Figure 1.

Memory-associated gadd45b transcription. A, FISH analysis of gadd45b expression in area CA1 in naive mouse brain. B, Quantitative PCR analysis of gadd45b reveals enrichment in striatum (p < 0.01). C, Mice were trained (3 footshock protocol described in Materials and Methods) in contextual fear conditioning (Context + Shock), exposed to the chamber only (Context) or left in home cages (Naive). Expression analysis in CA1 was performed at 30 min, 1 h, or 24 h. Gadd45b, gadd45g and Arc expression was significantly regulated by experience. Gadd45b expression was significantly suppressed compared with the context group at 30 min only (p < 0.05). D, Expression of gadd45b and gadd45g but not gadd45a was enhanced in the amygdala 1 h after training (p < 0.05). E, WT and KO primary hippocampal neuron cultures depolarized with 50 mm KCl for 2 h showed enhanced gadd45g in both genotypes. Gadd45b was upregulated in WTs (p < 0.01) (n = 4–15/group).