Fate and distribution of adult-born neurons in the pallium of zebrafish

ROMAN, FERNANDA RUTH; MONGIAT, LUCAS A

CABA

Congreso; Congreso Anual de la Sociedad Argentina de Neurociencias; 2022

Sociedad Argentina de Neurociencias

Lowervertebrates as teleost fish exhibits numerous neurogenic nichesthroughout their adultbrain.One of the most studied neurogenic regions in teleost is the palliumof zebrafish, however little is known about the dynamicsofthe generated neurons.Werecently demonstrated that the addition of adult-born neurons to thezebrafish pallium is prone to be modulated by cognitive activity. Inthis work we characterized the temporal dynamic of adult neurogenesisthroughout the pallial subregions under control conditions. To thisend, we labeled a cohort of mitotic neural stem cells by EdUadministration (10mM)and followed them over time to analyze survival, proliferation andcell fate. Half of the EdU-labeled population survived after twomonths, indicating the death of a portion of these cells, whereasapproximately a third part of neural stem cells is stillproliferating for several days after labeling. Next, we characterizedthe neuronal fate of labeled cells by analyzing NeuroD expression (asa proxy of glutammatergic immature neurons) and GABAergic phenotypeby using a tg(gad1b:GFP) fish line. We found an early and constantexpression of NeuroD in EdU-labelled cells throughout the pallium,whereas the GABA-EdU colocalization decreased over time. This resultsuggest death of GABAergic adult-born neurons or perhaps adevelopmental switch in gad1b expression during cell maturation. Ourresults point to a fine characterization of adult-born neuron’sfate in the pallium of zebrafish.