Given the current 'epidemic' of obesity and its related diseases (including type 2 diabetes and heart disease), understanding how food intake, body composition, and energy expenditure are regulated has become a research priority. One soluble molecule found to regulate all these processes, and more, is leptin. Leptin causes many of its effects by acting on nerve cells in different regions of the brain, but exactly what effects each brain region mediates has not been clearly determined. However, Lori Zeltser and Laurence Ring have now generated mice in which leptin signaling is disrupted in only the hypothalamic region of the brain and shown that leptin signals in the hypothalamus are required to prevent the development of obesity up to 8 weeks of age. After 8 weeks of age, leptin signals in regions of the brain other than the hypothalamus were able to control further development of obesity, although they could not reverse obesity established prior to 8 weeks of age. The authors suggest that these data might have implications for combating childhood obesity.
TITLE: Disruption of hypothalamic leptin signaling in mice leads to early-onset obesity, but physiological adaptations in mature animals stabilize adiposity levels
AUTHOR CONTACT: Lori M. Zeltser Columbia University, New York, New York, USA. Phone: 212.851.5314; Fax: 212.851.5306; E-mail: email@example.com.