In Vitro Generation of Neural Cells with Regenerative Potential from Seabream Radial Glial Stem Cells: A Preliminary Study

In marine teleosts, neurotoxicity and neuropathology research is currently constrained by a lack of validated in vitro models. Although zebrafish embryonic cell cultures provide a well-established platform for investigating the cellular and biochemical mechanisms governing neuronal growth and differentiation, comparable models for marine species remain sparse. To address this methodological gap, the present study establishes a primary neuroglial cell culture system from the brain of the gilthead seabream (Sparus aurata) to investigate central nervous system (CNS) neurogenesis by characterizing the morphological, immunophenotypic, proliferative, and migratory properties of radial glial (RG) cells and their neuronal progeny. This in vitro model likely recapitulates native CNS tissue architecture, enabling the detailed examination of neural stem cell cleavage modes, stem cell niche dynamics, and radial glial scaffolding. Our findings demonstrate that seabream RG cells may act as multipotent neural stem cells, generating young neurons through asymmetric division and directing their migration along radial glial fibers. Cells actively undergoing neurogenesis within the central zones of RG colonies exhibited co-localization of PCNA and UCHL1 immunoreactivity, confirming their active proliferative state. After 3 weeks in vitro, the central core of the colonies retained proliferative stem cell niches driving ongoing neurogenesis, whereas the peripheral regions comprised differentiated GFAP-positive astrocytes interwoven with extended neuronal processes. Furthermore, time-lapse imaging of nuclear kinetics provided direct visual confirmation of neuroblast locomotion along RG scaffolding, during which migrating neuroblasts exhibited sequential nuclear dilation and elongation as structural hallmarks of active movement. These in vitro proliferative dynamics closely mirror the permanent neural plasticity of the teleost brain, constituting a valuable tool for comparative neurobiology and neurotoxicology, as well as a potentially useful resource for models of central nervous system repair.