【摘要】 用五管微电极在家兔疑核区记录单位活动并观察微电泳吗啡时对单位活动的影响。在54个呼吸性单位中,吗啡引起阻遏的有10个,兴奋的1个,其余43个活动无明显改变。在6个吗啡引起阻遏的单位中,有5个单位的吗啡效应可被纳洛酮对抗。在49个非呼吸性单位中,吗啡引起阻遏的有13个,兴奋的有10个,其余26个活动无明显改变。在6个吗啡引起阻遏的单位中,有5个单位的吗啡效应可被纳洛酮对抗;在7个吗啡引起兴奋的单位中,吗啡的兴奋效应均不能被纳洛酮对抗。本实验观察到疑核区的呼吸性单位有一部分能被吗啡阻遏,但呼吸性单位对谷氨酸和吗啡敏感的比例均明显地比非呼吸性单位的比例低。更多还原

【Abstract】 Our previous experiments revealed that the respiratory neurones in the region of the solitary tract are less sensitive to morphine. The possible explanation for the difference between our results and that of Denavit-Saubie was the different region observed. In this study, we observed the effects of morphine applied microiontophoretically on respiratory as well as non-respiratory neurones in the region of the nucleus ambiguus.Experiments were carried out on 24 rabbits. All the experiments were performed on conscious paralysed rabbits. The animals were bilaterally vagotomized, immobilized with gallamine triethiodide and ventilated by a respirator pump. A medical data processing computer was used on line to generate the spike frequency histograms. The effects of morphine given iontophoretically on the unit discharge rate were examined. Of the 54 respiratory (29 inspiratory and 25 expiratory) units recorded, 10 were depressed, 1 was excited and the remainder were not influenced. Naloxone administered iontophoretically blocked morphine-induced depression in 5 out of 6 trials. While applied on 49 non-respiratory units, morphine depressed 13, excited 10 and had no effect on the remaining 26 units. Naloxone blocked morphine-induced depression in 5 out of 6 trials, but did not block morphine-induced excitation.Our results indicate that the respiratory neurones in the region of the nucleus ambiguus may be depressed by morphine directly, but the percentage of depressed respiratory neurones observed is less than that of the non-respiratory neurones.更多还原