Late Maturation of Adult-Born Neurons in the Temporal Dentate Gyrus
a) Experimental timeline. Rats received a single injection of BrdU 7, 11, 14, 21, 28 or 70 days prior to injection with kainic acid (KA) to induce seizures, which upregulate Arc expression. Rats were perfused 90 min after seizure induction for septotemporal DG histological analyses. b) Coronal sections showing anatomical boundaries used for delineating septal and temporal subregions (adapted from ). In rostral sections, the entire DG is septal (illustrated in blue). In caudal sections, the ventral half of the DG was defined as temporal (illustrated in red). Numbers indicate anterior-posterior position in mm, relative to Bregma. c) Representative confocal images of BrdU+ adult-born neurons (arrows) immunostained for Arc and NeuN. Arc expression was absent in 1-week-old cells, moderate in 3-week-old cells, and strong in 4-week-old cells. NeuN expression was observed in all cells but became progressively stronger with cell age. Scale bar, 10 µm.