Figure 4

Bdnf expression is decreased in the hippocampus and cortex of IKK2^nCAmice. (A) qRT-PCR analysis indicates significantly reduced levels of Bdnf mRNA in the hippocampus but no changes for the other analysed memory-associated genes as Ngf, Ntf3, Igf2 and Prkaca were detected (n = 4-7). P-values are derived from two-tailed-unpaired student’s t test. (B) Representative images from immunostaining of IKK2^nCA mice brains reveal a decline in Bdnf immunoreactivity in the hilus of the dentate gyrus. Inward arrows point towards the expression of Bdnf in the hilus (n = 3-5). Scale bar: 100 μm. (C) Quantification of Bdnf immunoreactivity by ImageJ64 represents decreased Bdnf expression in the dentate hilus of IKK2^nCA mice at 3M, 6M and 9M age. p-values are derived from one way ANOVA Bonferroni’s Multiple Comparison test. (D) Measurement of Bdnf concentration by ELISA indicates significant decrease in total Bdnf levels in the cortex and hippocampus of IKK2^nCA mice at 6M of age (n = 4). P-values are derived from two-tailed-unpaired student’s t test. (E) Western blot analysis demonstrates Bdnf reduction in cortex and hippocampus of IKK2^nCA mice at the age of 9M. Erk2 is used as loading control. (F) qRT-PCR shows that decreased Bdnf levels are associated with a reduced expression of Gria1 (GluR1) and Gria3 (GluR3) type AMPA receptors in the hippocampus at 3 and 9 months of age but no alterations are detected for Gria2 (GluR2) and Gria4 (GluR4) in all three age groups. p-values are derived from two-tailed-unpaired student’s t test. (A-F) Co = wild type and single transgenic littermate controls, IKK2^nCA = transgenic mice with neuron-specific expression of constitutively active IKK2. All data are shown as mean ± SEM. * p < 0.05, ** p < 0.01.