Pattern separation and adult hippocampal neurogenesis. (a) Timeline of the experiments (TS, touchscreen; TT, task training; PT, probe trials; B, BrdU injections; OF, open field; EPM, elevated plus maze; w, weeks of age). (b) The touchscreen paradigm acquisition of big and small separation between two identical stimuli was tested in control (CON) and (−)epicatechin (EC)-treated mice, which were trained to reach a criterion where seven of eight trials were performed correctly. Pattern separation did not differ between the CON and EC groups when the separation between the stimuli was either large or small. (c) Bromodeoxyuridine (BrdU)-positive cell number did not differ between the groups. (d) The percentage of new DG neurons showed no differences between CON and EC-treated mice. Photomicrographs of new cells surviving 9 weeks after the last BrdU injection, in tissue derived from (e) CON and (f) EC-treated subjects. Neuronal phenotype was determined by double-labeling for BrdU (green) and NeuN (red) in (g) CON and (h) EC-treated mice. Error bars denote s.e.m.