The molecular receptive range of an odorant receptor

An odor perception is the brain's interpretation of the activation pattern of many peripheral sensory neurons that are differentially sensitive to a w ide variety of odors. The sensitivity of these neurons is determined by whi ch of the thousand or so odor receptor proteins they express on their surfa ce. Understanding the odor code thus requires mapping the receptive range o f odorant receptors. We have adopted a pharmacological approach that uses a large and diverse pool of odorous compounds to characterize the molecular receptive field of an odor receptor. We found a high specificity for certai n molecular features, but high tolerance for others-a strategy that enables the olfactory apparatus to be both highly discriminating, and able to reco gnize several thousand odorous compounds.