摘要
本文用ＳｐｒａｑｕｅＤａｗｌｅｙ人鼠为实验动物，从生后一日龄起每日皮下分别注射１次纳洛酮（１０，５０，１００，２００μｇ／１００ｇｂ．ｗ）、甲硫氨酸脑啡肽（ＭＥＫ）（２０μｇ／１００ｇｂ．ｗ），对照组注射等量的生理盐水。连续注射１４ｄ，观察１６日龄幼鼠的吸乳迷津分辨学习（ＡＤＬ）、３０日龄幼鼠的Ｙ迷津明暗分辨学习（ＢＤＬ）行为与４５日龄幼鼠前脑蛋白含量的变化。结果表明，５０μｇ／１００ｇｂ．Ｗ纳洛酮能显著抑制幼鼠的ＡＤＬ和ＢＤＬ学习能力，使前脑的蛋白质含量降低。２００μｇ／１００ｇｂ．ｗ纳洛酮则可明显促进ＢＤＬ学习能力，前脑蛋白含量增加。ＭＥＫ抑制ＢＤＬ行为，但对ＡＤＬ无明显的影响。实验结果提示在生后脑发育过程中，阿片肽能影响幼鼠的ＡＤＬ和ＢＤＬ行为，其原因可能和脑内蛋肉质含量的变化有关。
Infant Spraque-Dawley rats were divided into several groups and received daily injection of saline,naloxone(10,50,100 or 200μg/100gb.w)or Met-enkephalin(MEK 20 μg/100 g b.w)respectively from postnatal days 1-14.They were trained in the appetitive discrimination learning(ADL) at the age of 16 days,then in the bright discrimination learning of Y-maze(BDL)at 30 days of age.On days 45, the content of brain protein of the rats was examined.Results showed that the dose of 50μg/ 100 g b.w.of naloxone significantly inhibited learning behavior in ADL and BDL and lowerd the content of brain protein of the pups.The dose of 200μg/100 g b.w.of naloxone had the opposite effects.No singnificant effects were seen for the other doses of naloxone.Whereas,MEK inhibited learning of the infant rats in BDL.Results suggest that the endogenous opioid system may influence some behavior during postnatal brain development of infant rats.
