Neurogenesis in Adult Mammals: Some Progress and Problems

Abstract

Approximately 40 years after its first report, the addition of neurons to the brains of adult mammals has now been generally accepted. We now know that several endocrine and experiential variables modulate adult neurogenesis. However, several methodological problems in its quantitative study remain. One is the use of low doses of the exogenous marker of cell proliferation, bromodeoxyuridine (BrdU). A second is the transient lifetime of most of the adult-generated cells. A third is that the survival of new neurons may depend on stimuli that are lacking in standard laboratory conditions. This review considers these issues as well as the possible functions of new neurons.