后天丰富环境训练对低碘大鼠学习能力和行为损害的改善

Reduction of Learning Deficits by Enriched Environmental Stimulation in Iodine Deficiency Rats

目的 :通过给予低碘环境出生的仔鼠丰富环境的训练 ,研究对其学习能力的改善作用。方法 :对低碘环境出生的仔鼠在其脑发育临界期后 (生后30天以后 )给予丰富环境训练 ,测定条件性回避学习后巩固性条件反射建立时间、脑湿重、大脑及小脑中蛋白质和DNA含量等指标。结果 :条件性回避学习的测定显示 :训练组巩固性条件反射建立提前 ,实验总时间和非条件反射潜伏期缩短。其学习能力较未训练的低碘大鼠有明显改善 ,学习能力低下比例仅为33.3%,显著低于未给予任何训练组的68.7 %。然而两组间比较 ,在脑湿重、大脑及小脑中蛋白质和DNA含量等指标方面没有显著性差异。结论 :本实验提示 :地克病的脑发育落后虽是不可逆的 ,但后天丰富环境训练可以部分地纠正其行为缺陷 ,提高其学习能力。

Objective:To investigate the improvement effect on its learning ability by enriched environmental stimulation training to infant rats that were born in low-iodine condition.Methods: To offer enriched environmental stimulation training to infant rats at the end of critical period of its brain development (30th day after birth), and determine SCCE, brain wet weight, protein and DNA contents indexes in cerebral and cerebellum.Results: The determination of conditional avoidance learning indicates: The establishment of consolidatory conditioned reflex (CR)advanced, Total time of experiment and Latent period Non-conditioned reflex (NCR) shorten.The learning ability ameliorate significantly compared with low-iodine rats, as a result, ratio of learning ability crouching only 33.3%, markedly lower than the group without any training (68.7%).However comparation between the two groups showed that no significant difference between the indexes of brain wet weight, protein and DNA contents in cerebral and cerebellum. Conclusion: Although the lagging of brain development of Critim disease is irreversible,nurture enriched environment stimulation training can partly correct its behavior deficits,and also enhance its learning ability.