【摘要】 清醒箭毒化雄性大白鼠,在人工呼吸维持下,1.分析下丘脑弓状核(AR)兴奋中缝大核(NRM)的机制:观察到电刺激 AR 对 NRM 的兴奋效应,可因切断双侧 AR 至导水管周围灰质(PAG)的β-内啡肽(β-End)能束、PAG 内双侧注射纳洛酮或抗β-End 血清而绝大部分消失,提示 AR 对 NRM 的兴奋效应,主要通过 AR 区β-End 能神经元轴突与 PAG-NRM 系统的直接联系而实现;2.检验 AR 至 PAG-NRM 的神经通路在电针效应中的作用:实验显示上丘水平去大脑后,电针兴奋 NRM 的效应完全消失,表明此效应主要依赖中脑以上结构实现;进一步分别用 Halász 氏刀游离 AR、切断 AR 至 PAG 的β-End 能束、PAG 内注射纳洛酮或抗β-End 血清后,也使电针效应基本上完全消失,说明电针使 NRM神经元兴奋的效应,主要通过 AR 与 PAG-NRM 间的β-End 能神经通路实现。更多还原

【Abstract】 The following results were obtained from conscious curarized rats under artifi-cial respiration.(1)The main excitatory effects of stimulation of nucleus arcua-tus hypothalami(AR)on unit discharge of nucleus raphe magnus(NRM)wereabolished by section of β-endorphinergic tract and by microinjection of naloxoneor anti-β-endorphin serum into periaqueductal gray matter(PAG).This suggeststhat the excitatory effect of AR on NRM might be conducted through a directconnection between the axons of β-endorphinergic AR-neurons and PAG-NRMsystem.(2)The activation of NRM neurons by electroacupuncture(EA)waseliminated after decerebration at superior colliculus level,indicating that thiseffect of EA depends mainly on the supra-midbrain structure.Furthermore,alltreatments including AR isolation,disconnection of β-endorphinergic tract(fromAR to PAG)and microinjection of naloxone or anti-β-endorphin serum intoPAG would make the effect of EA disappear.Thus,it is the β-endorphinergicpathway between AR and PAG-NRM system that mediates the major excitatoryeffect of EA on NRM.更多还原