Hippocampal neurogenesis: Bridging stress, cognitive decline, and therapeutic strategies for neural health.

The hippocampus plays a critical role in spatial and contextual learning, and its age-related decline significantly contributes to cognitive impairment. Adult hippocampal neurogenesis (AHN), the continuous production of new neurons in the dentate gyrus, provides a unique form of structural plasticity essential for lifelong learning and memory. AHN is notably altered in various neurodegenerative and mental health disorders characterized by cognitive deficits, suggesting its crucial involvement in maintaining neuronal populations and endogenous regenerative capacity. Given the emerging links between neurogenesis and these conditions, neurogenic therapies hold promise for improving outcomes in individuals with severe depression, cognitive impairment, and other neurodegenerative disorders. Notably, chronic stress is a significant factor influencing AHN, often serving as an independent biomarker for dementia and strongly impacting hippocampal neurogenesis. This review explores the intricate influence of stress on AHN and examines how the inhibition of neurogenesis contributes to cognitive deficits and the progression of dementia.