Development
Author: Fernanda Ruth Román | email: fernanda.r.roman@gmail.com
Fernanda R Román 1°2°, Julieta De Anna 1°3°, Lucas A Mongiat 1°2°
1° Departamento de Física Médica, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Argentina.
2° CONICET
3° CNEA-FONCYT
Lower vertebrates as teleost fish exhibits numerous neurogenic niches throughout their adult brain. The pallium of zebrafish is one of the most studied neurogenic regions among the teleost taxa, however little is known about the fate and distribution of the generated neurons. We recently demonstrated that cognitive activity modulates adult-born neurons addition to the zebrafish pallium. Here, we characterized the temporal dynamic of adult neurogenesis throughout the pallial subregions. To this end, we labeled a cohort of mitotic neural stem cells by EdU administration (10 mM) and followed them over time to analyze survival, proliferation and cell fate. Half of the EdU-labeled population survived after two months, indicating the death of a portion of these cells, whereas approximately a third part of neural stem cells is still proliferating for several days after labeling. Next, we characterized the neuronal fate of labeled cells by analyzing NeuroD expression (as a proxy of glutammatergic immature neurons) and GABAergic phenotype by using a tg(gad1b:GFP) fish line. We found an early and constant expression of NeuroD in EdU-labelled cells throughout the pallium, whereas the GABA-EdU colocalization decreased over time. Further experiments should be performed to discern between a possible death of GABAergic adult-born neurons or a developmental switch in gad1b expression. Our results point to a fine characterization of adult-born neurons fate in the pallium of zebrafish.