We spend nearly 1/3 of our life asleep, yet the brain circuits that are responsible for regulating this aspect of our lives remain poorly understood. Our lab studies the circuits that adjust the amount of sleep we get, govern the timing of sleep with respect to the day and night, and cause the disruption of sleep that accompanies stress, sleep apnea, aging, and neurodegenerative disorders. We also study the circuits for the daily circadian cycle of related physiological processes, such as regulation of body temperature, and behaviors such as feeding, aggression and sexual behavior. We use transgenic mice in which we can interrogate the role of different genetically identified neurons in the hypothalamus and brainstem in these processes, using opto- and chemogenetics, calcium imaging, and specific cell or gene deletions.