Neurogenesis in Zebrafish

This chapter provides an overview of the cellular and molecular mechanisms underlying neurogenesis, from the earliest embryonic stage until adult, focusing on the major contributions brought to the field by the zebrafish model. The mechanisms and specificities of primary neurogenesis, which occurs from the recruitment of progenitors from the earliest proneural clusters by lateral inhibition, are first described. Next, during secondary neurogenesis, neuronal and glial cell diversities are generated, in particular with the establishment of neuromodulatory circuits. Finally, and in contrast to mammals, neurogenesis in zebrafish does not stall with nervous system maturation but is constitutively maintained to account for the continuous growth and regenerating properties of the adult brain. Recent studies identified the localization, identities and properties of adult progenitors cells. Interestingly, the same proneural and neurogenic pathways seem to be reiterated at these late stages.