Characterization of adult neurogenesis in Acomys cahirinus by lineage tracing analysis

Adult neurogenesis, the process by which new neurons are generated in the adult brain, is a complex phenomenon with implications for brain development and plasticity throughout life. Adult mice and rats present neurogenic niches in the dentate gyrus of the hippocampus, which produce new granular neurons. Acomys cahirinusis a new mammalian regeneration model that features extraordinary regenerative abilities, including full section of injured spinal cord. Adult neurogenesis and how it potentially contributes to brain repair in A. cahirinus has not been addressed. Transgenic Cre recombinase-expressing A. cahirinus have not been developed and are not available to date, thus making lineage tracing of newborn neurons challenging. To characterize the adult neurogenic niches in A. cahirinus and develop a strategy to lineage-trace newborn neurons, 12-week-old A. cahirinus and 8-10-week-old Mus musculus were injected with a dual vector combining Cre recombinase (AAV.PHP.eB.GFAP.CRE) and a reporter (AAV5.Synapsin-FLEX-EGFP). The viral vectors were delivered via intracerebral injection by stereotaxic surgery in the subgranular zone of the hippocampus. 8 weeks after viral transduction, the brains were collected and processed for immunohistochemistry. Our data shows that both animals present EGFP+ new neurons, 8 weeks after viral injection. Together with cell markers for different neurogenic stages (GFAP, Sox2, Prox1, DCX, NeuN), we observed that young adult A. cahirinus and M. musculus have neurogenic maturation compartments with different weights and dynamics. Our study underscores the potential of viral delivery in A. cahirinus as a strategy for lineage tracing for investigating neurogenesis and brain repair in vivo.