外周伤害性刺激诱导大鼠脑干内延髓网状背侧亚核传入投射神经元的c-fos表达

PERIPHERAL NOXIOUS STIMULATION-INDUCED EXPRESSION OF FOS PROTEIN IN NEURONES OF BRAIN STEM PROJECTING TO THE MEDULLARY SUBNUCLEUS RETICULARIS DORSALIS IN THE RAT

用荧光金逆行追踪和 FOS荧光免疫组织化学染色相结合的方法对外周伤害性刺激下大鼠脑干内向延髓网状背侧亚核传入投射的神经元中 c- fos的表达进行了研究。在麻醉状况下将 0 .15 μl2 %荧光金注入大鼠单侧延髓网状背侧亚核 ,存活5 d后用 1%福尔马林刺激同侧前爪、后爪和口周 ,2 h后灌注取材 ,再行 FOS免疫荧光标记。结果发现在脑的中脑导水管周围灰质、中缝背核、线形核和中缝大核内观察到荧光金标记细胞、FOS样免疫阳性反应细胞及荧光金 / FOS双标细胞。在这四个核团中 ,双标细胞数分别占荧光金逆标神经元数的 2 5 % (中脑导水管周围灰质 )、 11.7% (中缝背核 )、 8.9% (线形核 )和 12 .1% (中缝大核 )。结果提示在脑干向延髓网状背侧亚核投射的神经元中 ,有一部分与外周伤害性刺激信息的调控有关 ,还有的神经元可能具有其它的功能。

The method combined fluorogold(FG) retrograde with fluorescent immunohistochemistry was used to study c fos expression of the neurons of brian stem projecting to the subnucleus reticularis dorsalis(SRD) under noxious stimulation. The rats were anaesthetized and injected unileterally with 0 15 μl of 2% FG into SRD. After five days survival period, noxious peripheral stimulation was given by injecting 1% formalin subcutaneous into the ipsilateral hindpaw, forepaw and muzzle of the rats. Two hours later, the rats were perfused and the brain was removed and sectioned. The sections were processed for FOS fluorescent immunohistochemistry. The results showed: FG retrogradely labelled cells, FOS like immunoreaction(FOS L1) single labelled cells and FG/FOS double labelled neurones were found in the periaqueductal gray (PAG), dorsal raphe nucleus(DRN), linear nucleus raphe(LR) and nucleus raphe magnus(NRM). The percentage of double labelled cells in the population of retrogradely labelled cells was 25% in PAG, 11 7% in DRN, 8 9% in LR, 12 1% in NRM, respectively results suggest that some afferent neurons to SRD in brain stem are involved in modulation of peripheral noxious signals, the other neurons may have other functions \;