大鼠孤束核内传递内脏伤害性信息的儿茶酚胺能神经元向臂旁核的投射

应用四甲基罗达明 ( TMR)逆行追踪结合胃肠道福尔马林溶液刺激和免疫荧光技术 ,在激光扫描共聚焦显微镜下对孤束核内向臂旁核投射的表达 FOS的儿茶酚胺能神经元进行了观察。将 TMR注入一侧外侧臂旁核后 ,孤束核尾段的背内侧、胶质、内侧、小细胞、中间内侧等亚核和连合亚核内出现较多的逆标神经元。上述各亚核内可见到 TMR,酪氨酸羟化酶 ( TH)和 F OS阳性神经元重叠分布 ,部分神经元为 TMR/ FOS,TMR/ TH和 FOS/ TH双重阳性及 TMR/ F OS/ TH三重阳性神经元。其中 TH样阳性神经元数量最多 ,TMR/ TH、FOS/ TH双重阳性和 TMR/ FOS/ TH三重阳性神经元数量占 NTS内 TH样阳性神经元总数的百分比分别为 44.2 % ( 6 8/ 15 4)、2 6 .6 % ( 4 1/ 15 4)和 12 .3% ( 19/ 15 4)。本研究结果提示 ,对大鼠胃肠道进行伤害性刺激后孤束核内表达 FOS的儿茶酚胺能神经元向臂旁核投射 ,它可能参与内脏伤害性信息的传递

CATECHOLAMINERGIC NEURONS IN THE NUCLEUS TRACTUS SOLITARII TRANSMITTING VISCERAL NOCICEPTIVE INFORMATION PROJECT TO THE PARABRACHIAL NUCLEUS

Using the method of injecting tetramethyl rhodamine (TMR) into the lateral parabrachial nucleus combined with stimulating stomach with formalin and immunofluorescence histochemistry for FOS and TH, catecholaminergic neurons in the nucleus tractus solitarii transmitting visceral nociceptive information projecting to the parabrachial nucleus were investigated. Under laser scanning confocal microscope, it was shown that 3 kinds of single labeled neurons (TMR, TH, FOS), 3 kinds of double labeled neurons (TMR/FOS, TMR/TH, FOS/TH) and TMR/FOS/TH triple labeled neurons were overlapped in the medial, dorsomedial, intermediate, gelatinous, parvicellular, and commissural subnuclei of the mid caudal part of NTS. The percentage of TMR/TH, FOS/TH and TMR/FOS/TH neurons was 44.2%, 26.6% and 12.3%, respectively, of the total number of TH positive neurons which were the most numerous in NTS. It suggests that CAergic neurons in NTS might be involved in processing and conducting visceral nociceptive information.