WorldWideScience

Sample records for vertebrate olfactory receptor

  1. Role of a Ubiquitously Expressed Receptor in the Vertebrate Olfactory System

    OpenAIRE

    DeMaria, Shannon; Berke, Allison P.; Van Name, Eric; Heravian, Anisa; Ferreira, Todd; Ngai, John

    2013-01-01

    Odorant cues are recognized by receptors expressed on olfactory sensory neurons, the primary sensory neurons of the olfactory epithelium. Odorant receptors typically obey the “one receptor, one neuron” rule, in which the receptive field of the olfactory neuron is determined by the singular odorant receptor that it expresses. Odor-evoked receptor activity across the population of olfactory neurons is then interpreted by the brain to identify the molecular nature of the odorant stimulus. In the...

  2. Role of a Ubiquitously Expressed Receptor in the Vertebrate Olfactory System

    Science.gov (United States)

    DeMaria, Shannon; Berke, Allison P.; Van Name, Eric; Heravian, Anisa; Ferreira, Todd

    2013-01-01

    Odorant cues are recognized by receptors expressed on olfactory sensory neurons, the primary sensory neurons of the olfactory epithelium. Odorant receptors typically obey the “one receptor, one neuron” rule, in which the receptive field of the olfactory neuron is determined by the singular odorant receptor that it expresses. Odor-evoked receptor activity across the population of olfactory neurons is then interpreted by the brain to identify the molecular nature of the odorant stimulus. In the present study, we characterized the properties of a C family G-protein-coupled receptor that, unlike most other odorant receptors, is expressed in a large population of microvillous sensory neurons in the zebrafish olfactory epithelium and the mouse vomeronasal organ. We found that this receptor, OlfCc1 in zebrafish and its murine ortholog Vmn2r1, is a calcium-dependent, low-sensitivity receptor specific for the hydrophobic amino acids isoleucine, leucine, and valine. Loss-of-function experiments in zebrafish embryos demonstrate that OlfCc1 is required for olfactory responses to a diverse mixture of polar, nonpolar, acidic, and basic amino acids. OlfCc1 was also found to promote localization of other OlfC receptor family members to the plasma membrane in heterologous cells. Together, these results suggest that the broadly expressed OlfCc1 is required for amino acid detection by the olfactory system and suggest that it plays a role in the function and/or intracellular trafficking of other olfactory and vomeronasal receptors with which it is coexpressed. PMID:24048853

  3. Ionotropic crustacean olfactory receptors.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Corey

    Full Text Available The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs, the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs, as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

  4. The olfactory receptor gene repertoires in secondary-adapted marine vertebrates: evidence for reduction of the functional proportions in cetaceans

    OpenAIRE

    Kishida, Takushi; Kubota, Shin; Shirayama, Yoshihisa; Fukami, Hironobu

    2007-01-01

    An olfactory receptor (OR) multigene family is responsible for the well-developed sense of smell possessed by terrestrial tetrapods. Mammalian OR genes had diverged greatly in the terrestrial environment after the fish–tetrapod split, indicating their importance to land habitation. In this study, we analysed OR genes of marine tetrapods (minke whale Balaenoptera acutorostrata, dwarf sperm whale Kogia sima, Dall's porpoise Phocoenoides dalli, Steller's sea lion Eumetopias jubatus and loggerhea...

  5. Olfactory Receptor Database: a sensory chemoreceptor resource

    OpenAIRE

    Skoufos, Emmanouil; Marenco, Luis; Nadkarni, Prakash M.; Miller, Perry L.; Shepherd, Gordon M.

    2000-01-01

    The Olfactory Receptor Database (ORDB) is a WWW-accessible database that has been expanded from an olfactory receptor resource to a chemoreceptor resource. It stores data on six classes of G-protein-coupled sensory chemoreceptors: (i) olfactory receptor-like proteins, (ii) vomeronasal receptors, (iii) insect olfactory receptors, (iv) worm chemoreceptors, (v) taste papilla receptors and (vi) fungal pheromone receptors. A complementary database of the ligands of these receptors (OdorDB) has bee...

  6. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

    Giorgi, Franco; Maggio, Roberto; Bruni, Luis Emilio

    2011-01-01

    environmental conditions. By adopting this standpoint, the functional attribution as olfactory or chemotactic sensors to these receptors should not be seen neither as a cause conditioning receptor gene expression, nor as a final effect resulting from genetically predetermined programs, but as a direct...... and odor-decoding processes. However, this type of explanation does not entirely justify the role olfactory receptors have played during evolution, since they are also expressed ectopically in different organs and/or tissues. Homologous olfactory genes have in fact been found in such diverse cells and....../or organs as spermatozoa, testis and kidney where they are assumed to act as chemotactic sensors or renin modulators. To justify their functional diversity, homologous olfactory receptors are assumed to share the same basic role: that of conferring a self-identity to cells or tissues under varying...

  7. Melatonin Receptor Genes in Vertebrates

    Directory of Open Access Journals (Sweden)

    Hua Dong Yin

    2013-05-01

    Full Text Available Melatonin receptors are members of the G protein-coupled receptor (GPCR family. Three genes for melatonin receptors have been cloned. The MT1 (or Mel1a or MTNR1A and MT2 (or Mel1b or MTNR1B receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype, Mel1c (or MTNR1C, has been identified in fish, amphibians and birds. Another melatonin related orphan receptor, GPR50, which does not bind melatonin, is found exclusively in mammals. The hormone melatonin is secreted primarily by the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone acts systemically in numerous organs. In the brain, it is involved in the regulation of various neural and endocrine processes, and it readjusts the circadian pacemaker, the suprachiasmatic nucleus. This article reviews recent studies of gene organization, expression, evolution and mutations of melatonin receptor genes of vertebrates. Gene polymorphisms reveal that numerous mutations are associated with diseases and disorders. The phylogenetic analysis of receptor genes indicates that GPR50 is an outgroup to all other melatonin receptor sequences. GPR50 may have separated from a melatonin receptor ancestor before the split between MTNR1C and the MTNR1A/B ancestor.

  8. Olfactory receptors in non-chemosensory tissues

    Directory of Open Access Journals (Sweden)

    NaNa Kang & JaeHyung Koo*

    2012-11-01

    Full Text Available Olfactory receptors (ORs detect volatile chemicals that lead tothe initial perception of smell in the brain. The olfactory receptor(OR is the first protein that recognizes odorants in theolfactory signal pathway and it is present in over 1,000 genesin mice. It is also the largest member of the G protein-coupledreceptors (GPCRs. Most ORs are extensively expressed in thenasal olfactory epithelium where they perform the appropriatephysiological functions that fit their location. However, recentwhole-genome sequencing shows that ORs have been foundoutside of the olfactory system, suggesting that ORs may playan important role in the ectopic expression of non-chemosensorytissues. The ectopic expressions of ORs and their physiologicalfunctions have attracted more attention recently sinceMOR23 and testicular hOR17-4 have been found to be involvedin skeletal muscle development, regeneration, and humansperm chemotaxis, respectively. When identifying additionalexpression profiles and functions of ORs in non-olfactorytissues, there are limitations posed by the small number ofantibodies available for similar OR genes. This review presentsthe results of a research series that identifies ectopic expressionsand functions of ORs in non-chemosensory tissues toprovide insight into future research directions.

  9. Evolution of endothelin receptors in vertebrates.

    Science.gov (United States)

    Braasch, Ingo; Schartl, Manfred

    2014-12-01

    Endothelin receptors are G protein coupled receptors (GPCRs) of the β-group of rhodopsin receptors that bind to endothelin ligands, which are 21 amino acid long peptides derived from longer prepro-endothelin precursors. The most basal Ednr-like GPCR is found outside vertebrates in the cephalochordate amphioxus, but endothelin ligands are only present among vertebrates, including the lineages of jawless vertebrates (lampreys and hagfishes), cartilaginous vertebrates (sharks, rays, and chimaeras), and bony vertebrates (ray-finned fishes and lobe-finned vertebrates including tetrapods). A bona fide endothelin system is thus a vertebrate-specific innovation with important roles for regulating the cardiovascular system, renal and pulmonary processes, as well as for the development of the vertebrate-specific neural crest cell population and its derivatives. Expectedly, dysregulation of endothelin receptors and the endothelin system leads to a multitude of human diseases. Despite the importance of different types of endothelin receptors for vertebrate development and physiology, current knowledge on endothelin ligand-receptor interactions, on the expression of endothelin receptors and their ligands, and on the functional roles of the endothelin system for embryonic development and in adult vertebrates is very much biased towards amniote vertebrates. Recent analyses from a variety of vertebrate lineages, however, have shown that the endothelin system in lineages such as teleost fish and lampreys is more diverse and is divergent from the mammalian endothelin system. This diversity is mainly based on differential evolution of numerous endothelin system components among vertebrate lineages generated by two rounds of whole genome duplication (three in teleosts) during vertebrate evolution. Here we review current understanding of the evolutionary history of the endothelin receptor family in vertebrates supplemented with surveys on the endothelin receptor gene complement of

  10. Genetic diversity of canine olfactory receptors

    Directory of Open Access Journals (Sweden)

    Hitte Christophe

    2009-01-01

    Full Text Available Abstract Background Evolution has resulted in large repertoires of olfactory receptor (OR genes, forming the largest gene families in mammalian genomes. Knowledge of the genetic diversity of olfactory receptors is essential if we are to understand the differences in olfactory sensory capability between individuals. Canine breeds constitute an attractive model system for such investigations. Results We sequenced 109 OR genes considered representative of the whole OR canine repertoire, which consists of more than 800 genes, in a cohort of 48 dogs of six different breeds. SNP frequency showed the overall level of polymorphism to be high. However, the distribution of SNP was highly heterogeneous among OR genes. More than 50% of OR genes were found to harbour a large number of SNP, whereas the rest were devoid of SNP or only slightly polymorphic. Heterogeneity was also observed across breeds, with 25% of the SNP breed-specific. Linkage disequilibrium within OR genes and OR clusters suggested a gene conversion process, consistent with a mean level of polymorphism higher than that observed for introns and intergenic sequences. A large proportion (47% of SNP induced amino-acid changes and the Ka/Ks ratio calculated for all alleles with a complete ORF indicated a low selective constraint with respect to the high level of redundancy of the olfactory combinatory code and an ongoing pseudogenisation process, which affects dog breeds differently. Conclusion Our demonstration of a high overall level of polymorphism, likely to modify the ligand-binding capacity of receptors distributed differently within the six breeds tested, is the first step towards understanding why Labrador Retrievers and German Shepherd Dogs have a much greater potential for use as sniffer dogs than Pekingese dogs or Greyhounds. Furthermore, the heterogeneity in OR polymorphism observed raises questions as to why, in a context in which most OR genes are highly polymorphic, a subset of

  11. Nested Expression Domains for Odorant Receptors in Zebrafish Olfactory Epithelium

    Science.gov (United States)

    Weth, Franco; Nadler, Walter; Korsching, Sigrun

    1996-11-01

    The mapping of high-dimensional olfactory stimuli onto the two-dimensional surface of the nasal sensory epithelium constitutes the first step in the neuronal encoding of olfactory input. We have used zebrafish as a model system to analyze the spatial distribution of odorant receptor molecules in the olfactory epithelium by quantitative in situ hybridization. To this end, we have cloned 10 very divergent zebrafish odorant receptor molecules by PCR. Individual genes are expressed in sparse olfactory receptor neurons. Analysis of the position of labeled cells in a simplified coordinate system revealed three concentric, albeit overlapping, expression domains for the four odorant receptors analyzed in detail. Such regionalized expression should result in a corresponding segregation of functional response properties. This might represent the first step of spatial encoding of olfactory input or be essential for the development of the olfactory system.

  12. Oligomerisation of C. elegans Olfactory Receptors, ODR-10 and STR-112, in Yeast

    KAUST Repository

    Tehseen, Muhammad

    2014-09-25

    It is widely accepted that vertebrate G-Protein Coupled Receptors (GPCRs) associate with each other as homo- or hetero-dimers or higher-order oligomers. The C. elegans genome encodes hundreds of olfactory GPCRs, which may be expressed in fewer than a dozen chemosensory neurons, suggesting an opportunity for oligomerisation. Here we show, using three independent lines of evidence: co-immunoprecipitation, bioluminescence resonance energy transfer and a yeast two-hybrid assay that nematode olfactory receptors (ORs) oligomerise when heterologously expressed in yeast. Specifically, the nematode receptor ODR-10 is able to homo-oligomerise and can also form heteromers with the related nematode receptor STR-112. ODR-10 also oligomerised with the rat I7 OR but did not oligomerise with the human somatostatin receptor 5, a neuropeptide receptor. In this study, the question of functional relevance was not addressed and remains to be investigated.

  13. Oligomerisation of C. elegans Olfactory Receptors, ODR-10 and STR-112, in Yeast

    KAUST Repository

    Tehseen, Muhammad; Liao, Chunyan; Dacres, Helen; Dumancic, Mira; Trowell, Stephen; Anderson, Alisha

    2014-01-01

    It is widely accepted that vertebrate G-Protein Coupled Receptors (GPCRs) associate with each other as homo- or hetero-dimers or higher-order oligomers. The C. elegans genome encodes hundreds of olfactory GPCRs, which may be expressed in fewer than a dozen chemosensory neurons, suggesting an opportunity for oligomerisation. Here we show, using three independent lines of evidence: co-immunoprecipitation, bioluminescence resonance energy transfer and a yeast two-hybrid assay that nematode olfactory receptors (ORs) oligomerise when heterologously expressed in yeast. Specifically, the nematode receptor ODR-10 is able to homo-oligomerise and can also form heteromers with the related nematode receptor STR-112. ODR-10 also oligomerised with the rat I7 OR but did not oligomerise with the human somatostatin receptor 5, a neuropeptide receptor. In this study, the question of functional relevance was not addressed and remains to be investigated.

  14. Expressing exogenous functional odorant receptors in cultured olfactory sensory neurons

    Directory of Open Access Journals (Sweden)

    Fomina Alla F

    2008-09-01

    Full Text Available Abstract Background Olfactory discrimination depends on the large numbers of odorant receptor genes and differential ligand-receptor signaling among neurons expressing different receptors. In this study, we describe an in vitro system that enables the expression of exogenous odorant receptors in cultured olfactory sensory neurons. Olfactory sensory neurons in the culture express characteristic signaling molecules and, therefore, provide a system to study receptor function within its intrinsic cellular environment. Results We demonstrate that cultured olfactory sensory neurons express endogenous odorant receptors. Lentiviral vector-mediated gene transfer enables successful ectopic expression of odorant receptors. We show that the ectopically expressed mouse I7 is functional in the cultured olfactory sensory neurons. When two different odorant receptors are ectopically expressed simultaneously, both receptor proteins co-localized in the same olfactory sensory neurons up to 10 days in vitro. Conclusion This culture technique provided an efficient method to culture olfactory sensory neurons whose morphology, molecular characteristics and maturation progression resembled those observed in vivo. Using this system, regulation of odorant receptor expression and its ligand specificity can be studied in its intrinsic cellular environment.

  15. Odor memories regulate olfactory receptor expression in the sensory periphery.

    Science.gov (United States)

    Claudianos, Charles; Lim, Julianne; Young, Melanie; Yan, Shanzhi; Cristino, Alexandre S; Newcomb, Richard D; Gunasekaran, Nivetha; Reinhard, Judith

    2014-05-01

    Odor learning induces structural and functional modifications throughout the olfactory system, but it is currently unknown whether this plasticity extends to the olfactory receptors (Or) in the sensory periphery. Here, we demonstrate that odor learning induces plasticity in olfactory receptor expression in the honeybee, Apis mellifera. Using quantitative RT-PCR analysis, we show that six putative floral scent receptors were differentially expressed in the bee antennae depending on the scent environment that the bees experienced. Or151, which we characterized using an in vitro cell expression system as a broadly tuned receptor binding floral odorants such as linalool, and Or11, the specific receptor for the queen pheromone 9-oxo-decenoic acid, were significantly down-regulated after honeybees were conditioned with the respective odorants in an olfactory learning paradigm. Electroantennogram recordings showed that the neural response of the antenna was similarly reduced after odor learning. Long-term odor memory was essential for inducing these changes, suggesting that the molecular mechanisms involved in olfactory memory also regulate olfactory receptor expression. Our study demonstrates for the first time that olfactory receptor expression is experience-dependent and modulated by scent conditioning, providing novel insight into how molecular regulation at the periphery contributes to plasticity in the olfactory system. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Specific olfactory receptor populations projecting to identified glomeruli in the rat olfactory bulb.

    Science.gov (United States)

    Jastreboff, P J; Pedersen, P E; Greer, C A; Stewart, W B; Kauer, J S; Benson, T E; Shepherd, G M

    1984-08-01

    A critical gap exists in our knowledge of the topographical relationship between the olfactory epithelium and olfactory bulb. The present report describes the application to this problem of a method involving horseradish peroxidase conjugated to wheat germ agglutinin. This material was iontophoretically delivered to circumscribed glomeruli in the olfactory bulb and the characteristics and distribution of retrogradely labeled receptor cells were assessed. After discrete injections into small glomerular groups in the caudomedial bulb, topographically defined populations of receptor cells were labeled. Labeled receptor cell somata appeared at several levels within the epithelium. The receptor cell apical dendrites followed a tight helical course towards the surface of the epithelium. The data thus far demonstrate that functional units within the olfactory system may include not only glomeruli as previously suggested but, in addition, a corresponding matrix of receptor cells possessing functional and topographical specificity.

  17. The repertoire of olfactory C family G protein-coupled receptors in zebrafish: candidate chemosensory receptors for amino acids

    Directory of Open Access Journals (Sweden)

    Ngai John

    2006-12-01

    Full Text Available Abstract Background Vertebrate odorant receptors comprise at least three types of G protein-coupled receptors (GPCRs: the OR, V1R, and V2R/V2R-like receptors, the latter group belonging to the C family of GPCRs. These receptor families are thought to receive chemosensory information from a wide spectrum of odorant and pheromonal cues that influence critical animal behaviors such as feeding, reproduction and other social interactions. Results Using genome database mining and other informatics approaches, we identified and characterized the repertoire of 54 intact "V2R-like" olfactory C family GPCRs in the zebrafish. Phylogenetic analysis – which also included a set of 34 C family GPCRs from fugu – places the fish olfactory receptors in three major groups, which are related to but clearly distinct from other C family GPCRs, including the calcium sensing receptor, metabotropic glutamate receptors, GABA-B receptor, T1R taste receptors, and the major group of V2R vomeronasal receptor families. Interestingly, an analysis of sequence conservation and selective pressure in the zebrafish receptors revealed the retention of a conserved sequence motif previously shown to be required for ligand binding in other amino acid receptors. Conclusion Based on our findings, we propose that the repertoire of zebrafish olfactory C family GPCRs has evolved to allow the detection and discrimination of a spectrum of amino acid and/or amino acid-based compounds, which are potent olfactory cues in fish. Furthermore, as the major groups of fish receptors and mammalian V2R receptors appear to have diverged significantly from a common ancestral gene(s, these receptors likely mediate chemosensation of different classes of chemical structures by their respective organisms.

  18. Widespread ectopic expression of olfactory receptor genes

    Directory of Open Access Journals (Sweden)

    Yanai Itai

    2006-05-01

    Full Text Available Abstract Background Olfactory receptors (ORs are the largest gene family in the human genome. Although they are expected to be expressed specifically in olfactory tissues, some ectopic expression has been reported, with special emphasis on sperm and testis. The present study systematically explores the expression patterns of OR genes in a large number of tissues and assesses the potential functional implication of such ectopic expression. Results We analyzed the expression of hundreds of human and mouse OR transcripts, via EST and microarray data, in several dozens of human and mouse tissues. Different tissues had specific, relatively small OR gene subsets which had particularly high expression levels. In testis, average expression was not particularly high, and very few highly expressed genes were found, none corresponding to ORs previously implicated in sperm chemotaxis. Higher expression levels were more common for genes with a non-OR genomic neighbor. Importantly, no correlation in expression levels was detected for human-mouse orthologous pairs. Also, no significant difference in expression levels was seen between intact and pseudogenized ORs, except for the pseudogenes of subfamily 7E which has undergone a human-specific expansion. Conclusion The OR superfamily as a whole, show widespread, locus-dependent and heterogeneous expression, in agreement with a neutral or near neutral evolutionary model for transcription control. These results cannot reject the possibility that small OR subsets might play functional roles in different tissues, however considerable care should be exerted when offering a functional interpretation for ectopic OR expression based only on transcription information.

  19. Olfactory sensations produced by high-energy photon irradiation of the olfactory receptor mucosa in humans

    International Nuclear Information System (INIS)

    Sagar, S.M.; Thomas, R.J.; Loverock, L.T.; Spittle, M.F.

    1991-01-01

    During irradiation of volumes that incorporate the olfactory system, a proportion of patients have complained of a pungent smell. A retrospective study was carried out to determine the prevalence of this side-effect. A questionnaire was sent to 40 patients whose treatment volumes included the olfactory region and also to a control group treated away from this region. The irradiated tumor volumes included the frontal lobe, whole brain, nasopharynx, pituitary fossa, and maxillary antrum. Of the 25 patients who replied, 60% experienced odorous symptoms during irradiation. They described the odor as unpleasant and consistent with ozone. Stimulation of olfactory receptors is considered to be caused by the radiochemical formation of ozone and free radicals in the mucus overlying the olfactory mucosa

  20. Integrated olfactory receptor and microarray gene expression databases

    Directory of Open Access Journals (Sweden)

    Crasto Chiquito J

    2007-06-01

    Full Text Available Abstract Background Gene expression patterns of olfactory receptors (ORs are an important component of the signal encoding mechanism in the olfactory system since they determine the interactions between odorant ligands and sensory neurons. We have developed the Olfactory Receptor Microarray Database (ORMD to house OR gene expression data. ORMD is integrated with the Olfactory Receptor Database (ORDB, which is a key repository of OR gene information. Both databases aim to aid experimental research related to olfaction. Description ORMD is a Web-accessible database that provides a secure data repository for OR microarray experiments. It contains both publicly available and private data; accessing the latter requires authenticated login. The ORMD is designed to allow users to not only deposit gene expression data but also manage their projects/experiments. For example, contributors can choose whether to make their datasets public. For each experiment, users can download the raw data files and view and export the gene expression data. For each OR gene being probed in a microarray experiment, a hyperlink to that gene in ORDB provides access to genomic and proteomic information related to the corresponding olfactory receptor. Individual ORs archived in ORDB are also linked to ORMD, allowing users access to the related microarray gene expression data. Conclusion ORMD serves as a data repository and project management system. It facilitates the study of microarray experiments of gene expression in the olfactory system. In conjunction with ORDB, ORMD integrates gene expression data with the genomic and functional data of ORs, and is thus a useful resource for both olfactory researchers and the public.

  1. Blocking muscarinic receptors in the olfactory bulb impairs performance on an olfactory short term memory task

    Directory of Open Access Journals (Sweden)

    Sasha eDevore

    2012-09-01

    Full Text Available Cholinergic inputs to cortical processing networks have long been associated with attentional and top-down processing. Experimental and theoretical studies suggest that cholinergic inputs to the main olfactory bulb (OB can modulate both neural and behavioral odor discrimination. Previous experiments from our laboratory and others demonstrate that blockade of nicotinic receptors directly impairs olfactory discrimination, whereas blockade of muscarinic receptors only measurably impairs olfactory perception when task demands are made more challenging, such as when very low-concentration odors are used or rats are required to maintain sensory memory over long durations. To further investigate the role of muscarinic signaling in the OB, we developed an olfactory delayed match-to-sample task using a digging-based behavioral paradigm. We find that rats are able to maintain robust short-term odor memory for tens to hundreds of seconds. To investigate the role of muscarinic signaling in task performance, we bilaterally infused scopolamine into the OB. We find that high dosages of scopolamine (38 mM impair performance on the task across all delays tested, including the baseline condition with no delay, whereas lower dosages (7.6 mM and 22.8 mM had no measureable effects. These results indicate that general execution of the match-to-sample task, even with no delay, is at least partially dependent on muscarinic signaling in the OB.

  2. Genetic basis of olfactory cognition: extremely high level of DNA sequence polymorphism in promoter regions of the human olfactory receptor genes revealed using the 1000 Genomes Project dataset.

    Science.gov (United States)

    Ignatieva, Elena V; Levitsky, Victor G; Yudin, Nikolay S; Moshkin, Mikhail P; Kolchanov, Nikolay A

    2014-01-01

    The molecular mechanism of olfactory cognition is very complicated. Olfactory cognition is initiated by olfactory receptor proteins (odorant receptors), which are activated by olfactory stimuli (ligands). Olfactory receptors are the initial player in the signal transduction cascade producing a nerve impulse, which is transmitted to the brain. The sensitivity to a particular ligand depends on the expression level of multiple proteins involved in the process of olfactory cognition: olfactory receptor proteins, proteins that participate in signal transduction cascade, etc. The expression level of each gene is controlled by its regulatory regions, and especially, by the promoter [a region of DNA about 100-1000 base pairs long located upstream of the transcription start site (TSS)]. We analyzed single nucleotide polymorphisms using human whole-genome data from the 1000 Genomes Project and revealed an extremely high level of single nucleotide polymorphisms in promoter regions of olfactory receptor genes and HLA genes. We hypothesized that the high level of polymorphisms in olfactory receptor promoters was responsible for the diversity in regulatory mechanisms controlling the expression levels of olfactory receptor proteins. Such diversity of regulatory mechanisms may cause the great variability of olfactory cognition of numerous environmental olfactory stimuli perceived by human beings (air pollutants, human body odors, odors in culinary etc.). In turn, this variability may provide a wide range of emotional and behavioral reactions related to the vast variety of olfactory stimuli.

  3. Genetic basis of olfactory cognition: extremely high level of DNA sequence polymorphism in promoter regions of the human olfactory receptor genes revealed using the 1000 Genomes Project dataset

    Directory of Open Access Journals (Sweden)

    Elena V. Ignatieva

    2014-03-01

    Full Text Available The molecular mechanism of olfactory cognition is very complicated. Olfactory cognition is initiated by olfactory receptor proteins (odorant receptors, which are activated by olfactory stimuli (ligands. Olfactory receptors are the initial player in the signal transduction cascade producing a nerve impulse, which is transmitted to the brain. The sensitivity to a particular ligand depends on the expression level of multiple proteins involved in the process of olfactory cognition: olfactory receptor proteins, proteins that participate in signal transduction cascade, etc. The expression level of each gene is controlled by its regulatory regions, and especially, by the promoter (a region of DNA about 100–1000 base pairs long located upstream of the transcription start site. We analyzed single nucleotide polymorphisms using human whole-genome data from the 1000 Genomes Project and revealed an extremely high level of single nucleotide polymorphisms in promoter regions of olfactory receptor genes and HLA genes. We hypothesized that the high level of polymorphisms in olfactory receptor promoters was responsible for the diversity in regulatory mechanisms controlling the expression levels of olfactory receptor proteins. Such diversity of regulatory mechanisms may cause the great variability of olfactory cognition of numerous environmental olfactory stimuli perceived by human beings (air pollutants, human body odors, odors in culinary etc.. In turn, this variability may provide a wide range of emotional and behavioral reactions related to the vast variety of olfactory stimuli.

  4. Large-scale production and study of a synthetic G protein-coupled receptor: Human olfactory receptor 17-4

    OpenAIRE

    Cook, Brian L.; Steuerwald, Dirk; Kaiser, Liselotte; Graveland-Bikker, Johanna; Vanberghem, Melanie; Berke, Allison P.; Herlihy, Kara; Pick, Horst; Vogel, Horst; Zhang, Shuguang

    2009-01-01

    Although understanding of the olfactory system has progressed at the level of downstream receptor signaling and the wiring of olfactory neurons, the system remains poorly understood at the molecular level of the receptors and their interaction with and recognition of odorant ligands. The structure and functional mechanisms of these receptors still remain a tantalizing enigma, because numerous previous attempts at the large-scale production of functional olfactory receptors (ORs) have not been...

  5. Towards structural models of molecular recognition in olfactory receptors.

    Science.gov (United States)

    Afshar, M; Hubbard, R E; Demaille, J

    1998-02-01

    The G protein coupled receptors (GPCR) are an important class of proteins that act as signal transducers through the cytoplasmic membrane. Understanding the structure and activation mechanism of these proteins is crucial for understanding many different aspects of cellular signalling. The olfactory receptors correspond to the largest family of GPCRs. Very little is known about how the structures of the receptors govern the specificity of interaction which enables identification of particular odorant molecules. In this paper, we review recent developments in two areas of molecular modelling: methods for modelling the configuration of trans-membrane helices and methods for automatic docking of ligands into receptor structures. We then show how a subset of these methods can be combined to construct a model of a rat odorant receptor interacting with lyral for which experimental data are available. This modelling can help us make progress towards elucidating the specificity of interactions between receptors and odorant molecules.

  6. Olfactory Receptors in Non-Chemosensory Organs: The Nervous System in Health and Disease

    NARCIS (Netherlands)

    Ferrer, Isidro; Garcia-Esparcia, Paula; Carmona, Margarita; Carro, Eva; Aronica, Eleonora; Kovacs, Gabor G.; Grison, Alice; Gustincich, Stefano

    2016-01-01

    Olfactory receptors (ORs) and down-stream functional signaling molecules adenylyl cyclase 3 (AC3), olfactory G protein α subunit (Gαolf), OR transporters receptor transporter proteins 1 and 2 (RTP1 and RTP2), receptor expression enhancing protein 1 (REEP1), and UDP-glucuronosyltransferases (UGTs)

  7. Immobilization of olfactory receptors onto gold electrodes for electrical biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Casuso, Ignacio [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain)], E-mail: icasuso@pcb.ub.es; Pla-Roca, Mateu [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain); Gomila, Gabriel [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain)], E-mail: ggomila@pcb.ub.es; Samitier, Josep [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain); Minic, Jasmina; Persuy, Marie A.; Salesse, Roland; Pajot-Augy, Edith [INRA, Neurobiologie de l' Olfaction et de la Prise Alimentaire, Equipe Recepteurs et Communication Chimique, Domaine de Vilvert, Jouy en Josas Cedex (France)

    2008-07-01

    We investigate the immobilization of native nanovesicles containing functional olfactory receptors onto gold electrodes by means of atomic force microscopy in liquid. We show that nanovesicles can be adsorbed without disrupting them presenting sizes once immobilized ranging from 50 nm to 200 nm in diameter. The size of the nanovesicles shows no dependence on the electrode hydrophobicity being constant in a height/width ratio close to 1:3. Nevertheless, electrode hydrophobicity does affect the surface coverage, the surface coverage is five times higher in hydrophilic electrodes than on hydrophobic ones. Surface coverage is also affected by nanovesicles dimensions in suspension, the size homogenization to around 50 nm yields a further five fold increment in surface coverage achieving a coverage of about 50% close to the hard spheres jamming limit (54.7%). A single layer of nanovesicles is always formed with no particle overlap. Present results provide insights into the immobilization on electrodes of olfactory receptors for further olfactory electrical biosensor development.

  8. Beyond Modeling: All-Atom Olfactory Receptor Model Simulations

    Directory of Open Access Journals (Sweden)

    Peter C Lai

    2012-05-01

    Full Text Available Olfactory receptors (ORs are a type of GTP-binding protein-coupled receptor (GPCR. These receptors are responsible for mediating the sense of smell through their interaction with odor ligands. OR-odorant interactions marks the first step in the process that leads to olfaction. Computational studies on model OR structures can validate experimental functional studies as well as generate focused and novel hypotheses for further bench investigation by providing a view of these interactions at the molecular level. Here we have shown the specific advantages of simulating the dynamic environment that is associated with OR-odorant interactions. We present a rigorous methodology that ranges from the creation of a computationally-derived model of an olfactory receptor to simulating the interactions between an OR and an odorant molecule. Given the ubiquitous occurrence of GPCRs in the membranes of cells, we anticipate that our OR-developed methodology will serve as a model for the computational structural biology of all GPCRs.

  9. Molecular modeling of ligand-receptor interactions in the OR5 olfactory receptor.

    Science.gov (United States)

    Singer, M S; Shepherd, G M

    1994-06-02

    Olfactory receptors belong to the superfamily of seven transmembrane domain, G protein-coupled receptors. In order to begin analysis of mechanisms of receptor activation, a computer model of the OR5 olfactory receptor has been constructed and compared with other members of this superfamily. We have tested docking of the odor molecule lyral, which is known to activate the OR5 receptor. The results point to specific ligand-binding residues on helices III through VII that form a binding pocket in the receptor. Some of these residues occupy sequence positions identical to ligand-binding residues conserved among other superfamily members. The results provide new insights into possible molecular mechanisms of odor recognition and suggest hypotheses to guide future experimental studies using site-directed mutagenesis.

  10. The essence of appetite: Does olfactory receptor variation play a role?

    Science.gov (United States)

    Olfactory receptors are G-protein coupled chemoreceptors expressed on millions of olfactory sensory neurons within the nasal cavity. These receptors detect environmental odorants and signal the brain regarding the location of feed, potential mates, and the presence of possible threats (e.g., predato...

  11. Olfactory bulb glomerular NMDA receptors mediate olfactory nerve potentiation and odor preference learning in the neonate rat.

    Directory of Open Access Journals (Sweden)

    Rebecca Lethbridge

    Full Text Available Rat pup odor preference learning follows pairing of bulbar beta-adrenoceptor activation with olfactory input. We hypothesize that NMDA receptor (NMDAR-mediated olfactory input to mitral cells is enhanced during training, such that increased calcium facilitates and shapes the critical cAMP pattern. Here, we demonstrate, in vitro, that olfactory nerve stimulation, at sniffing frequencies, paired with beta-adrenoceptor activation, potentiates olfactory nerve-evoked mitral cell firing. This potentiation is blocked by a NMDAR antagonist and by increased inhibition. Glomerular disinhibition also induces NMDAR-sensitive potentiation. In vivo, in parallel, behavioral learning is prevented by glomerular infusion of an NMDAR antagonist or a GABA(A receptor agonist. A glomerular GABA(A receptor antagonist paired with odor can induce NMDAR-dependent learning. The NMDA GluN1 subunit is phosphorylated in odor-specific glomeruli within 5 min of training suggesting early activation, and enhanced calcium entry, during acquisition. The GluN1 subunit is down-regulated 3 h after learning; and at 24 h post-training the GluN2B subunit is down-regulated. These events may assist memory stability. Ex vivo experiments using bulbs from trained rat pups reveal an increase in the AMPA/NMDA EPSC ratio post-training, consistent with an increase in AMPA receptor insertion and/or the decrease in NMDAR subunits. These results support a model of a cAMP/NMDA interaction in generating rat pup odor preference learning.

  12. Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2012-02-01

    BACKGROUND: Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. RESULTS: Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. CONCLUSION: Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

  13. Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2011-08-22

    Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

  14. Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

    Directory of Open Access Journals (Sweden)

    Hatt Hanns

    2011-08-01

    Full Text Available Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

  15. Blocking muscarinic receptors in the olfactory bulb impairs performance on an olfactory short-term memory task.

    Science.gov (United States)

    Devore, Sasha; Manella, Laura C; Linster, Christiane

    2012-01-01

    Cholinergic inputs to cortical processing networks have long been associated with attentional and top-down processing. Experimental and theoretical studies suggest that cholinergic inputs to the main olfactory bulb (OB) can modulate both neural and behavioral odor discrimination. Previous experiments from our laboratory and others demonstrate that blockade of nicotinic receptors directly impairs olfactory discrimination, whereas blockade of muscarinic receptors only measurably impairs olfactory perception when task demands are made more challenging, such as when very low-concentration odors are used or rats are required to maintain sensory memory over long durations. To further investigate the role of muscarinic signaling in the OB, we developed an olfactory delayed match-to-sample task using a digging-based behavioral paradigm. We find that rats are able to maintain robust short-term odor memory for 10-100 s. To investigate the role of muscarinic signaling in task performance, we bilaterally infused scopolamine into the OB. We find that high dosages of scopolamine (38 mM) impair performance on the task across all delays tested, including the baseline condition with no delay, whereas lower dosages (7.6 mM and 22.8 mM) had no measureable effects. These results indicate that general execution of the match-to-sample task, even with no delay, is at least partially dependent on muscarinic signaling in the OB.

  16. Designer lipid-like peptides: a class of detergents for studying functional olfactory receptors using commercial cell-free systems.

    Science.gov (United States)

    Corin, Karolina; Baaske, Philipp; Ravel, Deepali B; Song, Junyao; Brown, Emily; Wang, Xiaoqiang; Wienken, Christoph J; Jerabek-Willemsen, Moran; Duhr, Stefan; Luo, Yuan; Braun, Dieter; Zhang, Shuguang

    2011-01-01

    A crucial bottleneck in membrane protein studies, particularly G-protein coupled receptors, is the notorious difficulty of finding an optimal detergent that can solubilize them and maintain their stability and function. Here we report rapid production of 12 unique mammalian olfactory receptors using short designer lipid-like peptides as detergents. The peptides were able to solubilize and stabilize each receptor. Circular dichroism showed that the purified olfactory receptors had alpha-helical secondary structures. Microscale thermophoresis suggested that the receptors were functional and bound their odorants. Blot intensity measurements indicated that milligram quantities of each olfactory receptor could be produced with at least one peptide detergent. The peptide detergents' capability was comparable to that of the detergent Brij-35. The ability of 10 peptide detergents to functionally solubilize 12 olfactory receptors demonstrates their usefulness as a new class of detergents for olfactory receptors, and possibly other G-protein coupled receptors and membrane proteins.

  17. Designer lipid-like peptides: a class of detergents for studying functional olfactory receptors using commercial cell-free systems.

    Directory of Open Access Journals (Sweden)

    Karolina Corin

    Full Text Available A crucial bottleneck in membrane protein studies, particularly G-protein coupled receptors, is the notorious difficulty of finding an optimal detergent that can solubilize them and maintain their stability and function. Here we report rapid production of 12 unique mammalian olfactory receptors using short designer lipid-like peptides as detergents. The peptides were able to solubilize and stabilize each receptor. Circular dichroism showed that the purified olfactory receptors had alpha-helical secondary structures. Microscale thermophoresis suggested that the receptors were functional and bound their odorants. Blot intensity measurements indicated that milligram quantities of each olfactory receptor could be produced with at least one peptide detergent. The peptide detergents' capability was comparable to that of the detergent Brij-35. The ability of 10 peptide detergents to functionally solubilize 12 olfactory receptors demonstrates their usefulness as a new class of detergents for olfactory receptors, and possibly other G-protein coupled receptors and membrane proteins.

  18. Changes in 5-HT4 receptor and 5-HT transporter binding in olfactory bulbectomized and glucocorticoid receptor heterozygous mice

    DEFF Research Database (Denmark)

    Licht, Cecilie L; Kirkegaard, Lisbeth; Zueger, Maha

    2010-01-01

    . The olfactory bulbectomized mice displayed increased activity in the open field test, a characteristic depression-like feature of this model. After bulbectomy, 5-HT(4) receptor binding was increased in the ventral hippocampus (12%) but unchanged in the dorsal hippocampus, frontal and caudal caudate putamen......]citalopram in two murine models of depression-related states, olfactory bulbectomy and glucocorticoid receptor heterozygous (GR(+/-)) mice. The olfactory bulbectomy model is characterized by 5-HT system changes, while the GR(+/-) mice have a deficit in hypothalamic-pituitary-adrenal (HPA) system control....... Among post hoc analyzed regions, there was a 14% decrease in 5-HT(4) receptor binding in the olfactory tubercles. The 5-HTT binding was unchanged in the hippocampus and caudate putamen of bulbectomized mice but post hoc analysis showed small decreases in lateral septum and lateral globus pallidus...

  19. CHARACTERIZATION OF THE OLFACTORY RECEPTORS EXPRESSED IN HUMAN SPERMATOZOA

    Directory of Open Access Journals (Sweden)

    Caroline eFlegel

    2016-01-01

    Full Text Available The detection of external cues is fundamental for human spermatozoa to locate the oocyte in the female reproductive tract. This task requires a specific chemoreceptor repertoire that is expressed on the surface of human spermatozoa, which is not fully identified to date. Olfactory receptors (ORs are candidate molecules and have been attributed to be involved in sperm chemotaxis and chemokinesis, indicating an important role in mammalian spermatozoa. An increasing importance has been suggested for spermatozoal RNA, which led us to investigate the expression of all 387 OR genes. This study provides the first comprehensive analysis of OR transcripts in human spermatozoa of several individuals by RNA-Seq. We detected 91 different transcripts in the spermatozoa samples that could be aligned to annotated OR genes. Using stranded mRNA-Seq, we detected a class of these putative OR transcripts in an antisense orientation, indicating a different function, rather than coding for a functional OR protein. Nevertheless, we were able to detect OR proteins in various compartments of human spermatozoa, indicating distinct functions in human sperm. A panel of various OR ligands induced Ca2+ signals in human spermatozoa, which could be inhibited by mibefradil. This study indicated that a variety of ORs are expressed at the mRNA and protein level in human spermatozoa and demonstrates that ORs are involved in the physiological processes.

  20. Peripheral-type benzodiazepine receptors in the central nervous system: localization to olfactory nerves.

    Science.gov (United States)

    Anholt, R R; Murphy, K M; Mack, G E; Snyder, S H

    1984-02-01

    Binding levels of [3H]Ro5-4864, a ligand selective for peripheral-type benzodiazepine receptors, are substantially higher in homogenates of the olfactory bulb than in the rest of the brain. Among peripheral tissues evaluated, high levels of [3H]Ro5-4864 binding are found in the nasal epithelium. Drug displacement studies show that these binding sites are pharmacologically of the peripheral type. Their presence in the nasal epithelium and in the olfactory bulb can be demonstrated in several different mammalian species. Autoradiographic studies of murine nose reveal a bipolar staining pattern around the cell bodies of the olfactory receptor cells, suggesting the presence of peripheral-type benzodiazepine receptors on both processes of these bipolar neurons. In the brain a high density of [3H]Ro5-4864 binding sites occurs in the nerve fiber and glomerular layers of the olfactory bulb. Throughout the rest of the brain [3H]Ro5-4864-associated silver grains are diffusely distributed with intense staining over the choroid plexus and along the ependymal linings of the ventricles. Both the distribution and the ontogenic development of the peripheral-type benzodiazepine receptors differ from the central-type receptors. Intranasal irrigation with 5% ZnSO4 results in a 50% reduction of peripheral-type benzodiazepine receptors in the olfactory bulb without affecting the density of central-type benzodiazepine receptors. Thus, [3H]Ro5-4864 binding sites in the olfactory bulb appear in large part to be localized to olfactory nerves which originate in the nasal epithelium.

  1. Expression Patterns of Odorant Receptors and Response Properties of Olfactory Sensory Neurons in Aged Mice

    OpenAIRE

    Lee, Anderson C.; Tian, Huikai; Grosmaitre, Xavier; Ma, Minghong

    2009-01-01

    The sense of smell deteriorates in normal aging, but the underling mechanisms are still elusive. Here we investigated age-related alterations in expression patterns of odorant receptor (OR) genes and functional properties of olfactory sensory neurons (OSNs)—2 critical factors that define the odor detection threshold in the olfactory epithelium. Using in situ hybridization for 9 representative OR genes, we compared the cell densities of each OR in coronal nose sections at different ages (3–27 ...

  2. Efficient cell-free production of olfactory receptors: detergent optimization, structure, and ligand binding analyses.

    Science.gov (United States)

    Kaiser, Liselotte; Graveland-Bikker, Johanna; Steuerwald, Dirk; Vanberghem, Mélanie; Herlihy, Kara; Zhang, Shuguang

    2008-10-14

    High-level production of membrane proteins, particularly of G protein-coupled receptors (GPCRs) in heterologous cell systems encounters a number of difficulties from their inherent hydrophobicity in their transmembrane domains, which frequently cause protein aggregation and cytotoxicity and thus reduce the protein yield. Recent advances in cell-free protein synthesis circumvent those problems to produce membrane proteins with a yield sometimes exceeding the cell-based approach. Here, we report cell-free production of a human olfactory receptor 17-4 (hOR17-4) using the wheat germ extract. Using the simple method, we also successful produced two additional olfactory receptors. To obtain soluble olfactory receptors and to increase yield, we directly added different detergents in varying concentrations to the cell-free reaction. To identify a purification buffer system that maintained the receptor in a nonaggregated form, we developed a method that uses small-volume size-exclusion column chromatography combined with rapid and sensitive dot-blot detection. Different buffer components including salt concentration, various detergents and detergent concentration, and reducing agent and its concentrations were evaluated for their ability to maintain the cell-free produced protein stable and nonaggregated. The purified olfactory receptor displays a typical a alpha-helical CD spectrum. Surface plasmon resonance measurements were used to show binding of a known ligand undecanal to hOR17-4. Our approach to produce a high yield of purified olfactory receptor is a milestone toward obtaining a large quantity of olfactory receptors for designing bionic sensors. Furthermore, this simple approach may be broadly useful not only for other classes of GPCRs but also for other membrane proteins.

  3. Drosophila olfactory receptors as classifiers for volatiles from disparate real world applications

    International Nuclear Information System (INIS)

    Nowotny, Thomas; De Bruyne, Marien; Warr, Coral G; Berna, Amalia Z; Trowell, Stephen C

    2014-01-01

    Olfactory receptors evolved to provide animals with ecologically and behaviourally relevant information. The resulting extreme sensitivity and discrimination has proven useful to humans, who have therefore co-opted some animals’ sense of smell. One aim of machine olfaction research is to replace the use of animal noses and one avenue of such research aims to incorporate olfactory receptors into artificial noses. Here, we investigate how well the olfactory receptors of the fruit fly, Drosophila melanogaster, perform in classifying volatile odourants that they would not normally encounter. We collected a large number of in vivo recordings from individual Drosophila olfactory receptor neurons in response to an ecologically relevant set of 36 chemicals related to wine (‘wine set’) and an ecologically irrelevant set of 35 chemicals related to chemical hazards (‘industrial set’), each chemical at a single concentration. Resampled response sets were used to classify the chemicals against all others within each set, using a standard linear support vector machine classifier and a wrapper approach. Drosophila receptors appear highly capable of distinguishing chemicals that they have not evolved to process. In contrast to previous work with metal oxide sensors, Drosophila receptors achieved the best recognition accuracy if the outputs of all 20 receptor types were used. (paper)

  4. Induction of an Olfactory Memory by the Activation of a Metabotropic Glutamate Receptor

    Science.gov (United States)

    Kaba, Hideto; Hayashi, Yasunori; Higuchi, Takashi; Nakanishi, Shigetada

    1994-07-01

    Female mice form an olfactory memory of male pheromones at mating; exposure to the pheromones of a strange male after that mating will block pregnancy. The formation of this memory is mediated by the accessory olfactory system, in which an increase in norepinephrine after mating reduces inhibitory transmission of γ-aminobutyric acid from the granule cells to the mitral cells. This study shows that the activation of mGluR2, a metabotropic glutamate receptor that suppresses the γ-aminobutyric acid inhibition of the mitral cells, permits the formation of a specific olfactory memory without the occurrence of mating by infusion of mGluR2 agonists into the female's accessory olfactory bulb. This memory faithfully reflects the memory formed at mating.

  5. Canine olfactory receptor gene polymorphism and its relation to odor detection performance by sniffer dogs.

    Science.gov (United States)

    Lesniak, Anna; Walczak, Marta; Jezierski, Tadeusz; Sacharczuk, Mariusz; Gawkowski, Maciej; Jaszczak, Kazimierz

    2008-01-01

    The outstanding sensitivity of the canine olfactory system has been acknowledged by using sniffer dogs in military and civilian service for detection of a variety of odors. It is hypothesized that the canine olfactory ability is determined by polymorphisms in olfactory receptor (OR) genes. We investigated 5 OR genes for polymorphic sites which might affect the olfactory ability of service dogs in different fields of specific substance detection. All investigated OR DNA sequences proved to have allelic variants, the majority of which lead to protein sequence alteration. Homozygous individuals at 2 gene loci significantly differed in their detection skills from other genotypes. This suggests a role of specific alleles in odor detection and a linkage between single-nucleotide polymorphism and odor recognition efficiency.

  6. Engineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivity

    OpenAIRE

    Berke, Allison Paige

    2013-01-01

    Abstract Engineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivityby Allison Paige Berke Joint Doctor of Philosophywith the University of California San FranciscoUniversity of California, Berkeley Professor Song Li, ChairDue to structural similarity, OlfCc1and its mammalian analogue V2R2 are hypothesized to respond to amino acid ligands in a calcium-mediated fashion. By analyzing receptor structure and making targeted mutations, the specificity and sensitivity of the receptor s...

  7. Transduction proteins of olfactory receptor cells: identification of guanine nucleotide binding proteins and protein kinase C

    International Nuclear Information System (INIS)

    Anholt, R.R.H.; Mumby, S.M.; Stoffers, D.A.; Girard, P.R.; Kuo, J.F.; Snyder, S.H.

    1987-01-01

    The authors have analyzed guanine nucleotide binding proteins (G-proteins) in the olfactory epithelium of Rana catesbeiana using subunit-specific antisera. The olfactory epithelium contained the α subunits of three G-proteins, migrating on polyacrylamide gels in SDS with apparent molecular weights of 45,000, 42,000, and 40,000, corresponding to G/sub s/, G/sub i/, and G/sub o/, respectively. A single β subunit with an apparent molecular weight of 36,000 was detected. An antiserum against the α subunit of retinal transducin failed to detect immunoreactive proteins in olfactory cilia detached from the epithelium. The olfactory cilia appeared to be enriched in immunoreactive G/sub sα/ relative to G/sub ichemical bond/ and G/sub ochemical bond/ when compared to membranes prepared from the olfactory epithelium after detachment of the cilia. Bound antibody was detected by autoradiography after incubation with [ 125 I]protein. Immunohistochemical studies using an antiserum against the β subunit of G-proteins revealed intense staining of the ciliary surface of the olfactory epithelium and of the axon bundles in the lamina propria. In contrast, an antiserum against a common sequence of the α subunits preferentially stained the cell membranes of the olfactory receptor cells and the acinar cells of Bowman's glands and the deep submucosal glands. In addition to G-proteins, they have identified protein kinase C in olfactory cilia via a protein kinase C specific antiserum and via phorbol ester binding. However, in contrast to the G-proteins, protein kinase C occurred also in cilia isolated from respiratory epithelium

  8. Evolution of the vertebrate insulin receptor substrate (Irs) gene family.

    Science.gov (United States)

    Al-Salam, Ahmad; Irwin, David M

    2017-06-23

    Insulin receptor substrate (Irs) proteins are essential for insulin signaling as they allow downstream effectors to dock with, and be activated by, the insulin receptor. A family of four Irs proteins have been identified in mice, however the gene for one of these, IRS3, has been pseudogenized in humans. While it is known that the Irs gene family originated in vertebrates, it is not known when it originated and which members are most closely related to each other. A better understanding of the evolution of Irs genes and proteins should provide insight into the regulation of metabolism by insulin. Multiple genes for Irs proteins were identified in a wide variety of vertebrate species. Phylogenetic and genomic neighborhood analyses indicate that this gene family originated very early in vertebrae evolution. Most Irs genes were duplicated and retained in fish after the fish-specific genome duplication. Irs genes have been lost of various lineages, including Irs3 in primates and birds and Irs1 in most fish. Irs3 and Irs4 experienced an episode of more rapid protein sequence evolution on the ancestral mammalian lineage. Comparisons of the conservation of the proteins sequences among Irs paralogs show that domains involved in binding to the plasma membrane and insulin receptors are most strongly conserved, while divergence has occurred in sequences involved in interacting with downstream effector proteins. The Irs gene family originated very early in vertebrate evolution, likely through genome duplications, and in parallel with duplications of other components of the insulin signaling pathway, including insulin and the insulin receptor. While the N-terminal sequences of these proteins are conserved among the paralogs, changes in the C-terminal sequences likely allowed changes in biological function.

  9. Neofunctionalization in vertebrates: the example of retinoic acid receptors.

    Directory of Open Access Journals (Sweden)

    Hector Escriva

    2006-07-01

    Full Text Available Understanding the role of gene duplications in establishing vertebrate innovations is one of the main challenges of Evo-Devo (evolution of development studies. Data on evolutionary changes in gene expression (i.e., evolution of transcription factor-cis-regulatory elements relationships tell only part of the story; protein function, best studied by biochemical and functional assays, can also change. In this study, we have investigated how gene duplication has affected both the expression and the ligand-binding specificity of retinoic acid receptors (RARs, which play a major role in chordate embryonic development. Mammals have three paralogous RAR genes--RAR alpha, beta, and gamma--which resulted from genome duplications at the origin of vertebrates. By using pharmacological ligands selective for specific paralogues, we have studied the ligand-binding capacities of RARs from diverse chordates species. We have found that RAR beta-like binding selectivity is a synapomorphy of all chordate RARs, including a reconstructed synthetic RAR representing the receptor present in the ancestor of chordates. Moreover, comparison of expression patterns of the cephalochordate amphioxus and the vertebrates suggests that, of all the RARs, RAR beta expression has remained most similar to that of the ancestral RAR. On the basis of these results together, we suggest that while RAR beta kept the ancestral RAR role, RAR alpha and RAR gamma diverged both in ligand-binding capacity and in expression patterns. We thus suggest that neofunctionalization occurred at both the expression and the functional levels to shape RAR roles during development in vertebrates.

  10. Changes in 5-HT4 receptor and 5-HT transporter binding in olfactory bulbectomized and glucocorticoid receptor heterozygous mice

    DEFF Research Database (Denmark)

    Licht, Cecilie Löe; Kirkegaard, Lisbeth; Zueger, Maha

    2010-01-01

    . The olfactory bulbectomized mice displayed increased activity in the open field test, a characteristic depression-like feature of this model. After bulbectomy, 5-HT(4) receptor binding was increased in the ventral hippocampus (12%) but unchanged in the dorsal hippocampus, frontal and caudal caudate putamen...

  11. CRDB: database of chemosensory receptor gene families in vertebrate.

    Directory of Open Access Journals (Sweden)

    Dong Dong

    Full Text Available Chemosensory receptors (CR are crucial for animals to sense the environmental changes and survive on earth. The emergence of whole-genome sequences provides us an opportunity to identify the entire CR gene repertoires. To completely gain more insight into the evolution of CR genes in vertebrates, we identified the nearly all CR genes in 25 vertebrates using homology-based approaches. Among these CR gene repertoires, nearly half of them were identified for the first time in those previously uncharacterized species, such as the guinea pig, giant panda and elephant, etc. Consistent with previous findings, we found that the numbers of CR genes vary extensively among different species, suggesting an extreme form of 'birth-and-death' evolution. For the purpose of facilitating CR gene analysis, we constructed a database with the goals to provide a resource for CR genes annotation and a web tool for exploring their evolutionary patterns. Besides a search engine for the gene extraction from a specific chromosome region, an easy-to-use phylogenetic analysis tool was also provided to facilitate online phylogeny study of CR genes. Our work can provide a rigorous platform for further study on the evolution of CR genes in vertebrates.

  12. Enhanced odor discrimination and impaired olfactory memory by spatially controlled switch of AMPA receptors.

    Directory of Open Access Journals (Sweden)

    Derya R Shimshek

    2005-11-01

    Full Text Available Genetic perturbations of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs are widely used to dissect molecular mechanisms of sensory coding, learning, and memory. In this study, we investigated the role of Ca2+-permeable AMPARs in olfactory behavior. AMPAR modification was obtained by depletion of the GluR-B subunit or expression of unedited GluR-B(Q, both leading to increased Ca2+ permeability of AMPARs. Mice with this functional AMPAR switch, specifically in forebrain, showed enhanced olfactory discrimination and more rapid learning in a go/no-go operant conditioning task. Olfactory memory, however, was dramatically impaired. GluR-B depletion in forebrain was ectopically variable ("mosaic" among individuals and strongly correlated with decreased olfactory memory in hippocampus and cortex. Accordingly, memory was rescued by transgenic GluR-B expression restricted to piriform cortex and hippocampus, while enhanced odor discrimination was independent of both GluR-B variability and transgenic GluR-B expression. Thus, correlated differences in behavior and levels of GluR-B expression allowed a mechanistic and spatial dissection of olfactory learning, discrimination, and memory capabilities.

  13. Enhanced odor discrimination and impaired olfactory memory by spatially controlled switch of AMPA receptors.

    Science.gov (United States)

    Shimshek, Derya R; Bus, Thorsten; Kim, Jinhyun; Mihaljevic, Andre; Mack, Volker; Seeburg, Peter H; Sprengel, Rolf; Schaefer, Andreas T

    2005-11-01

    Genetic perturbations of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs) are widely used to dissect molecular mechanisms of sensory coding, learning, and memory. In this study, we investigated the role of Ca2+-permeable AMPARs in olfactory behavior. AMPAR modification was obtained by depletion of the GluR-B subunit or expression of unedited GluR-B(Q), both leading to increased Ca2+ permeability of AMPARs. Mice with this functional AMPAR switch, specifically in forebrain, showed enhanced olfactory discrimination and more rapid learning in a go/no-go operant conditioning task. Olfactory memory, however, was dramatically impaired. GluR-B depletion in forebrain was ectopically variable ("mosaic") among individuals and strongly correlated with decreased olfactory memory in hippocampus and cortex. Accordingly, memory was rescued by transgenic GluR-B expression restricted to piriform cortex and hippocampus, while enhanced odor discrimination was independent of both GluR-B variability and transgenic GluR-B expression. Thus, correlated differences in behavior and levels of GluR-B expression allowed a mechanistic and spatial dissection of olfactory learning, discrimination, and memory capabilities.

  14. Molecular recognition of ketamine by a subset of olfactory G protein–coupled receptors

    Science.gov (United States)

    Saven, Jeffery G.; Matsunami, Hiroaki; Eckenhoff, Roderic G.

    2015-01-01

    Ketamine elicits various neuropharmacological effects, including sedation, analgesia, general anesthesia, and antidepressant activity. Through an in vitro screen, we identified four mouse olfactory receptors (ORs) that responded to ketamine. In addition to their presence in the olfactory epithelium, these G protein (heterotrimeric guanine nucleotide–binding protein)–coupled receptors (GPCRs) are distributed throughout the central nervous system. To better understand the molecular basis of the interactions between ketamine and ORs, we used sequence comparison and molecular modeling to design mutations that (i) increased, reduced, or abolished ketamine responsiveness in responding receptors, and (ii) rendered non-responding receptors responsive to ketamine. We showed that olfactory sensory neurons (OSNs) that expressed distinct ORs responded to ketamine in vivo, suggesting that ORs may serve as functional targets for ketamine. The ability to both abolish and introduce responsiveness to ketamine in GPCRs enabled us to identify and confirm distinct interaction loci in the binding site, which suggested a signature ketamine-binding pocket that may guide exploration of additional receptors for this general anesthetic drug. PMID:25829447

  15. Olfactory Receptors in Non-Chemosensory Organs: The Nervous System in Health and Disease.

    Science.gov (United States)

    Ferrer, Isidro; Garcia-Esparcia, Paula; Carmona, Margarita; Carro, Eva; Aronica, Eleonora; Kovacs, Gabor G; Grison, Alice; Gustincich, Stefano

    2016-01-01

    Olfactory receptors (ORs) and down-stream functional signaling molecules adenylyl cyclase 3 (AC3), olfactory G protein α subunit (Gαolf), OR transporters receptor transporter proteins 1 and 2 (RTP1 and RTP2), receptor expression enhancing protein 1 (REEP1), and UDP-glucuronosyltransferases (UGTs) are expressed in neurons of the human and murine central nervous system (CNS). In vitro studies have shown that these receptors react to external stimuli and therefore are equipped to be functional. However, ORs are not directly related to the detection of odors. Several molecules delivered from the blood, cerebrospinal fluid, neighboring local neurons and glial cells, distant cells through the extracellular space, and the cells' own self-regulating internal homeostasis can be postulated as possible ligands. Moreover, a single neuron outside the olfactory epithelium expresses more than one receptor, and the mechanism of transcriptional regulation may be different in olfactory epithelia and brain neurons. OR gene expression is altered in several neurodegenerative diseases including Parkinson's disease (PD), Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and sporadic Creutzfeldt-Jakob disease (sCJD) subtypes MM1 and VV2 with disease-, region- and subtype-specific patterns. Altered gene expression is also observed in the prefrontal cortex in schizophrenia with a major but not total influence of chlorpromazine treatment. Preliminary parallel observations have also shown the presence of taste receptors (TASRs), mainly of the bitter taste family, in the mammalian brain, whose function is not related to taste. TASRs in brain are also abnormally regulated in neurodegenerative diseases. These seminal observations point to the need for further studies on ORs and TASRs chemoreceptors in the mammalian brain.

  16. Serotonin receptor activity is necessary for olfactory learning and memory in Drosophila melanogaster.

    Science.gov (United States)

    Johnson, O; Becnel, J; Nichols, C D

    2011-09-29

    Learning and memory in the fruit fly, Drosophila melanogaster, is a complex behavior with many parallels to mammalian learning and memory. Although many neurotransmitters including acetylcholine, dopamine, glutamate, and GABA have previously been demonstrated to be involved in aversive olfactory learning and memory, the role of serotonin has not been well defined. Here, we present the first evidence of the involvement of individual serotonin receptors in olfactory learning and memory in the fly. We initially followed a pharmacological approach, utilizing serotonin receptor agonists and antagonists to demonstrate that all serotonin receptor families present in the fly are necessary for short-term learning and memory. Isobolographic analysis utilizing combinations of drugs revealed functional interactions are occurring between 5-HT(1A)-like and 5-HT(2), and 5-HT(2) and 5-HT(7) receptor circuits in mediating short-term learning and memory. Examination of long-term memory suggests that 5-HT(1A)-like receptors are necessary for consolidation and important for recall, 5-HT(2) receptors are important for consolidation and recall, and 5-HT(7) receptors are involved in all three phases. Importantly, we have validated our pharmacological results with genetic experiments and showed that hypomorph strains for 5-HT(2)Dro and 5-HT(1B)Dro receptors, as well as knockdown of 5-HT(7)Dro mRNA, significantly impair performance in short-term memory. Our data highlight the importance of the serotonin system and individual serotonin receptors to influence olfactory learning and memory in the fly, and position the fly as a model system to study the role of serotonin in cognitive processes relevant to mammalian CNS function. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Elimination of a ligand gating site generates a supersensitive olfactory receptor.

    Science.gov (United States)

    Sharma, Kanika; Ahuja, Gaurav; Hussain, Ashiq; Balfanz, Sabine; Baumann, Arnd; Korsching, Sigrun I

    2016-06-21

    Olfaction poses one of the most complex ligand-receptor matching problems in biology due to the unparalleled multitude of odor molecules facing a large number of cognate olfactory receptors. We have recently deorphanized an olfactory receptor, TAAR13c, as a specific receptor for the death-associated odor cadaverine. Here we have modeled the cadaverine/TAAR13c interaction, exchanged predicted binding residues by site-directed mutagenesis, and measured the activity of the mutant receptors. Unexpectedly we observed a binding site for cadaverine at the external surface of the receptor, in addition to an internal binding site, whose mutation resulted in complete loss of activity. In stark contrast, elimination of the external binding site generated supersensitive receptors. Modeling suggests this site to act as a gate, limiting access of the ligand to the internal binding site and thereby downregulating the affinity of the native receptor. This constitutes a novel mechanism to fine-tune physiological sensitivity to socially relevant odors.

  18. Expression of ionotropic receptors in terrestrial hermit crab’s olfactory sensory neurons

    Directory of Open Access Journals (Sweden)

    Katrin Christine Groh-Lunow

    2015-02-01

    Full Text Available Coenobitidae are one out of at least five crustacean lineages which independently succeeded in the transition from water to land. This change in lifestyle required adaptation of the peripheral olfactory organs, the antennules, in order to sense chemical cues in the new terrestrial habitat. Hermit crab olfactory aesthetascs are arranged in a field on the distal segment of the antennular flagellum. Aesthetascs house approximately 300 dendrites with their cell bodies arranged in spindle-like complexes of ca. 150 cell bodies each. While the aesthetascs of aquatic crustaceans have been shown to be the place of odor uptake and previous studies identified ionotropic receptors (IRs as the putative chemosensory receptors expressed in decapod antennules, the expression of IRs besides the IR co-receptors IR25a and IR93a in olfactory sensory neurons (OSNs has not been documented yet. Our goal was to reveal the expression and distribution pattern of non-co-receptor IRs in OSNs of Coenobita clypeatus, a terrestrial hermit crab, with RNA in situ hybridization. We expanded our previously published RNAseq dataset, and revealed 22 novel IR candidates in the Coenobita antennules. We then used RNA probes directed against three different IRs to visualize their expression within the OSN cell body complexes. Furthermore we aimed to characterize ligand spectra of single aesthetascs by recording local field potentials and responses from individual dendrites. This also allowed comparison to functional data from insect OSNs expressing antennal IRs. We show that this orphan receptor subgroup with presumably non-olfactory function in insects is likely the basis of olfaction in terrestrial hermit crabs.

  19. Large-scale production and study of a synthetic G protein-coupled receptor: Human olfactory receptor 17-4

    Science.gov (United States)

    Cook, Brian L.; Steuerwald, Dirk; Kaiser, Liselotte; Graveland-Bikker, Johanna; Vanberghem, Melanie; Berke, Allison P.; Herlihy, Kara; Pick, Horst; Vogel, Horst; Zhang, Shuguang

    2009-01-01

    Although understanding of the olfactory system has progressed at the level of downstream receptor signaling and the wiring of olfactory neurons, the system remains poorly understood at the molecular level of the receptors and their interaction with and recognition of odorant ligands. The structure and functional mechanisms of these receptors still remain a tantalizing enigma, because numerous previous attempts at the large-scale production of functional olfactory receptors (ORs) have not been successful to date. To investigate the elusive biochemistry and molecular mechanisms of olfaction, we have developed a mammalian expression system for the large-scale production and purification of a functional OR protein in milligram quantities. Here, we report the study of human OR17-4 (hOR17-4) purified from a HEK293S tetracycline-inducible system. Scale-up of production yield was achieved through suspension culture in a bioreactor, which enabled the preparation of >10 mg of monomeric hOR17-4 receptor after immunoaffinity and size exclusion chromatography, with expression yields reaching 3 mg/L of culture medium. Several key post-translational modifications were identified using MS, and CD spectroscopy showed the receptor to be ≈50% α-helix, similar to other recently determined G protein-coupled receptor structures. Detergent-solubilized hOR17-4 specifically bound its known activating odorants lilial and floralozone in vitro, as measured by surface plasmon resonance. The hOR17-4 also recognized specific odorants in heterologous cells as determined by calcium ion mobilization. Our system is feasible for the production of large quantities of OR necessary for structural and functional analyses and research into OR biosensor devices. PMID:19581598

  20. The CC chemokine receptor 5 regulates olfactory and social recognition in mice.

    Science.gov (United States)

    Kalkonde, Y V; Shelton, R; Villarreal, M; Sigala, J; Mishra, P K; Ahuja, S S; Barea-Rodriguez, E; Moretti, P; Ahuja, S K

    2011-12-01

    Chemokines are chemotactic cytokines that regulate cell migration and are thought to play an important role in a broad range of inflammatory diseases. The availability of chemokine receptor blockers makes them an important therapeutic target. In vitro, chemokines are shown to modulate neurotransmission. However, it is not very clear if chemokines play a role in behavior and cognition. Here we evaluated the role of CC chemokine receptor 5 (CCR5) in various behavioral tasks in mice using Wt (Ccr5⁺/⁺) and Ccr5-null (Ccr5⁻/⁻)mice. Ccr5⁻/⁻ mice showed enhanced social recognition. Administration of CC chemokine ligand 3 (CCL3), one of the CCR5-ligands, impaired social recognition. Since the social recognition task is dependent on the sense of olfaction, we tested olfactory recognition for social and non-social scents in these mice. Ccr5⁻/⁻ mice had enhanced olfactory recognition for both these scents indicating that enhanced performance in social recognition task could be due to enhanced olfactory recognition in these mice. Spatial memory and aversive memory were comparable in Wt and Ccr5⁻/⁻ mice. Collectively, these results suggest that chemokines/chemokine receptors might play an important role in olfactory recognition tasks in mice and to our knowledge represents the first direct demonstration of an in vivo role of CCR5 in modulating social behavior in mice. These studies are important as CCR5 blockers are undergoing clinical trials and can potentially modulate behavior. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Activation of GABA(A) receptors in the accessory olfactory bulb does not prevent the formation of an olfactory memory in mice.

    Science.gov (United States)

    Otsuka, T; Hashida, M; Oka, T; Kaba, H

    2001-07-01

    When female mice are mated, they form a memory to the pheromonal signal of their male partner. The neural mechanisms underlying this memory involve changes at the reciprocal dendrodendritic synapses between glutamatergic mitral cells and gamma-aminobutyric acid (GABA)-ergic granule cells in the accessory olfactory bulb (AOB). Blockade of GABA(A) receptors in the AOB leads to the formation of an olfactory memory. In an attempt to disrupt memory formation at mating, we used local infusions of the GABA(A) receptor agonist muscimol into the AOB during the critical period for memory formation. Muscimol across a wide range of doses (1-1000 pmol) did not prevent memory formation. The resistance of this memory to GABA(A) receptor activation may reflect the complexity of synaptic microcircuits in the AOB.

  2. Post-eclosion odor experience modifies olfactory receptor neuron coding in Drosophila.

    Science.gov (United States)

    Iyengar, Atulya; Chakraborty, Tuhin Subhra; Goswami, Sarit Pati; Wu, Chun-Fang; Siddiqi, Obaid

    2010-05-25

    Olfactory responses of Drosophila undergo pronounced changes after eclosion. The flies develop attraction to odors to which they are exposed and aversion to other odors. Behavioral adaptation is correlated with changes in the firing pattern of olfactory receptor neurons (ORNs). In this article, we present an information-theoretic analysis of the firing pattern of ORNs. Flies reared in a synthetic odorless medium were transferred after eclosion to three different media: (i) a synthetic medium relatively devoid of odor cues, (ii) synthetic medium infused with a single odorant, and (iii) complex cornmeal medium rich in odors. Recordings were made from an identified sensillum (type II), and the Jensen-Shannon divergence (D(JS)) was used to assess quantitatively the differences between ensemble spike responses to different odors. Analysis shows that prolonged exposure to ethyl acetate and several related esters increases sensitivity to these esters but does not improve the ability of the fly to distinguish between them. Flies exposed to cornmeal display varied sensitivity to these odorants and at the same time develop greater capacity to distinguish between odors. Deprivation of odor experience on an odorless synthetic medium leads to a loss of both sensitivity and acuity. Rich olfactory experience thus helps to shape the ORNs response and enhances its discriminative power. The experiments presented here demonstrate an experience-dependent adaptation at the level of the receptor neuron.

  3. Efficient olfactory coding in the pheromone receptor neuron of a moth.

    Directory of Open Access Journals (Sweden)

    Lubomir Kostal

    2008-04-01

    Full Text Available The concept of coding efficiency holds that sensory neurons are adapted, through both evolutionary and developmental processes, to the statistical characteristics of their natural stimulus. Encouraged by the successful invocation of this principle to predict how neurons encode natural auditory and visual stimuli, we attempted its application to olfactory neurons. The pheromone receptor neuron of the male moth Antheraea polyphemus, for which quantitative properties of both the natural stimulus and the reception processes are available, was selected. We predicted several characteristics that the pheromone plume should possess under the hypothesis that the receptors perform optimally, i.e., transfer as much information on the stimulus per unit time as possible. Our results demonstrate that the statistical characteristics of the predicted stimulus, e.g., the probability distribution function of the stimulus concentration, the spectral density function of the stimulation course, and the intermittency, are in good agreement with those measured experimentally in the field. These results should stimulate further quantitative studies on the evolutionary adaptation of olfactory nervous systems to odorant plumes and on the plume characteristics that are most informative for the 'sniffer'. Both aspects are relevant to the design of olfactory sensors for odour-tracking robots.

  4. Dynamic evolution of bitter taste receptor genes in vertebrates

    Directory of Open Access Journals (Sweden)

    Jones Gareth

    2009-01-01

    Full Text Available Abstract Background Sensing bitter tastes is crucial for many animals because it can prevent them from ingesting harmful foods. This process is mainly mediated by the bitter taste receptors (T2R, which are largely expressed in the taste buds. Previous studies have identified some T2R gene repertoires, and marked variation in repertoire size has been noted among species. However, the mechanisms underlying the evolution of vertebrate T2R genes remain poorly understood. Results To better understand the evolutionary pattern of these genes, we identified 16 T2R gene repertoires based on the high coverage genome sequences of vertebrates and studied the evolutionary changes in the number of T2R genes during birth-and-death evolution using the reconciled-tree method. We found that the number of T2R genes and the fraction of pseudogenes vary extensively among species. Based on the results of phylogenetic analysis, we showed that T2R gene families in teleost fishes are more diverse than those in tetrapods. In addition to the independent gene expansions in teleost fishes, frogs and mammals, lineage-specific gene duplications were also detected in lizards. Furthermore, extensive gains and losses of T2R genes were detected in each lineage during their evolution, resulting in widely differing T2R gene repertoires. Conclusion These results further support the hypotheses that T2R gene repertoires are closely related to the dietary habits of different species and that birth-and-death evolution is associated with adaptations to dietary changes.

  5. Lateral presynaptic inhibition mediates gain control in an olfactory circuit.

    Science.gov (United States)

    Olsen, Shawn R; Wilson, Rachel I

    2008-04-24

    Olfactory signals are transduced by a large family of odorant receptor proteins, each of which corresponds to a unique glomerulus in the first olfactory relay of the brain. Crosstalk between glomeruli has been proposed to be important in olfactory processing, but it is not clear how these interactions shape the odour responses of second-order neurons. In the Drosophila antennal lobe (a region analogous to the vertebrate olfactory bulb), we selectively removed most interglomerular input to genetically identified second-order olfactory neurons. Here we show that this broadens the odour tuning of these neurons, implying that interglomerular inhibition dominates over interglomerular excitation. The strength of this inhibitory signal scales with total feedforward input to the entire antennal lobe, and has similar tuning in different glomeruli. A substantial portion of this interglomerular inhibition acts at a presynaptic locus, and our results imply that this is mediated by both ionotropic and metabotropic receptors on the same nerve terminal.

  6. Supersensitive detection and discrimination of enantiomers by dorsal olfactory receptors: evidence for hierarchical odour coding.

    Science.gov (United States)

    Sato, Takaaki; Kobayakawa, Reiko; Kobayakawa, Ko; Emura, Makoto; Itohara, Shigeyoshi; Kizumi, Miwako; Hamana, Hiroshi; Tsuboi, Akio; Hirono, Junzo

    2015-09-11

    Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (-)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite "supersensitivity" to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 10(8)-fold differential sensitivity of ΔD mice to (-)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >10(10)-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (-)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This "enantiomer odour discrimination paradox" indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification.

  7. Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: A patch clamp analysis in gene-targeted mice

    OpenAIRE

    Grosmaitre, Xavier; Vassalli, Anne; Mombaerts, Peter; Shepherd, Gordon M.; Ma, Minghong

    2006-01-01

    A glomerulus in the mammalian olfactory bulb receives axonal inputs from olfactory sensory neurons (OSNs) that express the same odorant receptor (OR). Glomeruli are generally thought to represent functional units of olfactory coding, but there are no data on the electrophysiological properties of OSNs that express the same endogenous OR. Here, using patch clamp recordings in an intact epithelial preparation, we directly measured the transduction currents and receptor potentials from the dendr...

  8. Expression patterns of odorant receptors and response properties of olfactory sensory neurons in aged mice.

    Science.gov (United States)

    Lee, Anderson C; Tian, Huikai; Grosmaitre, Xavier; Ma, Minghong

    2009-10-01

    The sense of smell deteriorates in normal aging, but the underling mechanisms are still elusive. Here we investigated age-related alterations in expression patterns of odorant receptor (OR) genes and functional properties of olfactory sensory neurons (OSNs)-2 critical factors that define the odor detection threshold in the olfactory epithelium. Using in situ hybridization for 9 representative OR genes, we compared the cell densities of each OR in coronal nose sections at different ages (3-27 months). The cell density for different ORs peaked at different time points and a decline was observed for 6 of 9 ORs at advanced ages. Using patch clamp recordings, we then examined the odorant responses of individual OSNs coexpressing a defined OR (MOR23) and green fluorescent protein. The MOR23 neurons recorded from aged animals maintained a similar sensitivity and dynamic range in response to the cognate odorant (lyral) as those from younger mice. The results indicate that although the cell densities of OSNs expressing certain types of ORs decline at advanced ages, individual OSNs can retain their sensitivity. The implications of these findings in age-related olfactory deterioration are discussed.

  9. Modification of Male Courtship Motivation by Olfactory Habituation via the GABAA Receptor in Drosophila melanogaster

    Science.gov (United States)

    Tachibana, Shin-Ichiro; Touhara, Kazushige; Ejima, Aki

    2015-01-01

    A male-specific component, 11-cis-vaccenyl acetate (cVA) works as an anti-aphrodisiac pheromone in Drosophila melanogaster. The presence of cVA on a male suppresses the courtship motivation of other males and contributes to suppression of male-male homosexual courtship, while the absence of cVA on a female stimulates the sexual motivation of nearby males and enhances the male-female interaction. However, little is known how a male distinguishes the presence or absence of cVA on a target fly from either self-produced cVA or secondhand cVA from other males in the vicinity. In this study, we demonstrate that male flies have keen sensitivity to cVA; therefore, the presence of another male in the area reduces courtship toward a female. This reduced level of sexual motivation, however, could be overcome by pretest odor exposure via olfactory habituation to cVA. Real-time imaging of cVA-responsive sensory neurons using the neural activity sensor revealed that prolonged exposure to cVA decreased the levels of cVA responses in the primary olfactory center. Pharmacological and genetic screening revealed that signal transduction via GABAA receptors contributed to this olfactory habituation. We also found that the habituation experience increased the copulation success of wild-type males in a group. In contrast, transgenic males, in which GABA input in a small subset of local neurons was blocked by RNAi, failed to acquire the sexual advantage conferred by habituation. Thus, we illustrate a novel phenomenon in which olfactory habituation positively affects sexual capability in a competitive environment. PMID:26252206

  10. Residue conservation and dimer-interface analysis of olfactory receptor molecular models

    Directory of Open Access Journals (Sweden)

    Ramanathan Sowdhamini

    2012-10-01

    Full Text Available Olfactory Receptors (ORs are members of the Class A rhodopsin like G-protein coupled receptors (GPCRs which are the initial players in the signal transduction cascade, leading to the generation of nerve impulses transmitted to the brain and resulting in the detection of odorant molecules. Despite the accumulation of thousands of olfactory receptor sequences, no crystal structures of ORs are known tο date. However, the recent availability of crystallographic models of a few GPCRs allows us to generate homology models of ORs and analyze their amino acid patterns, as there is a huge diversity in OR sequences. In this study, we have generated three-dimensional models of 100 representative ORs from Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans and Sacharomyces cerevisiae which were selected on the basis of a composite classification scheme and phylogenetic analysis. The crystal structure of bovine rhodopsin was used as a template and it was found that the full-length models have more than 90% of their residues in allowed regions of the Ramachandran plot. The structures were further used for analysis of conserved residues in the transmembrane and extracellular loop regions in order to identify functionally important residues. Several ORs are known to be functional as dimers and hence dimer interfaces were predicted for OR models to analyse their oligomeric functional state.

  11. Promotion of cancer cell invasiveness and metastasis emergence caused by olfactory receptor stimulation.

    Directory of Open Access Journals (Sweden)

    Guenhaël Sanz

    Full Text Available Olfactory receptors (ORs are expressed in the olfactory epithelium, where they detect odorants, but also in other tissues with additional functions. Some ORs are even overexpressed in tumor cells. In this study, we identified ORs expressed in enterochromaffin tumor cells by RT-PCR, showing that single cells can co-express several ORs. Some of the receptors identified were already reported in other tumors, but they are orphan (without known ligand, as it is the case for most of the hundreds of human ORs. Thus, genes coding for human ORs with known ligands were transfected into these cells, expressing functional heterologous ORs. The in vitro stimulation of these cells by the corresponding OR odorant agonists promoted cell invasion of collagen gels. Using LNCaP prostate cancer cells, the stimulation of the PSGR (Prostate Specific G protein-coupled Receptor, an endogenously overexpressed OR, by β-ionone, its odorant agonist, resulted in the same phenotypic change. We also showed the involvement of a PI3 kinase γ dependent signaling pathway in this promotion of tumor cell invasiveness triggered by OR stimulation. Finally, after subcutaneous inoculation of LNCaP cells into NSG immunodeficient mice, the in vivo stimulation of these cells by the PSGR agonist β-ionone significantly enhanced metastasis emergence and spreading.

  12. Characterization of the Olfactory Receptor OR10H1 in Human Urinary Bladder Cancer.

    Science.gov (United States)

    Weber, Lea; Schulz, Wolfgang A; Philippou, Stathis; Eckardt, Josephine; Ubrig, Burkhard; Hoffmann, Michéle J; Tannapfel, Andrea; Kalbe, Benjamin; Gisselmann, Günter; Hatt, Hanns

    2018-01-01

    Olfactory receptors (ORs) are a large group of G-protein coupled receptors predominantly found in the olfactory epithelium. Many ORs are, however, ectopically expressed in other tissues and involved in several diseases including cancer. In this study, we describe that one OR, OR10H1, is predominantly expressed in the human urinary bladder with a notably higher expression at mRNA and protein level in bladder cancer tissues. Interestingly, also significantly higher amounts of OR10H1 transcripts were detectable in the urine of bladder cancer patients than in the urine of control persons. We identified the sandalwood-related compound Sandranol as a specific agonist of OR10H1. This deorphanization allowed the functional characterization of OR10H1 in BFTC905 bladder cancer cells. The effect of receptor activation was morphologically apparent in cell rounding, accompanied by changes in the cytoskeleton detected by β-actin, T-cadherin and β-Catenin staining. In addition, Sandranol treatment significantly diminished cell viability, cell proliferation and migration and induced a limited degree of apoptosis. Cell cycle analysis revealed an increased G1 fraction. In a concentration-dependent manner, Sandranol application elevated cAMP levels, which was reduced by inhibition of adenylyl cyclase, and elicited intracellular Ca 2+ concentration increase. Furthermore, activation of OR10H1 enhanced secretion of ATP and serotonin. Our results suggest OR10H1 as a potential biomarker and therapeutic target for bladder cancer.

  13. Characterization of the Olfactory Receptor OR10H1 in Human Urinary Bladder Cancer

    Directory of Open Access Journals (Sweden)

    Lea Weber

    2018-05-01

    Full Text Available Olfactory receptors (ORs are a large group of G-protein coupled receptors predominantly found in the olfactory epithelium. Many ORs are, however, ectopically expressed in other tissues and involved in several diseases including cancer. In this study, we describe that one OR, OR10H1, is predominantly expressed in the human urinary bladder with a notably higher expression at mRNA and protein level in bladder cancer tissues. Interestingly, also significantly higher amounts of OR10H1 transcripts were detectable in the urine of bladder cancer patients than in the urine of control persons. We identified the sandalwood-related compound Sandranol as a specific agonist of OR10H1. This deorphanization allowed the functional characterization of OR10H1 in BFTC905 bladder cancer cells. The effect of receptor activation was morphologically apparent in cell rounding, accompanied by changes in the cytoskeleton detected by β-actin, T-cadherin and β-Catenin staining. In addition, Sandranol treatment significantly diminished cell viability, cell proliferation and migration and induced a limited degree of apoptosis. Cell cycle analysis revealed an increased G1 fraction. In a concentration-dependent manner, Sandranol application elevated cAMP levels, which was reduced by inhibition of adenylyl cyclase, and elicited intracellular Ca2+ concentration increase. Furthermore, activation of OR10H1 enhanced secretion of ATP and serotonin. Our results suggest OR10H1 as a potential biomarker and therapeutic target for bladder cancer.

  14. Ancestral amphibian v2rs are expressed in the main olfactory epithelium

    Science.gov (United States)

    Syed, Adnan S.; Sansone, Alfredo; Nadler, Walter; Manzini, Ivan; Korsching, Sigrun I.

    2013-01-01

    Mammalian olfactory receptor families are segregated into different olfactory organs, with type 2 vomeronasal receptor (v2r) genes expressed in a basal layer of the vomeronasal epithelium. In contrast, teleost fish v2r genes are intermingled with all other olfactory receptor genes in a single sensory surface. We report here that, strikingly different from both lineages, the v2r gene family of the amphibian Xenopus laevis is expressed in the main olfactory as well as the vomeronasal epithelium. Interestingly, late diverging v2r genes are expressed exclusively in the vomeronasal epithelium, whereas “ancestral” v2r genes, including the single member of v2r family C, are restricted to the main olfactory epithelium. Moreover, within the main olfactory epithelium, v2r genes are expressed in a basal zone, partially overlapping, but clearly distinct from an apical zone of olfactory marker protein and odorant receptor-expressing cells. These zones are also apparent in the spatial distribution of odor responses, enabling a tentative assignment of odor responses to olfactory receptor gene families. Responses to alcohols, aldehydes, and ketones show an apical localization, consistent with being mediated by odorant receptors, whereas amino acid responses overlap extensively with the basal v2r-expressing zone. The unique bimodal v2r expression pattern in main and accessory olfactory system of amphibians presents an excellent opportunity to study the transition of v2r gene expression during evolution of higher vertebrates. PMID:23613591

  15. Underlying mathematics in diversification of human olfactory receptors in different loci.

    Science.gov (United States)

    Hassan, Sk Sarif; Choudhury, Pabitra Pal; Goswami, Arunava

    2013-12-01

    As per conservative estimate, approximately 51-105 Olfactory Receptors (ORs) loci are present in human genome occurring in clusters. These clusters are apparently unevenly spread as mosaics over 21 pairs of human chromosomes. Olfactory Receptor (OR) gene families which are thought to have expanded for the need to provide recognition capability for a huge number of pure and complex odorants, form the largest known multigene family in the human genome. Recent studies have shown that 388 full length and 414 OR pseudo-genes are present in these OR genomic clusters. In this paper, the authors report a classification method for all human ORs based on their sequential quantitative information like presence of poly strings of nucleotides bases, long range correlation and so on. An L-System generated sequence has been taken as an input into a star-model of specific subfamily members and resultant sequence has been mapped to a specific OR based on the classification scheme using fractal parameters like Hurst exponent and fractal dimensions.

  16. Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: Tales from Testing the Vibration Theory.

    Science.gov (United States)

    Paoli, M; Münch, D; Haase, A; Skoulakis, E; Turin, L; Galizia, C G

    2017-01-01

    Several studies have attempted to test the vibrational hypothesis of odorant receptor activation in behavioral and physiological studies using deuterated compounds as odorants. The results have been mixed. Here, we attempted to test how deuterated compounds activate odorant receptors using calcium imaging of the fruit fly antennal lobe. We found specific activation of one area of the antennal lobe corresponding to inputs from a specific receptor. However, upon more detailed analysis, we discovered that an impurity of 0.0006% ethyl acetate in a chemical sample of benzaldehyde-d 5 was entirely responsible for a sizable odorant-evoked response in Drosophila melanogaster olfactory receptor cells expressing dOr42b. Without gas chromatographic purification within the experimental setup, this impurity would have created a difference in the responses of deuterated and nondeuterated benzaldehyde, suggesting that dOr42b be a vibration sensitive receptor, which we show here not to be the case. Our results point to a broad problem in the literature on use of non-GC-pure compounds to test receptor selectivity, and we suggest how the limitations can be overcome in future studies.

  17. Anatomical and molecular consequences of Unilateral Naris Closure on two populations of olfactory sensory neurons expressing defined odorant receptors.

    Science.gov (United States)

    Molinas, Adrien; Aoudé, Imad; Soubeyre, Vanessa; Tazir, Bassim; Cadiou, Hervé; Grosmaitre, Xavier

    2016-07-28

    Mammalian olfactory sensory neurons (OSNs), the primary elements of the olfactory system, are located in the olfactory epithelium lining the nasal cavity. Exposed to the environment, their lifespan is short. Consequently, OSNs are regularly regenerated and several reports show that activity strongly modulates their development and regeneration: the peripheral olfactory system can adjust to the amount of stimulus through compensatory mechanisms. Unilateral naris occlusion (UNO) was frequently used to investigate this mechanism at the entire epithelium level. However, there is little data regarding the effects of UNO at the cellular level, especially on individual neuronal populations expressing a defined odorant receptor. Here, using UNO during the first three postnatal weeks, we analyzed the anatomical and molecular consequences of sensory deprivation in OSNs populations expressing the MOR23 and M71 receptors. The density of MOR23-expressing neurons is decreased in the closed side while UNO does not affect the density of M71-expressing neurons. Using Real Time qPCR on isolated neurons, we observed that UNO modulates the transcript levels for transduction pathway proteins (odorant receptors, CNGA2, PDE1c). The transcripts modulated by UNO will differ between populations depending on the receptor expressed. These results suggest that sensory deprivation will have different effects on different OSNs' populations. As a consequence, early experience will shape the functional properties of OSNs differently depending on the type of odorant receptor they express. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. The Biogenic Amine Tyramine and its Receptor (AmTyr1 in Olfactory Neuropils in the Honey Bee (Apis mellifera Brain

    Directory of Open Access Journals (Sweden)

    Irina T. Sinakevitch

    2017-10-01

    Full Text Available This article describes the cellular sources for tyramine and the cellular targets of tyramine via the Tyramine Receptor 1 (AmTyr1 in the olfactory learning and memory neuropils of the honey bee brain. Clusters of approximately 160 tyramine immunoreactive neurons are the source of tyraminergic fibers with small varicosities in the optic lobes, antennal lobes, lateral protocerebrum, mushroom body (calyces and gamma lobes, tritocerebrum and subesophageal ganglion (SEG. Our tyramine mapping study shows that the primary sources of tyramine in the antennal lobe and calyx of the mushroom body are from at least two Ventral Unpaired Median neurons (VUMmd and VUMmx with cell bodies in the SEG. To reveal AmTyr1 receptors in the brain, we used newly characterized anti-AmTyr1 antibodies. Immunolocalization studies in the antennal lobe with anti-AmTyr1 antibodies showed that the AmTyr1 expression pattern is mostly in the presynaptic sites of olfactory receptor neurons (ORNs. In the mushroom body calyx, anti-AmTyr1 mapped the presynaptic sites of uniglomerular Projection Neurons (PNs located primarily in the microglomeruli of the lip and basal ring calyx area. Release of tyramine/octopamine from VUM (md and mx neurons in the antennal lobe and mushroom body calyx would target AmTyr1 expressed on ORN and uniglomerular PN presynaptic terminals. The presynaptic location of AmTyr1, its structural similarity with vertebrate alpha-2 adrenergic receptors, and previous pharmacological evidence suggests that it has an important role in the presynaptic inhibitory control of neurotransmitter release.

  19. Characterization and Comparative Analysis of Olfactory Receptor Co-Receptor Orco Orthologs Among Five Mirid Bug Species

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2018-03-01

    Full Text Available The phytophagous mirid bugs of Apolygus lucorum, Lygus pratensis as well as three Adelphocoris spp., including Adelphocoris lineolatus, A. suturalis, and A. fasciaticollis are major pests of multiple agricultural crops in China, which have distinct geographical distribution and occurrence ranges. Like many insect species, these bugs heavily rely on olfactory cues to search preferred host plants, thereby investigation on functional co-evolution and divergence of olfactory genes seems to be necessary and is of great interest. In the odorant detection pathway, olfactory receptor co-receptor (Orco plays critical role in the perception of odors. In this study, we identified the full-length cDNA sequences encoding three putative Orcos (AsutOrco, AfasOrco, and LpraOrco in bug species of A. suturalis, A. fasciaticollis, and L. pratensis based on homology cloning method. Next, sequence alignment, membrane topology and gene structure analysis showed that these three Orco orthologs together with previously reported AlinOrco and AlucOrco shared high amino acid identities and similar topology structure, but had different gene structure especially at the length and insertion sites of introns. Furthermore, the evolutional estimation on the ratios of non-synonymous to synonymous (Ka/Ks revealed that Orco genes were under strong purifying selection, but the degrees of variation were significant different between genera. The results of quantitative real-time PCR experiments showed that these five Orco genes had a similar antennae-biased tissue expression pattern. Taking these data together, it is thought that Orco genes in the mirid species could share conserved olfaction roles but had different evolution rates. These findings would lay a foundation to further investigate the molecular mechanisms of evolutionary interactions between mirid bugs and their host plants, which might in turn contribute to the development of pest management strategy for mirid bugs.

  20. Dynamical modeling of the moth pheromone-sensitive olfactory receptor neuron within its sensillar environment.

    Directory of Open Access Journals (Sweden)

    Yuqiao Gu

    Full Text Available In insects, olfactory receptor neurons (ORNs, surrounded with auxiliary cells and protected by a cuticular wall, form small discrete sensory organs--the sensilla. The moth pheromone-sensitive sensillum is a well studied example of hair-like sensillum that is favorable to both experimental and modeling investigations. The model presented takes into account both the molecular processes of ORNs, i.e. the biochemical reactions and ionic currents giving rise to the receptor potential, and the cellular organization and compartmentalization of the organ represented by an electrical circuit. The number of isopotential compartments needed to describe the long dendrite bearing pheromone receptors was determined. The transduction parameters that must be modified when the number of compartments is increased were identified. This model reproduces the amplitude and time course of the experimentally recorded receptor potential. A first complete version of the model was analyzed in response to pheromone pulses of various strengths. It provided a quantitative description of the spatial and temporal evolution of the pheromone-dependent conductances, currents and potentials along the outer dendrite and served to determine the contribution of the various steps in the cascade to its global sensitivity. A second simplified version of the model, utilizing a single depolarizing conductance and leak conductances for repolarizing the ORN, was derived from the first version. It served to analyze the effects on the sensory properties of varying the electrical parameters and the size of the main sensillum parts. The consequences of the results obtained on the still uncertain mechanisms of olfactory transduction in moth ORNs--involvement or not of G-proteins, role of chloride and potassium currents--are discussed as well as the optimality of the sensillum organization, the dependence of biochemical parameters on the neuron spatial extension and the respective contributions

  1. High-resolution copy-number variation map reflects human olfactory receptor diversity and evolution.

    Directory of Open Access Journals (Sweden)

    Yehudit Hasin

    2008-11-01

    Full Text Available Olfactory receptors (ORs, which are involved in odorant recognition, form the largest mammalian protein superfamily. The genomic content of OR genes is considerably reduced in humans, as reflected by the relatively small repertoire size and the high fraction ( approximately 55% of human pseudogenes. Since several recent low-resolution surveys suggested that OR genomic loci are frequently affected by copy-number variants (CNVs, we hypothesized that CNVs may play an important role in the evolution of the human olfactory repertoire. We used high-resolution oligonucleotide tiling microarrays to detect CNVs across 851 OR gene and pseudogene loci. Examining genomic DNA from 25 individuals with ancestry from three populations, we identified 93 OR gene loci and 151 pseudogene loci affected by CNVs, generating a mosaic of OR dosages across persons. Our data suggest that approximately 50% of the CNVs involve more than one OR, with the largest CNV spanning 11 loci. In contrast to earlier reports, we observe that CNVs are more frequent among OR pseudogenes than among intact genes, presumably due to both selective constraints and CNV formation biases. Furthermore, our results show an enrichment of CNVs among ORs with a close human paralog or lacking a one-to-one ortholog in chimpanzee. Interestingly, among the latter we observed an enrichment in CNV losses over gains, a finding potentially related to the known diminution of the human OR repertoire. Quantitative PCR experiments performed for 122 sampled ORs agreed well with the microarray results and uncovered 23 additional CNVs. Importantly, these experiments allowed us to uncover nine common deletion alleles that affect 15 OR genes and five pseudogenes. Comparison to the chimpanzee reference genome revealed that all of the deletion alleles are human derived, therefore indicating a profound effect of human-specific deletions on the individual OR gene content. Furthermore, these deletion alleles may be used

  2. Mechanisms underlying odorant-induced and spontaneous calcium signals in olfactory receptor neurons of spiny lobsters, Panulirus argus.

    Science.gov (United States)

    Tadesse, Tizeta; Derby, Charles D; Schmidt, Manfred

    2014-01-01

    We determined if a newly developed antennule slice preparation allows studying chemosensory properties of spiny lobster olfactory receptor neurons under in situ conditions with Ca(2+) imaging. We show that chemical stimuli reach the dendrites of olfactory receptor neurons but not their somata, and that odorant-induced Ca(2+) signals in the somata are sufficiently stable over time to allow stimulation with a substantial number of odorants. Pharmacological manipulations served to elucidate the source of odorant-induced Ca(2+) transients and spontaneous Ca(2+) oscillations in the somata of olfactory receptor neurons. Both Ca(2+) signals are primarily mediated by an influx of extracellular Ca(2+) through voltage-activated Ca(2+) channels that can be blocked by CoCl2 and the L-type Ca(2+) channel blocker verapamil. Intracellular Ca(2+) stores contribute little to odorant-induced Ca(2+) transients and spontaneous Ca(2+) oscillations. The odorant-induced Ca(2+) transients as well as the spontaneous Ca(2+) oscillations depend on action potentials mediated by Na(+) channels that are largely TTX-insensitive but blocked by the local anesthetics tetracaine and lidocaine. Collectively, these results corroborate the conclusion that odorant-induced Ca(2+) transients and spontaneous Ca(2+) oscillations in the somata of olfactory receptor neurons closely reflect action potential activity associated with odorant-induced phasic-tonic responses and spontaneous bursting, respectively. Therefore, both types of Ca(2+) signals represent experimentally accessible proxies of spiking.

  3. Mesencephalic dopaminergic neurons express a repertoire of olfactory receptors and respond to odorant-like molecules.

    Science.gov (United States)

    Grison, Alice; Zucchelli, Silvia; Urzì, Alice; Zamparo, Ilaria; Lazarevic, Dejan; Pascarella, Giovanni; Roncaglia, Paola; Giorgetti, Alejandro; Garcia-Esparcia, Paula; Vlachouli, Christina; Simone, Roberto; Persichetti, Francesca; Forrest, Alistair R R; Hayashizaki, Yoshihide; Carloni, Paolo; Ferrer, Isidro; Lodovichi, Claudia; Plessy, Charles; Carninci, Piero; Gustincich, Stefano

    2014-08-27

    The mesencephalic dopaminergic (mDA) cell system is composed of two major groups of projecting cells in the Substantia Nigra (SN) (A9 neurons) and the Ventral Tegmental Area (VTA) (A10 cells). Selective degeneration of A9 neurons occurs in Parkinson's disease (PD) while abnormal function of A10 cells has been linked to schizophrenia, attention deficit and addiction. The molecular basis that underlies selective vulnerability of A9 and A10 neurons is presently unknown. By taking advantage of transgenic labeling, laser capture microdissection coupled to nano Cap-Analysis of Gene Expression (nanoCAGE) technology on isolated A9 and A10 cells, we found that a subset of Olfactory Receptors (OR)s is expressed in mDA neurons. Gene expression analysis was integrated with the FANTOM5 Helicos CAGE sequencing datasets, showing the presence of these ORs in selected tissues and brain areas outside of the olfactory epithelium. OR expression in the mesencephalon was validated by RT-PCR and in situ hybridization. By screening 16 potential ligands on 5 mDA ORs recombinantly expressed in an heterologous in vitro system, we identified carvone enantiomers as agonists at Olfr287 and able to evoke an intracellular Ca2+ increase in solitary mDA neurons. ORs were found expressed in human SN and down-regulated in PD post mortem brains. Our study indicates that mDA neurons express ORs and respond to odor-like molecules providing new opportunities for pharmacological intervention in disease.

  4. Olfactory Perceptual Learning Requires Action of Noradrenaline in the Olfactory Bulb: Comparison with Olfactory Associative Learning

    Science.gov (United States)

    Vinera, Jennifer; Kermen, Florence; Sacquet, Joëlle; Didier, Anne; Mandairon, Nathalie; Richard, Marion

    2015-01-01

    Noradrenaline contributes to olfactory-guided behaviors but its role in olfactory learning during adulthood is poorly documented. We investigated its implication in olfactory associative and perceptual learning using local infusion of mixed a1-ß adrenergic receptor antagonist (labetalol) in the adult mouse olfactory bulb. We reported that…

  5. Odorant responsiveness of embryonic mouse olfactory sensory neurons expressing the odorant receptors S1 or MOR23.

    Science.gov (United States)

    Lam, Rebecca S; Mombaerts, Peter

    2013-07-01

    The mammalian olfactory system has developed some functionality by the time of birth. There is behavioral and limited electrophysiological evidence for prenatal olfaction in various mammalian species. However, there have been no reports, in any mammalian species, of recordings from prenatal olfactory sensory neurons (OSNs) that express a given odorant receptor (OR) gene. Here we have performed patch-clamp recordings from mouse OSNs that express the OR gene S1 or MOR23, using the odorous ligands 2-phenylethyl alcohol or lyral, respectively. We found that, out of a combined total of 20 OSNs from embryos of these two strains at embryonic day (E)16.5 or later, all responded to a cognate odorous ligand. By contrast, none of six OSNs responded to the ligand at E14.5 or E15.5. The kinetics of the odorant-evoked electrophysiological responses of prenatal OSNs are similar to those of postnatal OSNs. The S1 and MOR23 glomeruli in the olfactory bulb are formed postnatally, but the axon terminals of OSNs expressing these OR genes may be synaptically active in the olfactory bulb at embryonic stages. The upper limit of the acquisition of odorant responsiveness for S1 and MOR23 OSNs at E16.5 is consistent with the developmental expression patterns of components of the olfactory signaling pathway. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  6. Olfactory receptor signaling is regulated by the post-synaptic density 95, Drosophila discs large, zona-occludens 1 (PDZ) scaffold multi-PDZ domain protein 1.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2009-12-01

    The unique ability of mammals to detect and discriminate between thousands of different odorant molecules is governed by the diverse array of olfactory receptors expressed by olfactory sensory neurons in the nasal epithelium. Olfactory receptors consist of seven transmembrane domain G protein-coupled receptors and comprise the largest gene superfamily in the mammalian genome. We found that approximately 30% of olfactory receptors possess a classical post-synaptic density 95, Drosophila discs large, zona-occludens 1 (PDZ) domain binding motif in their C-termini. PDZ domains have been established as sites for protein-protein interaction and play a central role in organizing diverse cell signaling assemblies. In the present study, we show that multi-PDZ domain protein 1 (MUPP1) is expressed in the apical compartment of olfactory sensory neurons. Furthermore, on heterologous co-expression with olfactory sensory neurons, MUPP1 was shown to translocate to the plasma membrane. We found direct interaction of PDZ domains 1 + 2 of MUPP1 with the C-terminus of olfactory receptors in vitro. Moreover, the odorant-elicited calcium response of OR2AG1 showed a prolonged decay in MUPP1 small interfering RNA-treated cells. We have therefore elucidated the first building blocks of the putative \\'olfactosome\\

  7. Olfactory and solitary chemosensory cells: two different chemosensory systems in the nasal cavity of the American alligator, Alligator mississippiensis

    Directory of Open Access Journals (Sweden)

    Hansen Anne

    2007-08-01

    Full Text Available Abstract Background The nasal cavity of all vertebrates houses multiple chemosensors, either innervated by the Ist (olfactory or the Vth (trigeminal cranial nerve. Various types of receptor cells are present, either segregated in different compartments (e.g. in rodents or mingled in one epithelium (e.g. fish. In addition, solitary chemosensory cells have been reported for several species. Alligators which seek their prey both above and under water have only one nasal compartment. Information about their olfactory epithelium is limited. Since alligators seem to detect both volatile and water-soluble odour cues, I tested whether different sensory cell types are present in the olfactory epithelium. Results Electron microscopy and immunocytochemistry were used to examine the sensory epithelium of the nasal cavity of the American alligator. Almost the entire nasal cavity is lined with olfactory (sensory epithelium. Two types of olfactory sensory neurons are present. Both types bear cilia as well as microvilli at their apical endings and express the typical markers for olfactory neurons. The density of these olfactory neurons varies along the nasal cavity. In addition, solitary chemosensory cells innervated by trigeminal nerve fibres, are intermingled with olfactory sensory neurons. Solitary chemosensory cells express components of the PLC-transduction cascade found in solitary chemosensory cells in rodents. Conclusion The nasal cavity of the American alligator contains two different chemosensory systems incorporated in the same sensory epithelium: the olfactory system proper and solitary chemosensory cells. The olfactory system contains two morphological distinct types of ciliated olfactory receptor neurons.

  8. Sex bias in copy number variation of olfactory receptor gene family depends on ethnicity

    Directory of Open Access Journals (Sweden)

    Farideh eShadravan

    2013-03-01

    Full Text Available Gender plays a pivotal role in the human genetic identity and is also manifested in many genetic disorders particularly mental retardation. In this study its effect on copy number variation (CNV, known to cause genetic disorders was explored. As the olfactory receptor (OR repertoire comprises the largest human gene family, it was selected for this study, which was carried out within and between three populations, derived from 150 individuals from the 1000 Genome Project. Analysis of 3872 CNVs detected among 791 OR loci, in which 307 loci showed CNV, revealed the following novel findings: Sex bias in CNV was significantly more prevalent in uncommon than common CNV variants of OR pseudogenes, in which the male genome showed more CNVs; and in one-copy number loss compared to complete deletion of OR pseudogenes; both findings implying a more recent evolutionary role for gender. Sex bias in copy number gain was also detected. Another novel finding was that the observed six bias was largely dependent on ethnicity and was in general absent in East Asians. Using a CNV public database for sick children (ISCA the application of these findings for improving clinical molecular diagnostics is discussed by showing an example of sex bias in CNV among kids with autism. Additional clinical relevance is discussed, as the most polymorphic CNV-enriched OR cluster in the human genome, located on chr 15q11.2, is found near the PWS/AS bi-directionally imprinted region associated with two well-known mental retardation syndromes. As olfaction represents the primitive cognition in most mammals, arguably in competition with the development of a larger brain, the extensive retention of OR pseudogenes in females of this study, might point to a parent-of-origin indirect regulatory role for OR pseudogenes in the embryonic development of human brain. Thus any perturbation in the temporal regulation of olfactory system could lead to developmental delay disorders including

  9. Integrated Approaches for Genome-wide Interrogation of the Druggable Non-olfactory G Protein-coupled Receptor Superfamily.

    Science.gov (United States)

    Roth, Bryan L; Kroeze, Wesley K

    2015-08-07

    G-protein-coupled receptors (GPCRs) are frequent and fruitful targets for drug discovery and development, as well as being off-targets for the side effects of a variety of medications. Much of the druggable non-olfactory human GPCR-ome remains under-interrogated, and we present here various approaches that we and others have used to shine light into these previously dark corners of the human genome. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Evolution of ligand specificity in vertebrate corticosteroid receptors

    Directory of Open Access Journals (Sweden)

    Deitcher David L

    2011-01-01

    Full Text Available Abstract Background Corticosteroid receptors include mineralocorticoid (MR and glucocorticoid (GR receptors. Teleost fishes have a single MR and duplicate GRs that show variable sensitivities to mineralocorticoids and glucocorticoids. How these receptors compare functionally to tetrapod MR and GR, and the evolutionary significance of maintaining two GRs, remains unclear. Results We used up to seven steroids (including aldosterone, cortisol and 11-deoxycorticosterone [DOC] to compare the ligand specificity of the ligand binding domains of corticosteroid receptors between a mammal (Mus musculus and the midshipman fish (Porichthys notatus, a teleost model for steroid regulation of neural and behavioral plasticity. Variation in mineralocorticoid sensitivity was considered in a broader phylogenetic context by examining the aldosterone sensitivity of MR and GRs from the distantly related daffodil cichlid (Neolamprologus pulcher, another teleost model for neurobehavioral plasticity. Both teleost species had a single MR and duplicate GRs. All MRs were sensitive to DOC, consistent with the hypothesis that DOC was the initial ligand of the ancestral MR. Variation in GR steroid-specificity corresponds to nine identified amino acid residue substitutions rather than phylogenetic relationships based on receptor sequences. Conclusion The mineralocorticoid sensitivity of duplicate GRs in teleosts is highly labile in the context of their evolutionary phylogeny, a property that likely led to neo-functionalization and maintenance of two GRs.

  11. Early vertebrate chromosome duplications and the evolution of the neuropeptide Y receptor gene regions

    Directory of Open Access Journals (Sweden)

    Brenner Sydney

    2008-06-01

    Full Text Available Abstract Background One of the many gene families that expanded in early vertebrate evolution is the neuropeptide (NPY receptor family of G-protein coupled receptors. Earlier work by our lab suggested that several of the NPY receptor genes found in extant vertebrates resulted from two genome duplications before the origin of jawed vertebrates (gnathostomes and one additional genome duplication in the actinopterygian lineage, based on their location on chromosomes sharing several gene families. In this study we have investigated, in five vertebrate genomes, 45 gene families with members close to the NPY receptor genes in the compact genomes of the teleost fishes Tetraodon nigroviridis and Takifugu rubripes. These correspond to Homo sapiens chromosomes 4, 5, 8 and 10. Results Chromosome regions with conserved synteny were identified and confirmed by phylogenetic analyses in H. sapiens, M. musculus, D. rerio, T. rubripes and T. nigroviridis. 26 gene families, including the NPY receptor genes, (plus 3 described recently by other labs showed a tree topology consistent with duplications in early vertebrate evolution and in the actinopterygian lineage, thereby supporting expansion through block duplications. Eight gene families had complications that precluded analysis (such as short sequence length or variable number of repeated domains and another eight families did not support block duplications (because the paralogs in these families seem to have originated in another time window than the proposed genome duplication events. RT-PCR carried out with several tissues in T. rubripes revealed that all five NPY receptors were expressed in the brain and subtypes Y2, Y4 and Y8 were also expressed in peripheral organs. Conclusion We conclude that the phylogenetic analyses and chromosomal locations of these gene families support duplications of large blocks of genes or even entire chromosomes. Thus, these results are consistent with two early vertebrate

  12. Ligand-selective activation of heterologously-expressed mammalian olfactory receptor.

    Science.gov (United States)

    Ukhanov, K; Bobkov, Y; Corey, E A; Ache, B W

    2014-10-01

    Mammalian olfactory receptors (ORs) appear to have the capacity to couple to multiple G protein-coupled signaling pathways in a ligand-dependent selective manner. To better understand the mechanisms and molecular range of such ligand selectivity, we expressed the mouse eugenol OR (mOR-EG) in HEK293T cells together with Gα15 to monitor activation of the phospholipase-C (PLC) signaling pathway and/or Gαolf to monitor activation of the adenylate cyclase (AC) signaling pathway, resulting in intracellular Ca(2+) release and/or Ca(2+) influx through a cyclic nucleotide-gated channel, respectively. PLC-dependent responses differed dynamically from AC-dependent responses, allowing them to be distinguished when Gα15 and Gαolf were co-expressed. The dynamic difference in readout was independent of the receptor, the heterologous expression system, and the ligand concentration. Of 17 reported mOR-EG ligands tested, including eugenol, its analogs, and structurally dissimilar compounds (mousse cristal, nootkatone, orivone), some equally activated both signaling pathways, some differentially activated both signaling pathways, and some had no noticeable effect even at 1-5mM. Our findings argue that mOR-EG, when heterologously expressed, can couple to two different signaling pathways in a ligand selective manner. The challenge now is to determine the potential of mOR-EG, and perhaps other ORs, to activate multiple signaling pathways in a ligand selective manner in native ORNs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Reproduction phase-related expression of GnRH-like immunoreactivity in the olfactory receptor neurons, their projections to the olfactory bulb and in the nervus terminalis in the female Indian major carp Cirrhinus mrigala (Ham.).

    Science.gov (United States)

    Biju, K C; Singru, Praful S; Schreibman, Martin P; Subhedar, Nishikant

    2003-10-01

    The reproductive biology of the Indian major carp Cirrhinus mrigala is tightly synchronized with the seasonal changes in the environment. While the ovaries show growth from February through June, the fish spawn in July-August to coincide with the monsoon; thereafter the fish pass into the postspawning and resting phases. We investigated the pattern of GnRH immunoreactivity in the olfactory system at regular intervals extending over a period of 35 months. Although no signal was detected in the olfactory organ of fish collected from April through February following year, distinct GnRH-like immunoreactivity appeared in the fish collected in March. Intense immunoreactivity was noticed in several olfactory receptor neurons (ORNs) and their axonal fibers as they extend over the olfactory nerve, spread in the periphery of the olfactory bulb (OB), and terminate in the glomerular layer. Strong immunoreactivity was seen in some fascicles of the medial olfactory tracts extending from the OB to the telencephalon. Some neurons of the ganglion cells of nervus terminalis showed GnRH immunostaining during March; no immunoreactivity was detected at other times of the year. Plexus of GnRH immunoreactive fibers extending throughout the bulb represented a different component of the olfactory system; the fiber density showed a seasonal pattern that could be related to the status of gonadal maturity. While it was highest in the prespawning phase, significant reduction in the fiber density was noticed in the fish of spawning and the following regressive phases. Taken together the data suggest that the GnRH in the olfactory system of C. mrigala may play a major role in translation of the environmental cues and influence the downstream signals leading to the stimulation of the brain-pituitary-ovary axis.

  14. An olfactory receptor from Apolygus lucorum (Meyer-Dur) mainly tuned to volatiles from flowering host plants.

    Science.gov (United States)

    Yan, Shu-Wei; Zhang, Jin; Liu, Yang; Li, Guo-Qing; Wang, Gui-Rong

    2015-08-01

    Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is one of the most serious agricultural pests, feeding on a wide range of cultivated plants, including cotton, cereals and vegetables in the north of China. This insect can frequently switch between habitats and host plants over seasons and prefer plants in bloom. A. lucorum relies heavily on olfaction to locate its host plants finely discriminating different plant volatiles in the environment. Despite its economical importance, research on the olfactory system of this species has been so far very limited. In this study, we have identified and characterized an olfactory receptor which is sensitively tuned to (Z)-3-Hexenyl acetate and several flowering compounds. Besides being present in the bouquet of some flowers, these compounds are produced by plants that have suffered attacks and are supposed to act as chemical messengers between plants. This OR may play an important role in the selection of host plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Degradation rate of acetylcholine receptors inserted into denervated vertebrate neuromuscular junctions

    International Nuclear Information System (INIS)

    Shyng, S.L.; Salpeter, M.M.

    1989-01-01

    Many studies exist on the effect of denervation on the degradation of acetylcholine receptors (AChRs) at the vertebrate neuromuscular junction (nmj). These studies have described the behavior of either the total population of junctional receptors at different times after denervation, or of the receptors present at the time of denervation. No experimental studies yet exist on the degradation rate of the receptors newly inserted into denervated junctions. In the previous studies, the original receptors of mouse sternomastoid muscles were found to retain the slow degradation (t 1/2) of approximately 8-10 d of innervated junctional receptors for up to 10 d after denervation before accelerating to a t 1/2 of approximately 3 d. The total junctional receptors, on the other hand, showed a progressive increase in degradation rate from a t 1/2 of 8-10 d to a t 1/2 of 1 d. To reconcile these earlier observations, the present study examines the degradation of new receptors inserted into the nmj after denervation. To avoid possible contamination of the data with postdenervation extrajunctional receptors, we used transmission electron microscope autoradiography to study only receptors located at the postjunctional fold of the nmj. We established that the new receptors inserted into denervated junctions have a t 1/2 of approximately 1 d, considerably faster than that of the original receptors and equivalent to that of postdenervation extrajunctional receptors. Both original and new receptors are interspersed at the top of the junctional folds. Thus, until all the original receptors are degraded, the postjunctional membrane contains two populations of AChRs that maintain a total steady-state site density but degrade at different rates

  16. Haplotype specific alteration of diabetes MHC risk by olfactory receptor gene polymorphism.

    Science.gov (United States)

    Jahromi, Mohamed M

    2012-12-01

    Evidence for genes associated with risk for Type 1 diabetes (T1D) in the extended region of the major histocompatibility complex (MHC) genes is accumulating. The aim of this study was to investigate the association pattern of the extended MHC region with T1D susceptibility to identify effects independent of well established DR/DQ genes. A total of 394 Europid families with T1D were genotyped for the single nucleotide polymorphism (SNP) in the olfactory receptor family 14, subfamily J, member 1 (OR14J1) gene, rs9257691, in the MHC telomeric region. The OR provides "an internal depiction of our external world" through the capture of odorant molecules in the main OR system by several large families of G-protein coupled receptors (GPCR). These receptors transduce and chemosignals into the central nervous system (CNS). This SNP was chosen to identify its association with T1D. Interestingly, OR14J1C allele was significantly associated with T1D that seems to go with DRB1*0401, Χ(2)=10.9, p=0.0003. However, by fixing both genes of DR*0401-DQB1*0302, high risk, the association of T1D with OR14J1C still existed, Χ(2)=7.4, p=0.005. The occurrence of association of the OR14J1C allele with T1D patients with DRB1*401/DQB1*0302 is an independent risk for T1D. As an accumulative report suggests the role of OR in the pathogenesis of diabetic microvascular and other diabetic complications, undoubtedly, this haplotype specific alteration of T1D risk is an independent risk for the disease and can address the promising MHC-linked gene other than DR/DQ. Moreover, there is nothing to hinder for that this might be a signal that identifies the role of OR gene in the pathogenesis of T1D in patients who are prone to diabetic complications. Copyright © 2012. Published by Elsevier B.V.

  17. Neuronal nitric oxide synthase in the olfactory system of an adult teleost fish Oreochromis mossambicus.

    Science.gov (United States)

    Singru, Praful S; Sakharkar, Amul J; Subhedar, Nishikant

    2003-07-11

    The aim of the present study is to explore the distribution of nitric oxide synthase in the olfactory system of an adult teleost, Oreochromis mossambicus using neuronal nitric oxide synthase (nNOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry methods. Intense nNOS immunoreactivity was noticed in several olfactory receptor neurons (ORNs), in their axonal extensions over the olfactory nerve and in some basal cells of the olfactory epithelium. nNOS containing fascicles of the ORNs enter the bulb from its rostral pole, spread in the olfactory nerve layer in the periphery of the bulb and display massive innervation of the olfactory glomeruli. Unilateral ablation of the olfactory organ resulted in dramatic loss of nNOS immunoreactivity in the olfactory nerve layer of the ipsilateral bulb. In the olfactory bulb of intact fish, some granule cells showed intense immunoreactivity; dendrites arising from the granule cells could be traced to the glomerular layer. Of particular interest is the occurrence of nNOS immunoreactivity in the ganglion cells of the nervus terminalis. nNOS containing fibers were also encountered in the medial olfactory tracts as they extend to the telencephalon. The NADPHd staining generally coincides with that of nNOS suggesting that it may serve as a marker for nNOS in the olfactory system of this fish. However, mismatch was encountered in the case of mitral cells, while all are nNOS-negative, few were NADPHd positive. The present study for the first time revealed the occurrence of nNOS immunoreactivity in the ORNs of an adult vertebrate and suggests a role for nitric oxide in the transduction of odor stimuli, regeneration of olfactory epithelium and processing of olfactory signals.

  18. In vitro function of the aryl hydrocarbon receptor predicts in vivo sensitivity of oviparous vertebrates to dioxin-like compounds

    Science.gov (United States)

    Differences in sensitivity to dioxin-like compounds (DLCs) among species and taxa presents a major challenge to ecological risk assessments. Activation of the aryl hydrocarbon receptor (AHR) regulates adverse effects associated with exposure to DLCs in vertebrates. Prior investig...

  19. Caffeine reverses age-related deficits in olfactory discrimination and social recognition memory in rats. Involvement of adenosine A1 and A2A receptors.

    Science.gov (United States)

    Prediger, Rui D S; Batista, Luciano C; Takahashi, Reinaldo N

    2005-06-01

    Caffeine, a non-selective adenosine receptor antagonist, has been suggested as a potential drug to counteract age-related cognitive decline since critical changes in adenosinergic neurotransmission occur with aging. In the present study, olfactory discrimination and short-term social memory of 3, 6, 12 and 18 month-old rats were assessed with the olfactory discrimination and social recognition tasks, respectively. The actions of caffeine (3.0, 10.0 and 30.0 mg/kg, i.p.), the A1 receptor antagonist DPCPX (1.0 and 3.0 mg/kg, i.p.) and the A2A receptor antagonist ZM241385 (0.5 and 1.0 mg/kg, i.p.) in relation to age-related effects on olfactory functions were also studied. The 12 and 18 month-old rats exhibited significantly impaired performance in both models, demonstrating deficits in their odor discrimination and in their ability to recognize a juvenile rat after a short period of time. Acute treatment with caffeine or ZM241385, but not with DPCPX, reversed these age-related olfactory deficits. The present results suggest the participation of adenosine receptors in the control of olfactory functions and confirm the potential of caffeine for the treatment of aged-related cognitive decline.

  20. Concomitant duplications of opioid peptide and receptor genes before the origin of jawed vertebrates.

    Directory of Open Access Journals (Sweden)

    Görel Sundström

    Full Text Available BACKGROUND: The opioid system is involved in reward and pain mechanisms and consists in mammals of four receptors and several peptides. The peptides are derived from four prepropeptide genes, PENK, PDYN, PNOC and POMC, encoding enkephalins, dynorphins, orphanin/nociceptin and beta-endorphin, respectively. Previously we have described how two rounds of genome doubling (2R before the origin of jawed vertebrates formed the receptor family. METHODOLOGY/PRINCIPAL FINDINGS: Opioid peptide gene family members were investigated using a combination of sequence-based phylogeny and chromosomal locations of the peptide genes in various vertebrates. Several adjacent gene families were investigated similarly. The results show that the ancestral peptide gene gave rise to two additional copies in the genome doublings. The fourth member was generated by a local gene duplication, as the genes encoding POMC and PNOC are located on the same chromosome in the chicken genome and all three teleost genomes that we have studied. A translocation has disrupted this synteny in mammals. The PDYN gene seems to have been lost in chicken, but not in zebra finch. Duplicates of some peptide genes have arisen in the teleost fishes. Within the prepropeptide precursors, peptides have been lost or gained in different lineages. CONCLUSIONS/SIGNIFICANCE: The ancestral peptide and receptor genes were located on the same chromosome and were thus duplicated concomitantly. However, subsequently genetic linkage has been lost. In conclusion, the system of opioid peptides and receptors was largely formed by the genome doublings that took place early in vertebrate evolution.

  1. Molecular cloning, functional characterization, and evolutionary analysis of vitamin D receptors isolated from basal vertebrates.

    Directory of Open Access Journals (Sweden)

    Erin M Kollitz

    Full Text Available The vertebrate genome is a result of two rapid and successive rounds of whole genome duplication, referred to as 1R and 2R. Furthermore, teleost fish have undergone a third whole genome duplication (3R specific to their lineage, resulting in the retention of multiple gene paralogs. The more recent 3R event in teleosts provides a unique opportunity to gain insight into how genes evolve through specific evolutionary processes. In this study we compare molecular activities of vitamin D receptors (VDR from basal species that diverged at key points in vertebrate evolution in order to infer derived and ancestral VDR functions of teleost paralogs. Species include the sea lamprey (Petromyzon marinus, a 1R jawless fish; the little skate (Leucoraja erinacea, a cartilaginous fish that diverged after the 2R event; and the Senegal bichir (Polypterus senegalus, a primitive 2R ray-finned fish. Saturation binding assays and gel mobility shift assays demonstrate high affinity ligand binding and classic DNA binding characteristics of VDR has been conserved across vertebrate evolution. Concentration response curves in transient transfection assays reveal EC50 values in the low nanomolar range, however maximum transactivational efficacy varies significantly between receptor orthologs. Protein-protein interactions were investigated using co-transfection, mammalian 2-hybrid assays, and mutations of coregulator activation domains. We then combined these results with our previous study of VDR paralogs from 3R teleosts into a bioinformatics analysis. Our results suggest that 1, 25D3 acts as a partial agonist in basal species. Furthermore, our bioinformatics analysis suggests that functional differences between VDR orthologs and paralogs are influenced by differential protein interactions with essential coregulator proteins. We speculate that we may be observing a change in the pharmacodynamics relationship between VDR and 1, 25D3 throughout vertebrate evolution that may

  2. Functional characterization of a mouse testicular olfactory receptor and its role in chemosensing and in regulation of sperm motility.

    Science.gov (United States)

    Fukuda, Nanaho; Yomogida, Kentaro; Okabe, Masaru; Touhara, Kazushige

    2004-11-15

    Although a subset of the olfactory receptor (OR) gene family is expressed in testis, neither their developmental profile nor their physiological functions have been fully characterized. Here, we show that MOR23 (a mouse OR expressed in the olfactory epithelium and testis) functions as a chemosensing receptor in mouse germ cells. In situ hybridization showed that MOR23 was expressed in round spermatids during stages VI-VIII of spermatogenesis. Lyral, a cognate ligand of MOR23, caused an increase in intracellular Ca2+ in a fraction of spermatogenic cells and spermatozoa. We also generated transgenic mice that express high levels of MOR23 in the testis and examined the response of their germ cells to lyral. The results provided evidence that lyral-induced Ca2+ increases were indeed mediated by MOR23. In a sperm accumulation assay, spermatozoa migrated towards an increasing gradient of lyral. Tracking and sperm flagellar analyses suggest that Ca2+ increases caused by MOR23 activation lead to modulation of flagellar configuration, resulting in chemotaxis. By contrast, a gradient of a cAMP analog or K8.6 solution, which elicit Ca2+ influx in spermatozoa, did not cause sperm accumulation, indicating that chemosensing and regulation of sperm motility was due to an OR-mediated local Ca2+ increase. The present studies indicate that mouse testicular ORs might play a role in chemoreception during sperm-egg communication and thereby regulate fertilization.

  3. Hierarchical axon targeting of Drosophila olfactory receptor neurons specified by the proneural transcription factors Atonal and Amos.

    Science.gov (United States)

    Okumura, Misako; Kato, Tomoko; Miura, Masayuki; Chihara, Takahiro

    2016-01-01

    Sensory information is spatially represented in the brain to form a neural map. It has been suggested that axon-axon interactions are important for neural map formation; however, the underlying mechanisms are not fully understood. We used the Drosophila antennal lobe, the first olfactory center in the brain, as a model for studying neural map formation. Olfactory receptor neurons (ORNs) expressing the same odorant receptor target their axons to a single glomerulus out of approximately 50 glomeruli in the antennal lobe. Previous studies have showed that the axons of Atonal ORNs, specified by Atonal, a basic helix-loop-helix (bHLH) transcription factor, pioneer antennal lobe formation; however, the details remain to be elucidated. Here, we show that genetic ablation of Atonal ORNs affects antennal lobe structure and axon targeting of Amos ORNs, another type of ORN specified by the bHLH transcription factor Amos. During development, Atonal ORNs reach the antennal lobe and form the axon commissure before Amos ORNs. We also found that N-cadherin knockdown specifically in Atonal ORNs disrupts the glomerular boundary in the whole antennal lobe. Our results suggest that Atonal ORNs function as pioneer axons. Thus, correct axon targeting of Atonal ORNs is essential for formation of the whole antennal lobe. © 2015 The Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  4. A Testosterone Metabolite 19-Hydroxyandrostenedione Induces Neuroendocrine Trans-Differentiation of Prostate Cancer Cells via an Ectopic Olfactory Receptor

    Directory of Open Access Journals (Sweden)

    Tatjana Abaffy

    2018-05-01

    Full Text Available Olfactory receptor OR51E2, also known as a Prostate Specific G-Protein Receptor, is highly expressed in prostate cancer but its function is not well understood. Through in silico and in vitro analyses, we identified 24 agonists and 1 antagonist for this receptor. We detected that agonist 19-hydroxyandrostenedione, a product of the aromatase reaction, is endogenously produced upon receptor activation. We characterized the effects of receptor activation on metabolism using a prostate cancer cell line and demonstrated decreased intracellular anabolic signals and cell viability, induction of cell cycle arrest, and increased expression of neuronal markers. Furthermore, upregulation of neuron-specific enolase by agonist treatment was abolished in OR51E2-KO cells. The results of our study suggest that OR51E2 activation results in neuroendocrine trans-differentiation. These findings reveal a new role for OR51E2 and establish this G-protein coupled receptor as a novel therapeutic target in the treatment of prostate cancer.

  5. Background odour induces adaptation and sensitization of olfactory receptors in the antennae of houseflies

    NARCIS (Netherlands)

    Kelling, F.J; Ialenti, F.; den Otter, C.J

    The presence of background odour was found to have a small but significant effect on the sensitivity of the antennal olfactory system of houseflies, Musca domestica Linnaeus (Diptera: Muscidae), to new pulses of odour. We show that cross-adaptation and cross-sensitization between a background odour

  6. Functional promiscuity in a mammalian chemosensory system: extensive expression of vomeronasal receptors in the main olfactory epithelium of mouse lemurs

    Directory of Open Access Journals (Sweden)

    Philipp eHohenbrink

    2014-09-01

    Full Text Available The vomeronasal organ (VNO is functional in most terrestrial mammals, though progressively reduced in the primate lineage, and is used for intraspecific communication and predator recognition. Vomeronasal receptor (VR genes comprise two families of chemosensory genes (V1R and V2R that have been considered to be specific for the VNO. However, recently a large number of VRs were reported to be expressed in the main olfactory epithelium (MOE of mice, but there is little knowledge of the expression of these genes outside of rodents. To explore the function of VR genes in mammalian evolution, we analyzed and compared the expression of 64 V1R and 2 V2R genes in the VNO and the MOE of the grey mouse lemur (Microcebus murinus, the primate with the largest known VR repertoire. We furthermore compared expression patterns in adults of both sexes and seasons, and in an infant. A large proportion (83% – 97% of the VR loci was expressed in the VNO of all individuals. The repertoire in the infant was as rich as in adults, indicating reliance on olfactory communication from early postnatal development onwards. In concordance with mice, we also detected extensive expression of VRs in the MOE, with proportions of expressed loci in individuals ranging from 29% to 45%. TRPC2, which encodes a channel protein crucial for signal transduction via VRs, was co-expressed in the MOE in all individuals indicating likely functionality of expressed VR genes in the MOE. In summary, the large VR repertoire in mouse lemurs seems to be highly functional. Given the differences in the neural pathways of MOE and VNO signals, which project to higher cortical brain centers or the limbic system, respectively, this raises the intriguing possibility that the evolution of MOE-expression of VRs enabled mouse lemurs to adaptively diversify the processing of VR-encoded olfactory information.

  7. Projections from the posterolateral olfactory amygdala to the ventral striatum: neural basis for reinforcing properties of chemical stimuli

    Directory of Open Access Journals (Sweden)

    Lanuza Enrique

    2007-11-01

    Full Text Available Abstract Background Vertebrates sense chemical stimuli through the olfactory receptor neurons whose axons project to the main olfactory bulb. The main projections of the olfactory bulb are directed to the olfactory cortex and olfactory amygdala (the anterior and posterolateral cortical amygdalae. The posterolateral cortical amygdaloid nucleus mainly projects to other amygdaloid nuclei; other seemingly minor outputs are directed to the ventral striatum, in particular to the olfactory tubercle and the islands of Calleja. Results Although the olfactory projections have been previously described in the literature, injection of dextran-amines into the rat main olfactory bulb was performed with the aim of delimiting the olfactory tubercle and posterolateral cortical amygdaloid nucleus in our own material. Injection of dextran-amines into the posterolateral cortical amygdaloid nucleus of rats resulted in anterograde labeling in the ventral striatum, in particular in the core of the nucleus accumbens, and in the medial olfactory tubercle including some islands of Calleja and the cell bridges across the ventral pallidum. Injections of Fluoro-Gold into the ventral striatum were performed to allow retrograde confirmation of these projections. Conclusion The present results extend previous descriptions of the posterolateral cortical amygdaloid nucleus efferent projections, which are mainly directed to the core of the nucleus accumbens and the medial olfactory tubercle. Our data indicate that the projection to the core of the nucleus accumbens arises from layer III; the projection to the olfactory tubercle arises from layer II and is much more robust than previously thought. This latter projection is directed to the medial olfactory tubercle including the corresponding islands of Calleja, an area recently described as critical node for the neural circuit of addiction to some stimulant drugs of abuse.

  8. Neuropeptide S ameliorates olfactory spatial memory impairment induced by scopolamine and MK801 through activation of cognate receptor-expressing neurons in the subiculum complex.

    Science.gov (United States)

    Shao, Yu-Feng; Wang, Can; Xie, Jun-Fan; Kong, Xiang-Pan; Xin, Le; Dong, Chao-Yu; Li, Jing; Ren, Wen-Ting; Hou, Yi-Ping

    2016-07-01

    Our previous studies have demonstrated that neuropeptide S (NPS), via selective activation of the neurons bearing NPS receptor (NPSR) in the olfactory cortex, facilitates olfactory function. High level expression of NPSR mRNA in the subiculum complex of hippocampal formation suggests that NPS-NPSR system might be involved in the regulation of olfactory spatial memory. The present study was undertaken to investigate effects of NPS on the scopolamine- or MK801-induced impairment of olfactory spatial memory using computer-assisted 4-hole-board spatial memory test, and by monitoring Fos expression in the subiculum complex in mice. In addition, dual-immunofluorescence microscopy was employed to identify NPS-induced Fos-immunereactive (-ir) neurons that also bear NPSR. Intracerebroventricular administration of NPS (0.5 nmol) significantly increased the number of visits to switched odorants in recall trial in mice suffering from odor-discriminating inability induced by scopolamine, a selective muscarinic cholinergic receptor antagonist, or MK801, a N-methyl-D-aspartate receptor antagonist, after training trials. The improvement of olfactory spatial memory by NPS was abolished by the NPSR antagonist [D-Val(5)]NPS (40 nmol). Ex vivo c-Fos and NPSR immunohistochemistry revealed that, as compared with vehicle-treated mice, NPS markedly enhanced Fos expression in the subiculum complex encompassing the subiculum (S), presubiculum (PrS) and parasubiculum (PaS). The percentages of Fos-ir neurons that also express NPSR were 91.3, 86.5 and 90.0 % in the S, PrS and PaS, respectively. The present findings demonstrate that NPS, via selective activation of the neurons bearing NPSR in the subiculum complex, ameliorates olfactory spatial memory impairment induced by scopolamine and MK801 in mice.

  9. Evaluating the interactions of vertebrate receptors with persistent pollutants and antifouling pesticides using recombinant yeast assays

    Energy Technology Data Exchange (ETDEWEB)

    Noguerol, Tania-Noelia; Boronat, Susanna; Casado, Marta; Pina, Benjamin [Institut de Biologia Molecular de Barcelona, CSIC, Department of Molecular Biology, Barcelona (Spain); Raldua, Demetrio [Laboratory of Environmental Toxicology, INTEXTER -UP, Terrassa (Spain); Barcelo, Damia [IIQAB-CSIC, Department of Environmental Chemistry, Barcelona (Spain)

    2006-07-15

    The development of in vitro methods for screening potentially harmful biological activities of new compounds is an extremely important way to increase not only their intrinsic environmental safety, but also the public perception of the safety standards associated with them. In this work we use two yeast systems to test the ability of different chemicals to bind and activate two vertebrate receptors which are intimately related to adverse biological effects of pollution in exposed fauna: the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR). The panel of compounds analysed here includes well-known pollutants, like PCBs, pp'-DDT and hexachlorobenzene, together with the less-known, emerging putative pollutants, such as Sea-Nine, Irgarol and diuron. Results show the ability of some of these compounds to interact with one or both receptors, provide hints about the relationship between structure and activity, and suggest mechanistic explanations for the biological activities already described in whole-animal experiments. In addition, we show that AhR may have an intrinsic ligand promiscuity comparable to that of ER, a feature not fully appreciated in the past due to the technical difficulties involved with testing highly lipophilic substances in yeast-based assays. (orig.)

  10. The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development

    Science.gov (United States)

    Reissmann, Eva; Jörnvall, Henrik; Blokzijl, Andries; Andersson, Olov; Chang, Chenbei; Minchiotti, Gabriella; Persico, M. Graziella; Ibáñez, Carlos F.; Brivanlou, Ali H.

    2001-01-01

    Nodal proteins have crucial roles in mesendoderm formation and left–right patterning during vertebrate development. The molecular mechanisms of signal transduction by Nodal and related ligands, however, are not fully understood. In this paper, we present biochemical and functional evidence that the orphan type I serine/threonine kinase receptor ALK7 acts as a receptor for mouse Nodal and Xenopus Nodal-related 1 (Xnr1). Receptor reconstitution experiments indicate that ALK7 collaborates with ActRIIB to confer responsiveness to Xnr1 and Nodal. Both receptors can independently bind Xnr1. In addition, Cripto, an extracellular protein genetically implicated in Nodal signaling, can independently interact with both Xnr1 and ALK7, and its expression greatly enhances the ability of ALK7 and ActRIIB to respond to Nodal ligands. The Activin receptor ALK4 is also able to mediate Nodal signaling but only in the presence of Cripto, with which it can also interact directly. A constitutively activated form of ALK7 mimics the mesendoderm-inducing activity of Xnr1 in Xenopus embryos, whereas a dominant-negative ALK7 specifically blocks the activities of Nodal and Xnr1 but has little effect on other related ligands. In contrast, a dominant-negative ALK4 blocks all mesoderm-inducing ligands tested, including Nodal, Xnr1, Xnr2, Xnr4, and Activin. In agreement with a role in Nodal signaling, ALK7 mRNA is localized to the ectodermal and organizer regions of Xenopus gastrula embryos and is expressed during early stages of mouse embryonic development. Therefore, our results indicate that both ALK4 and ALK7 can mediate signal transduction by Nodal proteins, although ALK7 appears to be a receptor more specifically dedicated to Nodal signaling. PMID:11485994

  11. Fish genomes provide novel insights into the evolution of vertebrate secretin receptors and their ligand.

    Science.gov (United States)

    Cardoso, João C R; Félix, Rute C; Trindade, Marlene; Power, Deborah M

    2014-12-01

    The secretin receptor (SCTR) is a member of Class 2 subfamily B1 GPCRs and part of the PAC1/VPAC receptor subfamily. This receptor has long been known in mammals but has only recently been identified in other vertebrates including teleosts, from which it was previously considered to be absent. The ligand for SCTR in mammals is secretin (SCT), an important gastrointestinal peptide, which in teleosts has not yet been isolated, or the gene identified. This study revises the evolutionary model previously proposed for the secretin-GPCRs in metazoan by analysing in detail the fishes, the most successful of the extant vertebrates. All the Actinopterygii genomes analysed and the Chondrichthyes and Sarcopterygii fish possess a SCTR gene that shares conserved sequence, structure and synteny with the tetrapod homologue. Phylogenetic clustering and gene environment comparisons revealed that fish and tetrapod SCTR shared a common origin and diverged early from the PAC1/VPAC subfamily group. In teleosts SCTR duplicated as a result of the fish specific whole genome duplication but in all the teleost genomes analysed, with the exception of tilapia (Oreochromis niloticus), one of the duplicates was lost. The function of SCTR in teleosts is unknown but quantitative PCR revealed that in both sea bass (Dicentrarchus labrax) and tilapia (Oreochromis mossambicus) transcript abundance is high in the gastrointestinal tract suggesting it may intervene in similar processes to those in mammals. In contrast, no gene encoding the ligand SCT was identified in the ray-finned fishes (Actinopterygii) although it was present in the coelacanth (lobe finned fish, Sarcopterygii) and in the elephant shark (holocephalian). The genes in linkage with SCT in tetrapods and coelacanth were also identified in ray-finned fishes supporting the idea that it was lost from their genome. At present SCTR remains an orphan receptor in ray-finned fishes and it will be of interest in the future to establish why SCT was

  12. Three neuropeptide Y receptor genes in the spiny dogfish, Squalus acanthias, support en bloc duplications in early vertebrate evolution.

    Science.gov (United States)

    Salaneck, Erik; Ardell, David H; Larson, Earl T; Larhammar, Dan

    2003-08-01

    It has been debated whether the increase in gene number during early vertebrate evolution was due to multiple independent gene duplications or synchronous duplications of many genes. We describe here the cloning of three neuropeptide Y (NPY) receptor genes belonging to the Y1 subfamily in the spiny dogfish, Squalus acanthias, a cartilaginous fish. The three genes are orthologs of the mammalian subtypes Y1, Y4, and Y6, which are located in paralogous gene regions on different chromosomes in mammals. Thus, these genes arose by duplications of a chromosome region before the radiation of gnathostomes (jawed vertebrates). Estimates of duplication times from linearized trees together with evidence from other gene families supports two rounds of chromosome duplications or tetraploidizations early in vertebrate evolution. The anatomical distribution of mRNA was determined by reverse-transcriptase PCR and was found to differ from mammals, suggesting differential functional diversification of the new gene copies during the radiation of the vertebrate classes.

  13. Molecular Characterization and Differential Expression of an Olfactory Receptor Gene Family in the White-Backed Planthopper Sogatella furcifera Based on Transcriptome Analysis.

    Directory of Open Access Journals (Sweden)

    Ming He

    Full Text Available The white-backed planthopper, Sogatella furcifera, a notorious rice pest in Asia, employs host plant volatiles as cues for host location. In insects, odor detection is mediated by two types of olfactory receptors: odorant receptors (ORs and ionotropic receptors (IRs. In this study, we identified 63 SfurORs and 14 SfurIRs in S. furcifera based on sequences obtained from the head transcriptome and bioinformatics analysis. The motif-pattern of 130 hemiptera ORs indicated an apparent differentiation in this order. Phylogenetic trees of the ORs and IRs were constructed using neighbor-joining estimates. Most of the ORs had orthologous genes, but a specific OR clade was identified in S. furcifera, which suggests that these ORs may have specific olfactory functions in this species. Our results provide a basis for further investigations of how S. furcifera coordinates its olfactory receptor genes with its plant hosts, thereby providing a foundation for novel pest management approaches based on these genes.

  14. Aversive odorant causing appetite decrease downregulates tyrosine decarboxylase gene expression in the olfactory receptor neuron of the blowfly, Phormia regina

    Science.gov (United States)

    Ishida, Yuko; Ozaki, Mamiko

    2012-01-01

    In the blowfly Phormia regina, exposure to d-limonene for 5 days during feeding inhibits proboscis extension reflex behavior due to decreasing tyramine (TA) titer in the brain. TA is synthesized by tyrosine decarboxylase (Tdc) and catalyzed into octopamine (OA) by TA ß-hydroxylase (Tbh). To address the mechanisms of TA titer regulation in the blowfly, we cloned Tdc and Tbh cDNAs from P. regina (PregTdc and PregTbh). The deduced amino acid sequences of both proteins showed high identity to those of the corresponding proteins from Drosophila melanogaster at the amino acid level. PregTdc was expressed in the antenna, labellum, and tarsus whereas PregTbh was expressed in the head, indicating that TA is mainly synthesized in the sensory organs whereas OA is primarily synthesized in the brain. d-Limonene exposure significantly decreased PregTdc expression in the antenna but not in the labellum and the tarsus, indicating that PregTdc expressed in the antenna is responsible for decreasing TA titer. PregTdc-like immunoreactive material was localized in the thin-walled sensillum. In contrast, the OA/TA receptor (PregOAR/TAR) was localized to the thick-walled sensillum. The results indicated that d-limonene inhibits PregTdc expression in the olfactory receptor neurons in the thin-walled sensilla, likely resulting in reduced TA levels in the receptor neurons in the antenna. TA may be transferred from the receptor neuron to the specific synaptic junction in the antennal lobe of the brain through the projection neurons and play a role in conveying the aversive odorant information to the projection and local neurons.

  15. Vertebrate scavenger receptor class B member 2 (SCARB2: comparative studies of a major lysosomal membrane glycoprotein

    Directory of Open Access Journals (Sweden)

    Roger Stephen Holmes

    2012-06-01

    Full Text Available Scavenger receptor class B member 2 (SCARB2 (also LIMP-2, CD36L2 or LGP85 is a major lysosomal membrane glycoprotein involved in endosomal and lysosomal biogenesis and maintenance. SCARB2 acts as a receptor for the lysosomal mannose-6-phosphate independent targeting of β-glucuronidase and enterovirus 71 and influences Parkinson’s disease and epilepsy. Genetic deficiency of this protein causes deafness and peripheral neuropathy in mice as well as myoclonic epilepsy and nephrotic syndrome in humans. Comparative SCARB2 amino acid sequences and structures and SCARB2 gene locations were examined using data from several vertebrate genome projects. Vertebrate SCARB2 sequences shared 43-100% identity as compared with 30-36% sequence identities with other CD36-like superfamily members, SCARB1 and CD36. At least 10 N-glycosylation sites were conserved among most vertebrate SCARB2 proteins examined. Sequence alignments, key amino acid residues and conserved predicted secondary structures were examined, including cytoplasmic, transmembrane and external lysosomal membrane sequences: cysteine disulfide residues, thrombospondin (THP1 binding sites and 16 proline and 20 glycine conserved residues, which may contribute to short loop formation within the exomembrane SCARB2 sequences. Vertebrate SCARB2 genes contained 12 coding exons. The human SCARB2 gene contained a CpG island (CpG100, ten microRNA-binding sites and several transcription factor binding sites (including PPARA which may contribute to a higher level (2.4 times average of gene expression. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate SCARB2 gene with vertebrate SCARB1 and CD36 genes. These suggested that SCARB2 originated from duplications of the CD36 gene in an ancestral genome forming three vertebrate CD36 gene family members: SCARB1, SCARB2 and CD36.

  16. Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: Tales from Testing the Vibration Theory

    OpenAIRE

    Paoli, M.; M?nch, D.; Haase, A.; Skoulakis, E.; Turin, L.; Galizia, C. G.

    2017-01-01

    Several studies have attempted to test the vibrational hypothesis of odorant receptor activation in behavioral and physiological studies using deuterated compounds as odorants. The results have been mixed. Here, we attempted to test how deuterated compounds activate odorant receptors using calcium imaging of the fruit fly antennal lobe. We found specific activation of one area of the antennal lobe corresponding to inputs from a specific receptor. However, upon more detailed analysis, we disco...

  17. Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: a patch clamp analysis in gene-targeted mice.

    Science.gov (United States)

    Grosmaitre, Xavier; Vassalli, Anne; Mombaerts, Peter; Shepherd, Gordon M; Ma, Minghong

    2006-02-07

    A glomerulus in the mammalian olfactory bulb receives axonal inputs from olfactory sensory neurons (OSNs) that express the same odorant receptor (OR). Glomeruli are generally thought to represent functional units of olfactory coding, but there are no data on the electrophysiological properties of OSNs that express the same endogenous OR. Here, using patch clamp recordings in an intact epithelial preparation, we directly measured the transduction currents and receptor potentials from the dendritic knobs of mouse OSNs that express the odorant receptor MOR23 along with the green fluorescent protein. All of the 53 cells examined responded to lyral, a known ligand for MOR23. There were profound differences in response kinetics, particularly in the deactivation phase. The cells were very sensitive to lyral, with some cells responding to as little as 10 nM. The dynamic range was unexpectedly broad, with threshold and saturation in individual cells often covering three log units of lyral concentration. The potential causes and biological significance of this cellular heterogeneity are discussed. Patch clamp recording from OSNs that express a defined OR provides a powerful approach to investigate the sensory inputs to individual glomeruli.

  18. Transient reversal of olfactory preference following castration in male rats: Implication for estrogen receptor involvement.

    Science.gov (United States)

    Xiao, Kai; Chiba, Atsuhiko; Sakuma, Yasuo; Kondo, Yasuhiko

    2015-12-01

    We examined the effects of the sex steroid milieu on sexual odor preference of sexually-experienced male rats using an alternate choice paradigm after endocrine manipulations. Gonadally intact (GI) males showed a male typical preference, i.e. spent longer time sniffing estrous females than males or ovariectomized females. At 1-2 weeks after orchidectomy (ORx), the males exhibited a transient preference for sexually vigorous males, a female typical preference pattern, followed by a total loss of preference after 4 weeks. Subcutaneous implantation of a Silastic capsule containing formestane (4-OHA), an aromatase inhibitor, had no effect on the preference of gonadally intact rats, but successfully prevented the emergence of the female typical preference after ORx. Capsules containing testosterone (T), dihydrotestosterone (DHT), or estradiol benzoate (EB), but not those with cholesterol (CH), restored masculine typical preference in ORx males at 2 weeks after the placement. The feminine preference for males was observed at 2-3 weeks after removal of T or EB capsules, but not by the removal of DHT and CH capsules. The results suggest that either exogenous androgen or estrogen maintains the masculine typical odor preference. Estrogen itself or produced through aromatization of circulating T, induces a transient feminine typical preference at a certain decreased titer during its disappearance from the circulation. Estrogen at different titers might determine appearance of masculine or feminine typical olfactory preference in adult ORx rats. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Comparative studies of vertebrate scavenger receptor class B type 1: a high-density lipoprotein binding protein

    Directory of Open Access Journals (Sweden)

    Holmes RS

    2012-06-01

    Full Text Available Roger S Holmes,1,2 Laura A Cox11Department of Genetics and Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA; 2School of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland, AustraliaAbstract: Scavenger receptor class B type 1 protein (SCARB1 plays an essential role in cholesterol homeostasis and functions in binding high density lipoprotein cholesterol (HDL in liver and other tissues of the body. SCARB1 also functions in lymphocyte homeostasis and in the uptake of hepatitis C virus (HCV by the liver. A genetic deficiency of this protein results in autoimmune disorders and significant changes in blood cholesterol phenotype. Comparative SCARB1 amino acid sequences and structures and SCARB1 gene locations were examined using data from several vertebrate genome projects. Vertebrate SCARB1 sequences shared 50%–99% identity as compared with 28%–31% sequence identities with other CD36-like superfamily members, ie, SCARB2 and SCARB3 (also called CD36. At least eight N-glycosylation sites were conserved among most of the vertebrate SCARB1 proteins examined. Sequence alignments, key amino acid residues, and conserved predicted secondary structures were also studied, including: cytoplasmic, transmembrane, and exoplasmic sequences; conserved N-terminal and C-terminal transmembrane glycines which participate in oligomer formation; conserved cystine disulfides and a free SH residue which participates in lipid transport; carboxyl terminal PDZ-binding domain sequences (Ala507-Arg/Lys508-Leu509; and 30 conserved proline and 18 conserved glycine residues, which may contribute to short loop formation within the exoplasmic HDL-binding sequence. Vertebrate SCARB1 genes usually contained 12 coding exons. The human SCARB1 gene contained CpG islands, micro RNA binding sites, and several transcription factor binding sites (including PPARG which may contribute to the high level (13.7 times

  20. Potential ligand-binding residues in rat olfactory receptors identified by correlated mutation analysis

    Science.gov (United States)

    Singer, M. S.; Oliveira, L.; Vriend, G.; Shepherd, G. M.

    1995-01-01

    A family of G-protein-coupled receptors is believed to mediate the recognition of odor molecules. In order to identify potential ligand-binding residues, we have applied correlated mutation analysis to receptor sequences from the rat. This method identifies pairs of sequence positions where residues remain conserved or mutate in tandem, thereby suggesting structural or functional importance. The analysis supported molecular modeling studies in suggesting several residues in positions that were consistent with ligand-binding function. Two of these positions, dominated by histidine residues, may play important roles in ligand binding and could confer broad specificity to mammalian odor receptors. The presence of positive (overdominant) selection at some of the identified positions provides additional evidence for roles in ligand binding. Higher-order groups of correlated residues were also observed. Each group may interact with an individual ligand determinant, and combinations of these groups may provide a multi-dimensional mechanism for receptor diversity.

  1. Olfactory Information Processing in the Drosophila Antennal Lobe : Anything Goes?

    OpenAIRE

    Silbering, Ana F.; Okada, Ryuichi; Ito, Kei; Galizia, Cosmas Giovanni

    2008-01-01

    When an animal smells an odor, olfactory sensory neurons generate an activity pattern across olfactory glomeruli of the first sensory neuropil, the insect antennal lobe or the vertebrate olfactory bulb. Here, several networks of local neurons interact with sensory neurons and with output neurons-insect projection neurons, or vertebrate mitral/tufted cells. The extent and form of information processing taking place in these local networks has been subject of controversy. To investigate the ro...

  2. Cannabis Users Show Enhanced Expression of CB1-5HT2A Receptor Heteromers in Olfactory Neuroepithelium Cells.

    Science.gov (United States)

    Galindo, Liliana; Moreno, Estefanía; López-Armenta, Fernando; Guinart, Daniel; Cuenca-Royo, Aida; Izquierdo-Serra, Mercè; Xicota, Laura; Fernandez, Cristina; Menoyo, Esther; Fernández-Fernández, José M; Benítez-King, Gloria; Canela, Enric I; Casadó, Vicent; Pérez, Víctor; de la Torre, Rafael; Robledo, Patricia

    2018-01-02

    Cannabinoid CB1 receptors (CB 1 R) and serotonergic 2A receptors (5HT 2A R) form heteromers in the brain of mice where they mediate the cognitive deficits produced by delta-9-tetrahydrocannabinol. However, it is still unknown whether the expression of this heterodimer is modulated by chronic cannabis use in humans. In this study, we investigated the expression levels and functionality of CB 1 R-5HT 2A R heteromers in human olfactory neuroepithelium (ON) cells of cannabis users and control subjects, and determined their molecular characteristics through adenylate cyclase and the ERK 1/2 pathway signaling studies. We also assessed whether heteromer expression levels correlated with cannabis consumption and cognitive performance in neuropsychological tests. ON cells from controls and cannabis users expressed neuronal markers such as βIII-tubulin and nestin, displayed similar expression levels of genes related to cellular self-renewal, stem cell differentiation, and generation of neural crest cells, and showed comparable Na + currents in patch clamp recordings. Interestingly, CB 1 R-5HT 2A R heteromer expression was significantly increased in cannabis users and positively correlated with the amount of cannabis consumed, and negatively with age of onset of cannabis use. In addition, a negative correlation was found between heteromer expression levels and attention and working memory performance in cannabis users and control subjects. Our findings suggest that cannabis consumption regulates the formation of CB 1 R-5HT 2A R heteromers, and may have a key role in cognitive processing. These heterodimers could be potential new targets to develop treatment alternatives for cognitive impairments.

  3. Existence of multiple receptors in single neurons: responses of single bullfrog olfactory neurons to many cAMP-dependent and independent odorants.

    Science.gov (United States)

    Kashiwayanagi, M; Shimano, K; Kurihara, K

    1996-11-04

    The responses of single bullfrog olfactory neurons to various odorants were measured with the whole-cell patch clamp which offers direct information on cellular events and with the ciliary recording technique to obtain stable quantitative data from many neurons. A large portion of single olfactory neurons (about 64% and 79% in the whole-cell recording and in the ciliary recording, respectively) responded to many odorants with quite diverse molecular structures, including both odorants previously indicated to be cAMP-dependent (increasing) and independent odorants. One odorant elicited a response in many cells; e.g. hedione and citralva elicited the response in 100% and 92% of total neurons examined with the ciliary recording technique. To confirm that a single neuron carries different receptors or transduction pathways, the cross-adaptation technique was applied to single neurons. Application of hedione to a single neuron after desensitization of the current in response to lyral or citralva induced an inward current with a similar magnitude to that applied alone. It was suggested that most single olfactory neurons carry multiple receptors and at least dual transduction pathways.

  4. Multiple thyrotropin β-subunit and thyrotropin receptor-related genes arose during vertebrate evolution.

    Directory of Open Access Journals (Sweden)

    Gersende Maugars

    Full Text Available Thyroid-stimulating hormone (TSH is composed of a specific β subunit and an α subunit that is shared with the two pituitary gonadotropins. The three β subunits derive from a common ancestral gene through two genome duplications (1R and 2R that took place before the radiation of vertebrates. Analysis of genomic data from phylogenetically relevant species allowed us to identify an additional Tshβ subunit-related gene that was generated through 2R. This gene, named Tshβ2, present in cartilaginous fish, little skate and elephant shark, and in early lobe-finned fish, coelacanth and lungfish, was lost in ray-finned fish and tetrapods. The absence of a second type of TSH receptor (Tshr gene in these species suggests that both TSHs act through the same receptor. A novel Tshβ sister gene, named Tshβ3, was generated through the third genomic duplication (3R that occurred early in the teleost lineage. Tshβ3 is present in most teleost groups but was lostin tedraodontiforms. The 3R also generated a second Tshr, named Tshrb. Interestingly, the new Tshrb was translocated from its original chromosomic position after the emergence of eels and was then maintained in its new position. Tshrb was lost in tetraodontiforms and in ostariophysians including zebrafish although the latter species have two TSHs, suggesting that TSHRb may be dispensable. The tissue distribution of duplicated Tshβs and Tshrs was studied in the European eel. The endocrine thyrotropic function in the eel would be essentially mediated by the classical Tshβ and Tshra, which are mainly expressed in the pituitary and thyroid, respectively. Tshβ3 and Tshrb showed a similar distribution pattern in the brain, pituitary, ovary and adipose tissue, suggesting a possible paracrine/autocrine mode of action in these non-thyroidal tissues. Further studies will be needed to determine the binding specificity of the two receptors and how these two TSH systems are interrelated.

  5. Odor-evoked inhibition of olfactory sensory neurons drives olfactory perception in Drosophila.

    Science.gov (United States)

    Cao, Li-Hui; Yang, Dong; Wu, Wei; Zeng, Xiankun; Jing, Bi-Yang; Li, Meng-Tong; Qin, Shanshan; Tang, Chao; Tu, Yuhai; Luo, Dong-Gen

    2017-11-07

    Inhibitory response occurs throughout the nervous system, including the peripheral olfactory system. While odor-evoked excitation in peripheral olfactory cells is known to encode odor information, the molecular mechanism and functional roles of odor-evoked inhibition remain largely unknown. Here, we examined Drosophila olfactory sensory neurons and found that inhibitory odors triggered outward receptor currents by reducing the constitutive activities of odorant receptors, inhibiting the basal spike firing in olfactory sensory neurons. Remarkably, this odor-evoked inhibition of olfactory sensory neurons elicited by itself a full range of olfactory behaviors from attraction to avoidance, as did odor-evoked olfactory sensory neuron excitation. These results indicated that peripheral inhibition is comparable to excitation in encoding sensory signals rather than merely regulating excitation. Furthermore, we demonstrated that a bidirectional code with both odor-evoked inhibition and excitation in single olfactory sensory neurons increases the odor-coding capacity, providing a means of efficient sensory encoding.

  6. Ryanodine receptors, a family of intracellular calcium ion channels, are expressed throughout early vertebrate development

    Directory of Open Access Journals (Sweden)

    Wu Houdini HT

    2011-12-01

    Full Text Available Abstract Background Calcium signals ([Ca2+]i direct many aspects of embryo development but their regulation is not well characterised. Ryanodine receptors (RyRs are a family of intracellular Ca2+ release channels that control the flux of Ca2+ from internal stores into the cytosol. RyRs are primarily known for their role in excitation-contraction coupling in adult striated muscle and ryr gene mutations are implicated in several human diseases. Current evidence suggests that RyRs do not have a major role to play prior to organogenesis but regulate tissue differentiation. Findings The sequences of the five zebrafish ryr genes were confirmed, their evolutionary relationship established and the primary sequences compared to other vertebrates, including humans. RyRs are differentially expressed in slow (ryr1a, fast (ryr3 and both types (ryr1b of developing skeletal muscle. There are two ryr2 genes (ryr2a and ryr2b which are expressed exclusively in developing CNS and cardiac tissue, respectively. In addition, ryr3 and ryr2a mRNA is detectable in the initial stages of development, prior to embryonic axis formation. Conclusions Our work reveals that zebrafish ryr genes are differentially expressed throughout the developing embryo from cleavage onwards. The data suggests that RyR-regulated Ca2+ signals are associated with several aspects of embryonic development, from organogenesis through to the differentiation of the musculoskeletal, cardiovascular and nervous system. These studies will facilitate further work to explore the developmental function of RyRs in each of these tissue types.

  7. Neuropeptide Y enhances olfactory mucosa responses to odorant in hungry rats.

    Science.gov (United States)

    Negroni, Julia; Meunier, Nicolas; Monnerie, Régine; Salesse, Roland; Baly, Christine; Caillol, Monique; Congar, Patrice

    2012-01-01

    Neuropeptide Y (NPY) plays an important role in regulating appetite and hunger in vertebrates. In the hypothalamus, NPY stimulates food intake under the control of the nutritional status. Previous studies have shown the presence of NPY and receptors in rodent olfactory system, and suggested a neuroproliferative role. Interestingly, NPY was also shown to directly modulate olfactory responses evoked by a food-related odorant in hungry axolotls. We have recently demonstrated that another nutritional cue, insulin, modulates the odorant responses of the rat olfactory mucosa (OM). Therefore, the aim of the present study was to investigate the potential effect of NPY on rat OM responses to odorants, in relation to the animal's nutritional state. We measured the potential NPY modulation of OM responses to odorant, using electro-olfactogram (EOG) recordings, in fed and fasted adult rats. NPY application significantly and transiently increased EOG amplitudes in fasted but not in fed rats. The effects of specific NPY-receptor agonists were similarly quantified, showing that NPY operated mainly through Y1 receptors. These receptors appeared as heterogeneously expressed by olfactory neurons in the OM, and western blot analysis showed that they were overexpressed in fasted rats. These data provide the first evidence that NPY modulates the initial events of odorant detection in the rat OM. Because this modulation depends on the nutritional status of the animal, and is ascribed to NPY, the most potent orexigenic peptide in the central nervous system, it evidences a strong supplementary physiological link between olfaction and nutritional processes.

  8. Induction of associative olfactory memory by targeted activation of single olfactory neurons in Drosophila larvae.

    Science.gov (United States)

    Honda, Takato; Lee, Chi-Yu; Yoshida-Kasikawa, Maki; Honjo, Ken; Furukubo-Tokunaga, Katsuo

    2014-04-25

    It has been postulated that associative memory is formed by at least two sets of external stimuli, CS and US, that are transmitted to the memory centers by distinctive conversing pathways. However, whether associative memory can be induced by the activation of only the olfactory CS and a biogenic amine-mediated US pathways remains to be elucidated. In this study, we substituted the reward signals with dTrpA1-mediated thermogenetic activation of octopaminergic neurons and the odor signals by ChR2-mediated optical activation of a specific class of olfactory neurons. We show that targeted activation of the olfactory receptor and the octopaminergic neurons is indeed sufficient for the formation of associative olfactory memory in the larval brain. We also show that targeted stimulation of only a single type of olfactory receptor neurons is sufficient to induce olfactory memory that is indistinguishable from natural memory induced by the activation of multiple olfactory receptor neurons.

  9. Olfactory receptors for a smell sensor: a comparative study of the electrical responses of rat I7 and human 17-40

    International Nuclear Information System (INIS)

    Alfinito, E; Millithaler, J-F; Reggiani, L

    2011-01-01

    In this paper, we explore the relevant electrical properties of two olfactory receptors (ORs), one from rat, OR I7, and the other from human, OR 17-40, which are of interest for the realization of smell nanobiosensors. The investigation compares existing experiments, coming from electrochemical impedance spectroscopy, with the theoretical expectations obtained from an impedance network protein analogue, recently developed. The changes in the response due to the sensing action of the proteins are correlated with the conformational change undergone by the single protein. The satisfactory agreement between theory and experiments points to a promising development of a new class of nanobiosensors based on the electrical properties of sensing proteins

  10. Pheromone binding proteins enhance the sensitivity of olfactory receptors to sex pheromones in Chilo suppressalis.

    Science.gov (United States)

    Chang, Hetan; Liu, Yang; Yang, Ting; Pelosi, Paolo; Dong, Shuanglin; Wang, Guirong

    2015-08-27

    Sexual communication in moths offers a simplified scenario to model and investigate insect sensory perception. Both PBPs (pheromone-binding proteins) and PRs (pheromone receptors) are involved in the detection of sex pheromones, but the interplay between them still remains largely unknown. In this study, we have measured the binding affinities of the four recombinant PBPs of Chilo suppressalis (CsupPBPs) to pheromone components and analogs and characterized the six PRs using the Xenopus oocytes expression system. Interestingly, when the responses of PRs were recorded in the presence of PBPs, we measured in several combinations a dramatic increase in signals as well as in sensitivity of such combined systems. Furthermore, the discrimination ability of appropriate combinations of PRs and PBPs was improved compared with the performance of PBPs or PRs alone. Besides further supporting a role of PBPs in the pheromone detection and discrimination, our data shows for the first time that appropriate combinations of PRs and PBPs improved the discrimination ability of PBPs or PRs alone. The variety of responses measured with different pairing of PBPs and PRs indicates the complexity of the olfaction system, which, even for the relatively simple task of detecting sex pheromones, utilises a highly sophisticated combinatorial approach.

  11. Olfactory dreams, olfactory interest, and imagery : Relationships to olfactory memory

    OpenAIRE

    Arshamian, Artin

    2007-01-01

    Existing evidence for olfactory imagery is mixed and mainly based on reports from hallucinations and volitional imagery. Using a questionnaire, Stevenson and Case (2005) showed that olfactory dreams provided a good source for olfactory imagery studies. This study applied an extended version of the same questionnaire and examined olfactory dreams and their relation to real-life experienced odors, volitional imagery, and olfactory interest. Results showed that olfactory dreams were similar to r...

  12. Evolution of vertebrate transient receptor potential vanilloid 3 channels: opposite temperature sensitivity between mammals and western clawed frogs.

    Directory of Open Access Journals (Sweden)

    Shigeru Saito

    2011-04-01

    Full Text Available Transient Receptor Potential (TRP channels serve as temperature receptors in a wide variety of animals and must have played crucial roles in thermal adaptation. The TRP vanilloid (TRPV subfamily contains several temperature receptors with different temperature sensitivities. The TRPV3 channel is known to be highly expressed in skin, where it is activated by warm temperatures and serves as a sensor to detect ambient temperatures near the body temperature of homeothermic animals such as mammals. Here we performed comprehensive comparative analyses of the TRPV subfamily in order to understand the evolutionary process; we identified novel TRPV genes and also characterized the evolutionary flexibility of TRPV3 during vertebrate evolution. We cloned the TRPV3 channel from the western clawed frog Xenopus tropicalis to understand the functional evolution of the TRPV3 channel. The amino acid sequences of the N- and C-terminal regions of the TRPV3 channel were highly diversified from those of other terrestrial vertebrate TRPV3 channels, although central portions were well conserved. In a heterologous expression system, several mammalian TRPV3 agonists did not activate the TRPV3 channel of the western clawed frog. Moreover, the frog TRPV3 channel did not respond to heat stimuli, instead it was activated by cold temperatures. Temperature thresholds for activation were about 16 °C, slightly below the lower temperature limit for the western clawed frog. Given that the TRPV3 channel is expressed in skin, its likely role is to detect noxious cold temperatures. Thus, the western clawed frog and mammals acquired opposite temperature sensitivity of the TRPV3 channel in order to detect environmental temperatures suitable for their respective species, indicating that temperature receptors can dynamically change properties to adapt to different thermal environments during evolution.

  13. Expression and evolutionary divergence of the non-conventional olfactory receptor in four species of fig wasp associated with one species of fig

    Directory of Open Access Journals (Sweden)

    Xiao Jinhua

    2009-02-01

    Full Text Available Abstract Background The interactions of fig wasps and their host figs provide a model for investigating co-evolution. Fig wasps have specialized morphological characters and lifestyles thought to be adaptations to living in the fig's syconium. Although these aspects of natural history are well documented, the genetic mechanism(s underlying these changes remain(s unknown. Fig wasp olfaction is the key to host-specificity. The Or83b gene class, an unusual member of olfactory receptor family, plays a critical role in enabling the function of conventional olfactory receptors. Four Or83b orthologous genes from one pollinator (PFW (Ceratosolen solmsi and three non-pollinator fig wasps (NPFWs (Apocrypta bakeri, Philotrypesis pilosa and Philotrypesis sp. associated with one species of fig (Ficus hispida can be used to better understand the molecular mechanism underlying the fig wasp's adaptation to its host. We made a comparison of spatial tissue-specific expression patterns and substitution rates of one orthologous gene in these fig wasps and sought evidence for selection pressures. Results A newly identified Or83b orthologous gene was named Or2. Expressions of Or2 were restricted to the heads of all wingless male fig wasps, which usually live in the dark cavity of a fig throughout their life cycle. However, expressions were widely detected in the antennae, legs and abdomens of all female fig wasps that fly from one fig to another for oviposition, and secondarily pollination. Weak expression was also observed in the thorax of PFWs. Compared with NPFWs, the Or2 gene in C. solmsi had an elevated rate of substitutions and lower codon usage. Analyses using Tajima's D, Fu and Li's D* and F* tests indicated a non-neutral pattern of nucleotide variation in all fig wasps. Unlike in NPFWs, this non-neutral pattern was also observed for synonymous sites of Or2 within PFWs. Conclusion The sex- and species-specific expression patterns of Or2 genes detected beyond

  14. The orphan G protein-coupled receptor 25 (GPR25) is activated by Apelin and Apela in non-mammalian vertebrates.

    Science.gov (United States)

    Zhang, Jiannan; Wan, Yiping; Fang, Chao; Chen, Junan; Ouyang, Wangan; Li, Juan; Wang, Yajun

    2018-06-22

    G protein-coupled receptor 25 (GPR25) is an orphan G protein-coupled receptor in vertebrates, that has been implicated to be associated with autoimmune diseases and regulate blood pressure in humans. However, the endogenous ligand of GPR25 remains unknown in vertebrates. Here, we reported that in non-mammalian vertebrates (zebrafish, spotted gars, and pigeons), GPR25 could be activated by Apelin and Apela peptides, which are also the two endogenous ligands of vertebrate Apelin receptor (APLNR). Using the pGL3-CRE-luciferase reporter assay and confocal microscopy, we first demonstrated that like APLNR, zebrafish GPR25 expressing in HEK293 cells could be effectively activated by zebrafish Apelin and Apela peptides, leading to the inhibition of forskolin-stimulated cAMP production and receptor internalization. Like zebrafish GPR25, pigeon and spotted gar GPR25 could also be activated by Apelin and Apela, and their activation could inhibit forskolin-induced cAMP accumulation. Interestingly, unlike zebrafish (/spotted gar/pigeon) GPR25, human GPR25 could not be activated by Apelin and Apela under the same experimental conditions. RNA-seq analysis further revealed that GPR25 is expressed in a variety of tissues, including the testes and intestine of zebrafish/spotted gars/humans, implying the potential roles of GPR25 signaling in many physiological processes in vertebrates. Taken together, our data not only provides the first proof that the orphan receptor GPR25 possesses two potential ligands 'Apelin and Apela' and its activation decreases intracellular cAMP levels in non-mammalian vertebrates, but also facilitates to unravel the physiological roles of GPR25 signaling in vertebrates. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Integration of bio-inspired, control-based visual and olfactory data for the detection of an elusive target

    Science.gov (United States)

    Duong, Tuan A.; Duong, Nghi; Le, Duong

    2017-01-01

    In this paper, we present an integration technique using a bio-inspired, control-based visual and olfactory receptor system to search for elusive targets in practical environments where the targets cannot be seen obviously by either sensory data. Bio-inspired Visual System is based on a modeling of extended visual pathway which consists of saccadic eye movements and visual pathway (vertebrate retina, lateral geniculate nucleus and visual cortex) to enable powerful target detections of noisy, partial, incomplete visual data. Olfactory receptor algorithm, namely spatial invariant independent component analysis, that was developed based on data of old factory receptor-electronic nose (enose) of Caltech, is adopted to enable the odorant target detection in an unknown environment. The integration of two systems is a vital approach and sets up a cornerstone for effective and low-cost of miniaturized UAVs or fly robots for future DOD and NASA missions, as well as for security systems in Internet of Things environments.

  16. The pre-vertebrate origins of neurogenic placodes.

    Science.gov (United States)

    Abitua, Philip Barron; Gainous, T Blair; Kaczmarczyk, Angela N; Winchell, Christopher J; Hudson, Clare; Kamata, Kaori; Nakagawa, Masashi; Tsuda, Motoyuki; Kusakabe, Takehiro G; Levine, Michael

    2015-08-27

    The sudden appearance of the neural crest and neurogenic placodes in early branching vertebrates has puzzled biologists for over a century. These embryonic tissues contribute to the development of the cranium and associated sensory organs, which were crucial for the evolution of the vertebrate "new head". A previous study suggests that rudimentary neural crest cells existed in ancestral chordates. However, the evolutionary origins of neurogenic placodes have remained obscure owing to a paucity of embryonic data from tunicates, the closest living relatives to those early vertebrates. Here we show that the tunicate Ciona intestinalis exhibits a proto-placodal ectoderm (PPE) that requires inhibition of bone morphogenetic protein (BMP) and expresses the key regulatory determinant Six1/2 and its co-factor Eya, a developmental process conserved across vertebrates. The Ciona PPE is shown to produce ciliated neurons that express genes for gonadotropin-releasing hormone (GnRH), a G-protein-coupled receptor for relaxin-3 (RXFP3) and a functional cyclic nucleotide-gated channel (CNGA), which suggests dual chemosensory and neurosecretory activities. These observations provide evidence that Ciona has a neurogenic proto-placode, which forms neurons that appear to be related to those derived from the olfactory placode and hypothalamic neurons of vertebrates. We discuss the possibility that the PPE-derived GnRH neurons of Ciona resemble an ancestral cell type, a progenitor to the complex neuronal circuit that integrates sensory information and neuroendocrine functions in vertebrates.

  17. Enhanced self-administration of the CB1 receptor agonist WIN55,212-2 in olfactory bulbectomized rats: evaluation of possible serotonergic and dopaminergic underlying mechanisms

    Directory of Open Access Journals (Sweden)

    Petra eAmchova

    2014-03-01

    Full Text Available Depression has been associated with drug consumption, including heavy or problematic cannabis use. According to an animal model of depression and substance use disorder comorbidity, we combined the olfactory bulbectomy model of depression with intravenous drug self-administration procedure to verify whether depressive-like rats displayed higher voluntary intake of the CB1 receptor agonist WIN55,212-2 (WIN, 12.5 µg/kg/infusion. To this aim, olfactory-bulbectomized (OBX and sham-operated (SHAM Lister Hooded rats were allowed to self-administer WIN by lever-pressing under a continuous (FR-1 schedule of reinforcement in 2h daily sessions. Data showed that both OBX and SHAM rats developed stable WIN intake; yet, responses in OBX were constantly higher than in SHAM rats soon after the first week of training. In addition, OBX rats took significantly longer to extinguish the drug-seeking behaviour after vehicle substitution. Acute pre-treatment with serotonin 5HT1B receptor agonist, CGS-12066B (2.5-10 mg/kg, did not significantly modify WIN intake in OBX and SHAM Lister Hooded rats. Furthermore, acute pre-treatment with CGS-12066B (10 and 15 mg/kg did not alter responses in parallel groups of OBX and SHAM Sprague Dawley rats self-administering methamphetamine under higher (FR-2 reinforcement schedule with nose-poking as operandum. Finally, dopamine levels in the nucleus accumbens of OBX rats did not increase in response to a WIN challenge, as in SHAM rats, indicating a dopaminergic dysfunction in bulbectomized rats. Altogether, our findings suggest that a depressive state may alter cannabinoid CB1 receptor agonist-induced brain reward function and that a dopaminergic rather than a 5-HT1B mechanism is likely to underlie enhanced WIN self-administration in OBX rats.

  18. The effect of NMDA-NR2B receptor subunit over-expression on olfactory memory task performance in the mouse.

    Science.gov (United States)

    White, Theresa L; Youngentob, Steven L

    2004-09-17

    The N-methyl-D-aspartate (NMDA) receptor in the forebrain is thought to modulate some forms of memory formation, with the NR2B subunit being particularly relevant to this process. Relative to wild-type mice, transgenic animals in which the NR2B subunit was over-expressed demonstrate superior memory in a number of behavioral tasks, including object recognition [Nature 401 (1999) 63]. The purpose of the present study was to explore the generality of such phenomena, interpreted as the effect of increasing NR2B expression on the retention of other types of sensory-related information. To accomplish this, we focused our evaluation on the highly salient sensory modality of olfaction. In the first experiment, mice performed both a novel-object-recognition task identical to that performed by Tang et al. [Nature 401 (1999) 63] and a novel-odor-recognition task analogously constructed. Although the results of the object recognition task were consistent with the previous literature, there was no evidence of an effect of NR2B over-expression on the retention of odor recognition memory in the specific task performed. As it was possible that, unlike object recognition memory, novel odor recognition is not NMDA-receptor-dependent, a second task was designed using the social transmission of food preference paradigm. In contrast to the foregoing olfactory task, there is evidence that the latter procedure is, indeed, NMDA-dependent. The results of the second study demonstrated that transgenic mice with NR2B over-expression had a clear memory advantage in this alternative odor memory paradigm. Taken together, these results suggest the NR2B subunit is an important component in some but not all forms of olfactory memory organization. Moreover, for those functions that are NMDA-receptor-dependent, these data support the growing literature demonstrating the importance of the NR2B subunit.

  19. Olfactory receptor neuron responses of a longhorned beetle, Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae), to pheromone, host, and non-host volatiles.

    Science.gov (United States)

    MacKay, Colin A; Sweeney, Jon D; Hillier, N Kirk

    2015-12-01

    Longhorn wood-boring beetles (Coleoptera: Cerambycidae) use olfactory cues to find mates and hosts for oviposition. Tetropium fuscum (Fabr.) is an invasive longhorned wood-boring beetle originating from Europe that has been established in Nova Scotia, Canada, since at least 1990. This study used single sensillum recordings (SSR) to determine the response of olfactory receptor neurons (ORNs) in the antennal sensilla of male and female T. fuscum to different kinds of olfactory cues, namely host volatiles, non-host volatiles, the aggregation pheromone of T. fuscum (fuscumol), and an aggregation pheromone emitted by other species of longhorn beetles (3-hydroxyhexan-2-one). Each compound had been previously shown to elicit antennal activity in T. fuscum using electroantennography or had been shown to elicit behavioral activity in T. fuscum or other cerambycids. There have been very few SSR studies done on cerambycids, and ours is the first to compare response profiles of pheromone components as well as host and non-host volatiles. Based on SSR studies with other insects, we predicted we would find ORNs that responded to the pheromone alone (pheromone-specialists), as well as ORNs that responded only to host or non-host volatiles, i.e., separation of olfactory cue perception at the ORN level. Also, because male T. fuscum emerge earlier than females and are the pheromone-emitting sex, we predicted that the number of pheromone-sensitive ORNs would be greater in females than males. We found 140 ORNs housed within 97 sensilla that responded to at least one of the 13 compounds. Fuscumol-specific ORNs made up 15% (21/140) of all recordings, but contrary to our prediction, an additional 22 ORNs (16%) responded to fuscumol plus at least one other compound; in total, fuscumol elicited a response from 43/140 (31%) of ORNs with fuscumol-specific ORNs accounting for half of these. Thus, our prediction that pheromone reception would be segregated on specialist ORNs was only partially

  20. Proteomic Analysis of the Human Olfactory Bulb.

    Science.gov (United States)

    Dammalli, Manjunath; Dey, Gourav; Madugundu, Anil K; Kumar, Manish; Rodrigues, Benvil; Gowda, Harsha; Siddaiah, Bychapur Gowrishankar; Mahadevan, Anita; Shankar, Susarla Krishna; Prasad, Thottethodi Subrahmanya Keshava

    2017-08-01

    The importance of olfaction to human health and disease is often underappreciated. Olfactory dysfunction has been reported in association with a host of common complex diseases, including neurological diseases such as Alzheimer's disease and Parkinson's disease. For health, olfaction or the sense of smell is also important for most mammals, for optimal engagement with their environment. Indeed, animals have developed sophisticated olfactory systems to detect and interpret the rich information presented to them to assist in day-to-day activities such as locating food sources, differentiating food from poisons, identifying mates, promoting reproduction, avoiding predators, and averting death. In this context, the olfactory bulb is a vital component of the olfactory system receiving sensory information from the axons of the olfactory receptor neurons located in the nasal cavity and the first place that processes the olfactory information. We report in this study original observations on the human olfactory bulb proteome in healthy subjects, using a high-resolution mass spectrometry-based proteomic approach. We identified 7750 nonredundant proteins from human olfactory bulbs. Bioinformatics analysis of these proteins showed their involvement in biological processes associated with signal transduction, metabolism, transport, and olfaction. These new observations provide a crucial baseline molecular profile of the human olfactory bulb proteome, and should assist the future discovery of biomarker proteins and novel diagnostics associated with diseases characterized by olfactory dysfunction.

  1. Expression of human olfactory receptor 10J5 in heart aorta, coronary artery, and endothelial cells and its functional role in angiogenesis.

    Science.gov (United States)

    Kim, Sung-Hee; Yoon, Yeo Cho; Lee, Ae Sin; Kang, NaNa; Koo, JaeHyung; Rhyu, Mee-Ra; Park, Jae-Ho

    2015-05-01

    ORs are ectopically expressed in non-chemosensory tissues including muscle, kidney, and keratinocytes; however, their physiological roles are largely unknown. We found that human olfactory receptor 10J5 (OR10J5) is expressed in the human aorta, coronary artery, and umbilical vein endothelial cells (HUVEC). Lyral induces Ca(2+) and phosphorylation of AKT in HUVEC. A knockdown study showed the inhibition of the lyral-induced Ca(2+) and the phosphorylation AKT and implied that these processes are mediated by OR10J5. In addition, lyral enhanced migration of HUVEC, which were also inhibited by RNAi in a migration assay. In addition, matrigel plug assay showed that lyral enhanced angiogenesis in vivo. Together these data demonstrate the physiological role of OR10J5 in angiogenesis and represent roles of ORs in HUVEC cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications.

    Science.gov (United States)

    Lagman, David; Ocampo Daza, Daniel; Widmark, Jenny; Abalo, Xesús M; Sundström, Görel; Larhammar, Dan

    2013-11-02

    Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the evolution of vision and the

  3. Olfactory neuroblastoma

    International Nuclear Information System (INIS)

    Rashid, D.; Ahmed, B.; Malik, S.M.; Khan, M.

    2000-01-01

    Olfactory neuroblastoma/esthesioneuroblastoma in a rare malignant tumour of the olfactory neuroepithelium. This is a report of 5 cases managed over the last 10 years at Combined Military Hospital, Rawalpindi. Age of the patients at presentation ranged from 27 to 70 years. The main symptoms were unilateral nasal obstruction and intermittent epistaxis. The mean duration of symptoms at presentation was 11 months. Two patients were staged as B and 3 as C at presentation. The stage of the disease correlated with the duration of symptoms. All the cases were diagnosed on histopathology. Three were offered combination of surgery and radiotherapy. One patient received only surgical treatment and one patient received radiotherapy and chemotherapy. Combination of surgery and radiotherapy showed best results. (author)

  4. Terminal-Nerve-Derived Neuropeptide Y Modulates Physiological Responses in the Olfactory Epithelium of Hungry Axolotls (Ambystoma mexicanum)

    Science.gov (United States)

    Mousley, Angela; Polese, Gianluca; Marks, Nikki J.; Eisthen, Heather L.

    2007-01-01

    The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by L-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances. PMID:16855098

  5. Terminal nerve-derived neuropeptide y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum).

    Science.gov (United States)

    Mousley, Angela; Polese, Gianluca; Marks, Nikki J; Eisthen, Heather L

    2006-07-19

    The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full-length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by l-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances.

  6. Single-nucleotide polymorphisms in the P2X7 receptor gene are associated with post-menopausal bone loss and vertebral fractures

    DEFF Research Database (Denmark)

    Rye Jørgensen, Niklas; Husted, Lise Bjerre; Skarratt, Kristen K

    2012-01-01

    to bone mass and fracture incidence in post-menopausal women. A total of 1694 women (aged 45-58) participating in the Danish Osteoporosis Prevention Study were genotyped for 12 functional P2X7 receptor variants. Bone mineral density was determined at baseline and after 10 years. In addition, vertebral...... had increased bone loss. In contrast, the Gln460Arg polymorphism was associated with protection against bone loss. The Ala348Thr polymorphism was associated with a lower vertebral fracture incidence 10 years after menopause. Finally, we developed a risk model, which integrated P2RX7 genotypes. Using...

  7. Mechanisms of permanent loss of olfactory receptor neurons induced by the herbicide 2,6-dichlorobenzonitrile: Effects on stem cells and noninvolvement of acute induction of the inflammatory cytokine IL-6

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Fang; Fang, Cheng [Laboratory of Molecular Toxicology, Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); School of Public Health, State University of New York at Albany, NY 12201 (United States); Schnittke, Nikolai [Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Schwob, James E. [Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Ding, Xinxin, E-mail: xding@wadsworth.org [Laboratory of Molecular Toxicology, Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); School of Public Health, State University of New York at Albany, NY 12201 (United States)

    2013-11-01

    We explored the mechanisms underlying the differential effects of two olfactory toxicants, the herbicide 2,6-dichlorobenzonitrile (DCBN) and the anti-thyroid drug methimazole (MMZ), on olfactory receptor neuron (ORN) regeneration in mouse olfactory epithelium (OE). DCBN, but not MMZ, induced inflammation-like pathological changes in OE, and DCBN increased interleukin IL-6 levels in nasal-wash fluid to much greater magnitude and duration than did MMZ. At 24 h after DCBN injection, the population of horizontal basal cells (HBCs; reserve, normally quiescent OE stem cells) lining the DMM became severely depleted as some of them detached from the basal lamina, and sloughed into the nasal cavity along with the globose basal cells (GBCs; heterogeneous population of stem and progenitor cells), neurons, and sustentacular cells of the neuroepithelium. In contrast, the layer of HBCs remained intact in MMZ-treated mice, as only the mature elements of the neuroepithelium were shed. Despite the respiratory metaplasia accompanying the greater severity of the DCBN lesion, residual HBCs that survived intoxication were activated by the injury and contributed to the metaplastic respiratory epithelium, as shown by tracing their descendants in a K5CreEr{sup T2}::fl(stop)TdTomato strain of mice in which recombination causes HBCs to express TdTomato in advance of the lesion. But, contrary to published observations with MMZ, the HBCs failed to form ORNs. A role for IL-6 in suppressing ORN regeneration in DCBN-treated mice was rejected by the failure of the anti-inflammatory drug dexamethasone to prevent the subsequent respiratory metaplasia in the DMM, suggesting that other factors lead to HBC neuro-incompetence. - Highlights: • The herbicide dichlobenil (DCBN) can damage olfactory epithelium stem cells. • Another olfactory toxicant, methimazole, leaves the olfactory stem cells intact. • DCBN, but not methimazole, induces a prolonged increase in nasal IL-6 levels. • Dexamethasone

  8. Olfactory Memory

    Science.gov (United States)

    Eichenbaum, Howard; Robitsek, R. Jonathan

    2009-01-01

    Odor-recognition memory in rodents may provide a valuable model of cognitive aging. In a recent study we used signal detection analyses to distinguish odor recognition based on recollection versus that based on familiarity. Aged rats were selectively impaired in recollection, with relative sparing of familiarity, and the deficits in recollection were correlated with spatial memory impairments. These results complement electro-physiological findings indicating age-associated deficits in the ability of hippocampal neurons to differentiate contextual information, and this information-processing impairment may underlie the common age-associated decline in olfactory and spatial memory. PMID:19686208

  9. Cross-adaptation between olfactory responses induced by two subgroups of odorant molecules.

    Science.gov (United States)

    Takeuchi, Hiroko; Imanaka, Yukie; Hirono, Junzo; Kurahashi, Takashi

    2003-09-01

    It has long been believed that vertebrate olfactory signal transduction is mediated by independent multiple pathways (using cAMP and InsP3 as second messengers). However, the dual presence of parallel pathways in the olfactory receptor cell is still controversial, mainly because of the lack of information regarding the single-cell response induced by odorants that have been shown to produce InsP3 exclusively (but not cAMP) in the olfactory cilia. In this study, we recorded activities of transduction channels of single olfactory receptor cells to InsP3-producing odorants. When the membrane potential was held at -54 mV, application of InsP3-producing odorants to the ciliary region caused an inward current. The reversal potential was 0 +/- 7 mV (mean +/- SD, n = 10). Actually, InsP3-producing odorants generated responses in a smaller fraction of cells (lilial, 3.4%; lyral, 1.7%) than the cAMP-producing odorant (cineole, 26%). But, fundamental properties of responses were surprisingly homologous; namely, spatial distribution of the sensitivity, waveforms, I-V relation, and reversal potential, dose dependence, time integration of stimulus period, adaptation, and recovery. By applying both types of odorants alternatively to the same cell, furthermore, we observed cells to exhibit symmetrical cross-adaptation. It seems likely that even with odorants with different modalities adaptation occurs completely depending on the amount of current flow. The data will also provide evidence showing that olfactory response generation and adaptation are regulated by a uniform mechanism for a wide variety of odorants.

  10. Stimulation of the sigma-1 receptor by DHEA enhances synaptic efficacy and neurogenesis in the hippocampal dentate gyrus of olfactory bulbectomized mice.

    Directory of Open Access Journals (Sweden)

    Shigeki Moriguchi

    Full Text Available Dehydroepiandrosterone (DHEA is the most abundant neurosteroid synthesized de novo in the central nervous system. We previously reported that stimulation of the sigma-1 receptor by DHEA improves cognitive function by activating calcium/calmodulin-dependent protein kinase II (CaMKII, protein kinase C and extracellular signal-regulated kinase in the hippocampus in olfactory bulbectomized (OBX mice. Here, we asked whether DHEA enhances neurogenesis in the subgranular zone of the hippocampal dentate gyrus (DG and improves depressive-like behaviors observed in OBX mice. Chronic treatment with DHEA at 30 or 60 mg/kg p.o. for 14 days significantly improved hippocampal LTP impaired in OBX mice concomitant with increased CaMKII autophosphorylation and GluR1 (Ser-831 phosphorylation in the DG. Chronic DHEA treatment also ameliorated depressive-like behaviors in OBX mice, as assessed by tail suspension and forced swim tests, while a single DHEA treatment had no affect. DHEA treatment also significantly increased the number of BrdU-positive neurons in the subgranular zone of the DG of OBX mice, an increase inhibited by treatment with NE-100, a sigma-1 receptor antagonist. DHEA treatment also significantly increased phosphorylation of Akt (Ser-473, Akt (Ser-308 and ERK in the DG. Furthermore, GSK-3β (Ser-9 phosphorylation increased in the DG of OBX mice possibly accounting for increased neurogenesis through Akt activation. Finally, we confirmed that DHEA treatment of OBX mice increases the number of BrdU-positive neurons co-expressing β-catenin, a downstream GSK-3βtarget. Overall, we conclude that sigma-1 receptor stimulation by DHEA ameliorates OBX-induced depressive-like behaviors by increasing neurogenesis in the DG through activation of the Akt/GSK-3β/β-catenin pathway.

  11. Assessment of Olfactory Memory in Olfactory Dysfunction.

    Science.gov (United States)

    Kollndorfer, Kathrin; Reichert, Johanna; Braunsteiner, Josephine; Schöpf, Veronika

    2017-01-01

    To assess all clinically relevant components of olfactory perception, examinations for olfactory sensitivity, discrimination, and identification are performed. Besides the standard perceptual test battery, episodic olfactory memory might offer additional information about olfactory abilities relative to these standard clinical tests. As both olfactory deficits and memory deficits are early symptoms in neurodegenerative disorders, olfactory memory may be of particular interest. However, to date little is known about episodic olfactory memory performance in patients with decreased olfactory function. This study includes the investigation of olfactory memory performance in 14 hyposmic patients (8 female, mean age 52.6 years) completing two episodic odor memory tests (Sniffin' Test of Odor Memory and Odor Memory Test). To control for a general impairment in memory function, a verbal and a figural memory test were carried out. A regression model with multiple predictors was calculated for both odor memory tests separately. Odor identification was identified as the only significant predictor for both odor memory tasks. From our results, we conclude that currently available olfactory memory tests are highly influenced by odor identification abilities, implying the need for the development and validation of additional tests in this field which could serve as additional olfactory perception variables for clinical assessment.

  12. A Critical Review of the Environmental Occurrence and Potential Effects in Aquatic Vertebrates of the Potent Androgen Receptor Agonist 17β-Trenbolone

    DEFF Research Database (Denmark)

    Ankley, Gerald T; Coady, Katherine K; Gross, Melanie

    2018-01-01

    to aquatic animals. In vitro studies indicate that, although βTRB can activate several nuclear hormone receptors, its highest affinity is for the AR in all vertebrate taxa examined, including fish. Short-term exposures of fish to ng/l water concentrations of βTRB can cause changes in endocrine function......-level effects of βTRB in sensitive species. This article is protected by copyright. All rights reserved....

  13. The evolutionary history of vertebrate cranial placodes II. Evolution of ectodermal patterning.

    Science.gov (United States)

    Schlosser, Gerhard; Patthey, Cedric; Shimeld, Sebastian M

    2014-05-01

    Cranial placodes are evolutionary innovations of vertebrates. However, they most likely evolved by redeployment, rewiring and diversification of preexisting cell types and patterning mechanisms. In the second part of this review we compare vertebrates with other animal groups to elucidate the evolutionary history of ectodermal patterning. We show that several transcription factors have ancient bilaterian roles in dorsoventral and anteroposterior regionalisation of the ectoderm. Evidence from amphioxus suggests that ancestral chordates then concentrated neurosecretory cells in the anteriormost non-neural ectoderm. This anterior proto-placodal domain subsequently gave rise to the oral siphon primordia in tunicates (with neurosecretory cells being lost) and anterior (adenohypophyseal, olfactory, and lens) placodes of vertebrates. Likewise, tunicate atrial siphon primordia and posterior (otic, lateral line, and epibranchial) placodes of vertebrates probably evolved from a posterior proto-placodal region in the tunicate-vertebrate ancestor. Since both siphon primordia in tunicates give rise to sparse populations of sensory cells, both proto-placodal domains probably also gave rise to some sensory receptors in the tunicate-vertebrate ancestor. However, proper cranial placodes, which give rise to high density arrays of specialised sensory receptors and neurons, evolved from these domains only in the vertebrate lineage. We propose that this may have involved rewiring of the regulatory network upstream and downstream of Six1/2 and Six4/5 transcription factors and their Eya family cofactors. These proteins, which play ancient roles in neuronal differentiation were first recruited to the dorsal non-neural ectoderm in the tunicate-vertebrate ancestor but subsequently probably acquired new target genes in the vertebrate lineage, allowing them to adopt new functions in regulating proliferation and patterning of neuronal progenitors. Copyright © 2014 Elsevier Inc. All rights

  14. Organization and distribution of glomeruli in the bowhead whale olfactory bulb

    Directory of Open Access Journals (Sweden)

    Takushi Kishida

    2015-04-01

    Full Text Available Although modern baleen whales (Mysticeti retain a functional olfactory system that includes olfactory bulbs, cranial nerve I and olfactory receptor genes, their olfactory capabilities have been reduced to a great degree. This reduction likely occurred as a selective response to their fully aquatic lifestyle. The glomeruli that occur in the olfactory bulb can be divided into two non-overlapping domains, a dorsal domain and a ventral domain. Recent molecular studies revealed that all modern whales have lost olfactory receptor genes and marker genes that are specific to the dorsal domain. Here we show that olfactory bulbs of bowhead whales (Balaena mysticetus lack glomeruli on the dorsal side, consistent with the molecular data. In addition, we estimate that there are more than 4,000 glomeruli elsewhere in the bowhead whale olfactory bulb, which is surprising given that bowhead whales possess only 80 intact olfactory receptor genes. Olfactory sensory neurons that express the same olfactory receptors in rodents generally project to two specific glomeruli in an olfactory bulb, implying an approximate 1:2 ratio of the number of olfactory receptors to the number of glomeruli. Here we show that this ratio does not apply to bowhead whales, reiterating the conceptual limits of using rodents as model organisms for understanding the initial coding of odor information among mammals.

  15. Metabolic stabilization of acetylcholine receptors in vertebrate neuromuscular junction by muscle activity

    International Nuclear Information System (INIS)

    Rotzler, S.; Brenner, H.R.

    1990-01-01

    The effects of muscle activity on the growth of synaptic acetylcholine receptor (AChR) accumulations and on the metabolic AChR stability were investigated in rat skeletal muscle. Ectopic end plates induced surgically in adult soleus muscle were denervated early during development when junctional AChR number and stability were still low and, subsequently, muscles were either left inactive or they were kept active by chronic exogenous stimulation. AChR numbers per ectopic AChR cluster and AChR stabilities were estimated from the radioactivity and its decay with time, respectively, of end plate sites whose AChRs had been labeled with 125 I-alpha-bungarotoxin (alpha-butx). The results show that the metabolic stability of the AChRs in ectopic clusters is reversibly increased by muscle activity even when innervation is eliminated very early in development. 1 d of stimulation is sufficient to stabilize the AChRs in ectopic AChR clusters. Muscle stimulation also produced an increase in the number of AChRs at early denervated end plates. Activity-induced cluster growth occurs mainly by an increase in area rather than in AChR density, and for at least 10 d after denervation is comparable to that in normally developing ectopic end plates. The possible involvement of AChR stabilization in end plate growth is discussed

  16. Effects of repeated 9 and 30-day exposure to extremely low-frequency electromagnetic fields on social recognition behavior and estrogen receptors expression in olfactory bulb of Wistar female rats.

    Science.gov (United States)

    Bernal-Mondragón, C; Arriaga-Avila, V; Martínez-Abundis, E; Barrera-Mera, B; Mercado-Gómez, O; Guevara-Guzmán, R

    2017-02-01

    We investigated the short- and long-term effects of extremely low-frequency electromagnetic fields (EMF) on social recognition behavior and expression of α- and β-estrogen receptors (ER). Rats were exposed to 60-Hz electromagnetic fields for 9 or 30 days and tested for social recognition behavior. Immunohistochemistry and western blot assays were performed to evaluate α- and β-ER expression in the olfactory bulb of intact, ovariectomized (OVX), and ovariectomized+estradiol (E2) replacement (OVX+E2). Ovariectomization showed impairment of social recognition after 9 days of EMF exposure and a complete recovery after E2 replacement and so did those after 30 days. Short EMF exposure increased expression of β-ER in intact, but not in the others. Longer exposure produced a decrease in intact but an increase in OVX and OVX+E2. Our findings suggest a significant role for β-estrogen receptors and a lack of effect for α-estrogen receptors on a social recognition task. EMF: extremely low frequency electromagnetic fields; ERs: estrogen receptors; OB: olfactory bulb; OVX: ovariectomized; OVX + E 2 : ovariectomized + estradiol replacement; IEI: interexposure interval; β-ER: beta estrogen receptor; E 2 : replacement of estradiol; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; WB: Western blot; PBS: phosphate-buffer saline; PB: phosphate-buffer.

  17. Differential response of olfactory sensory neuron populations to copper ion exposure in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Lazzari, Maurizio, E-mail: maurizio.lazzari@unibo.it; Bettini, Simone; Milani, Liliana; Maurizii, Maria Gabriella; Franceschini, Valeria

    2017-02-15

    Highlights: • Copper exposure affects ciliated olfactory receptors more than microvillar cells. • Crypt olfactory sensory neurons are not affected by copper exposure. • Copper exposure induces an increase in the amount of sensory epithelium. - Abstract: The peripheral olfactory system of fish is in direct contact with the external aqueous environment, so dissolved contaminants can easily impair sensory functions and cause neurobehavioral injuries. The olfactory epithelium of fish is arranged in lamellae forming a rosette in the olfactory cavity and contains three main types of olfactory sensory neurons (OSNs): ciliated (cOSNs) and microvillous olfactory sensory neurons (mOSNs), common to all vertebrates, and a third minor group of olfactory neurons, crypt cells, absent in tetrapods. Since copper is a ubiquitously diffusing olfactory toxicant and a spreading contaminant in urban runoff, we investigated the effect of low copper concentration on the three different OSNs in the olfactory epithelium of zebrafish, a model system widely used in biological research. Image analysis was applied for morphometry and quantification of immunohistochemically detected OSNs. Copper exposure resulted in an evident decrease in olfactory epithelium thickness. Moreover, after exposure, the lamellae of the dorsal and ventral halves of the olfactory rosettes showed a different increase in their sensory areas, suggesting a lateral migration of new cells into non-sensory regions. The results of the present study provide clear evidence of a differential response of the three neural cell populations of zebrafish olfactory mucosa after 96 h of exposure to copper ions at the sublethal concentration of 30 μg L{sup −1}. Densitometric values of cONS, immunostained with anti-G {sub αolf}, decreased of about 60% compared to the control. When the fish were transferred to water without copper addition and examined after 3, 10 and 30 days, we observed a partial restoration of anti-G {sub

  18. Differential response of olfactory sensory neuron populations to copper ion exposure in zebrafish

    International Nuclear Information System (INIS)

    Lazzari, Maurizio; Bettini, Simone; Milani, Liliana; Maurizii, Maria Gabriella; Franceschini, Valeria

    2017-01-01

    Highlights: • Copper exposure affects ciliated olfactory receptors more than microvillar cells. • Crypt olfactory sensory neurons are not affected by copper exposure. • Copper exposure induces an increase in the amount of sensory epithelium. - Abstract: The peripheral olfactory system of fish is in direct contact with the external aqueous environment, so dissolved contaminants can easily impair sensory functions and cause neurobehavioral injuries. The olfactory epithelium of fish is arranged in lamellae forming a rosette in the olfactory cavity and contains three main types of olfactory sensory neurons (OSNs): ciliated (cOSNs) and microvillous olfactory sensory neurons (mOSNs), common to all vertebrates, and a third minor group of olfactory neurons, crypt cells, absent in tetrapods. Since copper is a ubiquitously diffusing olfactory toxicant and a spreading contaminant in urban runoff, we investigated the effect of low copper concentration on the three different OSNs in the olfactory epithelium of zebrafish, a model system widely used in biological research. Image analysis was applied for morphometry and quantification of immunohistochemically detected OSNs. Copper exposure resulted in an evident decrease in olfactory epithelium thickness. Moreover, after exposure, the lamellae of the dorsal and ventral halves of the olfactory rosettes showed a different increase in their sensory areas, suggesting a lateral migration of new cells into non-sensory regions. The results of the present study provide clear evidence of a differential response of the three neural cell populations of zebrafish olfactory mucosa after 96 h of exposure to copper ions at the sublethal concentration of 30 μg L"−"1. Densitometric values of cONS, immunostained with anti-G _α_o_l_f, decreased of about 60% compared to the control. When the fish were transferred to water without copper addition and examined after 3, 10 and 30 days, we observed a partial restoration of anti-G _

  19. Cladistic analysis of olfactory and vomeronasal systems.

    Science.gov (United States)

    Ubeda-Bañon, Isabel; Pro-Sistiaga, Palma; Mohedano-Moriano, Alicia; Saiz-Sanchez, Daniel; de la Rosa-Prieto, Carlos; Gutierrez-Castellanos, Nicolás; Lanuza, Enrique; Martinez-Garcia, Fernando; Martinez-Marcos, Alino

    2011-01-01

    Most tetrapods possess two nasal organs for detecting chemicals in their environment, which are the sensory detectors of the olfactory and vomeronasal systems. The seventies' view that the olfactory system was only devoted to sense volatiles, whereas the vomeronasal system was exclusively specialized for pheromone detection was challenged by accumulating data showing deep anatomical and functional interrelationships between both systems. In addition, the assumption that the vomeronasal system appeared as an adaptation to terrestrial life is being questioned as well. The aim of the present work is to use a comparative strategy to gain insight in our understanding of the evolution of chemical "cortex." We have analyzed the organization of the olfactory and vomeronasal cortices of reptiles, marsupials, and placental mammals and we have compared our findings with data from other taxa in order to better understand the evolutionary history of the nasal sensory systems in vertebrates. The olfactory and vomeronsasal cortices have been re-investigated in garter snakes (Thamnophis sirtalis), short-tailed opossums (Monodelphis domestica), and rats (Rattus norvegicus) by tracing the efferents of the main and accessory olfactory bulbs using injections of neuroanatomical anterograde tracers (dextran-amines). In snakes, the medial olfactory tract is quite evident, whereas the main vomeronasal-recipient structure, the nucleus sphaericus is a folded cortical-like structure, located at the caudal edge of the amygdala. In marsupials, which are acallosal mammals, the rhinal fissure is relatively dorsal and the olfactory and vomeronasal cortices relatively expanded. Placental mammals, like marsupials, show partially overlapping olfactory and vomeronasal projections in the rostral basal telencephalon. These data raise the interesting question of how the telencephalon has been re-organized in different groups according to the biological relevance of chemical senses.

  20. Early Olfactory Processing in Drosophila: Mechanisms and Principles

    OpenAIRE

    Wilson, Rachel I.

    2013-01-01

    In the olfactory system of Drosophila melanogaster, it is relatively straightforward to make in vivo measurements of activity in neurons corresponding to targeted processing. This, together with the numerical simplicity of the Drosophila olfactory system, has produced rapid gains in our understanding of Drosophila olfaction. This review summarizes the neurophysiology of the first two layers of this system: the peripheral olfactory receptor neurons and their postsynaptic targets in the antenna...

  1. Co-regulation of a large and rapidly evolving repertoire of odorant receptor genes

    Directory of Open Access Journals (Sweden)

    Lane Robert P

    2007-09-01

    Full Text Available Abstract The olfactory system meets niche- and species-specific demands by an accelerated evolution of its odorant receptor repertoires. In this review, we describe evolutionary processes that have shaped olfactory and vomeronasal receptor gene families in vertebrate genomes. We emphasize three important periods in the evolution of the olfactory system evident by comparative genomics: the adaptation to land in amphibian ancestors, the decline of olfaction in primates, and the delineation of putative pheromone receptors concurrent with rodent speciation. The rapid evolution of odorant receptor genes, the sheer size of the repertoire, as well as their wide distribution in the genome, presents a developmental challenge: how are these ever-changing odorant receptor repertoires coordinated within the olfactory system? A central organizing principle in olfaction is the specialization of sensory neurons resulting from each sensory neuron expressing only ~one odorant receptor allele. In this review, we also discuss this mutually exclusive expression of odorant receptor genes. We have considered several models to account for co-regulation of odorant receptor repertoires, as well as discussed a new hypothesis that invokes important epigenetic properties of the system.

  2. Olfactory Neuroblastoma: Diagnostic Difficulty

    Directory of Open Access Journals (Sweden)

    Vidya MN,

    2011-01-01

    Full Text Available Olfactory neuroblastoma is an uncommon malignant tumor of sinonasal tract arising from the olfactory neuro epithelium. The olfactory neuroblastomas presenting with divergent histomorphologies like, epithelial appearance of cells, lacking a neuro fibrillary background and absence of rosettes are difficult to diagnose. Such cases require immunohistochemistry to establish the diagnosis. We describe the clinical features, pathological and immunohistochemical findings of grade IV Olfactory neuroblastoma in a 57 year old man

  3. Chronic Blockade of Brain Endothelin Receptor Type-A (ETA Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Luis R. Cassinotti

    2018-02-01

    Full Text Available Overactivity of the sympathetic nervous system and central endothelins (ETs are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA-salt hypertensive rats. Following brain ET receptor type A (ETA blockade by BQ610 (selective antagonist, transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ETA blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein in the right OB of hypertensive animals. However, ETA blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ETA are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

  4. Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats.

    Science.gov (United States)

    Cassinotti, Luis R; Guil, María J; Schöller, Mercedes I; Navarro, Mónica P; Bianciotti, Liliana G; Vatta, Marcelo S

    2018-02-27

    Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ET A ) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ET A blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ET A blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ET A are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

  5. Accumulation of [35S]taurine in peripheral layers of the olfactory bulb

    International Nuclear Information System (INIS)

    Quinn, M.R.; Wysocki, C.J.; Sturman, J.A.; Wen, G.Y.

    1981-01-01

    Accumulation of [ 35 S]taurine in the laminae of the olfactory bulb of the adult cat, rat, mouse and rabbit was examined autoradiographically. [ 35 S]Taurine was administered either i.p. or i.v. and olfactory bulbs were excised 24 h post-injection. High concentrations of [ 35 S]taurine were restricted to the olfactory nerve and glomerular layers of the olfactory bulb in all species examined. Olfactory neurons are continuously renewed and the results obtained suggest that taurine may have an important role in olfactory receptor axons. (Auth.)

  6. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.

  7. Phylogenic aspects of the amphibian dual olfactory system.

    Science.gov (United States)

    Taniguchi, Kazumi; Saito, Shouichiro; Oikawa, Toshihiro; Taniguchi, Kazuyuki

    2008-01-01

    The phylogenic significance of the subdivision of dual olfactory system is reviewed mainly on the basis of our findings by electron microscopy and lectin histochemistry in the three amphibian species. The dual olfactory system is present in common in these species and consists of the projection from the olfactory epithelium (OE) to the main olfactory bulb (MOB) and that from the vomeronasal epithelium (VNE) to the accessory olfactory bulb (AOB). The phylogenic significance of subdivisions in the dual olfactory system in the amphibian must differently be interpreted. The subdivision of the MOB into its dorsal region (D-MOB) and ventral region (V-MOB) in Xenopus laevis must be attributed to the primitive features in their olfactory receptors. The middle cavity epithelium lining the middle cavity of this frog possesses both ciliated sensory cells and microvillous sensory cells, reminding the OE in fish. The subdivision of the AOB into the rostral (R-AOB) and caudal part (C-AOB) in Bufo japonicus formosus must be regarded as an advanced characteristic. The lack of subdivisions in both MOB and AOB in Cynops pyrrhogaster may reflect their phylogenic primitiveness. Since our lectin histochemistry to detect glycoconjugates expressed in the olfactory pathway reveals the subdivisions in the dual olfactory system in the amphibian, the glycoconjugates may deeply participate in the organization and function of olfactory pathways in phylogeny.

  8. Inhibition of Inflammation-Associated Olfactory Loss by Etanercept in an Inducible Olfactory Inflammation Mouse Model.

    Science.gov (United States)

    Jung, Yong Gi; Lane, Andrew P

    2016-06-01

    To determine the effect of a soluble human tumor necrosis factor alpha (TNF-α) receptor blocker (etanercept) on an inducible olfactory inflammation (IOI) mouse model. An in vivo study using a transgenic mouse model. Research laboratory. To study the impact of chronic inflammation on the olfactory system, a transgenic mouse model of chronic rhinosinusitis-associated olfactory loss was utilized (IOI mouse), expressing TNF-α in a temporally controlled fashion within the olfactory epithelium. In one group of mice (n = 4), etanercept was injected intraperitoneally (100 μg/dose, 3 times/week) concurrent with a 2-week period of TNF-α expression. A second group of mice (n = 2) underwent induction of TNF-α expression for 8 weeks, with etanercept treatment administered during the final 2 weeks of inflammation. Olfactory function was assayed by elecro-olfactogram (EOG), and olfactory tissue was processed for histology and immunohistochemical staining. Each group was compared with an equal-number control group. Compared with nontreated IOI mice, etanercept-treated IOI mice showed significantly improved EOG responses after 2 weeks (P loss of olfactory epithelium and no EOG response in nontreated IOI mice. However, in etanercept-treated mice, regeneration of olfactory epithelium was observed. Concomitant administration of etanercept in IOI mice results in interruption of TNF-α-induced olfactory loss and induction of neuroepithelial regeneration. This demonstrates that etanercept has potential utility as a tool for elucidating the role of TNF-α in other olfactory inflammation models. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  9. Female mice lacking cholecystokinin 1 receptors have compromised neurogenesis, and fewer dopaminergic cells in the olfactory bulb

    Directory of Open Access Journals (Sweden)

    Yi eSui

    2013-03-01

    Full Text Available Neurogenesis in the adult rodent brain is largely restricted to the subependymal zone (SVZ of the lateral ventricle and subgranular zone (SGZ of the dentate gyrus (DG. We examined whether cholecystokinin (CCK through actions mediated by CCK1 receptors (CCK1R is involved in regulating neurogenesis. Proliferating cells in the SVZ, measured by 5-bromo-2-deoxyuridine (BrdU injected 2 hours prior to death or by immunoreactivity against Ki67, were reduced by 37% and 42%, respectively, in female (but not male mice lacking CCK1Rs (CCK1R-/- compared to wild-type (WT. Generation of neuroblasts in the SVZ and rostral migratory stream was also affected, since the number of doublecortin (DCX-immunoreactive (ir neuroblasts in these regions decreased by 29%. In the SGZ of female CCK1R-/- mice, BrdU-positive (+ and Ki67-ir cells were reduced by 38% and 56%, respectively, while DCX-ir neuroblasts were down 80%. Subsequently, the effect of reduced SVZ/SGZ proliferation on the generation and survival of mature adult-born cells in female CCK1R-/- mice was examined. In the OB granule cell layer (GCL, the number of neuronal nuclei (NeuN-ir and calretinin-ir cells was stable compared to WT, and 42 days after BrdU injections, the number of BrdU+ cells co-expressing GABA- or NeuN-like immunoreactivity (LI was similar. Compared to WT, the granule cell layer of the DG in female CCK1R-/- mice had a similar number of calbindin-ir cells and BrdU+ cells co-expressing calbindin-LI 42 days after BrdU injections. However, the OB glomerular layer (GL of CCK1R-/- female mice had 11% fewer NeuN-ir cells, 23% less TH-ir cells, and a 38% and 29% reduction in BrdU+ cells that co-expressed TH-LI or GABA-LI, respectively. We conclude that CCK, via CCK1Rs, is involved in regulating the generation of proliferating cells and neuroblasts in the adult female mouse brain, and mechanisms are in place to maintain steady neuronal populations in the OB and DG when the rate of proliferation is

  10. Identification of the western tarnished plant bug (lygus hesperus) olfactory co-receptor orco: expression profile and confirmation of atypical membrane topology

    Science.gov (United States)

    Lygus hesperus (western tarnished plant bug) is an agronomically important pest species of numerous cropping systems. Similar to other insects, a critical component underlying behaviors is the perception and discrimination of olfactory cues. Consequently, the molecular basis of olfaction in this spe...

  11. Inhibitory neurotransmission and olfactory memory in honeybees.

    Science.gov (United States)

    El Hassani, Abdessalam Kacimi; Giurfa, Martin; Gauthier, Monique; Armengaud, Catherine

    2008-11-01

    In insects, gamma-aminobutyric acid (GABA) and glutamate mediate fast inhibitory neurotransmission through ligand-gated chloride channel receptors. Both GABA and glutamate have been identified in the olfactory circuit of the honeybee. Here we investigated the role of inhibitory transmission mediated by GABA and glutamate-gated chloride channels (GluCls) in olfactory learning and memory in honeybees. We combined olfactory conditioning with injection of ivermectin, an agonist of GluCl receptors. We also injected a blocker of glutamate transporters (L-trans-PDC) or a GABA analog (TACA). We measured acquisition and retention 1, 24 and 48 h after the last acquisition trial. A low dose of ivermectin (0.01 ng/bee) impaired long-term olfactory memory (48 h) while a higher dose (0.05 ng/bee) had no effect. Double injections of ivermectin and L-trans-PDC or TACA had different effects on memory retention, depending on the doses and agents combined. When the low dose of ivermectin was injected after Ringer, long-term memory was again impaired (48 h). Such an effect was rescued by injection of both TACA and L-trans-PDC. A combination of the higher dose of ivermectin and TACA decreased retention at 48 h. We interpret these results as reflecting the involvement of both GluCl and GABA receptors in the impairment of olfactory long-term memory induced by ivermectin. These results illustrate the diversity of inhibitory transmission and its implication in long-term olfactory memory in honeybees.

  12. Morphology of the olfactory system in the predatory mite Phytoseiulus persimilis.

    Science.gov (United States)

    van Wijk, Michiel; Wadman, Wytse J; Sabelis, Maurice W

    2006-01-01

    The predatory mite Phytoseiulus persimilis locates its prey, the two-spotted spider mite, by means of herbivore-induced plant volatiles. The olfactory response to this quantitatively and qualitatively variable source of information is particularly well documented. The mites perform this task with a peripheral olfactory system that consists of just five putative olfactory sensilla that reside in a dorsal field at the tip of their first pair of legs. The receptor cells innervate a glomerular olfactory lobe just ventral of the first pedal ganglion. We have made a 3D reconstruction of the caudal half of the olfactory lobe in adult females. The glomerular organization as well as the glomerular innervation appears conserved across different individuals. The adult females have, by approximation, a 1:1 ratio of olfactory receptor cells to olfactory glomeruli.

  13. Intrinsic and Extrinsic Neuromodulation of Olfactory Processing.

    Science.gov (United States)

    Lizbinski, Kristyn M; Dacks, Andrew M

    2017-01-01

    Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a "memory" by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform.

  14. Odor preference learning and memory modify GluA1 phosphorylation and GluA1 distribution in the neonate rat olfactory bulb: testing the AMPA receptor hypothesis in an appetitive learning model.

    Science.gov (United States)

    Cui, Wen; Darby-King, Andrea; Grimes, Matthew T; Howland, John G; Wang, Yu Tian; McLean, John H; Harley, Carolyn W

    2011-01-01

    An increase in synaptic AMPA receptors is hypothesized to mediate learning and memory. AMPA receptor increases have been reported in aversive learning models, although it is not clear if they are seen with memory maintenance. Here we examine AMPA receptor changes in a cAMP/PKA/CREB-dependent appetitive learning model: odor preference learning in the neonate rat. Rat pups were given a single pairing of peppermint and 2 mg/kg isoproterenol, which produces a 24-h, but not a 48-h, peppermint preference in the 7-d-old rat pup. GluA1 PKA-dependent phosphorylation peaked 10 min after the 10-min training trial and returned to baseline within 90 min. At 24 h, GluA1 subunits did not change overall but were significantly increased in synaptoneurosomes, consistent with increased membrane insertion. Immunohistochemistry revealed a significant increase in GluA1 subunits in olfactory bulb glomeruli, the targets of olfactory nerve axons. Glomerular increases were seen at 3 and 24 h after odor exposure in trained pups, but not in control pups. GluA1 increases were not seen as early as 10 min after training and were no longer observed 48 h after training when odor preference is no longer expressed behaviorally. Thus, the pattern of increased GluA1 membrane expression closely follows the memory timeline. Further, blocking GluA1 insertion using an interference peptide derived from the carboxyl tail of the GluA1 subunit inhibited 24 h odor preference memory providing causative support for our hypothesis. PKA-mediated GluA1 phosphorylation and later GluA1 insertion could, conjointly, provide increased AMPA function to support both short-term and long-term appetitive memory.

  15. Focal and temporal release of glutamate in the mushroom bodies improves olfactory memory in Apis mellifera.

    Science.gov (United States)

    Locatelli, Fernando; Bundrock, Gesine; Müller, Uli

    2005-12-14

    In contrast to vertebrates, the role of the neurotransmitter glutamate in learning and memory in insects has hardly been investigated. The reason is that a pharmacological characterization of insect glutamate receptors is still missing; furthermore, it is difficult to locally restrict pharmacological interventions. In this study, we overcome these problems by using locally and temporally defined photo-uncaging of glutamate to study its role in olfactory learning and memory formation in the honeybee, Apis mellifera. Uncaging glutamate in the mushroom bodies immediately after a weak training protocol induced a higher memory rate 2 d after training, mimicking the effect of a strong training protocol. Glutamate release before training does not facilitate memory formation, suggesting that glutamate mediates processes triggered by training and required for memory formation. Uncaging glutamate in the antennal lobes shows no effect on memory formation. These results provide the first direct evidence for a temporally and locally restricted function of glutamate in memory formation in honeybees and insects.

  16. GEI-8, a homologue of vertebrate nuclear receptor corepressor NCoR/SMRT, regulates gonad development and neuronal functions in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Pavol Mikoláš

    Full Text Available NCoR and SMRT are two paralogous vertebrate proteins that function as corepressors with unliganded nuclear receptors. Although C. elegans has a large number of nuclear receptors, orthologues of the corepressors NCoR and SMRT have not unambiguously been identified in Drosophila or C. elegans. Here, we identify GEI-8 as the closest homologue of NCoR and SMRT in C. elegans and demonstrate that GEI-8 is expressed as at least two isoforms throughout development in multiple tissues, including neurons, muscle and intestinal cells. We demonstrate that a homozygous deletion within the gei-8 coding region, which is predicted to encode a truncated protein lacking the predicted NR domain, results in severe mutant phenotypes with developmental defects, slow movement and growth, arrested gonadogenesis and defects in cholinergic neurotransmission. Whole genome expression analysis by microarrays identified sets of de-regulated genes consistent with both the observed mutant phenotypes and a role of GEI-8 in regulating transcription. Interestingly, the upregulated transcripts included a predicted mitochondrial sulfide:quinine reductase encoded by Y9C9A.16. This locus also contains non-coding, 21-U RNAs of the piRNA class. Inhibition of the expression of the region coding for 21-U RNAs leads to irregular gonadogenesis in the homozygous gei-8 mutants, but not in an otherwise wild-type background, suggesting that GEI-8 may function in concert with the 21-U RNAs to regulate gonadogenesis. Our results confirm that GEI-8 is the orthologue of the vertebrate NCoR/SMRT corepressors and demonstrate important roles for this putative transcriptional corepressor in development and neuronal function.

  17. Caffeine and the olfactory bulb.

    Science.gov (United States)

    Hadfield, M G

    1997-08-01

    Caffeine, a popular CNS stimulant, is the most widely used neuroactive drug. Present in coffee, tea, chocolate, and soft drinks as well as over-the-counter and prescription medications, it influences millions of users. This agent has achieved recent notoriety because its dependency consequences and addictive potential have been re-examined and emphasized. Caffeine's central actions are thought to be mediated through adenosine (A) receptors and monoamine neurotransmitters. The present article suggests that the olfactory bulb (OB) may be an important site in the brain that is responsible for caffeine's central actions in several species. This conclusion is based on the extraordinarily robust and selective effects of caffeine on norepinephrine (NE), dopamine (DA), and particularly serotonin (5HT) utilization in the OB of mice. We believe that these phenomena should be given appropriate consideration as a basis for caffeine's central actions, even in primates. Concurrently, we review a rich rodent literature concerned with A, 5HT, NE, and DA receptors in the OB and related structures along with other monoamine parameters. We also review a more limited literature concerned with the primate OB. Finally, we cite the literature that treats the dependency and addictive effects of caffeine in humans, and relate the findings to possible olfactory mechanisms.

  18. CD36 is involved in oleic acid detection by the murine olfactory system.

    Directory of Open Access Journals (Sweden)

    Sonja eOberland

    2015-09-01

    Full Text Available Olfactory signals influence food intake in a variety of species. To maximize the chances of finding a source of calories, an animal’s preference for fatty foods and triglycerides already becomes apparent during olfactory food search behavior. However, the molecular identity of both receptors and ligands mediating olfactory-dependent fatty acid recognition are, so far, undescribed. We here describe that a subset of olfactory sensory neurons expresses the fatty acid receptor CD36 and demonstrate a receptor-like localization of CD36 in olfactory cilia by STED microscopy. CD36-positive olfactory neurons share olfaction-specific transduction elements and project to numerous glomeruli in the ventral olfactory bulb. In accordance with the described roles of CD36 as fatty acid receptor or co-receptor in other sensory systems, the number of olfactory neurons responding to oleic acid, a major milk component, in Ca2+ imaging experiments is drastically reduced in young CD36 knock-out mice. Strikingly, we also observe marked age-dependent changes in CD36 localization, which is prominently present in the ciliary compartment only during the suckling period. Our results support the involvement of CD36 in fatty acid detection by the mammalian olfactory system.

  19. Comparative genomic analysis reveals independent expansion of a lineage-specific gene family in vertebrates: The class II cytokine receptors and their ligands in mammals and fish

    Directory of Open Access Journals (Sweden)

    Mogensen Knud

    2003-07-01

    Full Text Available Abstract Background The high degree of sequence conservation between coding regions in fish and mammals can be exploited to identify genes in mammalian genomes by comparison with the sequence of similar genes in fish. Conversely, experimentally characterized mammalian genes may be used to annotate fish genomes. However, gene families that escape this principle include the rapidly diverging cytokines that regulate the immune system, and their receptors. A classic example is the class II helical cytokines (HCII including type I, type II and lambda interferons, IL10 related cytokines (IL10, IL19, IL20, IL22, IL24 and IL26 and their receptors (HCRII. Despite the report of a near complete pufferfish (Takifugu rubripes genome sequence, these genes remain undescribed in fish. Results We have used an original strategy based both on conserved amino acid sequence and gene structure to identify HCII and HCRII in the genome of another pufferfish, Tetraodon nigroviridis that is amenable to laboratory experiments. The 15 genes that were identified are highly divergent and include a single interferon molecule, three IL10 related cytokines and their potential receptors together with two Tissue Factor (TF. Some of these genes form tandem clusters on the Tetraodon genome. Their expression pattern was determined in different tissues. Most importantly, Tetraodon interferon was identified and we show that the recombinant protein can induce antiviral MX gene expression in Tetraodon primary kidney cells. Similar results were obtained in Zebrafish which has 7 MX genes. Conclusion We propose a scheme for the evolution of HCII and their receptors during the radiation of bony vertebrates and suggest that the diversification that played an important role in the fine-tuning of the ancestral mechanism for host defense against infections probably followed different pathways in amniotes and fish.

  20. Molecular Cloning, Genomic Organization and Developmental Regulation of a Novel Receptor from Drosophila melanogaster Structurally Related to Gonadotropin-Releasing Hormone Receptors from Vertebrates

    DEFF Research Database (Denmark)

    Hauser, Frank; Søndergaard, Leif; Grimmelikhuijzen, Cornelis J.P.

    1998-01-01

    After screening the data base of the BerkeleyDrosophilaGenome Project with a sequence coding for the transmembrane region of a G protein-coupled receptor, we found thatDrosophilamight contain a gene coding for a receptor that is structurally related to the Gonadotropin-Releasing Hormone (GnRH) re...

  1. Expression of olfactory signaling genes in the eye.

    Directory of Open Access Journals (Sweden)

    Alexey Pronin

    Full Text Available To advance our understanding how the outer eye interacts with its environment, we asked which cellular receptors are expressed in the cornea, focusing on G protein-coupled receptors.Total RNA from the mouse cornea was subjected to next-generation sequencing using the Illumina platform. The data was analyzed with TopHat and CuffLinks software packages. Expression of a representative group of genes detected by RNA-seq was further analyzed by RT-PCR and in situ hybridization using RNAscope technology and fluorescent microscopy.We generated more than 46 million pair-end reads from mouse corneal RNA. Bioinformatics analysis revealed that the mouse corneal transcriptome reconstructed from these reads represents over 10,000 gene transcripts. We identified 194 GPCR transcripts, of which 96 were putative olfactory receptors. RT-PCR analysis confirmed the presence of several olfactory receptors and related genes, including olfactory marker protein and the G protein associated with olfaction, Gαolf. In situ hybridization showed that mRNA for olfactory marker protein, Gαolf and possibly some olfactory receptors were found in the corneal epithelial cells. In addition to the corneal epithelium, Gαolf was present in the ganglionic and inner nuclear layers of the retina. One of the olfactory receptors, Olfr558, was present primarily in vessels of the eye co-stained with antibodies against alpha-smooth muscle actin, indicating expression in arterioles.Several species of mRNA encoding putative olfactory receptors and related genes are expressed in the mouse cornea and other parts of the eye indicating they may play a role in sensing chemicals in the ocular environment.

  2. Effects of cadmium on olfactory mediated behaviors and molecular biomarkers in coho salmon (Oncorhynchus kisutch)

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Chase R.; Gallagher, Evan P., E-mail: evang3@u.washington.edu

    2013-09-15

    Highlights: •Low Cd exposures elicited significant olfactory mediated behavioral changes independent of histological injury. •The olfactory behavioral deficits persisted following a 16-day depuration. •Olfactory molecular biomarkers expression was strongly linked to injury to the olfactory epithelium. •Cd induced a strong antioxidant response in the coho salmon olfactory system. •Results suggest a sensitivity of salmonids to waterborne Cd. -- Abstract: The olfactory system of salmonids is sensitive to the adverse effects of metals such as copper and cadmium. In the current study, we analyzed olfactory-mediated alarm responses, epithelial injury and recovery, and a suite of olfactory molecular biomarkers encoding genes critical in maintaining olfactory function in juvenile coho salmon receiving acute exposures to cadmium (Cd). The molecular biomarkers analyzed included four G-protein coupled receptors (GPCRs) representing the two major classes of odorant receptors (salmon olfactory receptor sorb and vomeronasal receptors svra, svrb, and gpr27), as well as markers of neurite outgrowth (nrn1) and antioxidant responses to metals, including heme oxygenase 1 (hmox1), and peroxiredoxin 1 (prdx1). Coho received acute (8–168 h) exposures to 3.7 ppb and 347 ppb Cd, and a subset of fish was analyzed following a 16-day depuration. Coho exposed to 347 ppb Cd over 48 h exhibited a reduction in freeze responses, and an extensive loss of olfaction accompanied by histological injury to the olfactory epithelium. The olfactory injury in coho exposed to 347 ppb Cd was accompanied at the gene level by significant decreases in expression of the olfactory GPCRs and increased expression of hmox1. Persistent behavioral deficits, histological injury and altered expression of a subset of olfactory biomarkers were still evident in Cd-exposed coho following a 16-day depuration in clean water. Exposure to 3.7 ppb Cd also resulted in reduced freeze responses and histological changes

  3. A novel neural substrate for the transformation of olfactory inputs into motor output.

    Directory of Open Access Journals (Sweden)

    Dominique Derjean

    2010-12-01

    Full Text Available It is widely recognized that animals respond to odors by generating or modulating specific motor behaviors. These reactions are important for daily activities, reproduction, and survival. In the sea lamprey, mating occurs after ovulated females are attracted to spawning sites by male sex pheromones. The ubiquity and reliability of olfactory-motor behavioral responses in vertebrates suggest tight coupling between the olfactory system and brain areas controlling movements. However, the circuitry and the underlying cellular neural mechanisms remain largely unknown. Using lamprey brain preparations, and electrophysiology, calcium imaging, and tract tracing experiments, we describe the neural substrate responsible for transforming an olfactory input into a locomotor output. We found that olfactory stimulation with naturally occurring odors and pheromones induced large excitatory responses in reticulospinal cells, the command neurons for locomotion. We have also identified the anatomy and physiology of this circuit. The olfactory input was relayed in the medial part of the olfactory bulb, in the posterior tuberculum, in the mesencephalic locomotor region, to finally reach reticulospinal cells in the hindbrain. Activation of this olfactory-motor pathway generated rhythmic ventral root discharges and swimming movements. Our study bridges the gap between behavior and cellular neural mechanisms in vertebrates, identifying a specific subsystem within the CNS, dedicated to producing motor responses to olfactory inputs.

  4. Spatial distribution of calcium-gated chloride channels in olfactory cilia.

    Science.gov (United States)

    French, Donald A; Badamdorj, Dorjsuren; Kleene, Steven J

    2010-12-30

    In vertebrate olfactory receptor neurons, sensory cilia transduce odor stimuli into changes in neuronal membrane potential. The voltage changes are primarily caused by the sequential openings of two types of channel: a cyclic-nucleotide-gated (CNG) cationic channel and a calcium-gated chloride channel. In frog, the cilia are 25 to 200 µm in length, so the spatial distributions of the channels may be an important determinant of odor sensitivity. To determine the spatial distribution of the chloride channels, we recorded from single cilia as calcium was allowed to diffuse down the length of the cilium and activate the channels. A computational model of this experiment allowed an estimate of the spatial distribution of the chloride channels. On average, the channels were concentrated in a narrow band centered at a distance of 29% of the ciliary length, measured from the base of the cilium. This matches the location of the CNG channels determined previously. This non-uniform distribution of transduction proteins is consistent with similar findings in other cilia. On average, the two types of olfactory transduction channel are concentrated in the same region of the cilium. This may contribute to the efficient detection of weak stimuli.

  5. Cooption of secretory phospholipase (SPLA2) for different aspects of gravity receptor-associated mineralization in vertebrate phylogeny

    Science.gov (United States)

    Thalmann, R.; Lu, W.

    2009-04-01

    Vertebrate gravity-associated minerals consists of either a single large stone (otolith), or an assembly of minute biomineral particles, otoconia ("ear dust"). Otoliths and both, amphibian and reptilian otoconia, consist of aragonite, whereas avian and mammalian otoconia consist of calcite. Vertebrate gravity-associated minerals are the product of site-directed biologically-controlled mineralization. Insoluble frame work molecules specify sites of nucleation and direction of crystal growth. Soluble matrix proteins modulate growth kinetics and crystal morphology. It is most remarkable that the principal insoluble frame work protein, otolin, is the same for both, otolith and otoconia. Otolin is a novel type of collagen, homologous to the network-forming collagen type X prevalent in mature chondrocytes. The principal soluble matrix proteins of calcitic, aragonitic, and most likely also of vateritic otoconia are all homologs of SPLA2, which is most prevalent in pancreatic secretion and snake venoms. Otonin90 (OC90), the principal soluble matrix protein of calcitic otoconia consists of two SPLA-like (SPLAL) domains, which are connected by a sizeable linker segment and contain significant terminal extensions. The MW of the protein backbone amounts to approximately 50 kDa. The molecule contains, in addition massive post-translational modifications, 80% of which are accounted for by sulfated GAGs, resulting in a total MW of 100 KDa. The protein backbone is moderately acidic, pI 4.4, but the pI of the whole molecule is 2.9, indicating a substantial acidity of the GAG component. In adapting SPLA2 for mineral modulation the enzymatic site is modified and presumed nonfunctional. The seven SH- bonds are rigorously conserved in both, OC90 and otoconin22 (OC22). It appears that the SH-bonds of the parent SPLA2 are intended to stabilize the molecule to ensure continued enzymatic activity in the hostile environment of the gut. It therefore seems logical that SPLA2 was coopted for

  6. Extrabulbar olfactory system and nervus terminalis FMRFamide immunoreactive components in Xenopus laevis ontogenesis.

    Science.gov (United States)

    Pinelli, Claudia; D'Aniello, Biagio; Polese, Gianluca; Rastogi, Rakesh K

    2004-09-01

    The extrabulbar olfactory system (EBOS) is a collection of nerve fibers which originate from primary olfactory receptor-like neurons and penetrate into the brain bypassing the olfactory bulbs. Our description is based upon the application of two neuronal tracers (biocytin, carbocyanine DiI) in the olfactory sac, at the cut end of the olfactory nerve and in the telencephalon of the developing clawed frog. The extrabulbar olfactory system was observed already at stage 45, which is the first developmental stage compatible with our techniques; at this stage, the extrabulbar olfactory system fibers terminated diffusely in the preoptic area. A little later in development, i.e. at stage 50, the extrabulbar olfactory system was maximally developed, extending as far caudally as the rhombencephalon. In the metamorphosing specimens, the extrabulbar olfactory system appeared reduced in extension; caudally, the fiber terminals did not extend beyond the diencephalon. While a substantial overlapping of biocytin/FMRFamide immunoreactivity was observed along the olfactory pathways as well as in the telencephalon, FMRFamide immunoreactivity was never observed to be colocalized in the same cellular or fiber components visualized by tracer molecules. The question whether the extrabulbar olfactory system and the nervus terminalis (NT) are separate anatomical entities or represent an integrated system is discussed.

  7. Changes in olfactory bulb volume following lateralized olfactory training.

    Science.gov (United States)

    Negoias, S; Pietsch, K; Hummel, T

    2017-08-01

    Repeated exposure to odors modifies olfactory function. Consequently, "olfactory training" plays a significant role in hyposmia treatment. In addition, numerous studies show that the olfactory bulb (OB) volume changes in disorders associated with olfactory dysfunction. Aim of this study was to investigate whether and how olfactory bulb volume changes in relation to lateralized olfactory training in healthy people. Over a period of 4 months, 97 healthy participants (63 females and 34 males, mean age: 23.74 ± 4.16 years, age range: 19-43 years) performed olfactory training by exposing the same nostril twice a day to 4 odors (lemon, rose, eucalyptus and cloves) while closing the other nostril. Before and after olfactory training, magnetic resonance imaging (MRI) scans were performed to measure OB volume. Furthermore, participants underwent lateralized odor threshold and odor identification testing using the "Sniffin' Sticks" test battery.OB volume increased significantly after olfactory training (11.3 % and 13.1 % respectively) for both trained and untrained nostril. No significant effects of sex, duration and frequency of training or age of the subjects were seen. Interestingly, PEA odor thresholds worsened after training, while olfactory identification remained unchanged.These data show for the first time in humans that olfactory training may involve top-down process, which ultimately lead to a bilateral increase in olfactory bulb volume.

  8. Associative cortex features in the first olfactory brain relay station.

    Science.gov (United States)

    Doucette, Wilder; Gire, David H; Whitesell, Jennifer; Carmean, Vanessa; Lucero, Mary T; Restrepo, Diego

    2011-03-24

    Synchronized firing of mitral cells (MCs) in the olfactory bulb (OB) has been hypothesized to help bind information together in olfactory cortex (OC). In this survey of synchronized firing by suspected MCs in awake, behaving vertebrates, we find the surprising result that synchronized firing conveys information on odor value ("Is it rewarded?") rather than odor identity ("What is the odor?"). We observed that as mice learned to discriminate between odors, synchronous firing responses to the rewarded and unrewarded odors became divergent. Furthermore, adrenergic blockage decreases the magnitude of odor divergence of synchronous trains, suggesting that MCs contribute to decision-making through adrenergic-modulated synchronized firing. Thus, in the olfactory system information on stimulus reward is found in MCs one synapse away from the sensory neuron. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Acetylcholine and Olfactory Perceptual Learning

    Science.gov (United States)

    Wilson, Donald A.; Fletcher, Max L.; Sullivan, Regina M.

    2004-01-01

    Olfactory perceptual learning is a relatively long-term, learned increase in perceptual acuity, and has been described in both humans and animals. Data from recent electrophysiological studies have indicated that olfactory perceptual learning may be correlated with changes in odorant receptive fields of neurons in the olfactory bulb and piriform…

  10. Localization of α1-2 Fucose Glycan in the Mouse Olfactory Pathway.

    Science.gov (United States)

    Kondoh, Daisuke; Kamikawa, Akihiro; Sasaki, Motoki; Kitamura, Nobuo

    2017-01-01

    Glycoconjugates in the olfactory system play critical roles in neuronal formation, and α1-2 fucose (α1-2Fuc) glycan mediates neurite outgrowth and synaptic plasticity. Histochemical findings of α1-2Fuc glycan in the mouse olfactory system detected using Ulex europaeus agglutinin-I (UEA-I) vary. This study histochemically assessed the main olfactory and vomeronasal pathways in male and female ICR and C57BL/6J mice aged 3-4 months using UEA-I. Ulex europaeus agglutinin-I reacted with most receptor cells arranged mainly at the basal region of the olfactory epithelium. The olfactory nerve layer and glomerular layer of the main olfactory bulb were speckled with positive UEA-I staining, and positive fibers were scattered from the glomerular to the internal plexiform layer. The lateral olfactory tract and rostral migratory stream were also positive for UEA-I. We identified superficial short-axon cells, interneurons of the external plexiform layer, external, middle and internal tufted cells, mitral cells and granule cells as the origins of the UEA-I-positive fibers in the main olfactory bulb. The anterior olfactory nucleus, anterior piriform cortex and olfactory tubercle were negative for UEA-I. Most receptor cells in the vomeronasal epithelium and most glomeruli of the accessory olfactory bulb were positive for UEA-I. Our findings indicated that α1-2Fuc glycan is located within the primary and secondary, but not the ternary, pathways of the main olfactory system, in local circuits of the main olfactory bulb and within the primary, but not secondary, pathway of the vomeronasal system. © 2016 S. Karger AG, Basel.

  11. Vertebral chondroblastoma

    International Nuclear Information System (INIS)

    Ilaslan, Hakan; Sundaram, Murali; Unni, Krishnan K.

    2003-01-01

    To determine the age distribution, gender, incidence, and imaging findings of vertebral chondroblastoma, and to compare our series with findings from case reports in the world literature.Design and patients Case records and imaging findings of nine histologically documented vertebral chondroblastomas were retrospectively reviewed for patient age, gender, vertebral column location and level, morphology, matrix, edema, soft tissue mass, spinal canal invasion, and metastases. Our findings were compared with a total of nine patients identified from previous publications in the world literature. The histologic findings in our cases was re-reviewed for diagnosis and specifically for features of calcification and secondary aneurysmal bone cyst (ABC). Clinical follow-up was requested from referring institutions. Nine of 856 chondroblastomas arose in vertebrae (incidence 1.4%; thoracic 5, lumbar 1, cervical 2, sacral 1). There were six males and three females ranging in age from 5 to 41 years (mean 28 years). Satisfactory imaging from seven patients revealed the tumor to arise from the posterior elements in four and the body in three. All tumors were expansive, six of seven were aggressive, and the spinal canal was significantly narrowed by bone or soft tissue mass in six. In one patient canal invasion was minimal. Calcification was pronounced in two and subtle in four. The sole nonaggressive-appearing tumor was heavily mineralized. Bony edema and secondary ABC were not seen on MR imaging. None of the cases had microscopic features of significant secondary ABC. Calcification, and specifically ''chicken wire'' calcification, was identified in two patients. Pulmonary metastases occurred in none. Vertebral chondroblastoma is a rare neoplasm that presents later in life than its appendicular counterpart. On imaging it is aggressive in appearance with bone destruction, soft tissue mass, and spinal canal invasion. The lesions contain variable amounts of mineral. Secondary

  12. Vertebral chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Ilaslan, Hakan; Sundaram, Murali [Department of Radiology, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905 (United States); Unni, Krishnan K. [Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905 (United States)

    2003-02-01

    To determine the age distribution, gender, incidence, and imaging findings of vertebral chondroblastoma, and to compare our series with findings from case reports in the world literature.Design and patients Case records and imaging findings of nine histologically documented vertebral chondroblastomas were retrospectively reviewed for patient age, gender, vertebral column location and level, morphology, matrix, edema, soft tissue mass, spinal canal invasion, and metastases. Our findings were compared with a total of nine patients identified from previous publications in the world literature. The histologic findings in our cases was re-reviewed for diagnosis and specifically for features of calcification and secondary aneurysmal bone cyst (ABC). Clinical follow-up was requested from referring institutions. Nine of 856 chondroblastomas arose in vertebrae (incidence 1.4%; thoracic 5, lumbar 1, cervical 2, sacral 1). There were six males and three females ranging in age from 5 to 41 years (mean 28 years). Satisfactory imaging from seven patients revealed the tumor to arise from the posterior elements in four and the body in three. All tumors were expansive, six of seven were aggressive, and the spinal canal was significantly narrowed by bone or soft tissue mass in six. In one patient canal invasion was minimal. Calcification was pronounced in two and subtle in four. The sole nonaggressive-appearing tumor was heavily mineralized. Bony edema and secondary ABC were not seen on MR imaging. None of the cases had microscopic features of significant secondary ABC. Calcification, and specifically ''chicken wire'' calcification, was identified in two patients. Pulmonary metastases occurred in none. Vertebral chondroblastoma is a rare neoplasm that presents later in life than its appendicular counterpart. On imaging it is aggressive in appearance with bone destruction, soft tissue mass, and spinal canal invasion. The lesions contain variable amounts of mineral

  13. Functional evidence of multidrug resistance transporters (MDR in rodent olfactory epithelium.

    Directory of Open Access Journals (Sweden)

    Adrien Molinas

    Full Text Available P-glycoprotein (Pgp and multidrug resistance-associated protein (MRP1 are membrane transporter proteins which function as efflux pumps at cell membranes and are considered to exert a protective function against the entry of xenobiotics. While evidence for Pgp and MRP transporter activity is reported for olfactory tissue, their possible interaction and participation in the olfactory response has not been investigated.Functional activity of putative MDR transporters was assessed by means of the fluorometric calcein acetoxymethyl ester (calcein-AM accumulation assay on acute rat and mouse olfactory tissue slices. Calcein-AM uptake was measured as fluorescence intensity changes in the presence of Pgp or MRP specific inhibitors. Epifluorescence microscopy measured time course analysis in the olfactory epithelium revealed significant inhibitor-dependent calcein uptake in the presence of each of the selected inhibitors. Furthermore, intracellular calcein accumulation in olfactory receptor neurons was also significantly increased in the presence of either one of the Pgp or MRP inhibitors. The presence of Pgp or MRP1 encoding genes in the olfactory mucosa of rat and mouse was confirmed by RT-PCR with appropriate pairs of species-specific primers. Both transporters were expressed in both newborn and adult olfactory mucosa of both species. To assess a possible involvement of MDR transporters in the olfactory response, we examined the electrophysiological response to odorants in the presence of the selected MDR inhibitors by recording electroolfactograms (EOG. In both animal species, MRPs inhibitors induced a marked reduction of the EOG magnitude, while Pgp inhibitors had only a minor or no measurable effect.The findings suggest that both Pgp and MRP transporters are functional in the olfactory mucosa and in olfactory receptor neurons. Pgp and MRPs may be cellular constituents of olfactory receptor neurons and represent potential mechanisms for modulation

  14. Conserved Fever Pathways across Vertebrates: A Herpesvirus Expressed Decoy TNF-α Receptor Delays Behavioral Fever in Fish.

    Science.gov (United States)

    Rakus, Krzysztof; Ronsmans, Maygane; Forlenza, Maria; Boutier, Maxime; Piazzon, M Carla; Jazowiecka-Rakus, Joanna; Gatherer, Derek; Athanasiadis, Alekos; Farnir, Frédéric; Davison, Andrew J; Boudinot, Pierre; Michiels, Thomas; Wiegertjes, Geert F; Vanderplasschen, Alain

    2017-02-08

    Both endotherms and ectotherms (e.g., fish) increase their body temperature to limit pathogen infection. Ectotherms do so by moving to warmer places, hence the term "behavioral fever." We studied the manifestation of behavioral fever in the common carp infected by cyprinid herpesvirus 3, a native carp pathogen. Carp maintained at 24°C died from the infection, whereas those housed in multi-chamber tanks encompassing a 24°C-32°C gradient migrated transiently to the warmest compartment and survived as a consequence. Behavioral fever manifested only at advanced stages of infection. Consistent with this, expression of CyHV-3 ORF12, encoding a soluble decoy receptor for TNF-α, delayed the manifestation of behavioral fever and promoted CyHV-3 replication in the context of a temperature gradient. Injection of anti-TNF-α neutralizing antibodies suppressed behavioral fever, and decreased fish survival in response to infection. This study provides a unique example of how viruses have evolved to alter host behavior to increase fitness. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  15. Direct transport of inhaled xylene and its metabolites from the olfactory mucosa to the glomeruli of the olfactory bulbs

    International Nuclear Information System (INIS)

    Lewis, J.L.; Dahl, A.R.; Kracko, D.A.

    1994-01-01

    The olfactory epithelium is a unique tissue in that single receptor neurons have dendrites in contact with the external environment at the nasal airway, and axon terminals that penetrate the cribriform plate and synapse in the olfactory bulb. The Central Nervous System (CNS) is protected from systematically circulating toxicants by a blood-brain barrier primarily composed of tight junctions between endothelial cells in cerebral vessels and a high metabolic capacity within these cells. No such barrier has yet been defined to protect the CNS from inhaled toxicants. Because all inhalants do not seem to access the CNS directly, a nose-brain barrier seems plausible. The purpose of the work described here is to determine whether or not a nose-brain barrier exists and to define its components. Although such a barrier is likely to be multi-faceted, the present work focuses only on the importance of gross histologic and metabolic characteristics of the olfactory epithelium in olfactory transport

  16. Increased Regenerative Capacity of the Olfactory Epithelium in Niemann–Pick Disease Type C1

    Directory of Open Access Journals (Sweden)

    Anja Meyer

    2017-04-01

    Full Text Available Niemann–Pick disease type C1 (NPC1 is a fatal neurovisceral lysosomal lipid storage disorder. The mutation of the NPC1 protein affects the homeostasis and transport of cholesterol and glycosphingolipids from late endosomes/lysosomes to the endoplasmic reticulum resulting in progressive neurodegeneration. Since olfactory impairment is one of the earliest symptoms in many neurodegenerative disorders, we focused on alterations of the olfactory epithelium in an NPC1 mouse model. Previous findings revealed severe morphological and immunohistochemical alterations in the olfactory system of NPC1−/− mutant mice compared with healthy controls (NPC1+/+. Based on immunohistochemical evaluation of the olfactory epithelium, we analyzed the impact of neurodegeneration in the olfactory epithelium of NPC1−/− mice and observed considerable loss of mature olfactory receptor neurons as well as an increased number of proliferating and apoptotic cells. Additionally, after administration of two different therapy approaches using either a combination of miglustat, 2-hydroxypropyl-β-cyclodextrin (HPβCD and allopregnanolone or a monotherapy with HPβCD, we recorded a remarkable reduction of morphological damages in NPC1−/− mice and an up to four-fold increase of proliferating cells within the olfactory epithelium. Numbers of mature olfactory receptor neurons doubled after both therapy approaches. Interestingly, we also observed therapy-induced alterations in treated NPC1+/+ controls. Thus, olfactory testing may provide useful information to monitor pharmacologic treatment approaches in human NPC1.

  17. Paradoxical mineralocorticoid receptor-mediated effect in fear memory encoding and expression of rats submitted to an olfactory fear conditioning task

    NARCIS (Netherlands)

    Souza, R.R.; Dal Bó, S.; de Kloet, E.R.; Oitzl, M.S.; Carobrez, A.P.

    2014-01-01

    There is general agreement that the substantial modification in memory and motivational states exerted by corticosteroids after a traumatic experience is mediated in complementary manner by the mineralocorticoid (MR) and glucocorticoid (GR) receptors. Here we tested the hypothesis that

  18. Evidence for a Peripheral Olfactory Memory in Imprinted Salmon

    Science.gov (United States)

    Nevitt, Gabrielle A.; Dittman, Andrew H.; Quinn, Thomas P.; Moody, William J., Jr.

    1994-05-01

    The remarkable homing ability of salmon relies on olfactory cues, but its cellular basis is unknown. To test the role of peripheral olfactory receptors in odorant memory retention, we imprinted coho salmon (Oncorhynchus kisutch) to micromolar concentrations of phenyl ethyl alcohol during parr-smolt transformation. The following year, we measured phenyl ethyl alcohol responses in the peripheral receptor cells using patch clamp. Cells from imprinted fish showed increased sensitivity to phenyl ethyl alcohol compared either to cells from naive fish or to sensitivity to another behaviorally important odorant (L-serine). Field experiments verified an increased behavioral preference for phenyl ethyl alcohol by imprinted salmon as adults. Thus, some component of the imprinted olfactory homestream memory appears to be retained peripherally.

  19. Atypical olfactory groove meningioma associated with uterine fibromatosis; case report

    Directory of Open Access Journals (Sweden)

    Toma I. Papacocea

    2016-11-01

    Full Text Available The concomitant presence of the olfactory groove meningioma with uterine fibrosis is very rare. Our report presents the case of a giant olfactory groove meningioma revealed after a uterine fibroma resection in a 44 years-old female, due to a generalized seizure 10 days after operation. Cranial CT-scan identified the tumor as an olfactory groove meningioma. The tumor was operated with a macroscopically complete resection; the endothermal coagulation of the dura attachment was performed (Simpson II with a good postoperative evolution. Laboratory results showed the presence of receptors for steroid hormones both in meningioma and uterine tumor, and the histopathological examination revealed an atypical meningioma with 17% proliferation markers. Our findings suggest that even though meningiomas are benign tumors and a complete resection usually indicates a good prognosis, the association with uterine fibromatosis and the presence of high percentage of steroid receptors creates a higher risk to relapse, imposing therefore a good monitoring.

  20. Uptake and transport of manganese in primary and secondary olfactory neurones in pike.

    Science.gov (United States)

    Tjälve, H; Mejàre, C; Borg-Neczak, K

    1995-07-01

    gamma-spectrometry and autoradiography were used to examine the axoplasmic flow of manganese in the olfactory nerves and to study the uptake of the metal in the brain after application of 54Mn2+ in the olfactory chambers of pikes. The results show that the 54Mn2+ is taken up in the olfactory receptor cells and is transported at a constant rate along the primary olfactory neurones into the brain. The maximal velocity for the transported 54Mn2+ was 2.90 +/- 0.21 mm/hr (mean +/- S.E.) at 10 degrees, which was the temperature used in the experiments. The 54Mn2+ accumulated in the entire olfactory bulbs, although most marked in central and caudal parts. The metal was also seen to migrate into large areas of the telencephalon, apparently mainly via the secondary olfactory axons present in the medial olfactory tract. A transfer along fibres of the medial olfactory tract probably also explains the labelling which was seen in the diencephalon down to the hypothalamus. The results also showed that there is a pathway connecting the two olfactory bulbs of the pike and that this can carry the metal. Our data further showed a marked accumulation of 54Mn2+ in the meningeal epithelium and in the contents of the meningeal sacs surrounding the olfactory bulbs. It appears from our study that manganese has the ability to pass the synaptic junctions between the primary and the secondary olfactory neurones in the olfactory bulbs and to migrate along secondary olfactory pathways into the telencephalon and the diencephalon.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Illuminating odors: when optogenetics brings to light unexpected olfactory abilities.

    Science.gov (United States)

    Grimaud, Julien; Lledo, Pierre-Marie

    2016-06-01

    For hundreds of years, the sense of smell has generated great interest in the world literature, oenologists, and perfume makers but less of scientists. Only recently this sensory modality has gained new attraction in neuroscience when original tools issued from physiology, anatomy, or molecular biology were available to decipher how the brain makes sense of olfactory cues. However, this move was promptly dampened by the difficulties of developing quantitative approaches to study the relationship between the physical characteristics of stimuli and the sensations they create. An upswing of olfactory investigations occurred when genetic tools could be used in combination with devices borrowed from the physics of light (a hybrid technique called optogenetics) to scrutinize the olfactory system and to provide greater physiological precision for studying olfactory-driven behaviors. This review aims to present the most recent studies that have used light to activate components of the olfactory pathway, such as olfactory receptor neurons, or neurons located further downstream, while leaving intact others brain circuits. With the use of optogenetics to unravel the mystery of olfaction, scientists have begun to disentangle how the brain makes sense of smells. In this review, we shall discuss how the brain recognizes odors, how it memorizes them, and how animals make decisions based on odorants they are capable of sensing. Although this review deals with olfaction, the role of light will be central throughout. © 2016 Grimaud and Lledo; Published by Cold Spring Harbor Laboratory Press.

  2. Illuminating odors: when optogenetics brings to light unexpected olfactory abilities

    Science.gov (United States)

    Grimaud, Julien

    2016-01-01

    For hundreds of years, the sense of smell has generated great interest in the world literature, oenologists, and perfume makers but less of scientists. Only recently this sensory modality has gained new attraction in neuroscience when original tools issued from physiology, anatomy, or molecular biology were available to decipher how the brain makes sense of olfactory cues. However, this move was promptly dampened by the difficulties of developing quantitative approaches to study the relationship between the physical characteristics of stimuli and the sensations they create. An upswing of olfactory investigations occurred when genetic tools could be used in combination with devices borrowed from the physics of light (a hybrid technique called optogenetics) to scrutinize the olfactory system and to provide greater physiological precision for studying olfactory-driven behaviors. This review aims to present the most recent studies that have used light to activate components of the olfactory pathway, such as olfactory receptor neurons, or neurons located further downstream, while leaving intact others brain circuits. With the use of optogenetics to unravel the mystery of olfaction, scientists have begun to disentangle how the brain makes sense of smells. In this review, we shall discuss how the brain recognizes odors, how it memorizes them, and how animals make decisions based on odorants they are capable of sensing. Although this review deals with olfaction, the role of light will be central throughout. PMID:27194792

  3. Olfactory aversive conditioning alters olfactory bulb mitral/tufted cell glomerular odor responses

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    2012-03-01

    Full Text Available The anatomical organization of receptor neuron input into the olfactory bulb (OB allows odor information to be transformed into an odorant-specific spatial map of mitral/tufted cell glomerular activity at the upper level of the olfactory bulb. In other sensory systems, neuronal representations of stimuli can be reorganized or enhanced following learning. While the mammalian OB has been shown to undergo experience-dependent plasticity at the glomerular level, it is still unclear if similar representational change occurs within mitral/tufted cell glomerular odor representations following learning. To address this, odorant-evoked glomerular activity patterns were imaged in mice expressing a GFP-based calcium indicator (GCaMP2 in OB mitral/tufted cells. Glomerular odor responses were imaged before and after olfactory associative conditioning to aversive foot shock. Following conditioning, we found no overall reorganization of the glomerular representation. Training, however, did significantly alter the amplitudes of individual glomeruli within the representation in mice in which the odor was presented together with foot shock. Further, the specific pairing of foot shock with odor presentations lead to increased responses primarily in initially weakly activated glomeruli. Overall, these results suggest that associative conditioning can enhance the initial representation of odors within the olfactory bulb by enhancing responses to the learned odor in some glomeruli.

  4. Olfactory interference during inhibitory backward pairing in honey bees.

    Directory of Open Access Journals (Sweden)

    Matthieu Dacher

    Full Text Available Restrained worker honey bees are a valuable model for studying the behavioral and neural bases of olfactory plasticity. The proboscis extension response (PER; the proboscis is the mouthpart of honey bees is released in response to sucrose stimulation. If sucrose stimulation is preceded one or a few times by an odor (forward pairing, the bee will form a memory for this association, and subsequent presentations of the odor alone are sufficient to elicit the PER. However, backward pairing between the two stimuli (sucrose, then odor has not been studied to any great extent in bees, although the vertebrate literature indicates that it elicits a form of inhibitory plasticity.If hungry bees are fed with sucrose, they will release a long lasting PER; however, this PER can be interrupted if an odor is presented 15 seconds (but not 7 or 30 seconds after the sucrose (backward pairing. We refer to this previously unreported process as olfactory interference. Bees receiving this 15 second backward pairing show reduced performance after a subsequent single forward pairing (excitatory conditioning trial. Analysis of the results supported a relationship between olfactory interference and a form of backward pairing-induced inhibitory learning/memory. Injecting the drug cimetidine into the deutocerebrum impaired olfactory interference.Olfactory interference depends on the associative link between odor and PER, rather than between odor and sucrose. Furthermore, pairing an odor with sucrose can lead either to association of this odor to PER or to the inhibition of PER by this odor. Olfactory interference may provide insight into processes that gate how excitatory and inhibitory memories for odor-PER associations are formed.

  5. Stimulus-response functions of single avian olfactory bulb neurones.

    Science.gov (United States)

    McKeegan, Dorothy E F; Demmers, Theodorus G M; Wathes, Christopher M; Jones, R Bryan; Gentle, Michael J

    2002-10-25

    This study investigated olfactory processing in a functional context by examining the responses of single avian olfactory bulb neurones to two biologically important gases over relevant concentration ranges. Recordings of extracellular spike activity were made from 80 single units in the left olfactory bulb of 11 anaesthetised, freely breathing adult hens (Gallus domesticus). The units were spontaneously active, exhibiting widely variable firing rates (0.07-47.28 spikes/s) and variable temporal firing patterns. Single units were tested for their response to an ascending concentration series of either ammonia (2.5-100 ppm) or hydrogen sulphide (1-50 ppm), delivered directly to the olfactory epithelium. Stimulation with a calibrated gas delivery system resulted in modification of spontaneous activity causing either inhibition (47% of units) or excitation (53%) of firing. For ammonia, 20 of the 35 units tested exhibited a response, while for hydrogen sulphide, 25 of the 45 units tested were responsive. Approximate response thresholds for ammonia (median threshold 3.75 ppm (range 2.5-60 ppm, n=20)) and hydrogen sulphide (median threshold 1 ppm (range 1-10 ppm, n=25)) were determined with most units exhibiting thresholds near the lower end of these ranges. Stimulus response curves were constructed for 23 units; 16 (the most complete) were subjected to a linear regression analysis to determine whether they were best fitted by a linear, log or power function. No single function provided the best fit for all the curves (seven were linear, eight were log, one was power). These findings show that avian units respond to changes in stimulus concentration in a manner generally consistent with reported responses in mammalian olfactory bulb neurones. However, this study illustrates a level of fine-tuning to small step changes in concentration (<5 ppm) not previously demonstrated in vertebrate single olfactory bulb neurones.

  6. A model of olfactory associative learning

    Science.gov (United States)

    Tavoni, Gaia; Balasubramanian, Vijay

    We propose a mechanism, rooted in the known anatomy and physiology of the vertebrate olfactory system, by which presentations of rewarded and unrewarded odors lead to formation of odor-valence associations between piriform cortex (PC) and anterior olfactory nucleus (AON) which, in concert with neuromodulators release in the bulb, entrains a direct feedback from the AON representation of valence to a group of mitral cells (MCs). The model makes several predictions concerning MC activity during and after associative learning: (a) AON feedback produces synchronous divergent responses in a localized subset of MCs; (b) such divergence propagates to other MCs by lateral inhibition; (c) after learning, MC responses reconverge; (d) recall of the newly formed associations in the PC increases feedback inhibition in the MCs. These predictions have been confirmed in disparate experiments which we now explain in a unified framework. For cortex, our model further predicts that the response divergence developed during learning reshapes odor representations in the PC, with the effects of (a) decorrelating PC representations of odors with different valences, (b) increasing the size and reliability of those representations, and enabling recall correction and redundancy reduction after learning. Simons Foundation for Mathematical Modeling of Living Systems.

  7. Identification and Comparison of Candidate Olfactory Genes in the Olfactory and Non-Olfactory Organs of Elm Pest Ambrostoma quadriimpressum (Coleoptera: Chrysomelidae) Based on Transcriptome Analysis.

    Science.gov (United States)

    Wang, Yinliang; Chen, Qi; Zhao, Hanbo; Ren, Bingzhong

    2016-01-01

    The leaf beetle Ambrostoma quadriimpressum (Coleoptera: Chrysomelidae) is a predominant forest pest that causes substantial damage to the lumber industry and city management. However, no effective and environmentally friendly chemical method has been discovered to control this pest. Until recently, the molecular basis of the olfactory system in A. quadriimpressum was completely unknown. In this study, antennae and leg transcriptomes were analyzed and compared using deep sequencing data to identify the olfactory genes in A. quadriimpressum. Moreover, the expression profiles of both male and female candidate olfactory genes were analyzed and validated by bioinformatics, motif analysis, homology analysis, semi-quantitative RT-PCR and RT-qPCR experiments in antennal and non-olfactory organs to explore the candidate olfactory genes that might play key roles in the life cycle of A. quadriimpressum. As a result, approximately 102.9 million and 97.3 million clean reads were obtained from the libraries created from the antennas and legs, respectively. Annotation led to 34344 Unigenes, which were matched to known proteins. Annotation data revealed that the number of genes in antenna with binding functions and receptor activity was greater than that of legs. Furthermore, many pathway genes were differentially expressed in the two organs. Sixteen candidate odorant binding proteins (OBPs), 10 chemosensory proteins (CSPs), 34 odorant receptors (ORs), 20 inotropic receptors [1] and 2 sensory neuron membrane proteins (SNMPs) and their isoforms were identified. Additionally, 15 OBPs, 9 CSPs, 18 ORs, 6 IRs and 2 SNMPs were predicted to be complete ORFs. Using RT-PCR, RT-qPCR and homology analysis, AquaOBP1/2/4/7/C1/C6, AquaCSP3/9, AquaOR8/9/10/14/15/18/20/26/29/33, AquaIR8a/13/25a showed olfactory-specific expression, indicating that these genes might play a key role in olfaction-related behaviors in A. quadriimpressum such as foraging and seeking. AquaOBP4/C5, AquaOBP4/C5, AquaCSP7

  8. Identification and Comparison of Candidate Olfactory Genes in the Olfactory and Non-Olfactory Organs of Elm Pest Ambrostoma quadriimpressum (Coleoptera: Chrysomelidae Based on Transcriptome Analysis.

    Directory of Open Access Journals (Sweden)

    Yinliang Wang

    Full Text Available The leaf beetle Ambrostoma quadriimpressum (Coleoptera: Chrysomelidae is a predominant forest pest that causes substantial damage to the lumber industry and city management. However, no effective and environmentally friendly chemical method has been discovered to control this pest. Until recently, the molecular basis of the olfactory system in A. quadriimpressum was completely unknown. In this study, antennae and leg transcriptomes were analyzed and compared using deep sequencing data to identify the olfactory genes in A. quadriimpressum. Moreover, the expression profiles of both male and female candidate olfactory genes were analyzed and validated by bioinformatics, motif analysis, homology analysis, semi-quantitative RT-PCR and RT-qPCR experiments in antennal and non-olfactory organs to explore the candidate olfactory genes that might play key roles in the life cycle of A. quadriimpressum. As a result, approximately 102.9 million and 97.3 million clean reads were obtained from the libraries created from the antennas and legs, respectively. Annotation led to 34344 Unigenes, which were matched to known proteins. Annotation data revealed that the number of genes in antenna with binding functions and receptor activity was greater than that of legs. Furthermore, many pathway genes were differentially expressed in the two organs. Sixteen candidate odorant binding proteins (OBPs, 10 chemosensory proteins (CSPs, 34 odorant receptors (ORs, 20 inotropic receptors [1] and 2 sensory neuron membrane proteins (SNMPs and their isoforms were identified. Additionally, 15 OBPs, 9 CSPs, 18 ORs, 6 IRs and 2 SNMPs were predicted to be complete ORFs. Using RT-PCR, RT-qPCR and homology analysis, AquaOBP1/2/4/7/C1/C6, AquaCSP3/9, AquaOR8/9/10/14/15/18/20/26/29/33, AquaIR8a/13/25a showed olfactory-specific expression, indicating that these genes might play a key role in olfaction-related behaviors in A. quadriimpressum such as foraging and seeking. AquaOBP4/C5, Aqua

  9. Modeling peripheral olfactory coding in Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Derek J Hoare

    Full Text Available The Drosophila larva possesses just 21 unique and identifiable pairs of olfactory sensory neurons (OSNs, enabling investigation of the contribution of individual OSN classes to the peripheral olfactory code. We combined electrophysiological and computational modeling to explore the nature of the peripheral olfactory code in situ. We recorded firing responses of 19/21 OSNs to a panel of 19 odors. This was achieved by creating larvae expressing just one functioning class of odorant receptor, and hence OSN. Odor response profiles of each OSN class were highly specific and unique. However many OSN-odor pairs yielded variable responses, some of which were statistically indistinguishable from background activity. We used these electrophysiological data, incorporating both responses and spontaneous firing activity, to develop a bayesian decoding model of olfactory processing. The model was able to accurately predict odor identity from raw OSN responses; prediction accuracy ranged from 12%-77% (mean for all odors 45.2% but was always significantly above chance (5.6%. However, there was no correlation between prediction accuracy for a given odor and the strength of responses of wild-type larvae to the same odor in a behavioral assay. We also used the model to predict the ability of the code to discriminate between pairs of odors. Some of these predictions were supported in a behavioral discrimination (masking assay but others were not. We conclude that our model of the peripheral code represents basic features of odor detection and discrimination, yielding insights into the information available to higher processing structures in the brain.

  10. Functional Reintegration of Sensory Neurons and Transitional Dendritic Reduction of Mitral/Tufted Cells during Injury-Induced Recovery of the Larval Xenopus Olfactory Circuit

    Directory of Open Access Journals (Sweden)

    Sara J. Hawkins

    2017-11-01

    Full Text Available Understanding the mechanisms involved in maintaining lifelong neurogenesis has a clear biological and clinical interest. In the present study, we performed olfactory nerve transection on larval Xenopus to induce severe damage to the olfactory circuitry. We surveyed the timing of the degeneration, subsequent rewiring and functional regeneration of the olfactory system following injury. A range of structural labeling techniques and functional calcium imaging were performed on both tissue slices and whole brain preparations. Cell death of olfactory receptor neurons and proliferation of stem cells in the olfactory epithelium were immediately increased following lesion. New olfactory receptor neurons repopulated the olfactory epithelium and once again showed functional responses to natural odorants within 1 week after transection. Reinnervation of the olfactory bulb (OB by newly formed olfactory receptor neuron axons also began at this time. Additionally, we observed a temporary increase in cell death in the OB and a subsequent loss in OB volume. Mitral/tufted cells, the second order neurons of the olfactory system, largely survived, but transiently lost dendritic tuft complexity. The first odorant-induced responses in the OB were observed 3 weeks after nerve transection and the olfactory network showed signs of major recovery, both structurally and functionally, after 7 weeks.

  11. Processing of Sensory Information in the Olfactory System

    DEFF Research Database (Denmark)

    The olfactory system is an attractive model system due to the easy control of sensory input and the experimental accessibility in animal studies. The odorant signals are processed from receptor neurons to a neural network of mitral and granular cells while various types of nonlinear behaviour can...... and equation-free techniques allow for a better reproduction and understanding of recent experimental findings. Talks: Olfaction as a Model System for Sensory-Processing Neural Networks (Jens Midtgaard, University of Copenhagen, Denmark) Nonlinear Effects of Signal Transduction in Olfactory Sensory Neurons...

  12. A Robust Feedforward Model of the Olfactory System.

    Directory of Open Access Journals (Sweden)

    Yilun Zhang

    2016-04-01

    Full Text Available Most natural odors have sparse molecular composition. This makes the principles of compressed sensing potentially relevant to the structure of the olfactory code. Yet, the largely feedforward organization of the olfactory system precludes reconstruction using standard compressed sensing algorithms. To resolve this problem, recent theoretical work has shown that signal reconstruction could take place as a result of a low dimensional dynamical system converging to one of its attractor states. However, the dynamical aspects of optimization slowed down odor recognition and were also found to be susceptible to noise. Here we describe a feedforward model of the olfactory system that achieves both strong compression and fast reconstruction that is also robust to noise. A key feature of the proposed model is a specific relationship between how odors are represented at the glomeruli stage, which corresponds to a compression, and the connections from glomeruli to third-order neurons (neurons in the olfactory cortex of vertebrates or Kenyon cells in the mushroom body of insects, which in the model corresponds to reconstruction. We show that should this specific relationship hold true, the reconstruction will be both fast and robust to noise, and in particular to the false activation of glomeruli. The predicted connectivity rate from glomeruli to third-order neurons can be tested experimentally.

  13. Olfactory dysfunction in neuromyelitis optica spectrum disorders

    NARCIS (Netherlands)

    Zhang, L.J.; Zhao, N.; Fu, Y.; Zhang, D.Q.; Wang, J.; Qin, W.; Zhang, N.N.N.; Wood, K.; Liu, Y.; Yu, C.S.; Shi, F.D.; Yang, L.

    2015-01-01

    Few data were available for the understanding of olfactory function in neuromyelitis optica spectrum disorders (NMOSDs). The aims of our study were to investigate the incidence of olfactory dysfunction and characterize olfactory structures, using MRI, in patients with NMOSDs. Olfactory function was

  14. The role of dopamine in Drosophila larval classical olfactory conditioning.

    Directory of Open Access Journals (Sweden)

    Mareike Selcho

    Full Text Available Learning and memory is not an attribute of higher animals. Even Drosophila larvae are able to form and recall an association of a given odor with an aversive or appetitive gustatory reinforcer. As the Drosophila larva has turned into a particularly simple model for studying odor processing, a detailed neuronal and functional map of the olfactory pathway is available up to the third order neurons in the mushroom bodies. At this point, a convergence of olfactory processing and gustatory reinforcement is suggested to underlie associative memory formation. The dopaminergic system was shown to be involved in mammalian and insect olfactory conditioning. To analyze the anatomy and function of the larval dopaminergic system, we first characterize dopaminergic neurons immunohistochemically up to the single cell level and subsequent test for the effects of distortions in the dopamine system upon aversive (odor-salt as well as appetitive (odor-sugar associative learning. Single cell analysis suggests that dopaminergic neurons do not directly connect gustatory input in the larval suboesophageal ganglion to olfactory information in the mushroom bodies. However, a number of dopaminergic neurons innervate different regions of the brain, including protocerebra, mushroom bodies and suboesophageal ganglion. We found that dopamine receptors are highly enriched in the mushroom bodies and that aversive and appetitive olfactory learning is strongly impaired in dopamine receptor mutants. Genetically interfering with dopaminergic signaling supports this finding, although our data do not exclude on naïve odor and sugar preferences of the larvae. Our data suggest that dopaminergic neurons provide input to different brain regions including protocerebra, suboesophageal ganglion and mushroom bodies by more than one route. We therefore propose that different types of dopaminergic neurons might be involved in different types of signaling necessary for aversive and appetitive

  15. Neuronal basis of innate olfactory attraction to ethanol in Drosophila.

    Directory of Open Access Journals (Sweden)

    Andrea Schneider

    Full Text Available The decision to move towards a mating partner or a food source is essential for life. The mechanisms underlying these behaviors are not well understood. Here, we investigated the role of octopamine - the invertebrate analogue of noradrenaline - in innate olfactory attraction to ethanol. We confirmed that preference is caused via an olfactory stimulus by dissecting the function of the olfactory co-receptor Orco (formally known as OR83b. Orco function is not required for ethanol recognition per se, however it plays a role in context dependent recognition of ethanol. Odor-evoked ethanol preference requires the function of Tbh (Tyramine β hydroxalyse, the rate-limiting enzyme of octopamine synthesis. In addition, neuronal activity in a subset of octopaminergic neurons is necessary for olfactory ethanol preference. Notably, a specific neuronal activation pattern of tyraminergic/octopaminergic neurons elicit preference and is therefore sufficient to induce preference. In contrast, dopamine dependent increase in locomotor activity is not sufficient for olfactory ethanol preference. Consistent with the role of noradrenaline in mammalian drug induced rewards, we provide evidence that in adult Drosophila the octopaminergic neurotransmitter functions as a reinforcer and that the molecular dissection of the innate attraction to ethanol uncovers the basic properties of a response selection system.

  16. From chemical neuroanatomy to an understanding of the olfactory system

    Directory of Open Access Journals (Sweden)

    L. Oboti

    2011-10-01

    Full Text Available The olfactory system is the appropriate model for studying several aspects of neuronal physiology spanning from the developmental stage to neural network remodelling in the adult brain. Both the morphological and physiological understanding of this system were strongly supported by classical histochemistry. It is emblematic the case of the Olfactory Marker Protein (OMP staining, the first, powerful marker for fully differentiated olfactory receptor neurons and a key tool to investigate the dynamic relations between peripheral sensory epithelia and central relay regions given its presence within olfactory fibers reaching the olfactory bulb (OB. Similarly, the use of thymidine analogues was able to show neurogenesis in an adult mammalian brain far before modern virus labelling and lipophilic tracers based methods. Nowadays, a wealth of new histochemical techniques combining cell and molecular biology approaches is available, giving stance to move from the analysis of the chemically identified circuitries to functional research. The study of adult neurogenesis is indeed one of the best explanatory examples of this statement. After defining the cell types involved and the basic physiology of this phenomenon in the OB plasticity, we can now analyze the role of neurogenesis in well testable behaviours related to socio-chemical communication in rodents.

  17. From chemical neuroanatomy to an understanding of the olfactory system

    Science.gov (United States)

    Oboti, L.; Peretto, P.; De Marchis, S.; Fasolo, A.

    2011-01-01

    The olfactory system of mammals is the appropriate model for studying several aspects of neuronal physiology spanning from the developmental stage to neural network remodelling in the adult brain. Both the morphological and physiological understanding of this system were strongly supported by classical histochemistry. It is emblematic the case of the Olfactory Marker Protein (OMP) staining, the first, powerful marker for fully differentiated olfactory receptor neurons and a key tool to investigate the dynamic relations between peripheral sensory epithelia and central relay regions given its presence within olfactory fibers reaching the olfactory bulb (OB). Similarly, the use of thymidine analogues was able to show neurogenesis in an adult mammalian brain far before modern virus labelling and lipophilic tracers based methods. Nowadays, a wealth of new histochemical techniques combining cell and molecular biology approaches is available, giving stance to move from the analysis of the chemically identified circuitries to functional research. The study of adult neurogenesis is indeed one of the best explanatory examples of this statement. After defining the cell types involved and the basic physiology of this phenomenon in the OB plasticity, we can now analyze the role of neurogenesis in well testable behaviours related to socio-chemical communication in rodents. PMID:22297441

  18. Immunocytochemistry of the olfactory marker protein.

    Science.gov (United States)

    Monti-Graziadei, G A; Margolis, F L; Harding, J W; Graziadei, P P

    1977-12-01

    The olfactory marker protein has been localized, by means of immunohistochemical techniques in the primary olfactory neurons of mice. The olfactory marker protein is not present in the staminal cells of the olfactory neuroepithelium, and the protein may be regarded as indicative of the functional stage of the neurons. Our data indicate that the olfactory marker protein is present in the synaptic terminals of the olfactory neurons at the level of the olfactory bulb glomeruli. The postsynaptic profiles of both mitral and periglomerular cells are negative.

  19. Origins of gonadotropin-releasing hormone (GnRH) in vertebrates: identification of a novel GnRH in a basal vertebrate, the sea lamprey.

    Science.gov (United States)

    Kavanaugh, Scott I; Nozaki, Masumi; Sower, Stacia A

    2008-08-01

    We cloned a cDNA encoding a novel (GnRH), named lamprey GnRH-II, from the sea lamprey, a basal vertebrate. The deduced amino acid sequence of the newly identified lamprey GnRH-II is QHWSHGWFPG. The architecture of the precursor is similar to that reported for other GnRH precursors consisting of a signal peptide, decapeptide, a downstream processing site, and a GnRH-associated peptide; however, the gene for lamprey GnRH-II does not have introns in comparison with the gene organization for all other vertebrate GnRHs. Lamprey GnRH-II precursor transcript was widely expressed in a variety of tissues. In situ hybridization of the brain showed expression and localization of the transcript in the hypothalamus, medulla, and olfactory regions, whereas immunohistochemistry using a specific antiserum showed only GnRH-II cell bodies and processes in the preoptic nucleus/hypothalamus areas. Lamprey GnRH-II was shown to stimulate the hypothalamic-pituitary axis using in vivo and in vitro studies. Lamprey GnRH-II was also shown to activate the inositol phosphate signaling system in COS-7 cells transiently transfected with the lamprey GnRH receptor. These studies provide evidence for a novel lamprey GnRH that has a role as a third hypothalamic GnRH. In summary, the newly discovered lamprey GnRH-II offers a new paradigm of the origin of the vertebrate GnRH family. We hypothesize that due to a genome/gene duplication event, an ancestral gene gave rise to two lineages of GnRHs: the gnathostome GnRH and lamprey GnRH-II.

  20. Morphological study on the olfactory systems of the snapping turtle, Chelydra serpentina.

    Science.gov (United States)

    Nakamuta, Nobuaki; Nakamuta, Shoko; Kato, Hideaki; Yamamoto, Yoshio

    2016-06-01

    In this study, the olfactory system of a semi-aquatic turtle, the snapping turtle, has been morphologically investigated by electron microscopy, immunohistochemistry, and lectin histochemistry. The nasal cavity of snapping turtle was divided into the upper and lower chambers, lined by the sensory epithelium containing ciliated and non-ciliated olfactory receptor neurons, respectively. Each neuron expressed both Gαolf, the α-subunit of G-proteins coupling to the odorant receptors, and Gαo, the α-subunit of G-proteins coupling to the type 2 vomeronasal receptors. The axons originating from the upper chamber epithelium projected to the ventral part of the olfactory bulb, while those from the lower chamber epithelium to the dorsal part of the olfactory bulb. Despite the identical expression of G-protein α-subunits in the olfactory receptor neurons, these two projections were clearly distinguished from each other by the differential expression of glycoconjugates. In conclusion, these data indicate the presence of two types of olfactory systems in the snapping turtle. Topographic arrangement of the upper and lower chambers and lack of the associated glands in the lower chamber epithelium suggest their possible involvement in the detection of odorants: upper chamber epithelium in the air and the lower chamber epithelium in the water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Heterogeneous sensory innervation and extensive intrabulbar connections of olfactory necklace glomeruli.

    Directory of Open Access Journals (Sweden)

    Renee E Cockerham

    Full Text Available The mammalian nose employs several olfactory subsystems to recognize and transduce diverse chemosensory stimuli. These subsystems differ in their anatomical position within the nasal cavity, their targets in the olfactory forebrain, and the transduction mechanisms they employ. Here we report that they can also differ in the strategies they use for stimulus coding. Necklace glomeruli are the sole main olfactory bulb (MOB targets of an olfactory sensory neuron (OSN subpopulation distinguished by its expression of the receptor guanylyl cyclase GC-D and the phosphodiesterase PDE2, and by its chemosensitivity to the natriuretic peptides uroguanylin and guanylin and the gas CO(2. In stark contrast to the homogeneous sensory innervation of canonical MOB glomeruli from OSNs expressing the same odorant receptor (OR, we find that each necklace glomerulus of the mouse receives heterogeneous innervation from at least two distinct sensory neuron populations: one expressing GC-D and PDE2, the other expressing olfactory marker protein. In the main olfactory system it is thought that odor identity is encoded by a combinatorial strategy and represented in the MOB by a pattern of glomerular activation. This combinatorial coding scheme requires functionally homogeneous sensory inputs to individual glomeruli by OSNs expressing the same OR and displaying uniform stimulus selectivity; thus, activity in each glomerulus reflects the stimulation of a single OSN type. The heterogeneous sensory innervation of individual necklace glomeruli by multiple, functionally distinct, OSN subtypes precludes a similar combinatorial coding strategy in this olfactory subsystem.

  2. An olfactory cocktail party: figure-ground segregation of odorants in rodents.

    Science.gov (United States)

    Rokni, Dan; Hemmelder, Vivian; Kapoor, Vikrant; Murthy, Venkatesh N

    2014-09-01

    In odorant-rich environments, animals must be able to detect specific odorants of interest against variable backgrounds. However, studies have found that both humans and rodents are poor at analyzing the components of odorant mixtures, suggesting that olfaction is a synthetic sense in which mixtures are perceived holistically. We found that mice could be easily trained to detect target odorants embedded in unpredictable and variable mixtures. To relate the behavioral performance to neural representation, we imaged the responses of olfactory bulb glomeruli to individual odors in mice expressing the Ca(2+) indicator GCaMP3 in olfactory receptor neurons. The difficulty of segregating the target from the background depended strongly on the extent of overlap between the glomerular responses to target and background odors. Our study indicates that the olfactory system has powerful analytic abilities that are constrained by the limits of combinatorial neural representation of odorants at the level of the olfactory receptors.

  3. Ancient protostome origin of chemosensory ionotropic glutamate receptors and the evolution of insect taste and olfaction.

    Directory of Open Access Journals (Sweden)

    Vincent Croset

    2010-08-01

    Full Text Available Ionotropic glutamate receptors (iGluRs are a highly conserved family of ligand-gated ion channels present in animals, plants, and bacteria, which are best characterized for their roles in synaptic communication in vertebrate nervous systems. A variant subfamily of iGluRs, the Ionotropic Receptors (IRs, was recently identified as a new class of olfactory receptors in the fruit fly, Drosophila melanogaster, hinting at a broader function of this ion channel family in detection of environmental, as well as intercellular, chemical signals. Here, we investigate the origin and evolution of IRs by comprehensive evolutionary genomics and in situ expression analysis. In marked contrast to the insect-specific Odorant Receptor family, we show that IRs are expressed in olfactory organs across Protostomia--a major branch of the animal kingdom that encompasses arthropods, nematodes, and molluscs--indicating that they represent an ancestral protostome chemosensory receptor family. Two subfamilies of IRs are distinguished: conserved "antennal IRs," which likely define the first olfactory receptor family of insects, and species-specific "divergent IRs," which are expressed in peripheral and internal gustatory neurons, implicating this family in taste and food assessment. Comparative analysis of drosophilid IRs reveals the selective forces that have shaped the repertoires in flies with distinct chemosensory preferences. Examination of IR gene structure and genomic distribution suggests both non-allelic homologous recombination and retroposition contributed to the expansion of this multigene family. Together, these findings lay a foundation for functional analysis of these receptors in both neurobiological and evolutionary studies. Furthermore, this work identifies novel targets for manipulating chemosensory-driven behaviours of agricultural pests and disease vectors.

  4. Biochemistry of an olfactory purinergic system: dephosphorylation of excitatory nucleotides and uptake of adenosine

    Energy Technology Data Exchange (ETDEWEB)

    Trapido-Rosenthal, H G; Carr, W E; Gleeson, R A

    1987-10-01

    The olfactory organ of the spiny lobster, Panulirus argus, is composed of chemosensory sensilla containing the dendrites of primary chemosensory neurons. Receptors on these dendrites are activated by the nucleotides AMP, ADP, and ATP but not by the nucleoside adenosine. It is shown here that the lobster chemosensory sensilla contain enzymes that dephosphorylate excitatory nucleotides and an uptake system that internalizes the nonexcitatory dephosphorylated product adenosine. The uptake of (/sup 3/H)-adenosine is saturable with increasing concentration, linear with time for up to 3 h, sodium dependent, insensitive to moderate pH changes and has a Km of 7.1 microM and a Vmax of 5.2 fmol/sensillum/min (573 fmol/micrograms of protein/min). Double-label experiments show that sensilla dephosphorylate nucleotides extracellularly; /sup 3/H from adenine-labeled AMP or ATP is internalized, whereas 32P from phosphate-labeled nucleotides is not. The dephosphorylation of AMP is very rapid; /sup 3/H from AMP is internalized at the same rate as /sup 3/H from adenosine. Sensillar 5'-ectonucleotidase activity is inhibited by ADP and the ADP analog alpha, beta-methylene ADP. Collectively, these results indicate that the enzymes and the uptake system whereby chemosensory sensilla of the lobster inactivate excitatory nucleotides and clear adenosine from extracellular spaces are very similar to those present in the internal tissues of vertebrates, where nucleotides have many neuroactive effects.

  5. V. Terrestrial vertebrates

    Science.gov (United States)

    Dean Pearson; Deborah Finch

    2011-01-01

    Within the Interior West, terrestrial vertebrates do not represent a large number of invasive species relative to invasive weeds, aquatic vertebrates, and invertebrates. However, several invasive terrestrial vertebrate species do cause substantial economic and ecological damage in the U.S. and in this region (Pimental 2000, 2007; Bergman and others 2002; Finch and...

  6. Discordance between olfactory psychophysical measurements and olfactory event related potentials in five patients with olfactory dysfunction following upper respiratory infection.

    Science.gov (United States)

    Guan, Jing; Ni, Dao-feng; Wang, Jian; Gao, Zhi-qiang

    2009-07-05

    Subjective olfactory tests are easy to perform and popularly applied in the clinic, but using only these, it is difficult to diagnose all disorders of the olfactory system. The olfactory event related potentials technique offers further insight into the olfactory system and is an ideal objective test. This analysis was of subjective and objective data on the olfactory function of twelve patients with loss of smell associated with an upper respiratory infection (URI). We tested the twelve patients with URI induced olfactory loss by medical history, physical examination of the head and neck, olfactory tests and medical imaging. Olfactory function was assessed by Toyota and Takagi olfactometry including olfactory detection and recognition thresholds and olfactory event-related potentials (OERPs) recorded with OEP-98C Olfactometer. An unusual phenomenon was observed in five patients in whom the subjective detection and recognition thresholds were normal, while the expected OERPs were not detectable. We suggest that the discordance between olfactory psychophysical measurements and OERPs might be the results of abnormal electrophysiology related with olfactory neuropathy caused by viral URI. In addition, the measurement of OERPs might play a significant role in evaluating olfactory dysfunction.

  7. Discordance between olfactory psychophysical measurements and olfactory event related potentials in five patients with olfactory dysfunction following upper respiratory infection

    Institute of Scientific and Technical Information of China (English)

    GUAN Jing; NI Dao-feng; WANG Jian; GAO Zhi-qiang

    2009-01-01

    Background Subjective olfactory tests are easy to perform and popularly applied in the clinic, but using only these, it is difficult to diagnose all disorders of the olfactory system. The olfactory event related potentials technique offers further insight into the olfactory system and is an ideal objective test. This analysis was of subjective and objective data on the olfactory function of twelve patients with loss of smell associated with an upper respiratory infection (URI). Methods We tested the twelve patients with URI induced olfactory loss by medical history, physical examination of the head and neck, olfactory tests and medical imaging. Olfactory function was assessed by Toyota and Takagi olfactometry including olfactory detection and recognition thresholds and olfactory event-related potentials (OERPs) recorded with OEP-98C Olfactometer. Results An unusual phenomenon was observed in five patients in whom the subjective detection and recognition thresholds were normal, while the expected OERPs were not detectable. Conclusions We suggest that the discordance between olfactory psychophysical measurements and OERPs might be the results of abnormal electrephysiology related with olfactory neuropathy caused by viral URI. In addition, the measurement of OERPs might play a significant role in evaluating olfactory dysfunction.

  8. Contaminant exposure in terrestrial vertebrates

    International Nuclear Information System (INIS)

    Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.

    2007-01-01

    Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

  9. Neuropeptide Y in the olfactory system, forebrain and pituitary of the teleost, Clarias batrachus.

    Science.gov (United States)

    Gaikwad, Archana; Biju, K C; Saha, Subhash G; Subhedar, Nishikant

    2004-03-01

    Distribution of neuropeptide Y (NPY)-like immunoreactivity in the forebrain of catfish Clarias batrachus was examined with immunocytochemistry. Conspicuous immunoreactivity was seen in the olfactory receptor neurons (ORNs), their projections in the olfactory nerve, fascicles of the olfactory nerve layer in the periphery of bulb and in the medial olfactory tracts as they extend to the telencephalic lobes. Ablation of the olfactory organ resulted in loss of immunoreactivity in the olfactory nerve layer of the bulb and also in the fascicles of the medial olfactory tracts. This evidence suggests that NPY may serve as a neurotransmitter in the ORNs and convey chemosensory information to the olfactory bulb, and also to the telencephalon over the extrabulbar projections. In addition, network of beaded immunoreactive fibers was noticed throughout the olfactory bulb, which did not respond to ablation experiment. These fibers may represent centrifugal innervation of the bulb. Strong immunoreactivity was encountered in some ganglion cells of nervus terminalis. Immunoreactive fibers and terminal fields were widely distributed in the telencephalon. Several neurons of nucleus entopeduncularis were moderately immunoreactive; and a small population of neurons in nucleus preopticus periventricularis was also labeled. Immunoreactive terminal fields were particularly conspicuous in the preoptic, the tuberal areas, and the periventricular zone around the third ventricle and inferior lobes. NPY immunoreactive cells and fibers were detected in all the lobes of the pituitary gland. Present results describing the localization of NPY in the forebrain of C. batrachus are in concurrence with the pattern of the immunoreactivity encountered in other teleosts. However, NPY in olfactory system of C. batrachus is a novel feature that suggests a role for the peptide in processing of chemosensory information.

  10. Aversive cues fail to activate fos expression in the asymmetric olfactory-habenula pathway of zebrafish

    Directory of Open Access Journals (Sweden)

    Tagide N. Decarvalho

    2013-05-01

    Full Text Available The dorsal habenular nuclei of the zebrafish epithalamus have become a valuable model for studying the development of left-right (L-R asymmetry and its function in the vertebrate brain. The bilaterally paired dorsal habenulae exhibit striking differences in size, neuroanatomical organization and molecular properties. They also display differences in their efferent connections with the interpeduncular nucleus (IPN and in their afferent input, with a subset of mitral cells distributed on both sides of the olfactory bulb innervating only the right habenula. Previous studies have implicated the dorsal habenulae in modulating fear/anxiety responses in juvenile and adult zebrafish. It has been suggested that the asymmetric olfactory-habenula pathway (OB-Ha, revealed by selective labeling from an lhx2a:YFP transgene, mediates fear behaviors elicited by alarm pheromone. Here we show that expression of the fam84b gene demarcates a unique region of the right habenula that is the site of innervation by lhx2a:YFP-labeled olfactory axons. Upon ablation of the parapineal, which normally promotes left habenular identity; the fam84b domain is present in both dorsal habenulae and lhx2a:YFP-labeled olfactory bulb neurons form synapses on the left and the right side. To explore the relevance of the asymmetric olfactory projection and how it might influence habenular function, we tested activation of this pathway using odorants known to evoke behaviors. We find that alarm substance or other aversive odors, and attractive cues, activate fos expression in subsets of cells in the olfactory bulb but not in the lhx2a:YFP expressing population. Moreover, neither alarm pheromone nor chondroitin sulfate elicited fos activation in the dorsal habenulae. The results indicate that L-R asymmetry of the epithalamus sets the directionality of olfactory innervation, however, the lhx2a:YFP olfactory-habenula pathway does not appear to mediate fear responses to aversive odorants.

  11. Olfactory groove meningiomas.

    Science.gov (United States)

    Hentschel, Stephen J; DeMonte, Franco

    2003-06-15

    Olfactory groove meningiomas (OGMs) arise over the cribriform plate and may reach very large sizes prior to presentation. They can be differentiated from tuberculum sellae meningiomas because OGMs arise more anterior in the skull base and displace the optic nerve and chiasm inferiorly rather than superiorly. The authors searched the neurosurgery database at the M. D. Anderson Cancer Center for cases of OGM treated between 1993 and 2003. The records of these patients were then reviewed retrospectively for details regarding clinical presentation, imaging findings, surgical results and complications, and follow-up status. Thirteen patients, (12 women and one man, mean age 56 years) harbored OGMs (mean size 5.7 cm). All patients underwent bifrontal craniotomies and biorbital osteotomies. There were 11 complete resections (including the hyperostotic bone and dura of the cribriform plate and any extension into the ethmoid sinuses) and two subtotal resections with minimal residual tumor left in patients with recurrent lesions. No complication directly due to the surgery occurred in any patient. There were no recurrences in a mean follow-up period of 2 years (range 0-5 years). With current microsurgical techniques, the results of OGM resection are excellent, with a high rate of total resection and a low incidence of complications. All hyperostotic bone should be removed with the dura of the anterior skull base to minimize the risk of recurrence.

  12. Histomorphological and microanatomical characteristics of the olfactory organ of freshwater carp, Cirrhinus reba (Hamilton

    Directory of Open Access Journals (Sweden)

    Ghosh Saroj Kumar

    2016-12-01

    Full Text Available The morphoanatomy, cellular organization, and surface architecture of the olfactory apparatus in Cirrhinus reba (Hamilton is described using light and scanning electron microscopy. The oval shaped olfactory rosette contained 32 ± 2 primary lamellae on each side of the median raphe, and was lodged on the floor of the olfactory chamber. The olfactory lamellae were basically flat and compactly arranged in the rosette. The olfactory chamber communicated to the outside aquatic environment through inlet and outlet apertures with a conspicuous nasal flap in between. The mid dorsal portion of the olfactory lamellae was characterized by a linguiform process. Sensory and non-sensory regions were distributed separately on each lamella. The sensory epithelium occupied the apical part including the linguiform process, whereas the resting part of the lamella was covered with non-sensory epithelium. The sensory epithelium comprised both ciliated and microvillous receptor cells distinguished by the architecture on their apical part. The non-sensory epithelium possessed mucous cells, labyrinth cells, and stratified epithelial cells with distinctive microridges. The functional importance of the different cells lining the olfactory mucosa was correlated with the ecological habits of the fish examined.

  13. Gross anatomy and histology of the olfactory rosette of the shark Heptranchias perlo.

    Science.gov (United States)

    Ferrando, Sara; Gallus, Lorenzo; Amaroli, Andrea; Gambardella, Chiara; Waryani, Baradi; Di Blasi, Davide; Vacchi, Marino

    2017-06-01

    Sharks belonging to the family Hexanchidae have six or seven gill slits, unlike all other elasmobranchs, which have five gill slits. Their olfactory organs have a round shape, which is common for holocephalans, but not for elasmobranchs. Thus, the shape of the olfactory organ represents a further, less striking, peculiarity of this family among elasmobranchs. Despite that, the microscopic anatomy and histology of the olfactory organ have not yet been studied in any species of this family. Here, an anatomical and histological description of the olfactory organ of the sharpnose sevengill shark Heptranchias perlo is given. The organ is a rosette, with a central raphe and 31-34 primary lamellae, which bear secondary lamellae with a more or less branched shape. The elastic connective capsule which envelops the olfactory rosette possibly changes its shape along with water influx. In the olfactory epithelium, the supporting cells also have a secretory function, while no specialized mucous cells are visible; regarding this feature the olfactory epithelium of H. perlo differs from that of other chondrichthyan species. The immunohistochemical investigation of the sensory epithelium shows the absence of immunoreactivity for Gαolf in receptor neurons, which confirms previous observations in Chondrichthyes. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Peripheral and Central Olfactory Tuning in a Moth

    Science.gov (United States)

    Ong, Rose C.

    2012-01-01

    Animals can be innately attracted to certain odorants. Because these attractants are particularly salient, they might be expected to induce relatively strong responses throughout the olfactory pathway, helping animals detect the most relevant odors but limiting flexibility to respond to other odors. Alternatively, specific neural wiring might link innately preferred odors to appropriate behaviors without a need for intensity biases. How nonpheromonal attractants are processed by the general olfactory system remains largely unknown. In the moth Manduca sexta, we studied this with a set of innately preferred host plant odors and other, neutral odors. Electroantennogram recordings showed that, as a population, olfactory receptor neurons (ORNs) did not respond with greater intensity to host plant odors, and further local field potential recordings showed that no specific amplification of signals induced by host plant odors occurred between the first olfactory center and the second. Moreover, when odorants were mutually diluted to elicit equally intense output from the ORNs, moths were able to learn to associate all tested odorants equally well with food reward. Together, these results suggest that, although nonpheromonal host plant odors activate broadly distributed responses, they may be linked to attractive behaviors mainly through specific wiring in the brain. PMID:22362866

  15. Odor memory stability after reinnervation of the olfactory bulb.

    Directory of Open Access Journals (Sweden)

    Eduardo Blanco-Hernández

    Full Text Available The olfactory system, particularly the olfactory epithelium, presents a unique opportunity to study the regenerative capabilities of the brain, because of its ability to recover after damage. In this study, we ablated olfactory sensory neurons with methimazole and followed the anatomical and functional recovery of circuits expressing genetic markers for I7 and M72 receptors (M72-IRES-tau-LacZ and I7-IRES-tau-GFP. Our results show that 45 days after methimazole-induced lesion, axonal projections to the bulb of M72 and I7 populations are largely reestablished. Furthermore, regenerated glomeruli are re-formed within the same areas as those of control, unexposed mice. This anatomical regeneration correlates with functional recovery of a previously learned odorant-discrimination task, dependent on the cognate ligands for M72 and I7. Following regeneration, mice also recover innate responsiveness to TMT and urine. Our findings show that regeneration of neuronal circuits in the olfactory system can be achieved with remarkable precision and underscore the importance of glomerular organization to evoke memory traces stored in the brain.

  16. Refining the dual olfactory hypothesis: pheromone reward and odour experience.

    Science.gov (United States)

    Martínez-García, Fernando; Martínez-Ricós, Joana; Agustín-Pavón, Carmen; Martínez-Hernández, Jose; Novejarque, Amparo; Lanuza, Enrique

    2009-06-25

    In rodents, sexual advertisement and gender recognition are mostly (if not exclusively) mediated by chemosignals. Specifically, there is ample evidence indicating that female mice are 'innately' attracted by male sexual pheromones that have critical non-volatile components and are detected by the vomeronasal organ. These pheromones can only get access to the vomeronasal organ by active pumping mechanisms that require close contact with the source of the stimulus (e.g. urine marks) during chemoinvestigation. We have hypothesised that male sexual pheromones are rewarding to female mice. Indeed, male-soiled bedding can be used as a reinforcer to induce conditioned place preference, provided contact with the bedding is allowed. The neural mechanisms of pheromone reward seem, however, different from those employed by other natural reinforcers, such as the sweetness or postingestive effects of sucrose. In contrast to vomeronasal-detected male sexual pheromones, male-derived olfactory stimuli (volatiles) are not intrinsically attractive to female mice. However, after repeated exposure to male-soiled bedding, intact female mice develop an acquired preference for male odours. On the contrary, in females whose accessory olfactory bulbs have been lesioned, exposure to male-soiled bedding induces aversion to male odorants. These considerations, together with data on the different properties of olfactory and vomeronasal receptors, lead us to make a proposal for the complementary roles that the olfactory and vomeronasal systems play in intersexual attraction and in other forms of intra- or inter-species communication.

  17. Olfactory Memory Impairment in Neurodegenerative Diseases

    OpenAIRE

    Bahuleyan, Biju; Singh, Satendra

    2012-01-01

    Olfactory disorders are noted in a majority of neurodegenerative diseases, but they are often misjudged and are rarely rated in the clinical setting. Severe changes in the olfactory tests are observed in Parkinson's disease. Olfactory deficits are an early feature in Alzheimer's disease and they worsen with the disease progression. Alterations in the olfactory function are also noted after severe head injuries, temporal lobe epilepsy, multiple sclerosis, and migraine. The purpose of the prese...

  18. Role of olfactory bulb serotonin in olfactory learning in the greater short-nosed fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae).

    Science.gov (United States)

    Ganesh, Ambigapathy; Bogdanowicz, Wieslaw; Haupt, Moritz; Marimuthu, Ganapathy; Rajan, Koilmani Emmanuvel

    2010-09-17

    The role of olfactory bulb (OB) serotonin [5-hydroxytryptamine (5-HT)] in olfactory learning and memory was tested in the greater short-nosed fruit bat, Cynopterus sphinx (family Pteropodidae). Graded concentrations (25, 40, and 60microg) of 5,7-dihydroxytryptamine (5,7-DHT) or saline were injected into the OB of bats one day before training to the novel odor. In a behavioral test, 5,7-DHT (60microg) injected bats made significantly fewer feeding attempts and bouts when compared to saline-injected bats during learning and in the memory test. Subsequent biochemical analysis showed that 5-HT level was effectively depleted in the OB of 5,7-DHT injected bats. To test odor-induced 5-HT mediated changes in 5-HT receptors and second messenger cascade in the OB, we examined the expression of 5-HT receptors and mitogen-activated protein kinase (MAPK)/Erk cascade after training to the novel odor. We found that odor stimulation up-regulated the expression of 5-HT(1A) receptor, Erk1 and Creb1 mRNA, and phosphorylation of ERK1 and CREB1. Odor stimulation failed to induce expression in 5-HT-depleted bats, which is similar to control bats and significantly low compared to saline-treated bats. Together these data revealed that the level of 5-HT in the OB may regulate olfactory learning and memory in C. sphinx through Erk and CREB.

  19. Cytological organization of the alpha component of the anterior olfactory nucleus and olfactory limbus

    Directory of Open Access Journals (Sweden)

    Jorge A Larriva-Sahd

    2012-06-01

    Full Text Available This study describes the microscopic organization of a wedge-shaped area at the intersection of the main and accessory olfactory bulbs, or olfactory limbus , and an additional component of the anterior olfactory nucleus or alpha accessory olfactory bulb that lies underneath of the accessory olfactory bulb. The olfactory limbus consists of a modified bulbar cortex bounded anteriorly by the main olfactory bulb and posteriorly by the accessory olfactory bulb. In Nissl-stained specimens the olfactory limbus differs from the main olfactory bulb by a progressive, antero-posterior decrease in thickness or absence of the external plexiform, mitral/tufted cell, and granule cell layers. On cytoarchitectual grounds the olfactory limbus is divided from rostral to caudal into three distinct components: a stripe of glomerular-free cortex or preolfactory area, a second or necklace glomerular area, and a wedge-shaped or interstitial area crowned by the so-called modified glomeruli that appear to belong to the anterior accessory olfactory bulb. The strategic location and interactions with the main and accessory olfactory bulbs, together with the previously noted functional and connectional evidence, suggest that the olfactory limbus may be related to both sensory modalities. The alpha component of the anterior olfactory nucleus, a slender cellular cluster (i.e., 650 x 150 µm paralleling the base of the accessory olfactory bulb, contains two neuron types: a pyramidal-like neuron and an interneuron. Dendrites of pyramidal-like cells organize into a single bundle that ascends avoiding the accessory olfactory bulb to resolve in a trigone bounded by the edge of the olfactory limbus, the accessory olfactory bulb and the dorsal part of the anterior olfactory nucleus. Utrastructurally, the neuropil of the alpha component contains three types of synaptic terminals; one of them immunoreactive to the enzyme glutamate decarboxylase, isoform 67.

  20. Predicting the response of olfactory sensory neurons to odor mixtures from single odor response

    Science.gov (United States)

    Marasco, Addolorata; de Paris, Alessandro; Migliore, Michele

    2016-04-01

    The response of olfactory receptor neurons to odor mixtures is not well understood. Here, using experimental constraints, we investigate the mathematical structure of the odor response space and its consequences. The analysis suggests that the odor response space is 3-dimensional, and predicts that the dose-response curve of an odor receptor can be obtained, in most cases, from three primary components with specific properties. This opens the way to an objective procedure to obtain specific olfactory receptor responses by manipulating mixtures in a mathematically predictable manner. This result is general and applies, independently of the number of odor components, to any olfactory sensory neuron type with a response curve that can be represented as a sigmoidal function of the odor concentration.

  1. Sniffing and Oxytocin: Effects on Olfactory Memories.

    Science.gov (United States)

    Stoop, Ron

    2016-05-04

    In this issue of Neuron, Oettl et al. (2016) show how oxytocin can boost processing of olfactory information in female rats by a top-downregulation from the anterior olfactory nucleus onto the main olfactory bulb. As a result, interactions with juvenile conspecifics receive more attention and are longer memorized. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Effect of irradiation on olfactory function

    International Nuclear Information System (INIS)

    Aiba, Tsunemasa; Sugimoto, Midori; Matsuda, Yasuaki; Sugiura, Yoshikazu; Nakai, Yoshiaki; Nakajima, Toshifumi

    1990-01-01

    The effects of therapeutic irradiation on olfactory function were investigated in 20 patients who received radiation therapy because of a malignant tumor of the nose or paranasal sinuses. The standard olfaction test with a T and T olfactometer and an intravenous olfaction test were given before the radiation therapy, during the period of radiation therapy and 1, 3, 6 and 12 months or more later. Five patients whose olfactory epithelium was outside the radiation field showed no damage to olfactory function. The olfactory function of the other 15 patients whose olfactory epithelium had been exposed to radiation was not obviously changed or damaged at the time of radiation therapy. However, 6 months after irradiation, some patients showed a decline in olfactory function, and after 12 months, 4 of 7 patients showed severe damage to olfactory function. These results suggest that a therapeutic dose of irradiation will not cause severe damage to the olfactory function during the period of radiation therapy, but could cause delayed olfactory disorders in some patients after a few years. These olfactory disorders might be caused by damage to or degeneration of the olfactory epithelium or olfactory nerve. (author)

  3. Traumatic brain injury and olfactory deficits

    DEFF Research Database (Denmark)

    Fortin, Audrey; Lefebvre, Mathilde Beaulieu; Ptito, Maurice

    2010-01-01

    . Between 40-44% of the patients showing olfactory impairments were not aware of their deficit. CONCLUSIONS: Since a significant proportion of the patients showing olfactory impairments were not aware of their deficit, it is recommended than clinicians systematically evaluate olfactory functions using...

  4. Serotonin increases synaptic activity in olfactory bulb glomeruli.

    Science.gov (United States)

    Brill, Julia; Shao, Zuoyi; Puche, Adam C; Wachowiak, Matt; Shipley, Michael T

    2016-03-01

    Serotoninergic fibers densely innervate olfactory bulb glomeruli, the first sites of synaptic integration in the olfactory system. Acting through 5HT2A receptors, serotonin (5HT) directly excites external tufted cells (ETCs), key excitatory glomerular neurons, and depolarizes some mitral cells (MCs), the olfactory bulb's main output neurons. We further investigated 5HT action on MCs and determined its effects on the two major classes of glomerular interneurons: GABAergic/dopaminergic short axon cells (SACs) and GABAergic periglomerular cells (PGCs). In SACs, 5HT evoked a depolarizing current mediated by 5HT2C receptors but did not significantly impact spike rate. 5HT had no measurable direct effect in PGCs. Serotonin increased spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) in PGCs and SACs. Increased sEPSCs were mediated by 5HT2A receptors, suggesting that they are primarily due to enhanced excitatory drive from ETCs. Increased sIPSCs resulted from elevated excitatory drive onto GABAergic interneurons and augmented GABA release from SACs. Serotonin-mediated GABA release from SACs was action potential independent and significantly increased miniature IPSC frequency in glomerular neurons. When focally applied to a glomerulus, 5HT increased MC spontaneous firing greater than twofold but did not increase olfactory nerve-evoked responses. Taken together, 5HT modulates glomerular network activity in several ways: 1) it increases ETC-mediated feed-forward excitation onto MCs, SACs, and PGCs; 2) it increases inhibition of glomerular interneurons; 3) it directly triggers action potential-independent GABA release from SACs; and 4) these network actions increase spontaneous MC firing without enhancing responses to suprathreshold sensory input. This may enhance MC sensitivity while maintaining dynamic range. Copyright © 2016 the American Physiological Society.

  5. Comparative Geometrical Analysis of Leucine-Rich Repeat Structures in the Nod-Like and Toll-Like Receptors in Vertebrate Innate Immunity

    Directory of Open Access Journals (Sweden)

    Norio Matsushima

    2015-08-01

    Full Text Available The NOD-like receptors (NLRs and Toll-like receptors (TLRs are pattern recognition receptors that are involved in the innate, pathogen pattern recognition system. The TLR and NLR receptors contain leucine-rich repeats (LRRs that are responsible for ligand interactions. In LRRs short β-strands stack parallel and then the LRRs form a super helical arrangement of repeating structural units (called a coil of solenoids. The structures of the LRR domains of NLRC4, NLRP1, and NLRX1 in NLRs and of TLR1-5, TLR6, TLR8, TLR9 in TLRs have been determined. Here we report nine geometrical parameters that characterize the LRR domains; these include four helical parameters from HELFIT analysis. These nine parameters characterize well the LRR structures in NLRs and TLRs; the LRRs of NLR adopts a right-handed helix. In contrast, the TLR LRRs adopt either a left-handed helix or are nearly flat; RP105 and CD14 also adopt a left-handed helix. This geometrical analysis subdivides TLRs into four groups consisting of TLR3/TLR8/TLR9, TLR1/TLR2/TRR6, TLR4, and TLR5; these correspond to the phylogenetic tree based on amino acid sequences. In the TLRs an ascending lateral surface that consists of loops connecting the β-strand at the C-terminal side is involved in protein, protein/ligand interactions, but not the descending lateral surface on the opposite side.

  6. Imaging the vertebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Tay, Keng Yeow; U-King-Im, Jean Marie; Trivedi, Rikin A.; Higgins, Nicholas J.; Cross, Justin J.; Antoun, Nagui M. [Addenbrooke' s Hospital and University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Davies, John R.; Weissberg, Peter L. [Addenbrooke' s Hospital and University of Cambridge, Division of Cardiovascular Medicine, Cambridge (United Kingdom); Gillard, Jonathan H. [Addenbrooke' s Hospital and University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Addenbrooke' s Hospitald, University Department of Radiology, Cambridge (United Kingdom)

    2005-07-01

    Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed. (orig.)

  7. Imaging the vertebral artery

    International Nuclear Information System (INIS)

    Tay, Keng Yeow; U-King-Im, Jean Marie; Trivedi, Rikin A.; Higgins, Nicholas J.; Cross, Justin J.; Antoun, Nagui M.; Davies, John R.; Weissberg, Peter L.; Gillard, Jonathan H.

    2005-01-01

    Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed. (orig.)

  8. Early survival factor deprivation in the olfactory epithelium enhances activity-dependent survival

    Directory of Open Access Journals (Sweden)

    Adrien eFrançois

    2013-12-01

    Full Text Available The neuronal olfactory epithelium undergoes permanent renewal because of environmental aggression. This renewal is partly regulated by factors modulating the level of neuronal apoptosis. Among them, we had previously characterized endothelin as neuroprotective. In this study, we explored the effect of cell survival factor deprivation in the olfactory epithelium by intranasal delivery of endothelin receptors antagonists to rat pups. This treatment induced an overall increase of apoptosis in the olfactory epithelium. The responses to odorants recorded by electroolfactogram were decreased in treated animal, a result consistent with a loss of olfactory sensory neurons (OSNs. However, the treated animal performed better in an olfactory orientation test based on maternal odor compared to non-treated littermates. This improved performance could be due to activity-dependent neuronal survival of OSNs in the context of increased apoptosis level. In order to demonstrate it, we odorized pups with octanal, a known ligand for the rI7 olfactory receptor (Olr226. We quantified the number of OSN expressing rI7 by RT-qPCR and whole mount in situ hybridization. While this number was reduced by the survival factor removal treatment, this reduction was abolished by the presence of its ligand. This improved survival was optimal for low concentration of odorant and was specific for rI7-expressing OSNs. Meanwhile, the number of rI7-expressing OSNs was not affected by the odorization in non-treated littermates; showing that the activity-dependant survival of OSNs did not affect the OSN population during the 10 days of odorization in control conditions. Overall, our study shows that when apoptosis is promoted in the olfactory mucosa, the activity-dependent neuronal plasticity allows faster tuning of the olfactory sensory neuron population towards detection of environmental odorants.

  9. Gene Expression Profiles of Main Olfactory Epithelium in Adenylyl Cyclase 3 Knockout Mice

    Directory of Open Access Journals (Sweden)

    Zhenshan Wang

    2015-11-01

    Full Text Available Adenylyl Cyclase 3 (AC3 plays an important role in the olfactory sensation-signaling pathway in mice. AC3 deficiency leads to defects in olfaction. However, it is still unknown whether AC3 deficiency affects gene expression or olfactory signal transduction pathways within the main olfactory epithelium (MOE. In this study, gene microarrays were used to screen differentially expressed genes in MOE from AC3 knockout (AC3−/− and wild-type (AC3+/+ mice. The differentially expressed genes identified were subjected to bioinformatic analysis and verified by qRT-PCR. Gene expression in the MOE from AC3−/− mice was significantly altered, compared to AC3+/+ mice. Of the 41266 gene probes, 3379 had greater than 2-fold fold change in expression levels between AC3−/− and AC3+/+ mice, accounting for 8% of the total gene probes. Of these genes, 1391 were up regulated, and 1988 were down regulated, including 425 olfactory receptor genes, 99 genes that are specifically expressed in the immature olfactory neurons, 305 genes that are specifically expressed in the mature olfactory neurons, and 155 genes that are involved in epigenetic regulation. Quantitative RT-PCR verification of the differentially expressed epigenetic regulation related genes, olfactory receptors, ion transporter related genes, neuron development and differentiation related genes, lipid metabolism and membrane protein transport etc. related genes showed that P75NTR, Hinfp, Gadd45b, and Tet3 were significantly up-regulated, while Olfr370, Olfr1414, Olfr1208, Golf, Faim2, Tsg101, Mapk10, Actl6b, H2BE, ATF5, Kirrrel2, OMP, Drd2 etc. were significantly down-regulated. In summary, AC3 may play a role in proximal olfactory signaling and play a role in the regulation of differentially expressed genes in mouse MOE.

  10. Olfactory memory impairment in neurodegenerative diseases.

    Science.gov (United States)

    Bahuleyan, Biju; Singh, Satendra

    2012-10-01

    Olfactory disorders are noted in a majority of neurodegenerative diseases, but they are often misjudged and are rarely rated in the clinical setting. Severe changes in the olfactory tests are observed in Parkinson's disease. Olfactory deficits are an early feature in Alzheimer's disease and they worsen with the disease progression. Alterations in the olfactory function are also noted after severe head injuries, temporal lobe epilepsy, multiple sclerosis, and migraine. The purpose of the present review was to discuss the available scientific knowledge on the olfactory memory and to relate its impairment with neurodegenerative diseases.

  11. Loss of CO2 sensing by the olfactory system of CNGA3 knockout mice

    Directory of Open Access Journals (Sweden)

    Jinlong HAN, Minmin LUO

    2010-12-01

    Full Text Available Atmospheric CO2 can signal the presence of food, predators or environmental stress and trigger stereotypical behaviors in both vertebrates and invertebrates. Recent studies have shown that the necklace olfactory system in mice sensitively detects CO2 in the air. Olfactory CO2 neurons are believed to rely on cyclic guanosine monophosphate (cGMP as the key second messenger; however, the specific ion channel underlying CO­2 responses remains unclear. Here we show that CO2-evoked neuronal and behavioral responses require cyclic nucleotide-gated (CNG channels consisting of the CNGA3 subunit. Through Ca2+-imaging, we found that CO2-triggered Ca2+ influx was abolished in necklace olfactory sensory neurons (OSNs of CNGA3-knockout mice. Olfactory detection tests using a Go/No-go paradigm showed that these knockout mice failed to detect 0.5% CO2. Thus, sensitive detection of atmospheric CO2 depends on the function of CNG channels consisting of the CNGA3 subunit in necklace OSNs. These data support the important role of the necklace olfactory system in CO2 sensing and extend our understanding of the signal transduction pathway mediating CO2 detection in mammals [Current Zoology 56 (6: 793–799, 2010].

  12. An Olfactory Cinema: Smelling Perfume

    Directory of Open Access Journals (Sweden)

    Jiaying Sim

    2014-09-01

    Full Text Available While technological improvements from the era of silent movies to that of sound cinema have altered and continued to affect audience’s cinematic experiences, the question is not so much how technology has increased possibility of a sensory response to cinema, rather, it is one that exposes how such technological changes only underscore the participation of our senses and the body in one’s experience of watching film, highlighting the inherently sensorial nature of the cinematic experience. This paper aims to address the above question through an olfactory cinema, by close analysis of Perfume: The Story of a Murderer (2006 by Tom Tykwer. What is an olfactory cinema, and how can such an approach better our understanding of sensorial aspects found within a cinema that ostensibly favours audio-visual senses? What can we benefit from an olfactory cinema? Perhaps, it is through an olfactory cinema that one may begin to embrace the sensual quality of cinema that has been overshadowed by the naturalized ways of experiencing films solely with our eyes and ears, so much so that we desensitize ourselves to the role our senses play in cinematic experiences altogether

  13. Olfactory memory traces in Drosophila.

    Science.gov (United States)

    Berry, Jacob; Krause, William C; Davis, Ronald L

    2008-01-01

    In Drosophila, the fruit fly, coincident exposure to an odor and an aversive electric shock can produce robust behavioral memory. This behavioral memory is thought to be regulated by cellular memory traces within the central nervous system of the fly. These molecular, physiological, or structural changes in neurons, induced by pairing odor and shock, regulate behavior by altering the neurons' response to the learned environment. Recently, novel in vivo functional imaging techniques have allowed researchers to observe cellular memory traces in intact animals. These investigations have revealed interesting temporal and spatial dynamics of cellular memory traces. First, a short-term cellular memory trace was discovered that exists in the antennal lobe, an early site of olfactory processing. This trace represents the recruitment of new synaptic activity into the odor representation and forms for only a short period of time just after training. Second, an intermediate-term cellular memory trace was found in the dorsal paired medial neuron, a neuron thought to play a role in stabilizing olfactory memories. Finally, a long-term protein synthesis-dependent cellular memory trace was discovered in the mushroom bodies, a structure long implicated in olfactory learning and memory. Therefore, it appears that aversive olfactory associations are encoded by multiple cellular memory traces that occur in different regions of the brain with different temporal domains.

  14. Olfactory training in patients with Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Antje Haehner

    Full Text Available OBJECTIVE: Decrease of olfactory function in Parkinson's disease (PD is a well-investigated fact. Studies indicate that pharmacological treatment of PD fails to restore olfactory function in PD patients. The aim of this investigation was whether patients with PD would benefit from "training" with odors in terms of an improvement of their general olfactory function. It has been hypothesized that olfactory training should produce both an improved sensitivity towards the odors used in the training process and an overall increase of olfactory function. METHODS: We recruited 70 subjects with PD and olfactory loss into this single-center, prospective, controlled non-blinded study. Thirty-five patients were assigned to the olfactory training group and 35 subjects to the control group (no training. Olfactory training was performed over a period of 12 weeks while patients exposed themselves twice daily to four odors (phenyl ethyl alcohol: rose, eucalyptol: eucalyptus, citronellal: lemon, and eugenol: cloves. Olfactory testing was performed before and after training using the "Sniffin' Sticks" (thresholds for phenyl ethyl alcohol, tests for odor discrimination, and odor identification in addition to threshold tests for the odors used in the training process. RESULTS: Compared to baseline, trained PD patients experienced a significant increase in their olfactory function, which was observed for the Sniffin' Sticks test score and for thresholds for the odors used in the training process. Olfactory function was unchanged in PD patients who did not perform olfactory training. CONCLUSION: The present results indicate that olfactory training may increase olfactory sensitivity in PD patients.

  15. Identification and Characterization of Pheromone Receptors and Interplay between Receptors and Pheromone Binding Proteins in the Diamondback Moth, Plutella xyllostella

    OpenAIRE

    Sun, Mengjing; Liu, Yang; Walker, William B.; Liu, Chengcheng; Lin, Kejian; Gu, Shaohua; Zhang, Yongjun; Zhou, Jingjiang; Wang, Guirong

    2013-01-01

    Moths depend on olfactory cues such as sex pheromones to find and recognize mating partners. Pheromone receptors (PRs) and Pheromone binding proteins (PBPs) are thought to be associated with olfactory signal transduction of pheromonal compounds in peripheral olfactory reception. Here six candidate pheromone receptor genes in the diamondback moth, Plutella xyllostella were identified and cloned. All of the six candidate PR genes display male-biased expression, which is a typical characteristic...

  16. Metal X-ray microanalysis in the olfactory system of rainbow trout exposed to low level of copper

    International Nuclear Information System (INIS)

    Julliard, A.K.; Astic, L.; Saucier, D.

    1995-01-01

    It has recently been shown that a chronic copper exposure induces specific degeneration of olfactory receptor cells in rainbow trout; however, the exact mechanism of action of the metal is not yet known. Using X-ray microanalysis in transmission electron microscopy, we have studied the distribution of metal in the olfactory system of fish exposed for 15,30 and 60 days to 20 μg/l of copper. This was done in order to determine if it was accumulated in receptor cells and transported into the central nervous system via the olfactory nerve. No copper accumulation was detected either in the olfactory epithelium, in the olfactory nerve or in the olfactory bulb. The heavy metal was exclusively found within melanosomes of melanophores located in the lamina propria. After 60 days of exposure, the copper content in melanosomes was about two-fold higher than that in controls. As far as some morphological recovery took place in the olfactory organ during the metal exposure, which lets us suppose that some detoxication mechanism occurs, it could be suggested that metanophores might be somehow involved in such a mechanism. (authors). 57 refs., 15 figs

  17. Olfactory dysfunction, olfactory bulb pathology and urban air pollution

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Osnaya, Norma; González-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderon, Rafael; Herritt, Lou; Brooks, Diane; Keefe, Sheyla; Palacios-Moreno, Juan; Villarreal-Calderon, Rodolfo; Torres-Jardón, Ricardo; Medina-Cortina, Humberto; Delgado-Chávez, Ricardo; Aiello-Mora, Mario; Maronpot, Robert R.; Doty, Richard L

    2010-01-01

    Mexico City (MC) residents are exposed to severe air pollution and exhibit olfactory bulb inflammation. We compared the olfactory function of individuals living under conditions of extreme air pollution to that of controls from a relatively clean environment and explore associations between olfaction scores, apolipoprotein E (APOE) status, and pollution exposure. The olfactory bulbs (OBs) of 35 MC and 9 controls 20.8 ± 8.5 y were assessed by light and electron microscopy. The University of Pennsylvania Smell Identification Test (UPSIT) was administered to 62 MC / 25 controls 21.2 ±2.7 y. MC subjects had significantly lower UPSIT scores: 34.24 ± 0.42 versus controls 35.76 ± 0.40, p=0.03. Olfaction deficits were present in 35.5% MC and 12% of controls. MC APOE ε 4 carriers failed 2.4 ± 0.54 items in the 10-item smell identification scale from the UPSIT related to Alzheimer's disease, while APOE 2/3 and 3/3 subjects failed 1.36 ± 0.16 items, p = 0.01. MC residents exhibited OB endothelial hyperplasia, neuronal accumulation of particles (2/35), and immunoreactivity to beta amyloid βA42 (29/35) and/or α-synuclein (4/35) in neurons, glial cells and/or blood vessels. Ultrafine particles were present in OBs endothelial cytoplasm and basement membranes. Control OBs were unremarkable. Air pollution exposure is associated with olfactory dysfunction and OB pathology, APOE 4 may confer greater susceptibility to such abnormalities, and ultrafine particles could play a key role in the OB pathology. This study contributes to our understanding of the influences of air pollution on olfaction and its potential contribution to neurodegeneration. PMID:19297138

  18. When the Nose Doesn’t Know: Canine Olfactory Function Associated With Health, Management, and Potential Links to Microbiota

    OpenAIRE

    Eileen K. Jenkins; Mallory T. DeChant; Erin B. Perry

    2018-01-01

    The impact of health, management, and microbiota on olfactory function in canines has not been examined in review. The most important characteristic of the detection canine is its sense of smell. Olfactory receptors are primarily located on the ethmoturbinates of the nasal cavity. The vomeronasal organ is an additional site of odor detection that detects chemical signals that stimulate behavioral and/or physiological changes. Recent advances in the genetics of olfaction suggest that genetic c...

  19. Olfactory transduction pathways in the Senegalese sole Solea senegalensis.

    Science.gov (United States)

    Velez, Z; Hubbard, P C; Barata, E N; Canário, A V M

    2013-09-01

    This study tested whether differences in sensitivity between the upper and lower olfactory epithelia of Solea senegalensis are associated with different odorant receptors and transduction pathways, using the electro-olfactogram. Receptor mechanisms were assessed by cross-adaptation with amino acids (L-cysteine, L-phenylalanine and 1-methyl-L-tryptophan) and bile acids (taurocholic acid and cholic acid). This suggested that relatively specific receptors exist for 1-methyl-L-tryptophan and L-phenylalanine (food-related odorants) in the lower epithelium, and for taurocholic acid (conspecific-derived odorant) in the upper. Inhibition by U73122 [a phospholipase C (PLC) inhibitor] suggested that olfactory responses to amino acids were mediated mostly, but not entirely, by PLC-mediated transduction (IC50 ; 15-55 nM), whereas bile acid responses were mediated by both PLC and adenylate cyclase-cyclic adenosine monophosphate (AC-cAMP) (using SQ-22536; an AC inhibitor). Simultaneous application of both drugs rarely inhibited responses completely, suggesting possible involvement of non-PLC and non-AC mediated mechanisms. For aromatic amino acids and bile acids, there were differences in the contribution of each transduction pathway (PLC, AC and non-PLC and non-AC) between the two epithelia. These results suggest that differences in sensitivity of the two epithelia are associated with differences in odorant receptors and transduction mechanisms. © 2013 The Fisheries Society of the British Isles.

  20. The Mouse Solitary Odorant Receptor Gene Promoters as Models for the Study of Odorant Receptor Gene Choice.

    Directory of Open Access Journals (Sweden)

    Andrea Degl'Innocenti

    Full Text Available In vertebrates, several anatomical regions located within the nasal cavity mediate olfaction. Among these, the main olfactory epithelium detects most conventional odorants. Olfactory sensory neurons, provided with cilia exposed to the air, detect volatile chemicals via an extremely large family of seven-transmembrane chemoreceptors named odorant receptors. Their genes are expressed in a monogenic and monoallelic fashion: a single allele of a single odorant receptor gene is transcribed in a given mature neuron, through a still uncharacterized molecular mechanism known as odorant receptor gene choice.Odorant receptor genes are typically arranged in genomic clusters, but a few are isolated (we call them solitary from the others within a region broader than 1 Mb upstream and downstream with respect to their transcript's coordinates. The study of clustered genes is problematic, because of redundancy and ambiguities in their regulatory elements: we propose to use the solitary genes as simplified models to understand odorant receptor gene choice.Here we define number and identity of the solitary genes in the mouse genome (C57BL/6J, and assess the conservation of the solitary status in some mammalian orthologs. Furthermore, we locate their putative promoters, predict their homeodomain binding sites (commonly present in the promoters of odorant receptor genes and compare candidate promoter sequences with those of wild-caught mice. We also provide expression data from histological sections.In the mouse genome there are eight intact solitary genes: Olfr19 (M12, Olfr49, Olfr266, Olfr267, Olfr370, Olfr371, Olfr466, Olfr1402; five are conserved as solitary in rat. These genes are all expressed in the main olfactory epithelium of three-day-old mice. The C57BL/6J candidate promoter of Olfr370 has considerably varied compared to its wild-type counterpart. Within the putative promoter for Olfr266 a homeodomain binding site is predicted. As a whole, our findings

  1. Cigarette Smoke-Induced Cell Death Causes Persistent Olfactory Dysfunction in Aged Mice

    Directory of Open Access Journals (Sweden)

    Rumi Ueha

    2018-06-01

    Full Text Available Introduction: Exposure to cigarette smoke is a cause of olfactory dysfunction. We previously reported that in young mice, cigarette smoke damaged olfactory progenitors and decreased mature olfactory receptor neurons (ORNs, then, mature ORNs gradually recovered after smoking cessation. However, in aged populations, the target cells in ORNs by cigarette smoke, the underlying molecular mechanisms by which cigarette smoke impairs the regenerative ORNs, and the degree of ORN regeneration after smoking cessation remain unclear.Objectives: To explore the effects of cigarette smoke on the ORN cell system using an aged mouse model of smoking, and to investigate the extent to which smoke-induced damage to ORNs recovers following cessation of exposure to cigarette smoke in aged mice.Methods: We intranasally administered a cigarette smoke solution (CSS to 16-month-old male mice over 24 days, then examined ORN existence, cell survival, changes of inflammatory cytokines in the olfactory epithelium (OE, and olfaction using histological analyses, gene analyses and olfactory habituation/dishabituation tests.Results: CSS administration reduced the number of mature ORNs in the OE and induced olfactory dysfunction. These changes coincided with an increase in the number of apoptotic cells and Tumor necrosis factor (TNF expression and a decrease in Il6 expression. Notably, the reduction in mature ORNs did not recover even on day 28 after cessation of treatment with CSS, resulting in persistent olfactory dysfunction.Conclusion: In aged mice, by increasing ORN death, CSS exposure could eventually overwhelm the regenerative capacity of the OE, resulting in continued reduction in the number of mature ORNs and olfactory dysfunction.

  2. Molecular determinants of odorant receptor function in insects

    Indian Academy of Sciences (India)

    2014-07-20

    Jul 20, 2014 ... other host-odor responsive receptors from vector insect spe- cies would .... those that mediate host-seeking behaviour in insect disease vectors and ... receptors are transmitted and processed via olfactory circuits. (Vosshall ...

  3. Odor Preference Learning and Memory Modify GluA1 Phosphorylation and GluA1 Distribution in the Neonate Rat Olfactory Bulb: Testing the AMPA Receptor Hypothesis in an Appetitive Learning Model

    Science.gov (United States)

    Cui, Wen; Darby-King, Andrea; Grimes, Matthew T.; Howland, John G.; Wang, Yu Tian; McLean, John H.; Harley, Carolyn W.

    2011-01-01

    An increase in synaptic AMPA receptors is hypothesized to mediate learning and memory. AMPA receptor increases have been reported in aversive learning models, although it is not clear if they are seen with memory maintenance. Here we examine AMPA receptor changes in a cAMP/PKA/CREB-dependent appetitive learning model: odor preference learning in…

  4. Postnatal odorant exposure induces peripheral olfactory plasticity at the cellular level.

    Science.gov (United States)

    Cadiou, Hervé; Aoudé, Imad; Tazir, Bassim; Molinas, Adrien; Fenech, Claire; Meunier, Nicolas; Grosmaitre, Xavier

    2014-04-02

    Mammalian olfactory sensory neurons (OSNs) form the primary elements of the olfactory system. Inserted in the olfactory mucosa lining of the nasal cavity, they are exposed to the environment and their lifespan is brief. Several reports say that OSNs are regularly regenerated during the entire life and that odorant environment affects the olfactory epithelium. However, little is known about the impact of the odorant environment on OSNs at the cellular level and more precisely in the context of early postnatal olfactory exposure. Here we exposed MOR23-green fluorescent protein (GFP) and M71-GFP mice to lyral or acetophenone, ligands for MOR23 or M71, respectively. Daily postnatal exposure to lyral induces plasticity in the population of OSNs expressing MOR23. Their density decreases after odorant exposure, whereas the amount of MOR23 mRNA and protein remain stable in the whole epithelium. Meanwhile, quantitative PCR indicates that each MOR23 neuron has higher levels of olfactory receptor transcripts and also expresses more CNGA2 and phosphodiesterase 1C, fundamental olfactory transduction pathway proteins. Transcript levels return to baseline after 4 weeks recovery. Patch-clamp recordings reveal that exposed MOR23 neurons respond to lyral with higher sensitivity and broader dynamic range while the responses' kinetics were faster. These effects are specific to the odorant-receptor pair lyral-MOR23: there was no effect of acetophenone on MOR23 neurons and no effect of acetophenone and lyral on the M71 population. Together, our results clearly demonstrate that OSNs undergo specific anatomical, molecular, and functional adaptation when chronically exposed to odorants in the early stage of life.

  5. Effects of radiotherapy on olfactory function

    International Nuclear Information System (INIS)

    Hoelscher, Tobias; Seibt, Annedore; Appold, Steffen; Doerr, Wolfgang; Herrmann, Thomas; Huettenbrink, Karl-Bernd; Hummel, Thomas

    2005-01-01

    Background and Purpose: Changes in olfactory function have been reported in patients receiving significant doses of radiation to the olfactory epithelium. Aim of this study was to investigate severity and time course of changes in olfactory function in patients irradiated for tumours of the head and neck region. Material and Methods: Forty-four patients receiving radiotherapy (RT) for tumours in the area of the head and neck participated (16 women, 28 men; age 11-81 y; mean 55 y). Olfactory function was measured before and bi-weekly during RT for 6 weeks. A subgroup (25 patients) was followed for 12 months. Patients were divided into two groups according to the dose to the olfactory epithelium. Twenty-two patients ('OLF group') had radiation doses to the olfactory epithelium between 23.7 and 79.5 Gy (median 62.2 Gy). In the 22 patients of the 'non-OLF group' the dose applied to the olfactory epithelium was significantly lower (2.9-11.1 Gy, median 5.9 Gy). Total tumour dose (30-76.8 Gy), age, sex distribution, and baseline chemosensory function were not significantly different between groups. Testing was performed for odour identification, odour discrimination, and olfactory thresholds. Results: Odour discrimination, but not odour identification or odour threshold, was significantly decreased 2-6 weeks after begin of therapy in the OLF group. In addition, a significant effect of the radiation dose was observed for odour discrimination. More than 6 months after therapy, OLF group patients had significantly lower odour identification scores compared to the non-OLF group. Conclusion: As indicated through the non-significant change of olfactory thresholds, the olfactory epithelium is relatively resistant against effects of radiation. It is hypothesized that RT has additional effects on the olfactory bulb/orbitofrontal cortex responsible for the observed changes of suprathreshold olfactory function

  6. Role of Centrifugal Projections to the Olfactory Bulb in Olfactory Processing

    Science.gov (United States)

    Kiselycznyk, Carly L.; Zhang, Steven; Linster, Christine

    2006-01-01

    While there is evidence that feedback projections from cortical and neuromodulatory structures to the olfactory bulb are crucial for maintaining the oscillatory dynamics of olfactory bulb processing, it is not clear how changes in dynamics are related to odor perception. Using electrical lesions of the olfactory peduncle, sparing output from the…

  7. SLEEP AND OLFACTORY CORTICAL PLASTICITY

    Directory of Open Access Journals (Sweden)

    Dylan eBarnes

    2014-04-01

    Full Text Available In many systems, sleep plays a vital role in memory consolidation and synaptic homeostasis. These processes together help store information of biological significance and reset synaptic circuits to facilitate acquisition of information in the future. In this review, we describe recent evidence of sleep-dependent changes in olfactory system structure and function which contribute to odor memory and perception. During slow-wave sleep, the piriform cortex becomes hypo-responsive to odor stimulation and instead displays sharp-wave activity similar to that observed within the hippocampal formation. Furthermore, the functional connectivity between the piriform cortex and other cortical and limbic regions is enhanced during slow-wave sleep compared to waking. This combination of conditions may allow odor memory consolidation to occur during a state of reduced external interference and facilitate association of odor memories with stored hedonic and contextual cues. Evidence consistent with sleep-dependent odor replay within olfactory cortical circuits is presented. These data suggest that both the strength and precision of odor memories is sleep-dependent. The work further emphasizes the critical role of synaptic plasticity and memory in not only odor memory but also basic odor perception. The work also suggests a possible link between sleep disturbances that are frequently co-morbid with a wide range of pathologies including Alzheimer’s disease, schizophrenia and depression and the known olfactory impairments associated with those disorders.

  8. Head segmentation in vertebrates

    OpenAIRE

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Her...

  9. Distribution of the orphan nuclear receptor Nurr1 in medaka (Oryzias latipes): cues to the definition of homologous cell groups in the vertebrate brain.

    Science.gov (United States)

    Kapsimali, M; Bourrat, F; Vernier, P

    2001-03-12

    The orphan nuclear receptor Nurr1 has been extensively studied in mammals and shown to contribute to the differentiation of several cell phenotypes in the nervous and endocrine systems. In this study, the gene homologous to the mammalian Nurr1 (NR4A2) was isolated in the teleost fish medaka (Oryzias latipes), and the distribution of its transcripts was analyzed within brains of embryos and adults. Nurr1 has a widespread distribution in the medaka brain. Large amounts of Nurr1 transcripts were found in the intermediate nucleus of the ventral telencephalon, preoptic magnocellular nucleus, ventral habenula, nucleus of the periventricular posterior tuberculum, and nuclei of glossopharyngeal and vagus nerves. To search for homologous cell groups between teleost fish and tetrapods brains, the co-localization of Nurr1 and tyrosine hydroxylase (TH) transcripts was analyzed. Neither Nurr1 nor TH expression was detected in the ventral midbrain, but both transcripts were present in the periventricular nucleus of the posterior tuberculum. This observation supports the hypothesis that this nucleus is homologous to dopaminergic mesencephalic nuclei of mammals. The presence of Nurr1 in the preoptic magnocellular nucleus of medaka and paraventricular hypothalamic nucleus of mammals reinforces the hypothesis of homology between these areas. TH and Nurr1 transcripts are also co-localized, among others, in the nucleus of the paraventricular organ and nucleus of the vagus nerve. This work suggests that the differentiating role of Nurr1 in the central nervous system is conserved in gnathostomes. Copyright 2001 Wiley-Liss, Inc.

  10. Short-term memory in olfactory network dynamics

    Science.gov (United States)

    Stopfer, Mark; Laurent, Gilles

    1999-12-01

    Neural assemblies in a number of animal species display self-organized, synchronized oscillations in response to sensory stimuli in a variety of brain areas.. In the olfactory system of insects, odour-evoked oscillatory synchronization of antennal lobe projection neurons (PNs) is superimposed on slower and stimulus-specific temporal activity patterns. Hence, each odour activates a specific and dynamic projection neuron assembly whose evolution during a stimulus is locked to the oscillation clock. Here we examine, using locusts, the changes in population dynamics of projection-neuron assemblies over repeated odour stimulations, as would occur when an animal first encounters and then repeatedly samples an odour for identification or localization. We find that the responses of these assemblies rapidly decrease in intensity, while they show a marked increase in spike time precision and inter-neuronal oscillatory coherence. Once established, this enhanced precision in the representation endures for several minutes. This change is stimulus-specific, and depends on events within the antennal lobe circuits, independent of olfactory receptor adaptation: it may thus constitute a form of sensory memory. Our results suggest that this progressive change in olfactory network dynamics serves to converge, over repeated odour samplings, on a more precise and readily classifiable odour representation, using relational information contained across neural assemblies.

  11. Not all sharks are "swimming noses": variation in olfactory bulb size in cartilaginous fishes.

    Science.gov (United States)

    Yopak, Kara E; Lisney, Thomas J; Collin, Shaun P

    2015-03-01

    Olfaction is a universal modality by which all animals sample chemical stimuli from their environment. In cartilaginous fishes, olfaction is critical for various survival tasks including localizing prey, avoiding predators, and chemosensory communication with conspecifics. Little is known, however, about interspecific variation in olfactory capability in these fishes, or whether the relative importance of olfaction in relation to other sensory systems varies with regard to ecological factors, such as habitat and lifestyle. In this study, we have addressed these questions by directly examining interspecific variation in the size of the olfactory bulbs (OB), the region of the brain that receives the primary sensory projections from the olfactory nerve, in 58 species of cartilaginous fishes. Relative OB size was compared among species occupying different ecological niches. Our results show that the OBs maintain a substantial level of allometric independence from the rest of the brain across cartilaginous fishes and that OB size is highly variable among species. These findings are supported by phylogenetic generalized least-squares models, which show that this variability is correlated with ecological niche, particularly habitat. The relatively largest OBs were found in pelagic-coastal/oceanic sharks, especially migratory species such as Carcharodon carcharias and Galeocerdo cuvier. Deep-sea species also possess large OBs, suggesting a greater reliance on olfaction in habitats where vision may be compromised. In contrast, the smallest OBs were found in the majority of reef-associated species, including sharks from the families Carcharhinidae and Hemiscyllidae and dasyatid batoids. These results suggest that there is great variability in the degree to which these fishes rely on olfactory cues. The OBs have been widely used as a neuroanatomical proxy for olfactory capability in vertebrates, and we speculate that differences in olfactory capabilities may be the result of

  12. Vertebral osteomyelitis without disc involvement

    Energy Technology Data Exchange (ETDEWEB)

    Kamani, I.; Syed, I.; Saifuddin, A. E-mail: asaifuddin@aol.com; Green, R.; MacSweeney, F

    2004-10-01

    Vertebral osteomyelitis is most commonly due to pyogenic or granulomatous infection and typically results in the combined involvement of the intervertebral disc and adjacent vertebral bodies. Non-infective causes include the related conditions of chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. Occasionally, these conditions may present purely within the vertebral body, resulting in various combinations of vertebral marrow oedema and sclerosis, destructive lesions of the vertebral body and pathological vertebral collapse, thus mimicking neoplastic disease. This review illustrates the imaging features of vertebral osteomyelitis without disc involvement, with emphasis on magnetic resonance imaging (MRI) findings.

  13. Olfactory impairment in the rotenone model of Parkinson's disease is associated with bulbar dopaminergic D2 activity after REM sleep deprivation

    Directory of Open Access Journals (Sweden)

    Laís Soares Rodrigues

    2014-12-01

    Full Text Available Olfactory and rapid eye movement (REM sleep deficits are commonly found in untreated subjects with a recent diagnosis of Parkinson's disease (PD. Besides different studies reported declines in olfactory performances during a short period of sleep deprivation. Mechanisms underlying these clinical manifestations are poorly understood although the impairment in the dopamine (DA neurotransmission in the olfactory bulb and in the nigrostriatal pathway may have important roles in olfactory as well as in REM sleep disturbances. Therefore, we have led to the hypothesis that a modulation of the dopaminergic D2 receptors in the olfactory bulb could provide a more comprehensive understanding of the olfactory deficits in PD and after a short period of REM sleep deprivation (REMSD. We decided to investigate the olfactory, neurochemical and histological alterations generated by the administration of piribedil (a selective D2 agonist or raclopride (a selective D2 antagonist, within the glomerular layer of the olfactory bulb, in rats submitted to intranigral rotenone and REMSD. Our findings provided a remarkable evidence of the occurrence of a negative correlation (r = - 0.52, P = 0.04 between the number of periglomerular TH-ir neurons and the bulbar levels of DA in the rotenone, but not sham groups. A significant positive correlation (r = 0.34, P = 0.03 was observed between nigral DA and olfactory discrimination index (DI, for the sham groups, indicating that increased DA levels in the substantia nigra pars compacta (SNpc are associated to enhanced olfactory discrimination performance. Also, increased levels in bulbar and striatal DA induced by piribedil in the rotenone control and rotenone REMSD groups were consistent with reduced amounts of DI. The present evidence reinforce that DA produced by periglomerular neurons, and particularly the bulbar dopaminergic D2 receptors, are essential participants in the olfactory discrimination processes, as well as SNpc

  14. Predicting the response of olfactory sensory neurons to odor mixtures from single odor response

    OpenAIRE

    Marasco, Addolorata; De Paris, Alessandro; Migliore, Michele

    2016-01-01

    The response of olfactory receptor neurons to odor mixtures is not well understood. Here, using experimental constraints, we investigate the mathematical structure of the odor response space and its consequences. The analysis suggests that the odor response space is 3-dimensional, and predicts that the dose-response curve of an odor receptor can be obtained, in most cases, from three primary components with specific properties. This opens the way to an objective procedure to obtain specific o...

  15. The Feasibility of Gelatin-Based Retronasal Stimuli to Assess Olfactory Perception

    Directory of Open Access Journals (Sweden)

    Daniel Shepherd

    2015-10-01

    Full Text Available Links between some psychological disorders and olfactory deficits are well documented, and screening tests have been developed to exploit these associations. Odors can take one of two routes to the olfactory receptors in the nasal epithelium, the orthonasal or retronasal route. This article discusses the potential use of the retronasal route to assess olfaction using gelatin-based stimuli delivered orally. Using a relatively new psychophysical method, the Single-Interval Adjustment Matrix task, we estimated vanillin thresholds for five healthy participants sampling small vanillin flavored gels. Our data demonstrate the feasibility of using solid-state gustatory stimuli to assess retronasal perception.

  16. Duration and specificity of olfactory nonassociative memory.

    Science.gov (United States)

    Freedman, Kaitlin G; Radhakrishna, Sreya; Escanilla, Olga; Linster, Christiane

    2013-05-01

    Olfactory habituation is a simple form of nonassociative memory in which responsiveness to stable but behaviorally nonsignificant stimuli is decreased. Olfactory habituation has recently become a paradigm widely used to probe the neural substrate underlying olfactory perception and memory. This simple behavioral paradigm has been used successfully used to probe many aspects of olfactory processing, and it has recently become clear that the neural processes underlying olfactory habituation can depend on the task parameters used. We here further investigate memory specificity and duration using 2 variations in task parameters: the number of habituation trials and the time delay between habituation and cross-habituation testing. We find that memory specificity increases with the number of habituation trials but decreases with time after the last habituation trial.

  17. Discrimination of bile acids by the rainbow trout olfactory system: Evidence as potential pheromone

    Directory of Open Access Journals (Sweden)

    PERCILIA C GIAQUINTO

    2008-01-01

    Full Text Available Electro-olfactogram recording was used to determine whether the olfactory epithelium of adult rainbow trout is specifically sensitive to bile acids, some of which have been hypothesized to function as pheromones. Of 38 bile acids that had been pre-screened for olfactory activity, 6 were selected. The rainbow trout-specific bile acids, taurocholic acid (TCA, and taurolithocholic acid 3-sulfate (TLS were the most potent compounds tested. TLS had a distinctive dose-response curve. Cross-adaptation experiments demonstrated that sensitivity to bile acids is attributable to at least 3 independent classes of olfactory receptor sites. Our data suggest that bile acids are discriminated by olfaction in rainbow trout, supporting the possibility that these compounds function as pheromones

  18. Sensory memory for odors is encoded in spontaneous correlated activity between olfactory glomeruli.

    Science.gov (United States)

    Galán, Roberto F; Weidert, Marcel; Menzel, Randolf; Herz, Andreas V M; Galizia, C Giovanni

    2006-01-01

    Sensory memory is a short-lived persistence of a sensory stimulus in the nervous system, such as iconic memory in the visual system. However, little is known about the mechanisms underlying olfactory sensory memory. We have therefore analyzed the effect of odor stimuli on the first odor-processing network in the honeybee brain, the antennal lobe, which corresponds to the vertebrate olfactory bulb. We stained output neurons with a calcium-sensitive dye and measured across-glomerular patterns of spontaneous activity before and after a stimulus. Such a single-odor presentation changed the relative timing of spontaneous activity across glomeruli in accordance with Hebb's theory of learning. Moreover, during the first few minutes after odor presentation, correlations between the spontaneous activity fluctuations suffice to reconstruct the stimulus. As spontaneous activity is ubiquitous in the brain, modifiable fluctuations could provide an ideal substrate for Hebbian reverberations and sensory memory in other neural systems.

  19. Disruption of Aedes aegypti olfactory system development through chitosan/siRNA nanoparticle targeting of semaphorin-1a.

    Directory of Open Access Journals (Sweden)

    Keshava Mysore

    Full Text Available Despite the devastating impact of mosquito-borne illnesses on human health, surprisingly little is known about mosquito developmental biology, including development of the olfactory system, a tissue of vector importance. Analysis of mosquito olfactory developmental genetics has been hindered by a lack of means to target specific genes during the development of this sensory system. In this investigation, chitosan/siRNA nanoparticles were used to target semaphorin-1a (sema1a during olfactory system development in the dengue and yellow fever vector mosquito Aedes aegypti. Immunohistochemical analyses and anterograde tracing of antennal sensory neurons, which were used to track the progression of olfactory development in this species, revealed antennal lobe defects in sema1a knockdown fourth instar larvae. These findings, which correlated with a larval odorant tracking behavioral phenotype, identified previously unreported roles for Sema1a in the developing insect larval olfactory system. Analysis of sema1a knockdown pupae also revealed a number of olfactory phenotypes, including olfactory receptor neuron targeting and projection neuron defects coincident with a collapse in the structure and shape of the antennal lobe and individual glomeruli. This study, which is to our knowledge the first functional genetic analysis of insect olfactory development outside of D. melanogaster, identified critical roles for Sema1a during Ae. aegypti larval and pupal olfactory development and advocates the use of chitosan/siRNA nanoparticles as an effective means of targeting genes during post-embryonic Ae. aegypti development. Use of siRNA nanoparticle methodology to understand sensory developmental genetics in mosquitoes will provide insight into the evolutionary conservation and divergence of key developmental genes which could be exploited in the development of both common and species-specific means for intervention.

  20. Cholinergic innervation of the zebrafish olfactory bulb.

    Science.gov (United States)

    Edwards, Jeffrey G; Greig, Ann; Sakata, Yoko; Elkin, Dimitry; Michel, William C

    2007-10-20

    A number of fish species receive forebrain cholinergic input but two recent reports failed to find evidence of cholinergic cell bodies or fibers in the olfactory bulbs (OBs) of zebrafish. In the current study we sought to confirm these findings by examining the OBs of adult zebrafish for choline acetyltransferase (ChAT) immunoreactivity. We observed a diffuse network of varicose ChAT-positive fibers associated with the nervus terminalis ganglion innervating the mitral cell/glomerular layer (MC/GL). The highest density of these fibers occurred in the anterior region of the bulb. The cellular targets of this cholinergic input were identified by exposing isolated OBs to acetylcholine receptor (AChR) agonists in the presence of agmatine (AGB), a cationic probe that permeates some active ion channels. Nicotine (50 microM) significantly increased the activity-dependent labeling of mitral cells and juxtaglomerular cells but not of tyrosine hydroxlase-positive dopaminergic neurons (TH(+) cells) compared to control preparations. The nAChR antagonist mecamylamine, an alpha7-nAChR subunit-specific antagonist, calcium-free artificial cerebrospinal fluid, or a cocktail of ionotropic glutamate receptor (iGluR) antagonists each blocked nicotine-stimulated labeling, suggesting that AGB does not enter the labeled neurons through activated nAChRs but rather through activated iGluRs following ACh-stimulated glutamate release. Deafferentation of OBs did not eliminate nicotine-stimulated labeling, suggesting that cholinergic input is primarily acting on bulbar neurons. These findings confirm the presence of a functioning cholinergic system in the zebrafish OB.

  1. A Closer Look at Acid-Base Olfactory Titrations

    Science.gov (United States)

    Neppel, Kerry; Oliver-Hoyo, Maria T.; Queen, Connie; Reed, Nicole

    2005-01-01

    Olfactory titrations using raw onions and eugenol as acid-base indicators are reported. An in-depth investigation on olfactory titrations is presented to include requirements for potential olfactory indicators and protocols for using garlic, onions, and vanillin as acid-base olfactory indicators are tested.

  2. The role of main olfactory and vomeronasal systems in animal ...

    African Journals Online (AJOL)

    In many terrestrial tetrapod, olfactory sensory communication is mediated by two anatomically and functionally distinct sensory systems; the main olfactory system and vomeronasal system (accessory olfactory system). Recent anatomical studies of the central pathways of the olfactory and vomeronasal systems showed that ...

  3. Differential interactions of sex pheromone and plant odour in the olfactory pathway of a male moth.

    Directory of Open Access Journals (Sweden)

    Nina Deisig

    Full Text Available Most animals rely on olfaction to find sexual partners, food or a habitat. The olfactory system faces the challenge of extracting meaningful information from a noisy odorous environment. In most moth species, males respond to sex pheromone emitted by females in an environment with abundant plant volatiles. Plant odours could either facilitate the localization of females (females calling on host plants, mask the female pheromone or they could be neutral without any effect on the pheromone. Here we studied how mixtures of a behaviourally-attractive floral odour, heptanal, and the sex pheromone are encoded at different levels of the olfactory pathway in males of the noctuid moth Agrotis ipsilon. In addition, we asked how interactions between the two odorants change as a function of the males' mating status. We investigated mixture detection in both the pheromone-specific and in the general odorant pathway. We used a recordings from individual sensilla to study responses of olfactory receptor neurons, b in vivo calcium imaging with a bath-applied dye to characterize the global input response in the primary olfactory centre, the antennal lobe and c intracellular recordings of antennal lobe output neurons, projection neurons, in virgin and newly-mated males. Our results show that heptanal reduces pheromone sensitivity at the peripheral and central olfactory level independently of the mating status. Contrarily, heptanal-responding olfactory receptor neurons are not influenced by pheromone in a mixture, although some post-mating modulation occurs at the input of the sexually isomorphic ordinary glomeruli, where general odours are processed within the antennal lobe. The results are discussed in the context of mate localization.

  4. Interglomerular Connectivity within the Canonical and GC-D/Necklace Olfactory Subsystems.

    Directory of Open Access Journals (Sweden)

    Cedric R Uytingco

    Full Text Available The mammalian main olfactory system contains several subsystems that differ not only in the receptors they express and the glomerular targets they innervate within the main olfactory bulb (MOB, but also in the strategies they use to process odor information. The canonical main olfactory system employs a combinatorial coding strategy that represents odorant identity as a pattern of glomerular activity. By contrast, the "GC-D/necklace" olfactory subsystem-formed by olfactory sensory neurons expressing the receptor guanylyl cyclase GC-D and their target necklace glomeruli (NGs encircling the caudal MOB-is critical for the detection of a small number of semiochemicals that promote the acquisition of food preferences. The formation of these socially-transmitted food preferences requires the animal to integrate information about two types of olfactory stimuli: these specialized social chemosignals and the food odors themselves. However, the neural mechanisms with which the GC-D/necklace subsystem processes this information are unclear. We used stimulus-induced increases in intrinsic fluorescence signals to map functional circuitry associated with NGs and canonical glomeruli (CGs in the MOB. As expected, CG-associated activity spread laterally through both the glomerular and external plexiform layers associated with activated glomeruli. Activation of CGs or NGs resulted in activity spread between the two types of glomeruli; there was no evidence of preferential connectivity between individual necklace glomeruli. These results support previous anatomical findings that suggest the canonical and GC-D/necklace subsystems are functionally connected and may integrate general odor and semiochemical information in the MOB.

  5. An olfactory subsystem that detects carbon disulfide and mediates food-related social learning.

    Science.gov (United States)

    Munger, Steven D; Leinders-Zufall, Trese; McDougall, Lisa M; Cockerham, Renee E; Schmid, Andreas; Wandernoth, Petra; Wennemuth, Gunther; Biel, Martin; Zufall, Frank; Kelliher, Kevin R

    2010-08-24

    Olfactory signals influence social interactions in a variety of species. In mammals, pheromones and other social cues can promote mating or aggression behaviors; can communicate information about social hierarchies, genetic identity and health status; and can contribute to associative learning. However, the molecular, cellular, and neural mechanisms underlying many olfactory-mediated social interactions remain poorly understood. Here, we report that a specialized olfactory subsystem that includes olfactory sensory neurons (OSNs) expressing the receptor guanylyl cyclase GC-D, the cyclic nucleotide-gated channel subunit CNGA3, and the carbonic anhydrase isoform CAII (GC-D(+) OSNs) is required for the acquisition of socially transmitted food preferences (STFPs) in mice. Using electrophysiological recordings from gene-targeted mice, we show that GC-D(+) OSNs are highly sensitive to the volatile semiochemical carbon disulfide (CS(2)), a component of rodent breath and a known social signal mediating the acquisition of STFPs. Olfactory responses to CS(2) are drastically reduced in mice lacking GC-D, CNGA3, or CAII. Disruption of this sensory transduction cascade also results in a failure to acquire STFPs from either live or surrogate demonstrator mice or to exhibit hippocampal correlates of STFP retrieval. Our findings indicate that GC-D(+) OSNs detect chemosignals that facilitate food-related social interactions. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. Identification of a novel Gnao-mediated alternate olfactory signaling pathway in murine OSNs

    Directory of Open Access Journals (Sweden)

    Paul eScholz

    2016-03-01

    Full Text Available It is generally agreed that in olfactory sensory neurons (OSNs, the binding of odorant molecules to their specific olfactory receptor (OR triggers a cAMP-dependent signaling cascade, activating cyclic-nucleotide gated (CNG channels. However, considerable controversy dating back more than 20 years has surrounded the question of whether alternate signaling plays a role in mammalian olfactory transduction. In this study, we demonstrate a specific alternate signaling pathway in Olfr73-expressing OSNs. Methylisoeugenol (MIEG and at least one other known weak Olfr73 agonist (Raspberry Ketone trigger a signaling cascade independent from the canonical pathway, leading to the depolarization of the cell. Interestingly, this pathway is mediated by Gnao activation, leading to Cl- efflux; however, the activation of adenylyl cyclase III (ACIII, the recruitment of Ca2+ from extra-or intracellular stores, and phosphatidylinositol 3-kinase-dependent signaling (PI signaling are not involved. Furthermore, we demonstrated that our newly identified pathway coexists with the canonical olfactory cAMP pathway in the same OSN and can be triggered by the same OR in a ligand-selective manner. We suggest that this pathway might reflect a mechanism for odor recognition predominantly used in early developmental stages before olfactory cAMP signaling is fully developed. Taken together, our findings support the existence of at least one odor-induced alternate signal transduction pathway in native OSNs mediated by Olfr73 in a ligand-selective manner.

  7. Honey Bee Allatostatins Target Galanin/Somatostatin-Like Receptors and Modulate Learning: A Conserved Function?

    Directory of Open Access Journals (Sweden)

    Elodie Urlacher

    Full Text Available Sequencing of the honeybee genome revealed many neuropeptides and putative neuropeptide receptors, yet functional characterization of these peptidic systems is scarce. In this study, we focus on allatostatins, which were first identified as inhibitors of juvenile hormone synthesis, but whose role in the adult honey bee (Apis mellifera brain remains to be determined. We characterize the bee allatostatin system, represented by two families: allatostatin A (Apime-ASTA and its receptor (Apime-ASTA-R; and C-type allatostatins (Apime-ASTC and Apime-ASTCC and their common receptor (Apime-ASTC-R. Apime-ASTA-R and Apime-ASTC-R are the receptors in bees most closely related to vertebrate galanin and somatostatin receptors, respectively. We examine the functional properties of the two honeybee receptors and show that they are transcriptionally expressed in the adult brain, including in brain centers known to be important for learning and memory processes. Thus we investigated the effects of exogenously applied allatostatins on appetitive olfactory learning in the bee. Our results show that allatostatins modulate learning in this insect, and provide important insights into the evolution of somatostatin/allatostatin signaling.

  8. Primary olfactory projections and the nervus terminalis in the African lungfish: implications for the phylogeny of cranial nerves.

    Science.gov (United States)

    von Bartheld, C S; Claas, B; Münz, H; Meyer, D L

    1988-08-01

    Primary olfactory and central projections of the nervus terminalis were investigated by injections of horseradish peroxidase into the olfactory epithelium in the African lungfish. In addition, gonadotropin-releasing hormone (GnRH) immunoreactivity of the nervus terminalis system was investigated. The primary olfactory projections are restricted to the olfactory bulb located at the rostral pole of the telencephalon; they do not extend into caudal parts of the telencephalon. A vomeronasal nerve and an accessory olfactory bulb could not be identified. The nervus terminalis courses through the dorsomedial telencephalon. Major targets include the nucleus of the anterior commissure and the nucleus praeopticus pars superior. some fibers cross to the contralateral side. A few fibers reach the diencephalon and mesencephalon. No label is present in the "posterior root of the nervus terminalis" (= "Pinkus's nerve" or "nervus praeopticus"). GnRH immunoreactivity is lacking in the "anterior root of the nervus terminalis," whereas it is abundant in nervus praeopticus (Pinkus's nerve). These findings may suggest that the nervus terminalis system originally consisted of two distinct cranial nerves, which have fused-in evolution-in most vertebrates. Theories of cranial nerve phylogeny are discussed in the light of the assumed "binerval origin" of the nervus terminalis system.

  9. Endogenous GABA and Glutamate Finely Tune the Bursting of Olfactory Bulb External Tufted Cells

    Science.gov (United States)

    Hayar, Abdallah; Ennis, Matthew

    2008-01-01

    In rat olfactory bulb slices, external tufted (ET) cells spontaneously generate spike bursts. Although ET cell bursting is intrinsically generated, its strength and precise timing may be regulated by synaptic input. We tested this hypothesis by analyzing whether the burst properties are modulated by activation of ionotropic γ-aminobutyric acid (GABA) and glutamate receptors. Blocking GABAA receptors increased—whereas blocking ionotropic glutamate receptors decreased—the number of spikes/burst without changing the interburst frequency. The GABAA agonist (isoguvacine, 10 μM) completely inhibited bursting or reduced the number of spikes/burst, suggesting a shunting effect. These findings indicate that the properties of ET cell spontaneous bursting are differentially controlled by GABAergic and glutamatergic fast synaptic transmission. We suggest that ET cell excitatory and inhibitory inputs may be encoded as a change in the pattern of spike bursting in ET cells, which together with mitral/tufted cells constitute the output circuit of the olfactory bulb. PMID:17567771

  10. Imaging of vertebral trauma

    International Nuclear Information System (INIS)

    Daffner, R.H.

    1999-01-01

    This translation of the toolbook published in the 'US-ART' series, offers invaluable help to medical radiologists in the diagnostic imaging and evaluation of complex vertebral traumas which are on the rise, inter alia due to increasingly dangerous leisure sports. (orig./CB) [de

  11. Olfactory bulb as an alternative in neurotransplantation

    Directory of Open Access Journals (Sweden)

    Руслан Романович Новиков

    2015-05-01

    Full Text Available The article examines the ethical and legal aspects of transplantation of embryonic neural tissue, structure of the rat olfactory bulb. It is given substantiation for its use as a possible alternative version of the embryonic neural tissue at damage in the cerebral hemispheres in the experiment.Materials and methods. Detailed description of the fault model of the cerebral hemispheres of the brain of rats, olfactory bulb biopsy procedure, cultivation of olfactory bulb suspension and fetal neural tissue, comparison of the functional aspects of transplantation of the olfactory bulb and the embryonic neural tissue.Results. The obtained data are similar to structure of olfactory bulb and fetal tissues during culturing. Recovery in the motor areas varies by the time factor and less intense in the group of the olfactory bulb and the group without tissue transplantation.Conclusions. Comparative analysis of the effectiveness of transplantation of embryonic neural tissue and olfactory bulb in the injured brain allows us to speak about the positive results of these groups to the difference in the duration of the recovery process

  12. Imaging the olfactory tract (Cranial Nerve no.1)

    International Nuclear Information System (INIS)

    Duprez, Thierry P.; Rombaux, Philippe

    2010-01-01

    This review paper browses pros and cons of the different radiological modalities for imaging the olfactory tract and highlights the potential benefits and limitation of more recent advances in MR and CT technology. A systematic pictorial overview of pathological conditions affecting olfactory sense is given. Techniques for collecting quantitative data on olfactory bulb volume and on olfactory sulcus depth are described. At last, insights into functional imaging of olfactory sense are shown.

  13. Evolution of neural crest and placodes: amphioxus as a model for the ancestral vertebrate?

    Science.gov (United States)

    Holland, L. Z.; Holland, N. D.

    2001-01-01

    Recent studies of protochordates (ascidian tunicates and amphioxus) have given insights into possible ancestors of 2 of the characteristic features of the vertebrate head: neural crest and placodes. The neural crest probably evolved from cells on either side of the neural plate-epidermis boundary in a protochordate ancestral to the vertebrates. In amphioxus, homologues of several vertebrate neural crest marker genes (BMP2/4, Pax3/7, Msx, Dll and Snail) are expressed at the edges of the neural plate and/or adjacent nonneural ectoderm. Some of these markers are also similarly expressed in tunicates. In protochordates, however, these cells, unlike vertebrate neural crest, neither migrate as individuals through embryonic tissues nor differentiate into a wide spectrum of cell types. Therefore, while the protochordate ancestor of the vertebrates probably had the beginnings of a genetic programme for neural crest formation, this programme was augmented in the earliest vertebrates to attain definitive neural crest. Clear homologues of vertebrate placodes are lacking in protochordates. However, both amphioxus and tunicates have ectodermal sensory cells. In tunicates these are all primary neurons, sending axons to the central nervous system, while in amphioxus, the ectodermal sensory cells include both primary neurons and secondary neurons lacking axons. Comparisons of developmental gene expression suggest that the anterior ectoderm in amphioxus may be homologous to the vertebrate olfactory placode, the only vertebrate placode with primary, not secondary, neurons. Similarly, biochemical, morphological and gene expression data suggest that amphioxus and tunicates also have homologues of the adenohypophysis, one of the few vertebrate structures derived from nonneurogenic placodes. In contrast, the origin of the other vertebrate placodes is very uncertain.

  14. Timberol® Inhibits TAAR5-Mediated Responses to Trimethylamine and Influences the Olfactory Threshold in Humans.

    Directory of Open Access Journals (Sweden)

    Ivonne Wallrabenstein

    Full Text Available In mice, trace amine-associated receptors (TAARs are interspersed in the olfactory epithelium and constitute a chemosensory subsystem that is highly specific for detecting volatile amines. Humans possess six putative functional TAAR genes. Human TAAR5 (hTAAR5 is highly expressed in the olfactory mucosa and was shown to be specifically activated by trimethylamine. In this study, we were challenged to uncover an effective blocker substance for trimethylamine-induced hTAAR5 activation. To monitor blocking effects, we recombinantly expressed hTAAR5 and employed a commonly used Cre-luciferase reporter gene assay. Among all tested potential blocker substances, Timberol®, an amber-woody fragrance, is able to inhibit the trimethylamine-induced hTAAR5 activation up to 96%. Moreover, human psychophysical data showed that the presence of Timberol® increases the olfactory detection threshold for the characteristic fishy odor of trimethylamine by almost one order of magnitude. In conclusion, our results show that among tested receptors Timberol® is a specific and potent antagonist for the hTAAR5-mediated response to trimethylamine in a heterologous system. Furthermore, our data concerning the observed shift of the olfactory detection threshold in vivo implicate that hTAAR5 or other receptors that may be inhibited by Timberol® could be involved in the high affinity olfactory perception of trimethylamine in humans.

  15. Olfactory Functioning in First-Episode Psychosis.

    Science.gov (United States)

    Kamath, Vidyulata; Lasutschinkow, Patricia; Ishizuka, Koko; Sawa, Akira

    2018-04-06

    Though olfactory deficits are well-documented in schizophrenia, fewer studies have examined olfactory performance profiles across the psychosis spectrum. The current study examined odor identification, discrimination, and detection threshold performance in first-episode psychosis (FEP) patients diagnosed with schizophrenia, schizoaffective disorder, bipolar disorder with psychotic features, major depression with psychotic features, and other psychotic conditions. FEP patients (n = 97) and healthy adults (n = 98) completed birhinal assessments of odor identification, discrimination, and detection threshold sensitivity for lyral and citralva. Participants also completed measures of anticipatory pleasure, anhedonia, and empathy. Differences in olfactory performances were assessed between FEP patients and controls and within FEP subgroups. Sex-stratified post hoc analyses were employed for a complete analysis of sex differences. Relationships between self-report measures and olfactory scores were also examined. Individuals with psychosis had poorer scores across all olfactory measures when compared to the control group. Within the psychosis cohort, patients with schizophrenia-associated psychosis had poorer odor identification, discrimination, and citralva detection threshold scores relative to controls. In schizophrenia patients, greater olfactory disturbance was associated with increased negative symptomatology, greater self-reported anhedonia, and lower self-reported anticipatory pleasure. Patients with mood-associated psychosis performed comparable to controls though men and women in this cohort showed differential olfactory profiles. These findings indicate that olfactory deficits extend beyond measures of odor identification in FEP with greater deficits observed in schizophrenia-related subgroups of psychosis. Studies examining whether greater olfactory dysfunction confers greater risk for developing schizophrenia relative to other forms of psychosis are

  16. Management of osteoporotic vertebral fractures

    OpenAIRE

    Dionyssiotis, Yannis

    2010-01-01

    Yannis DionyssiotisRhodes General Hospital, Rhodes, GreeceAbstract: Osteoporotic vertebral fractures are associated with considerable reduction of quality of life, morbidity, and mortality. The management of patients with vertebral fractures should include treatment for osteoporosis and measures to reduce pain and improve mobility. This article provides information for management and rehabilitation of vertebral fractures based on clinical experience and literature.Keywords: vertebral fracture...

  17. Clinical diagnosis and treatment of olfactory meningioma

    International Nuclear Information System (INIS)

    Li Xiangdong; Wang Zhong; Zhang Shiming; Zhu Fengqing; Zhou Dai; Hui Guozhen

    2005-01-01

    Objective: To analyze the clinical diagnosis and treatment of olfactory meningioma. Methods: In this group 17 olfactory meningiomas were operated, and the clinical presentations and the surgery results were obtained. Results: The symptoms of psychiatrical disorder, visual disturbances and eclipse at presentation was higher. In 16 cases the grade of resection was Simpson II, 1 case Simpson III, most of the cases had a good recovery. Conclusion: Attention should be paid to the early symptom at presentation such as psychiatrical disorder to obtain an early diagnosis. Microsurgery is useful in the treatment of olfactory meningioma. (authors)

  18. Olfactory nerve transport of macromolecular drugs to the brain. A problem in olfactory impaired patients

    International Nuclear Information System (INIS)

    Shiga, Hideaki; Yamamoto, Junpei; Miwa, Takaki

    2012-01-01

    Nasal administration of macromolecular drugs (including peptides and nanoparticles) has the potential to enable drug delivery system beyond the blood brain barrier (BBB) via olfactory nerve transport. Basic research on drug deliver systems to the brain via nasal administration has been well reported. Insulin-like growth factor-I (IGF-I) is associated with the development and growth of the central nervous system. Clinical application of IGF-I with nasal administration is intended to enable drug delivery to brain through the BBB. Uptake of IGF-I in the olfactory bulb and central nervous system increased according to the dosage of nasally administered IGF-I in normal ICR mice, however IGF-I uptake in the trigeminal nerve remained unchanged. Olfactory nerve transport is important for the delivery of nasally administered IGF-I to the brain in vivo. Because a safe olfactory nerve tracer has not been clinically available, olfactory nerve transport has not been well studied in humans. Nasal thallium-201 ( 201 Tl) administration has been safely used to assess the direct pathway to the brain via the nose in healthy volunteers with a normal olfactory threshold. 201 Tl olfactory nerve transport has recently been shown to decrease in patients with hyposmia. The olfactory nerve transport function in patients with olfactory disorders will be determined using 201 Tl olfacto-scintigraphy for the exclusion of candidates in a clinical trial to assess the usefulness of nasal administration of IGF-I. (author)

  19. Predicting vertebral bone strength by vertebral static histomorphometry

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Ebbesen, Ebbe Nils; Mosekilde, Lis

    2002-01-01

    of the entire vertebral bodies (L-2) were used for histomorphometry. The other iliac crest biopsies and the L-3 were destructively tested by compression. High correlation was found between BV/TV or Tb.Sp and vertebral bone strength (absolute value of r = 0.86 in both cases). Addition of Tb.Th significantly....... No gender-related differences were found in any of the relationships. Neither static histomorphometry nor biomechanical testing of iliac crest bone biopsies is a good predictor of vertebral bone strength.......The study investigates the relationship between static histomorphometry and bone strength of human lumbar vertebral bone. The ability of vertebral histomorphometry to predict vertebral bone strength was compared with that of vertebral densitometry, and also with histomorphometry and bone strength...

  20. 17β-estradiol enhances memory duration in the main olfactory bulb in CD-1 mice.

    Science.gov (United States)

    Dillon, T Samuel; Fox, Laura C; Han, Crystal; Linster, Christiane

    2013-12-01

    Rodents rely heavily on odor detection, discrimination, and memory to locate food, find mates, care for pups, and avoid predators. Estrogens have been shown to increase memory retention in rodents performing spatial memory and object placement tasks. Here we evaluate the extent to which 17β-estradiol modulates memory formation and duration in the olfactory system. Adult CD-1 mice were gonadectomized and given either systemic 17β-estradiol replacement, local 17β-estradiol in the main olfactory bulb, or no replacement. Before performing the behavioral task the mice were given saline or PHTPP (an estrogen receptor β [ER-β] antagonist) via bilateral infusion into the main olfactory bulb. As the beta-type estrogen receptor (ER-β) is more abundant than the alpha-type estrogen receptor in the murine main olfactory bulb, the current study focuses on 17β-estradiol and its interactions with ERβ. Habituation, a simple, nonassociative learning task in which an animal is exposed to the same odor over successive presentations, was used to evaluate the animals' ability to detect odors and form an olfactory memory. To evaluate memory duration, we added a final trial of intertrial interval time (30 or 60 min) in which we presented the habituated odor. Neither surgical nor drug manipulation affected the ability of mice to detect or habituate to an odor. After habituation, gonadectomized 17β-estradiol-treated mice retained memory of an odor for 30 min, whereas non-estradiol-treated, 17β-estradiol+ERβ antagonist (PHTPP), and untreated male mice did not remember an odor 30 min after habituation. The results show that both systemic and local bulbar infusions of 17β-estradiol enhance odor memory duration in mice.

  1. Olfactory cuing of autobiographical memory.

    Science.gov (United States)

    Rubin, D C; Groth, E; Goldsmith, D J

    1984-01-01

    In Experiment 1, subjects were presented with either the odors or the names of 15 common objects. In Experiment 2, subjects were presented with either the odors, photographs, or names of 16 common objects. All subjects were asked to describe an autobiographical memory evoked by each cue, to date each memory, and to rate each memory on vividness, pleasantness, and the number of times that the memory had been thought of and talked about prior to the experiment. Compared with memories evoked by photographs or names, memories evoked by odors were reported to be thought of and talked about less often prior to the experiment and were more likely to be reported as never having been thought of or talked about prior to the experiment. No other effects were consistently found, though there was a suggestion that odors might evoke more pleasant and emotional memories than other types of cues. The relation of these results to the folklore concerning olfactory cuing is discussed.

  2. Methods to measure olfactory behavior in mice.

    Science.gov (United States)

    Zou, Junhui; Wang, Wenbin; Pan, Yung-Wei; Lu, Song; Xia, Zhengui

    2015-02-02

    Mice rely on the sense of olfaction to detect food sources, recognize social and mating partners, and avoid predators. Many behaviors of mice, including learning and memory, social interaction, fear, and anxiety are closely associated with their function of olfaction, and behavior tasks designed to evaluate those brain functions may use odors as cues. Accurate assessment of olfaction is not only essential for the study of olfactory system but also critical for proper interpretation of various mouse behaviors, especially learning and memory, emotionality and affect, and sociality. Here we describe a series of behavior experiments that offer multidimensional and quantitative assessments for mouse olfactory function, including olfactory habituation, discrimination, odor preference, odor detection sensitivity, and olfactory memory, with respect to both social and nonsocial odors. Copyright © 2015 John Wiley & Sons, Inc.

  3. Sex reversal in vertebrates

    OpenAIRE

    2016-01-01

    This special topic issue of Sexual Development gives an overview of sex reversal in vertebrates, from fishes naturally changing their sex, to rodents escaping the mammalian SRY-determining system. It offers eight up-to-date reviews on specific subjects in sex reversal, considering fishes, amphibians, reptiles, birds, marsupials, and placental mammals, including humans. The broad scope of represented animals makes this ideal for students and researchers, especially those interested in the...

  4. Olfactory bulb encoding during learning under anaesthesia

    Directory of Open Access Journals (Sweden)

    Alister U Nicol

    2014-06-01

    Full Text Available Neural plasticity changes within the olfactory bulb are important for olfactory learning, although how neural encoding changes support new associations with specific odours and whether they can be investigated under anaesthesia, remain unclear. Using the social transmission of food preference olfactory learning paradigm in mice in conjunction with in vivo microdialysis sampling we have shown firstly that a learned preference for a scented food odour smelled on the breath of a demonstrator animal occurs under isofluorane anaesthesia. Furthermore, subsequent exposure to this cued odour under anaesthesia promotes the same pattern of increased release of glutamate and GABA in the olfactory bulb as previously found in conscious animals following olfactory learning, and evoked GABA release was positively correlated with the amount of scented food eaten. In a second experiment, multiarray (24 electrodes electrophysiological recordings were made from olfactory bulb mitral cells under isofluorane anaesthesia before, during and after a novel scented food odour was paired with carbon disulfide. Results showed significant increases in overall firing frequency to the cued-odour during and after learning and decreases in response to an uncued odour. Analysis of patterns of changes in individual neurons revealed that a substantial proportion (>50% of them significantly changed their response profiles during and after learning with most of those previously inhibited becoming excited. A large number of cells exhibiting no response to the odours prior to learning were either excited or inhibited afterwards. With the uncued odour many previously responsive cells became unresponsive or inhibited. Learning associated changes only occurred in the posterior part of the olfactory bulb. Thus olfactory learning under anaesthesia promotes extensive, but spatially distinct, changes in mitral cell networks to both cued and uncued odours as well as in evoked glutamate and

  5. Functional neuroanatomy of Drosophila olfactory memory formation

    OpenAIRE

    Guven-Ozkan, Tugba; Davis, Ronald L.

    2014-01-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying Drosophila learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry exten...

  6. Microencapsulation improves inhibitory effects of transplanted olfactory ensheathing cells on pain after sciatic nerve injury

    Directory of Open Access Journals (Sweden)

    Hao Zhao

    2015-01-01

    Full Text Available Olfactory bulb tissue transplantation inhibits P2X2/3 receptor-mediated neuropathic pain. However, the olfactory bulb has a complex cellular composition, and the mechanism underlying the action of purified transplanted olfactory ensheathing cells (OECs remains unclear. In the present study, we microencapsulated OECs in alginic acid, and transplanted free and microencapsulated OECs into the region surrounding the injured sciatic nerve in rat models of chronic constriction injury. We assessed mechanical nociception in the rat models 7 and 14 days after surgery by measuring paw withdrawal threshold, and examined P2X2/3 receptor expression in L 4-5 dorsal root ganglia using immunohistochemistry. Rats that received free and microencapsulated OEC transplants showed greater withdrawal thresholds than untreated model rats, and weaker P2X2/3 receptor immunoreactivity in dorsal root ganglia. At 14 days, paw withdrawal threshold was much higher in the microencapsulated OEC-treated animals. Our results confirm that microencapsulated OEC transplantation suppresses P2X2/3 receptor expression in L 4-5 dorsal root ganglia in rat models of neuropathic pain and reduces allodynia, and also suggest that transplantation of microencapsulated OECs is more effective than transplantation of free OECs for the treatment of neuropathic pain.

  7. Cortical feedback control of olfactory bulb circuits.

    Science.gov (United States)

    Boyd, Alison M; Sturgill, James F; Poo, Cindy; Isaacson, Jeffry S

    2012-12-20

    Olfactory cortex pyramidal cells integrate sensory input from olfactory bulb mitral and tufted (M/T) cells and project axons back to the bulb. However, the impact of cortical feedback projections on olfactory bulb circuits is unclear. Here, we selectively express channelrhodopsin-2 in olfactory cortex pyramidal cells and show that cortical feedback projections excite diverse populations of bulb interneurons. Activation of cortical fibers directly excites GABAergic granule cells, which in turn inhibit M/T cells. However, we show that cortical inputs preferentially target short axon cells that drive feedforward inhibition of granule cells. In vivo, activation of olfactory cortex that only weakly affects spontaneous M/T cell firing strongly gates odor-evoked M/T cell responses: cortical activity suppresses odor-evoked excitation and enhances odor-evoked inhibition. Together, these results indicate that although cortical projections have diverse actions on olfactory bulb microcircuits, the net effect of cortical feedback on M/T cells is an amplification of odor-evoked inhibition. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. [Deficits in medical counseling in olfactory dysfunction].

    Science.gov (United States)

    Haxel, B R; Nisius, A; Fruth, K; Mann, W J; Muttray, A

    2012-05-01

    Olfactory dysfunctions are common with a prevalence of up to 20% in the population. An impaired sense of smell can lead to specific dangers, therefore, counseling and warning of hazardous situations to raise patient awareness is an important medical function. In this study 105 patients presenting to the University of Mainz Medical Centre with dysosmia were evaluated using a questionnaire. For quantification of the olfactory dysfunction a standardized olfactory test (Sniffin' Sticks) was used. Of the patients 46% were hyposmic and 40% were functionally anosmic. The median duration of the olfactory impairment was 10 months and the main causes of dysosmia were upper respiratory tract infections and idiopathic disorders. More than 90% of the patients consulted an otorhinolaryngologist and 60% a general practitioner before presenting to the University of Mainz Medical Center. More than two thirds of the patients conducted a professional activity, 95% of patients reported that they had not received any medical counseling and 6% of the subjects were forced to discontinue their profession because of olfactory dysfunction. In patients with olfactory dysfunctions appropriate diagnostics, including olfactometry should be performed. Furthermore, correct medical counseling concerning necessary additional arrangements (e.g. installation of smoke or gas detectors, precautions while cooking or for hygiene) has to be performed. For patients in a profession an analysis of the hazards at work is crucial.

  9. CNPase Expression in Olfactory Ensheathing Cells

    Directory of Open Access Journals (Sweden)

    Christine Radtke

    2011-01-01

    Full Text Available A large body of work supports the proposal that transplantation of olfactory ensheathing cells (OECs into nerve or spinal cord injuries can promote axonal regeneration and remyelination. Yet, some investigators have questioned whether the transplanted OECs associate with axons and form peripheral myelin, or if they recruit endogenous Schwann cells that form myelin. Olfactory bulbs from transgenic mice expressing the enhanced green fluorescent protein (eGFP under the control of the 2-3-cyclic nucleotide 3-phosphodiesterase (CNPase promoter were studied. CNPase is expressed in myelin-forming cells throughout their lineage. We examined CNPase expression in both in situ in the olfactory bulb and in vitro to determine if OECs express CNPase commensurate with their myelination potential. eGFP was observed in the outer nerve layer of the olfactory bulb. Dissociated OECs maintained in culture had both intense eGFP expression and CNPase immunostaining. Transplantation of OECs into transected peripheral nerve longitudinally associated with the regenerated axons. These data indicate that OECs in the outer nerve layer of the olfactory bulb of CNPase transgenic mice express CNPase. Thus, while OECs do not normally form myelin on olfactory nerve axons, their expression of CNPase is commensurate with their potential to form myelin when transplanted into injured peripheral nerve.

  10. Insect olfactory memory in time and space.

    Science.gov (United States)

    Liu, Xu; Davis, Ronald L

    2006-12-01

    Recent studies using functional optical imaging have revealed that cellular memory traces form in different areas of the insect brain after olfactory classical conditioning. These traces are revealed as increased calcium signals or synaptic release from defined neurons, and include a short-lived trace that forms immediately after conditioning in antennal lobe projection neurons, an early trace in dopaminergic neurons, and a medium-term trace in dorsal paired medial neurons. New molecular genetic tools have revealed that for normal behavioral memory performance, synaptic transmission from the mushroom body neurons is required only during retrieval, whereas synaptic transmission from dopaminergic neurons is required at the time of acquisition and synaptic transmission from dorsal paired medial neurons is required during the consolidation period. Such experimental results are helping to identify the types of neurons that participate in olfactory learning and when their participation is required. Olfactory learning often occurs alongside crossmodal interactions of sensory information from other modalities. Recent studies have revealed complex interactions between the olfactory and the visual senses that can occur during olfactory learning, including the facilitation of learning about subthreshold olfactory stimuli due to training with concurrent visual stimuli.

  11. Olfactory systems and neural circuits that modulate predator odor fear

    Directory of Open Access Journals (Sweden)

    Lorey K. Takahashi

    2014-03-01

    Full Text Available When prey animals detect the odor of a predator a constellation of fear-related autonomic, endocrine, and behavioral responses rapidly occur to facilitate survival. How olfactory sensory systems process predator odor and channel that information to specific brain circuits is a fundamental issue that is not clearly understood. However, research in the last 15 years has begun to identify some of the essential features of the sensory detection systems and brain structures that underlie predator odor fear. For instance, the main (MOS and accessory olfactory systems (AOS detect predator odors and different types of predator odors are sensed by specific receptors located in either the MOS or AOS. However, complex predator chemosignals may be processed by both the MOS and AOS, which complicate our understanding of the specific neural circuits connected directly and indirectly from the MOS and AOS to activate the physiological and behavioral components of unconditioned and conditioned fear. Studies indicate that brain structures including the dorsal periaqueductal gray, paraventricular nucleus of the hypothalamus, and the medial amygdala appear to be broadly involved in predator odor induced autonomic activity and hypothalamic-pituitary-adrenal stress hormone secretion. The medial amygdala also plays a key role in predator odor unconditioned fear behavior and retrieval of contextual fear memory associated with prior predator odor experiences. Other neural structures including the bed nucleus of the stria terminalis and the ventral hippocampus appear prominently involve in predator odor fear behavior. The basolateral amygdala, medial hypothalamic nuclei, and medial prefrontal cortex are also activated by some but not all predator odors. Future research that characterizes how distinct predator odors are uniquely processed in olfactory systems and neural circuits will provide significant insights into the differences of how diverse predator odors activate

  12. Olfactory systems and neural circuits that modulate predator odor fear

    Science.gov (United States)

    Takahashi, Lorey K.

    2014-01-01

    When prey animals detect the odor of a predator a constellation of fear-related autonomic, endocrine, and behavioral responses rapidly occur to facilitate survival. How olfactory sensory systems process predator odor and channel that information to specific brain circuits is a fundamental issue that is not clearly understood. However, research in the last 15 years has begun to identify some of the essential features of the sensory detection systems and brain structures that underlie predator odor fear. For instance, the main (MOS) and accessory olfactory systems (AOS) detect predator odors and different types of predator odors are sensed by specific receptors located in either the MOS or AOS. However, complex predator chemosignals may be processed by both the MOS and AOS, which complicate our understanding of the specific neural circuits connected directly and indirectly from the MOS and AOS to activate the physiological and behavioral components of unconditioned and conditioned fear. Studies indicate that brain structures including the dorsal periaqueductal gray (DPAG), paraventricular nucleus (PVN) of the hypothalamus, and the medial amygdala (MeA) appear to be broadly involved in predator odor induced autonomic activity and hypothalamic-pituitary-adrenal (HPA) stress hormone secretion. The MeA also plays a key role in predator odor unconditioned fear behavior and retrieval of contextual fear memory associated with prior predator odor experiences. Other neural structures including the bed nucleus of the stria terminalis and the ventral hippocampus (VHC) appear prominently involved in predator odor fear behavior. The basolateral amygdala (BLA), medial hypothalamic nuclei, and medial prefrontal cortex (mPFC) are also activated by some but not all predator odors. Future research that characterizes how distinct predator odors are uniquely processed in olfactory systems and neural circuits will provide significant insights into the differences of how diverse predator

  13. Olfactory proteins mediating chemical communication in the navel orangeworm moth, Amyelois transitella.

    Directory of Open Access Journals (Sweden)

    Walter S Leal

    2009-09-01

    Full Text Available The navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae, is the most serious insect pest of almonds and pistachios in California for which environmentally friendly alternative methods of control--like pheromone-based approaches--are highly desirable. Some constituents of the sex pheromone are unstable and could be replaced with parapheromones, which may be designed on the basis of molecular interaction of pheromones and pheromone-detecting olfactory proteins.By analyzing extracts from olfactory and non-olfactory tissues, we identified putative olfactory proteins, obtained their N-terminal amino acid sequences by Edman degradation, and used degenerate primers to clone the corresponding cDNAs by SMART RACE. Additionally, we used degenerate primers based on conserved sequences of known proteins to fish out other candidate olfactory genes. We expressed the gene encoding a newly identified pheromone-binding protein, which was analyzed by circular dichroism, fluorescence, and nuclear magnetic resonance, and used in a binding assay to assess affinity to pheromone components.We have cloned nine cDNAs encoding olfactory proteins from the navel orangeworm, including two pheromone-binding proteins, two general odorant-binding proteins, one chemosensory protein, one glutathione S-transferase, one antennal binding protein X, one sensory neuron membrane protein, and one odorant receptor. Of these, AtraPBP1 is highly enriched in male antennae. Fluorescence, CD and NMR studies suggest a dramatic pH-dependent conformational change, with high affinity to pheromone constituents at neutral pH and no binding at low pH.

  14. Functional evolution of the trace amine associated receptors in mammals and the loss of TAAR1 in dogs

    Directory of Open Access Journals (Sweden)

    Westmoreland Susan V

    2010-02-01

    Full Text Available Abstract Background The trace amine associated receptor family is a diverse array of GPCRs that arose before the first vertebrates walked on land. Trace amine associated receptor 1 (TAAR1 is a wide spectrum aminergic receptor that acts as a modulator in brain monoaminergic systems. Other trace amine associated receptors appear to relate to environmental perception and show a birth-and-death pattern in mammals similar to olfactory receptors. Results Across mammals, avians, and amphibians, the TAAR1 gene is intact and appears to be under strong purifying selection based on rates of amino acid fixation compared to neutral mutations. We have found that in dogs it has become a pseudogene. Our analyses using a comparative genetics approach revealed that the pseudogenization event predated the emergence of the Canini tribe rather than being coincident with canine domestication. By assessing the effects of the TAAR1 agonist β-phenylethylamine on [3H]dopamine uptake in canine striatal synaptosomes and comparing the degree and pattern of uptake inhibition to that seen in other mammals, including TAAR1 knockout mice, wild type mice and rhesus monkey, we found that the TAAR1 pseudogenization event resulted in an uncompensated loss of function. Conclusion The gene family has seen expansions among certain mammals, notably rodents, and reductions in others, including primates. By placing the trace amine associated receptors in an evolutionary context we can better understand their function and their potential associations with behavior and neurological disease.

  15. Olfactory Fear Conditioning Induces Field Potential Potentiation in Rat Olfactory Cortex and Amygdala

    Science.gov (United States)

    Messaoudi, Belkacem; Granjon, Lionel; Mouly, Anne-Marie; Sevelinges, Yannick; Gervais, Remi

    2004-01-01

    The widely used Pavlovian fear-conditioning paradigms used for studying the neurobiology of learning and memory have mainly used auditory cues as conditioned stimuli (CS). The present work assessed the neural network involved in olfactory fear conditioning, using olfactory bulb stimulation-induced field potential signal (EFP) as a marker of…

  16. Olfactory processing and odor specificity: a meta-analysis of menstrual cycle variation in olfactory sensitivity

    Directory of Open Access Journals (Sweden)

    Martinec Nováková Lenka

    2014-12-01

    Full Text Available Cycle-correlated variation in olfactory threshold, with women becoming more sensitive to odors mid-cycle, is somewhat supported by the literature but the evidence is not entirely consistent, with several studies finding no, or mixed, effects. It has been argued that cyclic shifts in olfactory threshold might be limited to odors relevant to the mating context.

  17. Effect of salinity changes on olfactory memory-related genes and hormones in adult chum salmon Oncorhynchus keta.

    Science.gov (United States)

    Kim, Na Na; Choi, Young Jae; Lim, Sang-Gu; Jeong, Minhwan; Jin, Deuk-Hee; Choi, Cheol Young

    2015-09-01

    Studies of memory formation have recently concentrated on the possible role of N-methyl-d-aspartate receptors (NRs). We examined changes in the expression of three NRs (NR1, NR2B, and NR2C), olfactory receptor (OR), and adrenocorticotropic hormone (ACTH) in chum salmon Oncorhynchus keta using quantitative polymerase chain reaction (QPCR) during salinity change (seawater→50% seawater→freshwater). NRs were significantly detected in the diencephalon and telencephalon and OR was significantly detected in the olfactory epithelium. The expression of NRs, OR, and ACTH increased after the transition to freshwater. We also determined that treatment with MK-801, an antagonist of NRs, decreased NRs in telencephalon cells. In addition, a reduction in salinity was associated with increased levels of dopamine, ACTH, and cortisol (in vivo). Reductions in salinity evidently caused NRs and OR to increase the expression of cortisol and dopamine. We concluded that memory capacity and olfactory imprinting of salmon is related to the salinity of the environment during the migration to spawning sites. Furthermore, salinity affects the memory/imprinting and olfactory abilities, and cortisol and dopamine is also related with olfactory-related memories during migration. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Cellular Mechanisms of Action of Drug Abuse on Olfactory Neurons

    Directory of Open Access Journals (Sweden)

    Thomas Heinbockel

    2015-12-01

    Full Text Available Cannabinoids (Δ9-tetrahydrocannabinol are the active ingredient of marijuana (cannabis which is the most commonly abused illicit drug in the USA. In addition to being known and used as recreational drugs, cannabinoids are produced endogenously by neurons in the brain (endocannabinoids and serve as important signaling molecules in the nervous system and the rest of the body. Cannabinoids have been implicated in bodily processes both in health and disease. Recent pharmacological and physiological experiments have described novel aspects of classic brain signaling mechanisms or revealed unknown mechanisms of cellular communication involving the endocannabinoid system. While several forms of signaling have been described for endocannabinoids, the most distinguishing feature of endocannabinoids is their ability to act as retrograde messengers in neural circuits. Neurons in the main olfactory bulb express high levels of cannabinoid receptors. Here, we describe the cellular mechanisms and function of this novel brain signaling system in regulating neural activity at synapses in olfactory circuits. Results from basic research have the potential to provide the groundwork for translating the neurobiology of drug abuse to the realm of the pharmacotherapeutic treatment of addiction, specifically marijuana substance use disorder.

  19. Coincidence of pheromone and plant odor leads to sensory plasticity in the heliothine olfactory system.

    Directory of Open Access Journals (Sweden)

    Elena Ian

    Full Text Available Male moths possess a highly specialized olfactory system comprised of two segregated sub-arrangements dedicated to processing information about plant odors and pheromones, respectively. Communication between these two sub-systems has been described at the peripheral level, but relatively little is known about putative interactions at subsequent synaptic relays. The male moth faces the challenge of seeking out the conspecific female in a highly dynamic odor world. The female-produced pheromone blend, which is a limited resource serving as guidance for the male, will reach his antennae in intermittent pockets of odor filaments mixed with volatiles from various plants. In the present study we performed calcium imaging for measuring odor-evoked responses in the uni-glomerular antennal-lobe projection neurons (analog to mitral cells in the vertebrate olfactory bulb of Helicoverpa armigera. In order to investigate putative interactions between the two sub-systems tuned to plant volatiles and pheromones, respectively, we performed repeated stimulations with a selection of biologically relevant odors. We found that paired stimulation with a plant odor and the pheromone led to suppressed responses in both sub-systems as compared to those evoked during initial stimulation including application of each odor stimulus alone. The fact that the suppression persisted also after pairing, indicates the existence of a Hebbian-like plasticity in the primary olfactory center established by temporal pairing of the two odor stimulation categories.

  20. Vertebrate gravity sensors as dynamic systems

    Science.gov (United States)

    Ross, M. D.

    1985-01-01

    This paper considers verterbrate gravity receptors as dynamic sensors. That is, it is hypothesized that gravity is a constant force to which an acceleration-sensing system would readily adapt. Premises are considered in light of the presence of kinocilia on hair cells of vertebrate gravity sensors; differences in loading of the sensors among species; and of possible reduction in loading by inclusion of much organic material in otoconia. Moreover, organic-inorganic interfaces may confer a piezoelectric property upon otoconia, which increase the sensitivity of the sensory system to small accelerations. Comparisons with man-made accelerometers are briefly taken up.

  1. Artificial Induction of Associative Olfactory Memory by Optogenetic and Thermogenetic Activation of Olfactory Sensory Neurons and Octopaminergic Neurons in Drosophila Larvae.

    Science.gov (United States)

    Honda, Takato; Lee, Chi-Yu; Honjo, Ken; Furukubo-Tokunaga, Katsuo

    2016-01-01

    The larval brain of Drosophila melanogaster provides an excellent system for the study of the neurocircuitry mechanism of memory. Recent development of neurogenetic techniques in fruit flies enables manipulations of neuronal activities in freely behaving animals. This protocol describes detailed steps for artificial induction of olfactory associative memory in Drosophila larvae. In this protocol, the natural reward signal is substituted by thermogenetic activation of octopaminergic neurons in the brain. In parallel, the odor signal is substituted by optogenetic activation of a specific class of olfactory receptor neurons. Association of reward and odor stimuli is achieved with the concomitant application of blue light and heat that leads to activation of both sets of neurons in living transgenic larvae. Given its operational simplicity and robustness, this method could be utilized to further our knowledge on the neurocircuitry mechanism of memory in the fly brain.

  2. An Olfactory Indicator for Acid-Base Titrations.

    Science.gov (United States)

    Flair, Mark N.; Setzer, William N.

    1990-01-01

    The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)

  3. Radiotherapy of vertebral hemangiomas

    International Nuclear Information System (INIS)

    Sakata, Kohichi; Hareyama, Masato; Oouchi, Atushi; Sido, Mitsuo; Nagakura, Hisayasu; Tamakawa, Mituharu; Akiba, Hidenari; Morita, Kazuo

    1997-01-01

    Between 1975 and 1996, 14 patients (11 females, 3 males) with vertebral hemangioma received treatment with radiotherapy. Thirteen patients had a history of back pain or lumbago and 2 patients had neurological symptoms such as sensory impairment or paraplegia. The standard dose administered was 36 Gy in 18 fractions (five treatments per week). In the 13 patients with pain, this was completely or partially relieved. The condition of a man with hypesthesia of the legs deteriorated and a woman with paraplegia who was treated with decompressive laminectomy followed by radiotherapy recovered completely after irradiation. CT scan before irradiation showed thickened trabeculae as small punctate areas of sclerosis in all patients. At MR imaging before irradiation, T2-weighted MR images showed areas of high intensity in all patients and MR images demonstrated lesion enhancement. However, none of the patients who were treated successfully with radiation demonstrated any changes of the affected vertebra in the conventional radiographic films, CT scan or MR imaging, even 5 years after irradiation. Radiological imaging is indispensable for the diagnosis of vertebral hemangiomas but does not appear to be useful for evaluating the effects of radiotherapy. (orig.)

  4. Kin recognition in zebrafish: a 24-hour window for olfactory imprinting.

    Science.gov (United States)

    Gerlach, Gabriele; Hodgins-Davis, Andrea; Avolio, Carla; Schunter, Celia

    2008-09-22

    Distinguishing kin from non-kin profoundly impacts the evolution of social behaviour. Individuals able to assess the genetic relatedness of conspecifics can preferentially allocate resources towards related individuals and avoid inbreeding. We have addressed the question of how animals acquire the ability to recognize kin by studying the development of olfactory kin preference in zebrafish (Danio rerio). Previously, we showed that zebrafish use an olfactory template to recognize even unfamiliar kin through phenotype matching. Here, we show for the first time that this phenotype matching is based on a learned olfactory imprinting process in which exposure to kin individuals on day 6 post fertilization (pf) is necessary and sufficient for imprinting. Larvae that were exposed to kin before or after but not on day 6 pf did not recognize kin. Larvae isolated from all contact with conspecifics did not imprint on their own chemical cues; therefore, we see no evidence for kin recognition through self-matching in this species. Surprisingly, exposure to non-kin odour during the sensitive phase of development did not result in imprinting on the odour cues of unrelated individuals, suggesting a genetic predisposition to kin odour. Urine-born peptides expressed by genes of the immune system (MHC) are important messengers carrying information about 'self' and 'other'. We suggest that phenotype matching is acquired through a time-sensitive learning process that, in zebrafish, includes a genetic predisposition potentially involving MHC genes expressed in the olfactory receptor neurons.

  5. Dop1 enhances conspecific olfactory attraction by inhibiting miR-9a maturation in locusts.

    Science.gov (United States)

    Guo, Xiaojiao; Ma, Zongyuan; Du, Baozhen; Li, Ting; Li, Wudi; Xu, Lingling; He, Jing; Kang, Le

    2018-03-22

    Dopamine receptor 1 (Dop1) mediates locust attraction behaviors, however, the mechanism by which Dop1 modulates this process remains unknown to date. Here, we identify differentially expressed small RNAs associated with locust olfactory attraction after activating and inhibiting Dop1. Small RNA transcriptome analysis and qPCR validation reveal that Dop1 activation and inhibition downregulates and upregulates microRNA-9a (miR-9a) expression, respectively. miR-9a knockdown in solitarious locusts increases their attraction to gregarious volatiles, whereas miR-9a overexpression in gregarious locusts reduces olfactory attraction. Moreover, miR-9a directly targets adenylyl cyclase 2 (ac2), causing its downregulation at the mRNA and protein levels. ac2 responds to Dop1 and mediates locust olfactory attraction. Mechanistically, Dop1 inhibits miR-9a expression through inducing the dissociation of La protein from pre-miR-9a and resulting in miR-9a maturation inhibition. Our results reveal a Dop1-miR-9a-AC2 circuit that modulates locust olfactory attraction underlying aggregation. This study suggests that miRNAs act as key messengers in the GPCR signaling.

  6. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  7. Mapping of odor-related neuronal activity in the olfactory bulb by high-resolution 2-deoxyglucose autoradiography

    International Nuclear Information System (INIS)

    Lancet, D.; Greer, C.A.; Kauer, J.S.; Shepherd, G.M.

    1982-01-01

    The spatial distribution of odor-induced neuronal activity in the olfactory bulb, the first relay station of the olfactory pathway, is believed to reflect important aspects of chemosensory coding. We report here the application of high-resolution 2-deoxyglucose autoradiography to the mapping of spatial patterns of metabolic activity at the level of single neurons in the olfactory bulb. It was found that glomeruli, which are synaptic complexes containing the first synaptic relay, tend to be uniformly active or inactive during odor exposure. Differential 2-deoxyglucose uptake was also observed in the somata of projection neurons (mitral cells) and interneurons (periglomerular and granule cells). This confirms and extends our previous studies in which odor-specific laminar and focal uptake patterns were revealed by the conventional x-ray film 2-deoxyglucose method due to Sokoloff and colleagues [Sokoloff, L., Reivich, M., Kennedy, C., DesRosiers, M. H., Patlak, C. S., Pettigrew, K. D., Sakurada, O. and Shinohara, M. (1977) J. Neurochem. 28, 897-916]. Based on results obtained by the two methods, it is suggested that the glomerulus as a whole serves as a functional unit of activity. The high-resolution results are interpreted in terms of the well-characterized synaptic organization of the olfactory bulb and also serve to illustrate the capability of the 2-deoxyglucose autoradiographic technique to map metabolic activity in single neurons of the vertebrate central nervous system

  8. Neural Correlates of Olfactory Learning: Critical Role of Centrifugal Neuromodulation

    Science.gov (United States)

    Fletcher, Max L.; Chen, Wei R.

    2010-01-01

    The mammalian olfactory system is well established for its remarkable capability of undergoing experience-dependent plasticity. Although this process involves changes at multiple stages throughout the central olfactory pathway, even the early stages of processing, such as the olfactory bulb and piriform cortex, can display a high degree of…

  9. Development of the ETOC: a European test of olfactory capabilities

    NARCIS (Netherlands)

    Thomas-Danguin, T.; Rouby, C.; Sicard, G.; Vigouroux, M.; Farget, V.; Johanson, A.; Bengtzon, A.; Hall, G.; Ormel, W.; Graaf, de C.; Rousseau, F.; Dumont, J.P.

    2003-01-01

    A number of smell tests designed to evaluate human olfactory capabilities have been published, but none have been validated cross-culturally. The aim of this study was therefore to develop a reliable and quick olfactory test that could be used to evaluate efficiently the olfactory abilities of a

  10. Morphology and physiology of the olfactory system of blood-feeding insects.

    Science.gov (United States)

    Guidobaldi, F; May-Concha, I J; Guerenstein, P G

    2014-01-01

    Several blood-feeding (hematophagous) insects are vectors of a number of diseases including dengue, Chagas disease and leishmaniasis which persistently affect public health throughout Latin America. The vectors of those diseases include mosquitoes, triatomine bugs and sandflies. As vector control is an efficient way to prevent these illnesses it is important to understand the sensory biology of those harmful insects. We study the physiology of the olfactory system of those insects and apply that knowledge on the development of methods to manipulate their behavior. Here we review some of the latest information on insect olfaction with emphasis on hematophagous insects. The insect olfactory sensory neurons are housed inside hair-like organs called sensilla which are mainly distributed on the antenna and mouthparts. The identity of many of the odor compounds that those neurons detect are already known in hematophagous insects. They include several constituents of host (vertebrate) odor, sex, aggregation and alarm pheromones, and compounds related to egg-deposition behavior. Recent work has contributed significant knowledge on how odor information is processed in the insect first odor-processing center in the brain, the antennal lobe. The quality, quantity, and temporal features of the odor stimuli are encoded by the neural networks of the antennal lobe. Information regarding odor mixtures is also encoded. While natural mixtures evoke strong responses, synthetic mixtures that deviate from their natural counterparts in terms of key constituents or proportions of those constituents evoke weaker responses. The processing of olfactory information is largely unexplored in hematophagous insects. However, many aspects of their olfactory behavior are known. As in other insects, responses to relevant single odor compounds are weak while natural mixtures evoke strong responses. Future challenges include studying how information about odor mixtures is processed in their brain

  11. Olfactory circuits and behaviors of nematodes.

    Science.gov (United States)

    Rengarajan, Sophie; Hallem, Elissa A

    2016-12-01

    Over one billion people worldwide are infected with parasitic nematodes. Many parasitic nematodes actively search for hosts to infect using volatile chemical cues, so understanding the olfactory signals that drive host seeking may elucidate new pathways for preventing infections. The free-living nematode Caenorhabditis elegans is a powerful model for parasitic nematodes: because sensory neuroanatomy is conserved across nematode species, an understanding of the microcircuits that mediate olfaction in C. elegans may inform studies of olfaction in parasitic nematodes. Here we review circuit mechanisms that allow C. elegans to respond to odorants, gases, and pheromones. We also highlight work on the olfactory behaviors of parasitic nematodes that lays the groundwork for future studies of their olfactory microcircuits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Histological, Topographical and Ultrastructural Organization of Different Cells Lining the Olfactory Epithelium of Red Piranha, Pygocentrus nattereri (Characiformes, Serrasalmidae

    Directory of Open Access Journals (Sweden)

    Ghosh S. K.

    2016-10-01

    Full Text Available The structural characterization of the olfactory epithelium in Pygocentrus nattereri Kner, 1858 was studied with the help of light as well as scanning and transmission electron microscope. The oval shaped olfactory rosette consisted of 26–28 primary lamellae radiated from midline raphe. The olfactory epithelium of each lamella was well distributed by sensory and non-sensory epithelium. The sensory epithelium contained morphologically distinct ciliated and microvillous receptor cells, supporting cells and basal cells. The non-sensory epithelium was made up of labyrinth cells, mucous cells and stratified epithelial cells. According to TEM investigation elongated rod emerging out from dendrite end of the receptor cells in the free space. The dendrite process of microvillous receptor cells contained microvilli. The supporting cells had lobular nucleus with clearly seen electron dense nucleolus. The apex of the ciliated non-sensory cells was broad and provided with plenty of kinocilia. Basal cells provided with oval nucleus and contained small number of secretory granules. The mucous cells were restricted to the non-sensory areas and the nuclei situated basally and filled with about two-third of the vesicles. The functional significance of various cells lining the olfactory epithelium was discussed with mode of life and living of fish concerned.

  13. Molecular characterization and differential expression of olfactory genes in the antennae of the black cutworm moth Agrotis ipsilon.

    Directory of Open Access Journals (Sweden)

    Shao-Hua Gu

    Full Text Available Insects use their sensitive and selective olfactory system to detect outside chemical odorants, such as female sex pheromones and host plant volatiles. Several groups of olfactory proteins participate in the odorant detection process, including odorant binding proteins (OBPs, chemosensory proteins (CSPs, odorant receptors (ORs, ionotropic receptors (IRs and sensory neuron membrane proteins (SNMPs. The identification and functional characterization of these olfactory proteins will enhance our knowledge of the molecular basis of insect chemoreception. In this study, we report the identification and differential expression profiles of these olfactory genes in the black cutworm moth Agrotis ipsilon. In total, 33 OBPs, 12 CSPs, 42 ORs, 24 IRs, 2 SNMPs and 1 gustatory receptor (GR were annotated from the A. ipsilon antennal transcriptomes, and further RT-PCR and RT-qPCR revealed that 22 OBPs, 3 CSPs, 35 ORs, 14 IRs and the 2 SNMPs are uniquely or primarily expressed in the male and female antennae. Furthermore, one OBP (AipsOBP6 and one CSP (AipsCSP2 were exclusively expressed in the female sex pheromone gland. These antennae-enriched OBPs, CSPs, ORs, IRs and SNMPs were suggested to be responsible for pheromone and general odorant detection and thus could be meaningful target genes for us to study their biological functions in vivo and in vitro.

  14. Linking adult olfactory neurogenesis to social behavior

    Directory of Open Access Journals (Sweden)

    Claudia E Feierstein

    2012-11-01

    Full Text Available In the adult brain, new neurons are added to two brain areas: the olfactory bulb and the hippocampus. Newly-generated neurons integrate into the preexisting circuits, bringing a set of unique properties, such as increased plasticity and responsiveness to stimuli. However, the functional implications of the constant addition of these neurons remain unclear, although they are believed to be important for learning and memory. The levels of neurogenesis are regulated by a variety of environmental factors, as well as during learning, suggesting that new neurons could be important for coping with changing environmental demands. Notably, neurogenesis has been shown to be physiologically regulated in relation to reproductive behavior: neurogenesis increases in female mice upon exposure to cues of the mating partners, during pregnancy and lactation, and in male mice upon exposure to their offspring. In this scenario, and because of the key contribution of olfaction to maternal behavior, we sought to investigate the contribution of adult-generated neurons in the olfactory system to maternal behavior and offspring recognition. To do so, we selectively disrupted neurogenesis in the olfactory pathway of female mice using focal irradiation. Disruption of adult neurogenesis in the olfactory bulb did not affect maternal behavior, or the ability of female mice to discriminate familiar from unfamiliar pups. However, reduction of olfactory neurogenesis resulted in abnormal social interaction of female mice, specifically with male conspecifics. Because the olfactory system is crucial for sex recognition, we suggest that the abnormal interaction with males could result from the inability to detect or discriminate male-specific odors and could therefore have implications for the recognition of potential mating partners. Here, I review the results of this and other studies, and discuss their implications for our understanding of the function of adult neurogenesis.

  15. Enhanced olfactory sensitivity in autism spectrum conditions.

    Science.gov (United States)

    Ashwin, Chris; Chapman, Emma; Howells, Jessica; Rhydderch, Danielle; Walker, Ian; Baron-Cohen, Simon

    2014-01-01

    People with autism spectrum conditions (ASC) report heightened olfaction. Previous sensory experiments in people with ASC have reported hypersensitivity across visual, tactile, and auditory domains, but not olfaction. The aims of the present study were to investigate olfactory sensitivity in ASC, and to test the association of sensitivity to autistic traits. We recruited 17 adult males diagnosed with ASC and 17 typical adult male controls and tested their olfactory sensitivity using the Alcohol Sniff Test (AST), a standardised clinical evaluation of olfactory detection. The AST involves varying the distance between subject and stimulus until an odour is barely detected. Participants with ASC also completed the Autism Spectrum Quotient (AQ) as a measure of autism traits. The ASC group detected the odour at a mean distance of 24.1 cm (SD =11.5) from the nose, compared to the control group, who detected it at a significantly shorter mean distance of 14.4 cm (SD =5.9). Detection distance was independent of age and IQ for both groups, but showed a significant positive correlation with autistic traits in the ASC group (r =0.522). This is the first experimental demonstration, as far as the authors are aware, of superior olfactory perception in ASC and showing that greater olfactory sensitivity is correlated with a higher number of autistic traits. This is consistent with results from previous findings showing hypersensitivity in other sensory domains and may help explain anecdotal and questionnaire accounts of heightened olfactory sensitivity in ASC. Results are discussed in terms of possible underlying neurophysiology.

  16. A computational model of conditioning inspired by Drosophila olfactory system.

    Science.gov (United States)

    Faghihi, Faramarz; Moustafa, Ahmed A; Heinrich, Ralf; Wörgötter, Florentin

    2017-03-01

    Recent studies have demonstrated that Drosophila melanogaster (briefly Drosophila) can successfully perform higher cognitive processes including second order olfactory conditioning. Understanding the neural mechanism of this behavior can help neuroscientists to unravel the principles of information processing in complex neural systems (e.g. the human brain) and to create efficient and robust robotic systems. In this work, we have developed a biologically-inspired spiking neural network which is able to execute both first and second order conditioning. Experimental studies demonstrated that volume signaling (e.g. by the gaseous transmitter nitric oxide) contributes to memory formation in vertebrates and invertebrates including insects. Based on the existing knowledge of odor encoding in Drosophila, the role of retrograde signaling in memory function, and the integration of synaptic and non-synaptic neural signaling, a neural system is implemented as Simulated fly. Simulated fly navigates in a two-dimensional environment in which it receives odors and electric shocks as sensory stimuli. The model suggests some experimental research on retrograde signaling to investigate neural mechanisms of conditioning in insects and other animals. Moreover, it illustrates a simple strategy to implement higher cognitive capabilities in machines including robots. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Vertebral basilar artery dissections

    International Nuclear Information System (INIS)

    Zimmerman, R.A.; Bilaniuk, L.T.; Hackney, D.B.; Grossman, R.I.; Goldberg, H.I.; Atlas, S.W.

    1988-01-01

    Eleven patients (ten male, one female; range, 2-56 years) presented with posterior circulation ischemic symptoms and were evaluated with computed tomography (CT) (eta=11), arteriography (eta=11), and magnetic resonance (MR) imaging (eta=6). Angiography showed dissection of a vertebral artery (eta=8), a basilar artery (eta=1), or a combination of both (eta=2). On CT and/or MR images, infarctions were demonstrated in ten of 11 cases. Most frequently involved were the thalmus (eta=7), cerebellum (eta=6), occipital lobes (eta=4), and pons (eta=3). The site of infarction did not correlate with the side or site of angiographic abnormality. In six cases evaluated by all modalities, MR imaging showed more extensive and widespread infarction than did CT and also showed whether or not the infarcts were hemorrhagic. MR imaging was able to demonstrate the presence of intramural dissecting hematoma prior to angiography and to indicate whether or not flow was reconstituted on follow-up examination

  18. Matrix metalloproteinases outside vertebrates.

    Science.gov (United States)

    Marino-Puertas, Laura; Goulas, Theodoros; Gomis-Rüth, F Xavier

    2017-11-01

    The matrix metalloproteinase (MMP) family belongs to the metzincin clan of zinc-dependent metallopeptidases. Due to their enormous implications in physiology and disease, MMPs have mainly been studied in vertebrates. They are engaged in extracellular protein processing and degradation, and present extensive paralogy, with 23 forms in humans. One characteristic of MMPs is a ~165-residue catalytic domain (CD), which has been structurally studied for 14 MMPs from human, mouse, rat, pig and the oral-microbiome bacterium Tannerella forsythia. These studies revealed close overall coincidence and characteristic structural features, which distinguish MMPs from other metzincins and give rise to a sequence pattern for their identification. Here, we reviewed the literature available on MMPs outside vertebrates and performed database searches for potential MMP CDs in invertebrates, plants, fungi, viruses, protists, archaea and bacteria. These and previous results revealed that MMPs are widely present in several copies in Eumetazoa and higher plants (Tracheophyta), but have just token presence in eukaryotic algae. A few dozen sequences were found in Ascomycota (within fungi) and in double-stranded DNA viruses infecting invertebrates (within viruses). In contrast, a few hundred sequences were found in archaea and >1000 in bacteria, with several copies for some species. Most of the archaeal and bacterial phyla containing potential MMPs are present in human oral and gut microbiomes. Overall, MMP-like sequences are present across all kingdoms of life, but their asymmetric distribution contradicts the vertical descent model from a eubacterial or archaeal ancestor. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Rapid onset aggressive vertebral haemangioma.

    Science.gov (United States)

    Cheung, Nicholas K; Doorenbosch, Xenia; Christie, John G

    2011-03-01

    Vertebral haemangiomas are generally benign asymptomatic vascular tumours seen commonly in the adult population. Presentations in paediatric populations are extremely rare, which can result in rapid onset of neurological symptoms. We present a highly unusual case of an aggressive paediatric vertebral haemangioma causing significant cord compression. A 13-year-old boy presented with only 2 weeks duration of progressive gait disturbance, truncal ataxia and loss of bladder control. Magnetic resonance imaging (MRI) of the spine revealed a large vascular epidural mass extending between T6 and T8 vertebral bodies. Associated displacement and compression of the spinal cord was present. A highly vascular bony lesion was found during surgery. Histopathology identified this tumour to be a vertebral haemangioma. We present an extremely unusual acute presentation of a paediatric vertebral haemangioma. This study highlights the need for early diagnosis, MRI for investigation and urgent surgical management. © Springer-Verlag 2011

  20. Is TrpM5 a reliable marker for chemosensory cells? Multiple types of microvillous cells in the main olfactory epithelium of mice

    Directory of Open Access Journals (Sweden)

    Finger Thomas E

    2008-12-01

    Full Text Available Abstract Background In the past, ciliated receptor neurons, basal cells, and supporting cells were considered the principal components of the main olfactory epithelium. Several studies reported the presence of microvillous cells but their function is unknown. A recent report showed cells in the main olfactory epithelium that express the transient receptor potential channel TrpM5 claiming that these cells are chemosensory and that TrpM5 is an intrinsic signaling component of mammalian chemosensory organs. We asked whether the TrpM5-positive cells in the olfactory epithelium are microvillous and whether they belong to a chemosensory system, i.e. are olfactory neurons or trigeminally-innervated solitary chemosensory cells. Results We investigated the main olfactory epithelium of mice at the light and electron microscopic level and describe several subpopulations of microvillous cells. The ultrastructure of the microvillous cells reveals at least three morphologically different types two of which express the TrpM5 channel. None of these cells have an axon that projects to the olfactory bulb. Tests with a large panel of cell markers indicate that the TrpM5-positive cells are not sensory since they express neither neuronal markers nor are contacted by trigeminal nerve fibers. Conclusion We conclude that TrpM5 is not a reliable marker for chemosensory cells. The TrpM5-positive cells of the olfactory epithelium are microvillous and may be chemoresponsive albeit not part of the sensory apparatus. Activity of these microvillous cells may however influence functionality of local elements of the olfactory system.

  1. Sensors and signal transduction pathways in vertebrate cell volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Pedersen, Stine F

    2006-01-01

    The ability to control cell volume is fundamental for proper cell function. This review highlights recent advances in the understanding of the complex sequences of events by which acute cell volume perturbation alters the activity of osmolyte transport proteins in cells from vertebrate organisms...... will be discussed. In contrast to the simple pathway of osmosensing in yeast, cells from vertebrate organisms appear to exhibit multiple volume sensing systems, the specific mechanism(s) activated being cell type- and stimulus-dependent. Candidate sensors include integrins and growth factor receptors, while other...

  2. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Directory of Open Access Journals (Sweden)

    Julie M Butler

    Full Text Available Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of

  3. Identification and molecular regulation of neural stem cells in the olfactory epithelium

    International Nuclear Information System (INIS)

    Beites, Crestina L.; Kawauchi, Shimako; Crocker, Candice E.; Calof, Anne L.

    2005-01-01

    The sensory neurons that subserve olfaction, olfactory receptor neurons (ORNs), are regenerated throughout life, making the neuroepithelium in which they reside [the olfactory epithelium (OE)] an excellent model for studying how intrinsic and extrinsic factors regulate stem cell dynamics and neurogenesis during development and regeneration. Numerous studies indicate that transcription factors and signaling molecules together regulate generation of ORNs from stem and progenitor cells during development, and work on regenerative neurogenesis indicates that these same factors may operate at postnatal ages as well. This review describes our current knowledge of the identity of the OE neural stem cell; the different cell types that are thought to be the progeny (directly or indirectly) of this stem cell; and the factors that influence cell differentiation in the OE neuronal lineage. We review data suggesting that (1) the ORN lineage contains three distinct proliferating cell types-a stem cell and two populations of transit amplifying cells; (2) in established OE, these three cell types are present within the basal cell compartment of the epithelium; and (3) the stem cell that gives rise ultimately to ORNs may also generate two glial cell types of the primary olfactory pathway: sustentacular cells (SUS), which lie within OE proper; and olfactory ensheathing cells (OEC), which envelope the olfactory nerve. In addition, we describe factors that are both made by and found within the microenvironment of OE stem and progenitor cells, and which exert crucial growth regulatory effects on these cells. Thus, as with other regenerating tissues, the basis of regeneration in the OE appears be a population of stem cells, which resides within a microenvironment (niche) consisting of factors crucial for maintenance of its capacity for proliferation and differentiation

  4. Olfactory disfunction and its relation olfactory bulb volume in Parkinson's disease.

    Science.gov (United States)

    Altinayar, S; Oner, S; Can, S; Kizilay, A; Kamisli, S; Sarac, K

    2014-01-01

    Olfactory dysfunction is the most frequently seen non-motor symptom of Idiopathic Parkinson's disease (IPD). The aim of this study is to analyze selective olfactory dysfunction, and olfactory bulb volume (OBV) in subtypes of IPD, and compare them with those of the healthy controls. Our study included 41 patients with IPD and age and gender matched 19 healthy controls. IPD patients were either tremor dominant (65.9%; TDPD) or non-tremor dominant (34.1%; NTDPD) type. All patients underwent neurological, ear, nose, and throat examinations, and orthonasal olfaction testing. Magnetic resonance imaging (MRI) technique was used to measure the volume of the olfactory bulb. A significant decrease in olfactory identification scores was found in the patient group. The patients had difficulty in discriminating between odors of mothballs, chocolate, Turkish coffee and soap. OBV did not differ between the patient, and the control groups. In the TDPD group, odor identification ability was decreased when compared to the control group. However, odor test results of NTDPD, control and TDPD groups were similar. OBV estimates of the TDPD group were not different from those of the control group, while in the NTDPD group OBVs were found to be decreased. In all patients with Parkinson's disease OBV values did not vary with age of the patients, duration of the disease, age at onset of the disease, and Unified Parkinson's Disease Rating Scale motor scores (UPDRS-m). Olfactory function is a complex process involving olfactory, and cortical structures as well. In Idiopathic Parkinson's disease, changes in OBV do not seem to be directly related to olfactory dysfunction.

  5. Learning-dependent neurogenesis in the olfactory bulb determines long-term olfactory memory.

    Science.gov (United States)

    Sultan, S; Mandairon, N; Kermen, F; Garcia, S; Sacquet, J; Didier, A

    2010-07-01

    Inhibitory interneurons of the olfactory bulb are subjected to permanent adult neurogenesis. Their number is modulated by learning, suggesting that they could play a role in plastic changes of the bulbar network associated with olfactory memory. Adult male C57BL/6 mice were trained in an associative olfactory task, and we analyzed long-term retention of the task 5, 30, and 90 d post-training. In parallel, we assessed the fate of these newborn cells, mapped their distribution in the olfactory bulb and measured their functional implication using the immediate early gene Zif268. In a second set of experiments, we pharmacologically modulated glutamatergic transmission and using the same behavioral task assessed the consequences on memory retention and neurogenesis. Finally, by local infusion of an antimitotic drug, we selectively blocked neurogenesis during acquisition of the task and looked at the effects on memory retention. First we demonstrated that retrieval of an associative olfactory task recruits the newborn neurons in odor-specific areas of the olfactory bulb selected to survive during acquisition of the task and that it does this in a manner that depends on the strength of learning. We then demonstrated that acquisition is not dependent on neurogenesis if long-term retention of the task is abolished by blocking neurogenesis. Adult-born neurons are thus involved in changes in the neural representation of an odor; this underlies long-term olfactory memory as the strength of learning is linked to the duration of this memory. Neurogenesis thus plays a crucial role in long-term olfactory memory.

  6. IGF1-Dependent Synaptic Plasticity of Mitral Cells in Olfactory Memory during Social Learning.

    Science.gov (United States)

    Liu, Zhihui; Chen, Zijun; Shang, Congping; Yan, Fei; Shi, Yingchao; Zhang, Jiajing; Qu, Baole; Han, Hailin; Wang, Yanying; Li, Dapeng; Südhof, Thomas C; Cao, Peng

    2017-07-05

    During social transmission of food preference (STFP), mice form long-term memory of food odors presented by a social partner. How does the brain associate a social context with odor signals to promote memory encoding? Here we show that odor exposure during STFP, but not unconditioned odor exposure, induces glomerulus-specific long-term potentiation (LTP) of synaptic strength selectively at the GABAergic component of dendrodendritic synapses of granule and mitral cells in the olfactory bulb. Conditional deletion of synaptotagmin-10, the Ca 2+ sensor for IGF1 secretion from mitral cells, or deletion of IGF1 receptor in the olfactory bulb prevented the socially relevant GABAergic LTP and impaired memory formation after STFP. Conversely, the addition of IGF1 to acute olfactory bulb slices elicited the GABAergic LTP in mitral cells by enhancing postsynaptic GABA receptor responses. Thus, our data reveal a synaptic substrate for a socially conditioned long-term memory that operates at the level of the initial processing of sensory information. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Changes in Olfactory Sensory Neuron Physiology and Olfactory Perceptual Learning After Odorant Exposure in Adult Mice.

    Science.gov (United States)

    Kass, Marley D; Guang, Stephanie A; Moberly, Andrew H; McGann, John P

    2016-02-01

    The adult olfactory system undergoes experience-dependent plasticity to adapt to the olfactory environment. This plasticity may be accompanied by perceptual changes, including improved olfactory discrimination. Here, we assessed experience-dependent changes in the perception of a homologous aldehyde pair by testing mice in a cross-habituation/dishabituation behavioral paradigm before and after a week-long ester-odorant exposure protocol. In a parallel experiment, we used optical neurophysiology to observe neurotransmitter release from olfactory sensory neuron (OSN) terminals in vivo, and thus compared primary sensory representations of the aldehydes before and after the week-long ester-odorant exposure in individual animals. Mice could not discriminate between the aldehydes during pre-exposure testing, but ester-exposed subjects spontaneously discriminated between the homologous pair after exposure, whereas home cage control mice cross-habituated. Ester exposure did not alter the spatial pattern, peak magnitude, or odorant-selectivity of aldehyde-evoked OSN input to olfactory bulb glomeruli, but did alter the temporal dynamics of that input to make the time course of OSN input more dissimilar between odorants. Together, these findings demonstrate that odor exposure can induce both physiological and perceptual changes in odor processing, and suggest that changes in the temporal patterns of OSN input to olfactory bulb glomeruli could induce differences in odor quality. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Functional Neuroanatomy of "Drosophila" Olfactory Memory Formation

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L.

    2014-01-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying "Drosophila" learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive…

  9. Resistance to Interference of Olfactory Perceptual Learning

    Science.gov (United States)

    Stevenson, Richard J.; Case, Trevor I.; Tomiczek, Caroline

    2007-01-01

    Olfactory memory is especially persistent. The current study explored whether this applies to a form of perceptual learning, in which experience of an odor mixture results in greater judged similarity between its elements. Experiment 1A contrasted 2 forms of interference procedure, "compound" (mixture AW, followed by presentation of new mixtures…

  10. Magnetic resonance imaging of olfactory neuroblastoma

    International Nuclear Information System (INIS)

    Iio, Mitsuhiro; Homma, Akihiro; Furuta, Yasushi; Fukuda, Satoshi

    2006-01-01

    Olfactory neuroblastoma is an uncommon intranasal tumor originating from olfactory neuroepithelium. Despite the development of electron microscopy and immunohistochemical testing, the pathological diagnosis of this tumor is still difficult because of the wide range of histological features. Magnetic resonance imaging (MR) of this tumor and the pattern of contrast enhancement have not been well described. The purpose of this report was to analyze the MR characteristics of olfactory neuroblastomas. The MR signal, pattern of contrast enhancement, and correlation with high-resolution computed tomography (CT) imaging were examined. Seventeen patients with olfactory neuroblastoma were treated at Hokkaido University Hospital and a related hospital during the past 25 years. MR images taken in 12 patients and CT images taken in 9 patients with histologically confirmed olfactory neuroblastoma were retrospectively reviewed. Compared with brain gray matter, 11 tumors were hypointense on T1-weighted images, 9 homogeneously and 2 heterogeneously. Eight tumors were hyperintense on T2-weighted images, 3 homogeneously and 5 heterogeneously, although their appearance was less intense than that of sinusitis. Gadolinium enhancement was moderate in one case and marked in 10 of the 11 cases, 9 homogeneously and 2 heterogeneously. Nine of the 11 tumors showed smooth regular shaped margins; 2 of these tumors exhibited irregular infiltrating margins on gadolinium-enhanced images, compared to the pre-contrast T1-weighted images. Eight of the 11 tumors had clearly demarcated margins, while 3 of the 11 tumors did not exhibit gadolinium enhancement. Six of the 12 cases (50%) exhibited intracranial cysts on the gadolinium-enhanced images. T2-weighted or gadolinium-enhanced images successfully distinguished sinusitis from tumors in 4 cases whereas the CT images failed. Gadolinium enhancement, particularly in the tangential plane, demonstrated intracranial extension not apparent on the CT images

  11. Primary extracranial vertebral artery aneurysms.

    Science.gov (United States)

    Morasch, Mark D; Phade, Sachin V; Naughton, Peter; Garcia-Toca, Manuel; Escobar, Guillermo; Berguer, Ramon

    2013-05-01

    Extracranial vertebral artery aneurysms are uncommon and are usually associated with trauma or dissection. Primary cervical vertebral aneurysms are even rarer and are not well described. The presentation and natural history are unknown and operative management can be difficult. Accessing aneurysms at the skull base can be difficult and, because the frail arteries are often afflicted with connective tissue abnormalities, direct repair can be particularly challenging. We describe the presentation and surgical management of patients with primary extracranial vertebral artery aneurysms. In this study we performed a retrospective, multi-institutional review of patients with primary aneurysms within the extracranial vertebral artery. Between January 2000 and January 2011, 7 patients, aged 12-56 years, were noted to have 9 primary extracranial vertebral artery aneurysms. All had underlying connective tissue or another hereditary disorder, including Ehler-Danlos syndrome (n=3), Marfan's disease (n=2), neurofibromatosis (n=1), and an unspecified connective tissue abnormality (n=1). Eight of 9 aneurysms were managed operatively, including an attempted bypass that ultimately required vertebral ligation; the contralateral aneurysm on this patient has not been treated. Open interventions included vertebral bypass with vein, external carotid autograft, and vertebral transposition to the internal carotid artery. Special techniques were used for handling the anastomoses in patients with Ehler-Danlos syndrome. Although endovascular exclusion was not performed in isolation, 2 hybrid procedures were performed. There were no instances of perioperative stroke or death. Primary extracranial vertebral artery aneurysms are rare and occur in patients with hereditary disorders. Operative intervention is warranted in symptomatic patients. Exclusion and reconstruction may be performed with open and hybrid techniques with low morbidity and mortality. Copyright © 2013 Elsevier Inc. All rights

  12. Electrophysiological characterization of male goldfish (Carassius auratus ventral preoptic area neurons receiving olfactory inputs

    Directory of Open Access Journals (Sweden)

    Wudu E. Lado

    2014-06-01

    Full Text Available Chemical communication via sex pheromones is critical for successful reproduction but the underlying neural mechanisms are not well-understood. The goldfish is a tractable model because sex pheromones have been well-characterized in this species. We used male goldfish forebrain explants in vitro and performed whole-cell current clamp recordings from single neurons in the ventral preoptic area (vPOA to characterize their membrane properties and synaptic inputs from the olfactory bulbs (OB. Principle component and cluster analyses based on intrinsic membrane properties of vPOA neurons (N = 107 revealed five (I-V distinct cell groups. These cells displayed differences in their input resistance (Rinput: I II = IV > III = V. Evidence from electrical stimulation of the OB and application of receptor antagonists suggests that vPOA neurons receive monosynaptic glutamatergic inputs via the medial olfactory tract, with connectivity varying among neuronal groups [I (24%, II (40%, III (0%, IV (34% and V (2%].

  13. Identification of Odorant-Receptor Interactions by Global Mapping of the Human Odorome

    DEFF Research Database (Denmark)

    Audouze, Karine Marie Laure; Tromelin, Anne; Le Bon, Anne Marie

    2014-01-01

    The human olfactory system recognizes a broad spectrum of odorants using approximately 400 different olfactory receptors ( hORs). Although significant improvements of heterologous expression systems used to study interactions between ORs and odorant molecules have been made, screening the olfacto...

  14. Rehabilitation in osteoporotic vertebral fractures

    OpenAIRE

    Pratelli, Elisa; Cinotti, Irene; Pasquetti, Pietro

    2010-01-01

    Vertebral fractures occur particularly in osteoporotic patients due to an increased bone fragility. Vertebral fractures influence the quality of life, mobility and mortality. Preventive training exercises and proprioception reeducation can be utilised for improving posture, balance and level of daily function and for decreasing pain. Quality of life is improved even beyond the active training period. This mini review provides information based on the literature for the rehabilitation of osteo...

  15. Sevoflurane impairs post-operative olfactory memory but preserves olfactory function.

    Science.gov (United States)

    Kostopanagiotou, Georgia; Kalimeris, Konstantinos; Kesidis, Kyriakos; Matsota, Paraskevi; Dima, Cleanthi; Economou, Maria; Papageorgiou, Charalambos

    2011-01-01

    The effect of anaesthesia on olfaction has not been systematically studied. Our aim is to compare the effects of general and regional anaesthesia on olfactory acuity and memory in the immediate post-operative period. Sixty adult patients with the American Society of Anesthesiologists I and II status scheduled for elective minor surgery were included. Exclusion criteria were smoking, alcoholism, psychiatric disease and recent or past airway infection with resulting hyposmia. Patients were randomly allocated to one of three groups (in the analysis, n = 16 in each group): epidural anaesthesia (group E), general anaesthesia with propofol (group P) and general anaesthesia with sevoflurane (group S) of 40-120 min duration. The evening before surgery, at 0.5 and at 3 h post-operatively olfactory acuity and memory were tested, along with blood sampling to measure plasma melatonin and oxytocin levels. Olfactory acuity was tested with successive dilutions of n-butyl-alcohol, and olfactory memory (interpretation of odours) with the University of Pennsylvania Smell Identification Test. Patient characteristics did not differ between groups. Olfactory acuity was intact in all patients, before and after anaesthesia. Olfactory memory deteriorated in group S compared to groups P and E at both post-operative time-points. This was accompanied by a significant post-operative reduction of plasma melatonin levels in group S. Oxytocin levels remained constant in all groups. Our results manifest a specific effect of sevoflurane on olfactory memory, not observed with neuraxial or total intravenous anaesthesia. The misinterpretation of odours in the immediate post-operative period by sevoflurane could be mediated by the decreased levels of melatonin.

  16. Temporal Response Properties of Accessory Olfactory Bulb Neurons: Limitations and Opportunities for Decoding.

    Science.gov (United States)

    Yoles-Frenkel, Michal; Kahan, Anat; Ben-Shaul, Yoram

    2018-05-23

    The vomeronasal system (VNS) is a major vertebrate chemosensory system that functions in parallel to the main olfactory system (MOS). Despite many similarities, the two systems dramatically differ in the temporal domain. While MOS responses are governed by breathing and follow a subsecond temporal scale, VNS responses are uncoupled from breathing and evolve over seconds. This suggests that the contribution of response dynamics to stimulus information will differ between these systems. While temporal dynamics in the MOS are widely investigated, similar analyses in the accessory olfactory bulb (AOB) are lacking. Here, we have addressed this issue using controlled stimulus delivery to the vomeronasal organ of male and female mice. We first analyzed the temporal properties of AOB projection neurons and demonstrated that neurons display prolonged, variable, and neuron-specific characteristics. We then analyzed various decoding schemes using AOB population responses. We showed that compared with the simplest scheme (i.e., integration of spike counts over the entire response period), the division of this period into smaller temporal bins actually yields poorer decoding accuracy. However, optimal classification accuracy can be achieved well before the end of the response period by integrating spike counts within temporally defined windows. Since VNS stimulus uptake is variable, we analyzed decoding using limited information about stimulus uptake time, and showed that with enough neurons, such time-invariant decoding is feasible. Finally, we conducted simulations that demonstrated that, unlike the main olfactory bulb, the temporal features of AOB neurons disfavor decoding with high temporal accuracy, and, rather, support decoding without precise knowledge of stimulus uptake time. SIGNIFICANCE STATEMENT A key goal in sensory system research is to identify which metrics of neuronal activity are relevant for decoding stimulus features. Here, we describe the first systematic

  17. L-glutamate Receptor In Paramecium

    Science.gov (United States)

    Bernal-Martínez, Juan; Ortega-Soto, Arturo

    2004-09-01

    Behavioral, electrophysiological and biochemical experiments were performed in order to establish the presence of a glutamate receptor in the ciliate Paramecium. It was found that an AMPA/KA receptor is functionally expressed in Paramecium and that this receptor is immunologically and fillogenetically related to the AMPA/KA receptor present in vertebrates.

  18. Evolution of the shut-off steps of vertebrate phototransduction

    Science.gov (United States)

    Patel, Hardip R.; Chuah, Aaron

    2018-01-01

    Different isoforms of the genes involved in phototransduction are expressed in vertebrate rod and cone photoreceptors, providing a unique example of parallel evolution via gene duplication. In this study, we determine the molecular phylogeny of the proteins underlying the shut-off steps of phototransduction in the agnathan and jawed vertebrate lineages. For the G-protein receptor kinases (GRKs), the GRK1 and GRK7 divisions arose prior to the divergence of tunicates, with further expansion during the two rounds of whole-genome duplication (2R); subsequently, jawed and agnathan vertebrates retained different subsets of three isoforms of GRK. For the arrestins, gene expansion occurred during 2R. Importantly, both for GRKs and arrestins, the respective rod isoforms did not emerge until the second round of 2R, just prior to the separation of jawed and agnathan vertebrates. For the triplet of proteins mediating shut-off of the G-protein transducin, RGS9 diverged from RGS11, probably at the second round of 2R, whereas Gβ5 and R9AP appear not to have undergone 2R expansion. Overall, our analysis provides a description of the duplications and losses of phototransduction shut-off genes that occurred during the transition from a chordate with only cone-like photoreceptors to an ancestral vertebrate with both cone- and rod-like photoreceptors. PMID:29321241

  19. Olfactory bulb proteins linked to olfactory memory in C57BL/6J mice.

    Science.gov (United States)

    Li, Lin; Mauric, Veronika; Zheng, Jun-Fang; Kang, Sung Ung; Patil, Sudarshan; Höger, Harald; Lubec, Gert

    2010-08-01

    Information on systematic analysis of olfactory memory-related proteins is poor. In this study, the odor discrimination task to investigate olfactory recognition memory of adult male C57BL/6J mice was used. Subsequently, olfactory bulbs (OBs) were taken, proteins extracted, and run on two-dimensional gel electrophoresis with in-gel-protein digestion, followed by mass spectrometry and quantification of differentially expressed proteins. Dual specificity mitogen-activated protein kinase kinase 1 (MEK1), dihydropyrimidinase-related protein 1 (DRP1), and fascin are related with Lemon odor memory. Microtubule-associated protein RP/EB family member 3 is related to Rose odor memory. Hypoxanthine-guanine phosphoribosyltransferase is related with both Lemon and Rose odors memory. MEK1 and DRP1 levels were increased, while microtubule-associated protein RP/EB family member 3, fascin and hypoxanthine-guanine phosphoribosyltransferase levels were decreased during olfactory memory. In summary, neurogenesis, signal transduction, cytoskeleton, and nucleotide metabolism are involved in olfactory memory formation and storage of C57BL/6J mice.

  20. File list: Unc.Oth.10.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Oth.10.AllAg.Olfactory_epithelium mm9 Unclassified Others Olfactory epithelium ...SRX112960 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.10.AllAg.Olfactory_epithelium.bed ...

  1. File list: Unc.Oth.20.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Oth.20.AllAg.Olfactory_epithelium mm9 Unclassified Others Olfactory epithelium ...SRX112960 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.20.AllAg.Olfactory_epithelium.bed ...

  2. File list: Unc.Oth.05.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Oth.05.AllAg.Olfactory_epithelium mm9 Unclassified Others Olfactory epithelium ...SRX112960 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.05.AllAg.Olfactory_epithelium.bed ...

  3. Olfactory neuroblastoma complicated by postirradiation pneumocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Fusejima, Toru; Matsumura, Kenichirou; Hayano, Makoto [Mito Saiseikai Hospital (Japan)

    1990-11-01

    A 56-year-old male was admitted with the complaints of nasal bleeding, gait disturbance, and disturbance of consciousness. Neurological examination revealed drowsiness, right hemiparesis, and choked discs. Computed tomography scan showed an enhanced mass at the frontal base, which extended to the left nasal and paranasal cavities. Angiography showed a tumor stain with a mass sign. The intracranial part of the tumor was removed completely and he was discharged ambulatorily. Two months after surgery, however, he was admitted again for the regrowth of the tumor. Ventriculoperitoneal shunting was emplaced and radiation therapy was given to the brain and nasal cavity. After 3000 rad irradiation the clinical condition suddenly became worse because of pneumocephalus. The cranial tumor disappeared after irradiation but he died of metastases and general prostration. Clinically this case was diagnosed as an olfactory groove meningioma at first, but immunohistochemical diagnosis was olfactory neuroblastoma. (author).

  4. MRI of the olfactory bulbs and sulci in human fetuses

    International Nuclear Information System (INIS)

    Azoulay, Robin; Grabar, Sophie; Kalifa, Gabriel; Adamsbaum, Catherine; Fallet-Bianco, Catherine; Garel, Catherine

    2006-01-01

    There is limited knowledge of the MRI pattern of the development of fetal olfactory bulbs and sulci. To describe the MRI appearance of olfactory bulbs and sulci in normal in vivo fetuses according to gestational age. Olfactory bulbs and sulci were retrospectively assessed on brain MRI examinations of 88 normal fetuses between 24 and 39 weeks gestational age. Two reference centres were involved in the study and both used routine protocols that included axial and coronal T2- and T1-weighted sequences at 1.5 T. The results were compared both with the commonly used neuropathological data in the literature and with personal neuropathological data. Pearson's chi-squared test or Fisher's exact test were performed. One case of olfactory agenesis associated with CHARGE syndrome was identified. T2-weighted coronal sequences were the most sensitive for detecting olfactory bulbs and sulci. Olfactory sulci were significantly better detected from 30 weeks onwards (90.9-100%; P<0.001). MRI showed a posteroanterior development of these sulci. Olfactory bulbs were better detected from 30 to 34 weeks (80-90.9%; P<0.002). Comparison with neuropathological data confirmed the posteroanterior development of the sulci and showed an important delay in detection of the olfactory structures (bulbs and sulci). No difference was observed between the two centres involved. To date, fetal MRI can depict olfactory sulci from 30 weeks gestational age onwards and olfactory bulbs from 30 to 34 weeks gestational age. This preliminary reference standard is useful to assess the normality of the olfactory system and to diagnose olfactory agenesis. (orig.)

  5. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  6. Functional neuroanatomy of Drosophila olfactory memory formation.

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L

    2014-10-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying Drosophila learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry extending from the site(s) of acquisition to the site(s) controlling memory expression? (3) How is information processed across this circuit to consolidate early-forming, disruptable memories to stable, late memories? Much progress has been made and a few strong conclusions have emerged: (1) Acquisition occurs at multiple sites within the olfactory nervous system but is mediated predominantly by the γ mushroom body neurons. (2) The expression of long-term memory is completely dependent on the synaptic output of α/β mushroom body neurons. (3) Consolidation occurs, in part, through circuit interactions between mushroom body and dorsal paired medial neurons. Despite this progress, a complete and unified model that details the pathway from acquisition to memory expression remains elusive. © 2014 Guven-Ozkan and Davis; Published by Cold Spring Harbor Laboratory Press.

  7. Humans and mice express similar olfactory preferences.

    Directory of Open Access Journals (Sweden)

    Nathalie Mandairon

    Full Text Available In humans, the pleasantness of odors is a major contributor to social relationships and food intake. Smells evoke attraction and repulsion responses, reflecting the hedonic value of the odorant. While olfactory preferences are known to be strongly modulated by experience and learning, it has been recently suggested that, in humans, the pleasantness of odors may be partly explained by the physicochemical properties of the odorant molecules themselves. If odor hedonic value is indeed predetermined by odorant structure, then it could be hypothesized that other species will show similar odor preferences to humans. Combining behavioral and psychophysical approaches, we here show that odorants rated as pleasant by humans were also those which, behaviorally, mice investigated longer and human subjects sniffed longer, thereby revealing for the first time a component of olfactory hedonic perception conserved across species. Consistent with this, we further show that odor pleasantness rating in humans and investigation time in mice were both correlated with the physicochemical properties of the molecules, suggesting that olfactory preferences are indeed partly engraved in the physicochemical structure of the odorant. That odor preferences are shared between mammal species and are guided by physicochemical features of odorant stimuli strengthens the view that odor preference is partially predetermined. These findings open up new perspectives for the study of the neural mechanisms of hedonic perception.

  8. Disrupted Olfactory Integration in Schizophrenia: Functional Connectivity Study.

    Science.gov (United States)

    Kiparizoska, Sara; Ikuta, Toshikazu

    2017-09-01

    Evidence for olfactory dysfunction in schizophrenia has been firmly established. However, in the typical understanding of schizophrenia, olfaction is not recognized to contribute to or interact with the illness. Despite the solid presence of olfactory dysfunction in schizophrenia, its relation to the rest of the illness remains largely unclear. Here, we aimed to examine functional connectivity of the olfactory bulb, olfactory tract, and piriform cortices and isolate the network that would account for the altered olfaction in schizophrenia. We examined the functional connectivity of these specific olfactory regions in order to isolate other brain regions associated with olfactory processing in schizophrenia. Using the resting state functional MRI data from the Center for Biomedical Research Excellence in Brain Function and Mental Illness, we compared 84 patients of schizophrenia and 90 individuals without schizophrenia. The schizophrenia group showed disconnectivity between the anterior piriform cortex and the nucleus accumbens, between the posterior piriform cortex and the middle frontal gyrus, and between the olfactory tract and the visual cortices. The current results suggest functional disconnectivity of olfactory regions in schizophrenia, which may account for olfactory dysfunction and disrupted integration with other sensory modalities in schizophrenia. © The Author 2017. Published by Oxford University Press on behalf of CINP.

  9. Anatomy, histochemistry and immunohistochemistry of the olfactory subsystems in mice

    Directory of Open Access Journals (Sweden)

    Arthur William Barrios

    2014-07-01

    Full Text Available The four regions of the murine nasal cavity featuring olfactory neurons were studied anatomically and by labelling with lectins and relevant antibodies with a view to establishing criteria for the identification of olfactory subsystems that are readily applicable to other mammals. In the main olfactory epithelium and the septal organ the olfactory sensory neurons (OSNs are embedded in quasi-stratified columnar epithelium; vomeronasal OSNs are embedded in epithelium lining the medial interior wall of the vomeronasal duct and do not make contact with the mucosa of the main nasal cavity; and in Grüneberg’s ganglion a small isolated population of OSNs lies adjacent to, but not within, the epithelium. With the exception of Grüneberg’s ganglion, all the tissues expressing olfactory marker protein (OMP (the above four nasal territories, the vomeronasal and main olfactory nerves, and the main and accessory olfactory bulbs are also labelled by Lycopersicum esculentum agglutinin, while Ulex europaeus agglutinin I labels all and only tissues expressing Gi2 (the apical sensory neurons of the vomeronasal organ, their axons, and their glomerular destinations in the anterior accessory olfactory bulb. These staining patterns of UEA-I and LEA may facilitate the characterization of olfactory anatomy in other species. A 710-section atlas of the anatomy of the murine nasal cavity has been made available on line.

  10. Apolipoprotein E4 causes early olfactory network abnormalities and short-term olfactory memory impairments.

    Science.gov (United States)

    Peng, Katherine Y; Mathews, Paul M; Levy, Efrat; Wilson, Donald A

    2017-02-20

    While apolipoprotein (Apo) E4 is linked to increased incidence of Alzheimer's disease (AD), there is growing evidence that it plays a role in functional brain irregularities that are independent of AD pathology. However, ApoE4-driven functional differences within olfactory processing regions have yet to be examined. Utilizing knock-in mice humanized to ApoE4 versus the more common ApoE3, we examined a simple olfactory perceptual memory that relies on the transfer of information from the olfactory bulb (OB) to the piriform cortex (PCX), the primary cortical region involved in higher order olfaction. In addition, we have recorded in vivo resting and odor-evoked local field potentials (LPF) from both brain regions and measured corresponding odor response magnitudes in anesthetized young (6-month-old) and middle-aged (12-month-old) ApoE mice. Young ApoE4 compared to ApoE3 mice exhibited a behavioral olfactory deficit coinciding with hyperactive odor-evoked response magnitudes within the OB that were not observed in older ApoE4 mice. Meanwhile, middle-aged ApoE4 compared to ApoE3 mice exhibited heightened response magnitudes in the PCX without a corresponding olfactory deficit, suggesting a shift with aging in ApoE4-driven effects from OB to PCX. Interestingly, the increased ApoE4-specific response in the PCX at middle-age was primarily due to a dampening of baseline spontaneous activity rather than an increase in evoked response power. Our findings indicate that early ApoE4-driven olfactory memory impairments and OB network abnormalities may be a precursor to later network dysfunction in the PCX, a region that not only is targeted early in AD, but may be selectively vulnerable to ApoE4 genotype. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Retro- and orthonasal olfactory function in relation to olfactory bulb volume in patients with hypogonadotrophic hypogonadism.

    Science.gov (United States)

    Salihoglu, Murat; Kurt, Onuralp; Ay, Seyid Ahmet; Baskoy, Kamil; Altundag, Aytug; Saglam, Muzaffer; Deniz, Ferhat; Tekeli, Hakan; Yonem, Arif; Hummel, Thomas

    2017-08-24

    Idiopathic hypogonadotrophic hypogonadism (IHH) with an olfactory deficit is defined as Kallmann syndrome (KS) and is distinct from normosmic IHH. Because olfactory perception not only consists of orthonasally gained impressions but also involves retronasal olfactory function, in this study we decided to comprehensively evaluate both retronasal and orthonasal olfaction in patients with IHH. This case-control study included 31 controls and 45 IHH patients. All participants whose olfactory and taste functions were evaluated with orthonasal olfaction (discrimination, identification and threshold), retronasal olfaction, taste function and olfactory bulb volume (OBV) measurement. The patients were separated into three groups according to orthonasal olfaction: anosmic IHH (aIHH), hyposmic IHH (hIHH) and normosmic IHH (nIHH). Discrimination, identification and threshold scores of patients with KS were significantly lower than controls. Threshold scores of patients with nIHH were significantly lower than those of controls, but discrimination and identification scores were not significantly different. Retronasal olfaction was reduced only in the aIHH group compared to controls. Identification of bitter, sweet, sour, and salty tastes was not significantly different when compared between the anosmic, hyposmic, and normosmic IHH groups and controls. OBV was lower bilaterally in all patient groups when compared with controls. The OBV of both sides was found to be significantly correlated with TDI scores in IHH patients. 1) There were no significant differences in gustatory function between controls and IHH patients; 2) retronasal olfaction was reduced only in anosmic patients but not in orthonasally hyposmic participants, possibly indicating presence of effective compensatory mechanisms; 3) olfactory bulb volumes were highly correlated with olfaction scores in the HH group. The current results indicate a continuum from anosmia to normosmia in IHH patients. Copyright © 2017

  12. Chromatin modification of Notch targets in olfactory receptor neuron diversification

    Czech Academy of Sciences Publication Activity Database

    Endo, K.; Karim, M. R.; Taniguchi, H.; Krejčí, Alena; Kinameri, E.; Siebert, M.; Ito, K.; Bray, S. J.; Moore, A. W.

    2012-01-01

    Roč. 15, č. 2 (2012), s. 224-233 ISSN 1097-6256 Institutional research plan: CEZ:AV0Z50070508 Keywords : neuron diversification Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 15.251, year: 2012

  13. Evolution of vertebrate adaptive immunity: immune cells and tissues, and AID/APOBEC cytidine deaminases.

    Science.gov (United States)

    Hirano, Masayuki

    2015-08-01

    All surviving jawed vertebrate representatives achieve diversity in immunoglobulin-based B and T cell receptors for antigen recognition through recombinatorial rearrangement of V(D)J segments. However, the extant jawless vertebrates, lampreys and hagfish, instead generate three types of variable lymphocyte receptors (VLRs) through a template-mediated combinatorial assembly of different leucine-rich repeat (LRR) sequences. The clonally diverse VLRB receptors are expressed by B-like lymphocytes, while the VLRA and VLRC receptors are expressed by lymphocyte lineages that resemble αβ and γδ T lymphocytes, respectively. These findings suggest that three basic types of lymphocytes, one B-like and two T-like, are an essential feature of vertebrate adaptive immunity. Around 500 million years ago, a common ancestor of jawed and jawless vertebrates evolved a genetic program for the development of prototypic lymphoid cells as a foundation for an adaptive immune system. This acquisition preceded the convergent evolution of alternative types of clonally diverse receptors for antigens in all vertebrates, as reviewed in this article. © 2015 WILEY Periodicals, Inc.

  14. Involvement of hormones in olfactory imprinting and homing in chum salmon.

    Science.gov (United States)

    Ueda, Hiroshi; Nakamura, Shingo; Nakamura, Taro; Inada, Kaoru; Okubo, Takashi; Furukawa, Naohiro; Murakami, Reiichi; Tsuchida, Shigeo; Zohar, Yonathan; Konno, Kotaro; Watanabe, Masahiko

    2016-02-16

    The olfactory hypothesis for salmon imprinting and homing to their natal stream is well known, but the endocrine hormonal control mechanisms of olfactory memory formation in juveniles and retrieval in adults remain unclear. In brains of hatchery-reared underyearling juvenile chum salmon (Oncorhynchus keta), thyrotropin-releasing hormone gene expression increased immediately after release from a hatchery into the natal stream, and the expression of the essential NR1 subunit of the N-methyl-D-aspartate receptor increased during downstream migration. Gene expression of salmon gonadotropin-releasing hormone (sGnRH) and NR1 increased in the adult chum salmon brain during homing from the Bering Sea to the natal hatchery. Thyroid hormone treatment in juveniles enhanced NR1 gene activation, and GnRHa treatment in adults improved stream odour discrimination. Olfactory memory formation during juvenile downstream migration and retrieval during adult homing migration of chum salmon might be controlled by endocrine hormones and could be clarified using NR1 as a molecular marker.

  15. Olfactory map formation in the Drosophila brain: genetic specificity and neuronal variability.

    Science.gov (United States)

    Brochtrup, Anna; Hummel, Thomas

    2011-02-01

    The development of the Drosophila olfactory system is a striking example of how genetic programs specify a large number of different neuron types and assemble them into functional circuits. To ensure precise odorant perception, each sensory neuron has to not only select a single olfactory receptor (OR) type out of a large genomic repertoire but also segregate its synaptic connections in the brain according to the OR class identity. Specification and patterning of second-order interneurons in the olfactory brain center occur largely independent of sensory input, followed by a precise point-to-point matching of sensory and relay neurons. Here we describe recent progress in the understanding of how cell-intrinsic differentiation programs and context-dependent cellular interactions generate a stereotyped sensory map in the Drosophila brain. Recent findings revealed an astonishing morphological diversity among members of the same interneuron class, suggesting an unexpected variability in local microcircuits involved in insect sensory processing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Olfactory memory formation and the influence of reward pathway during appetitive learning by honey bees.

    Science.gov (United States)

    Wright, Geraldine A; Mustard, Julie A; Kottcamp, Sonya M; Smith, Brian H

    2007-11-01

    Animals possess the ability to assess food quality via taste and via changes in state that occur after ingestion. Here, we investigate the extent to which a honey bee's ability to assess food quality affected the formation of association with an odor stimulus and the retention of olfactory memories associated with reward. We used three different conditioning protocols in which the unconditioned stimulus (food) was delivered as sucrose stimulation to the proboscis (mouthparts), the antennae or to both proboscis and antennae. All means of delivery of the unconditioned stimulus produced robust associative conditioning with an odor. However, the memory of a conditioned odor decayed at a significantly greater rate for subjects experiencing antennal-only stimulation after either multiple- or single-trial conditioning. Finally, to test whether the act of feeding on a reward containing sucrose during conditioning affected olfactory memory formation, we conditioned honey bees to associate an odor with antennal stimulation with sucrose followed by feeding on a water droplet. We observed that a honey bee's ability to recall the conditioned odor was not significantly different from that of subjects conditioned with an antennal-only sucrose stimulus. Our results show that stimulation of the sensory receptors on the proboscis and/or ingestion of the sucrose reward during appetitive olfactory conditioning are necessary for long-term memory formation.

  17. Olfactory responses to natal stream water in sockeye salmon by BOLD fMRI.

    Directory of Open Access Journals (Sweden)

    Hiroshi Bandoh

    Full Text Available Many studies have shown that juvenile salmon imprint olfactory memory of natal stream odors during downstream migration, and adults recall this stream-specific odor information to discriminate their natal stream during upstream migration for spawning. The odor information processing of the natal stream in the salmon brain, however, has not been clarified. We applied blood oxygenation level-dependent (BOLD functional magnetic resonance imaging to investigate the odor information processing of the natal stream in the olfactory bulb and telencephalon of lacustrine sockeye salmon (Oncorhynchus nerka. The strong responses to the natal stream water were mainly observed in the lateral area of dorsal telencephalon (Dl, which are homologous to the medial pallium (hippocampus in terrestrial vertebrates. Although the concentration of L-serine (1 mM in the control water was 20,000-times higher than that of total amino acid in the natal stream water (47.5 nM, the BOLD signals resulting from the natal stream water were stronger than those by L-serine in the Dl. We concluded that sockeye salmon could process the odor information of the natal stream by integrating information in the Dl area of the telencephalon.

  18. In Vivo Study of Dynamics and Stability of Dendritic Spines on Olfactory Bulb Interneurons in Xenopus laevis Tadpoles.

    Directory of Open Access Journals (Sweden)

    Yu-Bin Huang

    Full Text Available Dendritic spines undergo continuous remodeling during development of the nervous system. Their stability is essential for maintaining a functional neuronal circuit. Spine dynamics and stability of cortical excitatory pyramidal neurons have been explored extensively in mammalian animal models. However, little is known about spiny interneurons in non-mammalian vertebrate models. In the present study, neuronal morphology was visualized by single-cell electroporation. Spiny neurons were surveyed in the Xenopus tadpole brain and observed to be widely distributed in the olfactory bulb and telencephalon. DsRed- or PSD95-GFP-expressing spiny interneurons in the olfactory bulb were selected for in vivo time-lapse imaging. Dendritic protrusions were classified as filopodia, thin, stubby, or mushroom spines based on morphology. Dendritic spines on the interneurons were highly dynamic, especially the filopodia and thin spines. The stubby and mushroom spines were relatively more stable, although their stability significantly decreased with longer observation intervals. The 4 spine types exhibited diverse preferences during morphological transitions from one spine type to others. Sensory deprivation induced by severing the olfactory nerve to block the input of mitral/tufted cells had no significant effects on interneuron spine stability. Hence, a new model was established in Xenopus laevis tadpoles to explore dendritic spine dynamics in vivo.

  19. Vertebrate pressure-gradient receivers

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob

    2011-01-01

    The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some of the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction of sound arriving at both sides of the eardrum and stro......The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some of the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction of sound arriving at both sides of the eardrum....... Recent vertebrates form a continuum from perfect interaural transmission (0 dB in a certain frequency band) and pronounced eardrum directionality (30-40 dB) in the lizards, over somewhat attenuated transmission and limited directionality in birds and frogs, to the strongly attenuated interaural...

  20. Dendritic branching of olfactory bulb mitral and tufted cells: regulation by TrkB.

    Directory of Open Access Journals (Sweden)

    Fumiaki Imamura

    2009-08-01

    Full Text Available Projection neurons of mammalian olfactory bulb (OB, mitral and tufted cells, have dendrites whose morphologies are specifically differentiated for efficient odor information processing. The apical dendrite extends radially and arborizes in single glomerulus where it receives primary input from olfactory sensory neurons that express the same odor receptor. The lateral dendrites extend horizontally in the external plexiform layer and make reciprocal dendrodendritic synapses with granule cells, which moderate mitral/tufted cell activity. The molecular mechanisms regulating dendritic development of mitral/tufted cells is one of the unsolved important problems in the olfactory system. Here, we focused on TrkB receptors to test the hypothesis that neurotrophin-mediate mechanisms contributed to dendritic differentiation of OB mitral/tufted cells.With immunohistochemical analysis, we found that the TrkB neurotrophin receptor is expressed by both apical and lateral dendrites of mitral/tufted cells and that expression is evident during the early postnatal days when these dendrites exhibit their most robust growth and differentiation. To examine the effect of TrkB activation on mitral/tufted cell dendritic development, we cultured OB neurons. When BDNF or NT4 were introduced into the cultures, there was a significant increase in the number of primary neurites and branching points among the mitral/tufted cells. Moreover, BDNF facilitated filopodial extension along the neurites of mitral/tufted cells.In this report, we show for the first time that TrkB activation stimulates the dendritic branching of mitral/tufted cells in developing OB. This suggests that arborization of the apical dendrite in a glomerulus is under the tight regulation of TrkB activation.

  1. Analysis of the Antennal Transcriptome and Insights into Olfactory Genes in Hyphantria cunea (Drury).

    Science.gov (United States)

    Zhang, Long-Wa; Kang, Ke; Jiang, Shi-Chang; Zhang, Ya-Nan; Wang, Tian-Tian; Zhang, Jing; Sun, Long; Yang, Yun-Qiu; Huang, Chang-Chun; Jiang, Li-Ya; Ding, De-Gui

    2016-01-01

    Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) is an invasive insect pest which, in China, causes unprecedented damage and economic losses due to its extreme fecundity and wide host range, including forest and shade trees, and even crops. Compared to the better known lepidopteran species which use Type-I pheromones, little is known at the molecular level about the olfactory mechanisms of host location and mate choice in H. cunea, a species using Type-II lepidopteran pheromones. In the present study, the H. cunea antennal transcriptome was constructed by Illumina Hiseq 2500TM sequencing, with the aim of discovering olfaction-related genes. We obtained 64,020,776 clean reads, and 59,243 unigenes from the analysis of the transcriptome, and the putative gene functions were annotated using gene ontology (GO) annotation. We further identified 124 putative chemosensory unigenes based on homology searches and phylogenetic analysis, including 30 odorant binding proteins (OBPs), 17 chemosensory proteins (CSPs), 52 odorant receptors (ORs), 14 ionotropic receptors (IRs), nine gustatory receptors (GRs) and two sensory neuron membrane proteins (SNMPs). We also found many conserved motif patterns of OBPs and CSPs using a MEME system. Moreover, we systematically analyzed expression patterns of OBPs and CSPs based on reverse transcription PCR and quantitative real time PCR (RT-qPCR) with RNA extracted from different tissues and life stages of both sexes in H. cunea. The antennae-biased expression may provide a deeper further understanding of olfactory processing in H. cunea. The first ever identification of olfactory genes in H. cunea may provide new leads for control of this major pest.

  2. Analysis of the Antennal Transcriptome and Insights into Olfactory Genes in Hyphantria cunea (Drury.

    Directory of Open Access Journals (Sweden)

    Long-Wa Zhang

    Full Text Available Hyphantria cunea (Drury (Lepidoptera: Arctiidae is an invasive insect pest which, in China, causes unprecedented damage and economic losses due to its extreme fecundity and wide host range, including forest and shade trees, and even crops. Compared to the better known lepidopteran species which use Type-I pheromones, little is known at the molecular level about the olfactory mechanisms of host location and mate choice in H. cunea, a species using Type-II lepidopteran pheromones. In the present study, the H. cunea antennal transcriptome was constructed by Illumina Hiseq 2500TM sequencing, with the aim of discovering olfaction-related genes. We obtained 64,020,776 clean reads, and 59,243 unigenes from the analysis of the transcriptome, and the putative gene functions were annotated using gene ontology (GO annotation. We further identified 124 putative chemosensory unigenes based on homology searches and phylogenetic analysis, including 30 odorant binding proteins (OBPs, 17 chemosensory proteins (CSPs, 52 odorant receptors (ORs, 14 ionotropic receptors (IRs, nine gustatory receptors (GRs and two sensory neuron membrane proteins (SNMPs. We also found many conserved motif patterns of OBPs and CSPs using a MEME system. Moreover, we systematically analyzed expression patterns of OBPs and CSPs based on reverse transcription PCR and quantitative real time PCR (RT-qPCR with RNA extracted from different tissues and life stages of both sexes in H. cunea. The antennae-biased expression may provide a deeper further understanding of olfactory processing in H. cunea. The first ever identification of olfactory genes in H. cunea may provide new leads for control of this major pest.

  3. Photoperiod mediated changes in olfactory bulb neurogenesis and olfactory behavior in male white-footed mice (Peromyscus leucopus.

    Directory of Open Access Journals (Sweden)

    James C Walton

    Full Text Available Brain plasticity, in relation to new adult mammalian neurons generated in the subgranular zone of the hippocampus, has been well described. However, the functional outcome of new adult olfactory neurons born in the subventricular zone of the lateral ventricles is not clearly defined, as manipulating neurogenesis through various methods has given inconsistent and conflicting results in lab mice. Several small rodent species, including Peromyscus leucopus, display seasonal (photoperiodic brain plasticity in brain volume, hippocampal function, and hippocampus-dependent behaviors; plasticity in the olfactory system of photoperiodic rodents remains largely uninvestigated. We exposed adult male P. leucopus to long day lengths (LD and short day lengths (SD for 10 to 15 weeks and then examined olfactory bulb cell proliferation and survival using the thymidine analog BrdU, olfactory bulb granule cell morphology using Golgi-Cox staining, and behavioral investigation of same-sex conspecific urine. SD mice did not differ from LD counterparts in granular cell morphology of the dendrites or in dendritic spine density. Although there were no differences due to photoperiod in habituation to water odor, SD mice rapidly habituated to male urine, whereas LD mice did not. In addition, short day induced changes in olfactory behavior were associated with increased neurogenesis in the caudal plexiform and granule cell layers of the olfactory bulb, an area known to preferentially respond to water-soluble odorants. Taken together, these data demonstrate that photoperiod, without altering olfactory bulb neuronal morphology, alters olfactory bulb neurogenesis and olfactory behavior in Peromyscus leucopus.

  4. Jamb and jamc are essential for vertebrate myocyte fusion.

    Directory of Open Access Journals (Sweden)

    Gareth T Powell

    2011-12-01

    Full Text Available Cellular fusion is required in the development of several tissues, including skeletal muscle. In vertebrates, this process is poorly understood and lacks an in vivo-validated cell surface heterophilic receptor pair that is necessary for fusion. Identification of essential cell surface interactions between fusing cells is an important step in elucidating the molecular mechanism of cellular fusion. We show here that the zebrafish orthologues of JAM-B and JAM-C receptors are essential for fusion of myocyte precursors to form syncytial muscle fibres. Both jamb and jamc are dynamically co-expressed in developing muscles and encode receptors that physically interact. Heritable mutations in either gene prevent myocyte fusion in vivo, resulting in an overabundance of mononuclear, but otherwise overtly normal, functional fast-twitch muscle fibres. Transplantation experiments show that the Jamb and Jamc receptors must interact between neighbouring cells (in trans for fusion to occur. We also show that jamc is ectopically expressed in prdm1a mutant slow muscle precursors, which inappropriately fuse with other myocytes, suggesting that control of myocyte fusion through regulation of jamc expression has important implications for the growth and patterning of muscles. Our discovery of a receptor-ligand pair critical for fusion in vivo has important implications for understanding the molecular mechanisms responsible for myocyte fusion and its regulation in vertebrate myogenesis.

  5. A flight sensory-motor to olfactory processing circuit in the moth Manduca sexta

    Directory of Open Access Journals (Sweden)

    Samual P Bradley

    2016-02-01

    Full Text Available Neural circuits projecting information from motor pathways to sensory pathways are common across sensory domains. These circuits typically modify sensory function as a result of motor pattern activation; this is particularly so in cases where the resultant behavior affects the sensory experience or its processing. However, such circuits have not been observed projecting to an olfactory pathway in any species despite well characterized active sampling behaviors that produce reafferent mechanical stimuli, such as sniffing in mammals and wing beating in the moth Manduca sexta. In this study we characterize a circuit that connects a flight sensory-motor center to an olfactory center in Manduca. This circuit consists of a single pair of histamine immunoreactive (HA-ir neurons that project from the mesothoracic ganglion to innervate a subset of ventral antennal lobe (AL glomeruli. Furthermore, within the AL we show that the Manduca sexta histamine B receptor (MsHisClB is exclusively expressed by a subset of GABAergic and peptidergic LNs, which broadly project to all olfactory glomeruli. Finally, the HA-ir cell pair is present in fifth stage instar larvae; however, the absence of MsHisClB-ir in the larval antennal center (LAC indicates that the circuit is incomplete prior to metamorphosis and importantly prior to the expression of flight behavior. Although the functional consequences of this circuit remain unknown, these results provide the first detailed description of a circuit that interconnects an olfactory system with motor centers driving flight behaviors including odor-guided flight.

  6. Mechanisms of constitutive and ATP-evoked ATP release in neonatal mouse olfactory epithelium

    Directory of Open Access Journals (Sweden)

    Hayoz Sébastien

    2012-05-01

    Full Text Available Abstract Background ATP is an extracellular signaling molecule with many ascribed functions in sensory systems, including the olfactory epithelium. The mechanism(s by which ATP is released in the olfactory epithelium has not been investigated. Quantitative luciferin-luciferase assays were used to monitor ATP release, and confocal imaging of the fluorescent ATP marker quinacrine was used to monitor ATP release via exocytosis in Swiss Webster mouse neonatal olfactory epithelial slices. Results Under control conditions, constitutive release of ATP occurs via exocytosis, hemichannels and ABC transporters and is inhibited by vesicular fusion inhibitor Clostridium difficile toxin A and hemichannel and ABC transporter inhibitor probenecid. Constitutive ATP release is negatively regulated by the ATP breakdown product ADP through activation of P2Y receptors, likely via the cAMP/PKA pathway. In vivo studies indicate that constitutive ATP may play a role in neuronal homeostasis as inhibition of exocytosis inhibited normal proliferation in the OE. ATP-evoked ATP release is also present in mouse neonatal OE, triggered by several ionotropic P2X purinergic receptor agonists (ATP, αβMeATP and Bz-ATP and a G protein-coupled P2Y receptor agonist (UTP. Calcium imaging of P2X2-transfected HEK293 “biosensor” cells confirmed the presence of evoked ATP release. Following purinergic receptor stimulation, ATP is released via calcium-dependent exocytosis, activated P2X1,7 receptors, activated P2X7 receptors that form a complex with pannexin channels, or ABC transporters. The ATP-evoked ATP release is inhibited by the purinergic receptor inhibitor PPADS, Clostridium difficile toxin A and two inhibitors of pannexin channels: probenecid and carbenoxolone. Conclusions The constitutive release of ATP might be involved in normal cell turn-over or modulation of odorant sensitivity in physiological conditions. Given the growth-promoting effects of ATP, ATP-evoked ATP

  7. Glomerular and Mitral-Granule Cell Microcircuits Coordinate Temporal and Spatial Information Processing in the Olfactory Bulb.

    Science.gov (United States)

    Cavarretta, Francesco; Marasco, Addolorata; Hines, Michael L; Shepherd, Gordon M; Migliore, Michele

    2016-01-01

    The olfactory bulb processes inputs from olfactory receptor neurons (ORNs) through two levels: the glomerular layer at the site of input, and the granule cell level at the site of output to the olfactory cortex. The sequence of action of these two levels has not yet been examined. We analyze this issue using a novel computational framework that is scaled up, in three-dimensions (3D), with realistic representations of the interactions between layers, activated by simulated natural odors, and constrained by experimental and theoretical analyses. We suggest that the postulated functions of glomerular circuits have as their primary role transforming a complex and disorganized input into a contrast-enhanced and normalized representation, but cannot provide for synchronization of the distributed glomerular outputs. By contrast, at the granule cell layer, the dendrodendritic interactions mediate temporal decorrelation, which we show is dependent on the preceding contrast enhancement by the glomerular layer. The results provide the first insights into the successive operations in the olfactory bulb, and demonstrate the significance of the modular organization around glomeruli. This layered organization is especially important for natural odor inputs, because they activate many overlapping glomeruli.

  8. Evaluation of the effect of cigarette smoking on the olfactory neuroepithelium of New Zealand white rabbit, using scanning electron microscope.

    Science.gov (United States)

    Iskander, Nagi M; El-Hennawi, Diaa M; Yousef, Tarek F; El-Tabbakh, Mohammed T; Elnahriry, Tarek A

    2017-06-01

    To detect ultra-structural changes of Rabbit's olfactory neuro-epithelium using scanning electron microscope after exposure to cigarette smoking. Sixty six rabbits (Pathogen free New Zealand white rabbits weighing 1-1.5 kg included in the study were randomly assigned into one of three groups: control group did not expose to cigarette smoking, study group 1 was exposed to cigarette smoking for 3 months and study group 2 was exposed to cigarette smoking 3 months and then stopped for 2 months. Olfactory neuro-epithelium from all rabbits were dissected and examined under Philips XL-30 scanning electron microscope. Changes that were found in the rabbits of study group 1 in comparison to control group were loss of microvilli of sustentacular cells (p = 0.016) and decreases in distribution of specialized cilia of olfactory receptor cells (p = 0.046). Also respiratory metaplasia was detected. These changes were reversible in study group 2. Cigarette smoking causes ultra-structural changes in olfactory neuro-epithelium which may explain why smell was affected in cigarette smokers. Most of these changes were reversible after 45 days of cessation of cigarette smoking to the rabbits.

  9. Glomerular and mitral-granule cell microcircuits coordinate temporal and spatial information processing in the olfactory bulb

    Directory of Open Access Journals (Sweden)

    Francesco Cavarretta

    2016-07-01

    Full Text Available The olfactory bulb processes inputs from olfactory receptor neurons (ORNs through two levels: the glomerular layer at the site of input, and the granule cell level at the site of output to the olfactory cortex. The sequence of action of these two levels has not yet been examined. We analyze this issue using a novel computational framework that is scaled up, in three-dimensions (3D, with realistic representations of the interactions between layers, activated by simulated natural odors, and constrained by experimental and theoretical analyses. We suggest that the postulated functions of glomerular circuits have as their primary role transforming a complex and disorganized input into a contrast-enhanced and normalized representation, but cannot provide for synchronization of the distributed glomerular outputs. By contrast, at the granule cell layer, the dendrodendritic interactions mediate temporal decorrelation, which we show is dependent on the preceding contrast enhancement by the glomerular layer. The results provide the first insights into the successive operations in the olfactory bulb, and demonstrate the significance of the modular organization around glomeruli. This layered organization is especially important for natural odor inputs, because they activate many overlapping glomeruli.

  10. Olfactory lateralization in homing pigeons: a GPS study on birds released with unilateral olfactory inputs.

    Science.gov (United States)

    Gagliardo, Anna; Filannino, Caterina; Ioalè, Paolo; Pecchia, Tommaso; Wikelski, Martin; Vallortigara, Giorgio

    2011-02-15

    A large body of evidence has shown that pigeons rely on an olfactory-based navigational map when homing from unfamiliar locations. Previous studies on pigeons released with one nostril occluded highlighted an asymmetry in favour of the right nostril, particularly concerning the initial orientation performance of naïve birds. Nevertheless, all pigeons experiencing only unilateral olfactory input showed impaired homing, regardless of the side of the occluded nostril. So far this phenomenon has been documented only by observing the birds' vanishing bearings. In the present work we recorded the flight tracks of pigeons with previous homing experience equipped with a GPS data logger and released from an unfamiliar location with the right or the left nostril occluded. The analysis of the tracks revealed that the flight path of the birds with the right nostril occluded was more tortuous than that of unmanipulated controls. Moreover, the pigeons smelling with the left nostril interrupted their journey significantly more frequently and displayed more exploratory activity than the control birds, e.g. during flights around a stopover site. These data suggest a more important involvement of the right olfactory system in processing the olfactory information needed for the operation of the navigational map.

  11. Long-term potentiation and olfactory memory formation in the carp (Cyprinus carpio L.) olfactory bulb.

    Science.gov (United States)

    Satou, M; Anzai, S; Huruno, M

    2005-05-01

    Long-term potentiation of synaptic transmission is considered to be an elementary process underlying the cellular mechanism of memory formation. In the present study we aimed to examine whether or not the dendrodendritic mitral-to-granule cell synapses in the carp olfactory bulb show plastic changes after their repeated activation. It was found that: (1) the dendrodendritic mitral-to-granule cell synapses showed three types of plasticity after tetanic electrical stimulation applied to the olfactory tract-long-term potentiation (potentiation lasting >1 h), short-term potentiation (potentiation lasting 1 h) of the odor-evoked bulbar response accompanied the electrically-induced LTP, and; (4) repeated olfactory stimulation enhanced dendrodendritic mitral-to-granule cell transmission. Based on these results, it was proposed that long-term potentiation (as well as olfactory memory) occurs at the dendrodendritic mitral-to-granule cell synapses after strong and long-lasting depolarization of granule cells, which follows repeated and simultaneous synaptic activation of both the peripheral and deep dendrites (or somata).

  12. A second look at the structure of human olfactory memory.

    Science.gov (United States)

    White, Theresa L

    2009-07-01

    How do we remember olfactory information? Is the architecture of human olfactory memory unique compared with that of memory for other types of stimuli? Ten years ago, a review article evaluated these questions, as well as the distinction between long- and short-term olfactory memory, with three lines of evidence: capacity differences, coding differences, and neuropsychological evidence, though serial position effects were also considered. From the data available at the time, the article preliminarily suggested that olfactory memory was a two-component system that was not qualitatively different from memory systems for other types of stimuli. The decade that has elapsed since then has ushered in considerable changes in theories of memory structure and provided huge advances in neuroscience capabilities. Not only have many studies exploring various aspects of olfactory memory been published, but a model of olfactory perception that includes an integral unitary memory system also has been presented. Consequently, the structure of olfactory memory is reevaluated in the light of further information currently available with the same theoretical lines of evidence previously considered. This evaluation finds that the preponderance of evidence suggests that, as in memory for other types of sensory stimuli, the short-term-long-term distinction remains a valuable dissociation for conceptualizing olfactory memory, though perhaps not as architecturally separate systems.

  13. Comparison between olfactory function of pregnant women and non ...

    African Journals Online (AJOL)

    A structured questionnaire was administered to obtain participants' information on socio-demographics, pregnancy history, and ability to perceive smell. They subjectively rated their olfactory function on a visual analogue scale of 0 – 100. Olfactory threshold (OT), discrimination (OD), identification (OI) scores and TDI of both ...

  14. Voltage-Dependent Intrinsic Bursting in Olfactory Bulb Golgi Cells

    Science.gov (United States)

    Pressler, R. Todd; Rozman, Peter A.; Strowbridge, Ben W.

    2013-01-01

    In the mammalian olfactory bulb (OB), local synaptic circuits modulate the evolving pattern of activity in mitral and tufted cells following olfactory sensory stimulation. GABAergic granule cells, the most numerous interneuron subtype in this brain region, have been extensively studied. However, classic studies using Golgi staining methods…

  15. Kappe neurons, a novel population of olfactory sensory neurons.

    Science.gov (United States)

    Ahuja, Gaurav; Bozorg Nia, Shahrzad; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I

    2014-02-10

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons are identified by their Go-like immunoreactivity, and show a distinct spatial distribution within the olfactory epithelium, similar to, but significantly different from that of crypt neurons. Furthermore, kappe neurons project to a single identified target glomerulus within the olfactory bulb, mdg5 of the mediodorsal cluster, whereas crypt neurons are known to project exclusively to the mdg2 glomerulus. Kappe neurons are negative for established markers of ciliated, microvillous and crypt neurons, but appear to have microvilli. Kappe neurons constitute the fourth type of olfactory sensory neurons reported in teleost fishes and their existence suggests that encoding of olfactory stimuli may require a higher complexity than hitherto assumed already in the peripheral olfactory system.

  16. Neural correlates of taste perception in congenital olfactory impairment

    DEFF Research Database (Denmark)

    Gagnon, Léa; Vestergaard, Martin; Madsen, Kristoffer

    2014-01-01

    taste identification accuracy and its neural correlates using functional magnetic resonance imaging (fMRI) in 12 congenitally olfactory impaired individuals and 8 normosmic controls. Results showed that taste identification was worse in congenitally olfactory impaired compared to control subjects. The fMRI...

  17. Vertebrate Embryonic Cleavage Pattern Determination.

    Science.gov (United States)

    Hasley, Andrew; Chavez, Shawn; Danilchik, Michael; Wühr, Martin; Pelegri, Francisco

    2017-01-01

    The pattern of the earliest cell divisions in a vertebrate embryo lays the groundwork for later developmental events such as gastrulation, organogenesis, and overall body plan establishment. Understanding these early cleavage patterns and the mechanisms that create them is thus crucial for the study of vertebrate development. This chapter describes the early cleavage stages for species representing ray-finned fish, amphibians, birds, reptiles, mammals, and proto-vertebrate ascidians and summarizes current understanding of the mechanisms that govern these patterns. The nearly universal influence of cell shape on orientation and positioning of spindles and cleavage furrows and the mechanisms that mediate this influence are discussed. We discuss in particular models of aster and spindle centering and orientation in large embryonic blastomeres that rely on asymmetric internal pulling forces generated by the cleavage furrow for the previous cell cycle. Also explored are mechanisms that integrate cell division given the limited supply of cellular building blocks in the egg and several-fold changes of cell size during early development, as well as cytoskeletal specializations specific to early blastomeres including processes leading to blastomere cohesion. Finally, we discuss evolutionary conclusions beginning to emerge from the contemporary analysis of the phylogenetic distributions of cleavage patterns. In sum, this chapter seeks to summarize our current understanding of vertebrate early embryonic cleavage patterns and their control and evolution.

  18. Learning about Vertebrate Limb Development

    Science.gov (United States)

    Liang, Jennifer O.; Noll, Matthew; Olsen, Shayna

    2014-01-01

    We have developed an upper-level undergraduate laboratory exercise that enables students to replicate a key experiment in developmental biology. In this exercise, students have the opportunity to observe live chick embryos and stain the apical ectodermal ridge, a key tissue required for development of the vertebrate limb. Impressively, every…

  19. Comparative Studies of Vertebrate Platelet Glycoprotein 4 (CD36

    Directory of Open Access Journals (Sweden)

    Roger S. Holmes

    2012-09-01

    Full Text Available Platelet glycoprotein 4 (CD36 (or fatty acyl translocase [FAT], or scavenger receptor class B, member 3 [SCARB3] is an essential cell surface and skeletal muscle outer mitochondrial membrane glycoprotein involved in multiple functions in the body. CD36 serves as a ligand receptor of thrombospondin, long chain fatty acids, oxidized low density lipoproteins (LDLs and malaria-infected erythrocytes. CD36 also influences various diseases, including angiogenesis, thrombosis, atherosclerosis, malaria, diabetes, steatosis, dementia and obesity. Genetic deficiency of this protein results in significant changes in fatty acid and oxidized lipid uptake. Comparative CD36 amino acid sequences and structures and CD36 gene locations were examined using data from several vertebrate genome projects. Vertebrate CD36 sequences shared 53–100% identity as compared with 29–32% sequence identities with other CD36-like superfamily members, SCARB1 and SCARB2. At least eight vertebrate CD36 N-glycosylation sites were conserved which are required for membrane integration. Sequence alignments, key amino acid residues and predicted secondary structures were also studied. Three CD36 domains were identified including cytoplasmic, transmembrane and exoplasmic sequences. Conserved sequences included N- and C-terminal transmembrane glycines; and exoplasmic cysteine disulphide residues; TSP-1 and PE binding sites, Thr92 and His242, respectively; 17 conserved proline and 14 glycine residues, which may participate in forming CD36 ‘short loops’; and basic amino acid residues, and may contribute to fatty acid and thrombospondin binding. Vertebrate CD36 genes usually contained 12 coding exons. The human CD36 gene contained transcription factor binding sites (including PPARG and PPARA contributing to a high gene expression level (6.6 times average. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate CD36 gene with vertebrate

  20. [Microsurgical removal of olfactory groove meningiomas].

    Science.gov (United States)

    Liang, Ri-Sheng; Zhou, Liang-Fu; Mao, Ying; Zhang, Rong; Yang, Wei-Zhong

    2011-01-01

    To explore an effective method for further improving the surgical results of treatment of olfactory groove meningiomas. Sixty seven cases of olfactory groove meningiomas were treated by microneurosurgery, among which fifty seven were de novo cases, eight were recurrent tumors and the other two re-recurrent cases. Modified Derome approach was used in 12 cases, bilateral subfrontal approach in 28 cases, modified pterional approach in 21 cases and unilateral subfrontal approach in six cases. Tumors were resected microsurgically with radical removal of invaded dura, bone, and paranasal sinus mucosa. Reconstruction was performed in patients with skull base defect. Simpson grade I removal was accomplished in 59 cases, grade II in seven cases and grade IV in one case. Among 57 patients with de novo tumor, Simpson I resection was accomplished in 54 cases. Postoperative rhinorrhea and intracranial infection occurred in one case and was cured after temporal lumbar CSF drainage and antibiotic therapy. Two patients (2.9%) died within one month after operation, i.e.one aged patient of heart failure and the other of severe hypothalamus complication. Forty seven patients (72.3%) were followed up from one to ten years with an average of five years and four months. With the exception of two cases died, among the alive 45 patients, there were only three patients with tumor recurrence, which had undergone Simpson II or IV tumor resection. No recurrence was found in cases with Simpson I tumor removal. Previous blurred vision was not improved in three patients, hemiparalysis in two patients, and the other patients recovered well, resuming previous jobs or being able to take care themselves. Total tumor removal (Simpson I) should be the surgical goal for treatment of olfactory groove meningiomas, especially for de novo cases. An appropriate approach is fundamental in the effort to remove an OGM totally. Appropriate anterior skull base reconstruction with vascularized material is

  1. Olfactory stimulation modulates the blood glucose level in rats.

    Science.gov (United States)

    Tsuji, Tadataka; Tanaka, Susumu; Bakhshishayan, Sanam; Kogo, Mikihiko; Yamamoto, Takashi

    2018-01-01

    In both humans and animals, chemosensory stimuli, including odors and tastes, induce a variety of physiologic and mental responses related to energy homeostasis, such as glucose kinetics. The present study examined the importance of olfactory function in glucose kinetics following ingestion behavior in a simplified experimental scenario. We applied a conventional glucose tolerance test to rats with and without olfactory function and analyzed subsequent blood glucose (BG) curves in detail. The loss of olfactory input due to experimental damage to the olfactory mucosa induced a marked decrease in the area under the BG curve. Exposure to grapefruit odor and its main component, limonene, both of which activate the sympathetic nerves, before glucose loading also greatly depressed the BG curve. Pre-loading exposure to lavender odor, a parasympathetic activator, stabilized the BG level. These results suggest that olfactory function is important for proper glucose kinetics after glucose intake and that certain fragrances could be utilized as tools for controlling BG levels.

  2. Evaluation of olfactory function in adults with primary hypothyroidism.

    Science.gov (United States)

    Günbey, Emre; Karlı, Rıfat; Gökosmanoğlu, Feyzi; Düzgün, Berkan; Ayhan, Emre; Atmaca, Hulusi; Ünal, Recep

    2015-10-01

    Sufficient clinical data are not available on the effect of hypothyroidism on olfactory function in adults. In this study, we aimed to evaluate the olfactory function of adult patients diagnosed with primary hypothyroidism. Forty-five patients aged between 18 and 60 years who were diagnosed with clinical primary hypothyroidism and 45 healthy controls who had normal thyroid function tests were included in the study. Sniffin' Sticks olfactory test results of the 2 groups were compared. The relationships between thyroid function tests and olfactory parameters were evaluated. Odor threshold, identification, and discrimination scores of the hypothyroid group were significantly lower than those of the control group (p adults with hypothyroidism. FT3 levels were found to have a more significant relationship with olfactory parameters than TSH or FT4 levels. © 2015 ARS-AAOA, LLC.

  3. Olfactory memory formation in Drosophila: from molecular to systems neuroscience.

    Science.gov (United States)

    Davis, Ronald L

    2005-01-01

    The olfactory nervous system of insects and mammals exhibits many similarities, which suggests that the mechanisms for olfactory learning may be shared. Molecular genetic investigations of Drosophila learning have uncovered numerous genes whose gene products are essential for olfactory memory formation. Recent studies of the products of these genes have continued to expand the range of molecular processes known to underlie memory formation. Recent research has also broadened the neuroanatomical areas thought to mediate olfactory learning to include the antennal lobes in addition to a previously accepted and central role for the mushroom bodies. The roles for neurons extrinsic to the mushroom body neurons are becoming better defined. Finally, the genes identified to participate in Drosophila olfactory learning have conserved roles in mammalian organisms, highlighting the value of Drosophila for gene discovery.

  4. Preservation of olfaction in surgery of olfactory groove meningiomas.

    Science.gov (United States)

    Jang, Woo-Youl; Jung, Shin; Jung, Tae-Young; Moon, Kyung-Sub; Kim, In-Young

    2013-08-01

    Olfaction is commonly considered as secondary among the sensory functions, perhaps reflecting a lack of interest in sparing olfaction after surgery for the olfactory groove meningiomas (OGM). However, considering the repercussions of olfaction for the quality of life, the assessment of post-operative olfaction should be necessary. We retrospectively reviewed the olfactory outcome in patients with OGM and investigated the factors associated with sparing the post-operative olfaction. Between 1993 and 2012, 40 patients with OGM underwent surgical resection and estimated the olfactory function using the Korean version of "Sniffin'Sticks" test (KVSS). Variable factors, such as tumor size, degree of preoperative edema, tumor consistency, preoperative olfactory function, surgical approaches, patient's age, and gender were analyzed with attention to the post-operative olfactory function. Anatomical and functional preservation of olfactory structures were achieved in 26 patients (65%) and 22 patients (55%), respectively. Among the variable factors, size of tumor was significant related to the preservation of post-operative olfaction. (78.6% in size4 cm, p=0.035). Sparing the olfaction was significantly better in patients without preoperative olfactory dysfunction (84.6%) compared with ones with preoperative olfactory dysfunction (40.7%, p=0.016). The frontolateral approach achieved much more excellent post-operative olfactory function (71.4%) than the bifrontal approach (36.8%, p=0.032). If the tumor was smaller than 4 cm and the patients did not present olfactory dysfunction preoperatively, the possibility of sparing the post-operative olfaction was high. Among the variable surgical approaches, frontolateral route may be preferable sparing the post-operative olfaction. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Dopaminergic modulation of mitral cell activity in the frog olfactory bulb: a combined radioligand binding-electrophysiological study

    International Nuclear Information System (INIS)

    Duchamp, A.; Moyse, E.; Delaleu, J.-C.; Coronas, V.; Duchamp-Viret, P.

    1997-01-01

    Dopamine content in the amphibian olfactory bulb is supplied by interneurons scattered among mitral cells in the external plexiform/mitral cell layer. In mammals, dopamine has been found to be involved in various aspects of bulbar information processing by influencing mitral cell odour responsiveness. Dopamine action in the bulb depends directly on the localization of its receptor targets, found to be mainly of the D 2 type in mammals. The present study assessed, in the frog, both the anatomical localization of D 2 -like, radioligand-labelled receptors of dopamine and the in vivo action of dopamine on unitary mitral cell activity in response to odours delivered over a wide range of concentrations. The [ 125 I]iodosulpride-labelled D 2 binding sites were visualized on frozen sagittal sections of frog brains by film radioautography. The sites were found to be restricted to the external plexiform/mitral cell layer; other layers of the olfactory bulb were devoid of specific labelling. Electrophysiological recordings of mitral unit activity revealed that dopamine or its agonist apomorphine induced a drastic reduction of spontaneous firing rate of mitral cells in most cases without altering odour intensity coding properties of these cells. Moreover, pre-treatment with the D 2 antagonist eticlopride blocked the dopamine-induced reduction of mitral cell spontaneous activity.In the frog olfactory bulb, both anatomical localization of D 2 -like receptors and functional data on dopamine involvement in information processing differ from those reported in mammals. This suggests a phylogenetic evolution of dopamine action in the olfactory bulb. In the frog, anatomical data perfectly corroborate electrophysiological results, together strongly suggesting a direct action of dopamine on mitral cells. In a physiologically operating system, such an action would result in a global improvement of signal-to-noise ratio. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights

  6. Constrained vertebrate evolution by pleiotropic genes

    DEFF Research Database (Denmark)

    Hu, Haiyang; Uesaka, Masahiro; Guo, Song

    2017-01-01

    applied to vertebrates than chordates. Furthermore, we found that vertebrates' conserved mid-embryonic developmental programmes are intensively recruited to other developmental processes, and the degree of the recruitment positively correlates with their evolutionary conservation and essentiality...... for normal development. Thus, we propose that the intensively recruited genetic system during vertebrates' organogenesis period imposed constraints on its diversification through pleiotropic constraints, which ultimately led to the common anatomical pattern observed in vertebrates....

  7. Inducible Activation of ERK5 MAP Kinase Enhances Adult Neurogenesis in the Olfactory Bulb and Improves Olfactory Function

    Science.gov (United States)

    Wang, Wenbin; Lu, Song; Li, Tan; Pan, Yung-Wei; Zou, Junhui; Abel, Glen M.; Xu, Lihong; Storm, Daniel R.

    2015-01-01

    Recent discoveries have suggested that adult neurogenesis in the subventricular zone (SVZ) and olfactory bulb (OB) may be required for at least some forms of olfactory behavior in mice. However, it is unclear whether conditional and selective enhancement of adult neurogenesis by genetic approaches is sufficient to improve olfactory function under physiological conditions or after injury. Furthermore, specific signaling mechanisms regulating adult neurogenesis in the SVZ/OB are not fully defined. We previously reported that ERK5, a MAP kinase selectively expressed in the neurogenic regions of the adult brain, plays a critical role in adult neurogenesis in the SVZ/OB. Using a site-specific knock-in mouse model, we report here that inducible and targeted activation of the endogenous ERK5 in adult neural stem/progenitor cells enhances adult neurogenesis in the OB by increasing cell survival and neuronal differentiation. This conditional ERK5 activation also improves short-term olfactory memory and odor-cued associative olfactory learning under normal physiological conditions. Furthermore, these mice show enhanced recovery of olfactory function and have more adult-born neurons after a zinc sulfate-induced lesion of the main olfactory epithelium. We conclude that ERK5 MAP kinase is an important endogenous signaling pathway regulating adult neurogenesis in the SVZ/OB, and that conditional activation of endogenous ERK5 is sufficient to enhance adult neurogenesis in the OB thereby improving olfactory function both under normal conditions and after injury. PMID:25995470

  8. Measurement and Analysis of Olfactory Responses with the Aim of Establishing an Objective Diagnostic Method for Central Olfactory Disorders

    Science.gov (United States)

    Uno, Tominori; Wang, Li-Qun; Miwakeichi, Fumikazu; Tonoike, Mitsuo; Kaneda, Teruo

    In order to establish a new diagnostic method for central olfactory disorders and to identify objective indicators, we measured and analyzed brain activities in the parahippocampal gyrus and uncus, region of responsibility for central olfactory disorders. The relationship between olfactory stimulation and brain response at region of responsibility can be examined in terms of fitted responses (FR). FR in these regions may be individual indicators of changes in brain olfactory responses. In the present study, in order to non-invasively and objectively measure olfactory responses, an odor oddball task was conducted on four healthy volunteers using functional magnetic resonance imaging (fMRI) and a odorant stimulator with blast-method. The results showed favorable FR and activation in the parahippocampal gyrus or uncus in all subjects. In some subjects, both the parahippocampal gyrus and uncus were activated. Furthermore, activation was also confirmed in the cingulate gyrus, middle frontal gyrus, precentral gyrus, postcentral gyrus, superior temporal gyrus and insula. The hippocampus and uncus are known to be involved in the olfactory disorders associated with early-stage Alzheimer's disease and other olfactory disorders. In the future, it will be necessary to further develop the present measurement and analysis method to clarify the relationship between central olfactory disorders and brain activities and establish objective indicators that are useful for diagnosis.

  9. An invertebrate stomach's view on vertebrate ecology

    DEFF Research Database (Denmark)

    Calvignac-Spencer, Sébastien; Leendertz, Fabian H.; Gilbert, Tom

    2013-01-01

    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population...

  10. The mechanoreceptors of the costo-vertebral joints

    Science.gov (United States)

    Godwin-Austen, R. B.

    1969-01-01

    1. Unitary recording in the thoracic dorsal roots of mechanoreceptor discharges from the costo-vertebral joints was carried out in the cat and rabbit. Criteria for the identification of costo-vertebral joint mechanoreceptors were established. 2. The majority of rib joint mechanoreceptors are slowly adapting and fifty-three such receptors were studied. Five rapidly adapting receptors were also identified. 3. The responses of these receptors have been correlated with rib position and movement. The slowly adapting receptors gave a monotonic response to different rib positions. 72% showed an increase of discharge rate with displacements towards expiratory rib positions. 4. In response to manually imposed rib movements slowly adapting joint mechanoreceptors gave a dynamic response which was directly related to the velocity of the movement and adapted within 2 sec. The movements of breathing produced a corresponding alteration of the discharge frequency of the slowly adapting receptors. 5. Slowly adapting receptors were localized to the capsule of the costo-transverse joint by probing. They responded to increased intra-articular pressure with an increase of discharge rate and were silenced by intra-articular lignocaine, 0·4%. 6. Rapidly adapting joint mechanoreceptors responded to rib movement with a brief burst of discharges. 7. The rib joint mechanoreceptors signal rib joint position, and the direction and velocity of rib movement. It is suggested that these afferent discharges provide the basis for the perception of respiratory movements of the chest. The significance of these receptors to the `sense of effort' resulting from a resistance to breathing is discussed. PMID:5789947

  11. From antenna to antenna: lateral shift of olfactory memory recall by honeybees.

    Science.gov (United States)

    Rogers, Lesley J; Vallortigara, Giorgio

    2008-06-04

    Honeybees, Apis mellifera, readily learn to associate odours with sugar rewards and we show here that recall of the olfactory memory, as demonstrated by the bee extending its proboscis when presented with the trained odour, involves first the right and then the left antenna. At 1-2 hour after training using both antennae, recall is possible mainly when the bee uses its right antenna but by 6 hours after training a lateral shift has occurred and the memory can now be recalled mainly when the left antenna is in use. Long-term memory one day after training is also accessed mainly via the left antenna. This time-dependent shift from right to left antenna is also seen as side biases in responding to odour presented to the bee's left or right side. Hence, not only are the cellular events of memory formation similar in bees and vertebrate species but also the lateralized networks involved may be similar. These findings therefore seem to call for remarkable parallel evolution and suggest that the proper functioning of memory formation in a bilateral animal, either vertebrate or invertebrate, requires lateralization of processing.

  12. From antenna to antenna: lateral shift of olfactory memory recall by honeybees.

    Directory of Open Access Journals (Sweden)

    Lesley J Rogers

    Full Text Available Honeybees, Apis mellifera, readily learn to associate odours with sugar rewards and we show here that recall of the olfactory memory, as demonstrated by the bee extending its proboscis when presented with the trained odour, involves first the right and then the left antenna. At 1-2 hour after training using both antennae, recall is possible mainly when the bee uses its right antenna but by 6 hours after training a lateral shift has occurred and the memory can now be recalled mainly when the left antenna is in use. Long-term memory one day after training is also accessed mainly via the left antenna. This time-dependent shift from right to left antenna is also seen as side biases in responding to odour presented to the bee's left or right side. Hence, not only are the cellular events of memory formation similar in bees and vertebrate species but also the lateralized networks involved may be similar. These findings therefore seem to call for remarkable parallel evolution and suggest that the proper functioning of memory formation in a bilateral animal, either vertebrate or invertebrate, requires lateralization of processing.

  13. A physiological increase of insulin in the olfactory bulb decreases detection of a learned aversive odor and abolishes food odor-induced sniffing behavior in rats.

    Directory of Open Access Journals (Sweden)

    Pascaline Aimé

    Full Text Available Insulin is involved in multiple regulatory mechanisms, including body weight and food intake, and plays a critical role in metabolic disorders such as obesity and diabetes. An increasing body of evidence indicates that insulin is also involved in the modulation of olfactory function. The olfactory bulb (OB contains the highest level of insulin and insulin receptors (IRs in the brain. However, a role for insulin in odor detection and sniffing behavior remains to be elucidated. Using a behavioral paradigm based on conditioned olfactory aversion (COA to isoamyl-acetate odor, we demonstrated that an intracerebroventricular (ICV injection of 14 mU insulin acutely decreased olfactory detection of fasted rats to the level observed in satiated animals. In addition, whereas fasted animals demonstrated an increase in respiratory frequency upon food odor detection, this effect was absent in fasted animals receiving a 14 mU insulin ICV injection as well as in satiated animals. In parallel, we showed that the OB and plasma insulin levels were increased in satiated rats compared to fasted rats, and that a 14 mU insulin ICV injection elevated the OB insulin level of fasted rats to that of satiated rats. We further quantified insulin receptors (IRs distribution and showed that IRs are preferentially expressed in the caudal and lateral parts of the main OB, with the highest labeling found in the mitral cells, the main OB projection neurons. Together, these data suggest that insulin acts on the OB network to modulate olfactory processing and demonstrate that olfactory function is under the control of signals involved in energy homeostasis regulation and feeding behaviors.

  14. Multiple reversal olfactory learning in honeybees

    Directory of Open Access Journals (Sweden)

    Theo Mota

    2010-07-01

    Full Text Available In multiple reversal learning, animals trained to discriminate a reinforced from a non-reinforced stimulus are subjected to various, successive reversals of stimulus contingencies (e.g. A+ vs. B-, A- vs. B+, A+ vs. B-. This protocol is useful to determine whether or not animals learn to learn and solve successive discriminations faster (or with fewer errors with increasing reversal experience. Here we used the olfactory conditioning of proboscis extension reflex to study how honeybees Apis mellifera perform in a multiple reversal task. Our experiment contemplated four consecutive differential conditioning phases involving the same odors (A+ vs. B- to A- vs. B+ to A+ vs. B- to A- vs. B+. We show that bees in which the weight of reinforced or non-reinforced stimuli was similar mastered the multiple olfactory reversals. Bees which failed the task exhibited asymmetric responses to reinforced and non-reinforced stimuli, thus being unable to rapidly reverse stimulus contingencies. Efficient reversers did not improve their successive discriminations but rather tended to generalize their choice to both odors at the end of conditioning. As a consequence, both discrimination and reversal efficiency decreasedalong experimental phases. This result invalidates a learning-to-learn effect and indicates that bees do not only respond to the actual stimulus contingencies but rather combine these with an average of past experiences with the same stimuli.  

  15. [Is olfactory function impaired in moderate height?].

    Science.gov (United States)

    Kühn, M; Welsch, H; Zahnert, T; Hummel, Thomas

    2009-09-01

    The human sense of smell seems to be influenced by the surrounding barometric pressure. These factors appear to be especially important during flights, for example, in order to recognize the smell of fire etc. Thus, questions are whether pilots or passengers exhibit an impaired smell sensitivity when tested at moderate heights, or, whether changes in humidity would affect the sense of smell. Using climate chambers, odor discrimination and butanol odor thresholds were tested in 77 healthy normosmic volunteers (5 female, 72 male; aged 25+/-8 years from 18 up to 53 years) under hypobaric (2 700+/-20 m, 20 degrees C+/-1 K, rh=50+/-5%) and hyperbaric, (10+/-0.5 m (2 bar)) and different humidity conditions (30 vs. 80%, 20 degrees C+/-1 K, normobaric). During all conditions cognitive performance was tested. Among other effects, olfactory sensitivity was impaired at threshold, but not suprathreshold level, in a hypobaric compared to a hyperbaric milieu, and thresholds were lower in humid, compared to relatively dry conditions. In conclusion, environmental conditions modulate the sense of smell, and may, consecutively, influence results from olfactory tests. During flight hypobaric conditions, mild hypoxia and dry air may cause impaired sensitivity of smell. Georg Thieme Verlag KG Stuttgart * New York.

  16. Quantitative autoradiographic mapping of serotonin receptors in the rat brain. II. Serotonin-2 receptors

    International Nuclear Information System (INIS)

    Pazos, A.; Cortes, R.; Palacios, J.M.

    1985-01-01

    The distribution of serotonin-2 (5-HT 2 ) receptors in the rat brain was studied by light microscopic quantitative autoradiography. Receptors were labeled with four ligands: [ 3 H]ketanserin, [ 3 H]mesulergine, [ 3 H]LSD and [ 3 H]spiperone, which are reported to show high affinity for 5-HT 2 receptors. Very high concentrations were localized in the claustrum, olfactory tubercle and layer IV of the neocortex. The anterior olfactory nucleus, piriform cortex and layer I of neocortex were also rich in 5-HT 2 receptors. The specificity of the different ligands used is discussed in terms of the other populations of sites recognized by them. The distribution of 5-HT 2 receptors here reported is discussed in correlation with (a) the known distribution of serotoninergic terminals, (b) the specific anatomical systems and (c) the central effects reported to be mediated by 5-HT 2 -selective drugs. (Auth.)

  17. Molecular Evolution and Functional Divergence of Trace Amine-Associated Receptors.

    Directory of Open Access Journals (Sweden)

    Seong-Il Eyun

    Full Text Available Trace amine-associated receptors (TAARs are a member of the G-protein-coupled receptor superfamily and are known to be expressed in olfactory sensory neurons. A limited number of molecular evolutionary studies have been done for TAARs so far. To elucidate how lineage-specific evolution contributed to their functional divergence, we examined 30 metazoan genomes. In total, 493 TAAR gene candidates (including 84 pseudogenes were identified from 26 vertebrate genomes. TAARs were not identified from non-vertebrate genomes. An ancestral-type TAAR-like gene appeared to have emerged in lamprey. We found four therian-specific TAAR subfamilies (one eutherian-specific and three metatherian-specific in addition to previously known nine subfamilies. Many species-specific TAAR gene duplications and losses contributed to a large variation of TAAR gene numbers among mammals, ranging from 0 in dolphin to 26 in flying fox. TAARs are classified into two groups based on binding preferences for primary or tertiary amines as well as their sequence similarities. Primary amine-detecting TAARs (TAAR1-4 have emerged earlier, generally have single-copy orthologs (very few duplication or loss, and have evolved under strong functional constraints. In contrast, tertiary amine-detecting TAARs (TAAR5-9 have emerged more recently and the majority of them experienced higher rates of gene duplications. Protein members that belong to the tertiary amine-detecting TAAR group also showed the patterns of positive selection especially in the area surrounding the ligand-binding pocket, which could have affected ligand-binding activities and specificities. Expansions of the tertiary amine-detecting TAAR gene family may have played important roles in terrestrial adaptations of therian mammals. Molecular evolution of the TAAR gene family appears to be governed by a complex, species-specific, interplay between environmental and evolutionary factors.

  18. Processing of Intraoral Olfactory and Gustatory Signals in the Gustatory Cortex of Awake Rats.

    Science.gov (United States)

    Samuelsen, Chad L; Fontanini, Alfredo

    2017-01-11

    The integration of gustatory and olfactory information is essential to the perception of flavor. Human neuroimaging experiments have pointed to the gustatory cortex (GC) as one of the areas involved in mediating flavor perception. Although GC's involvement in encoding the chemical identity and hedonic value of taste stimuli is well studied, it is unknown how single GC neurons process olfactory stimuli emanating from the mouth. In this study, we relied on multielectrode recordings to investigate how single GC neurons respond to intraorally delivered tastants and tasteless odorants dissolved in water and whether/how these two modalities converge in the same neurons. We found that GC neurons could either be unimodal, responding exclusively to taste (taste-only) or odor (odor-only), or bimodal, responding to both gustatory and olfactory stimuli. Odor responses were confirmed to result from retronasal olfaction: monitoring respiration revealed that exhalation preceded odor-evoked activity and reversible inactivation of olfactory receptors in the nasal epithelium significantly reduced responses to intraoral odorants but not to tastants. Analysis of bimodal neurons revealed that they encode palatability significantly better than the unimodal taste-only group. Bimodal neurons exhibited similar responses to palatable tastants and odorants dissolved in water. This result suggested that odorized water could be palatable. This interpretation was further supported with a brief access task, where rats avoided consuming aversive taste stimuli and consumed the palatable tastants and dissolved odorants. These results demonstrate the convergence of the chemosensory components of flavor onto single GC neurons and provide evidence for the integration of flavor with palatability coding. Food perception and choice depend upon the concurrent processing of olfactory and gustatory signals from the mouth. The primary gustatory cortex has been proposed to integrate chemosensory stimuli

  19. Zygotic Genome Activation in Vertebrates.

    Science.gov (United States)

    Jukam, David; Shariati, S Ali M; Skotheim, Jan M

    2017-08-21

    The first major developmental transition in vertebrate embryos is the maternal-to-zygotic transition (MZT) when maternal mRNAs are degraded and zygotic transcription begins. During the MZT, the embryo takes charge of gene expression to control cell differentiation and further development. This spectacular organismal transition requires nuclear reprogramming and the initiation of RNAPII at thousands of promoters. Zygotic genome activation (ZGA) is mechanistically coordinated with other embryonic events, including changes in the cell cycle, chromatin state, and nuclear-to-cytoplasmic component ratios. Here, we review progress in understanding vertebrate ZGA dynamics in frogs, fish, mice, and humans to explore differences and emphasize common features. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Unique in vivo properties of olfactory ensheathing cells that may contribute to neural repair and protection following spinal cord injury

    Science.gov (United States)

    Kocsis, Jeffery D.; Lankford, Karen L.; Sasaki, Masanori; Radtke, Christine

    2009-01-01

    Olfactory ensheathing cells (OECs) are specialized glial cells that guide olfactory receptor axons from the nasal mucosa into the brain where they make synaptic contacts in the olfactory bulb. While a number of studies have demonstrated that in vivo transplantation of OECs into injured spinal cord results in improved functional outcome, precise cellular mechanisms underlying this improvement are not fully understood. Current thinking is that OECs can encourage axonal regeneration, provide trophic support for injured neurons and for angiogenesis, and remyelinate axons. However, Schwann cell (SC) transplantation also results in significant functional improvement in animal models of spinal cord injury. In culture SCs and OECs share a number of phenotypic properties such as expression of the low affinity NGF receptor (p75). An important area of research has been to distinguish potential differences in the in vivo behavior of OECs and SCs to determine if one cell type may offer greater advantage as a cellular therapeutic candidate. In this review we focus on several unique features of OECs when they are transplanted into the spinal cord. PMID:19429149

  1. The origin of vertebrate limbs.

    Science.gov (United States)

    Coates, M I

    1994-01-01

    The earliest tetrapod limbs are polydactylous, morphologically varied and do not conform to an archetypal pattern. These discoveries, combined with the unravelling of limb developmental morphogenetic and regulatory mechanisms, have prompted a re-examination of vertebrate limb evolution. The rich fossil record of vertebrate fins/limbs, although restricted to skeletal tissues, exceeds the morphological diversity of the extant biota, and a systematic approach to limb evolution produces an informative picture of evolutionary change. A composite framework of several phylogenetic hypotheses is presented incorporating living and fossil taxa, including the first report of an acanthodian metapterygium and a new reconstruction of the axial skeleton and caudal fin of Acanthostega gunnari. Although significant nodes in vertebrate phylogeny remain poorly resolved, clear patterns of morphogenetic evolution emerge: median fin origination and elaboration initially precedes that of paired fins; pectoral fins initially precede pelvic fin development; evolving patterns of fin distribution, skeletal tissue diversity and structural complexity become decoupled with increased taxonomic divergence. Transformational sequences apparent from the fish-tetrapod transition are reiterated among extant lungfishes, indicating further directions for comparative experimental research. The evolutionary diversification of vertebrate fin and limb patterns challenges a simple linkage between Hox gene conservation, expression and morphology. A phylogenetic framework is necessary in order to distinguish shared from derived characters in experimental model regulatory systems. Hox and related genomic evolution may include convergent patterns underlying functional and morphological diversification. Brachydanio is suggested as an example where tail-drive patterning demands may have converged with the regulation of highly differentiated limbs in tetrapods.

  2. Neurobiology of mammalian olfactory learning that occurs during sensitive periods

    Directory of Open Access Journals (Sweden)

    Hideto KABA

    2010-12-01

    Full Text Available This review examines the organizational principles underlying olfactory learning in three specialized contexts that occur during sensitive periods of enhanced neural plasticity and emphasizes some of their common features. All three forms of olfactory learning are associated with neural changes in the olfactory bulb (OB at the first stage of sensory processing. These changes require the association of the olfactory and somatosensory signals in the OB. They all depend on somatosensory stimulation-induced release of noradrenaline that induces structural and functional changes at mitral-granule cell reciprocal synapses in the OB, resulting in increases in inhibitory transmission. In the accessory olfactory bulb, this represents the enhanced self-inhibition of mitral cells, which selectively disrupts the transmission of the mating male’s pregnancy-blocking signal at this level. In contrast, an extensive network of secondary dendrites of mitral cells in the main olfactory bulb probably results in a sharpening of the odor-induced pattern of activity, due to increases in lateral inhibition, leading to offspring recognition in sheep and neonatal learning in rats and rabbits. These findings show that inhibitory interneurons play a critical role in olfactory learning. Further work on how these neurons shape olfactory circuit function could provide important clues to understand memory functions of interneurons in other systems. Moreover, recent research has suggested that three forms of olfactory learning are controlled by synergistic, redundant, and distributed neural mechanisms. This has general implications regarding the mechanisms that may contribute to the robustness of memories [Current Zoology 56 (6: 819–833, 2010].

  3. Gender-typical olfactory regulation of sexual behavior in goldfish

    Directory of Open Access Journals (Sweden)

    Makito eKobayashi

    2014-04-01

    Full Text Available It is known that olfaction is essential for the occurrence of sexual behavior in male goldfish. Sex pheromones from ovulatory females elicit male sexual behavior, chasing and sperm releasing act. In female goldfish, ovarian prostaglandin F2α (PGF elicits female sexual behavior, egg releasing act. It has been considered that olfaction does not affect sexual behavior in female goldfish. In the present study, we reexamined the involvement of olfaction in sexual behavior of female goldfish. Olfaction was blocked in male and female goldfish by two methods: nasal occlusion (NO which blocks the reception of olfactants, and olfactory tract section (OTX which blocks transmission of olfactory information from the olfactory bulb to the telencephalon. Sexual behavior of goldfish was induced by administration of PGF to females, an established method for inducing goldfish sexual behavior in both sexes. Sexual behavior in males was suppressed by NO and OTX as previously reported because of lack of pheromone stimulation. In females, NO suppressed sexual behavior but OTX did not affect the occurrence of sexual behavior. Females treated with both NO and OTX performed sexual behavior normally. These results indicate that olfaction is essential in female goldfish to perform sexual behavior as in males but in a different manner. The lack of olfaction in males causes lack of pheromonal stimulation, resulting in no behavior elicited. Whereas the results of female experiments suggest that lack of olfaction in females causes strong inhibition of sexual behavior mediated by the olfactory pathway. Olfactory tract section is considered to block the pathway and remove this inhibition, resulting in the resumption of the behavior. By subtract sectioning of the olfactory tract, it was found that this inhibition was mediated by the medial olfactory tracts, not the lateral olfactory tracts. Thus, it is concluded that goldfish has gender-typical olfactory regulation for sexual

  4. Face detection for interactive tabletop viewscreen system using olfactory display

    Science.gov (United States)

    Sakamoto, Kunio; Kanazawa, Fumihiro

    2009-10-01

    An olfactory display is a device that delivers smells to the nose. It provides us with special effects, for example to emit smell as if you were there or to give a trigger for reminding us of memories. The authors have developed a tabletop display system connected with the olfactory display. For delivering a flavor to user's nose, the system needs to recognition and measure positions of user's face and nose. In this paper, the authors describe an olfactory display which enables to detect the nose position for an effective delivery.

  5. Neural correlates of olfactory processing in congenital blindness

    DEFF Research Database (Denmark)

    Kupers, R; Beaulieu-Lefebvre, M; Schneider, F C

    2011-01-01

    Adaptive neuroplastic changes have been well documented in congenitally blind individuals for the processing of tactile and auditory information. By contrast, very few studies have investigated olfactory processing in the absence of vision. There is ample evidence that the olfactory system...... magnetic resonance imaging to measure changes in the blood-oxygenation level-dependent signal in congenitally blind and blindfolded sighted control subjects during a simple odor detection task. We found several group differences in task-related activations. Compared to sighted controls, congenitally blind......, linking it also to olfactory processing in addition to tactile and auditory processing....

  6. Changes of pressure and humidity affect olfactory function.

    Science.gov (United States)

    Kuehn, Michael; Welsch, Heiko; Zahnert, Thomas; Hummel, Thomas

    2008-03-01

    The present study aimed at investigating the question whether olfactory function changes in relation to barometric pressure and humidity. Using climate chambers, odor threshold and discrimination for butanol were tested in 75 healthy volunteers under hypobaric and hyperbaric, and different humidity conditions. Among other effects, olfactory sensitivity at threshold level, but not suprathreshold odor discrimination, was impaired in a hypobaric compared to a hyperbaric milieu, and thresholds were lower in humid, compared to relatively dry conditions. In conclusion, environmental conditions modulate the sense of smell, and may, consecutively, influence results from olfactory tests.

  7. The olfactory gonadotropin-releasing hormone immunoreactive system in mouse.

    Science.gov (United States)

    Jennes, L

    1986-10-29

    The olfactory gonadotropin-releasing hormone (GnRH) system in mice was studied with immunofluorescence in combination with lesions of the olfactory bulb and retrograde transport of horseradish peroxidase (HRP) which was administered intravascularly, intranasally or into the subarachnoid space. GnRH-positive neurons were located in the two major branches forming the septal roots of the nervus terminalis, in the ganglion terminale, within the fascicles of the nervus terminalis throughout its extent, in a conspicuous band which connects the ventral neck of the caudal olfactory bulb with the accessory olfactory bulb and in the nasal mucosa. GnRH-positive fibers were seen in all areas in which neurons were found, i.e. in the rostral septum, the ganglion and nervus terminalis and in the nasal subepithelium. In addition, a broad bundle of fibers was observed to surround the entire caudal olfactory bulb, connecting the rostral sulcus rhinalis with the ventrocaudal olfactory bulb. Fibers were seen in close association with the main and accessory olfactory bulb, with the fila olfactoria and with the nasal mucosa. Throughout the olfactory bulb and the nasal epithelium, an association of GnRH fibers with blood vessels was apparent. Intravascular and intranasal injection of HRP resulted in labeling of certain GnRH neurons in the septal roots of the nervus terminalis, the ganglion terminale, the nervus terminalis, the caudal ventrodorsal connection and in the accessory olfactory bulb. After placement of HRP into the subarachnoid space dorsal to the accessory olfactory bulb, about 50% of the GnRH neurons in the accessory olfactory bulb and in the ventrodorsal connection were labeled with HRP. Also, a few GnRH neurons in the rostral septum, the ganglion terminale and in the fascicles of the nervus terminalis had taken up the enzyme. Lesions of the nervus terminalis caudal to the ganglion terminale resulted in sprouting of GnRH fibers at both sites of the knife cut. Lesions rostral

  8. Multiple Signaling Pathways Coordinately Regulate Forgetting of Olfactory Adaptation through Control of Sensory Responses in Caenorhabditis elegans.

    Science.gov (United States)

    Kitazono, Tomohiro; Hara-Kuge, Sayuri; Matsuda, Osamu; Inoue, Akitoshi; Fujiwara, Manabi; Ishihara, Takeshi

    2017-10-18

    Forgetting memories is important for animals to properly respond to continuously changing environments. To elucidate the mechanisms of forgetting, we used one of the behavioral plasticities of Caenorhabditis elegans hermaphrodite, olfactory adaptation to an attractive odorant, diacetyl, as a simple model of learning. In C. elegans, the TIR-1/JNK-1 pathway accelerates forgetting of olfactory adaptation by facilitating neural secretion from AWC sensory neurons. In this study, to identify the downstream effectors of the TIR-1/JNK-1 pathway, we conducted a genetic screen for suppressors of the gain-of-function mutant of tir-1 ( ok1052 ), which shows excessive forgetting. Our screening showed that three proteins-a membrane protein, MACO-1; a receptor tyrosine kinase, SCD-2; and its putative ligand, HEN-1-regulated forgetting downstream of the TIR-1/JNK-1 pathway. We further demonstrated that MACO-1 and SCD-2/HEN-1 functioned in parallel genetic pathways, and only MACO-1 regulated forgetting of olfactory adaptation to isoamyl alcohol, which is an attractive odorant sensed by different types of sensory neurons. In olfactory adaptation, odor-evoked Ca 2+ responses in olfactory neurons are attenuated by conditioning and recovered thereafter. A Ca 2+ imaging study revealed that this attenuation is sustained longer in maco-1 and scd-2 mutant animals than in wild-type animals like the TIR-1/JNK-1 pathway mutants. Furthermore, temporal silencing by histamine-gated chloride channels revealed that the neuronal activity of AWC neurons after conditioning is important for proper forgetting. We propose that distinct signaling pathways, each of which has a specific function, may coordinately and temporally regulate forgetting by controlling sensory responses. SIGNIFICANCE STATEMENT Active forgetting is an important process to understand the whole mechanisms of memories. Recent papers have reported that the noncell autonomous regulations are required for proper forgetting in

  9. A spiking neural network model of self-organized pattern recognition in the early mammalian olfactory system

    Science.gov (United States)

    Kaplan, Bernhard A.; Lansner, Anders

    2014-01-01

    Olfactory sensory information passes through several processing stages before an odor percept emerges. The question how the olfactory system learns to create odor representations linking those different levels and how it learns to connect and discriminate between them is largely unresolved. We present a large-scale network model with single and multi-compartmental Hodgkin–Huxley type model neurons representing olfactory receptor neurons (ORNs) in the epithelium, periglomerular cells, mitral/tufted cells and granule cells in the olfactory bulb (OB), and three types of cortical cells in the piriform cortex (PC). Odor patterns are calculated based on affinities between ORNs and odor stimuli derived from physico-chemical descriptors of behaviorally relevant real-world odorants. The properties of ORNs were tuned to show saturated response curves with increasing concentration as seen in experiments. On the level of the OB we explored the possibility of using a fuzzy concentration interval code, which was implemented through dendro-dendritic inhibition leading to winner-take-all like dynamics between mitral/tufted cells belonging to the same glomerulus. The connectivity from mitral/tufted cells to PC neurons was self-organized from a mutual information measure and by using a competitive Hebbian–Bayesian learning algorithm based on the response patterns of mitral/tufted cells to different odors yielding a distributed feed-forward projection to the PC. The PC was implemented as a modular attractor network with a recurrent connectivity that was likewise organized through Hebbian–Bayesian learning. We demonstrate the functionality of the model in a one-sniff-learning and recognition task on a set of 50 odorants. Furthermore, we study its robustness against noise on the receptor level and its ability to perform concentration invariant odor recognition. Moreover, we investigate the pattern completion capabilities of the system and rivalry dynamics for odor mixtures. PMID

  10. Olfactory groove meningiomas: approaches and complications.

    Science.gov (United States)

    Aguiar, Paulo Henrique Pires de; Tahara, Adriana; Almeida, Antonio Nogueira; Simm, Renata; Silva, Arnaldo Neves da; Maldaun, Marcos Vinicius Calfatt; Panagopoulos, Alexandros Theodoros; Zicarelli, Carlos Alexandre; Silva, Pedro Gabriel

    2009-09-01

    Olfactory groove meningiomas (OGM) account for 4.5% of all intracranial meningiomas. We report 21 patients with OGMs. Tumors were operated on using three surgical approaches: bifrontal (7 patients), fronto-pterional (11 patients) and fronto-orbital (3 patients). Total tumor removal (Simpson Grade 1) was achieved in 13 patients and Simpson II in 8 patients. Perioperative mortality was 4.76%. The average size of the OGM was 4.3+/-1.1cm. The overall recurrence rate was 19%. We preferred to use the pterional approach, which provides quick access to the tumor with less brain exposure. It also allows complete drainage of cisternal cerebrospinal fluid, providing a good level of brain relaxation during surgery. However, for long, thin tumors, hemostasis can be difficult using this approach.

  11. Fault tolerant architecture for artificial olfactory system

    International Nuclear Information System (INIS)

    Lotfivand, Nasser; Hamidon, Mohd Nizar; Abdolzadeh, Vida

    2015-01-01

    In this paper, to cover and mask the faults that occur in the sensing unit of an artificial olfactory system, a novel architecture is offered. The proposed architecture is able to tolerate failures in the sensors of the array and the faults that occur are masked. The proposed architecture for extracting the correct results from the output of the sensors can provide the quality of service for generated data from the sensor array. The results of various evaluations and analysis proved that the proposed architecture has acceptable performance in comparison with the classic form of the sensor array in gas identification. According to the results, achieving a high odor discrimination based on the suggested architecture is possible. (paper)

  12. Proton-Beam Therapy for Olfactory Neuroblastoma

    International Nuclear Information System (INIS)

    Nishimura, Hideki; Ogino, Takashi; Kawashima, Mitsuhiko; Nihei, Keiji; Arahira, Satoko; Onozawa, Masakatsu; Katsuta, Shoichi; Nishio, Teiji

    2007-01-01

    Purpose: To analyze the feasibility and efficacy of proton-beam therapy (PBT) for olfactory neuroblastoma (ONB) as a definitive treatment, by reviewing our preliminary experience. Olfactory neuroblastoma is a rare disease, and a standard treatment strategy has not been established. Radiation therapy for ONB is challenging because of the proximity of ONBs to critical organs. Proton-beam therapy can provide better dose distribution compared with X-ray irradiation because of its physical characteristics, and is deemed to be a feasible treatment modality. Methods and Materials: A retrospective review was performed on 14 patients who underwent PBT for ONB as definitive treatment at the National Cancer Center Hospital East (Kashiwa, Chiba, Japan) from November 1999 to February 2005. A total dose of PBT was 65 cobalt Gray equivalents (Gy E ), with 2.5-Gy E once-daily fractionations. Results: The median follow-up period for surviving patients was 40 months. One patient died from disseminated disease. There were two persistent diseases, one of which was successfully salvaged with surgery. The 5-year overall survival rate was 93%, the 5-year local progression-free survival rate was 84%, and the 5-year relapse-free survival rate was 71%. Liquorrhea was observed in one patient with Kadish's stage C disease (widely destroying the skull base). Most patients experienced Grade 1 to 2 dermatitis in the acute phase. No other adverse events of Grade 3 or greater were observed according to the RTOG/EORTC acute and late morbidity scoring system. Conclusions: Our preliminary results of PBT for ONB achieved excellent local control and survival outcomes without serious adverse effects. Proton-beam therapy is considered a safe and effective modality that warrants further study

  13. A specialized odor memory buffer in primary olfactory cortex.

    Science.gov (United States)

    Zelano, Christina; Montag, Jessica; Khan, Rehan; Sobel, Noam

    2009-01-01

    The neural substrates of olfactory working memory are unknown. We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes. We used functional magnetic resonance imaging to measure activity in the brains of subjects who were remembering either nameable or unnameable odorants. We found a double dissociation whereby remembering nameable odorants was reflected in sustained activity in prefrontal language areas, and remembering unnameable odorants was reflected in sustained activity in primary olfactory cortex. These findings suggest a novel dedicated mechanism in primary olfactory cortex, where odor information is maintained in temporary storage to subserve ongoing tasks.

  14. Surgical Management of Olfactory Groove Meningiomas | El-Naggar ...

    African Journals Online (AJOL)

    Objective: To study the bifrontal approach to olfactory groove meningiomas ... in all patients was Grade I meningiomas (World Health Organization grading). ... Bifrontal approach offers excellent exposure, and when combined with modern ...

  15. Hydrodynamic Interactions Between Olfactory Appendages and Odor Plumes

    National Research Council Canada - National Science Library

    Koseff, Jeffrey

    2000-01-01

    .... A model lobster was then placed in the laboratory flume and we measured the odor concentration distribution around the olfactory appendage using high-speed video and laser-induced fluorescence techniques...

  16. Characterization and visualization of cholecystokinin receptors in rat brain using [3H]pentagastrin

    International Nuclear Information System (INIS)

    Gaudreau, P.; Quirion, R.; St Pierre, S.; Pert, C.B.

    1983-01-01

    [ 3 H]Pentagastrin binds specifically to an apparent single class of CCK receptors on slide-mounted sections of rat brain (KD . 5.6 nM; Bmax . 36.6 fmol/mg protein). This specific binding is temperature-dependent and regulated by ions and nucleotides. The relative potencies of C-terminal fragments of CCK-8(SO 3 H), benzotript and proglumide in inhibiting specific [ 3 H]pentagastrin binding to CCK brain receptors reinforce the concept of different brain and pancreas CCK receptors. CCK receptors were visualized by using tritium-sensitive LKB film analyzed by computerized densitometry. CCK receptors are highly concentrated in the cortex, dentate gyrus, granular and external plexiform layers of the olfactory bulb, anterior olfactory nuclei, olfactory tubercle, claustrum, accumbens nucleus, some nuclei of the amygdala, thalamus and hypothalamus

  17. Calcium Signaling in Mitral Cell Dendrites of Olfactory Bulbs of Neonatal Rats and Mice during Olfactory Nerve Stimulation and Beta-Adrenoceptor Activation

    Science.gov (United States)

    Yuan, Qi; Mutoh, Hiroki; Debarbieux, Franck; Knopfel, Thomas

    2004-01-01

    Synapses formed by the olfactory nerve (ON) provide the source of excitatory synaptic input onto mitral cells (MC) in the olfactory bulb. These synapses, which relay odor-specific inputs, are confined to the distally tufted single primary dendrites of MCs, the first stage of central olfactory processing. Beta-adrenergic modulation of electrical…

  18. Olfactory ensheathing glia : their contribution to primary olfactory nervous system regeneration and their regenerative potential following transplantation into the injured spinal cord

    NARCIS (Netherlands)

    Franssen, Elske H P; de Bree, Freddy M; Verhaagen, J.

    2007-01-01

    Olfactory ensheathing glia (OEG) are a specialized type of glia that guide primary olfactory axons from the neuroepithelium in the nasal cavity to the brain. The primary olfactory system is able to regenerate after a lesion and OEG contribute to this process by providing a growth-supportive

  19. Assessment of olfactory nerve by SPECT-MRI image with nasal thallium-201 administration in patients with olfactory impairments in comparison to healthy volunteers.

    Directory of Open Access Journals (Sweden)

    Hideaki Shiga

    Full Text Available PURPOSE: The aim of this study was to assess whether migration of thallium-201 ((201Tl to the olfactory bulb were reduced in patients with olfactory impairments in comparison to healthy volunteers after nasal administration of (201Tl. PROCEDURES: 10 healthy volunteers and 21 patients enrolled in the study (19 males and 12 females; 26-71 years old. The causes of olfactory dysfunction in the patients were head trauma (n = 7, upper respiratory tract infection (n = 7, and chronic rhinosinusitis (n = 7. (201TlCl was administered unilaterally to the olfactory cleft, and SPECT-CT was conducted 24 h later. Separate MRI images were merged with the SPECT images. (201Tl olfactory migration was also correlated with the volume of the olfactory bulb determined from MRI images, as well as with odor recognition thresholds measured by using T&T olfactometry. RESULTS: Nasal (201Tl migration to the olfactory bulb was significantly lower in the olfactory-impaired patients than in healthy volunteers. The migration of (201Tl to the olfactory bulb was significantly correlated with odor recognition thresholds obtained with T&T olfactometry and correlated with the volume of the olfactory bulb determined from MRI images when all subjects were included. CONCLUSIONS: Assessment of the (201Tl migration to the olfactory bulb was the new method for the evaluation of the olfactory nerve connectivity in patients with impaired olfaction.

  20. Evolution and development of the vertebrate ear

    Science.gov (United States)

    Fritzsch, B.; Beisel, K. W.

    2001-01-01

    This review outlines major aspects of development and evolution of the ear, specifically addressing issues of cell fate commitment and the emerging molecular governance of these decisions. Available data support the notion of homology of subsets of mechanosensors across phyla (proprioreceptive mechanosensory neurons in insects, hair cells in vertebrates). It is argued that this conservation is primarily related to the specific transducing environment needed to achieve mechanosensation. Achieving this requires highly conserved transcription factors that regulate the expression of the relevant structural genes for mechanosensory transduction. While conserved at the level of some cell fate assignment genes (atonal and its mammalian homologue), the ear has also radically reorganized its development by implementing genes used for cell fate assignment in other parts of the developing nervous systems (e.g., neurogenin 1) and by evolving novel sets of genes specifically associated with the novel formation of sensory neurons that contact hair cells (neurotrophins and their receptors). Numerous genes have been identified that regulate morphogenesis, but there is only one common feature that emerges at the moment: the ear appears to have co-opted genes from a large variety of other parts of the developing body (forebrain, limbs, kidneys) and establishes, in combination with existing transcription factors, an environment in which those genes govern novel, ear-related morphogenetic aspects. The ear thus represents a unique mix of highly conserved developmental elements combined with co-opted and newly evolved developmental elements.

  1. Osteomielitis vertebral piógena Pyogenic vertebral osteomyelitis

    Directory of Open Access Journals (Sweden)

    Pedro P. Perrotti

    2009-10-01

    Full Text Available La osteomielitis vertebral piógena (OVP es una localización poco frecuente (2-7% Se confirma con el aislamiento de un microorganismo de una vértebra, disco intervertebral, absceso epidural o paravertebral. Se describe una serie de casos por la infrecuente presentación de esta enfermedad, que puede ser consulta inicial en los servicios de clínica médica y por su sintomatología inespecífica que supone una dificultad diagnóstica. Tanto la columna lumbar como la dorsal fueron los sitios más afectados. El dolor dorsolumbar y la paraparesia fueron los síntomas más frecuentes de presentación. En ocho pacientes se aislaron Staphylococcus aureus, en uno Escherichia coli y en el restante Haemophylus sp. Se observó leucocitosis sólo en tres pacientes, y en dos velocidad de sedimentación globular mayor de 100 mm/h. Los diez pacientes presentaron imágenes características de osteomielitis vertebral piógena en la resonancia nuclear magnética. Dentro de las complicaciones, los abscesos paravertebrales y epidurales fueron los más frecuentes (en cinco enfermos. Además, un paciente presentó empiema pleural. De los diez pacientes de esta serie, siete recibieron inicialmente tratamiento médico empírico y luego específico para el germen aislado. En los restantes el tratamiento fue guiado de acuerdo al antibiograma. A dos enfermos fue necesario realizarles laminectomía descompresiva por compromiso de partes blandas y a otros dos estabilización quirúrgica por inestabilidad espinal, observándose buena evolución en todos los casos. Esta serie demuestra que, ante un paciente con dolor dorsolumbar y síntomas neurológicos se deberá tener en cuenta esta entidad para evitar un retraso en el tratamiento.Pyogenic osteomyelitis seldom affects the spine (2-7%. It is diagnosed by the isolation of a bacterial agent in the vertebral body, the intervertebral disks or from paravertebral or epidural abscesses. We report a retrospective study of ten

  2. Time frequency analysis of olfactory induced EEG-power change.

    Directory of Open Access Journals (Sweden)

    Valentin Alexander Schriever

    Full Text Available The objective of the present study was to investigate the usefulness of time-frequency analysis (TFA of olfactory-induced EEG change with a low-cost, portable olfactometer in the clinical investigation of smell function.A total of 78 volunteers participated. The study was composed of three parts where olfactory stimuli were presented using a custom-built olfactometer. Part I was designed to optimize the stimulus as well as the recording conditions. In part II EEG-power changes after olfactory/trigeminal stimulation were compared between healthy participants and patients with olfactory impairment. In Part III the test-retest reliability of the method was evaluated in healthy subjects.Part I indicated that the most effective paradigm for stimulus presentation was cued stimulus, with an interstimulus interval of 18-20s at a stimulus duration of 1000ms with each stimulus quality presented 60 times in blocks of 20 stimuli each. In Part II we found that central processing of olfactory stimuli analyzed by TFA differed significantly between healthy controls and patients even when controlling for age. It was possible to reliably distinguish patients with olfactory impairment from healthy individuals at a high degree of accuracy (healthy controls vs anosmic patients: sensitivity 75%; specificity 89%. In addition we could show a good test-retest reliability of TFA of chemosensory induced EEG-power changes in Part III.Central processing of olfactory stimuli analyzed by TFA reliably distinguishes patients with olfactory impairment from healthy individuals at a high degree of accuracy. Importantly this can be achieved with a simple olfactometer.

  3. State and trait olfactory markers of major depression.

    Directory of Open Access Journals (Sweden)

    Marine Naudin

    Full Text Available Nowadays, depression is a major issue in public health. Because of the partial overlap between the brain structures involved in depression, olfaction and emotion, the study of olfactory function could be a relevant way to find specific cognitive markers of depression. This study aims at determining whether the olfactory impairments are state or trait markers of major depressive episode (MDE through the study of the olfactory parameters involving the central olfactory pathway. In a pilot study, we evaluated prospectively 18 depressed patients during acute episodes of depression and 6 weeks after antidepressant treatment (escitalopram against 54 healthy volunteers, matched by age, gender and smoking status. We investigated the participants' abilities to identify odors (single odors and in binary mixture, to evaluate and discriminate the odors' intensity, and determine the hedonic valence of odors. The results revealed an "olfactory anhedonia" expressed by decrease of hedonic score for high emotional odorant as potential state marker of MDE. Moreover, these patients experienced an "olfactory negative alliesthesia", during the odor intensity evaluation, and failed to identify correctly two odorants with opposite valences in a binary iso-mixture, which constitute potential trait markers of the disease. This study provides preliminary evidence for olfactory impairments associated with MDE (state marker that are persistent after the clinical improvement of depressive symptoms (trait marker. These results could be explained by the chronicity of depression and/or by the impact of therapeutic means used (antidepressant treatment. They need to be confirmed particularly the ones obtained in complex olfactory environment which corresponds a more objective daily life situation.

  4. Effect of strong fragrance on olfactory detection threshold.

    Science.gov (United States)

    Fasunla, Ayotunde James; Douglas, David Dayo; Adeosun, Aderemi Adeleke; Steinbach, Silke; Nwaorgu, Onyekwere George Benjamin

    2014-09-01

    To assess the olfactory threshold of healthy volunteers at the University College Hospital, Ibadan and to investigate the effect of perfume on their olfactory detection thresholds. A quasi-experimental study on olfactory detection thresholds of healthy volunteers from September 2013 to November 2013. Tertiary health institution. A structured questionniare was administered to the participants in order to obtain information on sociodemographics, occupation, ability to perceive smell, use of perfume, effects of perfume on appetite and self-confidence, history of allergy, and previous nasal surgery. Participants subjectively rated their olfactory performance. Subsequently, they had olfactory detection threshold testing done at baseline and after exposure to perfume with varied concentrations of n-butanol in a forced triple response and staircase fashion. Healthy volunteers, 37 males and 63 females, were evaluated. Their ages ranged from 19 to 59 years with a mean of 31 years ± 8. Subjectively, 94% of the participants had excellent olfactory function. In the pre-exposure forced triple response, 88% were able to detect the odor at ≤.25 mmol/l concentration while in the post-exposure forced triple response, only 66% were able to detect the odor at ≤.25 mmol/l concentration. There is also a statistical significant difference in the olfactory detection threshold score between the pre-exposure and post-exposure period in the participants (P fragrances affects the olfactory detection threshold. Therefore patients and clinicians should be aware of this and its effects on the outcome of test of olfaction. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  5. Expression of calmodulin mRNA in rat olfactory neuroepithelium.

    Science.gov (United States)

    Biffo, S; Goren, T; Khew-Goodall, Y S; Miara, J; Margolis, F L

    1991-04-01

    A calmodulin (CaM) cDNA was isolated by differential hybridization screening of a lambda gt10 library prepared from rat olfactory mucosa. This cDNA fragment, containing most of the open reading frame of the rat CaMI gene, was subcloned and used to characterize steady-state expression of CaM mRNA in rat olfactory neuroepithelium and bulb. Within the bulb mitral cells are the primary neuronal population expressing CaM mRNA. The major CaM mRNA expressed in the olfactory mucosa is 1.7 kb with smaller contributions from mRNAs of 4.0 and 1.4 kb. CaM mRNA was primarily associated with the olfactory neurons and, despite the cellular complexity of the tissue and the known involvement of CaM in diverse cellular processes, was only minimally evident in sustentacular cells, gland cells or respiratory epithelium. Following bulbectomy CaM mRNA declines in the olfactory neuroepithelium as does olfactory marker protein (OMP) mRNA. In contrast to the latter, CaM mRNA makes a partial recovery by one month after surgery. These results, coupled with those from in situ hybridization, indicate that CaM mRNA is expressed in both mature and immature olfactory neurons. The program regulating CaM gene expression in olfactory neurons is distinct from those controlling expression of B50/GAP43 in immature, or OMP in mature, neurons respectively.

  6. A Specialized Odor Memory Buffer in Primary Olfactory Cortex

    OpenAIRE

    Zelano, Christina; Montag, Jessica; Khan, Rehan; Sobel, Noam

    2009-01-01

    Background The neural substrates of olfactory working memory are unknown. We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes. Methodology/Principal Findings We used functional magnetic resonance imaging to measure activity in the brains of subjects who were remembering either nameable or unnameable odorants. We found a double dissociat...

  7. Olfactory Dysfunction as an Early Biomarker in Parkinson's Disease

    Institute of Scientific and Technical Information of China (English)

    Michelle E.Fullard; James F.Morley; John E.Duda

    2017-01-01

    Olfactory dysfunction is common in Parkinson's disease (PD) and often predates the diagnosis by years,reflecting early deposition of Lewy pathology,the histologic hallmark of PD,in the olfactory bulb.Clinical tests are available that allow for the rapid characterization of olfactory dysfunction,including tests of odor identification,discrimination,detection,and recognition thresholds,memory,and tests assessing the build-up of odor intensity across increasing suprathreshold stimulus concentrations.The high prevalence of olfactory impairment,along with the ease and low cost of assessment,has fostered great interest in olfaction as a potential biomarker for PD.Hyposmia may help differentiate PD from other causes of parkinsonism,and may also aid in the identification of "pre-motor" PD due to the early pathologic involvement of olfactory pathways.Olfactory function is also correlated with other non-motor features of PD and may serve as a predictor of cognitive decline.In this article,we summarize the existing literature on olfaction in PD,focusing on the potential for olfaction as a biomarker for early or differential diagnosis and prognosis.

  8. Brain activation associated to olfactory conditioned same-sex partner preference in male rats.

    Science.gov (United States)

    Coria-Avila, Genaro A; Cibrian-Llanderal, Tamara; Díaz-Estrada, Victor X; García, Luis I; Toledo-Cárdenas, Rebeca; Pfaus, James G; Manzo, Jorge

    2018-03-01

    Sexual preferences can be strongly modified by Pavlovian learning. For instance, olfactory conditioned same-sex partner preference can occur when a sexually naïve male cohabits with an scented male during repeated periods under the effects of enhanced D2-type activity. Preference is observed days later via social and sexual behaviors. Herein we explored brain activity related to learned same-sex preference (Fos-Immunoreactivity, IR) following exposure to a conditioned odor paired with same-sex preference. During conditioning trials males received either saline or the D2-type receptor agonist quinpirole (QNP) and cohabitated during 24 h with a stimulus male that bore almond scent on the back as conditioned stimulus. This was repeated every 4 days, for a total of three trials. In a drug-free final test we assessed socio/sexual partner preference between the scented male and a receptive female. The results indicated that QNP-conditioned males developed a same-sex preference observed via contact, time spent, olfactory investigations, and non-contact erections. By contrast, saline-conditioned and intact (non-exposed to conditioning) males expressed an unconditioned preference for the female. Four days later the males were exposed to almond scent and their brains were processed for Fos-IR. Results indicated that the QNP-conditioned group expressed more Fos-IR in the nucleus accumbens (AcbSh), medial preoptic area (MPA), piriform cortex (Pir) and ventromedial nucleus of the hypothalamus (VMH) as compared to saline-conditioned. Intact males expressed the lowest Fos-IR in AcbSh and VMH, but the highest in MPA and Pir. We discuss the role of these areas in the learning process of same-sex partner preferences and olfactory discrimination. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Renal cystic disease proteins play critical roles in the organization of the olfactory epithelium.

    Directory of Open Access Journals (Sweden)

    Jennifer L Pluznick

    Full Text Available It was reported that some proteins known to cause renal cystic disease (NPHP6; BBS1, and BBS4 also localize to the olfactory epithelium (OE, and that mutations in these proteins can cause anosmia in addition to renal cystic disease. We demonstrate here that a number of other proteins associated with renal cystic diseases - polycystin 1 and 2 (PC1, PC2, and Meckel-Gruber syndrome 1 and 3 (MKS1, MKS3 - localize to the murine OE. PC1, PC2, MKS1 and MKS3 are all detected in the OE by RT-PCR. We find that MKS3 localizes specifically to dendritic knobs of olfactory sensory neurons (OSNs, while PC1 localizes to both dendritic knobs and cilia of mature OSNs. In mice carrying mutations in MKS1, the expression of the olfactory adenylate cyclase (AC3 is substantially reduced. Moreover, in rats with renal cystic disease caused by a mutation in MKS3, the laminar organization of the OE is perturbed and there is a reduced expression of components of the odor transduction cascade (G(olf, AC3 and α-acetylated tubulin. Furthermore, we show with electron microscopy that cilia in MKS3 mutant animals do not manifest the proper microtubule architecture. Both MKS1 and MKS3 mutant animals show no obvious alterations in odor receptor expression. These data show that multiple renal cystic proteins localize to the OE, where we speculate that they work together to regulate aspects of the development, maintenance or physiological activities of cilia.

  10. Connectivity from OR37 expressing olfactory sensory neurons to distinct cell types in the hypothalamus

    Directory of Open Access Journals (Sweden)

    Andrea eBader

    2012-11-01

    Full Text Available Olfactory sensory neurons which express a member from the OR37 subfamily of odorant receptor genes are wired to the main olfactory bulb in a unique monoglomerular fashion; from these glomeruli an untypical connectivity into higher brain centers exists. In the present study we have investigated by DiI and transsynaptic tracing approaches how the connection pattern from these glomeruli into distinct hypothalamic nuclei is organized. The application of DiI onto the ventral domain of the bulb which harbors the OR37 glomeruli resulted in the labeling of fibers within the paraventricular and supraoptic nucleus of the hypothalamus; some of these fibers were covered with varicose-like structures. No DiI-labeled cell somata were detectable in these nuclei. The data indicate that projection neurons which originate in the OR37 region of the main olfactory bulb form direct connections into these nuclei. The cells that were labeled by the transsynaptic tracer WGA in these nuclei were further characterized. Their distribution pattern in the paraventricular nucleus was reminiscent of cells which produce distinct neuropeptides. Double labeling experiments confirmed that they contained vasopressin, but not the related neuropeptide oxytocin. Morphological analysis revealed that they comprise of magno- and parvocellular cells. A comparative investigation of the WGA-positive cells in the supraoptic nucleus demonstrated that these were vasopressin-positive, as well, whereas oxytocin-producing cells of this nucleus also contained no transsynaptic tracer. Together, the data demonstrate a connectivity from OR37 expressing sensory neurons to distinct hypothalamic neurons with the same neuropeptide content.

  11. CIRSE Guidelines on Percutaneous Vertebral Augmentation

    Energy Technology Data Exchange (ETDEWEB)

    Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Too, Chow Wei, E-mail: spyder55@gmail.com; Koch, Guillaume, E-mail: guillaume.koch@gmail.com; Caudrelier, Jean, E-mail: jean.caudrelier@chru-strasbourg.fr; Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Garnon, Julien, E-mail: juliengarnon@gmail.com; Gangi, Afshin, E-mail: gangi@unistra.fr [Strasbourg University Hospital, Interventional Radiology Department (France)

    2017-03-15

    Vertebral compression fracture (VCF) is an important cause of severe debilitating back pain, adversely affecting quality of life, physical function, psychosocial performance, mental health and survival. Different vertebral augmentation procedures (VAPs) are used in order to consolidate the VCFs, relief pain,and whenever posible achieve vertebral body height restoration. In the present review we give the indications, contraindications, safety profile and outcomes of the existing percutaneous VAPs.

  12. Type 2 diabetes impairs odour detection, olfactory memory and olfactory neuroplasticity; effects partly reversed by the DPP-4 inhibitor Linagliptin.

    Science.gov (United States)

    Lietzau, Grazyna; Davidsson, William; Östenson, Claes-Göran; Chiazza, Fausto; Nathanson, David; Pintana, Hiranya; Skogsberg, Josefin; Klein, Thomas; Nyström, Thomas; Darsalia, Vladimer; Patrone, Cesare

    2018-02-23

    Recent data suggest that olfactory deficits could represent an early marker and a pathogenic mechanism at the basis of cognitive decline in type 2 diabetes (T2D). However, research is needed to further characterize olfactory deficits in diabetes, their relation to cognitive decline and underlying mechanisms.The aim of this study was to determine whether T2D impairs odour detection, olfactory memory as well as neuroplasticity in two major brain areas responsible for olfaction and odour coding: the main olfactory bulb (MOB) and the piriform cortex (PC), respectively. Dipeptidyl peptidase-4 inhibitors (DPP-4i) are clinically used T2D drugs exerting also beneficial effects in the brain. Therefore, we aimed to determine whether DPP-4i could reverse the potentially detrimental effects of T2D on the olfactory system.Non-diabetic Wistar and T2D Goto-Kakizaki rats, untreated or treated for 16 weeks with the DPP-4i linagliptin, were employed. Odour detection and olfactory memory were assessed by using the block, the habituation-dishabituation and the buried pellet tests. We assessed neuroplasticity in the MOB by quantifying adult neurogenesis and GABAergic inhibitory interneurons positive for calbindin, parvalbumin and carletinin. In the PC, neuroplasticity was assessed by quantifying the same populations of interneurons and a newly identified form of olfactory neuroplasticity mediated by post-mitotic doublecortin (DCX) + immature neurons.We show that T2D dramatically reduced odour detection and olfactory memory. Moreover, T2D decreased neurogenesis in the MOB, impaired the differentiation of DCX+ immature neurons in the PC and altered GABAergic interneurons protein expression in both olfactory areas. DPP-4i did not improve odour detection and olfactory memory. However, it normalized T2D-induced effects on neuroplasticity.The results provide new knowledge on the detrimental effects of T2D on the olfactory system. This knowledge could constitute essentials for

  13. Delayed vertebral diagnosed L4 pincer vertebral fracture, L2-L3 ruptured vertebral lumbar disc hernia, L5 vertebral wedge fracture - Case report

    OpenAIRE

    Balasa D; Schiopu M; Tunas A; Baz R; Hancu Anca

    2016-01-01

    An association between delayed ruptured lumbar disc hernia, L5 vertebral wedge fracture and posttraumaticL4 pincer vertebral fracture (A2.3-AO clasification) at different levels is a very rare entity. We present the case of a 55 years old male who falled down from a bicycle. 2 months later because of intense and permanent vertebral lumbar and radicular L2 and L3 pain (Visual Scal Autologus of Pain7-8/10) the patient came to the hospital. He was diagnosed with pincer vertebral L4 fracture (A2....

  14. Hemifacial spasm; The value of vertebral angiography

    International Nuclear Information System (INIS)

    Yang, Hak Seok; Kim, Myung Soon; Han, Yong Pyo

    1992-01-01

    In order to evaluate the value of vertebral angiography in assesment of hemifacial spasm, We reviewed retrospectively the vertebral angiography of 28 patients (30 cases) with surgically proved hemifacial spasm but normal CT scans of posterior fossa. There were 9 males and 19 females. Angiography revealed vascular focus of hemifacial spasm located at anterior inferior cerebellar artery , posterior inferior cerebellar artery, and vertebral artery in 19, 9, and 2 cases respectively. Right side was involved in 20 cases. All involved vessels were elongated, tortuous, and dilated. In conclusion, vertebral angiography was valuable in evaluating hemifacial spasm of vascular origin in the posterior fossa

  15. Inducible activation of ERK5 MAP kinase enhances adult neurogenesis in the olfactory bulb and improves olfactory function.

    Science.gov (United States)

    Wang, Wenbin; Lu, Song; Li, Tan; Pan, Yung-Wei; Zou, Junhui; Abel, Glen M; Xu, Lihong; Storm, Daniel R; Xia, Zhengui

    2015-05-20

    Recent discoveries have suggested that adult neurogenesis in the subventricular zone (SVZ) and olfactory bulb (OB) may be required for at least some forms of olfactory behavior in mice. However, it is unclear whether conditional and selective enhancement of adult neurogenesis by genetic approaches is sufficient to improve olfactory function under physiological conditions or after injury. Furthermore, specific signaling mechanisms regulating adult neurogenesis in the SVZ/OB are not fully defined. We previously reported that ERK5, a MAP kinase selectively expressed in the neurogenic regions of the adult brain, plays a critical role in adult neurogenesis in the SVZ/OB. Using a site-specific knock-in mouse model, we report here that inducible and targeted activation of the endogenous ERK5 in adult neural stem/progenitor cells enhances adult neurogenesis in the OB by increasing cell survival and neuronal differentiation. This conditional ERK5 activation also improves short-term olfactory memory and odor-cued associative olfactory learning under normal physiological conditions. Furthermore, these mice show enhanced recovery of olfactory function and have more adult-born neurons after a zinc sulfate-induced lesion of the main olfactory epithelium. We conclude that ERK5 MAP kinase is an important endogenous signaling pathway regulating adult neurogenesis in the SVZ/OB, and that conditional activation of endogenous ERK5 is sufficient to enhance adult neurogenesis in the OB thereby improving olfactory function both under normal conditions and after injury. Copyright © 2015 the authors 0270-6474/15/357833-17$15.00/0.

  16. 2R and remodeling of vertebrate signal transduction engine

    Directory of Open Access Journals (Sweden)

    Huminiecki Lukasz

    2010-12-01

    Full Text Available Abstract Background Whole genome duplication (WGD is a special case of gene duplication, observed rarely in animals, whereby all genes duplicate simultaneously through polyploidisation. Two rounds of WGD (2R-WGD occurred at the base of vertebrates, giving rise to an enormous wave of genetic novelty, but a systematic analysis of functional consequences of this event has not yet been performed. Results We show that 2R-WGD affected an overwhelming majority (74% of signalling genes, in particular developmental pathways involving receptor tyrosine kinases, Wnt and transforming growth factor-β ligands, G protein-coupled receptors and the apoptosis pathway. 2R-retained genes, in contrast to tandem duplicates, were enriched in protein interaction domains and multifunctional signalling modules of Ras and mitogen-activated protein kinase cascades. 2R-WGD had a fundamental impact on the cell-cycle machinery, redefined molecular building blocks of the neuronal synapse, and was formative for vertebrate brains. We investigated 2R-associated nodes in the context of the human signalling network, as well as in an inferred ancestral pre-2R (AP2R network, and found that hubs (particularly involving negative regulation were preferentially retained, with high connectivity driving retention. Finally, microarrays and proteomics demonstrated a trend for gradual paralog expression divergence independent of the duplication mechanism, but inferred ancestral expression states suggested preferential subfunctionalisation among 2R-ohnologs (2ROs. Conclusions The 2R event left an indelible imprint on vertebrate signalling and the cell cycle. We show that 2R-WGD preferentially retained genes are associated with higher organismal complexity (for example, locomotion, nervous system, morphogenesis, while genes associated with basic cellular functions (for example, translation, replication, splicing, recombination; with the notable exception of cell cycle tended to be excluded. 2R

  17. Evolution of vertebrate mechanosensory hair cells and inner ears: toward identifying stimuli that select mutation driven altered morphologies

    Science.gov (United States)

    Fritzsch, Bernd; Straka, Hans

    2014-01-01

    Among the major distance senses of vertebrates, the ear is unique in its complex morphological changes during evolution. Conceivably, these changes enable the ear to adapt toward sensing various physically well-characterized stimuli. This review develops a scenario that integrates sensory cell with organ evolution. We propose that molecular and cellular evolution of the vertebrate hair cells occurred prior to the formation of the vertebrate ear. We previously proposed that the genes driving hair cell differentiation, were aggregated in the otic region through developmental re-patterning that generated a unique vertebrate embryonic structure, the otic placode. In agreement with the presence of graviceptive receptors in many vertebrate outgroups, it is likely that the vertebrate ear originally functioned as a simple gravity-sensing organ. Based on the rare occurrence of angular acceleration receptors in vertebrate outgroups, we further propose that the canal system evolved with a more sophisticated ear morphogenesis. This evolving morphogenesis obviously turned the initial otocyst into a complex set of canals and recesses, harboring multiple sensory epithelia each adapted to the acquisition of a specific aspect of a given physical stimulus. As support for this evolutionary progression, we provide several details of the molecular basis of ear development. PMID:24281353

  18. Induction of Associative Olfactory Memory by Targeted Activation of Single Olfactory Neurons in Drosophila Larvae

    OpenAIRE

    Honda, Takato; Lee, Chi-Yu; Yoshida-Kasikawa, Maki; Honjo, Ken; Furukubo-Tokunaga, Katsuo

    2014-01-01

    It has been postulated that associative memory is formed by at least two sets of external stimuli, CS and US, that are transmitted to the memory centers by distinctive conversing pathways. However, whether associative memory can be induced by the activation of only the olfactory CS and a biogenic amine-mediated US pathways remains to be elucidated. In this study, we substituted the reward signals with dTrpA1-mediated thermogenetic activation of octopaminergic neurons and the odor signals by C...

  19. Protein tyrosine phosphatase receptor type R deficient mice exhibit increased exploration in a new environment and impaired novel object recognition memory

    NARCIS (Netherlands)

    Erkens, M.; Bakker, B.; Duijn, L.M. van; Hendriks, W.J.A.J.; Zee, C.E.E.M. van der

    2014-01-01

    Mouse gene Ptprr encodes multiple protein tyrosine phosphatase receptor type R (PTPRR) isoforms that negatively regulate mitogen-activated protein kinase (MAPK) signaling pathways. In the mouse brain, PTPRR proteins are expressed in cerebellum, olfactory bulb, hippocampus, amygdala and perirhinal

  20. Activation of Six1 Expression in Vertebrate Sensory Neurons.

    Directory of Open Access Journals (Sweden)

    Shigeru Sato

    Full Text Available SIX1 homeodomain protein is one of the essential key regulators of sensory organ development. Six1-deficient mice lack the olfactory epithelium, vomeronasal organs, cochlea, vestibule and vestibuloacoustic ganglion, and also show poor neural differentiation in the distal part of the cranial ganglia. Simultaneous loss of both Six1 and Six4 leads to additional abnormalities such as small trigeminal ganglion and abnormal dorsal root ganglia (DRG. The aim of this study was to understand the molecular mechanism that controls Six1 expression in sensory organs, particularly in the trigeminal ganglion and DRG. To this end, we focused on the sensory ganglia-specific Six1 enhancer (Six1-8 conserved between chick and mouse. In vivo reporter assays using both animals identified an important core region comprising binding consensus sequences for several transcription factors including nuclear hormone receptors, TCF/LEF, SMAD, POU homeodomain and basic-helix-loop-helix proteins. The results provided information on upstream factors and signals potentially relevant to Six1 regulation in sensory neurons. We also report the establishment of a new transgenic mouse line (mSix1-8-NLSCre that expresses Cre recombinase under the control of mouse Six1-8. Cre-mediated recombination was detected specifically in ISL1/2-positive sensory neurons of Six1-positive cranial sensory ganglia and DRG. The unique features of the mSix1-8-NLSCre line are the absence of Cre-mediated recombination in SOX10-positive glial cells and central nervous system and ability to induce recombination in a subset of neurons derived from the olfactory placode/epithelium. This mouse model can be potentially used to advance research on sensory development.

  1. Nonlinear dynamics of pattern formation and pattern recognition in the rabbit olfactory bulb

    Science.gov (United States)

    Baird, Bill

    1986-10-01

    A mathematical model of the process of pattern recognition in the first olfactory sensory cortex of the rabbit is presented. It explains the formation and alteration of spatial patterns in neural activity observed experimentally during classical Pavlovian conditioning. On each inspiration of the animal, a surge of receptor input enters the olfactory bulb. EEG activity recorded at the surface of the bulb undergoes a transition from a low amplitude background state of temporal disorder to coherent oscillation. There is a distinctive spatial pattern of rms amplitude in this oscillation which changes reliably to a second pattern during each successful recognition by the animal of a conditioned stimulus odor. When a new odor is paired as conditioned stimulus, these patterns are replaced by new patterns that stabilize as the animal adapts to the new environment. I will argue that a unification of the theories of pattern formation and associative memory is required to account for these observations. This is achieved in a model of the bulb as a discrete excitable medium with spatially inhomogeneous coupling expressed by a connection matrix. The theory of multiple Hopf bifurcations is employed to find coupled equations for the amplitudes of competing unstable oscillatory modes. These may be created in the system by proper coupling and selectively evoked by specific classes of inputs. This allows a view of limit cycle attractors as “stored” fixed points of a gradient vector field and thereby recovers the more familiar dynamical systems picture of associative memory.

  2. Gamma neurons mediate dopaminergic input during aversive olfactory memory formation in Drosophila.

    Science.gov (United States)

    Qin, Hongtao; Cressy, Michael; Li, Wanhe; Coravos, Jonathan S; Izzi, Stephanie A; Dubnau, Joshua

    2012-04-10

    Mushroom body (MB)-dependent olfactory learning in Drosophila provides a powerful model to investigate memory mechanisms. MBs integrate olfactory conditioned stimulus (CS) inputs with neuromodulatory reinforcement (unconditioned stimuli, US), which for aversive learning is thought to rely on dopaminergic (DA) signaling to DopR, a D1-like dopamine receptor expressed in MBs. A wealth of evidence suggests the conclusion that parallel and independent signaling occurs downstream of DopR within two MB neuron cell types, with each supporting half of memory performance. For instance, expression of the Rutabaga (Rut) adenylyl cyclase in γ neurons is sufficient to restore normal learning to rut mutants, whereas expression of Neurofibromatosis 1 (NF1) in α/β neurons is sufficient to rescue NF1 mutants. DopR mutations are the only case where memory performance is fully eliminated, consistent with the hypothesis that DopR receives the US inputs for both γ and α/β lobe traces. We demonstrate, however, that DopR expression in γ neurons is sufficient to fully support short- and long-term memory. We argue that DA-mediated CS-US association is formed in γ neurons followed by communication between γ and α/β neurons to drive consolidation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Functional Differences between Global Pre- and Postsynaptic Inhibition in the Drosophila Olfactory Circuit.

    Science.gov (United States)

    Oizumi, Masafumi; Satoh, Ryota; Kazama, Hokto; Okada, Masato

    2012-01-01

    The Drosophila antennal lobe is subdivided into multiple glomeruli, each of which represents a unique olfactory information processing channel. In each glomerulus, feedforward input from olfactory receptor neurons (ORNs) is transformed into activity of projection neurons (PNs), which represent the output. Recent investigations have indicated that lateral presynaptic inhibitory input from other glomeruli controls the gain of this transformation. Here, we address why this gain control acts "pre"-synaptically rather than "post"-synaptically. Postsynaptic inhibition could work similarly to presynaptic inhibition with regard to regulating the firing rates of PNs depending on the stimulus intensity. We investigate the differences between pre- and postsynaptic gain control in terms of odor discriminability by simulating a network model of the Drosophila antennal lobe with experimental data. We first demonstrate that only presynaptic inhibition can reproduce the type of gain control observed in experiments. We next show that presynaptic inhibition decorrelates PN responses whereas postsynaptic inhibition does not. Due to this effect, presynaptic gain control enhances the accuracy of odor discrimination by a linear decoder while its postsynaptic counterpart only diminishes it. Our results provide the reason gain control operates "pre"-synaptically but not "post"-synaptically in the Drosophila antennal lobe.

  4. Functional differences between global pre- and postsynaptic inhibition in the Drosophila olfactory circuit

    Directory of Open Access Journals (Sweden)

    Masafumi eOizumi

    2012-03-01

    Full Text Available The Drosophila antennal lobe is subdivided into multiple glomeruli, each of which represents a unique olfactory information processing channel. In each glomerulus, feedforward input from olfactory receptor neurons (ORNs is transformed into activity of projection neurons (PNs, which represent the output. Recent investigations have indicated that lateral pre-synaptic inhibitory input from other glomeruli controls the gain of this transformation. Here, we address why this gain control acts `pre'-synaptically rather than `post'-synaptically. Postsynaptic inhibition could work similarly to presynaptic inhibition with regard to regulating the firing rates of PNs depending on the stimulus intensity. We investigate the differences between pre- and postsynaptic gain control in terms of odor discriminability by simulating a network model of the Drosophila antennal lobe with experimental data. We first demonstrate that only presynaptic inhibition can reproduce the type of gain control observed in experiments. We next show that presynaptic inhibition decorrelates PN responses whereas postsynaptic inhibition does not. Due to this effect, presynaptic gain control enhances the accuracy of odor discrimination by a linear decoder while its postsynaptic counterpart only diminishes it. Our results provide the reason gain control operates `pre'-synaptically but not `post'-synaptically in the Drosophila antennal lobe.

  5. Ontogenetic scaling of the olfactory antennae and flicking behavior of the shore crab, Hemigrapsus oregonensis.

    Science.gov (United States)

    Waldrop, Lindsay D

    2013-07-01

    Malacostracan crustaceans such as crabs flick antennae with arrays of olfactory sensilla called aesthetascs through the water to sense odors. Flicking by crabs consists of a quick downstroke, in which aesthetascs are deflected laterally (splayed), and a slower, reversed return stroke, in which aesthetascs clump together. This motion causes water to be flushed within and then held in between aesthetascs to deliver odor molecules to olfactory receptors. Although this odor sampling method relies on a narrow range of speeds, sizes, and specific arrangements of aesthetascs, most crabs dramatically change these during ontogeny. In this study, the morphometrics of the aesthetascs, array, and antennae and the flicking kinematics of the Oregon shore crab, Hemigrapsus oregonensis (Decapoda: Brachyura), are examined to determine their scaling relationships during ontogeny. The morphometrics of the array and antennae increase more slowly than would be predicted by isometry. Juvenile crabs' aesthetascs splay relatively further apart than adults, likely due to changing material properties of aesthetasc cuticle during growth. These results suggest that disproportionate growth and altered aesthetasc splay during flicking will mediate the size changes due to growth that would otherwise lead to a loss of function.

  6. Neurogenesis in the olfactory bulb induced by paced mating in the female rat is opioid dependent.