Linden D, Martinez J L
Behav Neurosci. 1986 Feb;100(1):33-8. doi: 10.1037//0735-7044.100.1.33.
Leu-enkephalin (300 micrograms/kg) impaired memory of a Y-maze response in mice when the animals were trained to obtain food in one arm of the maze. The dose-response function was U-shaped, with neither 100 nor 600 micrograms/kg having any effect. Des-Tyr-Leu-enkephalin, a nonopioid peptide, had no effect at doses equimolar to the leu-enkephalin. Finally, the leu-enkephalin (300 micrograms/kg) was without effect if the drug injection was delayed 90 min. The results show that leu-enkephalin affects appetitive conditioning in much the same way as avoidance conditioning, a finding that suggests that leu-enkephalin may generally influence learning and memory.
当小鼠被训练在Y型迷宫的一个臂中获取食物时，亮氨酸脑啡肽（300微克/千克）损害了它们对Y型迷宫反应的记忆。剂量反应函数呈U形，100微克/千克和600微克/千克均无任何作用。去酪氨酸亮氨酸脑啡肽，一种非阿片肽，在与亮氨酸脑啡肽等摩尔剂量时没有作用。最后，如果药物注射延迟90分钟，亮氨酸脑啡肽（300微克/千克）则没有效果。结果表明，亮氨酸脑啡肽影响食欲条件反射的方式与回避条件反射大致相同，这一发现表明亮氨酸脑啡肽可能普遍影响学习和记忆。
