Abstract: ObjectiveTo study the effect of extract of fetal brain (Nerval Active Factors, NAF) on learning, memory and stamina of mice.Methods51 mice were divided into five groups randomly: normal saline as Group A, Cerebrolysin as Group B, NAF as Group C:0.1mg,Group D:0.2mg,Group E:0.4mg, i.p.The time looking for food and error frequency of walking road were tested by using complicated maze, and the drowning time was tested when the mice carried 5% body weight on its back.ResultsBefore and after treatment,the time looking for food in maze showed no significant change in Group A(P>0.1) and was significantly shorter in Group B, C, D and E(P<0.005,P<0.05,P<0.001,P<0.001).There was no significant difference on error frequency of walking road in Group A and B(P>0.2,P>0.5) before and after treatment, while it was significantly decreased in mice of Group C, D and E(P<0.02,P<0.02,P<0.01).There was significant difference on drowned time of mice carrying 5% body weight on back in five groups by analysis of variance (P<0.05) after treatment, but this difference derived from C vs E(P<0.05)and D vs E(P<0.01).Conclusions NAF can raise the activity of learning and memory of mice, as well as increase their stamina. On the other hand, the stamina of mice decreases when NAF is given more than 20 mg/kg body weight.

Key words: Nerval Active Factors(NAF), learning, memory, mice