Early life growth and cellular heterogeneity in the short-lived African turquoise killifish telencephalon

The African turquoise killifish (Nothobranchius furzeri) is becoming a favorable model for neurobiological research. The combination of a short lifespan and a declining neuroregenerative capacity upon aging makes the killifish ideally suited for research on brain aging and regeneration. A remarkable cellular diversity makes up the young-adult killifish telencephalon, characterized by highly proliferative non-glial progenitors and four spatially distinct radial glia subtypes. In contrast to a relatively slow embryonic development, hatching is followed by a period of accelerated growth in the short-lived N. furzeri strain; GRZ. Accordingly, the brain of this teleost experiences a period of rapid expansion and maturation. In this study, we charted the growth progression of the killifish telencephalon during early post-embryonic development. We identified a dynamic cellular buildup of the neurogenic niches sustaining this explosive growth. Spatial data revealed specific differences between pallial and subpallial regions in terms of growth pace and cellular output. Spatial signatures comparable to zebrafish were identified for excitatory and inhibitory neuronal lineages, already present at hatching.