Adult neurogenesis is the process of generating new neurons from neural stem cells (NSCs) in the adult brain, a type of plasticity highly conserved through evolution. Zebrafish exhibits abundant adult neurogenesis in their pallial sub-regions. Of particular interest are the dorsomedial (Dm) and dorsolateral (Dl) pallium, because these structures share homology with the basolateral amygdala and the mammalian hippocampus, respectively.
To explore the NSCs differentiation, we labeled a cohort of dividing NSCs with the thymidine analog EdU to study their differentiation process over time. We found that the distribution of EdU+ cells decreases along the rostrocaudal axis in Dm, whereas the opposite pattern occurs in Dl. Furthermore, we found that the number of EdU+ cells decreases in all regions after eight weeks, indicating cellular death. Interestingly, we found that Dm EdU labeled-NSCs continue proliferating throughout the eight weeks period, whereas Dl NSCs decrease their proliferation two weeks after EdU labeling. These results reveal the temporal dynamics where NSCs divide to preserve the stem cell reservoir, whereas cellular death contributes to tissue homeostasis. At this moment we are evaluating the fate that these NSCs adopt after differentiation.