Smad3 deficiency decreases adult neurogenesis in the DG. Mice received a daily injection of BrdU (100 mg/Kg) on five consecutive days and the survival of newborn cells was evaluated 28 days after the last injection. (A) Effect of Smad3 deficiency on the survival of newborn cells labeled with BrdU in the SGZ, GCL and the hilus. (B-C) Representation of the DG (SGZ + GCL) along the rostro-caudal axis showed that Smad3-/- mice had fewer BrdU-ir cells than Smad3+/+ in the middle and caudal regions, but not in the rostral regions (*, P ≤ 0.05; **, P ≤ 0.01 Student’s t-test, n = 5-7 mice per genotype). (D) Effect of Smad3 deficiency on progenitor differentiation to neurons (BrdU/NeuN) and (E) astrocytes (BrdU/S100β; **, P ≤ 0.01, Student’s t-test, n = 4-5 mice per genotype).