Marked species and age-dependent differences in cell proliferation and neurogenesis in the hippocampus of wild-living rodents.

Variations in the extent of adult neurogenesis and natural and experimental factors controlling it have been described in laboratory animals. The wide range of variation seen even within a species, the mouse, raises the question as to which rates of neurogenesis can be expected in natural populations. Answering this question is important to evaluate the functional significance of adult neurogenesis under natural conditions and to define the factors controlling it.