In day-to-day life during navigation, hunting, escaping from predator and social interactions, animals rely on sensory information in general and on olfactory cues in particular. A general feature common to all forms of sensory processing is adaptation, whereby in the presence of continuous stimulation, sensory receptors exhibit a marked reduction in responsiveness. Perceptual adaptation attenuates neural and perceptual responses to sustained or redundant stimulation as means of enhancing the detection of new, transient stimuli. Rapid olfactory adaptation allows an animal to continually assess changes in odor environment and concentration that are essential to follow odor plumes and trails. Current research aims to provide first insight on neural representation of complex, dynamic input by the mammalian olfactory system.Here I propose to combine precise control of odor stimulus, electrophysiology and behavioral readout in mice to ask: how olfactory system represents changes in odor concentration and how this representation depends on the statistics of the olfactory input? At the first stage responses of the olfactory system to simple switches in odor concentration will be studied. This will gain insight into the role of adaptation in the olfactory system. A second project will study how the olfactory system adapts to a time-varying stimulus with the final goal to form a quantitative description of temporal adaptation.The current research will provide the first physiological recordings in mammals in response to controllable time-varying stimulus. I will use behavioral readout to find which features of the neural code contribute to perception. Moreover, recording M/T cell activity in the context of behavioral tasks will strengthen the link between specific activity patterns and odor intensity perception. Finally, correlating specific features of the response to choice trial-by-trial will identify the features most relevant to the animals’ perceptual decision