Late Maturation of Adult-Born Neurons in the Temporal Dentate Gyrus
a) The density of BrdU+ cells decreased similarly in the septal and temporal DG from 1 w to 4 w post-BrdU injection. There was a trend for less overall neurogenesis in the temporal DG (effect of cell age F1,7 = 13, P<0.01; effect of septotemporal subregion F1,7 = 4, P = 0.09; interaction F1,7 = 0.2, P = 0.7). b) Normalizing each region’s BrdU+ cell density to the 1 w value, a similar proportion of cells were lost between 1 w and 4 w in the septal and temporal DG (effect of cell age F1,7 = 12, P<0.05; effect of septotemporal subregion F1,7<0.01, P = 1; interaction F1,7<0.01, P = 1). c) In the septal DG, significantly more BrdU+ cells were initially added to the infrapyramidal blade, but by 4 weeks similar densities of cells were present in the two blades (effect of cell age F1,7 = 6, P<0.05; effect of blade F1,7 = 22, P<0.01; interaction F1,7 = 8, P<0.05; post hoc P<0.01 vs. septal supra at 1 week and septal infra at 4 weeks). d) Normalizing to BrdU+ cell densities at 1 week, in the septal DG, 80% of BrdU+ cells in the suprapyramidal blade survived to 4 weeks but only 58% in the infrapyramidal blade (not significant). †P<0.1, *P<0.05,**P<0.01.