Figure 1

Neurogenesis in the dentate gyrus (DG) of the adult rodent hippocampus. The adult neurogenic process encompasses several highly regulated sequential steps. The process begins with the asymmetrical division of neural stem cells (NSCs), also named quiescent neural progenitors (QNPs or type 1 progenitors), giving rise to amplifying neural progenitors (ANPs or type 2 progenitors). ANPs start to exhibit the first signs of cell-lineage commitment and eventually exit the mitotic phase to become neuroblasts (type 3 progenitors). The neuroblasts will then differentiate and migrate towards its final destination where they will fully maturate into granular neurons and establish synapses within pre-existing circuits. Each cell stage can be distinctively identifiable by cell markers, some of which are indicated. It is currently assumed that the entire process of adult neurogenesis takes around 4 to 5 weeks. (GFAP - Glial fibrillary acidic protein; DCX - Doublecortin; PSA-NCAM - Polysialylated-neural cell adhesion molecule: NeuN - Neuronal Nuclei)