Figure 2.

Normal exploration-induced Arc expression in pyramidal cells in Egr3^−/− mice. Sample confocal images are provided (a) of proximal CA1 from WT (top row) and Egr3^−/− (bottom row) mice under baseline control (caged) conditions, versus 0 minutes (early) and 480 minutes (late) following a five-minute exposure to a novel environment (red = Arc, blue = DAPI, scale bar = 100 μm). Consistent with these images, graphs of (b) proximal CA1, (c) distal CA1, (d) CA3a/b, and (e) CA3c all show that novel exploration induces a robust increase in Arc expression immediately (0′) that is greatly reduced by 60′. At 240′ and 480′, Arc expression is no different from caged controls in any pyramidal cell region. No differences are observed between Egr3^−/− and WT mice (^∗p < 0.05 relative to caged control of the same genotype; graphs display mean ± SEM).