We are interested in understanding the neural and algorithmic basis of odor-guided behaviors in terrestrial animals. To this end, we have developed behavioral tasks in mice using stimuli and situations that approximate natural settings, while allowing electrophysiological recordings, high-resolution optical imaging and optogenetic manipulation. We record neural activity in behaving mice using electro- or opto-physiological methods and relate them to behavioral features, and attempt to discern the computational algorithms underlying these behaviors. Where possible, we also examine the neural circuits to understand how their architecture gives rise to the neural activity observed in behaving animals. Finally, we are also interested in understanding how neural circuits in the olfactory system are modified by behavioral state, experience and in disease.