Chemical recognition is essential for survival and reproduction. Adaptive evolution has resulted in diverse chemoreceptor families, in which polymorphisms contribute to individual variation in chemosensation. To gain insights into the genetic determinants of individual variation in odorant recognition, we measured olfactory responses to two structurally similar odorants in a population of wild-...

Uptake, retention and release of 5 selected odorants (benzaldehyde, 2-methylpyrazine, 2-isobutyl-3-methoxypyrazine, 2-isobutylthiazole, and 2,4,5-trimethylthiazole) by recombinant rat odor-binding protein 3 (rat-OBP3) were measured in a model system under nonequilibrium conditions. Gaseous odorants were introduced into a 100 mm section of a polar deactivated capillary in which aqueous rat-OBP3 ...

Although odorant concentration-response characteristics of olfactory neurons have been widely investigated in a variety of animal species, the effect of odorant concentration on neural processing at circuit level is still poorly understood. Using calcium imaging in the silkmoth (Bombyx mori) pheromone processing circuit of the antennal lobe (AL), we studied the effect of odorant concentration o...

In over half a century numerous studies have demonstrated that different odorants produce individually different spatial patterns of neural receptor activity on the olfactory mucosa. However, the thought that these differential activity patterns could be the neural code underlying olfactory perception has not been tested directly. In the present study using operant techniques, rats were trained...

Following prolonged exposure to an odorant, C. elegans exhibits a diminished response to the odorant for several hours. This olfactory adaptation is odorant selective; animals can adapt independently to different odorants sensed by a single pair of olfactory neurons, the AWC neurons. The mechanism of olfactory adaptation is genetically complex, with different genes required for adaptation to di...

Nonassociative odor learning paradigms are often used to assess memory, social recognition and neuromodulation of olfactory pathways. We here use a modified object recognition paradigm to investigate how an important task parameter, delay between encoding and recall trials, affects the properties of this memory. We show that both memory for a previously investigated odorant and discrimination o...

Human sniffing behavior usually involves bouts of short, high flow rate inhalation (>300 ml/s through each nostril) with mostly turbulent airflow. This has often been characterized as a factor enabling higher amounts of odorant to deposit onto olfactory mucosa than for laminar airflow and thereby aid in olfactory detection. Using computational fluid dynamics human nasal cavity models, however, ...

Olfactory receptors are the largest group of orphan G protein-coupled receptors with an infinitely small number of agonists identified out of thousands of odorants. The de-orphaning of olfactory receptor (OR) is complicated by its combinatorial odorant coding and thus requires large scale odorant and receptor screening and establishing receptor-specific odorant profiles. Here, we report on the ...

The antennules of many marine crustaceans enable them to rapidly locate sources of odorant in turbulent environmental flows and may provide biological inspiration for engineered plume sampling systems. A substantial gap in knowledge concerns how the physical interaction between a sensing device and the chemical filaments forming a turbulent plume affects odorant detection and filters the inform...

Odorant receptors (ORs) form one of the largest gene families in the genome. However, the vast majority are orphan receptors as the ligands that activate them remain unknown. Deorphaning approaches have generally focused on finding ligands for particular receptors expressed in homologous or heterologous cells; these attempts have met with only partial success. Here, we outline a conceptually di...