Researchers from the Vanderbilt University School of Medicine Basic Sciences have uncovered the first example of activity-dependent development of hypothalamic neural circuitry . Although previous research has shown that the hormone leptin acts directly on hunger neurons through leptin receptors to promote the development of neural circuitry, results that will be published in PNAS on Nov. 25 indicate that certain neurons that do not express leptin receptors are nonetheless sensitive to its activity.
The research, led by the lab of Richard Simerly, Louise B. McGavock Professor and professor of molecular physiology and biophysics, also supports a novel role for leptin in specifying the development of neural circuits involved in autonomic regulation and food intake . His lab found that silencing the activity of hunger neurons (called "AgRP" neurons) during the critical, postnatal period of neuronal circuitry development may exert lasting effects on the structure and function of circuits that control energy balance.
Leptin is a hormone that, in adults, regulates hunger by providing a sensation of satiety and helps maintain body weight on a long-term basis. In the weeks following birth, however, leptin also helps direct the formation of circuits that control homeostatic functions. In their PNAS paper, the Simerly lab describes three primary results: Leptin is required for the normal development of neural connections between hypothalamic oxytocin neurons, which link AgRP neurons wi.