT

向6例猫右侧三叉神经脊束核尾侧亚核注入30%HRP溶液,观察和分析背中缝核内出现的标记细胞状况。发现标记细胞较集中于核的中段及稍偏吻侧部,向吻尾方向逐渐减少,靠近尾端部全无标记。标记细胞主要出现于核的腹侧部及两外侧部腹缘处,核的背侧部及外侧部的背侧部分甚少,两侧无差别。标记细胞形态多样,但腹侧部及外侧部腹缘处以梭形细胞为主,此处标记也最多。除背中缝核外,脑干尾侧中缝核群(大中缝核、苍白中缝核、隐中缝核)也出现少量标记细胞。结合文献分析,作者等推论背中缝核向尾侧亚核的投射可能与大中缝核向脊髓后角的投射意义相同,两者之间显示着既有分工又有联系的体部定位关系,即背中缝核以向三叉神经脊束核投射为主,也发出少量纤维向脊髓后角投射;以大中缝核为主的脑干尾侧中缝核群主要投射向脊髓后角,但也发出少量纤维投射于三叉神经脊束核。

HRP solution was injected into the right subnucleus caudalis of the trigeminal nerve in the cat,and the labeled cells in the nucleus raphe dorsalis of six cases were examined and analyzed.The labeled cells appeared more in the middle portion and its rostral adjacent parts of the nucleus raphe dorsalis,decreased in number rostrally and caudally,and were entirely absont in the caudal end of the nucleus.In the ventral part and the ventral areas of the lateral parts of the nucleus labeled cells were more than in the other areas of the nucleus,no difference was found between the two sides.In the dorsal part and the dorsal regions of the lateral parts of the nucleus only a few labeled cells were seen.The labeled cells varied in forms,but in the ventral part and the ventral regions of the lateral parts they were mainly fusiform in shape.In addition,in nucleus raphe magnus,nucleus raphe pallidus,and nucleus raphe obscurus,small numbers of neurones were labeled as well.As the nucleus raphe magnus takes part in the inhibition of the response to noxious stimuli in the spinal dorsal horn,and as both the nucleus raphe magnus and nucleus raphe dorsalis belong to the more developed raphe nuclei and contain more 5-HT neurones,it seems that there might be somatotopic relations between the nucleus raphe dorsalis which projects mainly to subnucleus caudalis and the nucleus raphe magnus which projects mainly to the spinal dorsal horn.