Although the family of genes encoding for olfactory receptors was identified more than 15 years ago, the difficulty of functionally expressing these receptors in an heterologous system has, with only some exceptions, rendered the receptive range of given olfactory receptors largely unknown. Furthermore, even when successfully expressed, the task of probing such a receptor with thousands of odor...

The olfactory system removes correlations in natural odors using a network of inhibitory neurons in the olfactory bulb. It has been proposed that this network integrates the response from all olfactory receptors and inhibits them equally. However, how such global inhibition influences the neural representations of odors is unclear. Here, we study a simple statistical model of the processing in ...

Olfactory receptor usage is highly non-uniform, with some receptor types being orders of magnitude more abundant than others. Intriguingly, in mammals the receptors are replaced regularly and the receptor distribution changes in response to olfactory experience. We propose a theoretical model that explains these experimental observations. Our model suggests that the receptor distribution is tun...

The adult mammalian olfactory bulb (OB) is unique in that olfactory sensory neurons project directly, without prior thalamic relay, to the OB. This review discusses evidence for the direct involvement of the OB in odor perception and its modulation by olfactory experience. We first discuss recent data showing that the OB exhibits a high level of plasticity in response to olfactory experience in...

Odor coding relies on the activity of different classes of receptor neurons, each with distinct response characteristics. We have examined odor coding in a model olfactory organ, the maxillary palp of Drosophila. This organ contains only 120 olfactory receptor neurons, compartmentalized in sensory hairs called sensilla, and provides an opportunity to characterize all neurons in an entire olfact...

OBJECTIVE To analyze the efficacy of treating postviral olfactory loss with glucocorticoids, Ginkgo biloba, and mometasone furoate nasal spray. DESIGN Randomized trial. SETTING Academic research. PATIENTS Seventy-one patients who were diagnosed as having postviral olfactory loss. MAIN OUTCOME MEASURES All patients underwent olfactory function tests, including the butanol threshold test ...

Paradoxically, attempts to visualize odorant-induced functional magnetic resonance imaging (fMRI) activation in the human have yielded activations in secondary olfactory regions but not in the primary olfactory cortex-piriform cortex. We show that odorant-induced activation in primary olfactory cortex was not previously made evident with fMRI because of the unique time course of activity in thi...

The olfactory system senses odors, but not exclusively, as shown over the past years. It also registers other modalities such as temperature and pressure. However, it remains unknown how widespread these sensitivities are across species and how strongly their processing is interconnected with the processing of odors. Here, we present data on the β-glomerulus in the olfactory bulb of Xenopus lae...

The orbitofrontal cortex receives multi-modality sensory inputs, including olfactory input, and is thought to be involved in conscious perception of the olfactory image of objects. Generation of olfactory consciousness may require neuronal circuit mechanisms for the "binding" of distributed neuronal activities, with each constituent neuron representing a specific component of an olfactory perce...