scholarly journals A Near Complete Zonal Map of Mouse Olfactory Receptors

2017 ◽  
Author(s):  
Longzhi Tan ◽  
X. Sunney Xie
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory System ◽  
Olfactory Receptors ◽  
Mrna Abundance ◽  
Topological Map ◽  
Main Olfactory Epithelium ◽  
Regulated Expression ◽  
Or Genes

AbstractIn the mouse olfactory system, spatially regulated expression of > 1,000 olfactory receptors (ORs) ― a phenomenon termed “zones” ― forms a topological map in the main olfactory epithelium (MOE). However, the zones of most ORs are currently unknown. By sequencing mRNA of 12 isolated MOE pieces, we mapped out zonal information for 1,033 OR genes with an estimated accuracy of 0.3 zones, covering 81% of all intact OR genes and 99.4% of total OR mRNA abundance. Zones tend to vary gradually along chromosomes. We further identified putative non-OR genes that may exhibit zonal expression.

scholarly journals Extinction reverses olfactory fear-conditioned increases in neuron number and glomerular size

2015 ◽  
Vol 112 (41) ◽  
pp. 12846-12851 ◽  
Author(s):  
Filomene G. Morrison ◽  
Brian G. Dias ◽  
Kerry J. Ressler
Keyword(s):  
Olfactory Bulb ◽  
Learning And Memory ◽  
Olfactory Epithelium ◽  
Olfactory System ◽  
Structural Changes ◽  
Freezing Behavior ◽  
Extinction Training ◽  
Odor Stimulus ◽  
Main Olfactory Epithelium ◽  
Odor Learning

Although much work has investigated the contribution of brain regions such as the amygdala, hippocampus, and prefrontal cortex to the processing of fear learning and memory, fewer studies have examined the role of sensory systems, in particular the olfactory system, in the detection and perception of cues involved in learning and memory. The primary sensory receptive field maps of the olfactory system are exquisitely organized and respond dynamically to cues in the environment, remaining plastic from development through adulthood. We have previously demonstrated that olfactory fear conditioning leads to increased odorant-specific receptor representation in the main olfactory epithelium and in glomeruli within the olfactory bulb. We now demonstrate that olfactory extinction training specific to the conditioned odor stimulus reverses the conditioning-associated freezing behavior and odor learning-induced structural changes in the olfactory epithelium and olfactory bulb in an odorant ligand-specific manner. These data suggest that learning-induced freezing behavior, structural alterations, and enhanced neural sensory representation can be reversed in adult mice following extinction training.

scholarly journals Gonadotropin Releasing Hormone (GnRH) Modulates Odorant Responses in the Peripheral Olfactory System of Axolotls

2003 ◽  
Vol 90 (2) ◽  
pp. 731-738 ◽  
Author(s):  
Daesik Park ◽  
Heather L. Eisthen
Keyword(s):  
Glutamic Acid ◽  
Olfactory Epithelium ◽  
Olfactory System ◽  
Gonadotropin Releasing Hormone ◽  
Ambystoma Mexicanum ◽  
Stimulus Interval ◽  
Releasing Hormone ◽  
Main Olfactory Epithelium ◽  
Peripheral Olfactory System ◽  
Aquatic Salamanders

Peripheral signal modulation plays an important role in sensory processing. Activity in the vertebrate olfactory epithelium may be modulated by peptides released from the terminal nerve, such as gonadotropin releasing hormone (GnRH). Here, we demonstrate that GnRH modulates odorant responses in aquatic salamanders (axolotls, Ambystoma mexicanum). We recorded electrical field potentials (electro-olfactograms, or EOGs) in response to stimulation with four different amino acid odorants, l-lysine, l-methionine, l-cysteine, and l-glutamic acid. EOG responses were recorded from the main olfactory epithelium before, during, and after application of 10 μM GnRH. This protocol was repeated for a total of three trials with 60–80 min between trials. The effect of GnRH on EOG responses was broadly similar across odorants and across trials. In general, EOG responses were reduced to 79% of the initial magnitude during application of GnRH; in some trials in which glutamic acid served as the odorant, EOG responses were enhanced during the wash period. Although the 4-min inter-stimulus interval did not lead to adaptation of EOG responses during the first trial, we frequently observed evidence of adaptation during the second and third trials. In addition, we found that lower concentrations of GnRH produced a smaller effect. These results demonstrate that GnRH can modulate odorant responses in the peripheral olfactory system.

scholarly journals How keeping active pays off in the olfactory system

eLife ◽  
2012 ◽  
Vol 1 ◽  
Author(s):  
Kevin Monahan ◽  
Stavros Lomvardas
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory System ◽  
Main Olfactory Epithelium

A protein that is found in the main olfactory epithelium of mice ensures that odour-sensing neurons that are active to have longer lifespans than those that are inactive.

scholarly journals InsectOR – webserver for sensitive identification of insect olfactory receptor genes from non-model genomes

2020 ◽  
Author(s):  
Snehal D. Karpe ◽  
Vikas Tiwari ◽  
Sowdhamini Ramanathan
Keyword(s):  
Genome Annotation ◽  
Gene Prediction ◽  
Web Server ◽  
Olfactory Receptors ◽  
Rapid Prediction ◽  
Protein Receptors ◽  
Olfactory Receptor Genes ◽  
Or Gene ◽  
Or Genes ◽  
The Web

AbstractInsect Olfactory Receptors (ORs) are diverse family of membrane protein receptors responsible for most of the insect olfactory perception and communication, and hence they are of utmost importance for developing repellents or pesticides. Hence, accurate gene prediction of insect ORs from newly sequenced genomes is an important but challenging task. We have developed a dedicated web-server, ‘insectOR’, to predict and validate insect OR genes using multiple gene prediction algorithms, accompanied by relevant validations. It is possible to employ this sever nearly automatically and perform rapid prediction of the OR gene loci from thousands of OR-protein-to-genome alignments, resolve gene boundaries for tandem OR genes and refine them further to provide more complete OR gene models. InsectOR outperformed the popular genome annotation pipelines (MAKER and NCBI eukaryotic genome annotation) in terms of overall sensitivity at base, exon and locus level, when tested on two distantly related insect genomes. It displayed more than 95% nucleotide level precision in both tests. Finally, given the same input data and parameters, InsectOR missed less than 2% gene loci, in contrast to 55% loci missed by MAKER for Drosophila melanogaster. The web-server is freely available on the web at http://caps.ncbs.res.in/insectOR/. All major browsers are supported. Website is implemented in Python with Jinja2 for templating and bootstrap framework which uses HTML, CSS and JavaScript/Ajax. The core pipeline is written in Perl.

Differential and overlapping expression patterns of X-dll3 and Pax-6 genes suggest distinct roles in olfactory system development of the African clawed frog Xenopus laevis

2001 ◽  
Vol 204 (12) ◽  
pp. 2049-2061 ◽  
Author(s):  
Marie-Dominique Franco ◽  
Michael P. Pape ◽  
Jennifer J. Swiergiel ◽  
Gail D. Burd
Keyword(s):  
Xenopus Laevis ◽  
Expression Pattern ◽  
Olfactory Epithelium ◽  
Olfactory System ◽  
De Novo ◽  
System Development ◽  
Expression Patterns ◽  
Basal Cells ◽  
Olfactory Placode ◽  
Water Borne

SUMMARY In Xenopus laevis, the formation of the adult olfactory epithelium involves embryonic, larval and metamorphic phases. The olfactory epithelium in the principal cavity (PC) develops during embryogenesis from the olfactory placode and is thought to respond to water-borne odorants throughout larval life. During metamorphosis, the PC undergoes major transformations and is exposed to air-borne odorants. Also during metamorphosis, the middle cavity (MC) develops de novo. The olfactory epithelium in the MC has the same characteristics as that in the larval PC and is thought to respond to water-borne odorants. Using in situ hybridization, we analyzed the expression pattern of the homeobox genes X-dll3 and Pax-6 within the developing olfactory system. Early in development, X-dll3 is expressed in both the neuronal and non-neuronal ectoderm of the sense plate and in all cell layers of the olfactory placode and larval PC. Expression becomes restricted to the neurons and basal cells of the PC by mid-metamorphosis. During metamorphosis, X-dll3 is also expressed throughout the developing MC epithelium and becomes restricted to neurons and basal cells at metamorphic climax. This expression pattern suggests that X-dll3 is first involved in the patterning and genesis of all cells forming the olfactory tissue and is then involved in neurogenesis or neuronal maturation in putative water- and air-sensing epithelia. In contrast, Pax-6 expression is restricted to the olfactory placode, larval PC and metamorphic MC, suggesting that Pax-6 is specifically involved in the formation of water-sensing epithelium. The expression patterns suggest that X-dll3 and Pax-6 are both involved in establishing the olfactory placode during embryonic development, but subtle differences in cellular and temporal expression patterns suggest that these genes have distinct functions.

Single Cell Spike Activity in the Olfactory Bulb

1956 ◽  
Vol 186 (2) ◽  
pp. 255-257 ◽  
Author(s):  
Raymond R. Walsh
Keyword(s):  
Olfactory Bulb ◽  
Single Cell ◽  
Spike Activity ◽  
Olfactory System ◽  
Olfactory Receptors ◽  
Class I ◽  
Olfactory Stimulation ◽  
Fundamental Characteristic ◽  
Class Iii ◽  
Discharge Patterns

Studies of single-cell spike discharges in the olfactory bulb of the rabbit indicate the presence of three classes of neurons as characterized by their discharge patterns. Cells of class I discharge continuously and spontaneously; class II cells discharge intermittently in bursts, in synchrony with the passage of air through the nose. Cells of classes I and II are unmodified during olfactory stimulation. It appears there are many cells in the olfactory bulb whose discharge patterns are unrelated to excitation of the olfactory receptors by odors. Cells of class III respond to appropriate odors; the response of such cells to some odors and not others indicates that odor specificity is a fundamental characteristic of the olfactory system.

Olfactory epithelium ontogenesis and function in postembryonic North American Bullfrog (Rana (Lithobates) catesbeiana) tadpoles

2020 ◽  
Vol 98 (6) ◽  
pp. 367-375 ◽  
Author(s):  
J.L. Heerema ◽  
S.J. Bogart ◽  
C.C. Helbing ◽  
G.G. Pyle
Keyword(s):  
Olfactory Epithelium ◽  
North American ◽  
Olfactory System ◽  
Postembryonic Development ◽  
Acid Mixture ◽  
Epithelial Surface ◽  
American Bullfrog ◽  
Olfactory Stimuli ◽  
And Function ◽  
Lithobates Catesbeiana

During metamorphosis, the olfactory system remodelling in anuran tadpoles — to transition from detecting waterborne odorants to volatile odorants as frogs — is extensive. How the olfactory system transitions from the larval to frog form is poorly understood, particularly in species that become (semi-)terrestrial. We investigated the ontogeny and function of the olfactory epithelium of North American Bullfrog (Rana (Lithobates) catesbeiana Shaw, 1802) tadpoles at various stages of postembryonic development. Changes in sensory components observable at the epithelial surface were examined by scanning electron microscopy. Functionality of the developing epithelium was tested using a neurophysiological technique (electro-olfactography (EOG)), and behaviourally, using a choice maze to assess tadpole response to olfactory stimuli (algae extract, amino acids). The youngest (premetamorphic) tadpoles responded behaviourally to an amino acid mixture despite having underdeveloped olfactory structures (cilia, olfactory knobs) and no EOG response. The consistent appearance of olfactory structures in older (prometamorphic) tadpoles coincided with reliably obtaining EOG responses to olfactory stimuli. However, as tadpoles aged further, and despite indistinguishable differences in sensory components, behavioural- and EOG-based olfactory responses were drastically reduced, most strongly near metamorphic climax. This work demonstrates a more complex relationship between structure and function of the olfactory system during tadpole life history than originally thought.

scholarly journals The role of SNMPs in insect olfaction

2020 ◽  
Author(s):  
Sina Cassau ◽  
Jürgen Krieger
Keyword(s):  
Membrane Proteins ◽  
Olfactory System ◽  
Critical Role ◽  
Olfactory Receptors ◽  
Wide Distribution ◽  
Insect Olfaction ◽  
Survival And Reproduction ◽  
Odorant Binding ◽  
Encoding Genes

AbstractThe sense of smell enables insects to recognize olfactory signals crucial for survival and reproduction. In insects, odorant detection highly depends on the interplay of distinct proteins expressed by specialized olfactory sensory neurons (OSNs) and associated support cells which are housed together in chemosensory units, named sensilla, mainly located on the antenna. Besides odorant-binding proteins (OBPs) and olfactory receptors, so-called sensory neuron membrane proteins (SNMPs) are indicated to play a critical role in the detection of certain odorants. SNMPs are insect-specific membrane proteins initially identified in pheromone-sensitive OSNs of Lepidoptera and are indispensable for a proper detection of pheromones. In the last decades, genome and transcriptome analyses have revealed a wide distribution of SNMP-encoding genes in holometabolous and hemimetabolous insects, with a given species expressing multiple subtypes in distinct cells of the olfactory system. Besides SNMPs having a neuronal expression in subpopulations of OSNs, certain SNMP types were found expressed in OSN-associated support cells suggesting different decisive roles of SNMPs in the peripheral olfactory system. In this review, we will report the state of knowledge of neuronal and non-neuronal members of the SNMP family and discuss their possible functions in insect olfaction.

Sign in / Sign up

Export Citation Format

Share Document