摘要
本实验通过Pos免疫细胞化学、电生理及微量注射法对中缝隐核(NRO)的交感抑制作用的相关途径进行探讨。实验在成巴比妥钠或α-氯醛糖和氨基甲酸乙脂麻醉的Sprague-Dawley(SD)大鼠上进行。同时予以NRO,中脑导水管周围灰质背侧部(dPAG)方波脉冲串刺激,诱导中脑和延髓的c-Fos表达。刺激NRO过程中,基础血压升高(P<0.05),刺激dPAG引起的防御性升压反应则减少(P<0.01);中脑导水管周围灰质腹侧部(vPAG)、巨细胞旁外侧核(PGL)的Fos样免疫阳性反应(FLI)细胞计数分别为66.5±8.3和10.8±1.5(刺激NRO+dPAG组),较单独刺激dPAG组明显增加,P值分别小于0.01和0.001;单或双脉冲刺激中缝隐核在vPAG可以记录到相关单位,其中84%为兴奋单位,抑制单位占16%。双侧vPAG内微量注射利多卡因(每侧2μg/0.1μl),基础血压无明显变化,而刺激NRO引起的降压反应幅度减小(P<0.01),提示,延髓腹外侧区(VLM)、NRO存在不同功能分化的神经元;NRO可能有向vPAG的兴奋性投射,此投射可加强NRO的交感抑制效应。
Experiments were carried out on rats anaesthetized with sodium Pentobarbital or urethane and alpha-chloralose. Nucleus raphe obscurus (NRO) and dorsal periaqueductal grey (dPAG) were stimulated singly or simultaneously by square-wave pulses to induce the Fos-expression in midbrain and medulla oblongata. During the period of NRO stimulation, the hasal blood pressure was increased (P<0.05), the defensive pressor respouse to stimulation of dPAG was attenuated (P<0.01). When both NRO and dPAG were stimulated, Fos-like immunoreactive (FLI) cells in the ventral periaqueductal grey (vPAG) and paragigantocellularis lateralis (PGL) were increased as compared with cases in which the stimulation was only delivered to dPAG, i. e., reaching a FLI cell count value of 66.5±8.3 and 10.8±1.5 respectively. Stimulation of the NRO with single or paired stimulus evoked both excitatory (84% ) and inhibitory (16% ) respouses of the units in vPAG. Bilateral microinjection of lidocaine (2 μg in 0.1 μl/side) into vPAG attenuated the depressor responses induced by stimulation of NRO, but little change in hasal blood pressure (P>0.01). It is suggested that there exist different types of neurons possessing different functions in the ventral lateral medulla (VLM) and NRO and that an excitatory projection from the NRO to vPAG may mediate the sympathoinhibitory effect of the nucleus.
出处
《生理学报》
CAS
CSCD
北大核心
1996年第2期149-156,共8页
Acta Physiologica Sinica
基金
国家自然科学基金
关键词
中缝隐核
中脑导水管
周围灰质
C-FOS
电生理
nucleus raphe obscurus
ventral periaqueductal grey
defensive response
c-Fos
electrophysiology
microinjection