Influence of neurotrophic factor infusions into hippocampus on passive avoidance. BDNF, NT-3, NGF, or saline (SAL) was infused into the dentate gyrus or CA3, and 3 d later, passive avoidance testing was conducted as described in Materials and Methods. The results are mean ± SEM of thenumber of animals indicated under eachcolumn. Left, Day 1 (D1),F(3,35) = 1.069; p= 0.3746; day 2 (D2),F(3,35) = 0.962; p= 0.4217; right, D1,F(2,27) = 1.980; p= 0.1577; D2, F(2,27) = 0.520; p = 0.6002.