Figure 2. FKN reverses the age-related decrease in neurogenesis.

(A) Timeline: In experiment 1 treatment lasted for 7 days, with injections of BrdU occurring at day 6. In experiment 2, treatment lasted for 14 days, with injections of CldU occurring at day -1 and injections of IdU occurring at day 6. BrdU was used to study the effects of the treatments on proliferation of hippocampal NPC. CldU was used to study the effects of treatment on the cells born prior to the treatment. IdU was used to study the effects of survival of the cells born after treatment and to make direct comparisons with BrdU data. (B) A significant increase in proliferation as measured by the number of BrdU⁺ cells was found in the aged rats treated with FKN for 6 days. *(t₍₁₀₎=2.639; p=0.0248; FKN(n=6) vs. HI-FKN(n=6)). (C) After 7 days of FKN treatment in age rats there was no significant difference in the number of DCX⁺ cells (FKN n=4; HI-FKN n=6). (D) In the second experiment, in the cells born before treatment began (labeled with CldU) with 15 days of time for the labeled cells to survive, no difference was found between groups (FKN n=5; HI-FKN n=4). (E) When cells were labeled with IdU on day 7 (same time point as BrdU (B)) a significant increase (p=0.0065; E) in number of IDU⁺ cells was found in the FKN treated group. *(t₍₇₎=3.831; p=0.0065; FKN(n=5) vs. HI-FKN(n=4)). (F) After 14 days of treatment in aged rats, FKN significantly increased the number of DCX⁺ cells. *(t₍₈₎=2.945; p=0.0116; FKN(n=5) vs. HI-FKN(n=5)). (G) The number of IdU⁺ cells was found to strongly correlate with the number of DCX⁺. ***(Pearson r=0.933; p=0.0002).