Figure 1. Age-related NF-κB activation in rat hippocampus. (A) NF-κB activation in hippocampus of 4-, 12- and 24-month-old rats. The positions of both protein/DNA complexes observed are indicated as NF-κB (p50/RelA and p50/p50). NS represents nonspecific binding. The localization of free probe is also indicated. Results are representative of three experiments. (B) Densitometric analysis (arbitrary units) of the bands p50/RelA and p50/p50 presented in panel A. Results are expressed as mean + S.E.M. from three individual experiments. ANOVA followed by Newman-Keuls. (a) p<0.05 vs. 4-month-old basal sample, (b) p<0.05 vs. 12-month-old basal sample. (C) Competition studies were performed using nuclear extract (15 μg) from hippocampus of 24-month-old rats in the absence or presence of unlabeled specific (NF-κB consensus sequence, 20-fold molar excess) or non-specific oligonucleotide (TFIID consensus sequence, 20-fold molar excess), as indicated. Supershift assays were performed with the same nuclear extract (15 μg) incubated in the absence or presence of antibodies against subunits p50 (1:20 dilution) and p65 (1:20 dilution) as indicated. Antibodies were added 20 min prior to addition of the radiolabeled NF-κB consensus oligonucleotide. The positions of specific NF-κB/DNA binding complexes p50/p50 and p50/p65 are indicated. NS represents nonspecific binding. The localization of the free probe is also indicated.