Strychnine is a potent, naturally occurring neurotoxin that effectively protects plants from animal pests by deterring feeding behavior. In insects, such as the fruit fly, Drosophila melanogaster, bitter-tasting aversive compounds are detected primarily through a family of gustatory receptors (GRs), which are expressed in gustatory receptor neurons. We previously described multiple GRs that eli...

Fish detect extremely low levels of marine toxins tetrodotoxin (TTX) and saxitoxin (STX) via the specialized gustatory receptor(s). Physiological and pharmacological studies show that receptor(s) for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and that TTX and STX do not share the same receptor populations, while interacting with quinine and st...

Besides taste buds, many other tissues express receptors (TR), where they exert various, often ill-explored non-gustatory functions, e.g. in immunity and metabolism. These evolutionary ancient functions of human TRs can be optimally interrogated skin, whose keratinocytes selected TRs, its dominant appendage, the hair follicle (HF). However, role skin physiology is unknown. Therefore, we have as...

Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in ...

Insect gustatory and odorant receptors (GRs and ORs) form a superfamily of novel transmembrane proteins, which are expressed in chemosensory neurons that detect environmental stimuli. Here we identify homologues of GRs (Gustatory receptor-like (Grl) genes) in genomes across Protostomia, Deuterostomia and non-Bilateria. Surprisingly, two Grls in the cnidarian Nematostella vectensis, NvecGrl1 and...

Mechanisms for Taste Sensation of Carbonation David Yarmolinsky Carbonation, or the presence of carbon dioxide (CO2) dissolved in solution, is a commonly encountered feature of beverages in the contemporary human diet. While the popularity of carbonation may be attributed to its distinct sensory qualities, the specific orosensory pathways mediating CO2 detection in mammals have not previously b...

background and aims. the majority of complete denture wearers are old. clinical experience suggests that complete denture wearers have various disorders in their gustatory and olfactory senses due to disturbance of airways between the oral and nasal cavities caused by upper complete denture. the purpose of this study was to evaluate the effect of upper complete denture on gustatory and olfactor...

The sense of taste is an essential chemosensory modality that enables animals to identify appropriate food sources and control feeding behavior. In particular, the recognition of bitter taste prevents animals from feeding on harmful substances. Feeding is a complex behavior comprised of multiple steps, and food quality is continuously assessed. We here examined the role of pharyngeal gustatory ...

The rostral nucleus of the solitary tract (rNST) is the first central relay in the gustatory pathway. While previous investigations have provided a wealth of information on the pattern of central terminations of gustatory afferent fibers, the morphology of synaptic connections of rNST neurons and responses of second order neurons to taste stimuli applied to the tongue, little is known regarding...

Regulation of feeding is essential for animal survival. The pharyngeal sense organs can act as a second checkpoint of food quality, due to their position between external taste organs such as the labellum which initially assess food quality, and the digestive tract. Growing evidence provides support that the pharyngeal sensory neurons regulate feeding, but much is still unknown. We found that a...