The Saper laboratory works on neural circuitry that underlies several basic and related hypothalamic functions, including circadian rhythms; wake-sleep cycles; thermoregulation; and feeding and metabolic control. We study brain circuitry that regulates these functions using a combination of cutting-edge neuroscience methods, including opto- and chemogenetics; fiber photometry; and use of animals with loxP sites inserted in key genes, which can then be disabled by injection of adeno-associated viral vectors that express Cre recombinase. This is combined with measuring EEG/EMG, body temperature, locomotor activity, feeding, brown adipose activation, and other physiological and behavioral measures.