Pivovarov A S, Kobylianskiĭ A G, Bakalkin G Ia
Zh Vyssh Nerv Deiat Im I P Pavlova. 1988 Mar-Apr;38(2):333-41.
Opioid mu-agonist morphine, delta-agonist D-Ala2,D-Leu5-enkephalin (DADL) and kappa-agonist bremazocine locally applied to the surface of turtle visual cortex inhibited the orthodromic evoked potential (EP; fast negative component N1). The lack of cross-desensitization to the inhibitory action of opioids upon EP indicates that the drugs exert their effects via different opioid receptors. Morphine and bremazocine predominantly inhibited the left cortex EP, whereas DADL was a potent inhibitor of the right cortex EP. Thus opioid receptors which modulate evoked electrical activity of the left visual cortex (LVC) apparently belong mostly to mu- and kappa-type while delta-receptors were predominantly responsible for the modulation of electrical activity in the right visual cortex (RVC). Application of LVC- and RVC-extracts to the cortex surface led to EP inhibition, which was partially (60-80%) prevented by antagonist naloxone. LVC-extract proved to be a more potent inhibitor of the left cortex EP, whereas RVC-extract was found to be more effective when applied to the right cortex. It is suggested that not only opioid receptors, but also their endogenous ligands are lateralized in turtle visual cortex.
阿片类μ激动剂吗啡、δ激动剂D-丙氨酸2，D-亮氨酸5-脑啡肽（DADL）和κ激动剂布马佐辛局部应用于海龟视觉皮层表面时，可抑制顺向诱发电位（EP；快速负向成分N1）。对EP上阿片类药物抑制作用缺乏交叉脱敏表明，这些药物通过不同的阿片受体发挥作用。吗啡和布马佐辛主要抑制左侧皮层EP，而DADL是右侧皮层EP的有效抑制剂。因此，调节左侧视觉皮层（LVC）诱发电活动的阿片受体显然大多属于μ型和κ型，而δ受体主要负责调节右侧视觉皮层（RVC）的电活动。将LVC和RVC提取物应用于皮层表面会导致EP抑制，拮抗剂纳洛酮可部分（60-80%）阻止这种抑制。LVC提取物被证明是左侧皮层EP更有效的抑制剂，而RVC提取物应用于右侧皮层时更有效。这表明，不仅阿片受体，而且它们的内源性配体在海龟视觉皮层中也是单侧化的。
