Fig. 3. Long-term maintenance of interindividual differences in adult-born neurons in the hippocampus.

Adult neurogenesis during phase 1 and phase 2 was analyzed by injection of IdU (4 weeks before the end of phase 1) and CldU (4 weeks before the end of phase 2) and quantified at the end of the experiment. (A) Increased mean and variance in numbers of new hippocampal neurons produced during phase 1 (IdU) were observed in ENR and ENR-STD mice. ENR but not ENR-STD mice showed increased levels of adult neurogenesis compared to STD mice in phase 2 (CldU). [n = 36 (STD), 39 (ENR), and 40(ENR-STD)]. Box and whisker plots: center line, median; plus sign, mean; upper and lower hinges, first and third quartiles; whiskers, highest and lowest values within 1.5 times the interquartile range outside hinges; dots, individual data points. (B) Representative images of immunohistochemical stainings for detection of IdU- and CldU-positive cells. Scale bars, 50 μm. (C) Adult hippocampal neurogenesis is repeatable between phases only in ENR mice. (D) Variance fraction that is explained by interindividual differences shows posterior distribution shifted toward positive values in ENR compared to STD and ENR-STD mice. Modes of posterior densities with 95% credible intervals are shown. (E) Phenotypic correlation of adult neurogenesis to cumulative RE (cRE) in phase 1. See table S1 and data file S1 for statistical details. See also fig. S1.