Fentanyl, an agonist at the mu opioid receptor, depresses pupillary unrest
Fentanyl, an agonist at the mu opioid receptor, depresses pupillary unrest
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DOI：
10.1016/j.autneu.2015.01.004
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发表时间：
2015-05-01
影响因子：
2.7
通讯作者：
Larson, Merlin D.
中科院分区：
文献类型：
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作者：
Bokoch, Michael P.;Behrends, Matthias;Larson, Merlin D.
瞳孔不安是瞳孔大小的混乱波动，其在黑暗中随着困倦的开始以及在环境光中观察到。在黑暗中以及在环境光下瞳孔不稳定的机制是未知的，但研究表明，它是由Edinger-Westphal（E.W.）原子核中脑导水管周围灰质中的神经元具有振荡放电模式，这对E.W.我们的理论是，这种振荡神经元在光线下会产生瞳孔不安，并会受到阿片类药物等药物的抑制，这些药物已知会抑制中脑的抑制通路。红外瞳孔计被用来测量光对瞳孔不安的影响，在8名志愿者的科目，并在20名患者安排膝关节镜手术谁接受芬太尼作为术前用药。瞳孔不安通过快速傅立叶变换的频谱分析进行量化。对33 Hz下的16秒瞳孔大小测量值进行滤波，以消除眨眼伪影和基线漂移。在给予中等剂量的1 mcg/kg芬太尼后，抑制了40 +/-20%。观察到药物作用恢复。基于这项研究的数据，我们提出，瞳孔不安的光起源于振荡抑制神经元，间歇性抑制E。W.原子核(C)2015 Elsevier B. V.版权所有。
Pupillary unrest is a chaotic fluctuation in pupil size that is observed in darkness with the onset of drowsiness, and in ambient light. The mechanism of pupillary unrest in darkness as well as in ambient light is unknown but studies suggest that it is caused by fluctuating activity in the Edinger-Westphal (E.W.) nucleus. Neurons in the periaqueductal gray with oscillating firing patterns that are inhibitory to the E.W. nucleus have been described in the cat. We theorized that such oscillating neurons produce pupillary unrest in light and would be depressed by agents, such as opioids, known to depress inhibitory pathways in the midbrain. An infrared pupillometer was used to measure the effect of light on pupillary unrest in eight volunteer subjects, and on 20 patients scheduled for knee arthroscopy who received fentanyl as premedication. Pupillary unrest was quantified through spectral analysis of fast Fourier transforms. Sixteen-second measurements of pupil size at 33 Hz were filtered to eliminate blink artifacts and baseline drift Pupillary unrest was augmented by excitation of the E.W. nucleus by light and was depressed by 40 +/- 20% after the administration of the moderate dose of 1 mcg/kg of fentanyl. Recovery from the drug effect was observed. Based upon the data from this study we propose that pupillary unrest in light originates within oscillating inhibitory neurons that intermittently depress the E. W. nucleus. (C) 2015 Elsevier B.V. All rights reserved.