Behavior-induced zif268 expression within the DG. (a) In the suprapyramidal blade, exploration of a novel environment induced zif268 in a comparable number of granule cells in both the immediate (white) and delay (grey) groups that was significantly greater than zif268 expression in caged controls (black). (b) While the number of granule cells expressing zif268 during an episode of rest (i.e., cells transcribing zif268 while animals were in the home cage would correspond to cells expressing cytoplasmic zif268 in the immediate group and all cells expressing nuclear zif268 in the delay group, see Methods) that precedes spatial exploration (immediate) is equivalent to caged controls, significantly more granule cells express zif268 during a rest episode that follows spatial exploration (delay). Note that zif268 expression in caged control animals is depicted solely in the “rest” category since these animals were never removed from the home cage and thus their only experience was comparable to the rest period of both immediate and delay animals. In addition, significantly more zif268 expression occurred in the same cells that were active during exploration (exploration + rest). In the infrapyramidal blade, exploration of a novel environment did not significantly alter the number of granule cells expressing zif268 (c) within any cellular compartment or (d) during either epoch (all data are mean ± SEM; *p < 0.05, **p < 0.01 vs. CCs; † p < 0.05, immediate vs. delay).