Figure 2.

Distribution of Arc mRNA upregulation across the rostrocaudal axis of the hippocampus after activation of recent and long-term spatial memories. Red stars and circles indicate data for dHC and vHC of the WMT group. Blue and light-gray symbols indicate swimming and naive controls, respectively. Neurons with enhanced Arc mRNA expression were located at multiple rostrocaudal levels in DG (A, B), CA3 (C, D), CA1 (E), and subiculum (G, H) 30 min after the set of three 1 min probes of recent (A, C, E, G) and remote (B, D, H) memories. There was no distributed learning-specific signal in CA1 after long-term memory recall (F). For detailed statistical analyses, see Figures 6 and 7 and supplemental Tables 1-4 (available at www.jneurosci.org as supplemental material). Data points are individual mean values of the normalized Arc mRNA levels obtained for an anatomical match in every triad. Arrows indicate direction toward the hippocampal poles. mm, Millimeter.