The goal of this study was to obtain preclinical proof-of-concept that allopregnanolone (APα) can function as a regenerative factor with an impact on cognitive function in AD. To  this end the authors investigated the efficacy of APα  in promoting neurogenesis in the hippocampal subgranular zone (SGZ), and reversing learning and memory deficits in the 3xTg AD mouse model. Using this AD model, the authors characterized APα concentration in brain and serum, basal level of neurogenesis, and  impact on cognitive function mice at 3 months of age. Data showed that APα, after a single injection, reversed deficits in SGZ neurogenesis, reversed cognitive deficits and restored learning and memory performance to the level of normal non-Tg mice. In addition, APα-induced survival of neural progenitors was significantly correlated with APα-induced memory performance.  At 3 months, basal level of neuroprogenitors  in the SGZ of 3xTgAD mice was significantly lower relative to non-Tg mice, despite the lack of evident AD pathology.These findings suggest that early neurogenic deficits, which were evident before immunodetectable Aβ, may contribute to the cognitive phenotype of AD and that APα could serve as a regenerative therapeutic to prevent or delay neurogenic and cognitive deficits associated with mild cognitive impairment and Alzheimer’s disease.