Subject
In our lab, we investigate diverse mechanisms of plasticity taking place in brain circuits involved in cognitive functions such as learning and memory. In particular, research in our lab is focused on adult neurogenesis, the generation of new neurons occurring in the dentate gyrus of the hippocampus. We also study how plasticity is altered in the aging brain and assess different strategies to circumvent functional decline.
Adult-born neurons develop and integrate in the preexisting circuits and play important roles in information processing. We investigate the cellular and molecular mechanisms underlying neuronal development and integration, the consequences of neurogenesis for the remodeling of host circuits, and the specific roles that new neurons play in information processing and, ultimately, behavior. We also study how new neurons change their function as they grow, to unearth processes that might later be used to protect and repair damaged networks in the adult and aging brain.

Approach
Circuit remodeling and behavior are studied in laboratory mice, utilizing molecular biology, optogenetics, electrophysiology and imaging approaches both in vivo and ex vivo. We use experimental manipulations to modify the activity of new neurons and their circuit partners, and analyze the consequences at the cellular, circuit and behavioral levels. We have recently incorporated transcriptomic analysis to dig deeper into the mechanisms underlying this exciting developmental process occurring in the adult brain and its regulation.

Advances
We have discovered that adult-born neurons display multiple developmental stages that are regulated by behavior, through mechanisms involving changes in the activity of the local circuits. Most remarkably, developing neurons undergo a hyperactive stage with functional properties that are distinct from fully mature neurons, and play fundamental roles in processing spatial information. We have also shown that neuronal development is largely delayed in the hippocampus of older mice, but it may be greatly accelerated by physical exercise or spatial exploration, revealing unsuspected levels of plasticity in the aging brain.