Abstract
Neural progenitor cells in the dentate subgranular zone (SGZ) produce new cells all through life via proliferation. We observed differences in neuroblasts using doublecortin (DCX, a marker of neuronal differentiation) in the SGZ in variously aged dogs (German shepherds). In the 1-year-old group, DCX-immunoreactive (+) cells were abundantly observed in the SGZ: These cells had processes extending into the molecular layer. In the 3-year-old group, DCX+ cells were decreased by 53.0% compared to that in the 1-year-old group, and DCX+ processes were also markedly decreased. In the 6 and 8-year-old groups, DCX+ cells were decreased by 34.3% and 62.9% vs. the pre-aged group. In the 8-year-old group, DCX+ cells were decreased by 86.4% compared to that in the 1-year-old group. In the 12-year-old group, DCX+ cells and processes were nearly disappeared. This suggests that DCX+ cells processes significantly decreased at 3 years in the SGZ of the German shepherd.
