[Effects of lithium on rat hippocampus cholecystokinin protein expression and learning and memory].

Objective: To investigate the effects of lithium on brain development, leaning and memory, we observed 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) groups. Four LiCl groups were feed with food containing 3, 30, 300, 3000 mg/kg LiCl respectively. Control group was feed with normal food. By means of measuring the body weight, using Y-maze test and ABC immunohistochemistry, we observed the difference of the body weight gains and Y-maze training times of different groups, and the changes of CCK positive neurons in hippocampus.

Results: Compared with control group, 3, 30 mg/kg LiCl groups could increase the body weight and improve the ability of learning and memory of rats(P < 0.01), however, these of the rats of 300, 3000 mg/kg group were lower (P < 0.05). The numbers of CCK positive neurons in hippocampus of 3, 30, 300 mg/kg groups were significantly increased compared with control group (P < 0.05), that of 3000mg/kg group was lower than control group (P < 0.05).

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