Leptin receptor reactivation restores brain function in early-life Lepr-deficient mice

Obesity is a chronic disease caused by excessive fat accumulation that impacts the body and brain health. Insufficient leptin or leptin receptor (LepR) are involved in the disease pathogenesis. Leptin is involved with several neurological processes, and it has critical developmental roles. We have previously demonstrated that leptin deficiency in early life leads to permanent developmental problems, including energy homeostasis imbalance, melanocortin and reproductive system alterations and brain mass reduction in young adult mice. Since in humans, obesity has been associated with brain atrophy and cognitive impairment, it is important to determine the long-term consequences of early life leptin deficiency in brain structure and memory function. Here, we demonstrate that leptin-deficient mice (LepOb) exhibit altered brain volume, decreased neurogenesis and memory impairment. Similar effects were observed in animals that do not express the LepR (LepRNull). Interestingly, restoring the expression of LepR in 10-week-old mice reverses brain atrophy, as well as neurogenesis and memory impairments in older animals. Our findings indicate that leptin deficiency impairs brain development and memory, which are reversible by restoring leptin signaling in adulthood.