This is a proposal to study the food entrainable circadian oscillator, an important and much neglected aspect of the circadian system. Although we know that there is a food entrainable oscillator which is separate from the light entrainable oscillator that resides in the suprachiasmatic nucleus, we do not know where it is located, nor how signals from the food input pathway reach it and entrain it. The PI proposes a series of experiments to address these areas of ignorance.