出生前照射对大鼠学习记忆行为的影响及其机制探讨

STUDY ON INFLUENCE OF RADIATION ON LEARNING AND MEMORY BEHAVIOURS IN PRENATALLY-IRRADIATED RATS AND ITS POSSIOLE MECHANISM

对妊娠第１１ｄ的孕鼠用￣（１３７）Ｃｓγ射线照射，各组仔鼠的全身平均剂量分别为０．０１５、０．１５、０．４１、０．９１和２．２Ｇｙ，观察辐射对仔鼠出生后学习记忆行为、大脑海马锥体细胞计数及海马内游离氨基酸含量的影响及剂量效应关系。结果表明，在０．１５－２．２Ｇｙ时，仔鼠条件饮水反应的每日达标率均显著低于对照组，海马锥体细胞计数显著减少，海马内羟脯氨酸含量显著增加，其显著程度随剂量增加而增大。海马锥体细胞计数和海马内羟脯氨酸含量均可与剂量表示为Ｙ＝Ａ＋ＢｌｇＤ的形式。

Pregnent Wistar rats were exposed on day 11 of gestation to `137Cs γ-rays ,the doses absorbed by their offsprings were estimated to be 0. 015,0. 15,0. 41,0. 91 or 2. 2 Gy. The influence of radiation on their postnatal learning and memory behaviours,and number of pyramidal cells and content of free hydroxyproline in the hippocampus of brain was Ob-served.The results show that for offsrings with doses of 0.15-2.2 Gy,the average dailyfrequency of conditional drinking response which can meet the assigned criteria was signifi-cantly lower than that for controls and the degree of reduction increased with doses,and thatfor these offsprings,there was a significant decrease in number of pyramidal cells,with amarked increase in content of free hydroxyproline which is in proportion to doses.The rela-tionship of change in either number of pyramidal cells or content of free hydroxypreline inhippocampus with doses can be expressed as equation of Y=A+BlgD.