THE way your brain developed when you were a fetus or baby could determine your bodyweight for the rest of your life.
The culprit is leptin, a hormone whose levels surge after a meal, sending a “stop eating” signal to the brain. Richard Simerly’s team at the Oregon Health & Science University in Portland has now shown that in mice at least, the hormone is crucial for normal development of the circuits in the region of the hypothalamus that regulates appetite (Science, vol 304, p 108). Mice with a mutation that makes them leptin-deficient had fewer nerve connections in this area. Restoring leptin levels to normal…
