MRI study shows hormone leptin alters brains, may ease cravings of people with obesity gene

A magnetic resonance imaging (MRI) study finds that the protein hormone leptin promotes development of gray matter in the part of the brain that regulates cravings and the ability to monitor personal behavior.

After receiving leptin replacement therapy, research subjects with a recessive mutation in the obesity (ob) gene - a population both deficient in leptin and morbidly obese - lost about half of their body weight while regulating their own food intake.

The findings suggest leptin may play a role in modulating personal behavior and perhaps food cravings.

Leptin is a protein hormone that plays an important role in regulating body weight, metabolism and reproductive function. Researchers took MRI scans of research subjects' brains prior to beginning leptin replacement treatment, and again at six and 18 months after treatment began.

The lead investigators are Drs. Edythe London and Julio Licinio of the UCLA Neuropsychiatric Institute. The imaging was conducted by London and John Matochik of the National Institute on Drug Abuse.

The research appears in the May 2005 edition of the Journal of Clinical Endocrinology & Metabolism.

National Institutes of Health (National Institutes of General Medical Sciences, National Center for Research Resources, National Institute of Mental Health, National Institute on Drug Abuse).

http://www.ucla.edu