Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.

Therapeutic potential of ectopic olfactory and taste receptors

Olfactory detection of prostate cancer by dogs sniffing urine: A step forward in early diagnosis

Primates have traditionally been regarded as vision-oriented animals with low olfactory ability, though this "microsmatic primates" view has been challenged recently. To clarify when and how degeneration of the olfactory system occurred and to specify the relevant factors during primate evolution, we here examined the olfactory receptor (OR) genes from 24 phylogenetically and ecologically diverse primate species. The results revealed that strepsirrhines with curved noses had functional OR gene repertoires that were nearly twice as large as those for haplorhines with simple noses. Neither activity pattern (nocturnal/diurnal) nor color vision system showed significant correlation with the number of functional OR genes while phylogeny and nose structure (haplorhine/strepsirrhine) are statistically controlled, but extent of folivory did. We traced the evolutionary fates of individual OR genes by identifying orthologous gene groups, demonstrating that the rates of OR gene losses were accelerated at the ancestral branch of haplorhines, which coincided with the acquisition of acute vision. The highest rate of OR gene loss was observed at the ancestral branch of leaf-eating colobines; this reduction is possibly linked with the dietary transition from frugivory to folivory because odor information is essential for fruit foraging but less so for leaf foraging. Intriguingly, we found accelerations of OR gene losses in an external branch to every hominoid species examined. These findings suggest that the current OR gene repertoire in each species has been shaped by a complex interplay of phylogeny, anatomy, and habitat; therefore, multiple factors may contribute to the olfactory degeneration in primates.

/pdf/acceleration-of-olfactory-receptor-gene-loss-in-primate-28kobksy6e.pdf

Acceleration of Olfactory Receptor Gene Loss in Primate Evolution: Possible Link to Anatomical Change in Sensory Systems and Dietary Transition.

Social cues must be detectable by receivers or bystanders before they can respond to the information contained in the cue. Information about conspecifics and heterospecifics can be extracted from social cues. At that point, the information in the cue becomes a fact and the cue becomes a signal. Chemical signals, such as scent marks, provide accurate information that can be used by conspecifics in sexual and social contexts. Scent marks of many conspecifics distributed in an area may be akin to a chemical bulletin board that provides information about the identity of senders and how recently they were in that area. These scent marks deposited by senders can provide both private and public information to receivers. The manner in which receivers use this information to make decisions will depend on the context and manner in which it encounters these scent marks. Thus, a learned rule of thumb that will allow the animal to respond in a predictable way to a scent mark and when to scent mark would not suffice. The sender and the receiver must identify the phenotype and genotype of their counterparts, recollect interactions with them, be aware of their own condition and the context of the communication. Higher level cognitive processing would likely be required for receivers and senders to make potentially informed decisions that reflect tradeoffs in their survival and fitness.

Chemical Signals in Vertebrates 9

Mammalian survival depends on ultrasensitive olfactory detection of volatile sulfur compounds, since these compounds can signal the presence of rancid food, O2 depleted atmospheres, and predators (through carnivore excretions). Skunks exploit this sensitivity with their noxious spray. In commerce, natural and liquefied gases are odorized with t-BuSH and EtSH, respectively, as warnings. The 100-million-fold difference in olfactory perception between structurally similar EtSH and EtOH has long puzzled those studying olfaction. Mammals detect thiols and other odorants using odorant receptors (ORs), members of the family of seven transmembrane G-protein-coupled receptors (GPCRs). Understanding the regulator cofactors and response of ORs is particularly challenging due to the lack of X-ray structural models. Here, we combine computational modeling and site-directed mutagenesis with saturation transfer difference (STD) NMR spectroscopy and measurements of the receptor response profiles. We find that human thiol...

Smelling Sulfur: Copper and Silver Regulate the Response of Human Odorant Receptor OR2T11 to Low-Molecular-Weight Thiols

Olfaction enables most mammalian species to detect and discriminate vast numbers of chemical structures called odorants and pheromones. The perception of such chemical compounds is mediated via two major olfactory systems, the main olfactory system and the vomeronasal system, as well as minor systems, such as the septal organ and the Grueneberg ganglion. Distinct differences exist not only among species but also among individuals in terms of their olfactory sensitivity; however, little is known about the mechanisms that determine these differences. In research on the olfactory sensitivity of mammals, scientists thus depend in most cases on behavioral testing. In this article, we reviewed scientific studies performed on various mammalian species using different methodologies and target chemical substances. Human and non-human primates as well as rodents and dogs are the most frequently studied species. Olfactory threshold studies on other species do not exist with the exception of domestic pigs. Olfactory testing performed on seals, elephants, and bats focused more on discriminative abilities than on sensitivity. An overview of olfactory sensitivity studies as well as olfactory detection ability in most studied mammalian species is presented here, focusing on comparable olfactory detection thresholds. The basics of olfactory perception and olfactory sensitivity factors are also described.

Olfactory sensitivity in mammalian species

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M Wackermannová

Author Tools

Chat about Author

Papers

Olfactory sensitivity in mammalian species