Cellular and Molecular Neurobiology
Author: Gonzalo Carnevale | Email: gonzacarnevale@gmail.com
Gonzalo Carnevale1°3°, Emilia Delegliese1°2°3°, Luz Mazzaro3°, Nicólas Bellora3°, Lucas Mongiat1°2°
1° Departamento de Física Medica
2° Comisión Nacional de Energía Atómica
3° Universidad Nacional del Comahue
The zebrafish’ pallium is involved in learning and memory during emotional and spatial information processing. This structure can be subdivided into several regions, including the dorsomedial (Dm) and dorsolateral (Dl) pallium; where both present a high degree of adult neurogenesis and neuronal plasticity. These regions are mainly conformed by glutamatergic and GABAergic neurons. During embryonic development, the glutamatergic neurons are generated from neural stem cells (NSC) located in the periventricular zone of the pallium and early turn on the expression of neurod1. In contrast, GABAergic neurons are generated in the subpallium from Zash1a+ NSC. Here we wonder if there is GABAergic neurogenesis in the pallium of adult zebrafish. To test this, we used the transgenic adult zebrafish, tg (GAD:GFP). After intra-peritoneal EdU administration, fish were euthanised at 1.5, 3, 8 or 16 days post-injection (dpi) of EdU. Between 3 and 8 dpi, approximately 80% of EdU-positive cells express the glutamatergic marker neurod1, a value that slightly decreases at later times. In contrast, only ~3% of EdU positive cells show GFP label, indicating GABAergic phenotype. The spatiotemporal analysis of adult-born GABAergic pallial neurons support the idea that GABAergic neurons are located closer to the pallial periventricular region than the subpallial neurogenic niches. Our results support a pallial origin of adult-born GABAergic neurons in zebrafish.