Loss of BDNF or its receptors in three mouse models has unpredictable consequences for anxiety and fear acquisition

Loss of TrkB and p75^NTR expression reduces anxiety. Testing sessions of 10 min in an elevated plus maze were carried out for each mouse and the number of entries and the time spent in the open arms measured. (A,B) Bdnf^+/− mice display unchanged anxiety levels compared to controls (n = 8 of both genotypes). (C,D) TrkB heterozygotes (n = 11) exhibit reduced anxiety compared to wild-type littermates (n = 4) evidenced by the increased time spent in the open arms (P = 0.04). (E,F), p75^NTR knockouts (n = 12) show markedly reduced anxiety levels compared to wild-type controls (n = 11) (E, P = 0.05; F, P = 0.01).