Leptin is a peptide hormone secreted by adipose tissue. Studies have shown that leptin
crosses the blood–brain barrier (BBB) by a saturable transport system where it acts within
the hypothalamus to regulate food intake and energy expenditure. Leptin also acts in the
hippocampus where it facilitates the induction of long-term potentiation and enhances
NMDA receptor-mediated transmission. This suggests that leptin plays a role in learning and
memory. Obese mice and rats, which have leptin receptor deficiency, have impaired spatial …