大鼠孤束核内含calbindin D-28K的内脏伤害性神经元向终纹床核的投射—荧光金标记结合免疫荧光技术研究

既往的研究证明孤束核和终纹床核参与内脏伤害性信息的传递和调控。Calbindin D-2 8K是钙结合蛋白家族的成员 ,为神经细胞特别是投射神经元的选择性标记物。应用荧光金逆行追踪和免疫荧光技术相结合的方法 ,对给予内脏伤害性刺激后大鼠孤束核内 FOS的表达并显示 Calbindin D-2 8K免疫阳性的神经元向终纹床核的投射进行了研究。结果显示 :将荧光金注入一侧终纹床核外侧部后 ,孤束核中尾段内双侧出现荧光金逆行标记细胞 ,注射区同侧占优势 :孤束核的相同平面可观察到双侧等量分布的免疫反应阳性的 Calbindin D-2 8K和 FOS细胞 :三种阳性细胞的分布有明显的重叠现象。在其重叠分布区可见荧光金 /Calbindin D-2 8K、FOS/Calbindin D-2 8K、荧光金 /FOS双重阳性以及荧光金 /Calbindin D-2 8K/FOS三重阳性细胞。除 FOS/Cal-bindin D-2 8K双重阳性细胞为双侧分布外 ,荧光金 /Calbindin D-2 8K、荧光金 /FOS双重阳性以及荧光金 /Calbindin D-2 8K/F OS三重阳性细胞的出现均以注射区同侧为主。荧光金 /Calbindin D-2 8K、F OS/Calbindin D-2 8K双重阳性和荧光金 /Calbindin D-2 8K/F OS三重阳性神经元占孤束核内 Calbindin D-2 8K免疫阳性神经元总数的百分比分别为 2 .79%、15 .3 %和 2 .5 6% ;荧光金/Calbindin

PROJECTIONS OF THE VISCERAL NOCICEPTIVE NEURONS CONTAINING CALBINDIN D-28K FROM THE NUCLEUS TRACTUS SOLITARII TO THE BED NUCLEUS OF THE STRIA TERMINALIS IN THE RAT

It has been reported that the nucleus tractus solitarii(NTS) and the bed nucleus of the stria terminalis (BST) are involved in conducting and modulating visceral nociceptive information. Calbindin D 28K(CB), a member of calcium binding protein family, often serves as a selective marker for nerve cells, especially for projection neurons. Using the method of fluoro gold (FG) retrograde tracing combined with immunofluorescence histochemistry, the projection to BST from the calbindin D 28K immunoreactive neurons in the NTS which expressed immunoreactivity for FOS protein after nociceptive visceral stimulation was investigated in the present study. After injecting FG into the lateral BST, the FG retrogradely labeled neurons were found in the mid caudal part of NTS bilaterally with ipsilateral side predominance. CB and FOS immunoreactive neurons were distributed equally in both sides of NTS. The three types of labeled neurons(FG, CB and FOS)overlapped in the same part of NTS. FG/CB, FG/FOS, FOS/CB double labeled neurons, and FG/CB/FOS triple labeled neurons were found in the overlapping region. Except that the FOS/CB double labeled neurons were distributed bilaterally, the rest of double labeled and triple labeled neurons were found in the ipsilateral injection side predominantly. The proportion of FG/CB, FOS/CB double labeled neurons and FG/CB/FOS triple labeled neurons in NTS was 2.79%, 15.3% and 2.56% to total number of the CB immunoreactive neurons, respectively. The proportion of FG/CB/FOS triple labeled neurons in NTS was 47.8% to total number of the FG/CB double labeled neurons. The results of the present study suggest that CB might be involved in the transmission of visceral nociceptive information from NTS to BST.