Objective   To investigate the effects of lithium on brain development, leaning and memory capacity, and to observe the effects of lithium chloride on rat body weight, learning ability and memory capacity.

  Methods   Wistar rats were randomly divided into control group and four lithium chloride(LiCl)(3, 30, 300, 3 000 mg/kg)groups.Four LiCl groups were fed with food containing 3, 30, 300, 3 000 mg/kg LiCl respectively.Control group was fed with normal food.By means of measuring the body weight, using Y-maze test and NADPH-d histochemitry, the difference of the body weight gains and Y -maze training times of different groups were observed.

  Results   Compared with control group, 3, 30 mg/kg LiCl groups could increase the body weight and improve the ability of learning and memory in rats(P < 0.01).The rats of 300, 3 000 mg/kg LiCl group were lower(P < 0.05).

  Results   Compared with control group, 3, 30 mg/ kg LiCl groups could increase the body weight and improve the ability of learning and memory in rats(P < 0.01).The rats of 300, 3 000 mg/kg LiCl group w ere low er (P < 0.05).Results of NADPH-d histochemistry: the activation of NOS positive neurons of 30, 300 mg/kg LiCl groups was higher than that of control group(P < 0.05), and the activation of 3 000 mg/kg LiCl group was lower than that of control group(P < 0.05).

  Conclusion   Low dose of lithium could improve the growth, the learning ability and the memory capacity obviously, buthigh dose of lithium could result in harmful effects.