Fig. 2.

Acquisition of big and small separation between stimuli. Mice were trained to reach a criterion of seven of eight trials correct. (A) Runners (run) performed better than controls (con) in acquisition in the small separation condition (*P < 0.05) but not in the big separation condition (P > 0.24). (B) Trend toward a correlation between trials to acquisition of the small separation and newly born neuron density was observed (P = 0.13). Photomicrographs of BrdU-positive cells in control (C) and runner (D) dentate gyrus 10 weeks after the last injection. (Scale bar: 50 μm)