Adolescent Sugar-Induced Miswiring of Hippocampal Neurons Drives Adult Motivational Dysfunction in rats

Adolescence, a critical period for hippocampal maturation, involves the integration of newly generated neurons into circuits underlying adult behavior. While adolescent, but not adult, sugar overconsumption triggers lasting motivational deficits, the underlying mechanisms remain unclear. Here, we demonstrate that adolescent-born dentate gyrus granule neurons causally mediate adult reward-seeking behavior. Strikingly, sucrose overconsumption during adolescence abolishes this function, inducing selective remodeling of synaptic inputs and disrupting their functional integration.