维生素A缺乏对幼鼠脑发育和学习记忆的影响

EFFECTS OF VITAMIN A DEFICIENCY ON BRAIN DEVELOPMENT, LEARNING AND MEMORY IN YOUNG RATS

目的 : 探讨维生素 A缺乏 ( VAD)对幼鼠脑发育和学习记忆能力的影响。方法 : 建立 VAD母鼠及其子代幼鼠模型。观察子代幼鼠生长发育情况 ,并测定 7w龄幼鼠学习记忆能力 ,海马和皮层蛋白质含量、细胞增殖周期及海马神经细胞超微结构改变。结果 : ( 1 ) VAD组幼鼠体重增长明显慢于对照组 ;( 2 ) VAD组幼鼠学习次数明显多于对照组 ( P<0 .0 5 ) ,记忆时间明显短于对照组 ( P<0 .0 1 ) ;( 3) VAD组幼鼠海马及皮层蛋白质含量显著低于对照组 ( P<0 .0 1 ) ;( 4 )VAD组幼鼠海马和皮层细胞增殖指数 ( PI)明显高于对照组 ( P<0 .0 1 ) ;( 5 ) VAD组幼鼠海马锥体细胞之间突触联系数量减少 ,突触内突触小泡减少 ,星形胶质细胞增多 ,且有固缩变性。结论 : VAD会导致幼鼠脑发育受损和学习记忆能力下降。

Objective: To study the effects of vitamin A deficiency (VAD) on brain development, learning and memory ability in young rats. Methods: A model of VAD in female rats and the offsprings were established. The growth and development, learning and memory ability, protein content, cell proliferative cycle of cortex and hippocampus, and hippocampus cell ultrastructure changes under electron microscopy of young rats were detected. Results: (1) The weights gain in VAD rats were decreased compared with the control. (2) The learning and memory scores in VAD rats was significantly lower than those of the control. (3) The protein content of cortex and hippocampus in VAD rats were significantly lower than those of the control. (4) The cell proliferative index (PI) of cortex and hippocampus in VAD rats were higher than those of the control. (5) The synapses between hippocampus pyramidal cells and the small bubbles in synapses in VAD rats were significantly decreased compared with the control. The astrocytes of hippocampus in VAD rats were significantly increased. Degeneration was observed in many astrocytes in VAD rats. Conclusion: VAD can affect the brain development and the ability of learning and memory in young rats.