We are developing innovative viral tools to explore the synaptic integration of newborn dentate granule cells from a holistic point of view. Not only we study the establishment and maturation of synaptic contacts made onto these cells, but also the modulation of this process exerted by other elements, such as microglia, astrocytes, interneurons, and vascular elements, which orchestrate the hippocampal trisynaptic circuitry. The use of the novel viral tools developed in our lab, combined with the application of advanced microscopy techniques are currently bringing to light the complex remodeling of the hippocampal dentate gyrus neurogenic niche that occurs throughout physiological and pathological aging in mice. We are also assessing the therapeutic potential of novel strategies, either pharmacological or non-pharmacological, to reverse both the cellular and behavioral alterations observed in mouse models throughout aging and under neurodegenerative conditions. Whether or not certain mammalian species are capable of sustaining neurogenesis throughout adult life is still a matter of debate in the field. We are applying the knowledge obtained from human studies to shed some light on these crucial phylogenetic aspects.