Odor response properties of rat olfactory receptor neurons

Molecular biology studies of olfaction have identified a multigene family o f molecular receptors that are Likely to be involved in odor transduction m echanisms. However, because previous functional data on peripheral coding w ere mainly collected from inferior vertebrates, it has been difficult to do cument the degree of specificity of odor interaction mechanisms. As a matte r of fact, studies of the functional expression of olfactory receptors have not demonstrated the Low or high specificity of olfactory receptors. In th is study, the selectivity of olfactory receptor neurons was investigated in the rat at the cellular Level under physiological conditions by unitary ex tracellular recordings. Individual olfactory receptor neurons were broadly responsive to qualitatively distinct odor compounds. We conclude that perip heral coding is based on activated arrays of olfactory receptor cells with overlapping tuning profiles.