Lynch T J, Tiseo P J, Adler M W
Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA.
J Ocul Pharmacol. 1990 Fall;6(3):165-74. doi: 10.1089/jop.1990.6.165.
In the rat, the predominant pupillary effect of morphine sulfate (30 mg/kg, i.p.) is mydriasis, interrupted periodically by miotic excursions. Using infrared video pupillometry, respirometry and EEG recording, we had previously reported that miotic excursions are always correlated with the onset of EEG bursting, while mydriatic excursions are preceded by respiratory slowing and correlated with EEG burst cessation. In the current study, we found that during morphine-induced EEG bursting and related miosis, delivery of an alerting stimulus to the rat caused an immediate conversion sequence composed of respiratory slowing, burst cessation and mydriatic excursion. We also simulated morphine-induced EEG bursting through non-opioid means by delivering kindling electrical stimuli to the amygdala. When the stimulus was given during morphine-induced mydriasis, the stimulus-induced bursting resulted in a miotic excursion identical to spontaneous morphine-induced miotic excursions. These results indicate 1) that the reticular activating system is involved in morphine-induced mydriatic excursions and 2) that EEG bursting is not simply correlated with morphine-induced miotic excursions, but causes them. Collectively, these results strengthen our hypothesis that the Edinger-Westphal nucleus is not the site in which the selective, receptor-mediated pupillary effects of morphine are initiated.
在大鼠中，硫酸吗啡（30毫克/千克，腹腔注射）的主要瞳孔效应是瞳孔散大，期间会周期性地被瞳孔缩小波动打断。我们之前利用红外视频瞳孔测量法、呼吸测量法和脑电图记录报告称，瞳孔缩小波动总是与脑电图爆发的开始相关，而瞳孔散大波动之前会出现呼吸减慢，并与脑电图爆发停止相关。在当前研究中，我们发现，在吗啡诱导的脑电图爆发及相关瞳孔缩小期间，对大鼠施加一个警觉刺激会引发一个由呼吸减慢、爆发停止和瞳孔散大波动组成的即时转换序列。我们还通过向杏仁核施加点燃性电刺激，以非阿片类方式模拟了吗啡诱导的脑电图爆发。当在吗啡诱导的瞳孔散大期间给予刺激时，刺激诱发的爆发会导致与自发的吗啡诱导的瞳孔缩小波动相同的瞳孔缩小波动。这些结果表明：1）网状激活系统参与了吗啡诱导的瞳孔散大波动；2）脑电图爆发不仅与吗啡诱导的瞳孔缩小波动相关，而且会引发这些波动。总体而言，这些结果强化了我们的假设，即动眼神经核不是吗啡选择性的、受体介导的瞳孔效应起始的部位。
