The perception and discrimination of thousands of different odorants by the vertebrate olfactory system results from the activation of specific olfactory neurons within the olfactory epithelium of the nose (reviewed in Buck, 2000; Firestein, 2001). Activity from these cells is then interpreted by the brain to discern the molecular identity of a given odorant stimulus. How is this process of mol...

The mammalian olfactory system can recognize and discriminate a large number of different odorant molecules. The detection of chemically distinct odorants presumably results from the association of odorous Ugands with specific receptors on olfactory sensory neurons. To address the problem of olfactory perception at a molecular level, we have cloned and characterized 18 different members of an e...

The mammalian olfactory system can recognize and discriminate a large number of different odorant molecules. The detection of chemically distinct odorants presumably results from the association of odorous ligands with specific receptors on olfactory sensory neurons. To address the problem of olfactory perception at a molecular level, we have cloned and characterized 18 different members of an ...

Different olfactory cues elicit distinct behaviors such as attraction, avoidance, feeding, or mating. In the nematode C. elegans, these cues are sensed by a small number of olfactory neurons, each of which expresses several different odorant receptors. The type of behavioral response elicited by an odorant could be specified by the olfactory receptor or by the olfactory neuron in which the rece...

The shape recognition model of olfaction maintains that odorant reception probes physicochemical properties such as size, shape, electric charge, and hydrophobicity of the ligand. Recently, insects were shown to distinguish common from deuterated isotopomers of the same odorant, suggesting the involvement of other molecular properties to odorant reception. Via two-photon functional microscopy w...

About 10% of mammalian odorant receptors are transcribed in testes, and odorant-receptor proteins have been detected on mature spermatozoa. Testis-expressed odorant receptors (TORs) are hypothesized to play roles in sperm chemotaxis, but they might also be ordinary nasal odorant receptors (NORs) that are expressed gratuitously in testes. Under the sperm-chemotaxis hypothesis, TORs should be sub...