Olfactory Processing

Is the sense of smell a source of aesthetic perception? Traditional philosophical aesthetics has centered on vision and audition but eliminated smell for its subjective and inherently affective character. This article dismantles the myth that olfaction is an unsophisticated sense. It makes a case for olfactory aesthetics by integrating recent insights in neuroscience with traditional expertise about flavor and fragrance assessment in perfumery and wine tasting. My analysis concerns the importance of observational refinement in aesthetic experience. I argue that the active engagement with stimulus features in perceptual processing shapes the phenomenological content, so much so that the perceptual structure of trained smelling varies significantly from naive smelling. In a second step, I interpret the processes that determine such perceptual refinement in the context of neural decision-making processes, and I end with a positive outlook on how research in neuroscience can be used to benefit philosophical aesthetics.

En este trabajo se ha comparado la organización de los lóbulos antenales (LAs) y su representación topográfica en los cuerpos fungiformes (CFs) en soldados de dos especies de hormigas, Atta mexicana y Camponotus ocreatus. La comparación morfológica sugiere que los LAs de A. mexicana podrían ser más especializados que los de C. ocreatus a expensas de capacidades más generales. En ambas especies, el LA está organizado en seis grupos de glomérulos, cada uno inervado por su propio tracto. La inervación de las neuronas de proyección (NP), las cuales conectan los LAs con los CFs a través de los tractos antenoprotocerebrales (TAP), divide el LA en dos regiones, anterior y posterior. Los cálices de los CFs tienen varias capas que reciben información olfativa segregada: NP que inervan los grupos anteriores de glomérulos envían axones a través del TAP-lateral hacia el cuerno lateral (CL) y después hacia la capa interna del cáliz, mientras que las NP que inervan los grupos posteriores de glomérulos envían axones a través del TAP-medial a la capa externa del cáliz y después al CL. Estos resultados muestran que la organización del LA está representada topográficamente en los CFs formando un mapa odotópico. Las dos vías que conectan los LAs con los CFs podrían representar dos canales para el procesamiento de diferentes clases de olores o diferentes propiedades de los estímulos olfativos. Los resultados neuroanatómicos sugieren una organización funcional conservada en los himenópteros sociales.

Scentroid is the word leader in odour measurement equipment and services to over 37 countries around the world. Our unique instruments are used in universities, government agencies, laboratories, environmental consultants, waste water treatment plants, land fills, petrochemical plants, and many other industries that deal with odour nuisance.
Scentroid Olfactometers :
The Scentroid line of professional olfactometers and sampling equipment is designed with the vision of providing accurate, reliable, and cost effective odour measurement solutions. Manufactured by IDES Canada Inc, our model selection ranges from an ultra-portable in-field olfactometer to a fully automated state-of-the-art odor laboratory tailored to satisfy the requirements of any situation.
Scentroid Sampling Equipment :
In addition to olfactometers, Scentroid also provides advanced air sampling and storage equipment such as stainless steel Flux chamber, all-in-on vacuum chamber, Static hood, and stack diluting sampler. Our dedication to sample preservation and odour measurement accuracy is evident in our newly introduced pure PTFE sample bags. Browse our products from the menu above for complete description of our line of Olfactometers, Sampling, and Purging Equipment.

A B S T R A C T Several lines of evidence suggest that brain function and behaviour are influenced by microbial metabolites. Key products of the microbiota are short-chain fatty acids (SCFAs), including butyric acid. Butyrate is a functionally versatile molecule that is produced in the mammalian gut by fermentation of dietary fibre and is enriched in butter and other dairy products. Butyrate along with other fermentation-derived SCFAs (e.g. acetate, propionate) and the structurally related ketone bodies (e.g. acetoacetate and D-β-hydroxybutyrate) show promising effects in various diseases including obesity, diabetes, inflammatory (bowel) diseases, and colorectal cancer as well as neurological disorders. Indeed, it is clear that host energy metabolism and immune functions critically depend on butyrate as a potent regulator, highlighting butyrate as a key mediator of host-microbe crosstalk. In addition to specific receptors (GPR43/FFAR2; GPR41/FFAR3; GPR109a/HCAR2) and transporters (MCT1/SLC16A1; SMCT1/SLC5A8), its effects are mediated by utilisation as an energy source via the β-oxidation pathway and as an inhibitor of histone deacetylases (HDACs), promoting histone acetylation and stimulation of gene expression in host cells. The latter has also led to the use of butyrate as an experimental drug in models for neu-rological disorders ranging from depression to neurodegenerative diseases and cognitive impairment. Here we provide a critical review of the literature on butyrate and its effects on multiple aspects of host physiology with a focus on brain function and behaviour. We find fundamental differences in natural butyrate at physiological concentrations and its use as a neuropharmacological agent at rather high, supraphysiological doses in brain research. Finally, we hypothesise that butyrate and other volatile SCFAs produced by microbes may be involved in regulating the impact of the microbiome on behaviour including social communication.

Abstract: This paper evaluates the accuracy of the newly introduced ultra-portable olfactometer,
Scentroid SM100 developed by IDES Canada Inc, with two techniques traditionally used for
assessing ambient odours: Nasal Ranger instrument and a lung technique with the dynamic
olfactometry laboratory analysis of collected samples. A similar study was presented at the recent
NOSE 2012 odour conference [1], where the results indicated good correlation between Scentroid
SM100 and other techniques used for assessing odours: a) collection of the samples at the sources
and dispersion modeling analysis to predict off site odour concentrations and b) ambient sampling
using lung technique and odour panel evaluation by dynamic olfactometry. However, the study
was based on the data when the odour was in the range 90 ou to 3000 ou. At that time the low
ranges of the Scentroid SM100 was not studied; therefore this paper is to present data based on an
extensive study of the Scentroid SM100 when the odour concentration of ambient odour is in the
range of 2 ou to 100 ou. This time the results are compared with Nasal Ranger instrument and lung
technique used for collection of ambient samples and odour panel evaluation.

While visual and auditory perception have been investigated thoroughly during the past decades, there have only been relatively few studies on olfactory perception. In the present, ongoing study, a set of standardised smells is presented to persons of different cultural backgrounds, in order to examine cultural factors of olfactory perception and interpretation.

https://doi.org/10.1002/arch.21882

Olfaction is one of the physiological traits of insect behavior. Insects have evolved a sophisticated olfactory system and use a combined coding strategy to process general odor. Drosophila melanogaster is a powerful model to reveal the molecular and cellular mechanisms of odor detection. Identifying new olfactory targets through complex interactions will contribute to a better understanding of the functions, interactions, and signaling pathways of olfactory proteins. However, the mechanism of D. melanogaster olfaction is still unclear, and more olfactory proteins are required to be discovered. In this study, we tried to explore essential proteins in the olfactory system of D. melanogaster and conduct protein–protein interactions (PPIs) analysis. We constructed the PPIs network of the olfactory system of D. melanogaster, consisting of 863 proteins and 18,959 interactions. Various methods were used to perform functional enrichment analysis, topological analysis and cluster analysis. Our results confirmed that Class B scavenger receptors (SR-Bs), glutathione S-transferases (GSTs), and UDP-glycosyltransferases (UGTs) play an essential role in olfaction of D. melanogaster. The proteins obtained in this study can be used for subsequent functional identification in D. melanogaster olfactory.

Gas leaks in buildings can cause explosions and fire, which can result in serious burns, death and/or property damage. Since people may not smell the odorants added to natural and propane gas for a variety of reasons (e.g., being congested or asleep) electronic gas detectors could assist in detecting gas leaks. This study examined the extent to which electronic gas detectors are being used by persons reporting that they receive gas service. Three hundred seventy six participants were asked whether they have gas service at their residence and if so, what kind. Also they were asked what kinds of electronic gas detectors they had. Results showed that about half of the participants had gas service. While almost everyone reported having smoke detectors in their residence (whether or not they received gas service), less than half of the gas service users reported having a carbon monoxide detector. Very few gas service users (about 9%) reported having electronic gas detectors. Implications for warning about gas leaks and how HFE professional can aid in the production of better warnings in this domain are discussed.

This paper compares the results for ambient odour concentrations measured by three different
techniques, one of which is a new developed technology; Scentroid SM110. This new instrument was
developed recently in Canada for assessing ambient odour concentrations. The results obtained by this
instrument were compared with two other techniques presently used for assessing ambient odours: the
first technique which combines source odour testing with dispersion modelling to predict off- site odour
concentration and a second technique; direct ambient odour measurement which includes collection of
odour samples at the sensitive receptors with olfactometry analysis. In recent years in Canada, direct
ambient odour measurements are more common and are usually combined with source testing and
dispersion modelling analysis. A previous study that I carried out determined a correlation between off
- site odour concentrations estimated by dispersion modelling analysis which were based on the
measured odour emission rates at each potential odour sources and the direct ambient measurements
using odour sampling at the sensitive receptors with olfactometry analysis. Since this time however, a
new instrument- the Scentroid SM110 was developed for assessing ambient odours, and as a
continuation of my previous study, this paper shows the results between the measurements obtained
by the new instrument compared to traditional ambient sampling and olfactometry analysis. In addition
to the comparison of these two techniques, a third technique is also contrasted to this study; the Nasal
Ranger technique, which in a previous study showcased some deviancies.

A scenario based on actual cases is presented in which a consumer fails to detect a gas leak. A spark source ignites the vapor, causing an explosion and fire. Odorant added to alert people of gas leaks is not always detected for a number of reasons, including nasal congestion, sleep, odor fade, masking, and adaptation or habituation. Electronic gas sensors that alarm in the presence of explosive gas are available in the consumer marketplace and could augment leak detection.

Volatile organic compounds (VOCs) produced by plants, acting on the aphid insects during the selection and acceptance of the host, determine behavioral links between the two groups of organisms. Experimental test systems taking into account a large number of parameters defining the attractiveness or repellent properties of individual
volatile components (path length, residence time of insects within a stimulus, analysis of the impact of enantiomers), allow to focus attention of researches on the impact of VOCs on the behavior of aphids. Olfactory laboratory tests are particularly very helpful in these studies.

Krzyżanowski R., 2017. Wpływ lotnych związków na zachowanie  mszyc związane z żerowaniem. Kosmos. Seria A, Biologia / Polskie Towarzystwo Przyrodników im. Kopernika 66(3): 413-420.

Bioinspired Neural Networks have in many instances paved the way for significant discoveries in Statistical and Machine Learning. Among the many mechanisms employed by biological systems to implement learning, gain control is a ubiquitous and essential component that guarantees standard representation of patterns for improved performance in pattern recognition tasks. Gain control is particularly important for the identification of different odor molecules, regardless of their concentration. In this paper, we explore the functional impact of a biologically plausible model of the gain control on classification performance by representing the olfactory system of insects with a Single Hidden Layer Network (SHLN). Common to all insects, the primary olfactory pathway starts at the Antennal Lobes (ALs) and, then, odor identity is computed at the output of the Mushroom Bodies (MBs).  We show that gain-control based on lateral inhibition in the Antennal Lobe robustly solves the classification of highly-concentrated odors. Furthermore, the proposed mechanism does not depend on learning at the AL level, in agreement with biological literature. Due to its simplicity, this bioinspired mechanism may not only be present in other neural systems but can also be further explored for applications, for instance, involving electronic noses.

The mushroom bodies, central neuropils in the arthropod brain, are involved in learning and memory and in the control of complex behavior. In most insects, the mushroom bodies receive direct olfactory input in their calyx region. In Hymenoptera, olfactory input is layered in the calyx. In ants, several layers can be discriminated that correspond to different clusters of glomeruli in the antennal lobes, perhaps corresponding to different classes of odors. Only in Hymenoptera, the mushroom body calyx also receives direct visual input from the optic lobes. In bees, six calycal layers receive input from different classes of visual interneurons, probably representing different parts of the visual field and different visual properties. Taken together, the mushroom bodies receive distinct multisensory information in many segregated input layers.

in the article produced revive the modern state the problem of sense of smell. Shown difference approach of classification of olfactory stimulus and difficult point in that process. List some the reason for complicating efforts to create whole classification of smell. The most considerable advances in human olfactory research are noted. A mention should be made of cross-cultural investigation in the field of perception of smell. The age periodization of olfactory sensitivity is attended. Given a few examples of study relation human psychology and odors. Assigned several main research directions in olfactory sphere.