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Sample records for awc-mediated olfactory plasticity

  1. SLEEP AND OLFACTORY CORTICAL PLASTICITY

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    Dylan Barnes

    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.

  2. Sleep and olfactory cortical plasticity

    OpenAIRE

    Barnes, Dylan C.; Wilson, Donald A.

    2014-01-01

    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 stimulat...

  3. SLEEP AND OLFACTORY CORTICAL PLASTICITY

    OpenAIRE

    Dylan Barnes; Wilson, Donald A.

    2014-01-01

    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 stimul...

  4. Regulation of spike timing-dependent plasticity of olfactory inputs in mitral cells in the rat olfactory bulb.

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    Teng-Fei Ma

    Full Text Available The recent history of activity input onto granule cells (GCs in the main olfactory bulb can affect the strength of lateral inhibition, which functions to generate contrast enhancement. However, at the plasticity level, it is unknown whether and how the prior modification of lateral inhibition modulates the subsequent induction of long-lasting changes of the excitatory olfactory nerve (ON inputs to mitral cells (MCs. Here we found that the repetitive stimulation of two distinct excitatory inputs to the GCs induced a persistent modification of lateral inhibition in MCs in opposing directions. This bidirectional modification of inhibitory inputs differentially regulated the subsequent synaptic plasticity of the excitatory ON inputs to the MCs, which was induced by the repetitive pairing of excitatory postsynaptic potentials (EPSPs with postsynaptic bursts. The regulation of spike timing-dependent plasticity (STDP was achieved by the regulation of the inter-spike-interval (ISI of the postsynaptic bursts. This novel form of inhibition-dependent regulation of plasticity may contribute to the encoding or processing of olfactory information in the olfactory bulb.

  5. Olfactory organ of Octopus vulgaris: morphology, plasticity, turnover and sensory characterization.

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    Polese, Gianluca; Bertapelle, Carla; Di Cosmo, Anna

    2016-01-01

    The cephalopod olfactory organ was described for the first time in 1844 by von Kölliker, who was attracted to the pair of small pits of ciliated cells on each side of the head, below the eyes close to the mantle edge, in both octopuses and squids. Several functional studies have been conducted on decapods but very little is known about octopods. The morphology of the octopus olfactory system has been studied, but only to a limited extent on post-hatching specimens, and the only paper on adult octopus gives a minimal description of the olfactory organ. Here, we describe the detailed morphology of young male and female Octopus vulgaris olfactory epithelium, and using a combination of classical morphology and 3D reconstruction techniques, we propose a new classification for O. vulgaris olfactory sensory neurons. Furthermore, using specific markers such as olfactory marker protein (OMP) and proliferating cell nuclear antigen (PCNA) we have been able to identify and differentially localize both mature olfactory sensory neurons and olfactory sensory neurons involved in epithelium turnover. Taken together, our data suggest that the O. vulgaris olfactory organ is extremely plastic, capable of changing its shape and also proliferating its cells in older specimens. PMID:27069253

  6. Olfactory organ of Octopus vulgaris: morphology, plasticity, turnover and sensory characterization

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    Gianluca Polese

    2016-05-01

    Full Text Available The cephalopod olfactory organ was described for the first time in 1844 by von Kölliker, who was attracted to the pair of small pits of ciliated cells on each side of the head, below the eyes close to the mantle edge, in both octopuses and squids. Several functional studies have been conducted on decapods but very little is known about octopods. The morphology of the octopus olfactory system has been studied, but only to a limited extent on post-hatching specimens, and the only paper on adult octopus gives a minimal description of the olfactory organ. Here, we describe the detailed morphology of young male and female Octopus vulgaris olfactory epithelium, and using a combination of classical morphology and 3D reconstruction techniques, we propose a new classification for O. vulgaris olfactory sensory neurons. Furthermore, using specific markers such as olfactory marker protein (OMP and proliferating cell nuclear antigen (PCNA we have been able to identify and differentially localize both mature olfactory sensory neurons and olfactory sensory neurons involved in epithelium turnover. Taken together, our data suggest that the O. vulgaris olfactory organ is extremely plastic, capable of changing its shape and also proliferating its cells in older specimens.

  7. Developing a sense of scents: Plasticity in olfactory placode formation

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    Whitlock, K. E.

    2007-01-01

    The sense organs of the vertebrate head arise predominantly from sensory placodes. The sensory placodes have traditionally been grouped as structures that share common developmental and evolutionary characteristics. In attempts to build a coherent model for development of all placodes, the fascinating differences that make placodes unique are often overlooked. Here I review olfactory placode development with special attention to the origin and cell movements that generate the olfactory placod...

  8. Long term functional plasticity of sensory inputs mediated by olfactory learning

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    Abraham, Nixon; Vincis, Roberto; Lagier, Samuel; Rodriguez, Ivan; Carleton, Alan

    2014-01-01

    Sensory inputs are remarkably organized along all sensory pathways. While sensory representations are known to undergo plasticity at the higher levels of sensory pathways following peripheral lesions or sensory experience, less is known about the functional plasticity of peripheral inputs induced by learning. We addressed this question in the adult mouse olfactory system by combining odor discrimination studies with functional imaging of sensory input activity in awake mice. Here we show that...

  9. Adult Born Olfactory Bulb Dopaminergic Interneurons: Molecular Determinants and Experience-Dependent Plasticity

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    Bonzano, Sara; Bovetti, Serena; Gendusa, Claudio; Peretto, Paolo; De Marchis, Silvia

    2016-01-01

    The olfactory bulb (OB) is a highly plastic brain region involved in the early processing of olfactory information. A remarkably feature of the OB circuits in rodents is the constitutive integration of new neurons that takes place during adulthood. Newborn cells in the adult OB are mostly inhibitory interneurons belonging to chemically, morphologically and functionally heterogeneous types. Although there is general agreement that adult neurogenesis in the OB plays a key role in sensory information processing and olfaction-related plasticity, the contribution of each interneuron subtype to such functions is far to be elucidated. Here, we focus on the dopaminergic (DA) interneurons: we highlight recent findings about their morphological features and then describe the molecular factors required for the specification/differentiation and maintenance of the DA phenotype in adult born neurons. We also discuss dynamic changes of the DA interneuron population related to age, environmental stimuli and lesions, and their possible functional implications. PMID:27199651

  10. Impaired structural hippocampal plasticity is associated with emotional and memory deficits in the olfactory bulbectomized rat.

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    Morales-Medina, J C; Juarez, I; Venancio-García, E; Cabrera, S N; Menard, C; Yu, W; Flores, G; Mechawar, N; Quirion, R

    2013-04-16

    Disturbances in olfactory circuitry have been associated with depression in humans. The olfactory bulbectomized (OBX lesion) has been largely used as a model of depression-like behavior in the rat. However, quantitative neuronal rearrangements in key brain regions in this animal model have not been evaluated yet. Accordingly, we investigated changes in hippocampal plasticity as well as behavioral deficits in this animal model. OBX-induced behavioral deficits were studied in a battery of tests, namely the open field test (OFT), forced swim test (FST), and spatial memory disturbances in the Morris water maze (MWM). To characterize the neuronal remodeling, neuroanatomical rearrangements were investigated in the CA1 hippocampus and piriform cortex (PirC), brain regions receiving inputs from the olfactory bulbs and associated with emotional or olfactory processes. Additionally, cell proliferation and survival of newborn cells in the adult dentate gyrus (DG) of the hippocampus were also determined. OBX induced hyperlocomotion and enhanced rearing and grooming in the OFT, increased immobility in the FST as well as required a longer time to find the hidden platform in the MWM. OBX also induced dendritic atrophy in the hippocampus and PirC. In addition, cell proliferation was decreased while the survival remained unchanged in the DG of these animals. These various features are also observed in depressed subjects, adding further support to the validity and usefulness of this model to evaluate potential novel antidepressants. PMID:23357118

  11. Dietary Restriction Mitigates Cocaine-Induced Alterations of Olfactory Bulb Cellular Plasticity and Gene Expression, and Behavior

    OpenAIRE

    Xu, Xiangru; Mughal, Mohamed R.; Hall, F. Scott; Perona, Maria T. G.; Pistell, Paul J.; Lathia, Justin D.; Chigurupati, Srinivasulu; Becker, Kevin G.; Ladenheim, Bruce; Niklason, Laura E.; Uhl, George R; Cadet, Jean Lud; Mattson, Mark P.

    2010-01-01

    Because the olfactory system plays a major role in food consumption, and because “food addiction” and associated morbidities have reached epidemic proportions, we tested the hypothesis that dietary energy restriction can modify adverse effects of cocaine on behavior and olfactory cellular and molecular plasticity. Mice maintained on an alternate day fasting (ADF) diet exhibited increased baseline locomotion and increased cocaine-sensitized locomotion during cocaine conditioning, despite no ch...

  12. FMRP and dendritic local translation of αCaMKII mRNA are required for the structural plasticity underlying olfactory learning

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    Daroles, Laura; Gribaudo, Simona; Doulazmi, Mohamed; Scotto-Lomassese, Sophie; Dubacq, Caroline; Mandairon, Nathalie; Greer, Charles August; Didier, Anne; Trembleau, Alain; Caillé, Isabelle

    2015-01-01

    BackgroundIn the adult brain, structural plasticity allowing gain or loss of synapses remodels circuits to support learning. In Fragile X Syndrome (FXS), the absence of Fragile X Mental Retardation Protein (FMRP) leads to defects in plasticity and learning deficits. FMRP is a master regulator of local translation but its implication in learning-induced structural plasticity is unknown.MethodsUsing an olfactory learning task requiring adult-born olfactory bulb (OB) neurons and cell-specific ab...

  13. Mechanism of Notch Pathway Activation and Its Role in the Regulation of Olfactory Plasticity in Drosophila melanogaster.

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    Kidd, Simon; Lieber, Toby

    2016-01-01

    The neural plasticity of sensory systems is being increasingly recognized as playing a role in learning and memory. We have previously shown that Notch, part of an evolutionarily conserved intercellular signaling pathway, is required in adult Drosophila melanogaster olfactory receptor neurons (ORNs) for the structural and functional plasticity of olfactory glomeruli that is induced by chronic odor exposure. In this paper we address how long-term exposure to odor activates Notch and how Notch in conjunction with chronic odor mediates olfactory plasticity. We show that upon chronic odor exposure a non-canonical Notch pathway mediates an increase in the volume of glomeruli by a mechanism that is autonomous to ORNs. In addition to activating a pathway that is autonomous to ORNs, chronic odor exposure also activates the Notch ligand Delta in second order projection neurons (PNs), but this does not appear to require acetylcholine receptor activation in PNs. Delta on PNs then feeds back to activate canonical Notch signaling in ORNs, which restricts the extent of the odor induced increase in glomerular volume. Surprisingly, even though the pathway that mediates the increase in glomerular volume is autonomous to ORNs, nonproductive transsynaptic Delta/Notch interactions that do not activate the canonical pathway can block the increase in volume. In conjunction with chronic odor, the canonical Notch pathway also enhances cholinergic activation of PNs. We present evidence suggesting that this is due to increased acetylcholine release from ORNs. In regulating physiological plasticity, Notch functions solely by the canonical pathway, suggesting that there is no direct connection between morphological and physiological plasticity. PMID:26986723

  14. Notch is required in adult Drosophila sensory neurons for morphological and functional plasticity of the olfactory circuit.

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    Simon Kidd

    2015-05-01

    Full Text Available Olfactory receptor neurons (ORNs convey odor information to the central brain, but like other sensory neurons were thought to play a passive role in memory formation and storage. Here we show that Notch, part of an evolutionarily conserved intercellular signaling pathway, is required in adult Drosophila ORNs for the structural and functional plasticity of olfactory glomeruli that is induced by chronic odor exposure. Specifically, we show that Notch activity in ORNs is necessary for the odor specific increase in the volume of glomeruli that occurs as a consequence of prolonged odor exposure. Calcium imaging experiments indicate that Notch in ORNs is also required for the chronic odor induced changes in the physiology of ORNs and the ensuing changes in the physiological response of their second order projection neurons (PNs. We further show that Notch in ORNs acts by both canonical cleavage-dependent and non-canonical cleavage-independent pathways. The Notch ligand Delta (Dl in PNs switches the balance between the pathways. These data define a circuit whereby, in conjunction with odor, N activity in the periphery regulates the activity of neurons in the central brain and Dl in the central brain regulates N activity in the periphery. Our work highlights the importance of experience dependent plasticity at the first olfactory synapse.

  15. Identification and functional analysis of olfactory receptor family reveal unusual characteristics of the olfactory system in the migratory locust

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    Wang, Zhifeng; Yang, Pengcheng; Chen, Dafeng; Jiang, Feng; Li, Yan; Wang, Xianhui; Kang, Le

    2015-01-01

    Locusts represent the excellent model of insect olfaction because the animals are equipped with an unusual olfactory system and display remarkable density-dependent olfactory plasticity. However, information regarding receptor molecules involved in the olfactory perception of locusts is very limited. On the basis of genome sequence and antennal transcriptome of the migratory locust, we conduct the identification and functional analysis of two olfactory receptor families: odorant receptors (OR...

  16. Detection of explosives by olfactory sensory neurons.

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    Corcelli, Angela; Lobasso, Simona; Lopalco, Patrizia; Dibattista, Michele; Araneda, Ricardo; Peterlin, Zita; Firestein, Stuart

    2010-03-15

    The response of olfactory sensory neurons to TNT and RDX as well as to some volatile organic compounds present in the vapors of antipersonnel landmines has been studied both in the pig and in the rat. GC/MS analyses of different plastic components of six different kinds of landmines were performed in order to identify the components of the "perfume" of mines. Studies on rat olfactory mucosa were carried out with electro-olfactogram and calcium imaging techniques, while changes in the cyclic adenosine monophosphate (cAMP) levels following exposure to odorants and explosives were used as a criterion to evaluate the interaction of TNT and RDX with olfactory receptors in a preparation of isolated pig olfactory cilia. These studies indicate that chemical compounds associated with explosives and explosive devices can activate mammalian olfactory receptors. PMID:19913995

  17. Photoperiod mediated changes in olfactory bulb neurogenesis and olfactory behavior in male white-footed mice (Peromyscus leucopus.

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    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.

  18. Map Formation in the Olfactory Bulb by Axon Guidance of Olfactory Neurons

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    Benjamin Auffarth; Anders Lansner

    2011-01-01

    The organization of representations in the brain has been observed to locally reflect subspaces of inputs that are relevant to behavioral or perceptual feature combinations, such as in areas receptive to lower and higher-order features in the visual system. The early olfactory system developed highly plastic mechanisms and convergent evidence indicates that projections from primary neurons converge onto the glomerular level of the olfactory bulb (OB) to form a code composed of continuous spat...

  19. Loss of STOP protein impairs peripheral olfactory neurogenesis.

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    Karelle Benardais

    Full Text Available BACKGROUND: STOP (Stable Tubulin-Only Polypeptide null mice show behavioral deficits, impaired synaptic plasticity, decrease in synaptic vesicular pools and disturbances in dopaminergic transmission, and are considered a neurodevelopmental model of schizophrenia. Olfactory neurons highly express STOP protein and are continually generated throughout life. Experimentally-induced loss of olfactory neurons leads to epithelial regeneration within two months, providing a useful model to evaluate the role played by STOP protein in adult olfactory neurogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Immunocytochemistry and electron microscopy were used to study the structure of the glomerulus in the main olfactory bulb and neurogenesis in the neurosensorial epithelia. In STOP null mice, olfactory neurons showed presynaptic swellings with tubulovesicular profiles and autophagic-like structures. In olfactory and vomeronasal epithelia, there was an increase in neurons turnover, as shown by the increase in number of proliferating, apoptotic and immature cells with no changes in the number of mature neurons. Similar alterations in peripheral olfactory neurogenesis have been previously described in schizophrenia patients. In STOP null mice, regeneration of the olfactory epithelium did not modify these anomalies; moreover, regeneration resulted in abnormal organisation of olfactory terminals within the olfactory glomeruli in STOP null mice. CONCLUSIONS/SIGNIFICANCE: In conclusion, STOP protein seems to be involved in the establishment of synapses in the olfactory glomerulus. Our results indicate that the olfactory system of STOP null mice is a well-suited experimental model (1 for the study of the mechanism of action of STOP protein in synaptic function/plasticity and (2 for pathophysiological studies of the mechanisms of altered neuronal connections in schizophrenia.

  20. Olfactory Neuroblastoma: Diagnostic Difficulty

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    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

  1. Olfactory ensheathing cell tumor

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    Ippili Kaushal

    2009-01-01

    Full Text Available Olfactory ensheathing cells (OECs are found in the olfactory bulb and olfactory nasal mucosa. They resemble Schwann cells on light and electron microscopy, however, immunohistochemical staining can distinguish between the two. There are less than 30 cases of olfactory groove schwannomas reported in the literature while there is only one reported case of OEC tumor. We report an OEC tumor in a 42-year-old male and discuss the pathology and origin of this rare tumor.

  2. A subtype-specific critical period for neurogenesis in the postnatal development of mouse olfactory glomeruli.

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    Yasuko Kato

    Full Text Available Sensory input is essential for the normal development of sensory centers in the brain, such as the somatosensory, visual, auditory, and olfactory systems. Visual deprivation during a specific developmental stage, called the critical period, results in severe and irreversible functional impairments in the primary visual cortex. Olfactory deprivation in the early postnatal period also causes significant developmental defects in the olfactory bulb, the primary center for olfaction. Olfactory bulb interneurons are continuously generated from neural stem cells in the ventricular-subventricular zone, suggesting that the olfactory system has plasticity even in adulthood. Here, we investigated the effect of transient neonatal olfactory deprivation on the addition of interneurons to the glomerular layer of the adult mouse olfactory bulb. We found that the addition of one subtype of interneurons was persistently inhibited even after reopening the naris. BrdU pulse-chase experiments revealed that the neonatal olfactory deprivation predominantly affected an early phase in the maturation of this neuronal subtype in the olfactory bulb. Subjecting the mice to odor stimulation for 6 weeks after naris reopening resulted in significant recovery from the histological and functional defects caused by the olfactory deprivation. These results suggest that a subtype-specific critical period exists for olfactory bulb neurogenesis, but that this period is less strict and more plastic compared with the critical periods for other systems. This study provides new insights into the mechanisms of postnatal neurogenesis and a biological basis for the therapeutic effect of olfactory training.

  3. Olfactory bulb encoding during learning under anaesthesia

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    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

  4. Expression of polysialyltransferases (STX and PST) in adult rat olfactory bulb after an olfactory associative discrimination task.

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    Mione, J; Manrique, C; Duhoo, Y; Roman, F S; Guiraudie-Capraz, G

    2016-04-01

    Neuronal plasticity and neurogenesis occur in the adult hippocampus and in other brain structures such as the olfactory bulb and often involve the neural cell adhesion molecule NCAM. During an olfactory associative discrimination learning task, NCAM polysialylation triggers neuronal plasticity in the adult hippocampus. The PST enzyme likely modulates this polysialylation, but not STX, a second sialyltransferase. How the two polysialyltransferases are involved in the adult olfactory bulb remains unknown. We addressed this question by investigating the effect of olfactory associative learning on plasticity and neurogenesis. After a hippocampo-dependent olfactory associative task learning, we measured the expression of both PST and STX polysialyltransferases in the olfactory bulbs of adult rats using quantitative PCR. In parallel, immunohistochemistry was used to evaluate both NCAM polysialylation level and newly-born cells, with or without learning. After learning, no changes were observed neither in the expression level of PST and NCAM polysialylation, nor in STX gene expression level and newly-born cells number in the olfactory bulb. PMID:26844880

  5. Reorganization of neuronal circuits of the central olfactory system during postprandial sleep

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    Masahiro eYamaguchi

    2013-08-01

    Full Text Available Plastic changes in neuronal circuits often occur in association with specific behavioral states. In this review, we focus on an emerging view that neuronal circuits in the olfactory system are reorganized along the wake-sleep cycle. Olfaction is crucial to sustaining the animals’ life, and odor-guided behaviors have to be newly acquired or updated to successfully cope with a changing odor world. It is therefore likely that neuronal circuits in the olfactory system are highly plastic and undergo repeated reorganization in daily life. A remarkably plastic feature of the olfactory system is that newly generated neurons are continually integrated into neuronal circuits of the olfactory bulb (OB throughout life. New neurons in the OB undergo an extensive selection process, during which many are eliminated by apoptosis for the fine tuning of neuronal circuits. The life and death decision of new neurons occurs extensively during a short time window of sleep after food consumption (postprandial sleep, a typical daily olfactory behavior. We review recent studies that explain how olfactory information is transferred between the OB and the olfactory cortex (OC along the course of the wake-sleep cycle. Olfactory sensory input is effectively transferred from the OB to the OC during waking, while synchronized top-down inputs from the OC to the OB are promoted during the slow-wave sleep. We discuss possible neuronal circuit mechanisms for the selection of new neurons in the OB, which involves the encoding of olfactory sensory inputs and memory trace formation during waking and internally generated activities in the OC and OB during subsequent sleep. The plastic changes in the OB and OC are well coordinated along the course of olfactory behavior during wakefulness and postbehavioral rest and sleep. We therefore propose that the olfactory system provides an excellent model in which to understand behavioral state-dependent plastic mechanisms of the neuronal

  6. Linking adult olfactory neurogenesis to social behavior

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    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.

  7. Olfactory Signal Processing

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    Varshney, Kush R.; Varshney, Lav R.

    2014-01-01

    Olfaction, the sense of smell, has received scant attention from a signal processing perspective in comparison to audition and vision. In this paper, we develop a signal processing paradigm for olfactory signals based on new scientific discoveries including the psychophysics concept of olfactory white. We describe a framework for predicting the perception of odorant compounds from their physicochemical features and use the prediction as a foundation for several downstream processing tasks. We...

  8. the olfactory bulbectomized mouse

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    Fink, Katharina

    2010-01-01

    The bilateral ectomy of the olfactory bulb in rats and mice is an accepted animal model of depression. Because of its good predictive validity it is used to develop new antidepressants and to prove their effectiveness. After the olfactory bulbectomy, the animals show a certain pattern of changes in behaviour and in neurochemical, neuroendocrinological and neuroimmunological parameters. The leading parameter for the changes of behaviour in these animals is the locomotoric hyperactivity in the ...

  9. Ionotropic crustacean olfactory receptors.

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    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.

  10. Neurobiology of mammalian olfactory learning that occurs during sensitive periods

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    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].

  11. Neural correlates of olfactory processing in congenital blindness

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    Kupers, R; Beaulieu-Lefebvre, M; Schneider, F C;

    2011-01-01

    highly plastic and that blind individuals rely more on their sense of smell than the sighted do. The olfactory system in the blind is therefore likely to be susceptible to cross-modal changes similar to those observed for the tactile and auditory modalities. To test this hypothesis, we used functional...

  12. Adult Olfactory Bulb Neurogenesis.

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    Lledo, Pierre-Marie; Valley, Matt

    2016-01-01

    Most organisms use their olfactory system to detect and analyze chemical cues from the external world to guide essential behaviors. From worms to vertebrates, chemicals are detected by odorant receptors expressed by olfactory sensory neurons, which in vertebrates send an axon to the primary processing center called the olfactory bulb (OB). Within the OB, sensory neurons form excitatory synapses with projection neurons and with inhibitory interneurons. Thus, because of complex synaptic interactions, the output of a given projection neuron is determined not only by the sensory input, but also by the activity of local inhibitory interneurons that are regenerated throughout life in the process of adult neurogenesis. Herein, we discuss how it is optimized and why. PMID:27235474

  13. 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.

  14. Olfactory sensitivity in mammalian species.

    Science.gov (United States)

    Wackermannová, M; Pinc, L; Jebavý, L

    2016-07-18

    Olfaction enables most mammalian species to detect and discriminate vast numbers of chemical structures called odorants and pheromones. The perception of such chemical compounds is mediated via two major olfactory systems, the main olfactory system and the vomeronasal system, as well as minor systems, such as the septal organ and the Grueneberg ganglion. Distinct differences exist not only among species but also among individuals in terms of their olfactory sensitivity; however, little is known about the mechanisms that determine these differences. In research on the olfactory sensitivity of mammals, scientists thus depend in most cases on behavioral testing. In this article, we reviewed scientific studies performed on various mammalian species using different methodologies and target chemical substances. Human and non-human primates as well as rodents and dogs are the most frequently studied species. Olfactory threshold studies on other species do not exist with the exception of domestic pigs. Olfactory testing performed on seals, elephants, and bats focused more on discriminative abilities than on sensitivity. An overview of olfactory sensitivity studies as well as olfactory detection ability in most studied mammalian species is presented here, focusing on comparable olfactory detection thresholds. The basics of olfactory perception and olfactory sensitivity factors are also described. PMID:27070753

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

    OpenAIRE

    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

    2009-01-01

    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 Pe...

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

    Directory of Open Access Journals (Sweden)

    Matthieu Dacher

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.

  17. Olfactory consciousness and gamma oscillation couplings across the olfactory bulb, olfactory cortex and orbitofrontal cortex

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    KensakuMori

    2013-10-01

    Full Text Available The orbitofrontal cortex receives multi-modality sensory inputs, including olfactory input, and is thought to be involved in conscious perception of the olfactory image of objects. Generation of olfactory consciousness requires neuronal circuit mechanisms for the ‘binding’ of distributed neuronal activities, with each constituent neuron representing a specific component of an olfactory percept. The shortest neuronal pathway for odor signals to reach the orbitofrontal cortex is olfactory sensory neuron – olfactory bulb – olfactory cortex – orbitofrontal cortex, but other pathways exist, including transthalamic pathways. Here, we review studies on the structural organization and functional properties of the shortest pathway, and propose a model of neuronal circuit mechanisms underlying the temporal bindings of distributed neuronal activities in the olfactory cortex. We describe a hypothesis that suggests functional roles of gamma oscillations in the bindings. This hypothesis proposes that two types of projection neurons in the olfactory bulb, tufted cells and mitral cells, play distinct functional roles in bindings at neuronal circuits in the olfactory cortex: tufted cells provide specificity-projecting circuits which send odor information with early-onset fast gamma synchronization, while mitral cells give rise to dispersedly-projecting feed-forward binding circuits which transmit the response synchronization timing with later-onset slow gamma synchronization. This hypothesis also suggests a sequence of bindings in the olfactory cortex: a small-scale binding by the early-phase fast gamma synchrony of tufted cell inputs followed by a larger-scale binding due to the later-onset slow gamma synchrony of mitral cell inputs. We discuss that behavioral state, including wakefulness and sleep, regulates gamma oscillation couplings across the olfactory bulb, olfactory cortex, and orbitofrontal cortex.

  18. Olfactory threshold in Parkinson's disease.

    OpenAIRE

    Quinn, N P; M.N. Rossor; Marsden, C. D.

    1987-01-01

    Olfactory threshold to differing concentrations of amyl acetate was determined in 78 subjects with idiopathic Parkinson's disease and 40 age-matched controls. Impaired olfactory threshold (previously reported by others) was confirmed in Parkinsonian subjects compared with controls. There was no significant correlation between olfactory threshold and age, sex, duration of disease, or current therapy with levodopa or anticholinergic drugs. In a sub-group of 14 levodopa-treated patients with sev...

  19. 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.

  20. Learning to smell danger: acquired associative representation of threat in the olfactory cortex.

    Science.gov (United States)

    Li, Wen

    2014-01-01

    Neuroscience research over the past few decades has reached a strong consensus that the amygdala plays a key role in emotion processing. However, many questions remain unanswered, especially concerning emotion perception. Based on mnemonic theories of olfactory perception and in light of the highly associative nature of olfactory cortical processing, here I propose a sensory cortical model of olfactory threat perception (i.e., sensory-cortex-based threat perception): the olfactory cortex stores threat codes as acquired associative representations (AARs) formed via aversive life experiences, thereby enabling encoding of threat cues during sensory processing. Rodent and human research in olfactory aversive conditioning was reviewed, indicating learning-induced plasticity in the amygdala and the olfactory piriform cortex. In addition, as aversive learning becomes consolidated in the amygdala, the associative olfactory (piriform) cortex may undergo (long-term) plastic changes, resulting in modified neural response patterns that underpin threat AARs. This proposal thus brings forward a sensory cortical pathway to threat processing (in addition to amygdala-based processes), potentially accounting for an alternative mechanism underlying the pathophysiology of anxiety and depression. PMID:24778610

  1. Gap junctions in olfactory neurons modulate olfactory sensitivity

    Directory of Open Access Journals (Sweden)

    Zhang Chunbo

    2010-08-01

    Full Text Available Abstract Background One of the fundamental questions in olfaction is whether olfactory receptor neurons (ORNs behave as independent entities within the olfactory epithelium. On the basis that mature ORNs express multiple connexins, I postulated that gap junctional communication modulates olfactory responses in the periphery and that disruption of gap junctions in ORNs reduces olfactory sensitivity. The data collected from characterizing connexin 43 (Cx43 dominant negative transgenic mice OlfDNCX, and from calcium imaging of wild type mice (WT support my hypothesis. Results I generated OlfDNCX mice that express a dominant negative Cx43 protein, Cx43/β-gal, in mature ORNs to inactivate gap junctions and hemichannels composed of Cx43 or other structurally related connexins. Characterization of OlfDNCX revealed that Cx43/β-gal was exclusively expressed in areas where mature ORNs resided. Real time quantitative PCR indicated that cellular machineries of OlfDNCX were normal in comparison to WT. Electroolfactogram recordings showed decreased olfactory responses to octaldehyde, heptaldehyde and acetyl acetate in OlfDNCX compared to WT. Octaldehyde-elicited glomerular activity in the olfactory bulb, measured according to odor-elicited c-fos mRNA upregulation in juxtaglomerular cells, was confined to smaller areas of the glomerular layer in OlfDNCX compared to WT. In WT mice, octaldehyde sensitive neurons exhibited reduced response magnitudes after application of gap junction uncoupling reagents and the effects were specific to subsets of neurons. Conclusions My study has demonstrated that altered assembly of Cx43 or structurally related connexins in ORNs modulates olfactory responses and changes olfactory activation maps in the olfactory bulb. Furthermore, pharmacologically uncoupling of gap junctions reduces olfactory activity in subsets of ORNs. These data suggest that gap junctional communication or hemichannel activity plays a critical role in

  2. Map formation in the olfactory bulb by axon guidance of olfactory neurons

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    Benjamin Auffarth

    2011-10-01

    Full Text Available The organization of representations in the brain has been observed to locally reflect subspaces of inputsthat are relevant to behavioral or perceptual feature combinations, such as in areas receptiveto lower and higher-order features in the visual system. The early olfactory system developedhighly plastic mechanisms and convergent evidence indicates that projections from primaryneurons converge onto the glomerular level of the olfactory bulb (OB to form a code composed ofcontinuous spatial zones that are differentially active for particular physico–-chemical featurecombinations, some of which are known to trigger behavioral responses. In a model study of theearly human olfactory system, we derive a glomerular organization based on a set of real-world,biologically-relevant stimuli, a distribution of receptors that respond each to a set ofodorants of similar ranges of molecular properties, and a mechanism of axon guidance basedon activity. Apart from demonstrating activity-dependent glomeruli formation and reproducing therelationship of glomerular recruitment with concentration, it is shown that glomerular responsesreflect similarities of human odor category perceptions and that further, a spatial code providesa better correlation than a distributed population code. These results are consistent with evidenceof functional compartmentalization in the OB and could suggest a function for the bulb inencoding of perceptual dimensions.

  3. Digital Olfactory Technology

    Directory of Open Access Journals (Sweden)

    G. Krishna Chaitanya

    2013-01-01

    Full Text Available The technology has so far targeted mainly on senses of sight and sound.To further enhance the virtual reality experience and add another flavor to it,technology is now targeting on the sense of smell.As we already know that nose is used to smell. Smell is an underused sense in human-computer interaction.(HCI. In our daily lives, smell tells us whether food is safe to eat, if a fire is breaking out in the next room and so on.The application area of virtual reality is vast- from normal entertainment to the Internet and e-commerce application. With the Digital Olfactory Technology,the customer will be able to smell the product before buying it online.California-based Digiscents Inc. has developed the iSmell personal scent synthesizer in the year 2000, which  provides scent-enabled  web sites, emails, interactive games, on-line advertising ,and many more.The iSmell is a personal synthesizer that emits a broad range of fragrances. The iSmell Digital Olfactory Technology is a complete solution for the digitization ,broadcast and synthesis of smells to accompany all forms of media! iSmell is a plug-in computer accessory that contains a basic palette of scented oils from which a bouquet of different smells can be created.

  4. The olfactory transcriptomes of mice.

    Science.gov (United States)

    Ibarra-Soria, Ximena; Levitin, Maria O; Saraiva, Luis R; Logan, Darren W

    2014-09-01

    The olfactory (OR) and vomeronasal receptor (VR) repertoires are collectively encoded by 1700 genes and pseudogenes in the mouse genome. Most OR and VR genes were identified by comparative genomic techniques and therefore, in many of those cases, only their protein coding sequences are defined. Some also lack experimental support, due in part to the similarity between them and their monogenic, cell-specific expression in olfactory tissues. Here we use deep RNA sequencing, expression microarray and quantitative RT-PCR in both the vomeronasal organ and whole olfactory mucosa to quantify their full transcriptomes in multiple male and female mice. We find evidence of expression for all VR, and almost all OR genes that are annotated as functional in the reference genome, and use the data to generate over 1100 new, multi-exonic, significantly extended receptor gene annotations. We find that OR and VR genes are neither equally nor randomly expressed, but have reproducible distributions of abundance in both tissues. The olfactory transcriptomes are only minimally different between males and females, suggesting altered gene expression at the periphery is unlikely to underpin the striking sexual dimorphism in olfactory-mediated behavior. Finally, we present evidence that hundreds of novel, putatively protein-coding genes are expressed in these highly specialized olfactory tissues, and carry out a proof-of-principle validation. Taken together, these data provide a comprehensive, quantitative catalog of the genes that mediate olfactory perception and pheromone-evoked behavior at the periphery. PMID:25187969

  5. The olfactory transcriptomes of mice.

    Directory of Open Access Journals (Sweden)

    Ximena Ibarra-Soria

    2014-09-01

    Full Text Available The olfactory (OR and vomeronasal receptor (VR repertoires are collectively encoded by 1700 genes and pseudogenes in the mouse genome. Most OR and VR genes were identified by comparative genomic techniques and therefore, in many of those cases, only their protein coding sequences are defined. Some also lack experimental support, due in part to the similarity between them and their monogenic, cell-specific expression in olfactory tissues. Here we use deep RNA sequencing, expression microarray and quantitative RT-PCR in both the vomeronasal organ and whole olfactory mucosa to quantify their full transcriptomes in multiple male and female mice. We find evidence of expression for all VR, and almost all OR genes that are annotated as functional in the reference genome, and use the data to generate over 1100 new, multi-exonic, significantly extended receptor gene annotations. We find that OR and VR genes are neither equally nor randomly expressed, but have reproducible distributions of abundance in both tissues. The olfactory transcriptomes are only minimally different between males and females, suggesting altered gene expression at the periphery is unlikely to underpin the striking sexual dimorphism in olfactory-mediated behavior. Finally, we present evidence that hundreds of novel, putatively protein-coding genes are expressed in these highly specialized olfactory tissues, and carry out a proof-of-principle validation. Taken together, these data provide a comprehensive, quantitative catalog of the genes that mediate olfactory perception and pheromone-evoked behavior at the periphery.

  6. Activity-induced remodeling of olfactory bulb microcircuits revealed by monosynaptic tracing.

    Directory of Open Access Journals (Sweden)

    Benjamin R Arenkiel

    Full Text Available The continued addition of new neurons to mature olfactory circuits represents a remarkable mode of cellular and structural brain plasticity. However, the anatomical configuration of newly established circuits, the types and numbers of neurons that form new synaptic connections, and the effect of sensory experience on synaptic connectivity in the olfactory bulb remain poorly understood. Using in vivo electroporation and monosynaptic tracing, we show that postnatal-born granule cells form synaptic connections with centrifugal inputs and mitral/tufted cells in the mouse olfactory bulb. In addition, newly born granule cells receive extensive input from local inhibitory short axon cells, a poorly understood cell population. The connectivity of short axon cells shows clustered organization, and their synaptic input onto newborn granule cells dramatically and selectively expands with odor stimulation. Our findings suggest that sensory experience promotes the synaptic integration of new neurons into cell type-specific olfactory circuits.

  7. Olfactory receptor signaling.

    Science.gov (United States)

    Antunes, Gabriela; Simoes de Souza, Fabio Marques

    2016-01-01

    The guanine nucleotide protein (G protein)-coupled receptors (GPCRs) superfamily represents the largest class of membrane protein in the human genome. More than a half of all GPCRs are dedicated to interact with odorants and are termed odorant-receptors (ORs). Linda Buck and Richard Axel, the Nobel Prize laureates in physiology or medicine in 2004, first cloned and characterized the gene family that encode ORs, establishing the foundations to the understanding of the molecular basis for odor recognition. In the last decades, a lot of progress has been done to unravel the functioning of the sense of smell. This chapter gives a general overview of the topic of olfactory receptor signaling and reviews recent advances in this field. PMID:26928542

  8. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

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

    2011-01-01

    consequence of the environmental conditions olfactory receptor genes have explored during evolution. The association of odorant patterns with specific environmental or contextual situations makes their relationship semiotically triadic, due to the emergence of an interpretant capable of perceiving odorants as...

  9. The Olfactory Transcriptomes of Mice

    OpenAIRE

    Ibarra-Soria, Ximena; Levitin, Maria O.; Saraiva, Luis R.; Logan, Darren W.

    2014-01-01

    The olfactory (OR) and vomeronasal receptor (VR) repertoires are collectively encoded by 1700 genes and pseudogenes in the mouse genome. Most OR and VR genes were identified by comparative genomic techniques and therefore, in many of those cases, only their protein coding sequences are defined. Some also lack experimental support, due in part to the similarity between them and their monogenic, cell-specific expression in olfactory tissues. Here we use deep RNA sequencing, expression microarra...

  10. Olfactory dysfunction in Parkinson's disease.

    OpenAIRE

    Hawkes, C H; Shephard, B C; Daniel, S E

    1997-01-01

    OBJECTIVE: To evaluate olfactory function in Parkinson's disease. METHODS: A standardised odour identification test was used, together with an evoked potential assessment with hydrogen sulphide. In addition, histological analysis was performed on the olfactory bulbs of cadavers who died from Parkinson's disease. RESULTS: Over 70% of patients studied (71 of 96) were outside the 95% limit of normal on the identification test in an age matched sample and there was an unusual pattern of selective...

  11. The progress of olfactory transduction and biomimetic olfactory-based biosensors

    Institute of Scientific and Technical Information of China (English)

    WU ChunSheng; WANG LiJiang; ZHOU Jun; ZHAO LuHang; WANG Ping

    2007-01-01

    Olfaction is a very important sensation for all animals. Recently great progress has been made in the research of olfactory transduction. Especially the novel finding of the gene superfamily encoding olfactory receptors has led to rapid advances in olfactory transduction. These advances also promoted the research of biomimetic olfactory-based biosensors and some obvious achievements have been obtained due to their potential commercial prospects and promising industrial applications. This paper briefly introduces the biological basis of olfaction, summarizes the progress of olfactory signal transduction in the olfactory neuron, the olfactory bulb and the olfactory cortex, outlines the latest developments and applications of biomimetic olfactory-based biosensors. Finally, the olfactory biosensor based on light addressable potentiometric sensor (LAPS) is addressed in detail based on our recent work and the research trends of olfactory biosensors in future are discussed.

  12. How does long-term odor deprivation affect the olfactory capacity of adult mice?

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    Coppola David M

    2010-05-01

    Full Text Available Abstract Background Unilateral naris occlusion (UNO has been the most common method of effecting stimulus deprivation in studies of olfactory plasticity. However, despite the large corpus on the effects of this manipulation, dating back to the 19th century, little is known about its behavioral sequela. Here we report the results of standard olfactory habituation and discrimination studies on adult mice that had undergone perinatal UNO followed by adult contralateral olfactory bulbectomy (bulb-x. Methods The olfactory performance of UNO mice was compared to matched controls that had unilateral bulb-x but open nares. Both habituation and discrimination (operant experiments employed a protocol in which after successful dishabituation or discrimination to dilute individual odors (A = 0.01% isoamyl acetate; B = 0.01% ethyl butyrate; each v/v in mineral oil, mice were challenged with a single odor versus a mixture comparison (A vs. A + B. In a series of tests the volume portion of Odor B in the mixture was systematically decreased until dishabituation or discrimination thresholds were reached. Results For the habituation experiment, UNOs (n = 10 and controls (n = 9 dishabituated to a 10% mixture of Odor B in Odor A after being habituated to A alone, while both groups failed to show differential responding to a 2% mixture of B in A. However, the UNO group's increased investigation durations for the 2% mixture approached significance (p Conclusions Adult mice relying on an olfactory system deprived of odor by naris occlusion from near the time of birth display enhanced olfactory capacity compared to control mice. This counterintuitive result suggests that UNO is neither an absolute method of deprivation nor does it diminish olfactory capabilities. Enhanced olfactory capacity, as observed in the current study, that is a consequence of deprivation, is consistent with recent molecular and physiological evidence that stimulus deprivation triggers

  13. Culture of Mouse Olfactory Sensory Neurons

    OpenAIRE

    Gong, Qizhi

    2012-01-01

    Olfactory sensory neurons, located in the nasal epithelium, detect and transmit odorant information to the central nervous system. This requires that these neurons form specific neuronal connections within the olfactory bulb and express receptors and signaling molecules specific for these functions. This protocol describes a primary olfactory sensory neuron culture technique that allows in vitro investigation of olfactory sensory neuron differentiation, axon outgrowth, odorant receptor expres...

  14. Neuronal organization of olfactory bulb circuits

    OpenAIRE

    Shin eNagayama; Ryota eHomma; Fumiaki eImamura

    2014-01-01

    Olfactory sensory neurons extend their axons solely to the olfactory bulb, which is dedicated to odor information processing. The olfactory bulb is divided into multiple layers, with different types of neurons found in each of the layers. Therefore, neurons in the olfactory bulb have conventionally been categorized based on the layers in which their cell bodies are found; namely, juxtaglomerular cells in the glomerular layer, tufted cells in the external plexiform layer, mitral cells in the...

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

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    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.

  16. Olfactory dysfunction in patients with multiple sclerosis.

    Science.gov (United States)

    Li, Li-Min; Yang, Li-Na; Zhang, Lin-Jie; Fu, Ying; Li, Ting; Qi, Yuan; Wang, Jing; Zhang, Da-Qi; Zhang, Ningnannan; Liu, Jingchun; Yang, Li

    2016-06-15

    Association of changes in olfactory-related structures with olfactory function in patients with multiple sclerosis (MS) is not well understood. We used a T&T olfactometer test kit to evaluate olfactory function in 26 patients with MS and 26 age- and sex-matched healthy controls (HC). Then, Brain MRI were performed and olfactory-related structures were analyzed in these subjects. Olfactory detection and recognition threshold were significantly higher in the MS group, interestingly olfactory recognition threshold positively correlated with expanded disability status scale scores in these patients. Olfactory bulb (OB) volume reduced in patients with olfactory dysfunction (ODF). At the same time, reductions in gray matter (GM) volume were observed in the parahippocampal gyrus (PCG), amygdala, piriform cortex, and inferior frontal gyrus in patients with MS compared to HC. Atrophy of the PCG was more obvious in patients with ODF than patients without ODF and the PCG volume correlated with the olfactory recognition threshold, while no difference was found in fractional anisotropy values of tract-based spatial statistics analysis in the two groups. Olfactory function in patients with MS tends to become gradually more impaired with disability aggravation. Decreases in the volume of the OB and olfactory-related GM might provide valuable information about disease status in patients with MS with olfactory impairment. PMID:27206870

  17. Ablation of mouse adult neurogenesis alters olfactory bulb structure and olfactory fear conditioning

    Directory of Open Access Journals (Sweden)

    Matthew Valley

    2009-11-01

    Full Text Available Adult neurogenesis replenishes olfactory bulb (OB interneurons throughout the life of most mammals, yet during this constant fl ux it remains unclear how the OB maintains a constant structure and function. In the mouse OB, we investigated the dynamics of turnover and its impact on olfactory function by ablating adult neurogenesis with an x-ray lesion to the subventricular zone (SVZ. Regardless of the magnitude of the lesion to the SVZ, we found no change in the survival of young adult born granule cells (GCs born after the lesion, and a gradual decrease in the population of GCs born before the lesion. After a lesion producing a 96% reduction of incoming adult born GCs to the OB, we found a diminished behavioral fear response to conditioned odor cues but not to audio cues. Interestingly, despite this behavioral defi cit and gradual anatomical changes, we found no electrophysiological changes in the GC population assayed in vivo through dendro-dendritic synaptic plasticity and odor-evoked local fi eld potential oscillations. These data indicate that turnover in the granule cell layer is generally decoupled from the rate of adult neurogenesis, and that OB adult neurogenesis plays a role in a wide behavioral system extending beyond the OB.

  18. Monoallelic expression of olfactory receptors.

    Science.gov (United States)

    Monahan, Kevin; Lomvardas, Stavros

    2015-01-01

    The sense of smell collects vital information about the environment by detecting a multitude of chemical odorants. Breadth and sensitivity are provided by a huge number of chemosensory receptor proteins, including more than 1,400 olfactory receptors (ORs). Organizing the sensory information generated by these receptors so that it can be processed and evaluated by the central nervous system is a major challenge. This challenge is overcome by monogenic and monoallelic expression of OR genes. The single OR expressed by each olfactory sensory neuron determines the neuron's odor sensitivity and the axonal connections it will make to downstream neurons in the olfactory bulb. The expression of a single OR per neuron is accomplished by coupling a slow chromatin-mediated activation process to a fast negative-feedback signal that prevents activation of additional ORs. Singular OR activation is likely orchestrated by a network of interchromosomal enhancer interactions and large-scale changes in nuclear architecture. PMID:26359778

  19. 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.

  20. How to escape from haller's rule: Olfactory system complexity in small and large Trichogramma evanescens parasitic wasps.

    Science.gov (United States)

    van der Woude, Emma; Smid, Hans M

    2016-06-15

    While Haller's rule states that small animals have relatively larger brains, minute Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) parasitic wasps scale brain size linearly with body size. This linear brain scaling allows them to decrease brain size beyond the predictions of Haller's rule, and is facilitated by phenotypic plasticity in brain size. In the present study we addressed whether this plasticity resulted in adaptations to the complexity of the morphology of the olfactory system of small and large T. evanescens. We used confocal laser scanning microscopy to compare size and number of glomeruli in the antennal lobe in the brain, and scanning electron microscopy to compare length and number of olfactory sensilla on the antennae. The results show a similar level of complexity of the olfactory system morphology of small and large wasps. Wasps with a similar genotype but very different brain and body size have similarly sized olfactory sensilla and most of them occur in equal numbers on the antennae. Small and large wasps also have a similar number of glomeruli in the antennal lobe. Glomeruli in small brains are, however, smaller in both absolute and relative volume. These similarities between small and large wasps may indicate that plasticity in brain size does not require plasticity in the gross morphology of the olfactory system. It may be vital for wasps of all sizes to have a large number of olfactory receptor types, to maintain olfactory precision in their search for suitable hosts, and consequently maintain their reproductive success and Darwinian fitness. J. Comp. Neurol. 524:1876-1891, 2016. © 2015 Wiley Periodicals, Inc. PMID:26560192

  1. The impact of adult neurogenesis on olfactory bulb circuits and computations.

    Science.gov (United States)

    Lepousez, Gabriel; Valley, Matthew T; Lledo, Pierre-Marie

    2013-01-01

    Modern neuroscience has demonstrated how the adult brain has the ability to profoundly remodel its neurons in response to changes in external stimuli or internal states. However, adult brain plasticity, although possible throughout life, remains restricted mostly to subcellular levels rather than affecting the entire cell. New neurons are continuously generated in only a few areas of the adult brain-the olfactory bulb and the dentate gyrus-where they integrate into already functioning circuitry. In these regions, adult neurogenesis adds another dimension of plasticity that either complements or is redundant to the classical molecular and cellular mechanisms of plasticity. This review extracts clues regarding the contribution of adult-born neurons to the different circuits of the olfactory bulb and specifically how new neurons participate in existing computations and enable new computational functions. PMID:23190074

  2. Olfactory discrimination in the western lowland gorilla, Gorilla gorilla gorilla.

    Science.gov (United States)

    Hepper, Peter G; Wells, Deborah L

    2012-04-01

    The olfactory abilities of great apes have been subject to little empirical investigation, save for a few observational reports. This study, using an habituation/dishabituation task, provides experimental evidence for a core olfactory ability, namely, olfactory discrimination, in the gorilla. In Experiment 1, six zoo-housed western lowland gorillas were individually presented with the same odour on four trials, and with a novel odour on the fifth trial. Odours (almond and vanilla) were presented on plastic balls, and behavioural responses of sniffing and chewing/licking the balls were recorded. A second experiment presented the same odour on four trials and no odour on the fifth to examine whether any dishabituation was due to the presence of a new odour or the absence of the familiar odour. Gorillas habituated their behaviour with repeated presentation of the same odour, but dishabituated, i.e. increased sniffing and chewing/licking, when presented with the novel odour. No dishabituation was noted when using water as the stimulus across all trials or when used as the novel odour. Overall, results show that gorillas are able to discriminate between odours. PMID:22261746

  3. Generalized plasticity

    CERN Document Server

    Yu, Mao-Hong

    2006-01-01

    Dealing with the plasticity of materials and structures, this book is an expansion of the "Unified Strength Theory to Plasticity Theory", leading to a unified treatment of metal plasticity and plasticity of geomaterials. It includes the metal plasticity for Tresca materials, Huber-von-Mises materials and twin-shear materials.

  4. Plastic Surgery

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word " ...

  5. 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

  6. Plasticity theory

    CERN Document Server

    Lubliner, Jacob

    2008-01-01

    The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

  7. A 3’UTR Pumilio binding element directs translational activation in olfactory sensory neurons

    OpenAIRE

    Kaye, Julia A.; Rose, Natalie C.; Goldsworthy, Brett; Goga, Andrei; L'Etoile, Noelle D.

    2009-01-01

    Prolonged stimulation leads to specific and stable changes in an animal’s behavior. In interneurons, this plasticity requires spatial and temporal control of neuronal protein synthesis. Whether such translational control occurs in sensory neurons is not known. Adaptation of the AWC olfactory sensory neurons of C. elegans requires the cGMP-dependent protein kinase EGL-4. Here we show that the PUF FBF-1 is required in the adult AWC for adaptation and in the odor-adapted animal, increases transl...

  8. Dopaminergic modulation of synaptic transmission and neuronal activity patterns in the zebrafish homolog of olfactory cortex

    OpenAIRE

    Schärer, Yan-Ping Zhang; Shum, Jennifer; Moressis, Anastasios; Friedrich, Rainer W.

    2012-01-01

    Dopamine (DA) is an important modulator of synaptic transmission and plasticity that is causally involved in fundamental brain functions and dysfunctions. We examined the dopaminergic modulation of synaptic transmission and sensory responses in telencephalic area Dp of zebrafish, the homolog of olfactory cortex. By combining anatomical tracing and immunohistochemistry, we detected no DA neurons in Dp itself but long-range dopaminergic input from multiple other brain areas. Whole-cell recordin...

  9. Dopaminergic modulation of synaptic transmission and neuronal activity patterns in the zebrafish homolog of olfactory cortex

    OpenAIRE

    Friedrich, Rainer W.

    2012-01-01

    Dopamine (DA) is an important modulator of synaptic transmission and plasticity that is causally involved in fundamental brain functions and dysfunctions. We examined the dopaminergic modulation of synaptic transmission and sensory responses in telencephalic area Dp of zebrafish, the homologue of olfactory cortex. By combining anatomical tracing and immunohistochemistry, we detected no DA neurons in Dp itself but long-range dopaminergic input from multiple other brain areas. Whole-cell record...

  10. Olfactory Jump Reflex Habituation in Drosophila and Effects of Classical Conditioning Mutations

    OpenAIRE

    Asztalos, Zoltan; Arora, Neeraj; Tully, Tim

    2007-01-01

    Habituation is a nonassociative learning mechanism, in which an initial response toward repeated stimuli gradually wanes. This is amongst the simplest and most widespread forms of behavioral plasticity. So far, neither the underlying molecular mechanisms nor the precise neural networks of habituation are well understood. We have developed a novel paradigm to quantify habituation of the olfactory jump reflex in Drosophila. We present data demonstrating several behavioral properties of this phe...

  11. Preliminary Modeling and Simulation Study on Olfactory Cell Sensation

    International Nuclear Information System (INIS)

    This paper introduced olfactory sensory neuron's whole-cell model with a concrete voltage-gated ionic channels and simulation. Though there are many models in olfactory sensory neuron and olfactory bulb, it remains uncertain how they express the logic of olfactory information processing. In this article, the olfactory neural network model is also introduced. This model specifies the connections among neural ensembles of the olfactory system. The simulation results of the neural network model are consistent with the observed olfactory biological characteristics such as 1/f-type power spectrum and oscillations.

  12. Neuropeptide Y in the olfactory microvillar cells.

    Science.gov (United States)

    Montani, Giorgia; Tonelli, Simone; Elsaesser, Rebecca; Paysan, Jacques; Tirindelli, Roberto

    2006-07-01

    This paper examines a possible role of microvillar cells in coordinating cell death and regeneration of olfactory epithelial neurons. The olfactory neuroepithelium of mammals is a highly dynamic organ. Olfactory neurons periodically degenerate by apoptosis and as a consequence of chemical or physical damage. To compensate for this loss of cells, the olfactory epithelium maintains a lifelong ability to regenerate from a pool of resident multipotent stem cells. To assure functional continuity and histological integrity of the olfactory epithelium over a period of many decades, apoptosis and regeneration require to be precisely coordinated. Among the factors that have been implicated in mediating this regulation is the neuropeptide Y (NPY). Knockout mice that lack functional expression of this neurogenic peptide show defects in embryonic development of the olfactory epithelium and in its ability to regenerate in the adult. Here we show that, in postnatal olfactory epithelia, NPY is exclusively expressed by a specific population of microvillar cells. We previously characterized these cells as a novel type of putative chemosensory cells, which are provided with a phosphatidyl-inositol-mediated signal transduction cascade. Our findings allow for the first time to suggest that microvillar cells are involved in connecting apoptosis to neuronal regeneration by stimulus-induced release of NPY. PMID:16800866

  13. THE OLFACTORY SYSTEM REGULATES ACUTE MOUNTAIN SICKNESS

    Directory of Open Access Journals (Sweden)

    Savitha Nagabhushan

    2009-05-01

    Full Text Available OBJECTIVE:Hyperventilation is the first response to hypoxia in high altitude (HA. Our study on rats was designed to establish an integrated hypothesis to include hyperventilation, increased activity of hypothalamicpituitary-adrenocortical axis (HPA in response to initial exposure to hypoxia and failure of adaptation to stress in olfactory bulbectomised rats. .METHODS:Albino rats whose olfactory lobes were removed were subjected to hypoxia and hypothermic conditions. Blood and urine samples were collected at various stages to measure biochemical parameters. Rats whose olfactory systems were intact were used as controls.RESULTS:The results suggested that the olfactory system regulated pituitary function and that in rats whose olfactory lobes were removed failed to adapt to the stress created by hypoxia and hypothermia.CONCLUSIONS:Acute Mountain Sickness (AMS is a type of stress. Normal rats when subjected to stress such as AMSare able to adapt. This adaptation is lost when the olfactory bulbs are removed. It is postulated that serotonin receptors in the hypothalamus, through the splanchnic pathway regulate stress. This mechanism is independent of ACTH – Cortisol feed back system. Perhaps irregular and rapid respiratory rhythm simulates physiological Olfactory Bulbectomy during rapid climbing and AMS manifests as a failure of stress adaptation.

  14. Neuronal organization of olfactory bulb circuits

    Directory of Open Access Journals (Sweden)

    Shin eNagayama

    2014-09-01

    Full Text Available Olfactory sensory neurons extend their axons solely to the olfactory bulb, which is dedicated to odor information processing. The olfactory bulb is divided into multiple layers, with different types of neurons found in each of the layers. Therefore, neurons in the olfactory bulb have conventionally been categorized based on the layers in which their cell bodies are found; namely, juxtaglomerular cells in the glomerular layer, tufted cells in the external plexiform layer, mitral cells in the mitral cell layer, and granule cells in the granule cell layer. More recently, numerous studies have revealed the heterogeneous nature of each of these cell types, allowing them to be further divided into subclasses based on differences in morphological, molecular, and electrophysiological properties. In addition, technical developments and advances have resulted in an increasing number of studies regarding cell types other than the conventionally categorized ones described above, including short-axon cells and adult-generated interneurons. Thus, the expanding diversity of cells in the olfactory bulb is now being acknowledged. However, our current understanding of olfactory bulb neuronal circuits is mostly based on the conventional and simplest classification of cell types. Few studies have taken neuronal diversity into account for understanding the function of the neuronal circuits in this region of the brain. This oversight may contribute to the roadblocks in developing more precise and accurate models of olfactory neuronal networks. The purpose of this review is therefore to discuss the expanse of existing work on neuronal diversity in the olfactory bulb up to this point, so as to provide an overall picture of the olfactory bulb circuit.

  15. Clinical diagnosis and treatment of olfactory meningioma

    International Nuclear Information System (INIS)

    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)

  16. Accessory Olfactory Bulb Function is Modulated by Input from the Main Olfactory Epithelium

    OpenAIRE

    Slotnick, Burton; Restrepo, Diego; Schellinck, Heather; Archbold, Georgina; Price, Stephen; Lin, Weihong

    2010-01-01

    While it is now established that sensory neurons in both the main olfactory epithelium and the vomeronasal organ may be activated by both general and pheromonal odorants, it remains unclear what initiates sampling by the VNO. Anterograde transport of wheat germ agglutinin-horseradish peroxidase was used to determine that adequate intranasal syringing with zinc sulfate interrupted all inputs to the main olfactory bulb but left intact those to the accessory olfactory bulb. Adult male treated mi...

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

    International Nuclear Information System (INIS)

    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 (201Tl) administration has been safely used to assess the direct pathway to the brain via the nose in healthy volunteers with a normal olfactory threshold. 201Tl 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 201Tl olfacto-scintigraphy for the exclusion of candidates in a clinical trial to assess the usefulness of nasal administration of IGF-I. (author)

  18. BDNF over-expression increases olfactory bulb granule cell dendritic spine density in vivo.

    Science.gov (United States)

    McDole, B; Isgor, C; Pare, C; Guthrie, K

    2015-09-24

    Olfactory bulb granule cells (GCs) are axon-less, inhibitory interneurons that regulate the activity of the excitatory output neurons, the mitral and tufted cells, through reciprocal dendrodendritic synapses located on GC spines. These contacts are established in the distal apical dendritic compartment, while GC basal dendrites and more proximal apical segments bear spines that receive glutamatergic inputs from the olfactory cortices. This synaptic connectivity is vital to olfactory circuit function and is remodeled during development, and in response to changes in sensory activity and lifelong GC neurogenesis. Manipulations that alter levels of the neurotrophin brain-derived neurotrophic factor (BDNF) in vivo have significant effects on dendritic spine morphology, maintenance and activity-dependent plasticity for a variety of CNS neurons, yet little is known regarding BDNF effects on bulb GC spine maturation or maintenance. Here we show that, in vivo, sustained bulbar over-expression of BDNF in transgenic mice produces a marked increase in GC spine density that includes an increase in mature spines on their apical dendrites. Morphometric analysis demonstrated that changes in spine density were most notable in the distal and proximal apical domains, indicating that multiple excitatory inputs are potentially modified by BDNF. Our results indicate that increased levels of endogenous BDNF can promote the maturation and/or maintenance of dendritic spines on GCs, suggesting a role for this factor in modulating GC functional connectivity within adult olfactory circuitry. PMID:26211445

  19. Brief predator sound exposure elicits behavioral and neuronal long-term sensitization in the olfactory system of an insect

    DEFF Research Database (Denmark)

    Anton, S.; Evengaard, K.; Barrozo, R. B.;

    2011-01-01

    later in the same way as exposure to the sex pheromone itself. The observed behavioral modification is accompanied by an increase in the sensitivity of olfactory neurons in the antennal lobe. Our data provide thus evidence for cross-modal experience-dependent plasticity not only on the behavioral level...... behavioral and central nervous level. Here we show that this effect is not confined to the same sensory modality: the sensitivity of olfactory neurons can also be modulated by exposure to a different sensory stimulus, i.e., a pulsed stimulus mimicking echolocating sounds from attacking insectivorous bats. We...... tested responses of preexposed male moths in a walking bioassay and recorded from neurons in the primary olfactory center, the antennal lobe. We show that brief exposure to a bat call, but not to a behaviorally irrelevant tone, increases the behavioral sensitivity of male moths to sex pheromone 24 h...

  20. Cladistic analysis of olfactory and vomeronasal systems

    Directory of Open Access Journals (Sweden)

    Alino eMartinez-Marcos

    2011-01-01

    Full Text Available 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 sphericus 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.

  1. Cladistic analysis of olfactory and vomeronasal systems

    OpenAIRE

    Alino Martinez-Marcos

    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...

  2. Olfactory bulb habituation to odor stimuli

    OpenAIRE

    Chaudhury, Dipesh; Manella, Laura; Arellanos, Adolfo; Escanilla, Olga; Cleland, Thomas A.; Linster, Christiane

    2010-01-01

    Habituation is a simple form of memory, yet its neurobiological mechanisms are only beginning to be understood in mammals. In the olfactory system, the neural correlates of habituation at a fast experimental timescale involving very short intertrial intervals (tens of seconds) have been shown to depend on synaptic adaptation in olfactory cortex. In contrast, behavioral habituation to odorants on a longer timescale with intertrial intervals of several minutes depends on processes in the olfact...

  3. 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...

  4. Odorant Category Profile Selectivity of Olfactory Cortex

    OpenAIRE

    Yoshida, Ikue; Mori, Kensaku

    2007-01-01

    The olfactory cortex receives converging axonal inputs from many mitral and tufted cells in the olfactory bulb. Recent studies indicate that single cortical neurons integrate signals from diverse odorants. However, there remains a basic question, namely, the signals from which kinds of odorants are integrated by the individual cortical neurons? The present study examined the possibility that some cortical neurons integrate signals from distinct component odorants of natural foods because indi...

  5. Olfactory metaphors in the online environment

    OpenAIRE

    Alina Ţenescu

    2015-01-01

    The main objective of this paper is to analyze the main aspects of the olfactory metaphor in online perfume reviews and to identify its main characteristics in the non-specialized perfume discourse. Using as a starting point the approach whose overall view is guided by conceptual metaphor theory, we will identify, analyze and classify the main elements of the metaphorical schema associated with the olfactory metaphor related to fragrance perception and description. We will illustrate this cat...

  6. 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.

  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. PMID:23259951

  8. Neurotoxic Effects of Dichlorophenyl Methylsulphones Related to Olfactory Mucosal Lesions

    OpenAIRE

    Carlsson, Carina

    2003-01-01

    This thesis deals with the highly potent olfactory mucosa toxicant 2,6-dichlorophenyl methylsulphone (2,6-diClPh-MeSO2) and its non-toxic 2,5-chlorinated isomer (2,5-diClPh-MeSO2). In mice, both substances bind firmly in the olfactory mucosa and the olfactory bulb, which are important components of the sensory system. The 2,6-isomer induces olfactory mucosal necrosis with permanent loss of olfactory neuroepithelium and olfactory nerves. A major objective was to clarify the cause of this isome...

  9. Dopaminergic modulation of bulbofugal projections in the rat olfactory tubercle.

    Science.gov (United States)

    Inokuchi, A; Mooney, K E; Snow, J B

    1987-01-01

    Neuronal activities following olfactory bulb electrical stimulation were examined before and after administration of dopamine and dopamine antagonist in the rat olfactory tubercle. The inhibitory response to olfactory bulb stimulation was attenuated by systemic haloperidol administration, but the excitatory response to olfactory bulb stimulation rarely was modulated. Topical application of dopamine by iontophoresis extended the duration of inhibition in 56% of the neurons sampled and diminished it in 25%; the excitatory response was modulated in 42% of neurons, most of which were attenuated. These findings suggest that dopamine in the olfactory tubercle could be involved in modulations of neuronal activities related to olfactory transduction. PMID:2820257

  10. 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

    OpenAIRE

    ElenaV.Ignatieva; VictorG.Levitsky; NikolayA.Kolchanov

    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 re...

  11. Plastic Bronchitis

    OpenAIRE

    Quysner, Annie; Surani, Salim; Roberts, Daniel

    2011-01-01

    Plastic bronchitis is not yet well understood. There have been less than 500 reported cases in adults worldwide. This patient presented with a one month history of productive sputum consisting of bronchial casts resulting in a diagnosis of plastic bronchitis. [West J Emerg Med. 2011;12(1):118-119.

  12. 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.

    2016-01-01

    Objective 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 Study Design An in vivo study using a transgenic mouse model Setting Research laboratory Subjects and Methods To study the impact of chronic inflammation on the olfactory system, a transgenic mouse model of chronic rhinosinusitis (CRS)-associated olfactory loss was utilized (IOI mouse), expressing TNF-α in a temporally-controlled fashion specifically 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 equal number of control group. Results Compared to non-treated IOI mice, Etanercept -treated IOI mice showed significantly improved EOG responses after 2 weeks (p<0.001). After 8 weeks of induced inflammation, there was massive loss of olfactory epithelium and no EOG response in non-treated IOI mice. However, in Etanercept - treated mice, regeneration of olfactory epithelium was observed. Conclusion 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. PMID:26932943

  13. Cholecystokinin: an excitatory modulator of mitral/tufted cells in the mouse olfactory bulb.

    Directory of Open Access Journals (Sweden)

    Jie Ma

    Full Text Available Cholecystokinin (CCK is widely distributed in the brain as a sulfated octapeptide (CCK-8S. In the olfactory bulb, CCK-8S is concentrated in two laminae: an infraglomerular band in the external plexiform layer, and an inframitral band in the internal plexiform layer (IPL, corresponding to somata and terminals of superficial tufted cells with intrabulbar projections linking duplicate glomerular maps of olfactory receptors. The physiological role of CCK in this circuit is unknown. We made patch clamp recordings of CCK effects on mitral cell spike activity in mouse olfactory bulb slices, and applied immunohistochemistry to localize CCKB receptors. In cell-attached recordings, mitral cells responded to 300 nM-1 µM CCK-8S by spike excitation, suppression, or mixed excitation-suppression. Antagonists of GABAA and ionotropic glutamate receptors blocked suppression, but excitation persisted. Whole-cell recordings revealed that excitation was mediated by a slow inward current, and suppression by spike inactivation or inhibitory synaptic input. Similar responses were elicited by the CCKB receptor-selective agonist CCK-4 (1 µM. Excitation was less frequent but still occurred when CCKB receptors were blocked by LY225910, or disrupted in CCKB knockout mice, and was also observed in CCKA knockouts. CCKB receptor immunoreactivity was detected on mitral and superficial tufted cells, colocalized with Tbx21, and was absent from granule cells and the IPL. Our data indicate that CCK excites mitral cells postsynaptically, via both CCKA and CCKB receptors. We hypothesize that extrasynaptic CCK released from tufted cell terminals in the IPL may diffuse to and directly excite mitral cell bodies, creating a positive feedback loop that can amplify output from pairs of glomeruli receiving sensory inputs encoded by the same olfactory receptor. Dynamic plasticity of intrabulbar projections suggests that this could be an experience-dependent amplification mechanism for

  14. A 3’UTR Pumilio binding element directs translational activation in olfactory sensory neurons

    Science.gov (United States)

    Kaye, Julia A.; Rose, Natalie C.; Goldsworthy, Brett; Goga, Andrei; L'Etoile, Noelle D.

    2014-01-01

    Summary Prolonged stimulation leads to specific and stable changes in an animal’s behavior. In interneurons, this plasticity requires spatial and temporal control of neuronal protein synthesis. Whether such translational control occurs in sensory neurons is not known. Adaptation of the AWC olfactory sensory neurons of C. elegans requires the cGMP-dependent protein kinase EGL-4. Here we show that the PUF FBF-1 is required in the adult AWC for adaptation and in the odor-adapted animal, increases translation from the egl-4 3’ UTR. Further, the PUF protein may localize translation near the sensory cilia and cell body. Although the RNA-binding PUF proteins have been shown to promote plasticity in development by temporally and spatially repressing translation; this work reveals that in the adult nervous system, they can work in a different way to promote experience-dependent plasticity by activating translation in response to environmental stimulation. PMID:19146813

  15. A 3'UTR pumilio-binding element directs translational activation in olfactory sensory neurons.

    Science.gov (United States)

    Kaye, Julia A; Rose, Natalie C; Goldsworthy, Brett; Goga, Andrei; L'Etoile, Noelle D

    2009-01-15

    Prolonged stimulation leads to specific and stable changes in an animal's behavior. In interneurons, this plasticity requires spatial and temporal control of neuronal protein synthesis. Whether such translational control occurs in sensory neurons is not known. Adaptation of the AWC olfactory sensory neurons of C. elegans requires the cGMP-dependent protein kinase EGL-4. Here, we show that the RNA-binding PUF protein FBF-1 is required in the adult AWC for adaptation. In the odor-adapted animal, it increases translation via binding to the egl-4 3' UTR. Further, the PUF protein may localize translation near the sensory cilia and cell body. Although the RNA-binding PUF proteins have been shown to promote plasticity in development by temporally and spatially repressing translation, this work reveals that in the adult nervous system, they can work in a different way to promote experience-dependent plasticity by activating translation in response to environmental stimulation. PMID:19146813

  16. Canine olfactory ensheathing cells from the olfactory mucosa can be engineered to produce active chondroitinase ABC.

    Science.gov (United States)

    Carwardine, Darren; Wong, Liang-Fong; Fawcett, James W; Muir, Elizabeth M; Granger, Nicolas

    2016-08-15

    A multitude of factors must be overcome following spinal cord injury (SCI) in order to achieve clinical improvement in patients. It is thought that by combining promising therapies these diverse factors could be combatted with the aim of producing an overall improvement in function. Chondroitin sulphate proteoglycans (CSPGs) present in the glial scar that forms following SCI present a significant block to axon regeneration. Digestion of CSPGs by chondroitinase ABC (ChABC) leads to axon regeneration, neuronal plasticity and functional improvement in preclinical models of SCI. However, the enzyme activity decays at body temperature within 24-72h, limiting the translational potential of ChABC as a therapy. Olfactory ensheathing cells (OECs) have shown huge promise as a cell transplant therapy in SCI. Their beneficial effects have been demonstrated in multiple small animal SCI models as well as in naturally occurring SCI in canine patients. In the present study, we have genetically modified canine OECs from the mucosa to constitutively produce enzymatically active ChABC. We have developed a lentiviral vector that can deliver a mammalian modified version of the ChABC gene to mammalian cells, including OECs. Enzyme production was quantified using the Morgan-Elson assay that detects the breakdown products of CSPG digestion in cell supernatants. We confirmed our findings by immunolabelling cell supernatant samples using Western blotting. OECs normal cell function was unaffected by genetic modification as demonstrated by normal microscopic morphology and the presence of the low affinity neurotrophin receptor (p75(NGF)) following viral transduction. We have developed the means to allow production of active ChABC in combination with a promising cell transplant therapy for SCI repair. PMID:27423610

  17. Anatomy, histochemistry, and immunohistochemistry of the olfactory subsystems in mice

    OpenAIRE

    Gonzalo Nuñez; Ignacio Salazar

    2014-01-01

    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...

  18. The Development of Olfactory Organ of Lissotriton Vulgaris (Amphibia, Caudata)

    OpenAIRE

    Kovtun M. F.; Stepanyuk Ya. V.

    2015-01-01

    The Development of Olfactory Organ of Lissotriton vulgaris (Amphibia, Caudata). Kovtun, M. F, Stepanyuk, Ya. V. - Using common histological methods, the morphogenesis of olfactory analyzer peripheral part of Lissotriton vulgaris (Amphibia, Caudata) was studied, during the developmental period starting with olfactory pit laying and finishing with definitive olfactory organ formation. Special attention is paid to vomeronasal organ and vomeronasal gland development. Reasoning from obtained data,...

  19. Olfactory region schwannoma: Excision with preservation of olfaction

    Directory of Open Access Journals (Sweden)

    Pravin Salunke

    2014-01-01

    Full Text Available Olfactory region schwannomas are rare, but when they occur, they commonly arise from the meningeal branches of the trigeminal nerve and may present without involvement of the olfaction. A 24 year old lady presented with hemifacial paraesthesias. Radiology revealed a large olfactory region enhancing lesion. She was operated through a transbasal with olfactory preserving approach. This manuscript highlights the importance of olfactory preservation in such lesions.

  20. Olfactory phenotypic expression unveils human aging

    Science.gov (United States)

    Mazzatenta, Andrea; Cellerino, Alessandro; Origlia, Nicola; Barloscio, Davide; Sartucci, Ferdinando; Giulio, Camillo Di; Domenici, Luciano

    2016-01-01

    The mechanism of the natural aging of olfaction and its declinein the absence of any overt disease conditions remains unclear. Here, we investigated this mechanism through measurement of one of the parameters of olfactory function, the absolute threshold, in a healthy population from childhood to old age. The absolute olfactory threshold data were collected from an Italian observational study with 622 participants aged 5-105 years. A subjective testing procedure of constant stimuli was used, which was also compared to the ‘staircase’ method, with the calculation of the reliability. The n-butanol stimulus was used as an ascending series of nine molar concentrations that were monitored using an electronic nose. The data were analyzed using nonparametric statistics because of the multimodal distribution. We show that the age-related variations in the absolute olfactory threshold are not continuous; instead, there are multiple olfactory phenotypes. Three distinct age-related phenotypes were defined, termed as ‘juvenile’, ‘mature’ and ‘elder’. The frequency of these three phenotypes depends on age. Our data suggest that the sense of smell does not decrease linearly with aging. Our findings provide the basis for further understanding of olfactory loss as an anticipatory sign of aging and neurodegenerative processes. PMID:27027240

  1. Olfactory dysfunction: Correlation of olfactory bulb volume on MRI and objective olfactometry

    International Nuclear Information System (INIS)

    Purpose: To define the role of olfactory bulb volume measurement by magnetic resonance imaging (MRI) for detecting olfactory dysfunction in comparison with objective olfactometry. Materials and Methods: Thirty patients with suspected olfactory dysfunction (16 women, 14 men; mean age 52 years, range 20-79 years) were examined by MRI and objective olfactometry between January 2006 and January 2009. Olfactory bulb volumes were measured by two neuroradiologists using 3D MR data sets. The olfactory function was categorized as normosmia, hyposmia, and anosmia on the basis of objective olfactometry. Pearson correlation coefficients were calculated for objective olfactometry and olfactory bulb volumes on MRI. ROC analysis was performed to determine whether MRI bulb volumes can serve to predict anosmia or hyposmia. Results: The bulb volumes measured by MRI ranged from 0 to 135.9 mm3. Based on olfactometry, anosmia was present in 11 patients (total bulb volume of 15.7 ± 23.3 mm3), hyposmia in 9 patients (total bulb volume of 50.0 ± 25.5 mm3), and normosmia in 10 patients (total bulb volume of 110.7 ± 21.5 mm3). There was good correlation (r>0.9) between objective olfactometry and olfactory bulb volume on MRI. ROC analysis yielded a cut-off value of 32 mm3 for anosmia, which had a sensitivity of 0.91 and specificity of 0.947. The cut-off value for olfactory dysfunction was 80.7 mm3 (sensitivity 0.95; specificity of 0.9). Conclusion: The olfactory bulb volume determined by MRI is a suitable parameter for diagnosing complete or partial loss of the sense of smell. (orig.)

  2. Plastic Fishes

    CERN Multimedia

    Trettnak, Wolfgang

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

  3. Secreted factors from olfactory mucosa cells expanded as free-floating spheres increase neurogenesis in olfactory bulb neurosphere cultures

    Directory of Open Access Journals (Sweden)

    Caldwell Maeve A

    2008-02-01

    Full Text Available Abstract Background The olfactory epithelium is a neurogenic tissue comprising a population of olfactory receptor neurons that are renewed throughout adulthood by a population of stem and progenitor cells. Because of their relative accessibility compared to intra-cranially located neural stem/progenitor cells, olfactory epithelium stem and progenitor cells make attractive candidates for autologous cell-based therapy. However, olfactory stem and progenitor cells expand very slowly when grown as free-floating spheres (olfactory-spheres under growth factor stimulation in a neurosphere assay. Results In order to address whether olfactory mucosa cells extrinsically regulate proliferation and/or differentiation of immature neural cells, we cultured neural progenitor cells derived from mouse neonatal olfactory bulb or subventricular zone (SVZ in the presence of medium conditioned by olfactory mucosa-derived spheres (olfactory-spheres. Our data demonstrated that olfactory mucosa cells produced soluble factors that affect bulbar neural progenitor cell differentiation but not their proliferation when compared to control media. In addition, olfactory mucosa derived soluble factors increased neurogenesis, especially favouring the generation of non-GABAergic neurons. Olfactory mucosa conditioned medium also contained several factors with neurotrophic/neuroprotective properties. Olfactory-sphere conditioned medium did not affect proliferation or differentiation of SVZ-derived neural progenitors. Conclusion These data suggest that the olfactory mucosa does not contain factors that are inhibitory to neural stem/progenitor cell proliferation but does contain factors that steer differentiation toward neuronal phenotypes. Moreover, they suggest that the poor expansion of olfactory-spheres may be in part due to intrinsic properties of the olfactory epithelial stem/progenitor cell population.

  4. Traumatic brain injury and olfactory deficits

    DEFF Research Database (Denmark)

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

    2010-01-01

    PRIMARY OBJECTIVE: Olfactory functions are not systematically evaluated following traumatic brain injury (TBI). This study aimed at comparing two smell tests that are used in a clinical setting. RESEARCH DESIGN: The University of Pennsylvania Smell Identification Test (UPSIT) and the Alberta Smell....... RESULTS: The scores of the two smell tests were significantly correlated. Both tests indicated that patients with frontal lesion performed significantly worse than patients with other types of lesion. Mood and injury severity were not associated with olfactory impairment when age was taken into account...... Alberta Smell test. To refine their diagnosis, the UPSIT can also be used....

  5. The Development of Olfactory Organ of Lissotriton Vulgaris (Amphibia, Caudata

    Directory of Open Access Journals (Sweden)

    Kovtun M. F.

    2015-12-01

    Full Text Available The Development of Olfactory Organ of Lissotriton vulgaris (Amphibia, Caudata. Kovtun, M. F, Stepanyuk, Ya. V. - Using common histological methods, the morphogenesis of olfactory analyzer peripheral part of Lissotriton vulgaris (Amphibia, Caudata was studied, during the developmental period starting with olfactory pit laying and finishing with definitive olfactory organ formation. Special attention is paid to vomeronasal organ and vomeronasal gland development. Reasoning from obtained data, we consider that vomeronasal organ emerged as the result of olfactory epithelium and nasal cavity differentiation.

  6. Olfactory lateralization in homing pigeons: initial orientation of birds receiving a unilateral olfactory input.

    Science.gov (United States)

    Gagliardo, Anna; Pecchia, Tommaso; Savini, Maria; Odetti, Francesca; Ioalè, Paolo; Vallortigara, Giorgio

    2007-03-01

    It has been shown that homing pigeons (Columba livia) rely on olfactory cues to navigate from unfamiliar locations. In fact, the integrity of the olfactory system, from the olfactory mucosa to the piriform cortex, is required for pigeons to navigate over unfamiliar areas. Recently it has been shown that there is a functional asymmetry in the piriform cortex, with the left piriform cortex more involved in the use of the olfactory navigational map than the right piriform cortex. To investigate further the lateralization of the olfactory system in relation to navigational processes in carrier pigeons, we compared their homing performance after either their left or the right nostril was plugged. Contrary to our expectations, we observed an impairment in the initial orientation of the pigeons with their right nostril plugged. However, both groups released with one nostril plugged tended to be poorer than control pigeons in their homing performance. The observed asymmetry in favour of the right nostril might be due to projections from the olfactory bulbs to the contralateral globus pallidum, a structure involved in motor responses. PMID:17425577

  7. Olfactory processing: detection of rapid changes.

    Science.gov (United States)

    Croy, Ilona; Krone, Franziska; Walker, Susannah; Hummel, Thomas

    2015-06-01

    Changes in the olfactory environment have a rather poor chance of being detected. Aim of the present study was to determine, whether the same (cued) or different (uncued) odors can generally be detected at short inter stimulus intervals (ISI) below 2.5 s. Furthermore we investigated, whether inhibition of return, an attentional phenomenon facilitating the detection of new stimuli at longer ISI, is present in the domain of olfaction. Thirteen normosmic people (3 men, 10 women; age range 19-27 years; mean age 23 years) participated. Stimulation was performed using air-dilution olfactometry with 2 odors: phenylethylalcohol and hydrogen disulfide. Reaction time to target stimuli was assessed in cued and uncued conditions at ISIs of 1, 1.5, 2, and 2.5 s. There was a significant main effect of ISI, indicating that odors presented only 1 s apart are missed frequently. Uncued presentation facilitated detection at short ISIs, implying that changes of the olfactory environment are detected better than presentation of the same odor again. Effects in relation to "olfactory inhibition of return," on the other hand, are not supported by our results. This suggests that attention works different for the olfactory system compared with the visual and auditory systems. PMID:25911421

  8. Nanobiosensors based on individual olfactory receptors

    CERN Document Server

    Pajot-Augy, E

    2008-01-01

    In the SPOT-NOSED European project, nanoscale sensing elements bearing olfactory receptors and grafted onto functionalized gold substrates are used as odorant detectors to develop a new concept of nanobioelectronic nose, through sensitive impedancemetric measurement of single receptor conformational change upon ligand binding, with a better specificity and lower detection threshold than traditional physical sensors.

  9. 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.

  10. Dopaminergic modulation of synaptic transmission and neuronal activity patterns in the zebrafish homolog of olfactory cortex

    Directory of Open Access Journals (Sweden)

    Rainer W. Friedrich

    2012-10-01

    Full Text Available Dopamine (DA is an important modulator of synaptic transmission and plasticity that is causally involved in fundamental brain functions and dysfunctions. We examined the dopaminergic modulation of synaptic transmission and sensory responses in telencephalic area Dp of zebrafish, the homologue of olfactory cortex. By combining anatomical tracing and immunohistochemistry, we detected no DA neurons in Dp itself but long-range dopaminergic input from multiple other brain areas. Whole-cell recordings revealed no obvious effects of DA on membrane potential or input resistance in the majority of Dp neurons. Electrical stimulation of the olfactory tracts produced a complex sequence of synaptic currents in Dp neurons. DA selectively decreased inhibitory currents with little or no effect on excitatory components. Multiphoton calcium imaging showed that population responses of Dp neurons to olfactory tract stimulation or odor application were enhanced by DA, consistent with its effect on inhibitory synaptic transmission. These effects of DA were blocked by an antagonist of D2-like receptors. DA therefore disinhibits and reorganizes sensory responses in Dp. This modulation may affect sensory perception and could be involved in the experience-dependent modification of odor representations.

  11. The functional significance of newly born neurons integrated into olfactory bulb circuits

    Directory of Open Access Journals (Sweden)

    Masayuki eSakamoto

    2014-05-01

    Full Text Available The olfactory bulb (OB is the first central processing center for olfactory information connecting with higher areas in the brain, and this neuronal circuitry mediates a variety of odor-evoked behavioral responses. In the adult mammalian brain, continuous neurogenesis occurs in two restricted regions, the subventricular zone (SVZ of the lateral ventricle and the hippocampal dentate gyrus. New neurons born in the SVZ migrate through the rostral migratory stream and are integrated into the neuronal circuits of the OB throughout life. The significance of this continuous supply of new neurons in the OB has been implicated in plasticity and memory regulation. Two decades of huge investigation in adult neurogenesis revealed the biological importance of integration of new neurons into the olfactory circuits. In this review, we highlight the recent findings about the physiological functions of newly generated neurons in rodent OB circuits and then discuss the contribution of neurogenesis in the brain function. Finally, we introduce cutting edge technologies to monitor and manipulate the activity of new neurons.

  12. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  13. Cosmetic Plastic Surgery Statistics

    Science.gov (United States)

    2014 Cosmetic Plastic Surgery Statistics Cosmetic Procedure Trends 2014 Plastic Surgery Statistics Report Please credit the AMERICAN SOCIETY OF PLASTIC SURGEONS when citing statistical data or using ...

  14. Plastic fish

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  15. Sex hormone binding globulin in the rat olfactory system.

    Science.gov (United States)

    Ploss, V; Gebhart, V M; Dölz, W; Jirikowski, G F

    2014-05-01

    Ovarian steroids are known to act on the olfactory system. Their mode of action, however, is mostly unclear to date since nuclear receptors are lacking in sensory neurons. Here we used immunocytochemistry and RT-PCR to study expression and distribution of sex hormone binding globulin (SHBG) in the rat olfactory system. Single sensory cells in the olfactory mucosa and their projections in the olfactory bulb showed specific SHBG immunostaining as determined by double immunofluorescence with olfactory marker protein OMP. Larger groups of SHBG stained sensory cells occurred in the vomeronasal organ (VNO). A portion of the olfactory glomeruli in the accessory olfactory bulb showed large networks of SHBG positive nerve fibres. Some of the mitral cells showed SHBG immune fluorescence. RT-PCR revealed SHBG encoding mRNA in the olfactory mucosa, in the VNO and in the olfactory bulbs indicating intrinsic expression of the binding globulin. The VNO and its related projections within the limbic system are known to be sensitive to gonadal steroid hormones. We conclude that SHBG may be of functional importance for rapid effects of olfactory steroids on limbic functions including the control of reproductive behaviours through pheromones. PMID:24681170

  16. 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 ...

  17. File list: Unc.Oth.50.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Oth.50.AllAg.Olfactory_epithelium mm9 Unclassified Others Olfactory epithelium ...SRX112960 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.50.AllAg.Olfactory_epithelium.bed ...

  18. 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 ...

  19. 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 ...

  20. Plastic bronchitis

    Directory of Open Access Journals (Sweden)

    Anil Kumar Singhi

    2015-01-01

    Full Text Available Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its current understanding.

  1. Plastic bronchitis

    OpenAIRE

    Anil Kumar Singhi; Bharathi Vinoth; Sarah Kuruvilla; Kothandam Sivakumar

    2015-01-01

    Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its curre...

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

    OpenAIRE

    Fomina Alla F; Dadsetan Sepehr; Chen Huaiyang; Gong Qizhi

    2008-01-01

    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...

  3. Olfactory schwannoma: A report of two cases and literature review

    OpenAIRE

    Zheng Wang; , Wei Zhang; Gan You; Jiangfei Wang; Guilin Li; Zhixian Gao; Jian Xie

    2014-01-01

    Intracranial schwannoma is a kind of benign intracranial tumors, derived from neuron myelin sheath, growing slowly and curable. Olfactory schwannoma is an exceedingly rare kind of schwannoma, whose origin is still uncovered. Although several theories have been put up for pathogenesis of olfactory schwannoma, till now, none of these hypotheses has been widely accepted and acknowledged officially. Up to date, only 46 cases of olfactory schwannoma were reported across numerous institutes worldwi...

  4. 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...

  5. Organization and expression of canine olfactory receptor genes.

    OpenAIRE

    Issel-Tarver, L; Rine, J

    1996-01-01

    Four members of the canine olfactory receptor gene family were characterized. The predicted proteins shared 40-64% identity with previously identified olfactory receptors. The four subfamilies identified in Southern hybridization experiments had as few as 2 and as many as 20 members. All four genes were expressed exclusively in olfactory epithelium. Expression of multiple members of the larger subfamilies was detected, suggesting that most if not all of the cross-hybridizing bands in genomic ...

  6. Olfactory Decoding Method Using Neural Spike Signals

    Institute of Scientific and Technical Information of China (English)

    Kyung-jin YOU; Hyun-chool SHIN

    2010-01-01

    This paper presents a travel method for inferring the odor based on naval activities observed from rats'main olfactory bulbs.Mufti-channel extmcellular single unit recordings are done by microwire electrodes(Tungsten,50μm,32 channels)innplanted in the mitral/tufted cell layers of the main olfactory bulb of the anesthetized rats to obtain neural responses to various odors.Neural responses as a key feature are measured by subtraction firing rates before stimulus from after.For odor irderenoe,a decoding method is developed based on the ML estimation.The results show that the average decoding acauacy is about 100.0%,96.0%,and 80.0% with three rats,respectively.This wait has profound implications for a novel brain-madune interface system far odor inference.

  7. Neurogenesis in the adult olfactory bulb

    Institute of Scientific and Technical Information of China (English)

    Angela Pignatelli; Cristina Gambardella; Ottorino Belluzzi

    2011-01-01

    Neurogenesis is the process by which cells divide, migrate, and subsequently differentiate into a neuronal phenotype. Significant rates of neurogenesis persist into adulthood in two brain regions, the subgranular zone of the dentate gyrus and the subventricular zone of the lateral ventricles. Cells of the subventricular zone divide and migrate via the rostral migratory stream to the olfactory bulb where they differentiate into granule and periglomerular cells. With the discovery of large-scale neurogenesis in the adult brain, there have been significant efforts to identify the mechanisms that control this process as well as the role of these cells in neuronal functioning. Although many questions remain unanswered, new insights appear daily about adult neurogenesis, regulatory mechanisms, and the fates of the progeny. In this review we highlight the main studies investigating factors that regulate neurogenesis in the subventricular zone, neuronal migration to the olfactory bulb, neuronal integration into the existing bulbar network and shortly discuss the functional meaning of this process.

  8. Olfactory Orientation and Navigation in Humans.

    Science.gov (United States)

    Jacobs, Lucia F; Arter, Jennifer; Cook, Amy; Sulloway, Frank J

    2015-01-01

    Although predicted by theory, there is no direct evidence that an animal can define an arbitrary location in space as a coordinate location on an odor grid. Here we show that humans can do so. Using a spatial match-to-sample procedure, humans were led to a random location within a room diffused with two odors. After brief sampling and spatial disorientation, they had to return to this location. Over three conditions, participants had access to different sensory stimuli: olfactory only, visual only, and a final control condition with no olfactory, visual, or auditory stimuli. Humans located the target with higher accuracy in the olfaction-only condition than in the control condition and showed higher accuracy than chance. Thus a mechanism long proposed for the homing pigeon, the ability to define a location on a map constructed from chemical stimuli, may also be a navigational mechanism used by humans. PMID:26083337

  9. Olfactory Orientation and Navigation in Humans.

    Directory of Open Access Journals (Sweden)

    Lucia F Jacobs

    Full Text Available Although predicted by theory, there is no direct evidence that an animal can define an arbitrary location in space as a coordinate location on an odor grid. Here we show that humans can do so. Using a spatial match-to-sample procedure, humans were led to a random location within a room diffused with two odors. After brief sampling and spatial disorientation, they had to return to this location. Over three conditions, participants had access to different sensory stimuli: olfactory only, visual only, and a final control condition with no olfactory, visual, or auditory stimuli. Humans located the target with higher accuracy in the olfaction-only condition than in the control condition and showed higher accuracy than chance. Thus a mechanism long proposed for the homing pigeon, the ability to define a location on a map constructed from chemical stimuli, may also be a navigational mechanism used by humans.

  10. Olfactory identification ability in anorexia nervosa.

    OpenAIRE

    Kopala, L C; Good, K; Goldner, E M; Birmingham, C L

    1995-01-01

    OBJECTIVE: The hypothesis tested was that patients with severe eating disorders would demonstrate olfactory identification deficits as a result of zinc deficiency or malnutrition. METHOD: The University of Pennsylvania Smell Identification Test (UPSIT) was administered to 27 hospitalized female patients with anorexia nervosa and 50 normal control female subjects. For a subgroup of patients, serum zinc levels and body mass indices were obtained at pre- and post-nutritional repletion phases. RE...

  11. Modeling the Olfactory Bulb - Coupled Nonlinear Oscillators

    OpenAIRE

    Li, Zhaoping; Hopfield, J J

    1989-01-01

    The olfactory bulb of mammals aids in the discrimination of odors. A mathematical model based on the bulbar anatomy and electrophysiology is described. Simulations produce a 35-60 Hz modulated activity coherent across the bulb, mimicing the observed field potentials. The decision states (for the odor information) here can be thought of as stable cycles, rather than point stable states typical of simpler neuro-computing models. Analysis and simulations show that a group of...

  12. Olfactory assessment using the NIH Toolbox

    OpenAIRE

    Dalton, Pamela; Doty, Richard L.; Murphy, Claire; Frank, Robert; Hoffman, Howard J.; Maute, Christopher; Kallen, Michael A.; Slotkin, Jerry

    2013-01-01

    The human olfactory system provides us with information about our environment that is critical to our physical and psychological well-being. Individuals can vary widely in their ability to detect, recognize, and identify odors, but still be within the range of normal function. Although several standardized tests of odor identification are available, few specifically address the issues in testing very young children, most of whom are likely to be unfamiliar with many of the odor stimuli used i...

  13. Olfactory Orientation and Navigation in Humans

    OpenAIRE

    Jacobs, Lucia F.; Arter, Jennifer; Cook, Amy; Sulloway, Frank J.

    2015-01-01

    Although predicted by theory, there is no direct evidence that an animal can define an arbitrary location in space as a coordinate location on an odor grid. Here we show that humans can do so. Using a spatial match-to-sample procedure, humans were led to a random location within a room diffused with two odors. After brief sampling and spatial disorientation, they had to return to this location. Over three conditions, participants had access to different sensory stimuli: olfactory only, visual...

  14. Electrophysiological Measurements from a Moth Olfactory System

    OpenAIRE

    Syed, Zainulabeuddin; Leal, Walter S.

    2011-01-01

    Insect olfactory systems provide unique opportunities for recording odorant-induced responses in the forms of electroantennograms (EAG) and single sensillum recordings (SSR), which are summed responses from all odorant receptor neurons (ORNs) located on the antenna and from those housed in individual sensilla, respectively. These approaches have been exploited for getting a better understanding of insect chemical communication. The identified stimuli can then be used as either attractants or ...

  15. 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.

  16. 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.

  17. Anatomy, histochemistry, and immunohistochemistry of the olfactory subsystems in mice.

    Science.gov (United States)

    Barrios, Arthur W; Núñez, Gonzalo; Sánchez Quinteiro, Pablo; Salazar, Ignacio

    2014-01-01

    The four regions of the murine nasal cavity featuring olfactory neurons were studied anatomically and by labeling 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 labeled by Lycopersicum esculentum agglutinin, while Ulex europaeus agglutinin I labels all and only tissues expressing Gαi2 (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. PMID:25071468

  18. 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. PMID:25225297

  19. Application of the European Test of Olfactory Capabilities in patients with olfactory impairment.

    Science.gov (United States)

    Joussain, P; Bessy, M; Faure, F; Bellil, D; Landis, B N; Hugentobler, M; Tuorila, H; Mustonen, S; Vento, S I; Delphin-Combe, F; Krolak-Salmon, P; Rouby, C; Bensafi, M

    2016-02-01

    A central issue in olfaction concerns the characterization of loss of olfactory function: partial (hyposmia) or total (anosmia). This paper reports the application in a clinical setting of the European Test of Olfactory Capabilities (ETOC), combining odor detection and identification. The study included three phases. In phase 1, anosmics, hyposmics and controls were tested with the 16-items version of the ETOC. In phase 2, a short version of the ETOC was developed: patients with and controls without olfactory impairment were tested on a 6-items ETOC. In phase 3, to predict olfactory impairments in new individuals, the 16-items ETOC was administered on samples of young and older adults, and the 6-items version was applied in samples of young, elderly participants and Alzheimer patients. In phase 1, linear discriminant analysis (LDA) of ETOC scores classified patients and controls with 87.5 % accuracy. In phase 2, LDA provided 84 % correct classification. Results of phase 3 revealed: (1) 16-items ETOC: whereas in young adults, 10 % were classified as hyposmic and 90 % as normosmic, in elderly, 1 % were classified as anosmic, 39 % hyposmic and 60 % normosmic; (2) 6-items ETOC: 15 % of the young adults were classified as having olfactory impairment, compared to 28 % in the older group and 83 % in Alzheimer patients. In conclusion, the ETOC enables characterizing the prevalence of olfactory impairment in young subjects and in normal and pathological aging. Whereas the 16-items ETOC is more discriminant, the short ETOC may provide a fast (5-10 min) tool to assess olfaction in clinical settings. PMID:25711735

  20. Neuropeptide S Facilitates Mice Olfactory Function through Activation of Cognate Receptor-Expressing Neurons in the Olfactory Cortex

    OpenAIRE

    Shao, Yu-Feng; Zhao, Peng; Dong, Chao-Yu; Li, Jing; Kong, Xiang-pan; Wang, Hai-Liang; Dai, Li-Rong; Hou, Yi-Ping

    2013-01-01

    Neuropeptide S (NPS) is a newly identified neuromodulator located in the brainstem and regulates various biological functions by selectively activating the NPS receptors (NPSR). High level expression of NPSR mRNA in the olfactory cortex suggests that NPS-NPSR system might be involved in the regulation of olfactory function. The present study was undertaken to investigate the effects of intracerebroventricular (i.c.v.) injection of NPS or co-injection of NPSR antagonist on the olfactory behavi...

  1. Self-Ratings of Olfactory Function Reflect Odor Annoyance Rather than Olfactory Acuity

    DEFF Research Database (Denmark)

    Knaapila, Antti; Tuorila, Hely; Kyvik, Kirsten;

    2008-01-01

    OBJECTIVE/HYPOTHESIS:: Self-ratings of olfactory function correlates often poorly with results of objective smell tests. We explored them relative to self-rating of odor annoyance, to odor identification ability, and to mean perceived intensity of odors, and estimated relative genetic and...... Kingdom rated their sense of smell and annoyance caused by ambient smells (e.g., smells of foods) using seven categories, and performed odor identification and evaluation task for six scratch-and-sniff odor stimuli. RESULTS:: The self-rating of olfactory function correlated with the self-rating of odor...

  2. Morphometry of olfactory lamellae and olfactory receptor neurons during the life history of chum salmon (Oncorhynchus keta).

    Science.gov (United States)

    Kudo, Hideaki; Shinto, Masakazu; Sakurai, Yasunori; Kaeriyama, Masahide

    2009-09-01

    It is generally accepted that anadromous Pacific salmon (genus Oncorhynchus) imprint to odorants in their natal streams during their seaward migration and use olfaction to identify these during their homeward migration. Despite the importance of the olfactory organ during olfactory imprinting, the development of this structure is not well understood in Pacific salmon. Olfactory cues from the environment are relayed to the brain by the olfactory receptor neurons (ORNs) in the olfactory organ. Thus, we analyzed morphometric changes in olfactory lamellae of the peripheral olfactory organ and in the quantity of ORNs during life history from alevin to mature in chum salmon (Oncorhynchus keta). The number of lamellae increased markedly during early development, reached 18 lamellae per unilateral peripheral olfactory organ in young salmon with a 200 mm in body size, and maintained this lamellar complement after young period. The number of ORNs per olfactory organ was about 180,000 and 14.2 million cells in fry and mature salmon, respectively. The relationship between the body size (fork length) and number of ORNs therefore revealed an allometric association. Our results represent the first quantitative analysis of the number of ORNs in Pacific salmon and suggest that the number of ORNs is synchronized with the fork length throughout its life history. PMID:19587025

  3. Metacognitive knowledge of olfactory dysfunction in Parkinson's disease.

    Science.gov (United States)

    White, Theresa L; Sadikot, Abbas F; Djordjevic, Jelena

    2016-04-01

    It is well known that patients with Parkinson's Disease (PD) suffer from olfactory impairments, but it is not clear whether patients are aware of their level of deficit in olfactory functioning. Since PD is a neurodegenerative disorder and its progression may be correlated with olfactory loss (Ansari & Johnson, 1975; but see also Doty, Deems, & Stellar, 1988), it is possible that these patients would be subject to metacognitive errors of over-estimation of olfactory ability (White & Kurtz, 2003). Nineteen non-demented PD patients and 19 age-matched controls were each given an objective measure of olfactory identification (the UPSIT, Doty, Shaman, Kimmelman, & Dann, 1984) and a subjective measure involving a questionnaire that asked them to self-rate both their olfactory function generally and their ability to smell each of 20 odors, 12 of which were assessed on the UPSIT. All of the PD patients showed impaired olfactory ability, as did 7 of the controls, according to the UPSIT norms. Self-rated and performance-based olfactory ability scores were significantly correlated in controls (r=.49, p=.03) but not in patients with PD (r=.20, p=.39). When the 12 odors common to both the self-rated questionnaire and UPSIT were compared, PD patients were less accurate than controls (t(36)=-4.96, pmetacognitive awareness of their ability than controls. These results support the idea that olfactory metacognition is often impaired in PD, as well as in controls recruited for normosmic ability (Wehling, Nordin, Espeseth, Reinvang, & Lundervold, 2011), and indicate that people with PD generally exhibit over-estimation of their olfactory ability at a rate that is higher than controls. These findings imply that PD patients, unaware of their olfactory deficit, are at greater risk of harm normally detected through olfaction, such as smoke or spoiled foods. PMID:26867087

  4. Neuropeptide S facilitates mice olfactory function through activation of cognate receptor-expressing neurons in the olfactory cortex.

    Directory of Open Access Journals (Sweden)

    Yu-Feng Shao

    Full Text Available Neuropeptide S (NPS is a newly identified neuromodulator located in the brainstem and regulates various biological functions by selectively activating the NPS receptors (NPSR. High level expression of NPSR mRNA in the olfactory cortex suggests that NPS-NPSR system might be involved in the regulation of olfactory function. The present study was undertaken to investigate the effects of intracerebroventricular (i.c.v. injection of NPS or co-injection of NPSR antagonist on the olfactory behaviors, food intake, and c-Fos expression in olfactory cortex in mice. In addition, dual-immunofluorescence was employed to identify NPS-induced Fos immunereactive (-ir neurons that also bear NPSR. NPS (0.1-1 nmol i.c.v. injection significantly reduced the latency to find the buried food, and increased olfactory differentiation of different odors and the total sniffing time spent in olfactory habituation/dishabituation tasks. NPS facilitated olfactory ability most at the dose of 0.5 nmol, which could be blocked by co-injection of 40 nmol NPSR antagonist [D-Val(5]NPS. NPS administration dose-dependently inhibited food intake in fasted mice. Ex-vivo c-Fos and NPSR immunohistochemistry in the olfactory cortex revealed that, as compared with vehicle-treated mice, NPS markedly enhanced c-Fos expression in the anterior olfactory nucleus (AON, piriform cortex (Pir, ventral tenia tecta (VTT, the anterior cortical amygdaloid nucleus (ACo and lateral entorhinal cortex (LEnt. The percentage of Fos-ir neurons that also express NPSR were 88.5% and 98.1% in the AON and Pir, respectively. The present findings demonstrated that NPS, via selective activation of the neurons bearing NPSR in the olfactory cortex, facilitates olfactory function in mice.

  5. 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. PMID:21270307

  6. The mitosis and immunocytochemistry of olfactory ensheathing cells from nasal olfactory mucosa

    Institute of Scientific and Technical Information of China (English)

    LIU Jin-bo; TANG Tian-si; GONG Ai-hua; SHENG Wei-hua; YANG Ji-cheng

    2005-01-01

    Objective: To culture olfactory ensheathing cells (OECs) of rats in vitro and to investigate its morphology, mitosis and immunocytochemistry, and to explore if the OECs could be a new donation for transplantation. Methods: OECs were harvested from olfactory mucosa of Sprague Dawleys rats based on the differing rates of attachment of the various cell types, followed by glial fibrillary acidic protein (GFAP), nerve growth factor (NGF), anti-low affinity receptor for NGF (NGFRp75), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and S-100 immunocytochemistry. The morphological changes and mitosis were observed under a phase contrast microscope at different culture time.Results: Three morphologically distinct types of cells, bipolar,multipolar and flat morphology were present in the primary culture of adult rat olfactory mucosa. Mitosis was characterized by a retraction of all processes, forming a sphere that divided into spherical daughter cells, the daughter cells sent out their processes. The OECs were immunoreactive for GFAP, NGFRp75, S-100, NGF, BDNF and NT-3. Conclusions: The OECs from nasal olfactory mucosa cultivated in the medium with fetal bovine serum could survive, divide, differentiate, and express the neurotrophin. It may become an accessible source for autologous grafting in spinal cord injury.

  7. 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…

  8. The olfactory circuit of the fruit fly Drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The olfactory circuit of the fruit fly Drosophila melanogaster has emerged in recent years as an excellent paradigm for studying the principles and mechanisms of information processing in neuronal circuits. We discuss here the organizational principles of the olfactory circuit that make it an attractive model for experimental manipulations, the lessons that have been learned, and future challenges.

  9. Neural circuits mediating olfactory-driven behavior in fish

    Directory of Open Access Journals (Sweden)

    Florence Kermen

    2013-04-01

    Full Text Available The fish olfactory system processes odor signals and mediates behaviors that are crucial for survival such as foraging, courtship and alarm response. Although the upstream olfactory brain areas (olfactory epithelium and olfactory bulb are well studied, less is known about their target brain areas and the role they play in generating odor-driven behaviors. Here we review a broad range of literature on the anatomy, physiology and behavioral output of the olfactory system and its target areas in a wide range of teleost fish. Additionally, we discuss how applying recent technological advancements to the zebrafish (Danio rerio could help in understanding the function of these target areas. We hope to provide a framework for elucidating the neural circuit computations underlying the odor-driven behaviors in this small, transparent and genetically amenable vertebrate.

  10. Human Neural Cells Transiently Express Reelin during Olfactory Placode Development

    Science.gov (United States)

    Antal, M. Cristina; Samama, Brigitte; Ghandour, M. Said; Boehm, Nelly

    2015-01-01

    Reelin, an extracellular glycoprotein is essential for migration and correct positioning of neurons during development. Since the olfactory system is known as a source of various migrating neuronal cells, we studied Reelin expression in the two chemosensory olfactory systems, main and accessory, during early developmental stages of human foetuses/embryos from Carnegie Stage (CS) 15 to gestational week (GW) 14. From CS 15 to CS 18, but not at later stages, a transient expression of Reelin was detected first in the presumptive olfactory and then in the presumptive vomeronasal epithelium. During the same period, Reelin-positive cells detach from the olfactory/vomeronasal epithelium and migrate through the mesenchyme beneath the telencephalon. Dab 1, an adaptor protein of the Reelin pathway, was simultaneously expressed in the migratory mass from CS16 to CS17 and, at later stages, in the presumptive olfactory ensheathing cells. Possible involvements of Reelin and Dab 1 in the peripheral migrating stream are discussed. PMID:26270645

  11. Histochemical study of the olfactory mucosae of the horse.

    Science.gov (United States)

    Lee, Kwang-Hyup; Park, Changnam; Bang, Hyojin; Ahn, Meejung; Moon, Changjong; Kim, Seungjoon; Shin, Taekyun

    2016-05-01

    The olfactory mucosae of the horse were examined by using histology and lectin histochemistry to characterize the carbohydrate sugar residues therein. Histological findings revealed that olfactory epithelium (OE) consisted of both olfactory marker protein (OMP)- and protein gene product (PGP) 9.5-positive receptor cells, supporting cells and basal cells with intervening secretory ducts from Bowman's glands. Mucus histochemistry showed that Bowman's gland acini contain periodic acid-Schiff (PAS) reagent-positive neutral mucins and alcian blue pH 2.5-positive mucosubstances. Lectin histochemistry revealed that a variety of carbohydrate sugar residues, including N-acetylglucosamine, mannose, galactose, N-acetylgalactosamine, fucose and complex type N-glycan groups, are present in the various cell types in the olfactory mucosa at varying levels. Collectively, this is the first descriptive study of horse olfactory mucosa to characterize carbohydrate sugar residues in the OE and Bowman's glands. PMID:27040092

  12. An olfactory demography of a diverse metropolitan population

    Directory of Open Access Journals (Sweden)

    Keller Andreas

    2012-10-01

    Full Text Available Abstract Background Human perception of the odour environment is highly variable. People vary both in their general olfactory acuity as well as in if and how they perceive specific odours. In recent years, it has been shown that genetic differences contribute to variability in both general olfactory acuity and the perception of specific odours. Odour perception also depends on other factors such as age and gender. Here we investigate the influence of these factors on both general olfactory acuity and on the perception of 66 structurally and perceptually different odours in a diverse subject population. Results We carried out a large human olfactory psychophysics study of 391 adult subjects in metropolitan New York City, an ethnically and culturally diverse North American metropolis. 210 of the subjects were women and the median age was 34.6 years (range 19–75. We recorded ~2,300 data points per subject to obtain a comprehensive perceptual phenotype, comprising multiple perceptual measures of 66 diverse odours. We show that general olfactory acuity correlates with gender, age, race, smoking habits, and body type. Young, female, non-smoking subjects had the highest average olfactory acuity. Deviations from normal body type in either direction were associated with decreased olfactory acuity. Beyond these factors we also show that, surprisingly, there are many odour-specific influences of race, age, and gender on olfactory perception. We show over 100 instances in which the intensity or pleasantness perception of an odour is significantly different between two demographic groups. Conclusions These data provide a comprehensive snapshot of the olfactory sense of a diverse population. Olfactory acuity in the population is most strongly influenced by age, followed by gender. We also show a large number of diverse correlations between demographic factors and the perception of individual odours that may reflect genetic differences as well as different

  13. Nasal toxicity, carcinogenicity, and olfactory uptake of metals.

    Science.gov (United States)

    Sunderman, F W

    2001-01-01

    Occupational exposures to inhalation of certain metal dusts or aerosols can cause loss of olfactory acuity, atrophy of the nasal mucosa, mucosal ulcers, perforated nasal septum, or sinonasal cancer. Anosmia and hyposmia have been observed in workers exposed to Ni- or Cd-containing dusts in alkaline battery factories, nickel refineries, and cadmium industries. Ulcers of the nasal mucosa and perforated nasal septum have been reported in workers exposed to Cr(VI) in chromate production and chrome plating, or to As(III) in arsenic smelters. Atrophy of the olfactory epithelium has been observed in rodents following inhalation of NiSO4 or alphaNi3S2. Cancers of the nose and nasal sinuses have been reported in workers exposed to Ni compounds in nickel refining, cutlery factories, and alkaline battery manufacture, or to Cr(VI) in chromate production and chrome plating. In animals, several metals (eg, Al, Cd, Co, Hg, Mn, Ni, Zn) have been shown to pass via olfactory receptor neurons from the nasal lumen through the cribriform plate to the olfactory bulb. Some metals (eg, Mn, Ni, Zn) can cross synapses in the olfactory bulb and migrate via secondary olfactory neurons to distant nuclei of the brain. After nasal instillation of a metal-containing solution, transport of the metal via olfactory axons can occur rapidly, within hours or a few days (eg, Mn), or slowly over days or weeks (eg, Ni). The olfactory bulb tends to accumulate certain metals (eg, Al, Bi, Cu, Mn, Zn) with greater avidity than other regions of the brain. The molecular mechanisms responsible for metal translocation in olfactory neurons and deposition in the olfactory bulb are unclear, but complexation by metal-binding molecules such as carnosine (beta-alanyl-L-histidine) may be involved. PMID:11314863

  14. Overcoming maladaptive plasticity through plastic compensation

    Institute of Scientific and Technical Information of China (English)

    Matthew R.J.MORRIS; Sean M.ROGERS

    2013-01-01

    Most species evolve within fluctuating environments,and have developed adaptations to meet the challenges posed by environmental heterogeneity.One such adaptation is phenotypic plasticity,or the ability of a single genotype to produce multiple environmentally-induced phenotypes.Yet,not all plasticity is adaptive.Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution,much less is known about maladaptive plasticity.However,maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments.This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity,two of which involve genetic changes (standing genetic variation,genetic compensation) and two of which do not (standing epigenetic variation,plastic compensation).Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity.In particular,plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence.We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

  15. Olfactory Delusional Syndrome and Intracranial Meningioma

    Directory of Open Access Journals (Sweden)

    Michele Rotondo

    2011-01-01

    Full Text Available We report the case of a 37-year-old female in which the removal of a suprasellar neoplasm was accompanied by the disappearance of a longstanding olfactory delusion syndrome. In primary care the patient condition was exclusively thought to be psychic in origin, neglecting the possible, not infrequent, organic contribution. The delayed diagnosis produced neurological impairment, only partially recovered after surgical therapy. This case might help to improve the patient management via multi-specialist cooperation and to broaden the knowledge about somatic mechanisms of psychic disturbances, are not often taken into account.

  16. Overcoming maladaptive plasticity through plastic compensation

    OpenAIRE

    Matthew R.J. MORRIS, Sean M. ROGERS

    2013-01-01

    Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plastici...

  17. The functional upregulation of piriform cortex is associated with cross-modal plasticity in loss of whisker tactile inputs.

    Directory of Open Access Journals (Sweden)

    Bing Ye

    Full Text Available BACKGROUND: Cross-modal plasticity is characterized as the hypersensitivity of remaining modalities after a sensory function is lost in rodents, which ensures their awareness to environmental changes. Cellular and molecular mechanisms underlying cross-modal sensory plasticity remain unclear. We aim to study the role of different types of neurons in cross-modal plasticity. METHODOLOGY/PRINCIPAL FINDINGS: In addition to behavioral tasks in mice, whole-cell recordings at the excitatory and inhibitory neurons, and their two-photon imaging, were conducted in piriform cortex. We produced a mouse model of cross-modal sensory plasticity that olfactory function was upregulated by trimming whiskers to deprive their sensory inputs. In the meantime of olfactory hypersensitivity, pyramidal neurons and excitatory synapses were functionally upregulated, as well as GABAergic cells and inhibitory synapses were downregulated in piriform cortex from the mice of cross-modal sensory plasticity, compared with controls. A crosswire connection between barrel cortex and piriform cortex was established in cross-modal plasticity. CONCLUSION/SIGNIFICANCE: An upregulation of pyramidal neurons and a downregulation of GABAergic neurons strengthen the activities of neuronal networks in piriform cortex, which may be responsible for olfactory hypersensitivity after a loss of whisker tactile input. This finding provides the clues for developing therapeutic strategies to promote sensory recovery and substitution.

  18. Patterns of olfactory bulb neurogenesis in the adult zebrafish are altered following reversible deafferentation.

    Science.gov (United States)

    Trimpe, Darcy M; Byrd-Jacobs, Christine A

    2016-09-01

    Adult brain plasticity can be investigated using reversible methods that remove afferent innervation but allow return of sensory input. Repeated intranasal irrigation with Triton X-100 in adult zebrafish diminishes innervation to the olfactory bulb, resulting in a number of alterations in bulb structure and function, and cessation of the treatment allows for reinnervation and recovery. Using bromodeoxyuridine, Hu, and caspase-3 immunoreactivity we examined cell proliferation, differentiation, migration, and survival under conditions of acute and chronic deafferentation and reafferentation. Cell proliferation within the olfactory bulb was not influenced by acute or chronic deafferentation or reafferentation, but cell fate (including differentiation, migration, and/or survival of newly formed cells) was affected. We found that chronic deafferentation caused a bilateral increase in the number of newly formed cells that migrated into the bulb, although the amount of cell death of these new cells was significantly increased compared to untreated fish. Reafferentation also increased the number of newly formed cells migrating into both bulbs, suggesting that the deafferentation effect on cell fate was maintained. Reafferentation resulted in a decrease in newly formed cells that became neurons and, although death of newly formed cells was not altered from control levels, survival was reduced in relation to that seen in chronically deafferented fish. The potential effect of age on cell genesis was also examined. While the amount of cell migration into the olfactory bulbs was not affected by fish age, more of the newly formed cells became neurons in older fish. Younger fish displayed more cell death under conditions of chronic deafferentation. In sum, our results show that reversible deafferentation affects several aspects of cell fate, including cell differentiation, migration, and survival, and age of the fish influences the response to deafferentation. PMID:27343831

  19. Neural correlates of behavioural olfactory sensitivity changes seasonally in European starlings.

    Directory of Open Access Journals (Sweden)

    Geert De Groof

    Full Text Available BACKGROUND: Possibly due to the small size of the olfactory bulb (OB as compared to rodents, it was generally believed that songbirds lack a well-developed sense of smell. This belief was recently revised by several studies showing that various bird species, including passerines, use olfaction in many respects of life. During courtship and nest building, male European starlings (Sturnus vulgaris incorporate aromatic herbs that are rich in volatile compounds (e.g., milfoil, Achillea millefolium into the nests and they use olfactory cues to identify these plants. Interestingly, European starlings show seasonal differences in their ability to respond to odour cues: odour sensitivity peaks during nest-building in the spring, but is almost non-existent during the non-breeding season. METHODOLOGY/PRINCIPAL FINDINGS: This study used repeated in vivo Manganese-enhanced MRI to quantify for the first time possible seasonal changes in the anatomy and activity of the OB in starling brains. We demonstrated that the OB of the starling exhibits a functional seasonal plasticity of certain plant odour specificity and that the OB is only able to detect milfoil odour during the breeding season. Volumetric analysis showed that this seasonal change in activity is not linked to a change in OB volume. By subsequently experimentally elevating testosterone (T in half of the males during the non-breeding season we showed that the OB volume was increased compared to controls. CONCLUSIONS/SIGNIFICANCE: By investigating the neural substrate of seasonal olfactory sensitivity changes we show that the starlings' OB loses its ability during the non-breeding season to detect a natural odour of a plant preferred as green nest material by male starlings. We found that testosterone, applied during the non-breeding season, does not restore the discriminatory ability of the OB but has an influence on its size.

  20. Olfactory neuroblastoma. The Hokkaido University experience

    International Nuclear Information System (INIS)

    Olfactory neuroblastoma is such a rare malignancy that no consensus has been reached on its management. We analyzed 17 patients with olfactory neuroblastoma treated between April 1980 and March 2004-9 men and 8 women, aged 16 to 76 years old (mean: 50.4 years). Follow-up of current survivors was 1 year 8 months to 16 years 6 months (average: 7 years 9 months). Initially, 2 were treated with surgery alone, 5 with surgery and radiotherapy, and 2 with a combination of these and chemotherapy. Without surgery, radiotherapy alone was conducted in 3 and combined of radiation and chemotherapy in 5. Three of the 5 patients treated with surgery and radiotherapy survive without locoregional recurrence as do 2 with chemotherapy added. All 5 initially treated with craniofacial resection survived more than 5 years. Combined radiotherapy and chemotherapy without surgery was effective in 2. 5- and 10-year overall survival for all patients were 75.5% and 64.7%. Overall 5-year survival of 8 patients with low-grade tumors was 87.5% and of 6 with high-grade tumors 33.3%. In conclusion, combined craniofacial resection plus radiotherapy and chemotherapy seemed to improve survival. Histopathological grading is a prognostic factors. (author)

  1. 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.  

  2. Cellular Architecture and Functional Aspects of the Olfactory Rosette of Wallago attu (Bleeker)

    OpenAIRE

    Ghosh, Saroj Kumar; Chakrabarti, Padmanabha

    2009-01-01

    The olfactory epithelium of Wallago attu has been studied with conventional histological techniques. The elongated olfactory rosette consists of 62 to 64 primary lamellae in each left and right rosette. The olfactory lamellae are arranged in two rows on either side of the long raphe. Each olfactory lamella consists of two layers of epithelium separated by central core. The olfactory epithelium in one side consists of mixed sensory and non-sensory epithelium while the other side is consists of...

  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)

    ElenaV.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. A lifetime of neurogenesis in the olfactory system.

    Science.gov (United States)

    Brann, Jessica H; Firestein, Stuart J

    2014-01-01

    Neurogenesis continues well beyond embryonic and early postnatal ages in three areas of the nervous system. The subgranular zone supplies new neurons to the dentate gyrus of the hippocampus. The subventricular zone supplies new interneurons to the olfactory bulb, and the olfactory neuroepithelia generate new excitatory sensory neurons that send their axons to the olfactory bulb. The latter two areas are of particular interest as they contribute new neurons to both ends of a first-level circuit governing olfactory perception. The vomeronasal organ and the main olfactory epithelium comprise the primary peripheral olfactory epithelia. These anatomically distinct areas share common features, as each exhibits extensive neurogenesis well beyond the juvenile phase of development. Here we will discuss the effect of age on the structural and functional significance of neurogenesis in the vomeronasal and olfactory epithelia, from juvenile to advanced adult ages, in several common model systems. We will next discuss how age affects the regenerative capacity of these neural stem cells in response to injury. Finally, we will consider the integration of newborn neurons into an existing circuit as it is modified by the age of the animal. PMID:25018692

  5. Expression of corticosteroid binding globulin in the rat olfactory system.

    Science.gov (United States)

    Dölz, Wilfried; Eitner, Annett; Caldwell, Jack D; Jirikowski, Gustav F

    2013-05-01

    Glucocorticoids are known to act on the olfactory system although their mode of action is still unclear since nuclear glucocorticoid receptors are mostly absent in the olfactory mucosa. In this study we used immunocytochemistry, in situ hybridization, and RT-PCR to study the expression and distribution of corticosteroid binding globulin (CBG) in the rat olfactory system. Mucosal goblet cells could be immunostained for CBG. Nasal secretion contained measurable amounts of CBG suggesting that CBG is liberated. CBG immunoreactivity was localized in many of the basal cells of the olfactory mucosa, while mature sensory cells contained CBG only in processes as determined by double immunostaining with the olfactory marker protein OMP. This staining was most pronounced in the vomeronasal organ (VNO). The appearance of CBG in the non-sensory and sensory parts of the VNO and in nerve terminals in the accessory bulb indicated axonal transport. Portions of the periglomerular cells, the mitral cells and the tufted cells were also CBG positive. CBG encoding transcripts were confirmed by RT-PCR in homogenates of the olfactory mucosa and VNO. Olfactory CBG may be significant for uptake, accumulation and transport of glucocorticoids, including aerosolic cortisol. PMID:23141917

  6. A lifetime of neurogenesis in the olfactory system

    Directory of Open Access Journals (Sweden)

    Jessica H. Brann

    2014-06-01

    Full Text Available Neurogenesis continues well beyond embryonic and early postnatal ages in three areas of the nervous system. The subgranular zone supplies new neurons to the dentate gyrus of the hippocampus. The subventricular zone supplies new interneurons to the olfactory bulb, and the olfactory neuroepithelia generates new excitatory sensory neurons that send their axons to the olfactory bulb. The latter two areas are of particular interest as they contribute new neurons to both ends of a first-level circuit governing olfactory perception. The vomeronasal organ and the main olfactory epithelium comprise the primary peripheral olfactory epithelia. These anatomically distinct areas share common features, as each exhibits extensive neurogenesis well beyond the juvenile phase of development. Here we will discuss the effect of age on the structural and functional significance of neurogenesis in the vomeronasal and olfactory epithelia, from juvenile to advanced adult ages, in several common model systems. We will next discuss how age affects the regenerative capacity of these neural stem cells in response to injury. Finally, we will consider the integration of newborn neurons into an existing circuit as it is modified by the age of the animal.

  7. Respiratory and olfactory turbinal size in canid and arctoid carnivorans.

    Science.gov (United States)

    Green, Patrick A; Van Valkenburgh, Blaire; Pang, Benison; Bird, Deborah; Rowe, Timothy; Curtis, Abigail

    2012-12-01

    Within the nasal cavity of mammals is a complex scaffold of paper-thin bones that function in respiration and olfaction. Known as turbinals, the bones greatly enlarge the surface area available for conditioning inspired air, reducing water loss, and improving olfaction. Given their functional significance, the relative development of turbinal bones might be expected to differ among species with distinct olfactory, thermoregulatory and/or water conservation requirements. Here we explore the surface area of olfactory and respiratory turbinals relative to latitude and diet in terrestrial Caniformia, a group that includes the canid and arctoid carnivorans (mustelids, ursids, procyonids, mephitids, ailurids). Using high-resolution computed tomography x-ray scans, we estimated respiratory and olfactory turbinal surface area and nasal chamber volume from three-dimensional virtual models of skulls. Across the Caniformia, respiratory surface area scaled isometrically with estimates of body size and there was no significant association with climate, as estimated by latitude. Nevertheless, one-on-one comparisons of sister taxa suggest that arctic species may have expanded respiratory turbinals. Olfactory surface area scaled isometrically among arctoids, but showed positive allometry in canids, reflecting the fact that larger canids, all of which are carnivorous, had relatively greater olfactory surface areas. In addition, among the arctoids, large carnivorous species such as the polar bear (Ursus maritimus) and wolverine (Gulo gulo) also displayed enlarged olfactory turbinals. More omnivorous caniform species that feed on substantial quantities of non-vertebrate foods had less expansive olfactory turbinals. Because large carnivorous species hunt widely dispersed prey, an expanded olfactory turbinal surface area may improve a carnivore's ability to detect prey over great distances using olfactory cues. PMID:23035637

  8. Maturation and Dysgenesis of the Human Olfactory Bulb.

    Science.gov (United States)

    Sarnat, Harvey B; Yu, Weiming

    2016-05-01

    The olfactory bulb with its unique architecture was studied for neuronal maturation in human fetuses. Neuroblasts stream into the olfactory bulb from the rostral telencephalon and secondarily migrate radially. The transitory olfactory ventricular recess regresses postnatally. Olfactory is the only sensory system without thalamic projections but incorporates intrinsic thalamic equivalents. The bulb is a repository of progenitor cells. Maturation of the bulb and tract was studied in 18 normal human fetuses of 16-41 weeks gestation; mid-gestational twins with hydrocephalus; 7 arrhinencephaly/holoprosencephaly; 2 olfactory dysgeneses. Multiple immunoreactivities were performed. Synaptophysin around mitral neurons, in a few synaptic glomeruli and concentric lamination of the outer granular layer, was seen at 16 weeks. Outer granular neurons exhibited NeuN at 16 weeks, only 2/3 were reactive at term. Concentric alternating sheets of granular neurons and their dendrodendritic synapses are seen during maturation. Calretinin reactivity is seen in neurons and neurites, primary olfactory nerve axons, periglomerular cells and neuroepithelial cells surrounding the ventricular recess; reactivity occurs later in synaptic glomeruli than with synaptophysin; not all glomeruli are strongly reactive even at term. Nestin- and vimentin-reactive bipolar progenitor cells were demonstrated at all ages and extend into the olfactory tract. Myelin is demonstrated by Luxol fast blue (LFB) only postnatally. In hydrocephalus, the olfactory recess is dilated. Mitral cell dispersion, disrupted glomeruli, heterotopia and maturational delay are seen in some dysgeneses. Malformations exhibit unique findings. Fusion of hypoplastic bulbs can occur. Abnormal architecture is seen in hemimegalencephaly. More documentation of olfactory dysgenesis is needed in other major brain malformations. PMID:26096058

  9. Value of MRI olfactory bulb evaluation in the assessment of olfactory dysfunction in Bardet-Biedl syndrome.

    Science.gov (United States)

    Braun, J J; Noblet, V; Kremer, S; Molière, S; Dollfus, H; Marion, V; Goetz, N; Muller, J; Riehm, S

    2016-07-01

    Olfactory bulb (OB) volume evaluation by magnetic resonance imaging (MRI) has been demonstrated to be related to olfactory dysfunction in many different diseases. Olfactory dysfunction is often overlooked in Bardet-Biedl syndrome (BBS) patients and is rarely objectively evaluated by MRI. We present a series of 20 BBS patients with olfactory dysfunction. The OB was evaluated separately and blindly by two radiologists (SR and SM) with 3 Tesla MRI imaging comparatively to 12 normal control subjects by global visual evaluation and by quantitative measurement of OB volume. In the 12 control cases OB visual evaluation was considered as normal in all cases for radiologist (SR) and in 10 cases for radiologist (SM). In the 20 BBS patients, OB visual evaluation was considered as abnormal in 18 cases for SR and in all cases for SM. OB volumetric evaluation for SR and SM in BBS patients was able to provide significant correlation between BBS and olfactory dysfunction. This study indicates that OB volume evaluation by MRI imaging like structural MRI scan for gray matter modifications demonstrates that olfactory dysfunction in BBS patients is a constant and cardinal symptom integrated in a genetical syndrome with peripheral and central olfactory structure alterations. PMID:26586152

  10. Intramodal Olfactory Priming of Positive and Negative Odors in Humans Using Respiration-Triggered Olfactory Stimulation (RETROS).

    Science.gov (United States)

    Hoffmann-Hensel, Sonja Maria; Freiherr, Jessica

    2016-09-01

    Priming describes the principle of modified stimulus perception that occurs due to a previously presented stimulus. Although we have begun to understand the mechanisms of crossmodal priming, the concept of intramodal olfactory priming remains relatively unexplored. Therefore, we applied positive and negative odors using respiration-triggered olfactory stimulation (RETROS), enabling us to record the skin conductance response (SCR) and breathing data without a crossmodal cueing error and measure reaction times (RTs) for olfactory tasks. RT, SCR, and breathing data revealed that negative odors were perceived significantly more arousing than positive ones. In a second experiment, 2 odors were applied during consecutive respirations. Here, we observed intramodal olfactory priming effects: A negative odor preceded by a positive odor was rated as more pleasant than when the same odor was preceded by a negative odor. Additionally, a longer identification RT was found for the second compared with the first odor. We interpret this as increased "perceptual load" due to incomplete first odor processing while the second odor was presented. Furthermore, intramodal priming can be considered a possible reason for the increase of identification RT. The use of RETROS led to these novel insights into olfactory processing beyond crossmodal interaction by providing a noncued unimodal olfactory test, and therefore, RETROS can be used in the experimental design of future olfactory studies. PMID:27170666

  11. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like...

  12. Interactions with the young down-regulate adult olfactory neurogenesis and enhance the maturation of olfactory neuroblasts in sheep mothers.

    Directory of Open Access Journals (Sweden)

    Frédéric Levy

    2014-02-01

    Full Text Available New neurons are continuously added in the dentate gyrus and the olfactory bulb of mammalian brain. While numerous environmental factors controlling survival of newborn neurons have been extensively studied, regulation by social interactions is less documented. We addressed this question by investigating the influence of parturition and interactions with the young on neurogenesis in sheep mothers. Using Bromodeoxyuridine, a marker of cell division, in combination with markers of neuronal maturation, the percentage of neuroblasts and new mature neurons in the olfactory bulb and the dentate gyrus was compared between groups of parturient ewes which could interact or not with their lamb, and virgins. In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures. We showed that the post-partum period was associated with a decrease in olfactory and hippocampal adult neurogenesis. In the olfactory bulb, the suppressive effect on neuroblasts was dependent on interactions with the young whereas in the dentate gyrus the decrease in new mature neurons was associated with parturition. In addition, dendritic length and number of nodes of neuroblasts were significantly enhanced by interactions with the lamb in the olfactory bulb but not in the dentate gyrus. Because interactions with the young involved learning of the olfactory signature of the lamb, we hypothesize that this learning is associated with a down-regulation in olfactory neurogenesis and an enhancement of olfactory neuroblast maturation. Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor.

  13. Interactions with the young down-regulate adult olfactory neurogenesis and enhance the maturation of olfactory neuroblasts in sheep mothers.

    Science.gov (United States)

    Brus, Maïna; Meurisse, Maryse; Keller, Matthieu; Lévy, Frédéric

    2014-01-01

    New neurons are continuously added in the dentate gyrus (DG) and the olfactory bulb of mammalian brain. While numerous environmental factors controlling survival of newborn neurons have been extensively studied, regulation by social interactions is less documented. We addressed this question by investigating the influence of parturition and interactions with the young on neurogenesis in sheep mothers. Using Bromodeoxyuridine, a marker of cell division, in combination with markers of neuronal maturation, the percentage of neuroblasts and new mature neurons in the olfactory bulb and the DG was compared between groups of parturient ewes which could interact or not with their lamb, and virgins. In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures. We showed that the postpartum period was associated with a decrease in olfactory and hippocampal adult neurogenesis. In the olfactory bulb, the suppressive effect on neuroblasts was dependent on interactions with the young whereas in the DG the decrease in new mature neurons was associated with parturition. In addition, dendritic length and number of nodes of neuroblasts were significantly enhanced by interactions with the lamb in the olfactory bulb but not in the DG. Because interactions with the young involved learning of the olfactory signature of the lamb, we hypothesize that this learning is associated with a down-regulation in olfactory neurogenesis and an enhancement of olfactory neuroblast maturation. Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor. PMID:24600367

  14. Fault tolerant architecture for artificial olfactory system

    International Nuclear Information System (INIS)

    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)

  15. Coding and transformations in the olfactory system.

    Science.gov (United States)

    Uchida, Naoshige; Poo, Cindy; Haddad, Rafi

    2014-01-01

    How is sensory information represented in the brain? A long-standing debate in neural coding is whether and how timing of spikes conveys information to downstream neurons. Although we know that neurons in the olfactory bulb (OB) exhibit rich temporal dynamics, the functional relevance of temporal coding remains hotly debated. Recent recording experiments in awake behaving animals have elucidated highly organized temporal structures of activity in the OB. In addition, the analysis of neural circuits in the piriform cortex (PC) demonstrated the importance of not only OB afferent inputs but also intrinsic PC neural circuits in shaping odor responses. Furthermore, new experiments involving stimulation of the OB with specific temporal patterns allowed for testing the relevance of temporal codes. Together, these studies suggest that the relative timing of neuronal activity in the OB conveys odor information and that neural circuits in the PC possess various mechanisms to decode temporal patterns of OB input. PMID:24905594

  16. 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. PMID:19577476

  17. 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.

  18. An enigmatic clinical entity: A new case of olfactory schwannoma.

    Science.gov (United States)

    Manto, Andrea; Manzo, Gaetana; De Gennaro, Angela; Martino, Vincenzo; Buono, Vincenzo; Serino, Antonietta

    2016-06-01

    Olfactory schwannomas, also described as subfrontal or olfactory groove schwannomas, are very rare tumors, whose pathogenesis is still largely debated. We report a case of olfactory schwannoma in a 39-year-old woman who presented with anosmia and headache. The clinical examination did not show lesions in the nose-frontal region and there was no history of neurofibromatosis. Head MRI and CT scan revealed a lobulated extra-axial mass localized in the right anterior cranial fossa that elevated the ipsilateral frontal pole. Bilateral frontal craniotomy demonstrated a tumor strictly attached to the right portion of the cribriform plate that surrounded the right olfactory tract, not clearly identifiable. The immunohistochemical analysis suggested the diagnosis of typical schwannoma. The patient was discharged without any neurological deficit and a four-month postoperative MRI scan of the brain showed no residual or recurrent tumor. PMID:26944065

  19. Bilateral Synchronous Ectopic Ethmoid Sinus Olfactory Neuroblastoma: A Case Report.

    Science.gov (United States)

    Leon-Soriano, Elena; Alfonso, Carolina; Yebenes, Laura; Garcia-Polo, Julio; Lassaletta, Luis; Gavilan, Javier

    2016-01-01

    BACKGROUND Olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma, is a rare malignant head and neck cancer thought to originate from the olfactory epithelium. It typically invades contiguous structures at presentation. We report a very rare case of multifocal and ectopic ONB. CASE REPORT A 41-year-old man presented with left nasal obstruction and occasional left epistaxis associated with headache. Endoscopic examination of the nasal cavities and computed tomography suggested bilateral polypoid masses. Histopathological diagnosis after endoscopic resection established bilateral olfactory neuroblastoma of the ethmoid sinuses. The patient received postoperative radiotherapy. He remains free of disease 4 years after treatment. CONCLUSIONS To the best of our knowledge this is the second documented case of multifocal ectopic olfactory neuroblastoma. Clinicians should consider ONB in the differential diagnosis of bilateral synchronous nasal and paranasal masses to avoid delayed diagnosis. Endoscopic resection of ONB could be an option in selected cases. PMID:27097989

  20. Olfactory communication among Costa Rican squirrel monkeys: a field study.

    Science.gov (United States)

    Boinski, S

    1992-01-01

    Behaviors with a possible role in olfactory communication among troop members were investigated as part of a field study on the reproductive and foraging ecology of squirrel monkeys (Saimiri oerstedi) in Costa Rica. All age classes engaged in the olfaction-related behaviors. Apart from olfactory investigation of female genitals by males during the mating season, no other potential olfaction-related behavior (urine wash, branch investigation, rump, chest, back rub and sneeze) exceeded 1% of mean behavioral samples. Assessment of reproduction condition appears to be the primary function of such olfactory investigation of the female genital region. The primary function of urine washing is suggested to be the general communication of reproductive status, possibly facilitating reproductive synchrony. Sneezing, rump, back and chest rubbing do not appear to deposit substances active in olfactory communication. PMID:1306175

  1. Unravelling the Olfactory Sense: From the Gene to Odor Perception.

    Science.gov (United States)

    Silva Teixeira, Carla S; Cerqueira, Nuno M F S A; Silva Ferreira, António C

    2016-02-01

    Although neglected by science for a long time, the olfactory sense is now the focus of a panoply of studies that bring new insights and raises interesting questions regarding its functioning. The importance in the clarification of this process is of interest for science, but also motivated by the food and perfume industries boosted by a consumer society with increasingly demands for higher quality standards. In this review, a general overview of the state of art of science regarding the olfactory sense is presented with the main focus on the peripheral olfactory system. Special emphasis will be given to the deorphanization of the olfactory receptors (ORs), a critical issue because the specificity and functional properties of about 90% of human ORs remain unknown mainly due to the difficulties associated with the functional expression of ORs in high yields. PMID:26688501

  2. The muted sense: neurocognitive limitations of olfactory language.

    Science.gov (United States)

    Olofsson, Jonas K; Gottfried, Jay A

    2015-06-01

    Most people find it profoundly difficult to name familiar smells. This difficulty persists even when perceptual odor processing and visual object naming are unimpaired, implying deficient sensory-specific interactions with the language system. Here we synthesize recent behavioral and neuroimaging data to develop a biologically informed framework for olfactory lexical processing in the human brain. Our central premise is that the difficulty in naming common objects through olfactory (compared with visual) stimulation is the end result of cumulative effects occurring at three successive stages of the olfactory language pathway: object perception, lexical-semantic integration, and verbalization. Understanding the neurocognitive mechanisms by which the language network interacts with olfaction can yield unique insights into the elusive nature of olfactory naming. PMID:25979848

  3. Olfactory Predictive Codes and Stimulus Templates in Piriform Cortex

    OpenAIRE

    Zelano, Christina; Mohanty, Aprajita; Gottfried, Jay A.

    2011-01-01

    Neuroscientific models of sensory perception suggest that the brain utilizes predictive codes in advance of a stimulus encounter, enabling organisms to infer forthcoming sensory events. However, it is poorly understood how such mechanisms are implemented in the olfactory system. Combining high-resolution functional magnetic resonance imaging with multivariate (pattern-based) analyses, we examined the spatiotemporal evolution of odor perception in the human brain during an olfactory search tas...

  4. 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.

  5. Viral disruption of olfactory progenitors is exacerbated in allergic mice

    OpenAIRE

    Ueha, R.; Mukherjee, S.; Ueha, S.; de Almeida Nagata, D.E.; Sakamoto, T.; K. Kondo; Yamasoba, T.; Lukacs, N W; Kunkel, S. L.

    2014-01-01

    Upper airway viral infection in patients with airway allergy often exacerbates olfactory dysfunction, but the mechanism for this exacerbation remains unclear. Here, we examined the effects of respiratory syncytial virus (RSV) infection, in the presence or absence of airway allergy, on olfactory receptor neurons (ORNs) and their progenitors in mice. Immunohistological analyses revealed that cockroach allergen (CRA)-induced airway allergy alone did not affect the number of OMP+ mature ORNs and ...

  6. Neural crest and placode contributions to olfactory development.

    Science.gov (United States)

    Suzuki, Jun; Osumi, Noriko

    2015-01-01

    Olfaction is the sense of smell that influences many primitive behaviors for survival, e.g., feeding, reproduction, social interaction, and fear response. The olfactory system is an evolutionarily ancient sensory system and composed of the olfactory epithelium (OE), the olfactory bulb (OB), and the olfactory cortex. The OE gives rise to olfactory receptor neurons (ORNs), i.e., primary sensory receptor cells whose axons project directly to the OB. The ORNs are unique in the way that they are continuously replaced during physiological turnover or following injury throughout life. In the OE, horizontal basal cells, i.e., flat and quiescent cells attached to the basal lamina, are now thought to be tissue stem cells. Although OE cells, especially ORNs, were hypothesized to be derived from the olfactory placode (OP), recent genetic fate-mapping studies using Cre reporter mice indicate a dual origin, i.e., the OP and neural crest (NC), of the olfactory system. The NC is a transient embryonic tissue that is formed between the dorsal neuroepithelium and epidermis. Neural crest cells (NCCs) are multipotent cells that migrate into various target tissues and differentiate into various cell types, including neurons and glia of the peripheral nervous system, cranial cartilage and bone, and melanocytes. Recent studies have revealed that neural crest-derived cells (NCDCs) are widely distributed in adult tissues, and that a subset of NCDCs still possesses NCC-like multipotency. Here, we review classical and recent studies of the olfactory system, especially focusing on the contribution of the NC and OP to the OE development. PMID:25662265

  7. Complementary sensory and associative microcircuitry in primary olfactory cortex

    OpenAIRE

    Wiegand, H.F.; Beed, P.; Bendels, M.H.; Leibold, C.; Schmitz, D; Johenning, F.W.

    2011-01-01

    The three-layered primary olfactory (piriform) cortex is the largest component of the olfactory cortex. Sensory and intracortical inputs converge on principal cells in the anterior piriform cortex (aPC). We characterize organization principles of the sensory and intracortical microcircuitry of layer II and III principal cells in acute slices of rat aPC using laser-scanning photostimulation and fast two-photon population Ca(2+) imaging. Layer II and III principal cells are set up on a superfic...

  8. Olfactory Impairment in Adults: The Beaver Dam Experience

    OpenAIRE

    Schubert, Carla R.; Cruickshanks, Karen J.; Murphy, Claire; Huang, Guan-Hua; Klein, Barbara E K; KLEIN,Ronald; Nieto, F Javier; James S. Pankow; Tweed, Ted S

    2009-01-01

    Olfactory function may be important for environmental and nutritional safety and enjoyment. Population-based epidemiologic studies of olfaction are needed to understand the magnitude of the health burden, identify modifiable risk factors and develop and test prevention and treatment strategies for olfactory impairment. However, measuring olfaction in large studies is challenging, requiring repeatable, efficient methods which can measure change over time. Two large cohort studies, the Epidemio...

  9. Deep sequencing of the murine olfactory receptor neuron transcriptome.

    Directory of Open Access Journals (Sweden)

    Ninthujah Kanageswaran

    Full Text Available The ability of animals to sense and differentiate among thousands of odorants relies on a large set of olfactory receptors (OR and a multitude of accessory proteins within the olfactory epithelium (OE. ORs and related signaling mechanisms have been the subject of intensive studies over the past years, but our knowledge regarding olfactory processing remains limited. The recent development of next generation sequencing (NGS techniques encouraged us to assess the transcriptome of the murine OE. We analyzed RNA from OEs of female and male adult mice and from fluorescence-activated cell sorting (FACS-sorted olfactory receptor neurons (ORNs obtained from transgenic OMP-GFP mice. The Illumina RNA-Seq protocol was utilized to generate up to 86 million reads per transcriptome. In OE samples, nearly all OR and trace amine-associated receptor (TAAR genes involved in the perception of volatile amines were detectably expressed. Other genes known to participate in olfactory signaling pathways were among the 200 genes with the highest expression levels in the OE. To identify OE-specific genes, we compared olfactory neuron expression profiles with RNA-Seq transcriptome data from different murine tissues. By analyzing different transcript classes, we detected the expression of non-olfactory GPCRs in ORNs and established an expression ranking for GPCRs detected in the OE. We also identified other previously undescribed membrane proteins as potential new players in olfaction. The quantitative and comprehensive transcriptome data provide a virtually complete catalogue of genes expressed in the OE and present a useful tool to uncover candidate genes involved in, for example, olfactory signaling, OR trafficking and recycling, and proliferation.

  10. 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. PMID:27194792

  11. Searching for learning-dependent changes in the antennal lobe: simultaneous recording of neural activity and aversive olfactory learning in honeybees

    Directory of Open Access Journals (Sweden)

    Edith Roussel

    2010-09-01

    Full Text Available Plasticity in the honeybee brain has been studied using the appetitive olfactory conditioning of the proboscis extension reflex, in which a bee learns the association between an odor and a sucrose reward. In this framework, coupling behavioral measurements of proboscis extension and invasive recordings of neural activity has been difficult because proboscis movements usually introduce brain movements that affect physiological preparations. Here we took advantage of a new conditioning protocol, the aversive olfactory conditioning of the sting extension reflex, which does not generate this problem. We achieved the first simultaneous recordings of conditioned sting extension responses and calcium imaging of antennal lobe activity, thus revealing on-line processing of olfactory information during conditioning trials. Based on behavioral output we distinguished learners and non-learners and analyzed possible learning-dependent changes in antennal lobe activity. We did not find differences between glomerular responses to the CS+ and the CS- in learners. Unexpectedly, we found that during conditioning trials non-learners exhibited a progressive decrease in physiological responses to odors, irrespective of their valence. This effect could neither be attributed to a fitness problem nor to abnormal dye bleaching. We discuss the absence of learning-induced changes in the antennal lobe of learners and the decrease in calcium responses found in non-learners. Further studies will have to extend the search for functional plasticity related to aversive learning to other brain areas and to look on a broader range of temporal scales

  12. Phospholipase C and Diacylglycerol Mediate Olfactory Responses to Amino Acids in the Main Olfactory Epithelium of an Amphibian

    OpenAIRE

    Alfredo Sansone; Thomas Hassenklöver; Syed, Adnan S; Sigrun I. Korsching; Ivan Manzini

    2014-01-01

    The semi-aquatic lifestyle of amphibians represents a unique opportunity to study the molecular driving forces involved in the transition of aquatic to terrestrial olfaction in vertebrates. Most amphibians have anatomically segregated main and vomeronasal olfactory systems, but at the cellular and molecular level the segregation differs from that found in mammals. We have recently shown that amino acid responses in the main olfactory epithelium (MOE) of larval Xenopus laevis segregate into a ...

  13. Olfactory Impairment and Subjective Olfactory Complaints Independently Predict Conversion to Dementia : A Longitudinal, Population-Based Study

    OpenAIRE

    Stanciu, Ingrid; Larsson, Maria; Nordin, Steven; ADOLFSSON, ROLF; Nilsson, Lars-Goran; Olofsson, Jonas K.

    2014-01-01

    We examined whether conversion to dementia can be predicted by self-reported olfactory impairment and/or by an inability to identify odors. Common forms of dementia involve an impaired sense of smell, and poor olfactory performance predicts cognitive decline among the elderly. We followed a sample of 1529 participants, who were within a normal range of overall cognitive function at baseline, over a 10-year period during which 159 were classified as having a dementia disorder. Dementia convers...

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

    International Nuclear Information System (INIS)

    Accumulation of [35S]taurine in the laminae of the olfactory bulb of the adult cat, rat, mouse and rabbit was examined autoradiographically. [35S]Taurine was administered either i.p. or i.v. and olfactory bulbs were excised 24 h post-injection. High concentrations of [35S]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.)

  15. 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

  16. 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.

  17. Plasticity and Geotechnics

    Science.gov (United States)

    Yu, Hai-Sui

    Plasticity and Geotechnics is the first attempt to summarize and present, in one volume, the major developments achieved to date in the field of plasticity theory for geotechnical materials and its applications to geotechnical analysis and design.

  18. Neural representations of novel objects associated with olfactory experience.

    Science.gov (United States)

    Ghio, Marta; Schulze, Patrick; Suchan, Boris; Bellebaum, Christian

    2016-07-15

    Object conceptual knowledge comprises information related to several motor and sensory modalities (e.g. for tools, how they look like, how to manipulate them). Whether and to which extent conceptual object knowledge is represented in the same sensory and motor systems recruited during object-specific learning experience is still a controversial question. A direct approach to assess the experience-dependence of conceptual object representations is based on training with novel objects. The present study extended previous research, which focused mainly on the role of manipulation experience for tool-like stimuli, by considering sensory experience only. Specifically, we examined the impact of experience in the non-dominant olfactory modality on the neural representation of novel objects. Sixteen healthy participants visually explored a set of novel objects during the training phase while for each object an odor (e.g., peppermint) was presented (olfactory-visual training). As control conditions, a second set of objects was only visually explored (visual-only training), and a third set was not part of the training. In a post-training fMRI session, participants performed an old/new task with pictures of objects associated with olfactory-visual and visual-only training (old) and no training objects (new). Although we did not find any evidence of activations in primary olfactory areas, the processing of olfactory-visual versus visual-only training objects elicited greater activation in the right anterior hippocampus, a region included in the extended olfactory network. This finding is discussed in terms of different functional roles of the hippocampus in olfactory processes. PMID:27083305

  19. Expression of olfactory signaling genes in the eye.

    Directory of Open Access Journals (Sweden)

    Alexey Pronin

    Full Text Available PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

  20. Using insect electroantennogram sensors on autonomous robots for olfactory searches.

    Science.gov (United States)

    Martinez, Dominique; Arhidi, Lotfi; Demondion, Elodie; Masson, Jean-Baptiste; Lucas, Philippe

    2014-01-01

    Robots designed to track chemical leaks in hazardous industrial facilities or explosive traces in landmine fields face the same problem as insects foraging for food or searching for mates: the olfactory search is constrained by the physics of turbulent transport. The concentration landscape of wind borne odors is discontinuous and consists of sporadically located patches. A pre-requisite to olfactory search is that intermittent odor patches are detected. Because of its high speed and sensitivity, the olfactory organ of insects provides a unique opportunity for detection. Insect antennae have been used in the past to detect not only sex pheromones but also chemicals that are relevant to humans, e.g., volatile compounds emanating from cancer cells or toxic and illicit substances. We describe here a protocol for using insect antennae on autonomous robots and present a proof of concept for tracking odor plumes to their source. The global response of olfactory neurons is recorded in situ in the form of electroantennograms (EAGs). Our experimental design, based on a whole insect preparation, allows stable recordings within a working day. In comparison, EAGs on excised antennae have a lifetime of 2 hr. A custom hardware/software interface was developed between the EAG electrodes and a robot. The measurement system resolves individual odor patches up to 10 Hz, which exceeds the time scale of artificial chemical sensors. The efficiency of EAG sensors for olfactory searches is further demonstrated in driving the robot toward a source of pheromone. By using identical olfactory stimuli and sensors as in real animals, our robotic platform provides a direct means for testing biological hypotheses about olfactory coding and search strategies. It may also prove beneficial for detecting other odorants of interests by combining EAGs from different insect species in a bioelectronic nose configuration or using nanostructured gas sensors that mimic insect antennae. PMID:25145980

  1. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin;

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example...

  2. STUDY OF PLASTIC SURGERY

    OpenAIRE

    Shrutika Sarangi

    2015-01-01

    Plastic surgery is a therapeutic system with the motivation behind modification or restoring the body's type. In spite of the fact that corrective or stylish surgery is the most surely understood sort of plastic surgery, plastic surgery itself is not inexorably considered cosmetic; and incorporates numerous sorts of reconstructive surgery, craniofacial surgery, hand surgery, microsurgery, and the treatment of smolders.

  3. Chemical Recycle of Plastics

    Directory of Open Access Journals (Sweden)

    Sara Fatima

    2014-11-01

    Full Text Available Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle

  4. Volumetric study of the olfactory bulb in patients with chronic rhinonasal sinusitis using MRI

    Directory of Open Access Journals (Sweden)

    Reda A. Alarabawy

    2016-06-01

    Conclusions: MRI with volumetric analysis is a useful tool in assessment of the olfactory bulb volume in patients with olfactory loss and appears to be of help in assessment of the degree of recovery in patients after sinus surgery.

  5. Effects of olfactory sense on chocolate craving.

    Science.gov (United States)

    Firmin, Michael W; Gillette, Aubrey L; Hobbs, Taylor E; Wu, Di

    2016-10-01

    In the present study, we assessed the effect of the olfactory sense on chocolate craving in college females. Building on previous research by Kemps and Tiggemann (2013), we hypothesized that a fresh scent would decrease one's craving level for chocolate food. While the precursor study only addressed the decrease of chocolate craving, we also hypothesized that a sweet scent would increase one's craving level for chocolate foods. In the present experiment, participants rated their craving levels after viewing images of chocolate foods and inhaling essential oils: one fresh (Slique™ essence), and one sweet (vanilla). Results supported both of the hypotheses: inhaling a fresh scent reduced females' craving levels; similarly, when a sweet scent was inhaled, the participants' craving levels for chocolate food increased. These findings are particularly beneficial for women seeking weight loss and the findings can be applied in contexts such as weight loss programs, therapy, and maintenance programs, even beyond college settings. The results are particularly useful for helping women regarding stimuli that might serve as triggers for chocolate cravings. PMID:27395410

  6. Olfactory instruction for fear: neural system analysis.

    Directory of Open Access Journals (Sweden)

    Newton Sabino Canteras

    2015-08-01

    Full Text Available Studies using cat odor have led to detailed mapping of neural sites engaged in innate and contextual fear responses. Here, we reviewed three lines of work examining the dynamics of the neural systems that organize innate and learned fear responses to cat odor. In the first, we explored the neural systems involved in innate fear responses and in the different stages of fear conditioning to cat odor (i.e., acquisition and expression, with a particular emphasis on the role of the dorsal premammillary nucleus (PMd and the dorsolateral periaqueductal gray (PAGdl as key sites that influence innate and contextual conditioning. In the second line of studies, we reviewed how chemical stimulation of these sites (i.e., the PMd and PAGdl may serve as a useful unconditioned stimulus in an olfactory fear conditioning paradigm; these experiments provide an interesting perspective for the understanding of learned fear to predator odor. Finally, in the third line of studies, we explored the fact that neutral odors that acquire an aversive valence in a shock-paired conditioning paradigm may mimic predator odor and mobilize elements of the hypothalamic predator-responsive circuit.

  7. Olfactory responses of blowflies to aliphatic aldehydes.

    Science.gov (United States)

    DETHIER, V G

    1954-07-20

    The response of the blowfly Phormia regina to stimulation by aldehydes in the vapor phase has been studied by means of a specially designed olfactometer. The median rejection threshold and the maximum acceptance threshold were selected as criteria of response. For both acceptance and rejection the distribution of thresholds in the population is normal with respect to the logarithm of concentration. When thresholds are expressed as molar concentrations, the values decrease progressively as chain length is increased. There is no attraction beyond decanal and no rejection beyond dodecanal. When thresholds are expressed as activities, most members of the aldehyde series are approximately equally stimulating at rejection and equally stimulating at acceptance. The relationship is most exact over the middle range of chain lengths. There is a tendency for the terminal members to stimulate at higher activities. These relationships are in close agreement with those which were found earlier to apply to the normal aliphatic alcohols. The similarity between the relative actions of the members of the two series suggests that the relation of equal olfactory stimulation at equal thermodynamic activities by homologous aliphatic compounds at least for homologues of intermediate chain length may be of rather general application in olfaction. PMID:13174780

  8. Farnesol-Detecting Olfactory Neurons in Drosophila

    Science.gov (United States)

    Ronderos, David S.; Lin, Chun-Chieh; Potter, Christopher J.

    2014-01-01

    We set out to deorphanize a subset of putative Drosophila odorant receptors expressed in trichoid sensilla using a transgenic in vivo misexpression approach. We identified farnesol as a potent and specific activator for the orphan odorant receptor Or83c. Farnesol is an intermediate in juvenile hormone biosynthesis, but is also produced by ripe citrus fruit peels. Here, we show that farnesol stimulates robust activation of Or83c-expressing olfactory neurons, even at high dilutions. The CD36 homolog Snmp1 is required for normal farnesol response kinetics. The neurons expressing Or83c are found in a subset of poorly characterized intermediate sensilla. We show that these neurons mediate attraction behavior to low concentrations of farnesol and that Or83c receptor mutants are defective for this behavior. Or83c neurons innervate the DC3 glomerulus in the antennal lobe and projection neurons relaying information from this glomerulus to higher brain centers target a region of the lateral horn previously implicated in pheromone perception. Our findings identify a sensitive, narrowly tuned receptor that mediates attraction behavior to farnesol and demonstrates an effective approach to deorphanizing odorant receptors expressed in neurons located in intermediate and trichoid sensilla that may not function in the classical “empty basiconic neuron” system. PMID:24623773

  9. The development of the olfactory organs in newly hatched monotremes and neonate marsupials.

    Science.gov (United States)

    Schneider, Nanette Yvette

    2011-08-01

    Olfactory cues are thought to play a crucial role in the detection of the milk source at birth in mammals. It has been shown that a marsupial, the tammar wallaby, can detect olfactory cues from its mother's pouch at birth. This study investigates whether the main olfactory and accessory olfactory system are similarly well developed in other marsupials and monotremes at birth/hatching as in the tammar. Sections of the head of various marsupial and two monotreme species were investigated by light microscopy. Both olfactory systems were less well developed in the kowari and Eastern quoll. No olfactory or vomeronasal or terminal nerves could be observed; the main olfactory bulb (MOB) had only two layers while no accessory olfactory bulb or ganglion terminale were visible. All other investigated marsupials and monotremes showed further developed olfactory systems with olfactory, vomeronasal and terminal nerves, a three-layered MOB, and in the marsupials a prominent ganglion terminale. The main olfactory system was further developed than the accessory olfactory system in all species investigated. The olfactory systems were the least developed in species in which the mother's birth position removed most of the difficulty in reaching the teat, placing the neonate directly in the pouch. In monotremes they were the furthest developed as Bowman glands were found underlying the main olfactory epithelium. This may reflect the need to locate the milk field each time they drink as they cannot permanently attach to it, unlike therian mammals. While it still needs to be determined how an odour signal could be further processed in the brain, this study suggests that marsupials and monotremes possess well enough developed olfactory systems to be able to detect an odour cue from the mammary area at birth/hatching. It is therefore likely that neonate marsupials and newly hatched monotremes find their way to the milk source using olfactory cues, as has been previously suggested for the

  10. The Olfactory Transcriptome and Progression of Sexual Maturation in Homing Chum Salmon Oncorhynchus keta

    OpenAIRE

    Palstra, A.P.; Fukaya, K.; Chiba, H; Dirks, R.P.; Planas, J.V.; Ueda, H

    2015-01-01

    Reproductive homing migration of salmonids requires accurate interaction between the reception of external olfactory cues for navigation to the spawning grounds and the regulation of sexual maturation processes. This study aimed at providing insights into the hypothesized functional link between olfactory sensing of the spawning ground and final sexual maturation. We have therefore assessed the presence and expression levels of olfactory genes by RNA sequencing (RNAseq) of the olfactory roset...

  11. Long-term Results of Stellate Ganglion Block in Patients with Olfactory Dysfunction

    OpenAIRE

    Moon, Ho Sik; Chon, Jin Young; Lee, Sang Hoon; Ju, Yu Mi; Sung, Choon Ho

    2013-01-01

    Background Olfactory dysfunction, including anosmia and hyposmia is difficult to treat. Although the mechanism is not well known, stellate ganglion block (SGB) is used to treat olfactory dysfunction. There are no prior studies on the long-term effects of SGB on olfactory dysfunction. The purpose of this study was to evaluate the continuity of therapeutic effects and patient satisfaction with SGB treatment. Methods This was a follow-up study carried out via a telephonic survey. The olfactory f...

  12. Physiological and morphological characterization of honeybee olfactory neurons combining electrophysiology, calcium imaging and confocal microscopy

    OpenAIRE

    Galizia, Cosmas Giovanni; Kimmerle, B.

    2004-01-01

    The insect antennal lobe is the first brain structure to process olfactory information. Like the vertebrate olfactory bulb the antennal lobe is substructured in olfactory glomeruli. In insects, glomeruli can be morphologically identified, and have characteristic olfactory response profiles. Local neurons interconnect glomeruli, and output (projection) neurons project to higher-order brain centres. The relationship between their elaborate morphology and their physiology is not understood. We r...

  13. EFFECTS OF MUTANT DROSOPHILA K+ CHANNEL SUBUNITS ON HABITUATION OF THE OLFACTORY JUMP RESPONSE

    OpenAIRE

    Joiner, M. A.; ASZTALOS, Z.; Jones, C. J.; Tully, T.; Wu, C.-F.

    2007-01-01

    The olfactory-jump response assay was used to analyze habituation in Drosophila mutants of potassium (K+) channel subunits. As with physiological assays of the giant fiber-mediated escape reflex, mutations at loci that encode K+ channel subunits have distinct effects on habituating the olfactory-jump response. The data for slowpoke and ether à go-go indicate similar effects on habituation of the olfactory-jump response and the giant fiber-mediated escape. Habituation in the olfactory jump ass...

  14. Evolutionary Genomics of Genes Involved in Olfactory Behavior in the Drosophila melanogaster Species Group

    OpenAIRE

    Nicolás Lavagnino; François Serra; Leonardo Arbiza; Hernán Dopazo; Esteban Hasson

    2012-01-01

    Previous comparative genomic studies of genes involved in olfactory behavior in Drosophila focused only on particular gene families such as odorant receptor and/or odorant binding proteins. However, olfactory behavior has a complex genetic architecture that is orchestrated by many interacting genes. In this paper, we present a comparative genomic study of olfactory behavior in Drosophila including an extended set of genes known to affect olfactory behavior. We took advantage of the recent bur...

  15. Dog and mouse: toward a balanced view of the mammalian olfactory system

    OpenAIRE

    Ignacio Salazar

    2014-01-01

    Although the most intensively studied mammalian olfactory system is that of the mouse, in which olfactory chemical cues of one kind or another are detected in four different nasal areas (the main olfactory epithelium, the septal organ, Grüneberg’s ganglion, and the sensory epithelium of the vomeronasal organ), the extraordinarily sensitive olfactory system of the dog is also an important model that is increasingly used, for example in genomic studies of species evolution. Here we describe the...

  16. Reliable Sex and Strain Discrimination in the Mouse Vomeronasal Organ and Accessory Olfactory Bulb

    OpenAIRE

    Tolokh, Illya I.; Fu, Xiaoyan; Holy, Timothy E.

    2013-01-01

    Animals modulate their courtship and territorial behaviors in response to olfactory cues produced by other animals. In rodents, detecting these cues is the primary role of the accessory olfactory system (AOS). We sought to systematically investigate the natural stimulus coding logic and robustness in neurons of the first two stages of accessory olfactory processing, the vomeronasal organ (VNO) and accessory olfactory bulb (AOB). We show that firing rate responses of just a few well-chosen mou...

  17. Olfactory insights into sleep-dependent learning and memory.

    Science.gov (United States)

    Shanahan, Laura K; Gottfried, Jay A

    2014-01-01

    Sleep is pervasive throughout most of the animal kingdom-even jellyfish and honeybees do it. Although the precise function of sleep remains elusive, research increasingly suggests that sleep plays a key role in memory consolidation. Newly formed memories are highly labile and susceptible to interference, and the sleep period offers an optimal window in which memories can be strengthened or modified. Interestingly, a small but growing research area has begun to explore the ability of odors to modulate memories during sleep. The unique anatomical organization of the olfactory system, including its intimate overlap with limbic systems mediating emotion and memory, and the lack of a requisite thalamic intermediary between the nasal periphery and olfactory cortex, suggests that odors may have privileged access to the brain during sleep. Indeed, it has become clear that the long-held assumption that odors have no impact on the sleeping brain is no longer tenable. Here, we summarize recent studies in both animal and human models showing that odor stimuli experienced in the waking state modulate olfactory cortical responses in sleep-like states, that delivery of odor contextual cues during sleep can enhance declarative memory and extinguish fear memory, and that olfactory associative learning can even be achieved entirely within sleep. Data reviewed here spotlight the emergence of a new research area that should hold far-reaching implications for future neuroscientific investigations of sleep, learning and memory, and olfactory system function. PMID:24767488

  18. Infection of Wolbachia may improve the olfactory response of Drosophila

    Institute of Scientific and Technical Information of China (English)

    PENG Yu; WANG YuFeng

    2009-01-01

    The endosymbiotic bacterium Wolbachia infects various insects and is primarily known for its ability to manipulate host reproduction.Recent investigations reveal that Wolbachia also affects the activity of somatic cells.We here demonstrated by trap method and T-maze that Wolbachia infection had signifi-cant impact on the olfactory response of Drosophila simulans.Wolbachia-infected flies took shorter time to enter the food trap and were more sensitive to odorant in T-maze than those uninfected controls,The time of olfactory response was relative to Wolbachia density in flies.Wolbachia density in 15-day-old flies that were caught in a shorter time (less than 60 min) by food trap was significantly higher than those taken in a longer time (more than 100 min).Quantitative RT-PCR showed that the transcript of an important odorant receptor gene or83b in flies with fast olfactory response was sig-nificantly more than those with slow olfactory response.These results suggest that Wolbachia might Increase olfactory response of flies by regulating the expression of olfaction-related genes in hosts.

  19. 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.

  20. Assessing olfactory performance in an Old World primate, Macaca nemestrina.

    Science.gov (United States)

    Hübener, F; Laska, M

    1998-06-15

    The present study demonstrates that an operant conditioning paradigm, originally designed for assessing olfactory performance in a small New World primate, the squirrel monkey, can successfully be adapted for use with a large Old World primate, the pigtail macaque. Using a task designed to simulate olfactory-guided foraging behavior, based on multiple discrimination of simultaneously presented odor stimuli, we could show that Macaca nemestrina is able to learn to discriminate between objects on the basis of odor cues. Moreover, they could readily transfer to new S+ and S- stimuli and could remember the significance of previously learned odor stimuli even after a 3-week break. Furthermore, we could show that this method is suitable for obtaining reliable measures of olfactory sensitivity. The few modifications of the original method employed here did not affect essential features such as the mode of stimulus presentation (odorized paper strips attached to manipulation objects) and the choice criterion (opening or rejecting the odorized manipulation objects), thus for the first time enabling valid interspecific comparisons of olfactory capabilities between a catarrhine and a platyrrhine primate species. Our results indicate that M. nemestrina and Saimiri sciureus are similar with regard to several measures of olfactory performance, such as speed of initial task acquisition and ability to master transfer tasks as well as their sensitivity to a food-related odorant. PMID:9761227

  1. Quantum Dot Distribution in the Olfactory Epithelium After Nasal Delivery

    Science.gov (United States)

    Garzotto, D.; De Marchis, S.

    2010-10-01

    Nanoparticles are used in a wide range of human applications from industrial to bio-medical fields. However, the unique characteristics of nanoparticles, such as the small size, large surface area per mass and high reactivity raises great concern on the adverse effects of these particles on ecological systems and human health. There are several pioneer studies reporting translocation of inhaled particulates to the brain through a potential neuronal uptake mediated by the olfactory nerve (1, 2, 3). However, no direct evidences have been presented up to now on the pathway followed by the nanoparticles from the nose to the brain. In addition to a neuronal pathway, nanoparticles could gain access to the central nervous system through extracellular pathways (perineuronal, perivascular and cerebrospinal fluid paths). In the present study we investigate the localization of intranasally delivered fluorescent nanoparticles in the olfactory epithelium. To this purpose we used quantum dots (QDs), a model of innovative fluorescent semiconductor nanocrystals commonly used in cell and animal biology (4). Intranasal treatments with QDs were performed acutely on adult CD1 mice. The olfactory epithelium was collected and analysed by confocal microscopy at different survival time after treatment. Data obtained indicate that the neuronal components of the olfactory epithelium are not preferentially involved in QDs uptake, thus suggesting nanoparticles can cross the olfactory epithelium through extracellular pathways.

  2. DESIGNERS’ KNOWLEDGE IN PLASTICS

    DEFF Research Database (Denmark)

    Eriksen, Kaare

    2013-01-01

    The Industrial designers’ knowledge in plastics materials and manufacturing principles of polymer products is very important for the innovative strength of the industry, according to a group of Danish plastics manufacturers, design students and practicing industrial designers. These three groups...... answered the first Danish national survey, PD13[1], investigating the importance of industrial designers’ knowledge in plastics and the collaboration between designers and the polymer industry. The plastics industry and the industrial designers collaborate well, but both groups frequently experience that...... designing plastic products....

  3. Journal of CHINA PLASTICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Journal of CHINA PLASTICS was authorized and approved by The State Committee of Science and Technology of China and The Bureau of News Press of China, and published by The China Plastics Processing Industry Association,Beijing Technology and Business University and The Institute of Plastics Processing and Application of Light Industry, distributed worldwide. Since its birth in 1987, CHINA PLASTICS has become a leading magazine in plastics industry in China, a national Chinese core journal and journal of Chinese scientific and technological article statistics. It is covered by CA.

  4. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

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  12. Challenges in plastics recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann;

    2015-01-01

    undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study was......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

  13. Glassy metallic plastics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports a class of bulk metallic glass including Ce-, LaCe-, CaLi-, Yb-, and Sr-based metallic glasses, which are regarded as glassy metallic plastics because they combine some unique properties of both plastics and metallic alloys. These glassy metallic plastics have very low glass transition temperature (Tg~25oC to 150oC) and low Young’s modulus (~20 GPa to 35 GPa). Similar to glassy plastics, these metallic plastics show excellent plastic-like deformability on macro-, micro- and even nano-scale in their supercooled liquid range and can be processed, such as elongated, compressed, bent, and imprinted at low temperatures, in hot water for instance. Under ambient conditions, they display such metallic properties as high thermal and electric conductivities and excellent mechanical properties and other unique properties. The metallic plastics have potential applications and are also a model system for studying issues in glass physics.

  14. Of mice and men: olfactory neuroblastoma among animals and humans.

    Science.gov (United States)

    Lubojemska, A; Borejko, M; Czapiewski, P; Dziadziuszko, R; Biernat, W

    2016-09-01

    Olfactory neuroblastoma (ONB) is a rare tumour of nasal cavity and paranasal sinuses that arises from the olfactory neuroepithelium and has unpredictable clinical course. As the sense of smell is phylogenetically one of the first senses and olfactory neuroepithelium is evolutionary conserved with striking similarities among different species, we performed an extensive analysis of the literature in order to evaluate the similarities and differences between animals and humans on the clinical, morphological, immunohistochemical, ultrastructural and molecular level. Our analysis revealed that ONB was reported mainly in mammals and showed striking similarities to human ONB. These observations provide rationale for introduction of therapy modalities used in humans into the veterinary medicine. Animal models of neuroblastoma should be considered for the preclinical studies evaluating novel therapies for ONB. PMID:25041470

  15. Effect of flumethrin on survival and olfactory learning in honeybees.

    Directory of Open Access Journals (Sweden)

    Ken Tan

    Full Text Available Flumethrin has been widely used as an acaricide for the control of Varroa mites in commercial honeybee keeping throughout the world for many years. Here we test the mortality of the Asian honeybee Apis cerana cerana after treatment with flumethrin. We also ask (1 how bees react to the odor of flumethrin, (2 whether its odor induces an innate avoidance response, (3 whether its taste transmits an aversive reinforcing component in olfactory learning, and (4 whether its odor or taste can be associated with reward in classical conditioning. Our results show that flumethrin has a negative effect on Apis ceranàs lifespan, induces an innate avoidance response, acts as a punishing reinforcer in olfactory learning, and interferes with the association of an appetitive conditioned stimulus. Furthermore flumethrin uptake within the colony reduces olfactory learning over an extended period of time.

  16. Methodological Considerations in Conducting an Olfactory fMRI Study

    Directory of Open Access Journals (Sweden)

    Faezeh Vedaei

    2013-01-01

    Full Text Available The sense of smell is a complex chemosensory processing in human and animals that allows them to connect with the environment as one of their chief sensory systems. In the field of functional brain imaging, many studies have focused on locating brain regions that are involved during olfactory processing. Despite wealth of literature about brain network in different olfactory tasks, there is a paucity of data regarding task design. Moreover, considering importance of olfactory tasks for patients with variety of neurological diseases, special contemplations should be addressed for patients. In this article, we review current olfaction tasks for behavioral studies and functional neuroimaging assessments, as well as technical principles regarding utilization of these tasks in functional magnetic resonance imaging studies.

  17. Functional MRI of the olfactory system in conscious dogs.

    Directory of Open Access Journals (Sweden)

    Hao Jia

    Full Text Available We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology.

  18. Phylogenic studies on the olfactory system in vertebrates.

    Science.gov (United States)

    Taniguchi, Kazuyuki; Taniguchi, Kazumi

    2014-06-01

    The olfactory receptor organs and their primary centers are classified into several types. The receptor organs are divided into fish-type olfactory epithelium (OE), mammal-type OE, middle chamber epithelium (MCE), lower chamber epithelium (LCE), recess epithelium, septal olfactory organ of Masera (SO), mammal-type vomeronasal organ (VNO) and snake-type VNO. The fish-type OE is observed in flatfish and lungfish, while the mammal-type OE is observed in amphibians, reptiles, birds and mammals. The MCE and LCE are unique to Xenopus and turtles, respectively. The recess epithelium is unique to lungfish. The SO is observed only in mammals. The mammal-type VNO is widely observed in amphibians, lizards and mammals, while the snake-type VNO is unique to snakes. The VNO itself is absent in turtles and birds. The mammal-type OE, MCE, LCE and recess epithelium seem to be descendants of the fish-type OE that is derived from the putative primitive OE. The VNO may be derived from the recess epithelium or fish-type OE and differentiate into the mammal-type VNO and snake-type VNO. The primary olfactory centers are divided into mammal-type main olfactory bulbs (MOB), fish-type MOB and mammal-type accessory olfactory bulbs (AOB). The mammal-type MOB first appears in amphibians and succeeds to reptiles, birds and mammals. The fish-type MOB, which is unique to fish, may be the ancestor of the mammal-type MOB. The mammal-type AOB is observed in amphibians, lizards, snakes and mammals and may be the remnant of the fish-type MOB. PMID:24531771

  19. Oxytocin facilitates the induction of long-term potentiation in the accessory olfactory bulb.

    Science.gov (United States)

    Fang, Long-Yun; Quan, Rong-Dan; Kaba, Hideto

    2008-06-20

    When female mice are mated, they form a memory to the pheromonal signal of their male partner. Several lines of evidence indicate that the neural changes underlying this memory occur in the accessory olfactory bulb (AOB) at the first stage of the vomeronasal system. The formation of this memory depends on the mating-induced release of noradrenaline in the AOB. In addition to noradrenaline, the neuropeptide oxytocin (OT) is also released within the central nervous system during mating. Because OT has been implicated in social memory and its receptors are expressed in the AOB, we hypothesized that OT might promote the strength of synaptic transmission from mitral to granule cells in the AOB. To test this hypothesis, we analyzed the lateral olfactory tract-evoked field potential that represents the granule cell response to mitral cell activation and its plasticity in parasagittal slices of the AOB. Of the 10-, 20-, 50-, and 100-Hz stimulations tested, the 100-Hz stimulation was optimal for inducing long-term potentiation (LTP). OT paired with 100-Hz stimulation that only produced short-term potentiation enhanced LTP induction in a dose-dependent manner. OT-paired LTP was blocked by both the selective OT antagonist desGly-NH(2),d(CH(2))(5)[Tyr(Me)(2),Thr(4)]-ornithine vasotocin and the N-methyl-d-aspartate (NMDA) receptor antagonist dl-2-amino-5-phosphonovaleric acid. These results indicate that OT can function as a gate to modulate the establishment of NMDA receptor-dependent LTP at the mitral-to-granule cell synapse in the AOB. PMID:18468792

  20. Menstrual effects on asymmetrical olfactory acuity.

    Science.gov (United States)

    Purdon, S E; Klein, S; Flor-Henry, P

    2001-09-01

    Gender specific discrepancies on psychometric examination are often interpreted to reflect static differences in cerebral hemisphere specialization, but dynamic alterations relating to circulating gonadal hormones may also be relevant after puberty. The often cited inference of a right hemisphere advantage in males and left hemisphere advantage in females derived from small but reliable differences on spatial tasks and verbal tasks, for example, may to some extent relate to gender-specific differences in circulating gonadal hormones. Performance fluctuations on other higher order cognitive tasks through the menstrual cycle tend to support a temporal association between alterations in cerebral laterality and hormone fluctuations. A potential left hemisphere advantage after menstruation when estrogen and progesterone levels are high in contrast to a right hemisphere advantage at menstruation when estrogen and progesterone levels are low has also received support from shifts in visual field perception. The present investigation continues this line of work by measurement of prospective changes in unirhinal olfactory acuity in the menstrual, ovulatory, and midluteal phases of the menstrual cycle in 11 healthy women who agreed to blood assays of estradiol and progesterone prior to completing a modified version of the Connecticut Chemosensory Perception Exam (CCPE). The CCPE detection of n-butanol showed a clear pattern of changes over the menstrual cycle marked by an asymmetry favoring the right nostril during menstruation when estradiol and progesterone levels were low, an asymmetry favoring the left nostril during ovulation when estradiol levels were high and progresterone levels were low, and an absence of asymmetry during the midluteal phase when estradiol levels decreased and progesterone levels increased. Preliminary correlation analyses revealed a potential competitive influence of estradiol and progesterone on this apparent shift in cerebral laterality. There is

  1. Morphogenetic Studies of the Drosophila DA1 Ventral Olfactory Projection Neuron

    OpenAIRE

    Shen, Hung-Chang; Wei, Jia-Yi; Chu, Sao-Yu; Chung, Pei-Chi; Hsu, Tsai-Chi; Yu, Hung-Hsiang

    2016-01-01

    In the Drosophila olfactory system, odorant information is sensed by olfactory sensory neurons and relayed from the primary olfactory center, the antennal lobe (AL), to higher olfactory centers via olfactory projection neurons (PNs). A major portion of the AL is constituted with dendrites of four groups of PNs, anterodorsal PNs (adPNs), lateral PNs (lPNs), lateroventral PNs (lvPNs) and ventral PNs (vPNs). Previous studies have been focused on the development and function of adPNs and lPNs, wh...

  2. Cross-adaptation to odor stimulation of olfactory receptor cells in the box turtle, Terrapene carolina.

    Science.gov (United States)

    Tonosaki, K

    1993-01-01

    Electrical recording from small twigs of olfactory nerve and electro-olfactogram (EOG) from olfactory epithelium in a turtle shows that olfactory receptors in the nose are responsive to various odors. I have used the effects of cross-adaptation to odor stimulation on the olfactory receptors to investigate the stimulus-specific components of these responses and to provide information about the responsiveness of cells. The results of the cross-adaptation experiments strongly support the hypothesis that different categories of receptor cells exist in the olfactory epithelium. PMID:8386588

  3. Olfactory dysfunction and neurotransmitter disturbance in olfactory bulb of transgenic mice expressing human A53T mutant α-synuclein.

    Directory of Open Access Journals (Sweden)

    Sufang Zhang

    Full Text Available Parkinson disease is a multi-system neurodegenerative disease characterized by both motor and non-motor symptoms. Hyposmia is one of the early non-motor symptoms occurring in more than 90% of Parkinson disease cases, which can precede motor symptoms even several years. Up to now, the relationship between hyposmia and Parkinson disease remains elusive. Lack of proper animal models of hyposmia restricts the investigation. In this study we assessed olfactory function in Prp-A53T-α-synuclein transgenic (αSynA53T mice which had been reported to show age-dependent motor impairments and intracytoplasmic inclusions. We also examined cholinergic and dopaminergic systems in olfactory bulb of αSynA53T mice by immunofluorescent staining, enzyme linked immunosorbent assay and western blot. We found that compared to wild type littermates, αSynA53T mice at 6 months or older displayed a deficit of odor discrimination and odor detection. No significant changes were found in olfactory memory and odor habituation. Furthermore compared to wildtype littermates, in olfactory bulb of αSynA53T mice at 10 months old we detected a marked decrease of cholinergic neurons in mitral cell layer and a decrease of acetylcholinesterase activity, while dopaminergic neurons were found increased in glomerular layer, accompanied with an increase of tyrosine hydroxylase protein. Our studies indicate that αSynA53T mice have olfactory dysfunction before motor deficits occur, and the cholinergic and dopaminergic disturbance might be responsible for the Parkinson disease-related olfactory dysfunction.

  4. Fos protein expression in olfactory-related brain areas after learning and after reactivation of a slowly acquired olfactory discrimination task in the rat

    OpenAIRE

    Roullet, Florence; Liénard, Fabienne; Datiche, Frédérique; Cattarelli, Martine

    2005-01-01

    Fos protein immunodetection was used to investigate the neuronal activation elicited in some olfactory-related areas after either learning of an olfactory discrimination task or its reactivation 10 d later. Trained rats (T) progressively acquired the association between one odor of a pair and water-reward in a four-arm maze. Two groups of pseudotrained rats were used: PO rats were not water restricted and were submitted to the olfactory stimuli in the maze without any reinforcement, whereas P...

  5. Olfactory bulb proteome dynamics during the progression of sporadic Alzheimer's disease: identification of common and distinct olfactory targets across Alzheimer-related co-pathologies

    OpenAIRE

    Zelaya, María Victoria; Pérez-Valderrama, Estela; de Morentin, Xabier Martínez; Tuñon, Teresa; Ferrer, Isidro; Luquin, María Rosario; Fernandez-Irigoyen, Joaquín; Santamaría, Enrique

    2015-01-01

    Olfactory dysfunction is present in up to 90% of Alzheimer's disease (AD) patients. Although deposition of hyperphosphorylated tau and β-amyloid substrates are present in olfactory areas, the molecular mechanisms associated with decreased smell function are not completely understood. We have applied mass spectrometry-based quantitative proteomics to probe additional molecular disturbances in postmortem olfactory bulbs (OB) dissected from AD cases respect to neurologically intact controls (n=2...

  6. Handbook of Plastic Welding

    DEFF Research Database (Denmark)

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve as a...

  7. Gamma Knife radiosurgery of olfactory groove meningiomas provides a method to preserve subjective olfactory function.

    Science.gov (United States)

    Gande, Abhiram; Kano, Hideyuki; Bowden, Gregory; Mousavi, Seyed H; Niranjan, Ajay; Flickinger, John C; Lunsford, L Dade

    2014-02-01

    Anosmia is a common outcome after resection of olfactory groove meningioma(s) (OGM) and for some patients represents a significant disability. To evaluate long term tumor control rates and preservation of subjective olfaction after Gamma Knife (GK) stereotactic radiosurgery (SRS) of OGM. We performed a retrospective chart review and telephone assessments of 41 patients who underwent GK SRS between 1987 and 2008. Clinical outcomes were stratified by full, partial or no subjective olfaction, whereas tumor control was assessed by changes in volume greater or lesser than 25%. The median clinical and imaging follow-up were 76 and 65 months, respectively. Prior to SRS, 19 (46%) patients had surgical resections and two (5%) had received fractionated radiation therapy. Twenty four patients (59%) reported a normal sense of smell, 12 (29%) reported a reduced sense of smell and five (12%) had complete anosmia. The median tumor volume was 8.5 cm(3) (range 0.6-56.1), the mean radiation dose at the tumor margin was 13 Gy (range 10-20) and the median estimated dose to the olfactory nerve was 5.1 Gy (range 1.1-18.1). At follow-up, 27 patients (66%) reported intact olfaction (three (7%) described return to a normal sense of smell), nine (22%) described partial anosmia, and five (12%) had complete anosmia. No patient reported deterioration in olfaction after SRS. Thirteen patients (32%) showed significant tumor regression, 26 (63%) had no further growth and two (5%) had progressed. The progression free tumor control rates were 97% at 1 year and 95% at 2, 10 and 20 years. Symptomatic adverse radiation effects occurred in three (7%) patients. Stereotactic radiosurgery provided both long term tumor control and preservation of olfaction. PMID:24398616

  8. Plasticized phenolphthalein polycarbonate

    Science.gov (United States)

    Harrison, E. S.

    1976-01-01

    Phenolphthalein polycarbonate was successfully plasticized with polychlorinated biphenyls (e.g., Aroclor 1231) or tricresyl phosphate and cast from tetrahydrofuran to give clear films without loss of fire resistance. At loadings of 20 to 30 percent plasticizer the Tg was lowered to approximately 100 C which would render phenolphthalein polycarbonate easily moldable. Although these materials had some mechanical integrity as shown by their film forming ability, the room temperature toughness of the plasticized polymer was not significantly improved over unmodified polymer.

  9. Development of plastic surgery

    OpenAIRE

    Pećanac Marija Đ.

    2015-01-01

    Introduction. Plastic surgery is a medical specialty dealing with corrections of defects, improvements in appearance and restoration of lost function. Ancient Times. The first recorded account of reconstructive plastic surgery was found in ancient Indian Sanskrit texts, which described reconstructive surgeries of the nose and ears. In ancient Greece and Rome, many medicine men performed simple plastic cosmetic surgeries to repair damaged parts of the body c...

  10. Plastic Pollution from Ships

    OpenAIRE

    ČULIN, Jelena; Bielić, Toni

    2016-01-01

    The environmental impact of shipping on marine environment includes discharge of garbage. Plastic litter is of particular concern due to abundance, resistance to degradation and detrimental effect on marine biota. According to recently published studies, a further research is required to assess human health risk. Monitoring data indicate that despite banning plastic disposal at sea, shipping is still a source of plastic pollution. Some of the measures to combat the problem are discussed.

  11. Spinocerebellar ataxia type 2 olfactory impairment shows a pattern similar to other major neurodegenerative diseases.

    Science.gov (United States)

    Velázquez-Pérez, Luis; Fernandez-Ruiz, Juan; Díaz, Rosalinda; González, Ruth Pérez; Ochoa, Nalia Canales; Cruz, Gilberto Sánchez; Mederos, Luis Enrique Almaguer; Góngora, Edilberto Martínez; Hudson, Robyn; Drucker-Colin, René

    2006-09-01

    Olfactory function is affected in different neurodegenerative diseases. Recently, it has been found that some hereditary ataxias are also associated with significant olfactory impairment. However, the initial findings did not examine the nature of the olfactory impairment associated with these ataxias. In the present article the effect of spinocerebellar ataxia type 2 (SCA2) on olfactory function was studied in 53 SCA2 patients and 53 healthy control subjects from Holguín, Cuba. Several tests were applied to evaluate olfactory threshold, description, identification and discrimination. The results show significant impairment in SCA2 patients on all olfactory measurements, and the pattern of olfactory deficits found suggests that they have much in common with those reported for other neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. PMID:16609806

  12. Synaptic Plasticity and Nociception

    Institute of Scientific and Technical Information of China (English)

    ChenJianguo

    2004-01-01

    Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

  13. Astrocytes: Orchestrating synaptic plasticity?

    Science.gov (United States)

    De Pittà, M; Brunel, N; Volterra, A

    2016-05-26

    Synaptic plasticity is the capacity of a preexisting connection between two neurons to change in strength as a function of neural activity. Because synaptic plasticity is the major candidate mechanism for learning and memory, the elucidation of its constituting mechanisms is of crucial importance in many aspects of normal and pathological brain function. In particular, a prominent aspect that remains debated is how the plasticity mechanisms, that encompass a broad spectrum of temporal and spatial scales, come to play together in a concerted fashion. Here we review and discuss evidence that pinpoints to a possible non-neuronal, glial candidate for such orchestration: the regulation of synaptic plasticity by astrocytes. PMID:25862587

  14. Plastics and health risks.

    Science.gov (United States)

    Halden, Rolf U

    2010-01-01

    By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics. PMID:20070188

  15. 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

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

    International Nuclear Information System (INIS)

    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

  17. Olfactory responses to attractants and repellents in tsetse

    NARCIS (Netherlands)

    Voskamp, KE; Everaarts, E; Den Otter, CJ

    1999-01-01

    The aims of this study were to investigate how antennal olfactory cells of tsetse (Diptera: Glossinidae) code odour quality and how they are able to discriminate between attractive and repellent odours. For Glossina pallidipes Austen, a survey is presented of the cells' responses to attractive (1-oc

  18. Human Adult Olfactory Bulb Neurogenesis? Novelty Is the Best Policy

    OpenAIRE

    Macklis, Jeffrey Daniel

    2012-01-01

    There is ongoing controversy as to whether the understanding of adult mammalian neurogenesis gained from rodent studies is applicable to humans. In this issue of Neuron, Bergmann et al. (2012) propose that adult human olfactory bulb neurogenesis with long-term neuronal survival is extremely limited.

  19. Cell migration in the developing rodent olfactory system.

    Science.gov (United States)

    Huilgol, Dhananjay; Tole, Shubha

    2016-07-01

    The components of the nervous system are assembled in development by the process of cell migration. Although the principles of cell migration are conserved throughout the brain, different subsystems may predominantly utilize specific migratory mechanisms, or may display unusual features during migration. Examining these subsystems offers not only the potential for insights into the development of the system, but may also help in understanding disorders arising from aberrant cell migration. The olfactory system is an ancient sensory circuit that is essential for the survival and reproduction of a species. The organization of this circuit displays many evolutionarily conserved features in vertebrates, including molecular mechanisms and complex migratory pathways. In this review, we describe the elaborate migrations that populate each component of the olfactory system in rodents and compare them with those described in the well-studied neocortex. Understanding how the components of the olfactory system are assembled will not only shed light on the etiology of olfactory and sexual disorders, but will also offer insights into how conserved migratory mechanisms may have shaped the evolution of the brain. PMID:26994098

  20. Multidimensional representation of odors in the human olfactory cortex.

    Science.gov (United States)

    Fournel, A; Ferdenzi, C; Sezille, C; Rouby, C; Bensafi, M

    2016-06-01

    What is known as an odor object is an integrated representation constructed from physical features, and perceptual attributes mainly mediated by the olfactory and trigeminal systems. The aim of the present study was to comprehend how this multidimensional representation is organized, by deciphering how similarities in the physical, olfactory and trigeminal perceptual spaces of odors are represented in the human brain. To achieve this aim, we combined psychophysics, functional MRI and multivariate representational similarity analysis. Participants were asked to smell odors diffused by an fMRI-compatible olfactometer and to rate each smell along olfactory dimensions (pleasantness, intensity, familiarity and edibility) and trigeminal dimensions (irritation, coolness, warmth and pain). An event-related design was implemented, presenting different odorants. Results revealed that (i) pairwise odorant similarities in anterior piriform cortex (PC) activity correlated with pairwise odorant similarities in chemical properties (P trigeminal perceptual properties (P trigeminal features is based on specific fine processing of similarities between odorous stimuli in a distributed manner in the olfactory system. Hum Brain Mapp 37:2161-2172, 2016. © 2016 Wiley Periodicals, Inc. PMID:26991044

  1. Assessing olfactory performance in a New World primate, Saimiri sciureus.

    Science.gov (United States)

    Laska, M; Hudson, R

    1993-01-01

    Using a task designed to simulate olfactory-guided foraging behavior, this study demonstrates for the first time that olfactory performance can be reliably assessed in squirrel monkeys. Small flip-top vials were fixed in random order to the arms of a climbing frame and equipped with odorized strips signalling either that they contained a peanut food reward (S+) or that they did not (S-), and three adult female monkeys were allowed 1 min to harvest as many baited nuts from this tree as possible. Given five 1-min trials per day, animals took between 15 and 25 days to reach the criterion of 80% correct choices, could readily transfer to new S+ or S- stimuli, and could remember the task even after a 1-month break. The precision and consistency of the monkeys' performance in tests of discrimination ability and sensitivity demonstrate the suitability of this paradigm for assessing olfactory function, and a first test of human subjects using the same cups and odorants showed that it may also be used to directly compare olfactory performance in human and nonhuman primates. PMID:8434074

  2. Olfactory Dysfunction in Narcolepsy with and without Cataplexy

    Czech Academy of Sciences Publication Activity Database

    Bušková, J.; Klaschka, Jan; Šonka, K.; Nevšímalová, S.

    2010-01-01

    Roč. 11, č. 6 (2010), s. 558-561. ISSN 1389-9457 Institutional research plan: CEZ:AV0Z10300504 Keywords : narcolepsy * cataplexy * narcolepsy without cataplexy * RBD * olfactory dysfunction Subject RIV: FH - Neurology Impact factor: 3.430, year: 2010

  3. Peripheral and central olfactory tuning in a moth.

    Science.gov (United States)

    Ong, Rose C; Stopfer, Mark

    2012-06-01

    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

  4. Neural correlates of taste perception in congenital olfactory impairment

    DEFF Research Database (Denmark)

    Gagnon, Léa; Vestergaard, Martin; Madsen, Kristoffer;

    2014-01-01

    Olfaction and gustation contribute both to the appreciation of food flavours. Although acquired loss of smell has profound consequences on the pleasure of eating, food habits and body weight, less is known about the impact of congenital olfactory impairment on gustatory processing. Here we examined...

  5. Optophysiological analysis of associational circuits in the olfactory cortex

    Directory of Open Access Journals (Sweden)

    Akari eHagiwara

    2012-04-01

    Full Text Available Primary olfactory cortical areas receive direct input from the olfactory bulb, but also have extensive associational connections that have been mainly studied with classical anatomical methods. Here, we shed light on the functional properties of associational connections in the anterior and posterior piriform cortex (aPC and pPC using optophysiological methods. We found that the aPC receives dense functional connections from the anterior olfactory nucleus (AON, a major hub in olfactory cortical circuits. The local recurrent connectivity within the aPC, long invoked in cortical autoassociative models, is sparse and weak. By contrast, the pPC receives negligible input from the AON, but has dense connections from the aPC as well as more local recurrent connections than the aPC. Finally, there are negligible functional connections from the pPC to aPC. Our study provides a circuit basis for a more sensory role for the aPC in odor processing and an associative role for the pPC.

  6. Penguins reduced olfactory receptor genes common to other waterbirds

    Science.gov (United States)

    Lu, Qin; Wang, Kai; Lei, Fumin; Yu, Dan; Zhao, Huabin

    2016-01-01

    The sense of smell, or olfaction, is fundamental in the life of animals. However, penguins (Aves: Sphenisciformes) possess relatively small olfactory bulbs compared with most other waterbirds such as Procellariiformes and Gaviiformes. To test whether penguins have a reduced reliance on olfaction, we analyzed the draft genome sequences of the two penguins, which diverged at the origin of the order Sphenisciformes; we also examined six closely related species with available genomes, and identified 29 one-to-one orthologous olfactory receptor genes (i.e. ORs) that are putatively functionally conserved and important across the eight birds. To survey the 29 one-to-one orthologous ORs in penguins and their relatives, we newly generated 34 sequences that are missing from the draft genomes. Through the analysis of totaling 378 OR sequences, we found that, of these functionally important ORs common to other waterbirds, penguins have a significantly greater percentage of OR pseudogenes than other waterbirds, suggesting a reduction of olfactory capability. The penguin-specific reduction of olfactory capability arose in the common ancestor of penguins between 23 and 60 Ma, which may have resulted from the aquatic specializations for underwater vision. Our study provides genetic evidence for a possible reduction of reliance on olfaction in penguins. PMID:27527385

  7. Altered Morphologies and Functions of the Olfactory Bulb and Hippocampus Induced by miR-30c.

    Science.gov (United States)

    Sun, Tingting; Li, Tianpeng; Davies, Henry; Li, Weiyun; Yang, Jing; Li, Shanshan; Ling, Shucai

    2016-01-01

    Adult neurogenesis is considered to contribute to a certain degree of plasticity for the brain. However, the effects of adult-born neurons on the brain are still largely unknown. Here, we specifically altered the expression of miR-30c in the subventricular zone (SVZ) and dentate gyrus (DG) by stereotaxic injection with their respective up- and down-regulated lentiviruses. Results showed an increased level of miR-30c enhanced adult neurogenesis by prompting cell-cycles of stem cells, whereas down-regulated miR-30c led to the opposite results. When these effects of miR-30c lasted for 3 months, we detected significant morphological changes in the olfactory bulb (OB) and lineage alteration in the hippocampus. Tests of olfactory sensitivity and associative and spatial memory showed that a certain amount of adult-born neurons are essential for the normal functions of the OB and hippocampus, but there also exist redundant newborn neurons that do not further improve the functioning of these areas. Our study revealed the interactions between miRNA, adult neurogenesis, brain morphology and function, and this provides a novel insight into understanding the role of newborn neurons in the adult brain. PMID:27242411

  8. Influence of Dietary Experience on the Induction of Preference of Adult Moths and Larvae for a New Olfactory Cue.

    Directory of Open Access Journals (Sweden)

    Christophe Petit

    Full Text Available In Lepidoptera, host plant selection is first conditioned by oviposition site preference of adult females followed by feeding site preference of larvae. Dietary experience to plant volatile cues can induce larval and adult host plant preference. We investigated how the parent's and self-experience induce host preference in adult females and larvae of three lepidopteran stem borer species with different host plant ranges, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and the monophagous Busseola nairobica, and whether this induction can be linked to a neurophysiological phenotypic plasticity. The three species were conditioned to artificial diet enriched with vanillin from the neonate larvae to the adult stage during two generations. Thereafter, two-choice tests on both larvae and adults using a Y-tube olfactometer and electrophysiological (electroantennography [EAG] recordings experiments on adults were carried out. In the polyphagous species, the induction of preference for a new olfactory cue (vanillin by females and 3rd instar larvae was determined by parents' and self-experiences, without any modification of the sensitivity of the females antennae. No preference induction was found in the oligophagous and monophagous species. Our results suggest that lepidopteran stem borers may acquire preferences for new olfactory cues from the larval to the adult stage as described by Hopkins' host selection principle (HHSP, neo-Hopkins' principle, and the concept of 'chemical legacy.'

  9. Altered morphologies and functions of the olfactory bulb and hippocampus induced by miR-30c

    Directory of Open Access Journals (Sweden)

    Tingting eSun

    2016-05-01

    Full Text Available Adult neurogenesis is considered to contribute to a certain degree of plasticity for the brain. However, the effects of adult-born neurons on the brain are still largely unknown. Here, we specifically altered the expression of miR-30c in the subventricular zone (SVZ and dentate gyrus (DG by stereotaxic injection with their respective up-and down-regulated lentiviruses. Results showed an increased level of miR-30c enhanced adult neurogenesis by prompting cell-cycles of stem cells, whereas down-regulated miR-30c led to the opposite results. When these effects of miR-30c lasted for three months, we detected significant morphological changes in the olfactory bulb (OB and lineage alteration in the hippocampus. Tests of olfactory sensitivity and associative and spatial memory showed that a certain amount of adult-born neurons are essential for the normal functions of the OB and hippocampus, but there also exist redundant newborn neurons that do not further improve the functioning of these areas. Our study revealed the interactions between miRNA, adult neurogenesis, brain morphology and function, and this provides a novel insight into understanding the role of newborn neurons in the adult brain.

  10. TRPM5-expressing microvillous cells in the main olfactory epithelium

    Directory of Open Access Journals (Sweden)

    Liman Emily R

    2008-11-01

    Full Text Available Abstract Background The main olfactory epithelium (MOE in the nasal cavity detects a variety of air borne molecules that provide information regarding the presence of food, predators and other relevant social and environmental factors. Within the epithelium are ciliated sensory neurons, supporting cells, basal cells and microvillous cells, each of which is distinct in morphology and function. Arguably, the least understood, are the microvillous cells, a population of cells that are small in number and whose function is not known. We previously found that in a mouse strain in which the TRPM5 promoter drives expression of the green fluorescent protein (GFP, a population of ciliated olfactory sensory neurons (OSNs, as well as a population of cells displaying microvilli-like structures is labeled. Here we examined the morphology and immunocytochemical properties of these microvillous-like cells using immunocytochemical methods. Results We show that the GFP-positive microvillous cells were morphologically diversified and scattered throughout the entire MOE. These cells immunoreacted to an antibody against TRPM5, confirming the expression of this ion channel in these cells. In addition, they showed a Ca2+-activated non-selective cation current in electrophysiological recordings. They did not immunoreact to antibodies that label cell markers and elements of the transduction pathways from olfactory sensory neurons and solitary chemosensory cells of the nasal cavity. Further, the TRPM5-expressing cells did not display axon-like processes and were not labeled with a neuronal marker nor did trigeminal peptidergic nerve fibers innervate these cells. Conclusion We provide morphological and immunocytochemical characterization of the TRPM5-expressing microvillous cells in the main olfactory epithelium. Our data demonstrate that these cells are non-neuronal and in terms of chemosensory transduction do not resemble the TRPM5-expressing olfactory sensory neurons

  11. Cigarette Smoke Delays Regeneration of the Olfactory Epithelium in Mice.

    Science.gov (United States)

    Ueha, Rumi; Ueha, Satoshi; Sakamoto, Takashi; Kanaya, Kaori; Suzukawa, Keigo; Nishijima, Hironobu; Kikuta, Shu; Kondo, Kenji; Matsushima, Kouji; Yamasoba, Tatsuya

    2016-08-01

    The olfactory system is a unique part of the mammalian nervous system due to its capacity for neurogenesis and the replacement of degenerating receptor neurons. Cigarette smoking is a major cause of olfactory dysfunction. However, the mechanisms by which cigarette smoke impairs the regenerative olfactory receptor neurons (ORNs) remain unclear. Here, we investigated the influence of cigarette smoke on ORN regeneration following methimazole-induced ORN injury. Administration of methimazole caused detachment of the olfactory epithelium from the basement membrane and induced olfactory dysfunction, thus enabling us to analyze the process of ORN regeneration. We found that intranasal administration of cigarette smoke solution (CSS) suppressed the recovery of ORNs and olfaction following ORN injury. Defective ORN recovery in CSS-treated mice was not associated with any change in the number of SOX2(+) ORN progenitor cells in the basal layer of the OE, but was associated with impaired recovery of GAP43(+) immature ORNs. In the nasal mucosa, mRNA expression levels of neurotrophic factors such as brain-derived neurotrophic factor, neurotrophin-3, neurotrophin-5, glial cell-derived neurotrophic factor, and insulin-like growth factor-1 (IGF-1) were increased following OE injury, whereas CSS administration decreased the ORN injury-induced IGF-1 expression. Administration of recombinant human IGF-1 prevented the CSS-induced suppression of ORN recovery following injury. These results suggest that CSS impairs regeneration of ORNs by suppressing the development of immature ORNs from ORN progenitors, at least partly by reducing IGF-1 in the nasal mucosa. PMID:27003941

  12. Olfactory subsystems in the honeybee: sensory supply and sex specificity.

    Science.gov (United States)

    Kropf, Jan; Kelber, Christina; Bieringer, Kathrin; Rössler, Wolfgang

    2014-09-01

    The antennae of honeybee (Apis mellifera) workers and drones differ in various aspects. One striking difference is the presence of Sensilla basiconica in (female) workers and their absence in (male) drones. We investigate the axonal projection patterns of olfactory receptor neurons (ORNs) housed in S. basiconica in honeybee workers by using selective anterograde labeling with fluorescent tracers and confocal-microscopy analysis of axonal projections in antennal lobe glomeruli. Axons of S. basiconica-associated ORNs preferentially projected into a specific glomerular cluster in the antennal lobe, namely the sensory input-tract three (T3) cluster. T3-associated glomeruli had previously been shown to be innervated by uniglomerular projection (output) neurons of the medial antennal lobe tract (mALT). As the number of T3 glomeruli is reduced in drones, we wished to determine whether this was associated with the reduction of glomeruli innervated by medial-tract projection neurons. We retrogradely traced mALT projection neurons in drones and counted the innervated glomeruli. The number of mALT-associated glomeruli was strongly reduced in drones compared with workers. The preferential projections of S. basiconica-associated ORNs in T3 glomeruli together with the reduction of mALT-associated glomeruli support the presence of a female (worker)-specific olfactory subsystem that is partly innervated by ORNs from S. basiconica and is associated with the T3 cluster of glomeruli and mALT projection neurons. We propose that this olfactory subsystem supports parallel olfactory processing related to worker-specific olfactory tasks such as the coding of colony odors, colony pheromones and/or odorants associated with foraging on floral resources. PMID:24817103

  13. Detecting plastics in seedcotton

    Science.gov (United States)

    To increase global market share and value the US cotton industry needs to supply cotton lint that is free of contamination. Removing plastic contamination first requires developing a means to detect plastics in seedcotton. This study was conducted to validate a custom Ion Mobility Spectrometer (IM...

  14. Halos of Plastic

    Institute of Scientific and Technical Information of China (English)

    Maya Reid

    2012-01-01

    The halos that span South Africa's coastline are anything but angelic. Fanning out around four major urban centers-Cape Town, Port Elizabeth, East London and Durban-they are made up of innumerable bits and pieces of plastic. As a form of pollution, their shelflife is unfathomable. Plastic is essentially chemically inactive. It's designed to never break down.

  15. Laser processing of plastics

    Science.gov (United States)

    Atanasov, Peter A.

    1995-03-01

    CO2-laser processing of plastics has been studied experimentally and theoretically. Welding of cylindrical parts made from polycarbonate and polypropylene, cutting of polymethyl-methacrylate plates, and drilling holes in polypropylene are presented as examples. A good coincidence between theoretical and experimental results in case of laser welding has been found. Some practical aspects of laser processing of plastics has been given.

  16. Analysis of glycoproteins produced by the associated gland in the olfactory organ of lungfish.

    Science.gov (United States)

    Nakamuta, Nobuaki; Nakamuta, Shoko; Taniguchi, Kazumi; Taniguchi, Kazuyuki

    2013-07-31

    The olfactory organ of African lungfish, Protopterus annectens, contains two distinct sensory epithelia: the lamellar olfactory epithelium and the recess epithelium. These epithelia correspond to the olfactory epithelium and the vomeronasal organ of tetrapods, respectively. In contrast to the lamellar olfactory epithelium, which has no associated gland, the recess epithelium is equipped with associated glands. Although the glandular cells and/or the supporting cells are generally presumed to secrete proteins involved in the function of olfactory sensory epithelia, the properties of these proteins in lungfish have not been evaluated to date. In this study, we investigated the associated glands in the olfactory organ of lungfish by transmission electron microscopy and found that the glandular cells contain numerous secretory granules and secrete them from the apical membrane. In addition, we analyzed the olfactory organ by lectin histochemistry using 16 biotinylated lectins. All lectins labeled the secretory granules in the glandular cells with different staining patterns from those of the supporting cells in the lamellar olfactory epithelium or in the recess epithelium. Furthermore, lectin blotting analysis showed that multiple bands were detected by the lectins which specifically labeled the glandular epithelium of the olfactory organ. These results indicate that the secretory products of the associated glands in the recess epithelium have different properties from those of the supporting cells in the olfactory sensory epithelia and contain multiple glycoproteins with different carbohydrate moieties. PMID:23428778

  17. American Society of Plastic Surgeons

    Science.gov (United States)

    ... doctor who is a member of the American Society of Plastic Surgeons (ASPS®), you can rest assured ... ASPS The Plastic Surgery Foundation Copyright © 2016 American Society of Plastic Surgeons | Privacy Policy | Sitemap | Terms and ...

  18. Hyperlipidemic diet causes loss of olfactory sensory neurons, reduces olfactory discrimination, and disrupts odor-reversal learning.

    Science.gov (United States)

    Thiebaud, Nicolas; Johnson, Melissa C; Butler, Jessica L; Bell, Genevieve A; Ferguson, Kassandra L; Fadool, Andrew R; Fadool, James C; Gale, Alana M; Gale, David S; Fadool, Debra A

    2014-05-14

    Currently, 65% of Americans are overweight, which leads to well-supported cardiovascular and cognitive declines. Little, however, is known concerning obesity's impact on sensory systems. Because olfaction is linked with ingestive behavior to guide food choice, its potential dysfunction during obesity could evoke a positive feedback loop to perpetuate poor ingestive behaviors. To determine the effect of chronic energy imbalance and reveal any structural or functional changes associated with obesity, we induced long-term, diet-induced obesity by challenging mice to high-fat diets: (1) in an obesity-prone (C57BL/6J) and obesity-resistant (Kv1.3(-/-)) line of mice, and compared this with (2) late-onset, genetic-induced obesity in MC4R(-/-) mice in which diabetes secondarily precipitates after disruption of the hypothalamic axis. We report marked loss of olfactory sensory neurons and their axonal projections after exposure to a fatty diet, with a concomitant reduction in electro-olfactogram amplitude. Loss of olfactory neurons and associated circuitry is linked to changes in neuronal proliferation and normal apoptotic cycles. Using a computer-controlled, liquid-based olfactometer, mice maintained on fatty diets learn reward-reinforced behaviors more slowly, have deficits in reversal learning demonstrating behavioral inflexibility, and exhibit reduced olfactory discrimination. When obese mice are removed from their high-fat diet to regain normal body weight and fasting glucose, olfactory dysfunctions are retained. We conclude that chronic energy imbalance therefore presents long-lasting structural and functional changes in the operation of the sensory system designed to encode external and internal chemical information and leads to altered olfactory- and reward-driven behaviors. PMID:24828650

  19. Correlation of olfactory dysfunction of different etiologies in MRI and comparison with subjective and objective olfactometry

    Energy Technology Data Exchange (ETDEWEB)

    Goektas, Oender [Department of Otolaryngology - Head and Neck Surgery, University of Berlin, Charite Campus Mitte, Smell and Taste Consultation Service, Berlin (Germany)], E-mail: oender.goektas@charite.de; Fleiner, Franca; Sedlmaier, Benedikt [Department of Otolaryngology - Head and Neck Surgery, University of Berlin, Charite Campus Mitte, Smell and Taste Consultation Service, Berlin (Germany); Bauknecht, Christian [Department of Radiology, University of Berlin, Charite Campus Mitte, Berlin (Germany)

    2009-09-15

    Background: The clinical diagnosis of olfactory dysfunction of different etiologies has been standardized by the German Working Group of Olfactology and Gustology, but there is no agreement about the most suitable imaging modality for diagnosing this disorder. Material and methods: A total of 24 patients (13 women, 11 men; mean age 52 years) with different types of olfactory dysfunction (anosmia, hyposmia) were examined by objective and subjective olfactometry and magnetic resonance imaging (MRI) of the olfactory bulb. Results: There was a positive correlation between objective olfactometry and volumetry of the olfactory bulb but no correlation between subjective olfactometry and MRI. Conclusion: MRI allows an evaluation of the olfactory bulb and appears to be superior to other modalities such as computed tomography (CT). Objective olfactometry remains the gold standard for reliable diagnosis of olfactory dysfunction.

  20. Correlation of olfactory dysfunction of different etiologies in MRI and comparison with subjective and objective olfactometry

    International Nuclear Information System (INIS)

    Background: The clinical diagnosis of olfactory dysfunction of different etiologies has been standardized by the German Working Group of Olfactology and Gustology, but there is no agreement about the most suitable imaging modality for diagnosing this disorder. Material and methods: A total of 24 patients (13 women, 11 men; mean age 52 years) with different types of olfactory dysfunction (anosmia, hyposmia) were examined by objective and subjective olfactometry and magnetic resonance imaging (MRI) of the olfactory bulb. Results: There was a positive correlation between objective olfactometry and volumetry of the olfactory bulb but no correlation between subjective olfactometry and MRI. Conclusion: MRI allows an evaluation of the olfactory bulb and appears to be superior to other modalities such as computed tomography (CT). Objective olfactometry remains the gold standard for reliable diagnosis of olfactory dysfunction.

  1. Oxytocin Enhances Social Recognition by Modulating Cortical Control of Early Olfactory Processing.

    Science.gov (United States)

    Oettl, Lars-Lennart; Ravi, Namasivayam; Schneider, Miriam; Scheller, Max F; Schneider, Peggy; Mitre, Mariela; da Silva Gouveia, Miriam; Froemke, Robert C; Chao, Moses V; Young, W Scott; Meyer-Lindenberg, Andreas; Grinevich, Valery; Shusterman, Roman; Kelsch, Wolfgang

    2016-05-01

    Oxytocin promotes social interactions and recognition of conspecifics that rely on olfaction in most species. The circuit mechanisms through which oxytocin modifies olfactory processing are incompletely understood. Here, we observed that optogenetically induced oxytocin release enhanced olfactory exploration and same-sex recognition of adult rats. Consistent with oxytocin's function in the anterior olfactory cortex, particularly in social cue processing, region-selective receptor deletion impaired social recognition but left odor discrimination and recognition intact outside a social context. Oxytocin transiently increased the drive of the anterior olfactory cortex projecting to olfactory bulb interneurons. Cortical top-down recruitment of interneurons dynamically enhanced the inhibitory input to olfactory bulb projection neurons and increased the signal-to-noise of their output. In summary, oxytocin generates states for optimized information extraction in an early cortical top-down network that is required for social interactions with potential implications for sensory processing deficits in autism spectrum disorders. PMID:27112498

  2. Early calcium increase triggers the formation of olfactory long-term memory in honeybees

    Directory of Open Access Journals (Sweden)

    Matsumoto Yukihisa

    2009-06-01

    Full Text Available Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+ plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward. Results By modulating the intracellular Ca2+ concentration ([Ca2+]i in the brain, we show that: (i blocking [Ca2+]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii conversely, increasing [Ca2+]i during single-trial conditioning triggers long-term memory formation; and finally, (iii as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca2+]i increase depends on de novo protein synthesis. Conclusion Altogether our data suggest that during olfactory conditioning Ca2+ is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca2+ therefore appears to act as a switch between short- and long-term storage of learned information.

  3. Age-Dependent Neurogenesis and Neuron Numbers within the Olfactory Bulb and Hippocampus of Homing Pigeons

    Science.gov (United States)

    Meskenaite, Virginia; Krackow, Sven; Lipp, Hans-Peter

    2016-01-01

    Many birds are supreme long-distance navigators that develop their navigational ability in the first months after fledgling but update the memorized environmental information needed for navigation also later in life. We studied the extent of juvenile and adult neurogenesis that could provide such age-related plasticity in brain regions known to mediate different mechanisms of pigeon homing: the olfactory bulb (OB), and the triangular area of the hippocampal formation (HP tr). Newly generated neurons (visualized by doublecortin, DCX) and mature neurons were counted stereologically in 35 pigeon brains ranging from 1 to 168 months of age. At the age of 1 month, both areas showed maximal proportions of DCX positive neurons, which rapidly declined during the first year of life. In the OB, the number of DCX-positive periglomerular neurons declined further over time, but the number of mature periglomerular cells appeared unchanged. In the hippocampus, the proportion of DCX-positive neurons showed a similar decline yet to a lesser extent. Remarkably, in the triangular area of the hippocampus, the oldest birds showed nearly twice the number of neurons as compared to young adult pigeons, suggesting that adult born neurons in these regions expanded the local circuitry even in aged birds. This increase might reflect navigational experience and, possibly, expanded spatial memory. On the other hand, the decrease of juvenile neurons in the aging OB without adding new circuitry might be related to the improved attachment to the loft characterizing adult and old pigeons. PMID:27445724

  4. Fish oil improves anxiety-like, depressive-like and cognitive behaviors in olfactory bulbectomised rats.

    Science.gov (United States)

    Pudell, Claudia; Vicente, Bianca A; Delattre, Ana M; Carabelli, Bruno; Mori, Marco A; Suchecki, Deborah; Machado, Ricardo B; Zanata, Sílvio M; Visentainer, Jesuí V; de Oliveira Santos Junior, Oscar; Lima, Marcelo M S; Ferraz, Anete C

    2014-01-01

    Depression is increasingly present in the population, and its pathophysiology and treatment have been investigated with several animal models, including olfactory bulbectomy (Obx). Fish oil (FO) supplementation during the prenatal and postnatal periods decreases depression-like and anxiety-like behaviors. The present study evaluated the effect of FO supplementation on Obx-induced depressive-like behavior and cognitive impairment. Female rats received supplementation with FO during habituation, mating, gestation, and lactation, and their pups were subjected to Obx in adulthood; after the recovery period, the adult offspring were subjected to behavioral tests, and the hippocampal levels of brain-derived neurotrophic factor (BDNF), serotonin (5-HT) and the metabolite 5-hydroxyindoleacetic (5-HIAA) were determined. Obx led to increased anxiety-like and depressive-like behaviors, and impairment in the object location task. All behavioral changes were reversed by FO supplementation. Obx caused reductions in the levels of hippocampal BDNF and 5-HT, whereas FO supplementation restored these levels to normal values. In control rats, FO increased the hippocampal level of 5-HT and reduced that of 5-HIAA, indicating low 5-HT metabolism in this brain region. The present results indicate that FO supplementation during critical periods of brain development attenuated anxiety-like and depressive-like behaviors and cognitive dysfunction induced by Obx. These results may be explained by increased levels of hippocampal BDNF and 5-HT, two major regulators of neuronal survival and long-term plasticity in this brain structure. PMID:24191918

  5. A Plastic Menagerie

    Science.gov (United States)

    Hadley, Mary Jane

    2010-01-01

    Bobble heads had become quite popular, depicting all sorts of sports figures, animals, and even presidents. In this article, the author describes how her fourth graders made bobble head sculptures out of empty plastic drink bottles. (Contains 1 online resource.)

  6. Dreaming in plastic

    Science.gov (United States)

    Korzhov, Marianna; Andelman, David; Shikler, Rafi

    2008-07-01

    Plastic is one of the most versatile materials available. It is cheap, flexible and easy to process, and as a result it is all around us - from our computer keyboards to the soles of our shoes. One of its most common applications is as an insulating coating for electric wires; indeed, plastic is well known for its insulating characteristics. It came as something of a surprise, therefore, when in the late 1970s a new generation of plastics was discovered that displayed exactly the opposite behaviour - the ability to conduct electricity. In fact, plastics can be made with a whole range of conductivities - there are polymer materials that behave like semiconductors and there are those that can conduct as well as metals. This discovery sparked a revolution in the electronics community, and three decades of research effort is now yielding a range of stunning new applications for this ubiquitous material.

  7. Enhanced Olfactory Sensory Perception of Threat in Anxiety: An Event-Related fMRI Study

    OpenAIRE

    Krusemark, Elizabeth A.; Li, Wen

    2012-01-01

    The current conceptualization of threat processing in anxiety emphasizes emotional hyper-reactivity, which mediates various debilitating symptoms and derangements in anxiety disorders. Here, we investigated olfactory sensory perception of threat as an alternative causal mechanism of anxiety. Combining an event-related functional magnetic resonance imaging paradigm with an olfactory discrimination task, we examined how anxiety modulates basic perception of olfactory threats at behavioral and n...

  8. Histological and Lectin Histochemical Studies on the Olfactory and Respiratory Mucosae of the Sheep

    OpenAIRE

    Ibrahim, Dalia; NAKAMUTA, Nobuaki; TANIGUCHI, Kazumi; Yamamoto, Yoshio; TANIGUCHI, Kazuyuki

    2013-01-01

    ABSTRACT The olfactory and respiratory mucosae of the Corriedale sheep were examined using lectin histochemistry in order to clarify the histochemical and glycohistochemical differences between these two tissues. The olfactory epithelium was stained with 13 lectins out of 21 lectins examined, while the respiratory epithelium was positive to 16 lectins. The free border of both of the olfactory and respiratory epithelia was stained with 12 lectins: Wheat germ agglutinin (WGA), succinylated-whea...

  9. One nose, one brain: contribution of the main and accessory olfactory system to chemosensation

    OpenAIRE

    Mucignat-Caretta, Carla; Redaelli, Marco; Caretta, Antonio

    2012-01-01

    The accessory olfactory system is present in most tetrapods. It is involved in the perception of chemical stimuli, being implicated also in the detection of pheromones. However, it is sensitive also to some common odorant molecules, which have no clear implication in intraspecific chemical communication. The accessory olfactory system may complement the main olfactory system and may contribute different perceptual features to the construction of a unitary representation, which merges the diff...

  10. Dilation of the olfactory bulb cavity concurrent with hydrocephalus in four small breed dogs

    OpenAIRE

    Kim, Jung-Hyun; Jeon, Hyo-Won; Woo, Eung-Je; Park, Hee-Myung

    2009-01-01

    Four small breed dogs were admitted with seizures. Magnetic resonance imaging (MRI) of the brain revealed dilation of the olfactory bulb cavity as well as enlargement of the lateral ventricles. These findings demonstrate that dilation of the olfactory bulb cavity can occur concurrent with hydrocephalus. This is the first description of the clinical and MRI features of dilation of the olfactory bulb cavity concurrent with hydrocephalus in dogs.

  11. Transplant connectivity in the rat olfactory bulb traced with DiI

    International Nuclear Information System (INIS)

    Tritiated thymidine pre-labelled presumptive olfactory bulbs (E15-17) were homo-topically transplanted in unilaterally bulbectomized neonatal rats (P3-5). At the time of transplantation a crystal of carbocyanine dye (DiI) was inserted into the center of the donor tissue. The results of in vivo DiI application demonstrated reestablished connections between the transplanted olfactory bulb and the higher olfactory centers of the host.. (authors)

  12. Parallel processing in the honeybee olfactory pathway: structure, function, and evolution

    OpenAIRE

    Rössler, Wolfgang; Brill, Martin F.

    2016-01-01

    Animals face highly complex and dynamic olfactory stimuli in their natural environments, which require fast and reliable olfactory processing. Parallel processing is a common principle of sensory systems supporting this task, for example in visual and auditory systems, but its role in olfaction remained unclear. Studies in the honeybee focused on a dual olfactory pathway. Two sets of projection neurons connect glomeruli in two antennal-lobe hemilobes via lateral and medial tracts in opposite ...

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

    Directory of Open Access Journals (Sweden)

    Adrien Molinas

    Full Text Available BACKGROUND: 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. PRINCIPAL FINDINGS: 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. CONCLUSIONS: 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

  14. Proliferative and Transcriptional Identity of Distinct Classes of Neural Precursors in the Mammalian Olfactory Epithelium

    OpenAIRE

    Tucker, Eric S.; Lehtinen, Maria Kristiina; Maynard, Tom; Zirlinger, Mariela; Dulac, Catherine; Rawson, Nancy; Pevny, Larysa; LaMantia, Anthony-Samuel

    2010-01-01

    Neural precursors in the developing olfactory epithelium (OE) give rise to three major neuronal classes – olfactory receptor (ORNs), vomeronasal (VRNs) and gonadotropin releasing hormone (GnRH) neurons. Nevertheless, the molecular and proliferative identities of these precursors are largely unknown. We characterized two precursor classes in the olfactory epithelium (OE) shortly after it becomes a distinct tissue at midgestation in the mouse: slowly dividing self-renewing precursors that expre...

  15. Mechanisms of constitutive and ATP-evoked ATP release in neonatal mouse olfactory epithelium

    OpenAIRE

    Hayoz Sébastien; Jia Cuihong; Hegg CC

    2012-01-01

    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...

  16. A dendrodendritic reciprocal synapse provides a recurrent excitatory connection in the olfactory bulb

    OpenAIRE

    Didier, Anne; Carleton, Alan; Jan G Bjaalie; Vincent, Jean-Didier; Ottersen, Ole Petter; Storm-Mathisen, Jon; Lledo, Pierre-Marie

    2001-01-01

    Neuronal synchronization in the olfactory bulb has been proposed to arise from a diffuse action of glutamate released from mitral cells (MC, olfactory bulb relay neurons). According to this hypothesis, glutamate spills over from dendrodendritic synapses formed between MC and granule cells (GC, olfactory bulb interneurons) to activate neighboring MC. The excitation of MC is balanced by a strong inhibition from GC. Here we show that MC excitation is caused by glutama...

  17. Detection of Volatile Indicators of Illicit Substances by the Olfactory Receptors of Drosophila melanogaster

    OpenAIRE

    Marshall, Brenton; Coral G Warr; de Bruyne, Marien

    2010-01-01

    Insects can detect a large range of odors with a numerically simple olfactory system that delivers high sensitivity and accurate discrimination. Therefore, insect olfactory receptors hold great promise as biosensors for detection of volatile organic chemicals in a range of applications. The array of olfactory receptor neurons of Drosophila melanogaster is rapidly becoming the best-characterized natural nose. We have investigated the suitability of Drosophila receptors as detectors for volatil...

  18. [Specific anosmia as a principle of olfactory perception].

    Science.gov (United States)

    Croy, I; Olgun, S; Mueller, L; Schmidt, A; Muench, M; Gisselmann, G; Hatt, H; Hummel, T

    2016-05-01

    Specific anosmia, the inability to perceive a specific odor, while olfactory perception is otherwise intact, is known as a rather seldom phenomenon. By testing the prevalence of specific anosmia to 20 different odors in a sample of 1600 people, we were able to estimate the general prevalence of anosmia. This revealed that specific anosmia is not rare at all. In contrast, the general likelihood for specific anosmia approaches 1. In addition, specific anosmia can be very well reversed by "smell training" during the course of 3 months. To summarize, specific anosmia seems to be a rule, not an exception, of olfactory sensation. The lack of perception of certain odors may constitute a flexible peripheral filter mechanism, which can be adapted by exposure to odors. PMID:26879880

  19. Olfactory neural tumours - the role of external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Slevin, N.J.; Irwin, C.J.R.; Banerjee, S.S.; Path, F.R.C.; Gupta, N.K.; Farrington, W.T. [Christie Hospital and Holt Radium Inst., Manchester (United Kingdom)

    1996-11-01

    Olfactory neuroblastoma is an uncommon tumour arising in the nasal cavity or paranasal sinuses. We report the management of nine cases treated with external beam radiotherapy subsequent to surgery, either attempted definitive removal or biopsy only. Recent refinements in pathological evaluation of these tumours are discussed. Seven cases were deemed classical olfactory neuroblastoma whilst two were classified as neuroendocrine carcinoma. The clinical features, radiotherapy technique and variable natural history are presented. Seven of eight patients treated radically were controlled locally, with a minimum follow-up of two years. Three patients developed cervical lymph node disease and three patients died of systemic metastatic disease. Suggestions are made as to which patients should have en-bloc resection rather than definitive radiotherapy. (author).

  20. Olfactory neural tumours - the role of external beam radiotherapy

    International Nuclear Information System (INIS)

    Olfactory neuroblastoma is an uncommon tumour arising in the nasal cavity or paranasal sinuses. We report the management of nine cases treated with external beam radiotherapy subsequent to surgery, either attempted definitive removal or biopsy only. Recent refinements in pathological evaluation of these tumours are discussed. Seven cases were deemed classical olfactory neuroblastoma whilst two were classified as neuroendocrine carcinoma. The clinical features, radiotherapy technique and variable natural history are presented. Seven of eight patients treated radically were controlled locally, with a minimum follow-up of two years. Three patients developed cervical lymph node disease and three patients died of systemic metastatic disease. Suggestions are made as to which patients should have en-bloc resection rather than definitive radiotherapy. (author)

  1. 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 (Peter Borowski, University of British Columbia, Canada; Juergen Reidl, University of Heidelberg, Germany; Jens Starke, Technical University of Denmark, Denmark; Martin Zapotocky, Max Planck Institute for Physics of Complex Systems, Germany; Markus Eiswirth, Fritz-Haber Institut, Germany; Anke...

  2. Broadcasting of cortical activity to the olfactory bulb.

    Science.gov (United States)

    Boyd, Alison M; Kato, Hiroyuki K; Komiyama, Takaki; Isaacson, Jeffry S

    2015-02-24

    Odor representations are initially formed in the olfactory bulb, which contains a topographic glomerular map of odor molecular features. The bulb transmits sensory information directly to piriform cortex, where it is encoded by distributed ensembles of pyramidal cells without spatial order. Intriguingly, piriform cortex pyramidal cells project back to the bulb, but the information contained in this feedback projection is unknown. Here, we use imaging in awake mice to directly monitor activity in the presynaptic boutons of cortical feedback fibers. We show that the cortex provides the bulb with a rich array of information for any individual odor and that cortical feedback is dependent on brain state. In contrast to the stereotyped, spatial arrangement of olfactory bulb glomeruli, cortical inputs tuned to different odors commingle and indiscriminately target individual glomerular channels. Thus, the cortex modulates early odor representations by broadcasting sensory information diffusely onto spatially ordered bulbar circuits. PMID:25704808

  3. Automated analyses of innate olfactory behaviors in rodents.

    Science.gov (United States)

    Qiu, Qiang; Scott, Aaron; Scheerer, Hayley; Sapkota, Nirjal; Lee, Daniel K; Ma, Limei; Yu, C Ron

    2014-01-01

    Olfaction based behavioral experiments are important for the investigation of sensory coding, perception, decision making and memory formation. The predominant experimental paradigms employ forced choice operant assays, which require associative learning and reinforced training. Animal performance in these assays not only reflects odor perception but also the confidence in decision making and memory. In this study, we describe a versatile and automated setup, "Poking-Registered Olfactory Behavior Evaluation System" (PROBES), which can be adapted to perform multiple olfactory assays. In addition to forced choice assays, we employ this system to examine animal's innate ability for odor detection, discrimination and preference without elaborate training procedures. These assays provide quantitative measurements of odor discrimination and robust readouts of odor preference. Using PROBES, we find odor detection thresholds are at lower concentrations in naïve animals than those determined by forced choice assays. PROBES-based automated assays provide an efficient way of analyzing innate odor-triggered behaviors. PMID:24699673

  4. Automated analyses of innate olfactory behaviors in rodents.

    Directory of Open Access Journals (Sweden)

    Qiang Qiu

    Full Text Available Olfaction based behavioral experiments are important for the investigation of sensory coding, perception, decision making and memory formation. The predominant experimental paradigms employ forced choice operant assays, which require associative learning and reinforced training. Animal performance in these assays not only reflects odor perception but also the confidence in decision making and memory. In this study, we describe a versatile and automated setup, "Poking-Registered Olfactory Behavior Evaluation System" (PROBES, which can be adapted to perform multiple olfactory assays. In addition to forced choice assays, we employ this system to examine animal's innate ability for odor detection, discrimination and preference without elaborate training procedures. These assays provide quantitative measurements of odor discrimination and robust readouts of odor preference. Using PROBES, we find odor detection thresholds are at lower concentrations in naïve animals than those determined by forced choice assays. PROBES-based automated assays provide an efficient way of analyzing innate odor-triggered behaviors.

  5. True navigation in migrating gulls requires intact olfactory nerves

    DEFF Research Database (Denmark)

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna;

    2015-01-01

    debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to <5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km......) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch...... of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances....

  6. Selective gene expression by postnatal electroporation during olfactory interneuron neurogenesis.

    Directory of Open Access Journals (Sweden)

    Alexander T Chesler

    Full Text Available Neurogenesis persists in the olfactory system throughout life. The mechanisms of how new neurons are generated, how they integrate into circuits, and their role in coding remain mysteries. Here we report a technique that will greatly facilitate research into these questions. We found that electroporation can be used to robustly and selectively label progenitors in the Subventicular Zone. The approach was performed postnatally, without surgery, and with near 100% success rates. Labeling was found in all classes of interneurons in the olfactory bulb, persisted to adulthood and had no adverse effects. The broad utility of electroporation was demonstrated by encoding a calcium sensor and markers of intracellular organelles. The approach was found to be effective in wildtype and transgenic mice as well as rats. Given its versatility, robustness, and both time and cost effectiveness, this method offers a powerful new way to use genetic manipulation to understand adult neurogenesis.

  7. Synaptic plasticity and phosphorylation

    OpenAIRE

    Lee, Hey-Kyoung

    2006-01-01

    A number of neuronal functions, including synaptic plasticity, depend on proper regulation of synaptic proteins, many of which can be rapidly regulated by phosphorylation. Neuronal activity controls the function of these synaptic proteins by exquisitely regulating the balance of various protein kinase and protein phosphatase activity. Recent understanding of synaptic plasticity mechanisms underscores important roles that these synaptic phosphoproteins play in regulating both pre- and post-syn...

  8. Extruded Plastic Scintillation Detectors

    CERN Document Server

    Pla-Dalmau, A; Mellott, K L; Pla-Dalmau, Anna; Bross, Alan D.; Mellott, Kerry L.

    1999-01-01

    As a way to lower the cost of plastic scintillation detectors, commercially available polystyrene pellets have been used in the production of scintillating materials that can be extruded into different profiles. The selection of raw materials is discussed. Two techniques to add wavelength shifting dopants to polystyrene pellets and to extrude plastic scintillating strips are described. Data on light yield and transmittance measurements are presented.

  9. Experimental evolution of olfactory memory in Drosophila melanogaster

    OpenAIRE

    Mery, Frederic; Pont, Juliette; Preat, Thomas; Kawecki, Tadeusz J.

    2007-01-01

    In order to address the nature of genetic variation in learning performance, we investigated the response to classical olfactory conditioning in "high-learning" Drosophila melanogaster lines previously subject to selection for the ability to learn an association between the flavor of an oviposition medium and bitter taste. In a T-maze choice test, the seven high-learning lines were better at avoiding an odor previously associated with aversive mechanical shock than were five unselected "low-l...

  10. Brain composition and olfactory learning in honey bees

    OpenAIRE

    Gronenberg, Wulfila; Couvillon, Margaret J

    2010-01-01

    Correlations between brain or brain component size and behavioral measures are frequently studied by comparing different animal species, which sometimes introduces variables that complicate interpretation in terms of brain function. Here, we have analyzed the brain composition of honey bees (Apis mellifera) that have been individually tested in an olfactory learning paradigm. We found that the total brain size correlated with the bees’ learning performance. Among different brain components, o...

  11. Testing olfactory foraging strategies in an Antarctic seabird assemblage

    OpenAIRE

    Nevitt, G A; Reid, K; Trathan, P.

    2004-01-01

    Procellariiform seabirds (petrels, albatrosses and shearwaters) forage over thousands of square kilometres for patchily distributed prey resources. While these birds are known for their large olfactory bulbs and excellent sense of smell, how they use odour cues to locate prey patches in the vast ocean is not well understood. Here, we investigate species-specific responses to 3-methyl pyrazine in a sub-Antarctic species assemblage near South Georgia Island (54degrees00' S, 36degrees00' W). Pyr...

  12. Insect olfactory coding and memory at multiple timescales

    OpenAIRE

    Gupta, Nitin; Stopfer, Mark

    2011-01-01

    Insects can learn, allowing them great flexibility for locating seasonal food sources and avoiding wily predators. Because insects are relatively simple and accessible to manipulation, they provide good experimental preparations for exploring mechanisms underlying sensory coding and memory. Here we review how the intertwining of memory with computation enables the coding, decoding, and storage of sensory experience at various stages of the insect olfactory system. Individual parts of this sys...

  13. Differential odor processing in two olfactory pathways in the honeybee

    OpenAIRE

    Nobuhiro Yamagata; Michael Schmuker; Paul Szyszka; Makoto Mizunami; Randolf Menzel

    2009-01-01

    An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN). Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons) of two types of PNs – lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentrat...

  14. Distinct neural mechanisms mediate olfactory memory formation at different timescales

    OpenAIRE

    McNamara, Ann Marie; Magidson, Phillip D.; Linster, Christiane; Donald A Wilson; Cleland, Thomas A.

    2008-01-01

    Habituation is one of the oldest forms of learning, broadly expressed across sensory systems and taxa. Here, we demonstrate that olfactory habituation induced at different timescales (comprising different odor exposure and intertrial interval durations) is mediated by different neural mechanisms. First, the persistence of habituation memory is greater when mice are habituated on longer timescales. Second, the specificity of the memory (degree of cross-habituation to similar stimuli) also depe...

  15. GSK-3/Shaggy regulates olfactory habituation in Drosophila

    OpenAIRE

    Wolf, Fred W; Eddison, Mark; Lee, Seonok; Cho, William; Heberlein, Ulrike

    2007-01-01

    Habituation is a universal form of nonassociative learning that results in the devaluation of sensory inputs that have little information content. Although habituation is found throughout nature and has been studied in many organisms, the underlying molecular mechanisms remain poorly understood. We performed a forward genetic screen in Drosophila to search for mutations that modified habituation of an olfactory-mediated locomotor startle response, and we isolated a mutation in the glycogen sy...

  16. Distinct molecular underpinnings of Drosophila olfactory trace conditioning

    OpenAIRE

    Shuai, Yichun; Hu, Ying; Qin, Hongtao; Campbell, Robert A. A.; Zhong, Yi

    2011-01-01

    Trace conditioning is valued as a simple experimental model to assess how the brain associates events that are discrete in time. Here, we adapted an olfactory trace conditioning procedure in Drosophila melanogaster by training fruit flies to avoid an odor that is followed by foot shock many seconds later. The molecular underpinnings of the learning are distinct from the well-characterized simultaneous conditioning, where odor and punishment temporally overlap. First, Rutabaga adenylyl cyclase...

  17. Humans can Discriminate more than one Trillion Olfactory Stimuli

    OpenAIRE

    Bushdid, C.; Magnasco, M. O.; Vosshall, L. B.; Keller, A.

    2014-01-01

    Humans can discriminate several million different colors and almost half a million different tones, but the number of discriminable olfactory stimuli remains unknown. The lay and scientific literature typically claims that humans can discriminate 10,000 odors, but this number has never been empirically validated. Here, we determined the resolution of the human sense of smell by testing the capacity of humans to discriminate odor mixtures with varying numbers of shared components. Based on the...

  18. Response of cattle grazing on pasture on olfactory stimuli

    OpenAIRE

    Fiebigerová, Kateřina

    2014-01-01

    This diploma thesis is focused on responses of cattle on olfactory stimuli. The investigation was conducted on Experimental Station for Fodder Production, Animal Nutrition and Dairy Science – Gut Grunschweige, Eiting, Germany, belonging to Munich Technican University. Animals were bred in farm conditions on pasture and there were observed 2 herds of Limousine cattle. The objective of this paper was to determine whether cattle respond to different smells in terms of motivation conflict between...

  19. Chemotopic Odorant Coding in a Mammalian Olfactory System

    OpenAIRE

    Johnson, Brett A.; Leon, Michael

    2007-01-01

    Systematic mapping studies involving 365 odorant chemicals have shown that glomerular responses in the rat olfactory bulb are organized spatially in patterns that are related to the chemistry of the odorant stimuli. This organization involves the spatial clustering of principal responses to numerous odorants that share key aspects of chemistry such as functional groups, hydrocarbon structural elements, and/or overall molecular properties related to water solubility. In several of the clusters...

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

    OpenAIRE

    Grimaud, Julien; Lledo, Pierre-Marie

    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 relations...

  1. Automated Analyses of Innate Olfactory Behaviors in Rodents

    OpenAIRE

    Qiu, Qiang; Scott, Aaron; Scheerer, Hayley; Sapkota, Nirjal; Lee, Daniel K.; Ma, Limei; Yu, C. Ron

    2014-01-01

    Olfaction based behavioral experiments are important for the investigation of sensory coding, perception, decision making and memory formation. The predominant experimental paradigms employ forced choice operant assays, which require associative learning and reinforced training. Animal performance in these assays not only reflects odor perception but also the confidence in decision making and memory. In this study, we describe a versatile and automated setup, “Poking-Registered Olfactory Beha...

  2. Method of expression of certain bacterial microflora mucosa olfactory area

    Science.gov (United States)

    Avrunin, Oleg G.; Nosova, Yana V.; Shushlyapina, Natalia O.; Surtel, Wojciech; Burlibay, Aron; Zhassandykyzy, Maral

    2015-12-01

    The article is devoted to the actual problem - the development of new express diagnostic methods, based on which a doctor-otolaryngologist can quickly and efficiently determine a violation of smell. The work is based on the methods of processing and analysis of medical images and signals. We have also identified informative indicators of endoscopic image of the olfactory region of the nasal mucosa of the upper course.

  3. The effect of smoking on the olfactory function.

    Science.gov (United States)

    Katotomichelakis, Michael; Balatsouras, Dimitrios; Tripsianis, Gregory; Davris, Spiros; Maroudias, Nikolaos; Danielides, Vassilios; Simopoulos, Constantinos

    2007-12-01

    Although smoking is a widely spread habit, its effect on olfaction has not been clearly established. The aim of this study was to investigate the effect of cigarette smoking on the olfactory function, using the "Sniffin' Sticks" test. Sixty-five smokers were studied, with a median period of smoking of 10 years (range: 1-45 years) and a median number of 15 cigarettes smoked per day (range: 5-20). Forty-nine non-smokers were used as controls. Olfactory function was evaluated using the "Sniffin' Sticks" test, which consists of odour threshold (OT), odour discrimination (OD) and odour identification (OI) and its overall results may be presented as a composite threshold-discrimination-identification (TDI) score. Multivariate linear and logistic regression analyses were performed. All OT, OD, OI and TDI scores were statistically significantly lower in smokers compared to non-smokers, even when controlled for gender and age. Low OT, OD, OI and TDI scores were more prevalent among smokers than non-smokers. Multivariate logistic regression analysis, adjusted for gender and age, revealed that smoking remained a strong independent risk factor for low OT, OD, OI and TDI scores. Among smokers, statistically significant negative relationships were found between pack-years and OT, OD, OI and TDI, controlling for age. In conclusion, smoking was found to be adversely associated with the olfactory ability in a dose-related manner. Smokers were found to be nearly six times as likely to evidence an olfactory deficit as non smokers, depending on the duration and the amount of cigarettes smoked. PMID:18085020

  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. PMID:26655822

  5. Development of plastic surgery

    Directory of Open Access Journals (Sweden)

    Pećanac Marija Đ.

    2015-01-01

    Full Text Available Introduction. Plastic surgery is a medical specialty dealing with corrections of defects, improvements in appearance and restoration of lost function. Ancient Times. The first recorded account of reconstructive plastic surgery was found in ancient Indian Sanskrit texts, which described reconstructive surgeries of the nose and ears. In ancient Greece and Rome, many medicine men performed simple plastic cosmetic surgeries to repair damaged parts of the body caused by war mutilation, punishment or humiliation. In the Middle Ages, the development of all medical braches, including plastic surgery was hindered. New age. The interest in surgical reconstruction of mutilated body parts was renewed in the XVIII century by a great number of enthusiastic and charismatic surgeons, who mastered surgical disciplines and became true artists that created new forms. Modern Era. In the XX century, plastic surgery developed as a modern branch in medicine including many types of reconstructive surgery, hand, head and neck surgery, microsurgery and replantation, treatment of burns and their sequelae, and esthetic surgery. Contemporary and future plastic surgery will continue to evolve and improve with regenerative medicine and tissue engineering resulting in a lot of benefits to be gained by patients in reconstruction after body trauma, oncology amputation, and for congenital disfigurement and dysfunction.

  6. Neuropeptide Y-like immunoreactive neurons in the human olfactory bulb.

    Science.gov (United States)

    Ohm, T G; Braak, E; Probst, A; Weindl, A

    1988-06-01

    Neuropeptide Y-like (NPY) immunoreactivity was localized in the adult human olfactory bulb by the unlabeled antibody enzyme (peroxidase anti-peroxidase; PAP) technique in vibratome sections. The majority of NPY-immunoreactive somata was localized in the white matter surrounding the anterior olfactory nucleus. Immunoreactive neurons were less numerous within the anterior olfactory nucleus and within the olfactory bulb layers. NPY-immunoreactive fibres were present in the white matter, the anterior olfactory nucleus, and in the olfactory bulb layers. Fibres within the white matter were generally aligned in a straight path parallel to the long axis of the olfactory bulb and tract. Fibres within the anterior olfactory nucleus showed no clear orientation and displayed numerous branching points. Coiled plexus of NPY-immunoreactive fibres were present in the glomerular layer of the olfactory bulb. Additional characteristics of the NPY-immunoreactive neurons were studied after decolouring the chromogen and restaining the sections with aldehydefuchsin to demonstrate the presence of lipofuscin granules and also with gallocyanin chrome alum to stain the Nissl substance. This analysis showed that the neurons belong to the class of non-pigmented nerve cells. PMID:3251589

  7. Olfactory deficits in Niemann-Pick type C1 (NPC1 disease.

    Directory of Open Access Journals (Sweden)

    Marina Hovakimyan

    Full Text Available BACKGROUND: Niemann-Pick type C disease (NPC is a rare autosomal recessive lipid storage disease characterized by progressive neurodegeneration. As only a few studies have been conducted on the impact of NPC on sensory systems, we used a mutant mouse model (NPC1(-/- to examine the effects of this disorder to morphologically distinct regions of the olfactory system, namely the olfactory epithelium (OE and olfactory bulb (OB. METHODOLOGY/PRINCIPAL FINDINGS: For structural and functional analysis immunohistochemistry, electron microscopy, western blotting, and electrophysiology have been applied. For histochemistry and western blotting, we used antibodies against a series of neuronal and glia marker proteins, as well as macrophage markers. NPC1(-/- animals present myelin-like lysosomal deposits in virtually all types of cells of the peripheral and central olfactory system. Especially supporting cells of the OE and central glia cells are affected, resulting in pronounced astrocytosis and microgliosis in the OB and other olfactory cortices. Up-regulation of Galectin-3, Cathepsin D and GFAP in the cortical layers of the OB underlines the critical role and location of the OB as a possible entrance gate for noxious substances. Unmyelinated olfactory afferents of the lamina propria seem less affected than ensheathing cells. Supporting the structural findings, electro-olfactometry of the olfactory mucosa suggests that NPC1(-/- animals exhibit olfactory and trigeminal deficits. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate a pronounced neurodegeneration and glia activation in the olfactory system of NPC1(-/-, which is accompanied by sensory deficits.

  8. Olfactory training induces changes in regional functional connectivity in patients with long-term smell loss

    Directory of Open Access Journals (Sweden)

    K. Kollndorfer

    2015-01-01

    The results of this study indicate that an olfactory training program can reorganize functional networks, although, initially, no differences in the spatial distribution of neural activation were observed.

  9. Olfactory Predictive Codes and Stimulus Templates in Piriform Cortex

    Science.gov (United States)

    Zelano, Christina; Mohanty, Aprajita; Gottfried, Jay A.

    2011-01-01

    Summary Neuroscientific models of sensory perception suggest that the brain utilizes predictive codes in advance of a stimulus encounter, enabling organisms to infer forthcoming sensory events. However, it is poorly understood how such mechanisms are implemented in the olfactory system. Combining high-resolution functional magnetic resonance imaging with multivariate (pattern-based) analyses, we examined the spatiotemporal evolution of odor perception in the human brain during an olfactory search task. Ensemble activity patterns in anterior piriform cortex (APC) and orbitofrontal cortex (OFC) reflected the attended odor target both before and after stimulus onset. In contrast, pre-stimulus ensemble representations of the odor target in posterior piriform cortex (PPC) gave way to post-stimulus representations of the odor itself. Critically, the robustness of target-related patterns in PPC predicted subsequent behavioral performance. Our findings directly show that the brain generates predictive templates or “search images” in PPC, with physical correspondence to odor-specific pattern representations, to augment olfactory perception. PMID:21982378

  10. Classification of odorants across layers in locust olfactory pathway.

    Science.gov (United States)

    Sanda, Pavel; Kee, Tiffany; Gupta, Nitin; Stopfer, Mark; Bazhenov, Maxim

    2016-05-01

    Olfactory processing takes place across multiple layers of neurons from the transduction of odorants in the periphery, to odor quality processing, learning, and decision making in higher olfactory structures. In insects, projection neurons (PNs) in the antennal lobe send odor information to the Kenyon cells (KCs) of the mushroom bodies and lateral horn neurons (LHNs). To examine the odor information content in different structures of the insect brain, antennal lobe, mushroom bodies and lateral horn, we designed a model of the olfactory network based on electrophysiological recordings made in vivo in the locust. We found that populations of all types (PNs, LHNs, and KCs) had lower odor classification error rates than individual cells of any given type. This improvement was quantitatively different from that observed using uniform populations of identical neurons compared with spatially structured population of neurons tuned to different odor features. This result, therefore, reflects an emergent network property. Odor classification improved with increasing stimulus duration: for similar odorants, KC and LHN ensembles reached optimal discrimination within the first 300-500 ms of the odor response. Performance improvement with time was much greater for a population of cells than for individual neurons. We conclude that, for PNs, LHNs, and KCs, ensemble responses are always much more informative than single-cell responses, despite the accumulation of noise along with odor information. PMID:26864765

  11. Minimally invasive resection of olfactory neuroblastoma by transnasal endoscopy.

    Science.gov (United States)

    Chang, Chin-Fang; Chiu, Sheng-Chang; Yeh, Shiou-Yu; Chen, Mu-Kuan; Wen, Yung-Sung

    2015-08-01

    Olfactory neuroblastoma is rare. We conducted a retrospective study to review our experience with minimally invasive resection of olfactory neuroblastomas via a transnasal endoscopic technique, including an analysis of surgical outcomes. Our series included 5 patients-3 men and 2 women, aged 29 to 75 years (mean: 48). Surgical outcomes were evaluated on the basis of each patient's preoperative Dulguerov classification and postoperative evaluation on computed tomography and magnetic resonance imaging. One patient was treated with surgery alone, 3 with surgery plus radiotherapy, and 1 with surgery, radiotherapy, and chemotherapy. During follow-up of 18 to 115 months, all 5 patients remained alive and disease-free. We found that endoscopic resection of olfactory neuroblastoma is a feasible and effective procedure, even in patients with more aggressive stages of disease. We also believe that the Dulguerov classification is more useful than other classifications for clinical management and surgical planning. Long-term follow-up is necessary to look for late recurrence. PMID:26322455

  12. Transmission of olfactory information for tele-medicine

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.; Kouzes, R.T.; Kangas, L.J.; Hashem, S.

    1995-01-01

    While the inclusion of visual, aural, and tactile senses into virtual reality systems is widespread, the sense of smell has been largely ignored. We have developed a chemical vapor sensing system for the automated identification of chemical vapors (smells). Our prototype chemical vapor sensing system is composed of an array of tin-oxide vapor sensors coupled to an artificial neural net-work. The artificial neural network is used in the recognition of different smells and is constructed as a standard multilayer feed-forward network trained with the backpropagation algorithm. When a chemical sensor array is combined with an automated pattern identifier, it is often referred to as an electronic or artificial nose. Applications of electronic noses include monitoring food and beverage odors, automated flavor control, analyzing fuel mixtures, and quantifying individual components in gas mixtures. Our prototype electronic nose has been used to identify odors from common household chemicals. An electronic nose will potentially be a key component in an olfactory input to a telepresent virtual reality system. The identified odor would be electronically transmitted from the electronic nose at one site to an odor generation system at another site. This combination would function as a mechanism for transmitting olfactory information for telepresence. This would have direct applicability in the area of telemedicine since the sense of smell is an important sense to the physician and surgeon. In this paper, our chemical sensing system (electronic nose) is presented along with a proposed method for regenerating the transmitted olfactory information.

  13. Molecular Cooperativity Governs Diverse and Monoallelic Olfactory Receptor Expression

    Science.gov (United States)

    Xing, Jianhua; Tian, Xiaojun; Zhang, Hang; Sannerud, Jens

    Multiple-objective optimization is common in biological systems. In the mammalian olfactory system, each sensory neuron stochastically expresses only one out of up to thousands of olfactory receptor (OR) gene alleles; at organism level the types of expressed ORs need to be maximized. The molecular mechanism of this Nobel-Prize winning puzzle remains unresolved after decades of extensive studies. Existing models focus only on monoallele activation, and cannot explain recent observations in mutants, especially the reduced global diversity of expressed ORs in G9a/GLP knockouts. In this work we integrated existing information on OR expression, and proposed an evolutionarily optimized three-layer regulation mechanism, which includes zonal segregation, epigenetic and enhancer competition coupled to a negative feedback loop. This model not only recapitulates monoallelic OR expression, but also elucidates how the olfactory system maximizes and maintains the diversity of OR expression. The model is validated by several experimental results, and particularly underscores cooperativity and synergy as a general design principle of multi-objective optimization in biology. The work is supported by the NIGMS/DMS Mathematical Biology program.

  14. Olfactory bulb volume predicts therapeutic outcome in major depression disorder.

    Science.gov (United States)

    Negoias, Simona; Hummel, Thomas; Symmank, Anja; Schellong, Julia; Joraschky, Peter; Croy, Ilona

    2016-06-01

    The volume of the olfactory bulb (OB) is strongly reduced in patients with major depressive disorder (MDD) and this group exhibits markedly decreased olfactory function. It has been suggested that olfactory input is important for maintaining balance in limbic neurocircuits. The aim of our study was to investigate whether reduced OB volume is associated with response to therapy in MDD. Twenty-four inpatients (all women, age 21-49 years, mean 38 ± 10 years SD) with MDD and 36 healthy controls (all women, age 20-52 years, mean 36 ± 10 years SD) underwent structural MRI. OB volume was compared between responders (N = 13) and non-responders (N = 11) to psychotherapy. Retest of OB volume was performed about 6 months after the end of therapy in nine of the patients. Therapy responders exhibited no significant difference in OB volume compared to healthy controls. However, average OB volume of non-responders was 23 % smaller compared to responders (p = .0011). Furthermore, OB volume was correlated with the change of depression severity (r = .46, p = .024). Volume of the OB did not change in the course of therapy. OB volume may be a biological vulnerability factor for the occurrence and/or maintenance of depression, at least in women. PMID:25977168

  15. Function of attention in learning process in the olfactory bulb

    Institute of Scientific and Technical Information of China (English)

    马宝生; 王顺鹏; 李岩; 冯春华; 郭爱克

    2003-01-01

    It has been suggested that in the olfactory bulb, odor information is processed through parallel channels and learning depends on the cognitive environment. The synapse's spike effective time is defined as the effective time for a spike from pre-synapse to post-synapse, which varies with the type of synapse. A learning model of the olfactory bulb was constructed for synapses with varying spike effective times. The simulation results showed that such a model can realize the multi-channel processing of information in the bulb. Furthermore, the effect of the cognitive environment on the learning process was also studied. Different feedback frequencies were used to express different attention states. Considering the information's multi-channel processing requirement for learning, a learning rule considering both spike timing and average spike frequency is proposed. Simulation results showed that habituation and anti-habituation of an odor in the olfactory bulb might be the result of learning guided by a common local learning rule but at different attention states.

  16. Olfactory coding in five moth species from two families.

    Science.gov (United States)

    Bisch-Knaden, Sonja; Carlsson, Mikael A; Sugimoto, Yuki; Schubert, Marco; Mißbach, Christine; Sachse, Silke; Hansson, Bill S

    2012-05-01

    The aim of the present study was to determine what impact phylogeny and life history might have on the coding of odours in the brain. Using three species of hawk moths (Sphingidae) and two species of owlet moths (Noctuidae), we visualized neural activity patterns in the antennal lobe, the first olfactory neuropil in insects, evoked by a set of ecologically relevant plant volatiles. Our results suggest that even between the two phylogenetically distant moth families, basic olfactory coding features are similar. But we also found different coding strategies in the moths' antennal lobe; namely, more specific patterns for chemically similar odorants in the two noctuid species than in the three sphingid species tested. This difference demonstrates the impact of the phylogenetic distance between species from different families despite some parallel life history traits found in both families. Furthermore, pronounced differences in larval and adult diet among the sphingids did not translate into differences in the olfactory code; instead, the three species had almost identical coding patterns. PMID:22496291

  17. Biophysical constraints on lateral inhibition in the olfactory bulb.

    Science.gov (United States)

    McIntyre, Alexa B R; Cleland, Thomas A

    2016-06-01

    The mitral cells (MCs) of the mammalian olfactory bulb (OB) constitute one of two populations of principal neurons (along with middle/deep tufted cells) that integrate afferent olfactory information with top-down inputs and intrinsic learning and deliver output to downstream olfactory areas. MC activity is regulated in part by inhibition from granule cells, which form reciprocal synapses with MCs along the extents of their lateral dendrites. However, with MC lateral dendrites reaching over 1.5 mm in length in rats, the roles of distal inhibitory synapses pose a quandary. Here, we systematically vary the properties of a MC model to assess the capacity of inhibitory synaptic inputs on lateral dendrites to influence afferent information flow through MCs. Simulations using passivized models with varying dendritic morphologies and synaptic properties demonstrated that, even with unrealistically favorable parameters, passive propagation fails to convey effective inhibitory signals to the soma from distal sources. Additional simulations using an active model exhibiting action potentials, subthreshold oscillations, and a dendritic morphology closely matched to experimental values further confirmed that distal synaptic inputs along the lateral dendrite could not exert physiologically relevant effects on MC spike timing at the soma. Larger synaptic conductances representative of multiple simultaneous inputs were not sufficient to compensate for the decline in signal with distance. Reciprocal synapses on distal MC lateral dendrites may instead serve to maintain a common fast oscillatory clock across the OB by delaying spike propagation within the lateral dendrites themselves. PMID:27009162

  18. Olfactory function and alternation learning in eating disorders.

    Science.gov (United States)

    Stein, Daniel; Gross-Isseroff, Ruth; Besserglick, Roni; Ziv, Amir; Mayer, Gad; Yaroslavsky, Amit; Toledano, Anat; Voet, Hillary; Weizman, Abraham; Hermesh, Haggai

    2012-09-01

    Orbitofrontal dysfunction is a prominent feature of obsessive compulsive disorder (OCD). In the present study we assessed orbitofrontal functioning in eating disorders (EDs) which share many features with OCD. For this purpose we studied female adolescent inpatients with anorexia nervosa restricting type (n=40), anorexia nervosa binge/purge type (n=23), a normal weight group including patients with either bulimia nervosa or eating disorder not otherwise specified-purging type (n=33), and 20 non-ED control females. Patients were assessed at admission, and when achieving weight restoration and symptom stabilization at discharge, for depression, non-ED, and ED-related OC symptoms. Orbitofrontal functioning was assessed with an alternation learning task, and with a battery assessing olfactory threshold and discrimination. Control females were assessed once. ED patients of all subtypes performed better on olfactory threshold and discrimination, but not on alternation learning, in comparison to healthy controls. More favorable orbitofrontal functioning was associated with greater ED-related obsessionality. No changes were found in olfactory threshold and discrimination between acutely-ill and symptomatically-stabilized patients. The improvement shown in alternation learning from admission to discharge was suggested to reflect a learning effect rather than being an actual change. Our findings suggest that the better orbitofrontal functioning of ED patients in comparison to healthy controls may represent a core feature of the ED that is independent of malnutrition and deranged eating behaviors, but is associated with ED-related obsessionality. PMID:22858418

  19. Sorting Plastic Waste in Hydrocyclone

    Directory of Open Access Journals (Sweden)

    Ernestas Šutinys

    2011-02-01

    Full Text Available The article presents material about sorting plastic waste in hydrocyclone. The tests on sorting plastic waste were carried out. Also, the findings received from the performed experiment on the technology of sorting plastic waste are interpreted applying an experimental model of the equipment used for sorting plastics of different density.Article in Lithuanian

  20. Interactions with the young down-regulate adult olfactory neurogenesis and enhance the maturation of olfactory neuroblasts in sheep mothers

    OpenAIRE

    Frédéric Levy

    2014-01-01

    New neurons are continuously added in the dentate gyrus and the olfactory bulb of mammalian brain. While numerous environmental factors controlling survival of newborn neurons have been extensively studied, regulation by social interactions is less documented. We addressed this question by investigating the influence of parturition and interactions with the young on neurogenesis in sheep mothers. Using Bromodeoxyuridine, a marker of cell division, in combination with markers of neuronal matur...

  1. Hunger state affects both olfactory abilities and gustatory sensitivity.

    Science.gov (United States)

    Hanci, Deniz; Altun, Huseyin

    2016-07-01

    Chemical senses such as odor, taste and appearance are directly related with appetite. Understanding the relation between appetite and flavor is getting more important due to increasing number of obese patients worldwide. The literature on the studies investigating the change in olfactory abilities and gustatory sensitivity mostly performed using food-related odors and tastes rather than standardized tests were developed to study olfaction and gustation. Therefore, results are inconsistent and the relationship between olfactory and gustatory sensitivity with respect to the actual state of human satiety is still not completely understood. Here, for the first time in literature, we investigated the change in both olfactory abilities and gustatory sensitivity in hunger and in satiety using 123 subjects (37 men, 86 women; mean age 31.4 years, age range 21-41 years). The standardized Sniffin' Sticks Extended Test and Taste Strips were used for olfactory testing and gustatory sensitivity, respectively. TDI score (range 1-48) was calculated as the collective scores of odor threshold (T), odor discrimination (D) and odor identification (I). The evaluation was performed in two successive days where the hunger state of test subjects was confirmed by blood glucose test strips (mean blood glucose level 90.0 ± 5.6 mg/dl in hunger and 131.4 ± 8.1 mg/dl in satiety). The results indicated statistically significant decrease in olfaction in satiety compared to hunger (mean TDI 39.3 ± 1.1 in hunger, 37.4 ± 1.1 in satiety, p < 0.001). The comparison of gustatory sensitivity indicated significantly higher sensitivity to sweet, sour and salty in hunger (p < 0.001), but significantly higher sensitivity to bitter tastant in satiety (p < 0.001). With this prospective study, we were able to show that both olfactory abilities and gustatory sensitivity were affected by hunger state. PMID:25744049

  2. Evidence for increased olfactory receptor gene repertoire size in two nocturnal bird species with well-developed olfactory ability

    Directory of Open Access Journals (Sweden)

    Steiger Silke S

    2009-05-01

    Full Text Available Abstract Background In vertebrates, the molecular basis of the sense of smell is encoded by members of a large gene family, namely olfactory receptor (OR genes. Both the total number of OR genes and the proportion of intact OR genes in a genome may indicate the importance of the sense of smell for an animal. There is behavioral, physiological, and anatomical evidence that some bird species, in particular nocturnal birds, have a well developed sense of smell. Therefore, we hypothesized that nocturnal birds with good olfactory abilities have evolved (i more OR genes and (ii more intact OR genes than closely related and presumably less 'olfaction-dependent' day-active avian taxa. Results We used both non-radioactive Southern hybridization and PCR with degenerate primers to investigate whether two nocturnal bird species that are known to rely on olfactory cues, the brown kiwi (Apteryx australis and the kakapo (Strigops habroptilus, have evolved a larger OR gene repertoire than their day-active, closest living relatives (for kiwi the emu Dromaius novaehollandiae, rhea Rhea americana, and ostrich Struthio camelus and for kakapo the kaka Nestor meridionalis and kea Nestor notabilis. We show that the nocturnal birds did not have a significantly higher proportion of intact OR genes. However, the estimated total number of OR genes was larger in the two nocturnal birds than in their relatives. Conclusion Our results suggest that ecological niche adaptations such as daily activity patterns may have shaped avian OR gene repertoires.

  3. Olfactory dysfunction: Correlation of olfactory bulb volume on MRI and objective olfactometry; Riechstoerungen. Korrelation von objektiver Olfaktometrie und volumetrischer Messungen des Bulbus olfactorius in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Bauknecht, H.C.; Jach, C. [Inst. fuer Radiologie, Universitaetsmedizin Berlin (Germany); Fleiner, F.; Sedlmaier, B.; Goektas, Oe. [Hals-Nasen-Ohrenklinik, Universitaetsmedizin Berlin (Germany)

    2010-02-15

    Purpose: To define the role of olfactory bulb volume measurement by magnetic resonance imaging (MRI) for detecting olfactory dysfunction in comparison with objective olfactometry. Materials and Methods: Thirty patients with suspected olfactory dysfunction (16 women, 14 men; mean age 52 years, range 20-79 years) were examined by MRI and objective olfactometry between January 2006 and January 2009. Olfactory bulb volumes were measured by two neuroradiologists using 3D MR data sets. The olfactory function was categorized as normosmia, hyposmia, and anosmia on the basis of objective olfactometry. Pearson correlation coefficients were calculated for objective olfactometry and olfactory bulb volumes on MRI. ROC analysis was performed to determine whether MRI bulb volumes can serve to predict anosmia or hyposmia. Results: The bulb volumes measured by MRI ranged from 0 to 135.9 mm{sup 3}. Based on olfactometry, anosmia was present in 11 patients (total bulb volume of 15.7 {+-} 23.3 mm{sup 3}), hyposmia in 9 patients (total bulb volume of 50.0 {+-} 25.5 mm{sup 3}), and normosmia in 10 patients (total bulb volume of 110.7 {+-} 21.5 mm{sup 3}). There was good correlation (r>0.9) between objective olfactometry and olfactory bulb volume on MRI. ROC analysis yielded a cut-off value of 32 mm{sup 3} for anosmia, which had a sensitivity of 0.91 and specificity of 0.947. The cut-off value for olfactory dysfunction was 80.7 mm{sup 3} (sensitivity 0.95; specificity of 0.9). Conclusion: The olfactory bulb volume determined by MRI is a suitable parameter for diagnosing complete or partial loss of the sense of smell. (orig.)

  4. Axonal transport of rubidium and thallium in the olfactory nerve of mice

    International Nuclear Information System (INIS)

    Following intranasal administration of radioactive 86Rb+ and 201Tl+ in mice, we observed this direct transport via the olfactory nerve pathway. The 86RbCl and 201TlCl solutions were administered to two groups of mice, the unilateral intranasal and intravenous administration groups. After sacrifice, their heads were divided into the right and left side, which were then subdivided into seven parts; the nasal mucosa and brain regions were separated. Following the unilateral intranasal administration, uptake after 6 h by the olfactory bulb was significantly higher on the ipsilateral side (86Rb, 0.7 %dose; 201Tl, 0.5 %dose) than on the contralateral side (86Rb, 0.08 %dose; 201Tl, 0.15 %dose). Moreover, the 86Rb and 201Tl that accumulated in the olfactory bulb were gradually transported to other brain regions of the olfactory tract, the telencephalon and the diencephalon on the side corresponding to the nostril used for administration. Significant differences were observed between the right and left side of the brain regions 6 and 12 h after administration. Further, 201Tl autoradiography clearly showed striped patterns of dense accumulation, localized in the region around the glomerular layer and granule cell layer of the olfactory bulb and around the olfactory cortex. These results provide clear evidence of axonal transport via the olfactory nerve pathway, from nasal cavity to the olfactory bulb, as well as to the olfactory cortex through the synaptic junctions. The olfactory transport of the 86Rb+ and 201Tl+ is thought to represent the behavior of K+ in the olfactory system

  5. Effects of olfactory dysfunction on sensory evaluation and preparation of foods.

    Science.gov (United States)

    Seo, Han-Seok; Hummel, Thomas

    2009-12-01

    Aim of this study was to investigate the impact of olfactory dysfunction on behavior during sensory evaluation and self-preparation, as well as on sensory perception and pleasantness of green tea and coffee. We compared the intensities of overall odor, flavor, and bitter taste, respectively, and the pleasantness ratings for three different concentrations of green teas and coffees between three groups: young (n=30) and elderly (n=30) with normal olfactory function and elderly (n=30) with olfactory dysfunction. In addition, we compared the subject groups' behavior during sensory testing and preparation of green tea or coffee. As expected, elderly subjects with olfactory dysfunction rated the overall odor intensity less intense than subjects with normal olfactory function. Also, elderly subjects with olfactory dysfunction rated the intensities of overall flavor and bitter taste significantly lower rather than subjects with normal olfactory function in green tea, whereas this result was not obtained in coffee. Compared to young subjects with normal olfactory function, elderly with olfactory dysfunction used more green tea powder to optimize their own green tea. Moreover, olfactory function scores assessed by the "Sniffin' Sticks" test were positively related with sniffing frequency for green tea and with sniffing time for coffee during sensory evaluation. During preparation of the green tea, compared to elderly subjects, young healthy subjects tried to adjust the green tea more frequently by adding green tea powder or water. Such behavioral differences were not present during coffee preparation. In conclusion, our findings demonstrate that olfactory dysfunction affects odor perception and sniffing behavior. However, under the current conditions, it appeared to have no effect on hedonic ratings and self-preparation behaviors. PMID:19619597

  6. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather a...... relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can......, something that is stable over time. Considering neural plasticity, this is not necessarily so. The NCC might change and hence literally change the way a person is conscious. What it is about the NCC that can and might change is, even though it can be relevant for the relation between the brain and...

  7. Anxiety- and Depression-Like States Lead to Pronounced Olfactory Deficits and Impaired Adult Neurogenesis in Mice.

    OpenAIRE

    Siopi, Eleni; Denizet, Marie; Gabellec, Marie-Madeleine; De Chaumont, Fabrice; Olivo-Marin, Jean-Christophe; Guilloux, Jean-Philippe; Lledo, Pierre-Marie; Lazarini, Françoise

    2016-01-01

    International audience Numerous clinical reports underscore the frequency of olfactory impairments in patients suffering from major depressive disorders (MDDs), yet the underlying physiopathological mechanisms remain poorly understood. We hypothesized that one key link between olfactory deficits and MDD lies in hypercortisolemia, a cardinal symptom of MDD. Corticosterone (CORT) is known to negatively correlate with hippocampal neurogenesis, yet its effects on olfactory neurogenesis and olf...

  8. Joining by plastic deformation

    DEFF Research Database (Denmark)

    Mori, Ken-ichiro; Bay, Niels; Fratini, Livan;

    2013-01-01

    As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating opportuni......As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating...

  9. Ultrastructural and histochemical properties of the olfactory system in the japanese jungle crow, Corvus macrorhynchos.

    Science.gov (United States)

    Kondoh, Daisuke; Nashimoto, Mai; Kanayama, Shunsaku; Nakamuta, Nobuaki; Taniguchi, Kazuyuki

    2011-08-01

    Although it has been commonly believed that birds are more dependent on the vision and audition than the olfaction, recent studies indicate that the olfaction of birds is related to the reproductive, homing, and predatory behaviors. In an attempt to reveal the dependence on the olfactory system in crows, we examined the olfactory system of the Japanese jungle crow (Corvus macrorhynchos) by histological, ultrastructural, and lectin histochemical methods. The olfactory epithelium (OE) of the crow occupied remarkably a small area of the nasal cavity (NC) and had the histological and ultrastructural features like other birds. The olfactory bulb (OB) of the crow was remarkably small and did not possess the olfactory ventricle. The left and right halves of the OB were fused in many cases. In the lectin histochemistry, soybean agglutinin (SBA) and Vicia villosa agglutinin (VVA) stained a small number of the receptor cells (RCs) in the OE and the olfactory nerve layer (ONL) and glomerular layer (GL) on the dorsocaudal region of the OB. Phaseolus vulgaris agglutinin-E (PHA-E) stained several RCs in the OE and the ONL and GL on the ventral region of the OB. These results suggest that 1) the crow has less-developed olfactory system than other birds, and 2) the dedicated olfactory receptor cells project their axons to the specific regions of the OB in the crow. PMID:21478653

  10. Neurotrophins are not required for normal embryonic development of olfactory neurons.

    Science.gov (United States)

    Nef, S; Lush, M E; Shipman, T E; Parada, L F

    2001-06-01

    Neurons of the vertebrate olfactory epithelium (OE) regenerate continuously throughout life. The capacity of these neurons to regenerate and make new and precise synaptic connections in the olfactory bulb provides a useful model to study factors that may control or mediate neuronal regeneration. Expression and in vitro studies have suggested potential roles for the neurotrophins in the olfactory system. To directly examine whether neurotrophins are required for olfactory neuron development, we characterized in vivo the role of the neurotrophins in the primary olfactory system. For this, we generated mutant mice for TrkA, TrkB, TrkC, and also for BDNF and NT3 together with P2-IRES-tau-LacZ trangenic mice. Histochemical staining for beta-galactosidase at birth allowed in vivo analysis of the P2 subpopulation of olfactory neurons as well as their projections to the olfactory bulb. Our data indicate that Trk signaling is not required for normal embryonic development of the olfactory system. PMID:11356021

  11. The olfactory deficit and fMRI in the Alzheimer's disease

    International Nuclear Information System (INIS)

    Olfactory deficit is a common symptom occurring at the early stage of Alzheimer's disease, the purpose of this review is to summarize MRI research on olfactory deficit in the Alzheimer's disease and potential clinical relevance of fMRI in this area. (authors)

  12. Assessment of Olfactory Threshold in Patients Undergoing Radiotherapy for Head and Neck Malignancies

    Directory of Open Access Journals (Sweden)

    Mir Mohammad Jalali

    2014-10-01

    Conclusion:  Deterioration in olfactory threshold scores was found at 6 months after initiation of radiation therapy. Provided that these results are reproducible, an evaluation of olfactory functioning in patients with head and neck malignancies using in vivo dosimetry may be useful for determining the optimal dose for patients treated with conformal radiotherapy techniques while avoiding the side effects of radiation.

  13. Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb

    OpenAIRE

    Doyle, Wayne I.; Hammen, Gary F.; Meeks, Julian P.

    2014-01-01

    The mouse accessory olfactory system (AOS) is a specialized sensory pathway for detecting nonvolatile social odors, pheromones, and kairomones. The first neural circuit in the AOS pathway, called the accessory olfactory bulb (AOB), plays an important role in establishing sex-typical behaviors such as territorial aggression and mating. This small (

  14. Metamorphic remodeling of the olfactory organ of the African clawed frog, Xenopus laevis.

    Science.gov (United States)

    Dittrich, Katarina; Kuttler, Josua; Hassenklöver, Thomas; Manzini, Ivan

    2016-04-01

    The amphibian olfactory system undergoes massive remodeling during metamorphosis. The transition from aquatic olfaction in larvae to semiaquatic or airborne olfaction in adults requires anatomical, cellular, and molecular modifications. These changes are particularly pronounced in Pipidae, whose adults have secondarily adapted to an aquatic life style. In the fully aquatic larvae of Xenopus laevis, the main olfactory epithelium specialized for sensing water-borne odorous substances lines the principal olfactory cavity (PC), whereas a separate olfactory epithelium lies in the vomeronasal organ (VNO). During metamorphosis, the epithelium of the PC is rearranged into the adult "air nose," whereas a new olfactory epithelium, the adult "water nose," forms in the emerging middle cavity (MC). Here we performed a stage-by-stage investigation of the anatomical changes of the Xenopus olfactory organ during metamorphosis. We quantified cell death in all olfactory epithelia and found massive cell death in the PC and the VNO, suggesting that the majority of larval sensory neurons is replaced during metamorphosis in both sensory epithelia. The moderate cell death in the MC shows that during the formation of this epithelium some cells are sorted out. Our results show that during MC formation some supporting cells, but not sensory neurons, are relocated from the PC to the MC and that they are eventually eliminated during metamorphosis. Together our findings illustrate the structural and cellular changes of the Xenopus olfactory organ during metamorphosis. PMID:26294036

  15. Matching- and Nonmatching-to-Sample Concept Learning in Rats Using Olfactory Stimuli

    Science.gov (United States)

    April, L. Brooke; Bruce, Katherine; Galizio, Mark

    2011-01-01

    Previous research has shown that rats can learn matching-to-sample relations with olfactory stimuli; however, the specific characteristics of this relational control are unclear. In Experiment 1, 6 rats were trained to either match or nonmatch to sample in a modified operant chamber using common household spices as olfactory stimuli. After…

  16. 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.

  17. The Olfactory Bulb: An Immunosensory Effector Organ during Neurotropic Viral Infections.

    Science.gov (United States)

    Durrant, Douglas M; Ghosh, Soumitra; Klein, Robyn S

    2016-04-20

    In 1935, the olfactory route was hypothesized to be a portal for virus entry into the central nervous system (CNS). This hypothesis was based on experiments in which nasophayngeal infection with poliovirus in monkeys was prevented from spreading to their CNS via transection of olfactory tracts between the olfactory neuroepithelium (ONE) of the nasal cavity and the olfactory bulb (OB). Since then, numerous neurotropic viruses have been observed to enter the CNS via retrograde transport along axons of olfactory sensory neurons whose cell bodies reside in the ONE. Importantly, this route of infection can occur even after subcutaneous inoculation of arboviruses that can cause encephalitis in humans. While the olfactory route is now accepted as an important pathway for viral entry into the CNS, it is unclear whether it provides a way for infection to spread to other brain regions. More recently, studies of antiviral innate and adaptive immune responses within the olfactory bulb suggest it provides early virologic control. Here we will review the data demonstrating that neurotropic viruses gain access to the CNS initially via the olfactory route with emphasis on findings that suggest the OB is a critical immunosensory effector organ that effectively clears virus. PMID:27058872

  18. 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.

  19. Using Single Sensillum Recording to Detect Olfactory Neuron Responses of Bed Bugs to Semiochemicals.

    Science.gov (United States)

    Liu, Feng; Liu, Nannan

    2016-01-01

    The insect olfactory system plays an important role in detecting semiochemicals in the environment. In particular, the antennal sensilla which house single or multiple neurons inside, are considered to make the major contribution in responding to the chemical stimuli. By directly recording action potential in the olfactory sensillum after exposure to stimuli, single sensillum recording (SSR) technique provides a powerful approach for investigating the neural responses of insects to chemical stimuli. For the bed bug, which is a notorious human parasite, multiple types of olfactory sensillum have been characterized. In this study, we demonstrated neural responses of bed bug olfactory sensilla to two chemical stimuli and the dose-dependent responses to one of them using the SSR method. This approach enables researchers to conduct early screening for individual chemical stimuli on the bed bug olfactory sensilla, which would provide valuable information for the development of new bed bug attractants or repellents and benefits the bed bug control efforts. PMID:26862929

  20. Genetic tracing reveals a stereotyped sensory map in the olfactory cortex

    Science.gov (United States)

    Zou, Zhihua; Horowitz, Lisa F.; Montmayeur, Jean-Pierre; Snapper, Scott; Buck, Linda B.

    2001-11-01

    The olfactory system translates myriad chemical structures into diverse odour perceptions. To gain insight into how this is accomplished, we prepared mice that coexpressed a transneuronal tracer with only one of about 1,000 different odorant receptors. The tracer travelled from nasal neurons expressing that receptor to the olfactory bulb and then to the olfactory cortex, allowing visualization of cortical neurons that receive input from a particular odorant receptor. These studies revealed a stereotyped sensory map in the olfactory cortex in which signals from a particular receptor are targeted to specific clusters of neurons. Inputs from different receptors overlap spatially and could be combined in single neurons, potentially allowing for an integration of the components of an odorant's combinatorial receptor code. Signals from the same receptor are targeted to multiple olfactory cortical areas, permitting the parallel, and perhaps differential, processing of inputs from a single receptor before delivery to the neocortex and limbic system.

  1. Air-stepping in neonatal rats: A comparison of L-dopa injection and olfactory stimulation.

    Science.gov (United States)

    Jamon, M; Maloum, I; Riviere, G; Bruguerolle, B

    2002-12-01

    The kinematic parameters of air-stepping induced by 2 methods known to elicit locomotion (olfactory stimulation vs. L-dopa injection) were compared in 3-day-old rats. In the 1st stage, suspended pups were induced to step with an olfactory stimulus of soiled shavings from the nest. In the 2nd stage, they received a subcutaneous injection of L-dopa. Their movements were faster, with a larger amplitude and a phase delay in ipsilateral coupling. Third, the olfactory stimulus was presented in conjunction with L-dopa. The characteristics of locomotion returned to the same level as with the olfactory stimulus alone. These results suggest that olfactory stimulation involves higher nerve centers able to modulate the dopaminergic pathways. They are discussed in relation to the neural structure involved in locomotion. PMID:12492300

  2. Ectopic olfactory neuroblastoma: report of four cases and a review of the literature.

    LENUS (Irish Health Repository)

    Wormald, R

    2011-04-01

    Our objective is to present a short series of four rare cases of ectopic olfactory neuroblastoma. Our methods present four case reports of ectopic olfactory neuroblastoma and a review of the literature for management and treatment of this disease. The results indicate short case series reports of ectopic olfactory neuroblastoma arising from the anterior ethmoidal sinuses, the nasopharynx, the lateral nasal wall and the floor of the nose. The discussion focuses on likely origins of ectopic olfactory neuroblastoma, its clinical features and management. We conclude that ectopic olfactory neuroblastoma is a rare disease. Treatment principles are the same for non-ectopic disease and guided by extension into adjacent structures such as the orbit or anterior cranial fossa and usually involves surgery with or without adjuvant radiotherapy.

  3. What does the nose know? Olfactory function predicts social network size in human

    Science.gov (United States)

    Zou, Lai-quan; Yang, Zhuo-ya; Wang, Yi; Lui, Simon S. Y.; Chen, An-tao; Cheung, Eric F. C.; Chan, Raymond C. K.

    2016-01-01

    Olfaction is an important medium of social communication in humans. However, it is not known whether olfactory function is associated with social network size. This study aimed to explore the underlying neural mechanism between olfactory function and social network. Thirty-one healthy individuals participated in this study. Social network size was estimated using the Social Network Index. Olfactory function was assessed with the Sniffin’ Stick Test. The results showed that there is a significant positive correlation between the size of an individual’s social network and their olfactory sensitivity. We also found that amygdala functional connectivity with the orbitofrontal cortex appeared to be related to olfactory sensitivity and social network size. PMID:27109506

  4. Electroantennogram measurement of the olfactory response of Daphnia spp. and its impairment by waterborne copper.

    Science.gov (United States)

    Simbeya, Christy K; Csuzdi, Catherine E; Dew, William A; Pyle, Greg G

    2012-08-01

    In this study an electroantennogram (EAG) method was developed for use on live daphniids. The EAG response of Daphnia magna and Daphnia pulex to a variety of amino acids was measured. The strongest response measured was elicited by L-arginine and was shown to induce a concentration-dependent response indicating the response is olfactory in nature. Subsequent exposures of D. magna to a low, ecologically-relevant concentration of copper (7.5 μg/L) showed a disruption in EAG function. This study utilizes the development of an EAG method for measuring olfactory acuity of live daphniids and demonstrates that at ecologically-relevant concentrations, the olfactory dysfunction caused by copper can be detected. The EAG technique is a useful tool for investigating the olfactory response of daphniids to odourants at the cellular level and detecting the effects of toxicants on the olfactory acuity of daphniids. PMID:22721843

  5. The nasal cavity of the sheep and its olfactory sensory epithelium.

    Science.gov (United States)

    Barrios, Arthur William; Sanchez Quinteiro, Pablo; Salazar, Ignacio

    2014-12-01

    Macro and microdissection methods, conventional histology and immunohistochemical procedures were used to investigate the nasal cavity and turbinate complex in fetal and adult sheep, with special attention to the ethmoturbinates, the vestibular mucosa, and the septal mucosa posterior to the vomeronasal organ. The ectoturbinates, which are variable in number and size, emerge and develop later than the endoturbinates. The olfactory sensory epithelium is composed of basal cells, neurons, and sustentacular cells organized in strata, but numerous different types are distinguishable on the basis of their thickness and other properties; all variants are present on the more developed turbinates, endoturbinates II and III. Mature neurons and olfactory nerve bundles express olfactory marker protein. We found no structure with the characteristics that in mouse define the septal organ or the ganglion of Grüneberg. Our results thus suggest that in sheep olfactory sensory neurons are exclusively concentrated in the main olfactory epithelium and (to a lesser extent) in the vomeronasal organ. PMID:25213000

  6. Olfactory specialization for perfume collection in male orchid bees.

    Science.gov (United States)

    Mitko, Lukasz; Weber, Marjorie G; Ramirez, Santiago R; Hedenström, Erik; Wcislo, William T; Eltz, Thomas

    2016-05-15

    Insects rely on the olfactory system to detect a vast diversity of airborne molecules in their environment. Highly sensitive olfactory tuning is expected to evolve when detection of a particular chemical with great precision is required in the context of foraging and/or finding mates. Male neotropical orchid bees (Euglossini) collect odoriferous substances from multiple sources, store them in specialized tibial pouches and later expose them at display sites, presumably as mating signals to females. Previous analysis of tibial compounds among sympatric species revealed substantial chemical disparity in chemical composition among lineages with outstanding divergence between closely related species. Here, we tested whether specific perfume phenotypes coevolve with matching olfactory adaptations in male orchid bees to facilitate the location and harvest of species-specific perfume compounds. We conducted electroantennographic (EAG) measurements on males of 15 sympatric species in the genus Euglossa that were stimulated with 18 compounds present in variable proportions in male hind tibiae. Antennal response profiles were species-specific across all 15 species, but there was no conspicuous differentiation between closely related species. Instead, we found that the observed variation in EAG activity follows a Brownian motion model of trait evolution, where the probability of differentiation increases proportionally with lineage divergence time. However, we identified strong antennal responses for some chemicals that are present as major compounds in the perfume of the same species, thus suggesting that sensory specialization has occurred within multiple lineages. This sensory specialization was particularly apparent for semi-volatile molecules ('base note' compounds), thus supporting the idea that such compounds play an important role in chemical signaling of euglossine bees. Overall, our study found no close correspondence between antennal responses and behavioral

  7. Common peptides shed light on evolution of Olfactory Receptors

    Directory of Open Access Journals (Sweden)

    Lancet Doron

    2009-05-01

    Full Text Available Abstract Background Olfactory Receptors (ORs form the largest multigene family in vertebrates. Their evolution and their expansion in the vertebrate genomes was the subject of many studies. In this paper we apply a motif-based approach to this problem in order to uncover evolutionary characteristics. Results We extract deterministic motifs from ORs belonging to ten species using the MEX (Motif Extraction algorithm, thus defining Common Peptides (CPs characteristic to ORs. We identify species-specific CPs and show that their relative abundance is high only in fish and frog, suggesting relevance to water-soluble odorants. We estimate the origins of CPs according to the tree of life and track the gains and losses of CPs through evolution. We identify major CP gain in tetrapods and major losses in reptiles. Although the number of human ORs is less than half of the number of ORs in other mammals, the fraction of lost CPs is only 11%. By examining the positions of CPs along the OR sequence, we find two regions that expanded only in tetrapods. Using CPs we are able to establish remote homology relations between ORs and non-OR GPCRs. Selecting CPs according to their evolutionary age, we bicluster ORs and CPs for each species. Clean biclustering emerges when using relatively novel CPs. Evolutionary age is used to track the history of CP acquisition in the collection of mammalian OR families within HORDE (Human Olfactory Receptor Data Explorer. Conclusion The CP method provides a novel perspective that reveals interesting traits in the evolution of olfactory receptors. It is consistent with previous knowledge, and provides finer details. Using available phylogenetic trees, evolution can be rephrased in terms of CP origins. Supplementary information is also available at http://adios.tau.ac.il/ORPS

  8. Clinical, radiological, surgical, and pathological determinants of olfactory groove schwannoma

    Directory of Open Access Journals (Sweden)

    Andi Sadayandi Ramesh

    2014-01-01

    Full Text Available Background: Olfactory groove schwannomas (OGS are rare anterior cranial fossa base tumors with only 41 cases reported in literature. Olfactory ensheathing cell schwannoma (OECS has similar clinico-radiological features as OGS, but a different cell of origin. In recent years, there is growing interest in OECS as more cases are being reported. Aims: The objective was to study the clinico-radiological features of OGS and define the histological differentiation from OECS. Materials and Methods: We retrospectively analyzed clinical, radiological, surgical and histopathological picture of all cases of OGS managed in our institute. Immuno histochemical studies were performed in these tumors for differentiating from OECS. A comprehensive review of articles published until date describing the operative treatment was done. Results: All three cases had presented with seizures, two had anosmia and papilledema. Gross-total resection was achieved in all our patients. One patient expired in the postoperative period due to septicemia. Positive expression to newer immuno histochemical biomarker CD57 (Leu7, with negative staining to smooth muscle α-actin (SMA was helpful in confirming the diagnosis of OGS and differentiating it from OECS in all our cases. Conclusions: OECS, though rare has to be differentiated from OGS using immuno histochemistry. Gross-total resection of OGS with preservation of olfactory function is often possible and curative. Although these tumors are commonly treated with microsurgical skull base approaches, an endoscopic endonasal approach can be considered in some cases, with repair using mucoperiosteal pedicled flap to prevent cerebrospinal fluid leak.

  9. Individual differences in behavioural plasticities.

    Science.gov (United States)

    Stamps, Judy A

    2016-05-01

    Interest in individual differences in animal behavioural plasticities has surged in recent years, but research in this area has been hampered by semantic confusion as different investigators use the same terms (e.g. plasticity, flexibility, responsiveness) to refer to different phenomena. The first goal of this review is to suggest a framework for categorizing the many different types of behavioural plasticities, describe examples of each, and indicate why using reversibility as a criterion for categorizing behavioural plasticities is problematic. This framework is then used to address a number of timely questions about individual differences in behavioural plasticities. One set of questions concerns the experimental designs that can be used to study individual differences in various types of behavioural plasticities. Although within-individual designs are the default option for empirical studies of many types of behavioural plasticities, in some situations (e.g. when experience at an early age affects the behaviour expressed at subsequent ages), 'replicate individual' designs can provide useful insights into individual differences in behavioural plasticities. To date, researchers using within-individual and replicate individual designs have documented individual differences in all of the major categories of behavioural plasticities described herein. Another important question is whether and how different types of behavioural plasticities are related to one another. Currently there is empirical evidence that many behavioural plasticities [e.g. contextual plasticity, learning rates, IIV (intra-individual variability), endogenous plasticities, ontogenetic plasticities) can themselves vary as a function of experiences earlier in life, that is, many types of behavioural plasticity are themselves developmentally plastic. These findings support the assumption that differences among individuals in prior experiences may contribute to individual differences in behavioural

  10. Persisting Plastic Addiction

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The policy on curbing plastic shopping bag use implemented three years ago has produced mixed results In a bustling farmers’market tucked in a narrow street in Xisanqi residential community in north Beijing,stalls selling vegetables,fruits and other foods line the sidewalk.

  11. Progress in neural plasticity

    Institute of Scientific and Technical Information of China (English)

    POO; Mu-Ming

    2010-01-01

    One of the properties of the nervous system is the use-dependent plasticity of neural circuits.The structure and function of neural circuits are susceptible to changes induced by prior neuronal activity,as reflected by short-and long-term modifications of synaptic efficacy and neuronal excitability.Regarded as the most attractive cellular mechanism underlying higher cognitive functions such as learning and memory,activity-dependent synaptic plasticity has been in the spotlight of modern neuroscience since 1973 when activity-induced long-term potentiation(LTP) of hippocampal synapses was first discovered.Over the last 10 years,Chinese neuroscientists have made notable contributions to the study of the cellular and molecular mechanisms of synaptic plasticity,as well as of the plasticity beyond synapses,including activity-dependent changes in intrinsic neuronal excitability,dendritic integration functions,neuron-glia signaling,and neural network activity.This work highlight some of these significant findings.

  12. Thermodynamics of perfect plasticity

    Czech Academy of Sciences Publication Activity Database

    Roubíček, Tomáš

    2013-01-01

    Roč. 6, č. 1 (2013), s. 193-214. ISSN 1937-1632 R&D Projects: GA ČR GAP201/10/0357 Institutional support: RVO:61388998 Keywords : Prandtl-Reuss plasticity * small strains * Kelvin-Voigt rheology Subject RIV: BA - General Mathematics http://aimsciences.org/journals/home.jsp?journalID=15

  13. Informative document waste plastics

    NARCIS (Netherlands)

    Nagelhout D; Sein AA; Duvoort GL

    1989-01-01

    This "Informative document waste plastics" forms part of a series of "informative documents waste materials". These documents are conducted by RIVM on the indstruction of the Directorate General for the Environment, Waste Materials Directorate, in behalf of the program of acti

  14. Music drives brain plasticity

    OpenAIRE

    Jäncke, Lutz

    2009-01-01

    Music is becoming more and more of an issue in the cognitive neurosciences. A major finding in this research area is that musical practice is associated with structural and functional plasticity of the brain. In this brief review, I will give an overview of the most recent findings of this research area.

  15. Neural circuits containing olfactory neurons are involved in prepulse inhibition of the startle reflex in rats

    Directory of Open Access Journals (Sweden)

    Haichen eNiu

    2015-03-01

    Full Text Available Many neuropsychiatric disorders, such as schizophrenia, have been associated with abnormalities in the function of the olfactory system and prepulse inhibition (PPI of the startle reflex. However, whether these two abnormalities are related is unclear. The present study was designed to determine whether inhibiting olfactory sensory input via the infusion of zinc sulfate (ZnE, 0.17 M, 0.5 ml into the olfactory naris disrupts PPI. Furthermore, lidocaine/MK801 was bilaterally microinjected into the olfactory bulb (OB to examine whether the blockade of olfactory sensory input impairs PPI. To identify the neural projections that connect the olfaction- and PPI-related areas of the CNS, trans-synaptic retrograde tracing using a recombinant pseudorabies virus (PRV was performed. Our results demonstrated that blocking olfactory sensory input altered olfaction-related behavior. At the functional level, we demonstrated that the inhibition of olfactory sensory input impaired PPI of the startle response subsequent to a decrease in c-fos expression in relevant brain regions. Furthermore, the results of a similar and more robust experiment indicated that blocking olfactory sensory input via the microinjection of lidocaine/MK801 into the OB impaired PPI. At the circuit level, based on trans-synaptic retrograde tracing using PRV, we demonstrated that a large portion of the labeled neurons in several regions of the olfactory cortices connected to the pedunculopontine tegmental nucleus (PPTg. Thus, these data suggest that the olfactory system participates in the regulation of PPI and plays a role in the effect of PPI on the startle response in rats.

  16. Odorant-regulated Ca2+ gradients in rat olfactory neurons

    OpenAIRE

    1993-01-01

    Olfactory neurons respond to odors with a change in conductance that mediates an influx of cations including Ca2+. The concomitant increase in [Cai] has been postulated to play a role in the adaptation to maintained odorant stimulation (Kurahashi, T., and T. Shibuya. 1990. Brain Research. 515:261-268. Kramer, R. H., and S. A. Siegelbaum. 1992. Neuron. 9:897-906. Zufall, F., G. M. Shepherd, and S. Firestein. 1991. Proceedings of the Royal Society of London, B. 246:225-230.) We have imaged the ...

  17. Sex effect in mutual olfactory relationships of individually caged rabbits

    OpenAIRE

    Alessandro Finzi; Paolo Negretti; Giovanna Bianconi; Pedro González-Redondo

    2015-01-01

    To assess the sex influence on sniffing behavior of rabbits, sets of three rabbits each were located for seven days in contiguous cages divided by a metal wall with holes that prevented the neighboring rabbits to see each other. A buck was located in the central cage, with a doe at each side. Rabbit behavior was video recorded to observe animals sniffing with the muzzle near the wall. The bucks displayed an olfactory preference towards one of the two does, which decreased in few days. The sig...

  18. Sexual stimulation increases the survival of new cells in the accessory olfactory bulb of the male rat.

    Directory of Open Access Journals (Sweden)

    Nancy M Unda

    2016-03-01

    Full Text Available Sexual behavior in rodents is modulated by the olfactory system. The olfactory bulb (OB is a structure that undergoes continues neurogenesis in adulthood. We have previously shown that 15 days after males rats pace the sexual interaction and ejaculate 1 or 3 times, there is an increase in the density of new cells that reach the accessory olfactory bulb (AOB. The aim of the present study was to evaluate if sexual behavior in male rats increases the density of new neurons that survive 45 days after sexual behavior in the AOB and in the main OB (MOB. Male rats were randomly divided in four groups: 1 Control (Ctr, males without sexual interaction; 2 Exposed (Exp, males only exposed to a sexually receptive female; 3 No pacing (NP, males that mated in conditions in which the female paced the sexual interaction; 4 One ejaculation (1E, males that paced the sexual interaction with a receptive female and ejaculated once; and 5 Three ejaculations (3E, males that paced the sexual interaction and were allowed to ejaculate three times. All males were injected with the DNA synthesis marker 5-bromo-2-deoxyuridine (BrdU, and were tested in one of the above conditions. 45 days later they were sacrificed, and the OBs were processed to identify new cells and evaluate if they had differentiated into neurons. Our data indicate that males that ejaculated 3 times showed an increase in the density of new cells that survive in the posterior part of the granular cell layer of the AOB and have more new neurons that the control group. However, no significant differences were found in the percentage of new cells that differentiate into neurons. No significant increase in the density of new cells was observed in the MOB. Our data show that pacing the sexual interaction until 3 ejaculations increases the density of new cells and neurons in the granular layer of the AOB, confirming that sexual behavior induces long-lasting plastic changes in the OB.

  19. Inducible and targeted deletion of the ERK5 MAP kinase in adult neurogenic regions impairs adult neurogenesis in the olfactory bulb and several forms of olfactory behavior.

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    Yung-Wei Pan

    Full Text Available Although adult-born neurons in the subventricular zone (SVZ and olfactory bulb (OB have been extensively characterized at the cellular level, their functional impact on olfactory behavior is still highly controversial with many conflicting results reported in the literature. Furthermore, signaling mechanisms regulating adult SVZ/OB neurogenesis are not well defined. Here we report that inducible and targeted deletion of erk5, a MAP kinase selectively expressed in the adult neurogenic regions of the adult brain, impairs adult neurogenesis in the SVZ and OB of transgenic mice. Although erk5 deletion had no effect on olfactory discrimination among discrete odorants in the habituation/dishabituation assay, it reduced short-term olfactory memory as well as detection sensitivity to odorants and pheromones including those evoking aggression and fear. Furthermore, these mice show impaired acquisition of odor-cued associative olfactory learning, a novel phenotype that had not been previously linked to adult neurogenesis. These data suggest that ERK5 MAP kinase is a critical kinase signaling pathway regulating adult neurogenesis in the SVZ/OB, and provide strong evidence supporting a functional role for adult neurogenesis in several distinct forms of olfactory behavior.

  20. Animal experiments and clinical application of olfactory ensheathing cell transplantation for treatment of spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Nan Liu; Wei Liu; Baiyu Zhou; Jing Wang; Bing Li

    2008-01-01

    BACKGROUND: The olfactory epithelium can still generate new neurons after arresting its growth and development in the human body. Axons can still be generated and pass through peripheral tissue to reach the olfactory bulb. Thus, olfactory cells have been widely used in the repair of spinal cord injury.OBJECTIVE: Using animal experiments in conjunction with a clinical study of olfactory ensheathing cells, this paper was designed to clarify the function and application prospects of olfactory ensheathing cells, as well as the existing problems with their application. RETRIEVAL STRATEGY: Using the terms "olfactory ensheathing cells, spinal cord injury", we retrieved manuscripts published from January 1990 to June 2007. The languages were limited to English and Chinese. Inclusion criteria: studies addressing the characteristics, basic study, clinical application and prospects of olfactory ensheathing cells; studies that were recently published or were published in high-impact journals. Exclusion criteria: repetitive studies.LITERATURE EVALUATION: The included 29 manuscripts were primarily clinical or basic experimental studies. DATA SYNTHESIS: Following spinal cord injury, spinal neurons die, neurotrophic factors are lacking, and the existing glial scar and cavities hinder axonal growth. One method to repair spinal cord injury is to interfere with the above-mentioned factors based on animal experiments. Myelination and axonal regeneration are the keys to spinal cord injury therapy. Olfactory ensheathing cells can secrete several neurotrophic factors, inhibit horizontal cell reactions, have noticeable neuroprotective effects, and possess a very strong reproductive activity, so they have many advantages in the fields of cell transplantation and gene therapy. However, there still exist many questions and uncertainties, such as the best time window and dose, as well as complications of olfactory ensheathing cell transplantation; precise mechanism of action after olfactory

  1. The maternal brain under stress: Consequences for adaptive peripartum plasticity and its potential functional implications.

    Science.gov (United States)

    Slattery, David A; Hillerer, Katharina M

    2016-04-01

    The peripartum period represents a time during which all mammalian species undergo substantial physiological and behavioural changes, which prepare the female for the demands of motherhood. In addition to behavioural and physiological alterations, numerous brain regions, such as the medial prefrontal cortex, olfactory bulb, medial amygdala and hippocampus are subject to substantial peripartum-associated neuronal, dendritic and synaptic plasticity. These changes, which are temporally- and spatially-distinct, are strongly influenced by gonadal and adrenal hormones, such as estrogen and cortisol/corticosterone, which undergo dramatic fluctuations across this period. In this review, we describe our current knowledge regarding these plasticity changes and describe how stress affects such normal adaptations. Finally, we discuss the mechanisms potentially underlying these neuronal, dendritic and synaptic changes and their functional relevance for the mother and her offspring. PMID:26828151

  2. Streptococcus pneumoniae infection regulates expression of neurotrophic factors in the olfactory bulb and cultured olfactory ensheathing cells.

    Science.gov (United States)

    Ruiz-Mendoza, S; Macedo-Ramos, H; Santos, F A; Quadros-de-Souza, L C; Paiva, M M; Pinto, T C A; Teixeira, L M; Baetas-da-Cruz, W

    2016-03-11

    Streptococcus pneumoniae is the causative agent of numerous diseases including severe invasive infections such as bacteremia and meningitis. It has been previously shown that strains of S. pneumoniae that are unable to survive in the bloodstream may colonize the CNS. However, information on cellular components and pathways involved in the neurotropism of these strains is still scarce. The olfactory system is a specialized tissue in which olfactory receptor neurons (ORNs) are interfacing with the external environment through several microvilli. Olfactory ensheathing cells (OECs) which also form the glial limiting membrane at the surface of the olfactory bulb (OB) are the only cells that ensheathe the ORNs axons. Since previous data from our group showed that OECs may harbor S. pneumoniae, we decided to test whether infection of the OB or OEC cultures modulates the expression levels of neurotrophic factor's mRNA and its putative effects on the activation and viability of microglia. We observed that neurotrophin-3 (NT-3) and glial cell-line-derived neurotrophic factor (GDNF) expression was significantly higher in the OB from uninfected mice than in infected mice. A similar result was observed when we infected OEC cultures. Brain-derived neurotrophic factor (BNDF) expression was significantly lower in the OB from infected mice than in uninfected mice. In contrast, in vitro infection of OECs resulted in a significant increase of BDNF mRNA expression. An upregulation of high-mobility group box 1 (HMGB1) expression was observed in both OB and OEC cultures infected with S. pneumoniae. Moreover, we found that conditioned medium from infected OEC cultures induced the expression of the pro-apoptotic protein cleaved-caspase-3 and an apparently continuous nuclear factor-kappa B (NF-κB) p65 activation in the N13 microglia. Altogether, our data suggest the possible existence of an OEC-pathogen molecular interface, through which the OECs could interfere on the activation and

  3. Comparative analysis of deutocerebral neuropils in Chilopoda (Myriapoda: implications for the evolution of the arthropod olfactory system and support for the Mandibulata concept

    Directory of Open Access Journals (Sweden)

    Sombke Andy

    2012-01-01

    Full Text Available Abstract Background Originating from a marine ancestor, the myriapods most likely invaded land independently of the hexapods. As these two evolutionary lineages conquered land in parallel but separately, we are interested in comparing the myriapod chemosensory system to that of hexapods to gain insights into possible adaptations for olfaction in air. Our study connects to a previous analysis of the brain and behavior of the chilopod (centipede Scutigera coleoptrata in which we demonstrated that these animals do respond to volatile substances and analyzed the structure of their central olfactory pathway. Results Here, we examined the architecture of the deutocerebral brain areas (which process input from the antennae in seven additional representatives of the Chilopoda, covering all major subtaxa, by histology, confocal laser-scan microscopy, and 3D reconstruction. We found that in all species that we studied the majority of antennal afferents target two separate neuropils, the olfactory lobe (chemosensory, composed of glomerular neuropil compartments and the corpus lamellosum (mechanosensory. The numbers of olfactory glomeruli in the different chilopod taxa ranged from ca. 35 up to ca. 90 and the shape of the glomeruli ranged from spheroid across ovoid or drop-shape to elongate. Conclusion A split of the afferents from the (first pair of antennae into separate chemosensory and mechanosensory components is also typical for Crustacea and Hexapoda, but this set of characters is absent in Chelicerata. We suggest that this character set strongly supports the Mandibulata hypothesis (Myriapoda + (Crustacea + Hexapoda as opposed to the Myriochelata concept (Myriapoda + Chelicerata. The evolutionary implications of our findings, particularly the plasticity of glomerular shape, are discussed.

  4. Lesion of the olfactory epithelium accelerates prion neuroinvasion and disease onset when prion replication is restricted to neurons.

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    Jenna Crowell

    Full Text Available Natural prion diseases of ruminants are moderately contagious and while the gastrointestinal tract is the primary site of prion agent entry, other mucosae may be entry sites in a subset of infections. In the current study we examined prion neuroinvasion and disease induction following disruption of the olfactory epithelium in the nasal mucosa since this site contains environmentally exposed olfactory sensory neurons that project directly into the central nervous system. Here we provide evidence for accelerated prion neuroinvasion and clinical onset from the olfactory mucosa after disruption and regeneration of the olfactory epithelium and when prion replication is restricted to neurons. In transgenic mice with neuron restricted replication of prions, there was a reduction in survival when the olfactory epithelium was disrupted prior to intranasal inoculation and there was >25% decrease in the prion incubation period. In a second model, the neurotropic DY strain of transmissible mink encephalopathy was not pathogenic in hamsters by the nasal route, but 50% of animals exhibited brain infection and/or disease when the olfactory epithelium was disrupted prior to intranasal inoculation. A time course analysis of prion deposition in the brain following loss of the olfactory epithelium in models of neuron-restricted prion replication suggests that neuroinvasion from the olfactory mucosa is via the olfactory nerve or brain stem associated cranial nerves. We propose that induction of neurogenesis after damage to the olfactory epithelium can lead to prion infection of immature olfactory sensory neurons and accelerate prion spread to the brain.

  5. Histological and lectin histochemical studies on the main and accessory olfactory bulbs in the Japanese striped snake, Elaphe quadrivirgata.

    Science.gov (United States)

    Kondoh, Daisuke; Wada, Akimi; Endo, Daisuke; Nakamuta, Nobuaki; Taniguchi, Kazuyuki

    2013-01-01

    The main and accessory olfactory bulbs were examined by histological methods and lectin histochemistry in the Japanese striped snake. As the results, the histological properties are similar between the main olfactory bulb and the accessory olfactory bulb. In lectin histochemistry, 21 lectins used in this study showed similar binding patterns in the main olfactory bulb and the accessory olfactory bulb. In detail, 15 lectins stained these olfactory bulbs with similar manner, and 6 lectins did not stain them at all. Two lectins, Lycopersicon esculentum lectin (LEL) and Solanum tuberosum lectin (STL), stained the nerve and glomerular layers and did not stain any other layers in both olfactory bulbs. Four lectins, Soybean agglutinin (SBA), Vicia villosa agglutinin (VVA), Peanut agglutinin (PNA) and Phaseolus vulgaris agglutinin-L (PHA-L) stained the nerve and glomerular layers more intensely than other layers in both olfactory bulbs. In addition, VVA showed the dot-like stainings in the glomeruli of both olfactory bulbs. These findings suggest that the degree of development and the properties of glycoconjugates are similar between the main olfactory bulb and the accessory olfactory bulb in the Japanese striped snake. PMID:23257605

  6. 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.

  7. Expression of homeobox genes in the mouse olfactory epithelium.

    Science.gov (United States)

    Parrilla, Marta; Chang, Isabelle; Degl'Innocenti, Andrea; Omura, Masayo

    2016-10-01

    Homeobox genes constitute a large family of genes widely studied because of their role in the establishment of the body pattern. However, they are also involved in many other events during development and adulthood. The main olfactory epithelium (MOE) is an excellent model to study neurogenesis in the adult nervous system. Analyses of homeobox genes during development show that some of these genes are involved in the formation and establishment of cell diversity in the MOE. Moreover, the mechanisms of expression of odorant receptors (ORs) constitute one of the biggest enigmas in the field. Analyses of OR promoters revealed the presence of homeodomain binding sites in their sequences. Here we characterize the expression patterns of a set of 49 homeobox genes in the MOE with in situ hybridization. We found that seven of them (Dlx3, Dlx5, Dlx6, Msx1, Meis1, Isl1, and Pitx1) are zonally expressed. The homeobox gene Emx1 is expressed in three guanylate cyclase(+) populations, two located in the MOE and the third one in an olfactory subsystem known as Grüneberg ganglion located at the entrance of the nasal cavity. The homeobox gene Tshz1 is expressed in a unique patchy pattern across the MOE. Our findings provide new insights to guide functional studies that aim to understand the complexity of transcription factor expression and gene regulation in the MOE. J. Comp. Neurol. 524:2713-2739, 2016. © 2016 Wiley Periodicals, Inc. PMID:27243442

  8. Olfactory dysfunction and its measurement in the clinic

    Institute of Scientific and Technical Information of China (English)

    Richard L.Doty

    2015-01-01

    The sense of smell is largely taken for granted by laypersons and medical professionals alike.Indeed, its role in determining the flavor of foods and beverages, as well as in warning of, or protecting against, environmental hazards, often goes unrecognized.This is exemplified, in part, by the fact that most patients presenting to medical clinics with "taste" problems are typically subjected to complex brain imaging and gastroenterological tests without the sense of smell even being tested or considered as a basis of the problem.Aside from frank deficiencies in sweet, sour, bitter, salty and savory (umami) sensations, "taste" disorders most commonly reflect inadequate stimulation of the olfactory receptors via the retronasal route;i.e., from volatiles passing to the receptors from the oral cavity through the nasal pharynx.This article describes the two most common procedures for measuring the sense of smell in the clinic and provides examples of the application of these tests to diseases and other disorders frequently associated with smell loss.Basic issues related to olfactory testing and evaluation are addressed.It is pointed out that smell loss, particularly in later life, can be a harbinger for not only a range of neurodegenerative diseases, but can be a prognostic indicator of early mortality.

  9. Olfactory contributions to dehydration-induced anorexia in weanling rats.

    Science.gov (United States)

    Bruno, J P; Hall, W G

    1982-11-01

    By 20 days of age, dehydration produces a clear anorexia, even though weanling rats have had only limited feeding and drinking experience. Their lack of ingestive experience makes weanlings good subjects for studying the physiological mechanisms subserving anorexic phenomena because learned contributions are unlikely to add significant complications. Twenty-day-old rats dehydrated by hypertonic saline injection were anorexic when offered milk or solid food (rat chow), but not when offered sucrose solutions (Experiment I). However, when the scent of almond was associated with sucrose solutions, or with water, intake of these solutions was depressed by dehydration (Experiment II). Thus for dehydrated rats, olfactory stimulation may help produce dehydration-induced anorexia. Making rats anosmic by intransal lavage with ZnSO4 (Experiment III) eliminated the anorexia to almond-scented water and partially eliminated that to milk. For these fluids, an odor cue seems a requirement for the occurrence of dehydration-anorexia. In Experiment IV, we found that dehydration-anorexia did not occur when milk was infused directly into pups' mouths. This finding suggests that the inhibitory process mediating dehydration-anorexia influences the approach to food and not the actual consumatory response that occurs once food is in the mouth. The inhibition of feeding produced by dehydration, therefore, may depend largely on olfactory cues, and seems to operate at a distance, as rats locate and approach food. PMID:7152117

  10. Sex effect in mutual olfactory relationships of individually caged rabbits

    Directory of Open Access Journals (Sweden)

    Alessandro Finzi

    2015-12-01

    Full Text Available To assess the sex influence on sniffing behavior of rabbits, sets of three rabbits each were located for seven days in contiguous cages divided by a metal wall with holes that prevented the neighboring rabbits to see each other. A buck was located in the central cage, with a doe at each side. Rabbit behavior was video recorded to observe animals sniffing with the muzzle near the wall. The bucks displayed an olfactory preference towards one of the two does, which decreased in few days. The significance was p  0.05. The interest of bucks towards the does was also characterized by a frenetic scratching of the separation wall, contemporary with intense sniffing, displayed only for the first 35 min of the first day. The sniffing behavior of does at the central cage housing the male was not so marked as in bucks, and it progressively changed across the trial (p < 0.01. In conclusion, rabbits establish a transitory sex-oriented olfactory relationship with the conspecifics housed in contiguous cages, which looks no longer necessary once the rabbits have recognized each other.

  11. 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.

  12. Parasite and predator risk assessment: nuanced use of olfactory cues.

    Science.gov (United States)

    Sharp, John G; Garnick, Sarah; Elgar, Mark A; Coulson, Graeme

    2015-10-22

    Foraging herbivores face twin threats of predation and parasite infection, but the risk of predation has received much more attention. We evaluated, experimentally, the role of olfactory cues in predator and parasite risk assessment on the foraging behaviour of a population of marked, free-ranging, red-necked wallabies (Macropus rufogriseus). The wallabies adjusted their behaviour according to these olfactory cues. They foraged less, were more vigilant and spent less time at feeders placed in the vicinity of faeces from dogs that had consumed wallaby or kangaroo meat compared with that of dogs feeding on sheep, rabbit or possum meat. Wallabies also showed a species-specific faecal aversion by consuming less food from feeders contaminated with wallaby faeces compared with sympatric kangaroo faeces, whose gastrointestinal parasite fauna differs from that of the wallabies. Combining both parasite and predation cues in a single field experiment revealed that these risks had an additive effect, rather than the wallabies compromising their response to one risk at the expense of the other. PMID:26468246

  13. Detective mice assess relatedness in baboons using olfactory cues.

    Science.gov (United States)

    Célérier, Aurélie; Huchard, Elise; Alvergne, Alexandra; Féjan, Delphine; Plard, Floriane; Cowlishaw, Guy; Raymond, Michel; Knapp, Leslie A; Bonadonna, Francesco

    2010-05-01

    The assessment of relatedness may be crucial in the evolution of socio-sexual behaviour, because it can be associated with fitness benefits mediated by both nepotism and inbreeding avoidance. In this context, one proposed mechanism for kin recognition is 'phenotype matching'; animals might compare phenotypic similarities between themselves and others in order to assess the probability that they are related. Among cues potentially used for kin discrimination, body odours constitute interesting candidates that have been poorly investigated in anthropoid primates so far, because of a mixture of theoretical considerations and methodological/experimental constraints. In this study, we used an indirect approach to examine the similarity in odour signals emitted by related individuals from a natural population of chacma baboons (Papio ursinus). For that purpose, we designed an innovative behavioural tool using mice olfactory abilities in a habituation-discrimination paradigm. We show that: (i) mice can detect odour differences between individuals of same sex and age class in another mammal species, and (ii) mice perceive a higher odour similarity between related baboons than between unrelated baboons. These results suggest that odours may play a role in both the signalling of individual characteristics and of relatedness among individuals in an anthropoid primate. The 'biological olfactometer' developed in this study offers new perspectives to the exploration of olfactory signals from a range of species. PMID:20400623

  14. Scanning laser optical tomography resolves structural plasticity during regeneration in an insect brain.

    Directory of Open Access Journals (Sweden)

    René Eickhoff

    Full Text Available BACKGROUND: Optical Projection Tomography (OPT is a microscopic technique that generates three dimensional images from whole mount samples the size of which exceeds the maximum focal depth of confocal laser scanning microscopes. As an advancement of conventional emission-OPT, Scanning Laser Optical Tomography (SLOTy allows simultaneous detection of fluorescence and absorbance with high sensitivity. In the present study, we employ SLOTy in a paradigm of brain plasticity in an insect model system. METHODOLOGY: We visualize and quantify volumetric changes in sensory information procession centers in the adult locust, Locusta migratoria. Olfactory receptor neurons, which project from the antenna into the brain, are axotomized by crushing the antennal nerve or ablating the entire antenna. We follow the resulting degeneration and regeneration in the olfactory centers (antennal lobes and mushroom bodies by measuring their size in reconstructed SLOTy images with respect to the untreated control side. Within three weeks post treatment antennal lobes with ablated antennae lose as much as 60% of their initial volume. In contrast, antennal lobes with crushed antennal nerves initially shrink as well, but regain size back to normal within three weeks. The combined application of transmission-and fluorescence projections of Neurobiotin labeled axotomized fibers confirms that recovery of normal size is restored by regenerated afferents. Remarkably, SLOTy images reveal that degeneration of olfactory receptor axons has a trans-synaptic effect on second order brain centers and leads to size reduction of the mushroom body calyx. CONCLUSIONS: This study demonstrates that SLOTy is a suitable method for rapid screening of volumetric plasticity in insect brains and suggests its application also to vertebrate preparations.

  15. Introduction to Computational Plasticity

    International Nuclear Information System (INIS)

    The focus of the book on computational plasticity embodies techniques of relevance not only to academic researchers, but also of interest to industrialists engaged in the production of components using bulk or sheet forming processes. Of particular interest is the guidance on how to create modules for use with the commercial system Abaqus for specific types of material behaviour. The book is in two parts, the first of which contains six chapters, starting with microplasticity, but predominantly on continuum plasticity. The first chapter on microplasticty gives a brief description of the grain structure of metals and the existence of slip systems within the grains. This provides an introduction to the concept of incompressibility during plastic deformation, the nature of plastic yield and the importance of the critically resolved shear stress on the slip planes (Schmid's law). Some knowledge of the notation commonly used to describe slip systems is assumed, which will be familiar to students of metallurgy, but anyone with a more general engineering background may need to undertake additional reading to understand the various descriptions. Chapter two introduces one of several yield criteria, that normally attributed to von Mises (though historians of mechanics might argue over who was first to develop the theory of yielding associated with strain energy density), and its two or three-dimensional representation as a yield surface. The expansion of the yield surface during plastic deformation, its translation due to kinematic hardening and the Bauschinger effect in reversed loading are described with a direct link to the material stress-strain curve. The assumption, that the increment of strain is normal to the yield surface, the normality principle, is introduced. Uniaxial loading of an elastic-plastic material is used as an example in which to develop expressions to describe increments in stress and strain. The full presentation of numerous expressions, tensors and

  16. Olfactory nerve response of masu salmon (Oncorhynchus masou Brevoort) and rainbow trout (O. mykiss Walbaum) to clove oil and MS-222

    OpenAIRE

    YAMAMOTO, Yuzo; Woody, Carol A; Shoji, Takayuki; Ueda, Hiroshi

    2008-01-01

    Two anaesthetics, clove oil and MS-222, were examined for their effects on the olfactory nerve response of masu salmon (Oncorhynchus masou) and rainbow trout (O. mykiss). Exposing fish to clove oil for 3 minutes at concentrations of 50 mg/L and 100 mg/L, or for 10 minutes at 50 mg/L, did not significantly reduce their olfactory response. Directly applying clove oil anaesthesia to the olfactory epithelium significantly reduced olfactory response, though olfactory response recovered to 70% and ...

  17. Somatostatin-14-like immunoreactive neurons and fibres in the human olfactory bulb.

    Science.gov (United States)

    Ohm, T G; Braak, E; Probst, A

    1988-01-01

    This study describes the morphological features and the distribution pattern of neurons in the human olfactory bulb which are immunoreactive for an antiserum against the neuropeptide somatostatin-14. Immunoreactive nerve cell bodies were mainly found in the white matter surrounding the cell clusters of the anterior olfactory nucleus. Some immunoreactive neurons were also found scattered throughout the anterior olfactory nucleus and the deeper parts of the inner granule cell layer. Only a few immunoreactive neurons were localized in the glomerular layer and the outer granule cell layer. Immunoreactive fibres were found in all layers of the olfactory bulb. In addition, an impressive number of coiled and kinked immunoreactive fibres were localized within the anterior olfactory nucleus forming a dense plexus. Accumulations of twisted and coiled branches of immunoreactive fibres were rarely found either surrounding or within the olfactory glomerula. The characteristics of somatostatin-14 immunoreactive neurons as seen in the combined pigment-Nissl preparation were studied after decolourizing the chromogen and restaining the preparations with aldehydefuchsin in order to demonstrate the lipofuscin pigment and gallocyanin chrome alum for Nissl material. About 90% of the immunoreactive neurons studied in this manner turned out to be devoid of lipofuscin granules. The remaining 10% displayed different patterns of pigmentation. These findings suggest the presence of different types of somatostatin-14-like immunoreactive neurons in the olfactory bulb of the human adult. PMID:2906788

  18. The sensory basis of olfactory search behavior in banded kokopu ( Galaxias fasciatus).

    Science.gov (United States)

    Baker, Cindy F; Montgomery, John C; Dennis, Todd E

    2002-08-01

    The sensory basis of olfactory search behavior was investigated in the banded kokopu, Galaxias fasciatus, using a flow tank. In the presence of a 2 cm s(-1) current flow, banded kokopu use both water current and chemical information to locate a food odor source. The superficial neuromasts of the lateral line system mediate the rheotactic component of the odor search. A physical block of one olfactory nostril did not affect the olfactory search strategy employed by banded kokopu in still water or in the presence of a current flow. Thus, there is no evidence that banded kokopu perform a bilateral comparison of the olfactory stimulus during their odor search. Previously, olfaction and gustation have been the only sensory systems shown to directly mediate orientation and movement towards odor sources in fish. The use of hydrodynamic cues by fish in location of an olfactory source has been previously proposed, but without direct experimental identification of the sensory systems employed. This study identifies the contributing roles of both olfactory and hydrodynamic sensory systems to the olfactory search repertoire of fish. PMID:12209343

  19. Information processing during sleep: the effect of olfactory stimuli on dream content and dream emotions.

    Science.gov (United States)

    Schredl, Michael; Atanasova, Desislava; Hörmann, Karl; Maurer, Joachim T; Hummel, Thomas; Stuck, Boris A

    2009-09-01

    Research has shown that external stimuli presented during sleep can affect dream content, thus reflecting information processing of the sleeping brain. Olfactory stimuli should have a stronger effect on dream emotions because their processing is linked directly to the limbic system. Because selective olfactory stimulation does not increase arousal activity, intense olfactory stimulation is therefore a prime paradigm for studying information processing during sleep. Fifteen healthy, normosmic volunteers were studied by intranasal chemosensory stimulation during rapid eye movement sleep based on air-dilution olfactometry. For olfactory stimulation, hydrogen sulphide (smell of rotten eggs) and phenyl ethyl alcohol (smell of roses) was used and compared with a control condition without stimulation. The olfactory stimuli affected significantly the emotional content of dreams: the positively toned stimulus yielded more positively toned dreams, whereas the negative stimulus was followed by more negatively toned dreams. Direct incorporations, i.e. the dreamer is smelling something, were not found. The findings indicate that information processing of olfactory stimuli is present in sleep and that the emotional tone of dreams can be influenced significantly depending upon the hedonic characteristic of the stimulus used. It would be interesting to conduct learning experiments (associating specific odours with declarative material) to study whether this declarative material is incorporated into subsequent dreams if the corresponding odour cue is presented during sleep. It would also be interesting to study the effect of positively toned olfactory stimuli on nightmares. PMID:19552703

  20. Odorant-dependent generation of nitric oxide in Mammalian olfactory sensory neurons.

    Directory of Open Access Journals (Sweden)

    Daniela Brunert

    Full Text Available The gaseous signalling molecule nitric oxide (NO is involved in various physiological processes including regulation of blood pressure, immunocytotoxicity and neurotransmission. In the mammalian olfactory bulb (OB, NO plays a role in the formation of olfactory memory evoked by pheromones as well as conventional odorants. While NO generated by the neuronal isoform of NO synthase (nNOS regulates neurogenesis in the olfactory epithelium, NO has not been implicated in olfactory signal transduction. We now show the expression and function of the endothelial isoform of NO synthase (eNOS in mature olfactory sensory neurons (OSNs of adult mice. Using NO-sensitive micro electrodes, we show that stimulation liberates NO from isolated wild-type OSNs, but not from OSNs of eNOS deficient mice. Integrated electrophysiological recordings (electro-olfactograms or EOGs from the olfactory epithelium of these mice show that NO plays a significant role in modulating adaptation. Evidence for the presence of eNOS in mature mammalian OSNs and its involvement in odorant adaptation implicates NO as an important new element involved in olfactory signal transduction. As a diffusible messenger, NO could also have additional functions related to cross adaptation, regeneration, and maintenance of MOE homeostasis.

  1. Immunohistochemical and lectin histochemical studies on the developing olfactory organs of fetal camel.

    Science.gov (United States)

    Ibrahim, Dalia; Taniguchi, Kazumi; Yamamoto, Yoshio; Taniguchi, Kazuyuki; Nakamuta, Nobuaki

    2015-07-01

    Little is known about the development of the olfactory organs of camel. In this study, prenatal development and neuronal differentiation of the vomeronasal organ (VNO) and the olfactory epithelium (OE) of the one-humped camel were studied by immunohistochemistry and lectin histochemistry. A neuronal marker, protein gene product (PGP) 9.5, but not a marker of fully differentiated olfactory receptor cells, olfactory marker protein, intensely labeled the olfactory receptor cells of the VNO and OE at 395 mm, 510 mm, and 530 mm fetal ages, indicating that the olfactory receptor cells are differentiated, but not fully matured both in the VNO and the OE. In 187 mm and 190 mm fetuses, PGP 9.5 yielded faint immunoreactive signals in the VNO, but not in the OE, although the presence of olfactory receptor cells were demonstrated in both tissues by intense WGA and LEL stainings. We conclude that the camel VNO and OE bear differentiated, but still immature receptor cells; in addition, the onset of neuronal differentiation seems to be somewhat earlier in the VNO than in the OE till half of the prenatal life. PMID:25950169

  2. Molecular and neuronal homology between the olfactory systems of zebrafish and mouse.

    Science.gov (United States)

    Saraiva, Luis R; Ahuja, Gaurav; Ivandic, Ivan; Syed, Adnan S; Marioni, John C; Korsching, Sigrun I; Logan, Darren W

    2015-01-01

    Studies of the two major olfactory organs of rodents, the olfactory mucosa (OM) and the vomeronasal organ (VNO), unraveled the molecular basis of smell in vertebrates. However, some vertebrates lack a VNO. Here we generated and analyzed the olfactory transcriptome of the zebrafish and compared it to the olfactory transcriptomes of mouse to investigate the evolutionary and molecular relationship between single and dual olfactory systems. Our analyses revealed a high degree of molecular conservation, with orthologs of mouse olfactory cell-specific markers and all but one of their chemosensory receptor classes expressed in the single zebrafish olfactory organ. Zebrafish chemosensory receptor genes are expressed across a large dynamic range and their RNA abundance correlates positively with the number of neurons expressing that RNA. Thus we estimate the relative proportions of neuronal sub-types expressing different chemosensory receptors. Receptor repertoire size drives the absolute abundance of different classes of neurons, but we find similar underlying patterns in both species. Finally, we identified novel marker genes that characterize rare neuronal populations in both mouse and zebrafish. In sum, we find that the molecular and cellular mechanisms underpinning olfaction in teleosts and mammals are similar despite 430 million years of evolutionary divergence. PMID:26108469

  3. Plasticity modeling & computation

    CERN Document Server

    Borja, Ronaldo I

    2013-01-01

    There have been many excellent books written on the subject of plastic deformation in solids, but rarely can one find a textbook on this subject. “Plasticity Modeling & Computation” is a textbook written specifically for students who want to learn the theoretical, mathematical, and computational aspects of inelastic deformation in solids. It adopts a simple narrative style that is not mathematically overbearing, and has been written to emulate a professor giving a lecture on this subject inside a classroom. Each section is written to provide a balance between the relevant equations and the explanations behind them. Where relevant, sections end with one or more exercises designed to reinforce the understanding of the “lecture.” Color figures enhance the presentation and make the book very pleasant to read. For professors planning to use this textbook for their classes, the contents are sufficient for Parts A and B that can be taught in sequence over a period of two semesters or quarters.

  4. Sustainable reverse logistics for household plastic waste

    OpenAIRE

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than that of virgin plastics. Therefore, it is environmentally and economically beneficial to improve the plastic recycling system to ensure more plastic waste from households is properly collected and pr...

  5. Sub-nanosecond plastic scintillators

    International Nuclear Information System (INIS)

    Quenched plastic scintillators have been developed that yield much faster short decay components and greatly reduced long decay components compared to conventional plastic scintillators. The plastics are produced through the addition of selected quench agents to NE111 plastic scintillator that result in reduced total light output. Eight different agents have been studied. Benzophenone and piperidine are two of the most effective quench agents. Data are presented both for short and long decay components. The plastics are expected to make significant contributions in areas of plasma diagnostics

  6. Plastic food packaging and health

    OpenAIRE

    Raika Durusoy; Ali Osman Karababa

    2011-01-01

    Plastics have a wide usage in our daily lives. One of their uses is for food packaging and food containers. The aim of this review is to introduce different types of chemicals that can leach from food packaging plastics into foods and cause human exposure and to mention their effects on health. The types of plastics were reviewed under the 13 headings in Turkish Codex Alimentarius and plastics recycling symbols were provided to enable the recognition of the type of plastic when applicable. Ch...

  7. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Science.gov (United States)

    2012-09-06

    ... determination was published in the Federal Register on Monday, July 23, 2012 (77 FR 43123). ] At the request of... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics Acquisitions Inc., Including On-Site Leased Workers From Kelly Services and...

  8. Anisotropic Plasticity and Viscoplasticity

    OpenAIRE

    Schick, David

    2004-01-01

    Plastic anisotropy effects may be described in a phenomenological model by employing in the constitutive theory a set of internal variables, which are defined suitably. These variables have to model the hardening response of the material under consideration to describe e.g. the rotation of some symmetry axes. Such axes are imagined to be related with the development of the material substructure assumed, or, correspondingly, with the state variables characterizing this development. The objecti...

  9. Psychotherapy and brain plasticity

    OpenAIRE

    Collerton, Daniel

    2013-01-01

    In this paper, I will review why psychotherapy is relevant to the question of how consciousness relates to brain plasticity. A great deal of the research and theorizing on consciousness and the brain, including my own on hallucinations for example (Collerton and Perry, 2011) has focused upon specific changes in conscious content which can be related to temporal changes in restricted brain systems. I will argue that psychotherapy, in contrast, allows only a focus on holistic aspects of conscio...

  10. Advances in Plastic Surgery

    OpenAIRE

    McDonald, Harold D.; Luis O. Vasconez

    1982-01-01

    Recent progress in plastic surgery has been rapid and many new techniques have been developed. Reconstructive procedures have been advanced by a better understanding of the anatomy of the blood supply to skin and muscle, with the subsequent development of the use of axial flaps, musculocutaneous flaps and neurosensory flaps. Burn treatment has advanced greatly, making it possible to successfully treat larger and more complicated burns. The development of microsurgery has made possible free-fl...

  11. Microelectronics plastic molded packaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R. [Ktech Corp., Albuquerque, NM (United States); Palmer, D.W.; Peterson, D.W. [Sandia National Lab., Albuquerque, NM (United States)] [and others

    1997-02-01

    The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.

  12. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. PMID:21356588

  13. Phospholipase C and diacylglycerol mediate olfactory responses to amino acids in the main olfactory epithelium of an amphibian.

    Science.gov (United States)

    Sansone, Alfredo; Hassenklöver, Thomas; Syed, Adnan S; Korsching, Sigrun I; Manzini, Ivan

    2014-01-01

    The semi-aquatic lifestyle of amphibians represents a unique opportunity to study the molecular driving forces involved in the transition of aquatic to terrestrial olfaction in vertebrates. Most amphibians have anatomically segregated main and vomeronasal olfactory systems, but at the cellular and molecular level the segregation differs from that found in mammals. We have recently shown that amino acid responses in the main olfactory epithelium (MOE) of larval Xenopus laevis segregate into a lateral and a medial processing stream, and that the former is part of a vomeronasal type 2 receptor expression zone in the MOE. We hypothesized that the lateral amino acid responses might be mediated via a vomeronasal-like transduction machinery. Here we report that amino acid-responsive receptor neurons in the lateral MOE employ a phospholipase C (PLC) and diacylglycerol-mediated transduction cascade that is independent of Ca(2+) store depletion. Furthermore, we found that putative transient receptor potential (TRP) channel blockers inhibit most amino acid-evoked responses in the lateral MOE, suggesting that ion channels belonging to the TRP family may be involved in the signaling pathway. Our data show, for the first time, a widespread PLC- and diacylglycerol-dependent transduction cascade in the MOE of a vertebrate already possessing a vomeronasal organ. PMID:24489954

  14. Phospholipase C and diacylglycerol mediate olfactory responses to amino acids in the main olfactory epithelium of an amphibian.

    Directory of Open Access Journals (Sweden)

    Alfredo Sansone

    Full Text Available The semi-aquatic lifestyle of amphibians represents a unique opportunity to study the molecular driving forces involved in the transition of aquatic to terrestrial olfaction in vertebrates. Most amphibians have anatomically segregated main and vomeronasal olfactory systems, but at the cellular and molecular level the segregation differs from that found in mammals. We have recently shown that amino acid responses in the main olfactory epithelium (MOE of larval Xenopus laevis segregate into a lateral and a medial processing stream, and that the former is part of a vomeronasal type 2 receptor expression zone in the MOE. We hypothesized that the lateral amino acid responses might be mediated via a vomeronasal-like transduction machinery. Here we report that amino acid-responsive receptor neurons in the lateral MOE employ a phospholipase C (PLC and diacylglycerol-mediated transduction cascade that is independent of Ca(2+ store depletion. Furthermore, we found that putative transient receptor potential (TRP channel blockers inhibit most amino acid-evoked responses in the lateral MOE, suggesting that ion channels belonging to the TRP family may be involved in the signaling pathway. Our data show, for the first time, a widespread PLC- and diacylglycerol-dependent transduction cascade in the MOE of a vertebrate already possessing a vomeronasal organ.

  15. Interfacial interactions between plastic particles in plastics flotation.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation. PMID:26337962

  16. The Olfactory Groove Schwannoma Attached to the Cribriform Plate: A Case Report

    OpenAIRE

    Kim, Deok Young; Yoon, Pyeong Ho; Kie, Jeong Hae; Yang, Kook Hee

    2015-01-01

    The olfactory groove schwannoma is a quite rare tumor. We report a case of a 49-year-old woman with an olfactory groove schwannoma attached to the cribriform plate without olfactory dysfunction. She had no specific neurological symptoms other than a headache, and resection of the tumor showed it to be a schwannoma. About 19 months after the operation, a follow-up MRI showed no evidence of tumor recurrence. Surgical resection through subfrontal approach could be one of the curative modality in...

  17. Olfactory Stimulation Selectively Modulates the OFF Pathway in the Retina of Zebrafish

    OpenAIRE

    Esposti, Federico; Johnston, Jamie; Rosa, Juliana M.; Leung, Kin-Mei; Lagnado, Leon

    2013-01-01

    Summary Cross-modal regulation of visual performance by olfactory stimuli begins in the retina, where dopaminergic interneurons receive projections from the olfactory bulb. However, we do not understand how olfactory stimuli alter the processing of visual signals within the retina. We investigated this question by in vivo imaging activity in transgenic zebrafish expressing SyGCaMP2 in bipolar cell terminals and GCaMP3.5 in ganglion cells. The food-related amino acid methionine reduced the gai...

  18. A cGMP-signaling pathway in a subset of olfactory sensory neurons

    OpenAIRE

    Meyer, M.R.; Angele, A.; Kremmer, E; Kaupp, U B; F. Müller

    2000-01-01

    It is well established that signal transduction in sensory neurons of the rat olfactory epithelium involves a cAMP-signaling pathway. However, a small number of olfactory neurons specifically express cGMP-signaling components, namely a guanylyl cyclase (GC-D) and a cGMP-stimulated phosphodiesterase (PDE2). Here, we show that this subset of olfactory neurons expressing GC-D and PDE2 does also express the subunit of a cGMP-selective cyclic nucleotide-gated (CNG) channel that has been previously...

  19. Effects of starvation on the olfactory responses of the blood-sucking bug Rhodnius prolixus

    OpenAIRE

    Reisenman, Carolina E.; Lee, Yan; Gregory, Teresa; Guerenstein, Pablo G.

    2013-01-01

    Blood-sucking insects use olfactory cues in a variety of behavioral contexts, including host-seeking and aggregation. In triatomines, which are obligated blood-feeders, it has been shown that the response to CO2, a host-associated olfactory cue used almost universally by blood-sucking insects, is modulated by hunger. Host-finding is a particularly dangerous task for these insects, as their hosts are also their potential predators. Here we investigated whether olfactory responses to host-deriv...

  20. Tea classification based on artificial olfaction using bionic olfactory neural network

    OpenAIRE

    X. L. Yang; Fu, J.; Lou, Z G; L. Y. Wang; Li, G.; Freeman, Walter J III

    2006-01-01

    Based on the research on mechanism of biological olfactory system, we constructed a K-set, which is a novel bionic neural network. Founded on the groundwork of K0, KI and KII sets, the KIII set in the K-set hierarchy simulates the whole olfactory neural system. In contrast to the conventional artificial neural networks, the KIII set operates in nonconvergent 'chaotic' dynamical modes similar to the biological olfactory system. In this paper, an application of electronic nose-brain for tea cla...

  1. Imaging of olfactory bulb and gray matter volumes in brain areas associated with olfactory function in patients with Parkinson's disease and multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shun, E-mail: shchen_2013@163.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Tan, Hong-yu, E-mail: honhyutan@21cn.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Wu, Zhuo-hua, E-mail: zhh88@126.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Sun, Chong-peng, E-mail: Suncp2002@gmail.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); He, Jian-xun, E-mail: xundog@163.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); Li, Xin-chun, E-mail: xinchunli@163.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); Shao, Ming, E-mail: yimshao@126.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China)

    2014-03-15

    We explored if magnetic resonance imaging sequences might aid in the clinical differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). We measured the volumes of the olfactory bulb, the olfactory tract, and olfaction-associated cortical gray matter in 20 IPD patients, 14 MSA patients, and 12 normal subjects, using high-resolution magnetic resonance imaging sequences in combination with voxel-based statistical analysis. We found that, compared to normal subjects and MSA patients, the volumes of the olfactory bulb and tract were significantly reduced in IPD patients. The gray matter volume of IPD patients decreased in the following order: the olfactory area to the right of the piriform cortex, the right amygdala, the left entorhinal cortex, and the left occipital lobe. Further, the total olfactory bulb volume of IPD patients was associated with the duration of disease. The entorhinal cortical gray matter volume was negatively associated with the UPDRS III score. Conclusion: Structural volumes measured by high-resolution magnetic resonance imaging may potentially be used for differential diagnosis of IPD from MSA.

  2. Imaging of olfactory bulb and gray matter volumes in brain areas associated with olfactory function in patients with Parkinson's disease and multiple system atrophy

    International Nuclear Information System (INIS)

    We explored if magnetic resonance imaging sequences might aid in the clinical differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). We measured the volumes of the olfactory bulb, the olfactory tract, and olfaction-associated cortical gray matter in 20 IPD patients, 14 MSA patients, and 12 normal subjects, using high-resolution magnetic resonance imaging sequences in combination with voxel-based statistical analysis. We found that, compared to normal subjects and MSA patients, the volumes of the olfactory bulb and tract were significantly reduced in IPD patients. The gray matter volume of IPD patients decreased in the following order: the olfactory area to the right of the piriform cortex, the right amygdala, the left entorhinal cortex, and the left occipital lobe. Further, the total olfactory bulb volume of IPD patients was associated with the duration of disease. The entorhinal cortical gray matter volume was negatively associated with the UPDRS III score. Conclusion: Structural volumes measured by high-resolution magnetic resonance imaging may potentially be used for differential diagnosis of IPD from MSA

  3. 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.

  4. Update on the olfactory receptor (OR gene superfamily

    Directory of Open Access Journals (Sweden)

    Olender Tsviya

    2008-09-01

    Full Text Available Abstract The olfactory receptor gene (OR superfamily is the largest in the human genome. The superfamily contains 390 putatively functional genes and 465 pseudogenes arranged into 18 gene families and 300 subfamilies. Even members within the same subfamily are often located on different chromosomes. OR genes are located on all autosomes except chromosome 20, plus the X chromosome but not the Y chromosome. The gene:pseudogene ratio is lowest in human, higher in chimpanzee and highest in rat and mouse -- most likely reflecting the greater need of olfaction for survival in the rodent than in the human. The OR genes undergo allelic exclusion, each sensory neurone expressing usually only one odourant receptor allele; the mechanism by which this phenomenon is regulated is not yet understood. The nomenclature system (based on evolutionary divergence of genes into families and subfamilies of the OR gene superfamily has been designed similarly to that originally used for the CYP gene superfamily.

  5. Differential odor processing in two olfactory pathways in the honeybee.

    Science.gov (United States)

    Yamagata, Nobuhiro; Schmuker, Michael; Szyszka, Paul; Mizunami, Makoto; Menzel, Randolf

    2009-01-01

    An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN). Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons) of two types of PNs - lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentration, which may be optimized for fine, concentration-invariant odor discrimination. In mPN boutons, however, we found clear rising concentration dependence, broader tuning profiles at a high concentration, which may be optimized for concentration coding. In addition, we found more mixture suppression in lPNs than in mPNs, indicating lPNs better adaptation for synthetic mixture processing. These results suggest a functional division of odor processing in both PN types. PMID:20198105

  6. Differential odor processing in two olfactory pathways in the honeybee

    Directory of Open Access Journals (Sweden)

    Nobuhiro Yamagata

    2009-12-01

    Full Text Available An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN. Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons of two types of PNs - lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentration, which may be optimized for fine, concentration-invariant odor discrimination. In mPN boutons, however, we found clear rising concentration dependence, broader tuning profiles at a high concentration, which may be optimized for concentration coding. In addition, we found more mixture suppression in lPNs than in mPNs, indicating lPNs better adaptation for synthetic mixture processing. These results suggest a functional division of odor processing in both PN types.

  7. Ectopic primary olfactory neuroblastoma of the maxillary sinus.

    Science.gov (United States)

    Holmes, Margaret; Su, Shirley Y; Bell, Diana

    2016-06-01

    Olfactory neuroblastoma (ONB) is a rare malignant tumor. Although the vast majority of cases arise in the nasal cavity, ONB is rarely reported in ectopic locations. We report a case of ONB in the maxillary sinus. A 63-year-old woman presented with left-sided nasal obstruction and epistaxis. Magnetic resonance imaging showed a nonenhancing left maxillary sinus tumor. Histologic sections showed ONB, Hyams grade IV, invading bone, skeletal muscle, and adjacent fibroadipose tissue. It is essential to be accurate when diagnosing sinonasal tumors because the differential diagnosis is broad, and one must consider the possibility of ectopic ONB, although it is rare. The behavior of ONB and other neuroendocrine tumors of the sinonasal region is quite different, and there are varied approaches to treatment. Therefore, an accurate diagnosis as well as correct grade and stage must be assigned. PMID:27180059

  8. Wnt5a controls neurite development in olfactory bulb interneurons

    Directory of Open Access Journals (Sweden)

    Youngshik Choe

    2011-06-01

    Full Text Available Neurons born in the postnatal SVZ (subventricular zone must migrate a great distance before becoming mature interneurons of the OB (olfactory bulb. During migration immature OB neurons maintain an immature morphology until they reach their destination. While the morphological development of these cells must be tightly regulated, the cellular pathways responsible are still largely unknown. Our results show that the non-canonical Wnt pathway induced by Wnt5a is important for the morphological development of OB interneurons both in vitro and in vivo. Additionally, we demonstrate that non-canonical Wnt signalling works in opposition to canonical Wnt signalling in neural precursors from the SVZ in vitro. This represents a novel role for Wnt5a in the development of OB interneurons and suggests that canonical and non-canonical Wnt pathways dynamically oppose each other in the regulation of dendrite maturation.

  9. Superior Orthonasal but Not Retronasal Olfactory Skills in Congenital Blindness

    DEFF Research Database (Denmark)

    Gagnon, Lea; Ismaili, Abd Rahman Alaoui; Ptito, Maurice;

    2015-01-01

    using grocery-available food powders. Results showed that blind subjects were significantly faster and tended to be better at identifying odours presented orthonasally. This was not the case when odorants were presented retronasally. We also found a significant group x route interaction, showing......Sight is undoubtedly important for finding and appreciating food, and cooking. Blind individuals are strongly impaired in finding food, limiting the variety of flavours they are exposed to. We have shown before that compared to sighted controls, congenitally blind individuals have enhanced...... their sighted counterparts. These results confirm that orthonasal but not retronasal olfactory perception is enhanced in congenital blindness, a result that is concordant with the reduced food variety exposure in this group....

  10. Olfactory Reference Syndrome: Diagnostic Criteria and Differential Diagnosis

    Directory of Open Access Journals (Sweden)

    Lochner C

    2003-01-01

    Full Text Available Olfactory reference syndrome (ORS has been defined as a psychiatric condition characterized by persistent preoccupation about body odour accompanied by shame, embarrassment, significant distress, avoidance behaviour and social isolation. ORS has however not been included in the Diagnostic and Statistical Manual of Mental Disorders (4th edition (DSM-IV and, given that its primary symptoms may be found in various other disorders, differential diagnosis can be problematic. Using an illustrative case of ORS, we propose diagnostic criteria for ORS. We also argue that ORS represents a unique cluster of symptoms that can be delineated as a separate diagnostic entity, and that ORS falls on a spectrum of social anxiety disorders that includes social anxiety disorder, taijin kyofusho, and body dysmorphic disorder.

  11. Direct liquefaction of plastics and coprocessing of coal with plastics

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, G.P.; Feng, Z.; Mahajan, V. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-31

    The objectives of this work were to optimize reaction conditions for the direct liquefaction of waste plastics and the coprocessing of coal with waste plastics. In previous work, the direct liquefaction of medium and high density polyethylene (PE), polypropylene (PPE), poly(ethylene terephthalate) (PET), and a mixed plastic waste, and the coliquefaction of these plastics with coals of three different ranks was studied. The results established that a solid acid catalyst (HZSM-5 zeolite) was highly active for the liquefaction of the plastics alone, typically giving oil yields of 80-95% and total conversions of 90-100% at temperatures of 430-450 {degrees}C. In the coliquefaction experiments, 50:50 mixtures of plastic and coal were used with a tetralin solvent (tetralin:solid = 3:2). Using approximately 1% of the HZSM-5 catalyst and a nanoscale iron catalyst, oil yields of 50-70% and total conversion of 80-90% were typical. In the current year, further investigations were conducted of the liquefaction of PE, PPE, and a commingled waste plastic obtained from the American Plastics Council (APC), and the coprocessing of PE, PPE and the APC plastic with Black Thunder subbituminous coal. Several different catalysts were used in these studies.

  12. Fabrication of plastic biochips

    International Nuclear Information System (INIS)

    A versatile surface functionalization procedure based on rf magnetron sputtering of silica was performed on poly(methylmethacrylate), polycarbonate, polypropylene, and cyclic olefin copolymers (Topas 6015). The hybrid thermoplastic surfaces were characterized by x-ray photoelectron spectrometer analysis and contact angle measurements. The authors then used these hybrid materials to perform a sandwich assay targeting an HIV-1 antibody using fluorescent detection and biotinylated peptides immobilized using the bioaffinity of biotin-neutravidin. They found a limit of detection similar to arrays on glass surfaces and believed that this plastic biochip platform may be used for the development of disposable immunosensing and diagnostic applications.

  13. Plastics pipe couplings

    International Nuclear Information System (INIS)

    A method is described of making a pipe coupling of the type comprising a plastics socket and a resilient annular sealing member secured in the mouth thereof, in which the material of at least one component of the coupling is subjected to irradiation with high energy radiation whereby the material is caused to undergo cross-linking. As examples, the coupling may comprise a polyethylene or plasticised PVC socket the material of which is subjected to irradiation, and the sealing member may be moulded from a thermoplastic elastomer which is subjected to irradiation. (U.K.)

  14. Plastic star coupler

    Science.gov (United States)

    Yuuki, Hayato; Ito, Takeharu; Sugimoto, Tetsuo

    1991-12-01

    We applied an ultrasonic welding method for the bonding of plastic fibers, and obtained many types of optical star couplers for optical communication systems. It enables the manufacturing of optical components with low loss without damaging the clad layer except for the welding surface. Therefore, they have some merits, such as low loss, small size, light weight, and low cost. The 4-ports (2 X 2) star coupler of 1000 micrometers diam APF has 0.7 dB excess loss at most, and the welding length is 20 mm.

  15. Handbook of plastic optics

    CERN Document Server

    Bäumer, Stefan

    2011-01-01

    A coherent overview of the current status of injection molded optics, describing in detail all aspects of plastic optics, from design issues to production technology and quality control. This updated second edition is supplemented by a chapter on the equipment and process of injection wells as well as a look at recent applications.The contributors, each one a leading expert in their discipline, have either a background in or strong ties to the industry, thus combining a large amount of practical experience.With its focus firmly set on practical applications, this is an indispensable re

  16. Morphological, olfactory, and vocal development in big brown bats

    Directory of Open Access Journals (Sweden)

    Heather W. Mayberry

    2014-12-01

    Full Text Available Using a within subjects design, we documented morphological, bioacoustical and behavioral developmental changes in big brown bats. Eptesicus fuscus pups are born naked and blind but assume an adult-like appearance by post-natal day (PND 45 and flight by PND 30. Adult females use spatial memory, acoustic and olfactory cues to reunite with offspring, but it is unclear if pups can recognize maternal scents. We tested the olfactory discrimination abilities of young E. fuscus pups and found they exhibited no odor preferences. Pups also emit distinct vocalizations called isolation calls (i-calls that facilitate mother-offspring reunions, but how pups shift their vocalizations from i-calls to downward frequency modulated (FM sweeps used in echolocation remains unclear. Between PND 0–9, pups emitted mainly long duration, tonal i-calls rich in harmonics, but after they switched to short duration, downward FM sweeps with fewer harmonics. Call maximum frequency and repetition rate showed minor changes across development. Signal duration, bandwidth, and number of harmonics decreased, whereas the maximum, minimum and bandwidth of the fundamental, and peak spectral frequency all increased. We recorded vocalizations during prolonged maternal separation and found that isolated pups called longer and at a faster rate, presumably to signal for maternal assistance. To assess how PND 13 pups alter their signals during interactions with humans we compared spontaneous and provoked vocalizations and found that provoked calls were spectrally and temporally more similar to those of younger bats suggesting that pups in distress emit signals that sound like younger bats to promote maternal assistance.

  17. Lola regulates Drosophila olfactory projection neuron identity and targeting specificity

    Directory of Open Access Journals (Sweden)

    Giniger Edward

    2007-07-01

    Full Text Available Abstract Background Precise connections of neural circuits can be specified by genetic programming. In the Drosophila olfactory system, projection neurons (PNs send dendrites to single glomeruli in the antenna lobe (AL based upon lineage and birth order and send axons with stereotyped terminations to higher olfactory centers. These decisions are likely specified by a PN-intrinsic transcriptional code that regulates the expression of cell-surface molecules to instruct wiring specificity. Results We find that the loss of longitudinals lacking (lola, which encodes a BTB-Zn-finger transcription factor with 20 predicted splice isoforms, results in wiring defects in both axons and dendrites of all lineages of PNs. RNA in situ hybridization and quantitative RT-PCR suggest that most if not all lola isoforms are expressed in all PNs, but different isoforms are expressed at widely varying levels. Overexpression of individual lola isoforms fails to rescue the lola null phenotypes and causes additional phenotypes. Loss of lola also results in ectopic expression of Gal4 drivers in multiple cell types and in the loss of transcription factor gene lim1 expression in ventral PNs. Conclusion Our results indicate that lola is required for wiring of axons and dendrites of most PN classes, and suggest a need for its molecular diversity. Expression pattern changes of Gal4 drivers in lola-/- clones imply that lola normally represses the expression of these regulatory elements in a subset of the cells surrounding the AL. We propose that Lola functions as a general transcription factor that regulates the expression of multiple genes ultimately controlling PN identity and wiring specificity.

  18. Evidence for a Notch1-mediated transition during olfactory ensheathing cell development.

    Science.gov (United States)

    Miller, Sophie R; Perera, Surangi N; Benito, Cristina; Stott, Simon R W; Baker, Clare V H

    2016-09-01

    Olfactory ensheathing cells (OECs) are a unique glial population found in both the peripheral and central nervous system: they ensheath bundles of unmyelinated olfactory axons from their peripheral origin in the olfactory epithelium to their central synaptic targets in the glomerular layer of the olfactory bulb. Like all other peripheral glia (Schwann cells, satellite glia, enteric glia), OECs are derived from the embryonic neural crest. However, in contrast to Schwann cells, whose development has been extensively characterised, relatively little is known about their normal development in vivo. In the Schwann cell lineage, the transition from multipotent Schwann cell precursor to immature Schwann cell is promoted by canonical Notch signalling. Here, in situ hybridisation and immunohistochemistry data from chicken, mouse and human embryos are presented that suggest a canonical Notch-mediated transition also occurs during OEC development. PMID:27271278

  19. Microelectrode Recording of Tissue Neural Oscillations for a Bionic Olfactory Biosensor

    Institute of Scientific and Technical Information of China (English)

    Qingjun Liu; Fenni Zhang; Ning Hu; Hua Wang; Kuen Jimmy Hsia; Ping Wang

    2012-01-01

    In olfactory research,neural oscillations exhibit excellent temporal regularity,which are functional and necessary at the physiological and cognitive levels.In this paper,we employed a bionic tissue biosensor which treats intact epithelium as sensing element to record the olfactory oscillations extracellularly.After being stimulated by odorant of butanedione,the olfactory receptor neurons generated different kinds of oscillations,which can be described as pulse firing oscillation,transient firing oscillation,superposed firing oscillation,and sustained firing oscillation,according to their temporal appearances respectively.With a time-frequency analysis of sonogram,the oscillations also demonstrated different frequency properties,such as δ,θ,α,β and γ oscillations.The results suggest that the bionic biosensor cooperated with sonogram analysis can well improve the investigation of olfactory oscillations,and provide a novel model for artificial olfaction sensor design.

  20. One nose, one brain: contribution of the main and accessory olfactory system to chemosensation

    Directory of Open Access Journals (Sweden)

    Carla eMucignat

    2012-11-01

    Full Text Available The accessory olfactory system is present in most tetrapods. It is involved in the perception of chemical stimuli, being implicated also in the detection of pheromone. However, it is sensitive also to some common odorant molecules, which have no clear implication in intraspecific chemical communication. The accessory olfactory system may complement the main olfactory system, and may contribute different perceptual features to the construction of a unitary representation, which merges the different chemosensory qualities. Crosstalk between the main and accessory olfactory systems occurs at different levels of central processing, in brain areas where the inputs from the two systems converge. Interestingly, centrifugal projections from more caudal brain areas are deeply involved in modulating both main and accessory sensory processing. A high degree of interaction between the two systems may be conceived, and partial overlapping appears to occur in many functions. Therefore, the central chemosensory projections merge inputs from different organs to obtain a complex chemosensory picture.

  1. 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.

  2. Computer-controlled stimulation for functional magnetic resonance imaging studies of the neonatal olfactory system

    OpenAIRE

    Arichi, T.; Gordon-Williams, R; Allievi, A.; Groves, AM; Burdet, E.; Edwards, AD

    2013-01-01

    Aim Olfactory sensation is highly functional early in human neonatal life, with studies suggesting that odours can influence behaviour and infant–mother bonding. Due to its good spatial properties, blood oxygen level–dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) has the potential to rapidly advance our understanding of the neural activity which underlies the development of olfactory perception in this key period. We aimed to design an ‘olfactometer’ specifically for u...

  3. The functional significance of newly born neurons integrated into olfactory bulb circuits

    OpenAIRE

    Sakamoto, Masayuki; Kageyama, Ryoichiro; Imayoshi, Itaru

    2014-01-01

    The olfactory bulb (OB) is the first central processing center for olfactory information connecting with higher areas in the brain, and this neuronal circuitry mediates a variety of odor-evoked behavioral responses. In the adult mammalian brain, continuous neurogenesis occurs in two restricted regions, the subventricular zone (SVZ) of the lateral ventricle and the hippocampal dentate gyrus. New neurons born in the SVZ migrate through the rostral migratory stream and are integrated into the ne...

  4. Comparison of rat olfactory mucosal responses to carcinogenic and non-carcinogenic chloracetanilides

    OpenAIRE

    Genter, M.B.; Warner, B.M.; Medvedovic, M.; Sartor, M.A.

    2009-01-01

    Alachlor and butachlor are chloracetanilide herbicides that induce olfactory tumors in rats, whereas propachlor does not. The mechanism by which alachlor induces tumors is distinct from many other nasal carcinogens, in that alachlor induces a gradual de-differentiation of the olfactory mucosa (OM) to a more respiratory-like epithelium, in contrast to other agents that induce cytotoxicity, followed by an aberrant regenerative response. We studied biochemical and genomic effects of these compou...

  5. A population of glomerular glutamatergic neurons controls sensory information transfer in the mouse olfactory bulb

    OpenAIRE

    Tatti, Roberta; Bhaukaurally, Khaleel; Gschwend, Olivier; Seal, Rebecca P.; Edwards, Robert H.; Rodriguez, Ivan; Carleton, Alan

    2014-01-01

    In sensory systems, peripheral organs convey sensory inputs to relay networks where information is shaped by local microcircuits before being transmitted to cortical areas. In the olfactory system, odorants evoke specific patterns of sensory neuron activity which are transmitted to output neurons in olfactory bulb glomeruli. How sensory information is transferred and shaped at this level remains still unclear. Here we employ mouse genetics, 2-photon microscopy, electrophysiology and optogenet...

  6. Hierarchical organization of long-range circuits in the olfactory cortices

    OpenAIRE

    Yang, Weiguo; Sun, Qian-Quan

    2015-01-01

    How sensory information is processed within olfactory cortices is unclear. Here, we examined long-range circuit wiring between different olfactory cortical regions of acute mouse brain slices using a channelrhodopsin-2 (ChR2)-based neuronal targeting approach. Our results provide detailed information regarding the synaptic properties of the reciprocal long-range monosynaptic glutamatergic projections (LRMGP) between and within anterior piriform cortex (aPC), posterior piriform cortex (pPC), a...

  7. Sexual activity increases the number of newborn cells in the accessory olfactory bulb of male rats

    OpenAIRE

    Portillo, Wendy; Unda, Nancy; Camacho, Francisco J.; Sánchez, María; Corona, Rebeca; Arzate, Dulce Ma.; Díaz, Néstor F.; Paredes, Raúl G.

    2012-01-01

    In rodents, sexual behavior depends on the adequate detection of sexually relevant stimuli. The olfactory bulb (OB) is a region of the adult mammalian brain undergoing constant cell renewal by continuous integration of new granular and periglomerular neurons in the accessory (AOB) and main (MOB) olfactory bulbs. The proliferation, migration, survival, maturation, and integration of these new cells to the OB depend on the stimulus that the subjects received. We have previously shown that 15 da...

  8. Sexual activity increases the number of newborn cells in the accessory olfactory bulb of male rats.

    OpenAIRE

    Wendy Portillo; Díaz, Néstor F.

    2012-01-01

    In rodents, sexual behavior depends on the adequate detection of sexually relevant stimuli. The olfactory bulb (OB) is a region of the adult mammalian brain undergoing constant cell renewal by continuous integration of new granular and periglomerular neurons in the accessory (AOB) and main (MOB) olfactory bulbs. The proliferation, migration, survival, maturation, and integration of these new cells to the OB depend on the stimulus that the subjects received. We have previously shown that 15 da...

  9. Involvement of right piriform cortex in olfactory familiarity judgments. : Familiarity judgment in olfaction

    OpenAIRE

    Plailly, Jane; Bensafi, Moustafa; Pachot-Clouard, Mathilde; Delon-Martin, Chantal; Kareken, David; Rouby, Catherine; Segebarth, Christoph; Royet, Jean,

    2005-01-01

    Previous studies have shown activation of right orbitofrontal cortex during judgments of odor familiarity. In the present study, we sought to extend our knowledge about the neural circuits involved in such a task by exploring the involvement of the right prefrontal areas and limbic/primary olfactory structures. Fourteen right-handed male subjects were tested using fMRI with a single functional run of two olfactory conditions (odor detection and familiarity judgments). Each condition included ...

  10. Pinpointing food sources: olfactory and anemotactic orientation in desert ants, Cataglyphis fortis.

    OpenAIRE

    Wolf, H.; Wehner, R

    2000-01-01

    Desert ants, Cataglyphis fortis, search for a repeatedly visited food source by employing a combined olfactory and anemotactic orientation strategy (in addition to their visually based path-integration scheme). This behaviour was investigated by video-tracking consecutive foraging trips of individually marked ants under a variety of experimental conditions, including manipulations of the olfactory and wind-detecting systems of the ants. If the wind blows from a constant direction, ants famili...

  11. Odorant responses of Xenopus laevis tadpole olfactory neurons: a comparison between preparations.

    OpenAIRE

    Manzini, Ivan; Peters, Florian; Schild, Detlev

    2002-01-01

    We used a slice preparation of the olfactory epithelium of Xenopus laevis tadpoles to record odorant responses of olfactory receptor neurons (ORNs) and compared these to odorant responses recorded in isolated ORNs. The maximum recording time in the slice was considerably longer than in isolated ORNs, which is essential when many odorants are to be tested. No odorant-induced responses could be obtained from isolated ORNs recorded in the on-cell mode, while recordings in the slice (on-cell and ...

  12. Baclofen blocks postsynaptic inhibition but not the effect of muscimol in the olfactory cortex.

    OpenAIRE

    Scholfield, C. N.

    1983-01-01

    1 The olfactory cortex slice preparation from the guinea-pig brain was used to study the effects of baclofen on inhibition using intracellular recording. Stimulation of the lateral olfactory tract activities sequentially excitatory and inhibitory pathways. Inhibition is manifest as a period of increased membrane conductance (termed postsynaptic inhibitory conductance, IPSC). 2 Bath application of baclofen (0.2-500 muM) reversibly blocked the IPSC. Baclofen also produced a secondary increase i...

  13. Of volatiles and peptides: in search for MHC-dependent olfactory signals in social communication

    OpenAIRE

    Overath, Peter; Sturm, Theo; Rammensee, Hans-Georg

    2014-01-01

    Genes of the major histocompatibility complex (MHC), which play a critical role in immune recognition, are considered to influence social behaviors in mice, fish, humans, and other vertebrates via olfactory cues. As studied most extensively in mice, the polymorphism of MHC class I genes is considered to bring about a specific scent signature, which is decoded by the olfactory system resulting in an individual-specific reaction such as mating. On the assumption that this signature resides in v...

  14. Continuous Spatial Representations in the Olfactory Bulb may Reflect Perceptual Categories

    OpenAIRE

    Benjamin Auffarth; Agustín Gutierrez-Galvez; Santiago Marco

    2011-01-01

    In sensory processing of odors, the olfactory bulb is an important relay station, where odor representations are noise-filtered, sharpened, and possibly re-organized. An organization by perceptual qualities has been found previously in the piriform cortex, however several recent studies indicate that the olfactory bulb code reflects behaviorally relevant dimensions spatially as well as at the population level. We apply a statistical analysis on 2-deoxyglucose images, taken over the entire bul...

  15. Olfactory-Triggered Panic Attacks Among Khmer Refugees: A Contextual Approach

    OpenAIRE

    Hinton, Devon; Pich, Vuth; Chhean, Dara; Pollack, Mark

    2004-01-01

    One hundred Khmer refugees attending a psychiatric clinic were surveyed to determine the prevalence of olfactory-triggered panic attacks as well as certain characteristics of the episodes, including trigger (i.e. type of odor), frequency, length, somatic symptoms, and the rate of associated flashbacks and catastrophic cognitions. Forty-five of the 100 patients had experienced an olfactory-triggered panic attack in the last month. Trauma associations and catastrophic cognitions (e.g. fears of ...

  16. A circadian clock in the olfactory bulb anticipates feeding during food anticipatory activity.

    Directory of Open Access Journals (Sweden)

    Nahum Nolasco

    Full Text Available Rabbit pups ingest food, in this case milk, once a day with circadian periodicity and are a natural model of food anticipatory activity. During nursing, several sensory systems receive information about properties of the food, one of them being the olfactory system, which has received little attention in relation to synchronization by food. In addition, the olfactory bulb has a circadian pacemaker that exhibits rhythms independently of the suprachiasmatic nucleus, but the biological functions of these rhythms are largely unknown. In the present contribution, we hypothesized that circadian suckling of milk synchronizes rhythms in the olfactory bulb. To this aim we explored by immunohistochemistry, rhythms of FOS and PER1 proteins, as indicators of activation and reporter of oscillations, respectively, through a complete 24-h cycle in periglomerular, mitral and granular cell layers of both the main and the accessory olfactory bulb. Subjects were 7-day-old rabbit pups scheduled to nurse during the night (02:00 h or day (10:00 h, and also fasted subjects, to explore the possible persistence of oscillations. In the three layers of the main olfactory bulb, FOS was high at time of nursing, then further increased 1.5 h afterward, and then decreased to increase again in advance of the next nursing bout. This pattern persisted, without the postprandial increase, in fasted subjects with a shift in subjects nursed at 02:00. PER1 was increased 2-8 h after nursing and this increase persisted in most cell layers, with a shift, in fasted subjects. In the accessory olfactory bulb we only observed a consistent pattern of FOS expression in the mitral cell layer of nursed subjects, similar to that of the main olfactory bulb. We conclude that the main olfactory bulb is synchronized during milk ingestion, but during fasting its oscillations perhaps are modulated by the suprachiasmatic nucleus, as proposed for rodents.

  17. Opposing Fgf and Bmp activities regulate the specification of olfactory sensory and respiratory epithelial cell fates

    OpenAIRE

    Maier, Esther; von Hofsten, Jonas; Nord, Hanna; Fernandes, Marie; Paek, Hunki; Hébert, Jean M.; Gunhaga, Lena

    2010-01-01

    The olfactory sensory epithelium and the respiratory epithelium are derived from the olfactory placode. However, the molecular mechanisms regulating the differential specification of the sensory and the respiratory epithelium have remained undefined. To address this issue, we first identified Msx1/2 and Id3 as markers for respiratory epithelial cells by performing quail chick transplantation studies. Next, we established chick explant and intact chick embryo assays of sensory/respiratory epit...

  18. The effects of exercise and diet on olfactory capability in detection dogs*

    OpenAIRE

    Angle, Craig T.; Wakshlag, Joseph J.; Gillette, Robert L.; Steury, Todd; Haney, Pamela; Barrett, Jay; Fisher, Terrence

    2014-01-01

    A previous work suggests that dietary fat may influence canine olfaction. The present study evaluated whether olfactory performance could be influenced by forms of dietary fat and exercise. Seventeen certified detection dogs were fed three different diets (high fat, low fat or high polyunsaturated fat) for 12 weeks. After 12 weeks, olfactory testing was performed using a scent wheel in an olfaction laboratory using three explosive materials. The dogs completed eight to twelve scent trials bef...

  19. Osterix is dispensable for the development of the mouse olfactory bulb.

    Science.gov (United States)

    Park, Ji-Soo; Park, Geon-Il; Kim, Jung-Eun

    2016-09-01

    Osterix (Osx) has been shown to be an osteoblast-specific transcription factor for bone formation. Recently, it has been reported that Osx is significantly expressed in the mouse olfactory bulb, proving that Osx may play a role in olfactory bulb development, as well as bone development. Here, we studied morphological differences and neuronal cell alterations in the olfactory bulb using an Osx gene-modified mouse model. Although Osx expression was reduced, morphological differences were not observed in the olfactory bulb of Osx heterozygous mice compared with that of wild-type mice. Immunofluorescence using the neuronal marker genes DCX, MAP2, NeuN, and GFAP showed neuronal cell alterations caused by Osx deficiency in the mitral cell layer (MCL) and granule cell layer (GCL) of the olfactory bulb at postnatal stage. The number, morphology, and expression patterns of immature neurons, mature neurons, and astrocytes were identical in both wild-type and Osx heterozygous mice. At the post-embryonic stage, the expression of neuronal markers DCX, Nestin, MAP2, and NeuN were examined in the MCL and GCL of the olfactory bulb in wild-type, Osx heterozygous, and Osx knockout embryos. Both DCX- and Nestin-positive immature neurons, and MAP2- and NeuN-positive mature neurons, revealed a similar expression pattern in all mouse types. These results indicated that olfactory bulb development was not significantly impaired in the absence of Osx. Further study may be necessary to explain the functional properties of the olfactory bulb caused by Osx deficiency. PMID:27449610

  20. Activity Regulates Functional Connectivity from the Vomeronasal Organ to the Accessory Olfactory Bulb

    OpenAIRE

    Hovis, Kenneth R.; Ramnath, Rohit; Dahlen, Jeffrey E.; Romanova, Anna L.; LaRocca, Greg; Bier, Mark E.; Urban, Nathaniel N.

    2012-01-01

    The mammalian accessory olfactory system is specialized for the detection of chemicals that identify kin and conspecifics. Vomeronasal sensory neurons (VSNs), residing in the vomeronasal organ, project axons to the accessory olfactory bulb (AOB) where they form synapses with principle neurons, known as mitral cells. The organization of this projection is quite precise and is believed to be essential for appropriate function of this system. However, how this precise connectivity is established...

  1. 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; Ngai, John

    2013-09-18

    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

  2. Cross-Fostering of Male Mice Subtly Affects Female Olfactory Preferences

    OpenAIRE

    Liu, Ying-Juan; Zhang, Yao-Hua; Li, Lai-Fu; Du, Rui-Qing; Zhang, Jin-Hua; Zhang, Jian-Xu

    2016-01-01

    The maternal environment has been shown to influence female olfactory preferences through early chemosensory experience. However, little is known about the influence of the maternal environment on chemosignals. In this study, we used two inbred mouse strains, C57BL/6 (C57) and BALB/c (BALB), and explored whether adoption could alter male chemosignals and thus influence female olfactory preferences. In Experiment 1, C57 pups were placed with BALB dams. Adult BALB females then served as the sub...

  3. Modulation of olfactory sensitivity and glucose-sensing by the feeding state in obese Zucker rats

    Science.gov (United States)

    Aimé, Pascaline; Palouzier-Paulignan, Brigitte; Salem, Rita; Al Koborssy, Dolly; Garcia, Samuel; Duchamp, Claude; Romestaing, Caroline; Julliard, A. Karyn

    2014-01-01

    The Zucker fa/fa rat has been widely used as an animal model to study obesity, since it recapitulates most of its behavioral and metabolic dysfunctions, such as hyperphagia, hyperglycemia and insulin resistance. Although it is well established that olfaction is under nutritional and hormonal influences, little is known about the impact of metabolic dysfunctions on olfactory performances and glucose-sensing in the olfactory system of the obese Zucker rat. In the present study, using a behavioral paradigm based on a conditioned olfactory aversion, we have shown that both obese and lean Zucker rats have a better olfactory sensitivity when they are fasted than when they are satiated. Interestingly, the obese Zucker rats displayed a higher olfactory sensitivity than their lean controls. By investigating the molecular mechanisms involved in glucose-sensing in the olfactory system, we demonstrated that sodium-coupled glucose transporters 1 (SGLT1) and insulin dependent glucose transporters 4 (GLUT4) are both expressed in the olfactory bulb (OB). By comparing the expression of GLUT4 and SGLT1 in OB of obese and lean Zucker rats, we found that only SGLT1 is regulated in genotype-dependent manner. Next, we used glucose oxidase biosensors to simultaneously measure in vivo the extracellular fluid glucose concentrations ([Gluc]ECF) in the OB and the cortex. Under metabolic steady state, we have determined that the OB contained twice the amount of glucose found in the cortex. In both regions, the [Gluc]ECF was 2 fold higher in obese rats compared to their lean controls. Under induced dynamic glycemia conditions, insulin injection produced a greater decrease of [Gluc]ECF in the OB than in the cortex. Glucose injection did not affect OB [Gluc]ECF in Zucker fa/fa rats. In conclusion, these results emphasize the importance of glucose for the OB network function and provide strong arguments towards establishing the OB glucose-sensing as a key factor for sensory olfactory processing

  4. Modulation of olfactory sensitivity and glucose sensing by the feeding state in obese Zucker rats.

    Directory of Open Access Journals (Sweden)

    Pascaline eAimé

    2014-09-01

    Full Text Available The Zucker fa/fa rat has been widely used as an animal model to study obesity, since it recapitulates most of its behavioral and metabolic dysfunctions, such as hyperphagia, hyperglycemia and insulin resistance. Although it is well established that olfaction is under nutritional and hormonal influences, little is known about the impact of metabolic dysfunctions on olfactory performances and glucose-sensing in the olfactory system of the obese Zucker rat. In the present study, using a behavioral paradigm based on a conditioned olfactory aversion, we have shown that both obese and lean Zucker rats have a better olfactory sensitivity when they are fasted than when they are satiated. Interestingly, the obese Zucker rats displayed a higher olfactory sensitivity than their lean controls. By investigating the molecular mechanisms involved in glucose-sensing in the olfactory system, we demonstrated that sodium-coupled glucose transporters 1 (SGLT1 and insulin dependent glucose transporters 4 (GLUT4 are both expressed in the olfactory bulb (OB. By comparing the expression of GLUT4 and SGLT1 in OB of obese and lean Zucker rats, we found that only SGLT1 is regulated in genotype-dependent manner. Next, we used glucose oxidase biosensors to simultaneously measure in vivo the extracellular fluid glucose concentrations ([Gluc]ECF in the OB and the cortex. Under metabolic steady state, we have determined that the OB contained twice the amount of glucose found in the cortex. In both regions, the [Gluc]ECF was 2 fold higher in obese rats compared to their lean controls. Under induced dynamic glycemia conditions, insulin injection produced a greater decrease of [Gluc]ECF in the OB than in the cortex. Glucose injection did not affect OB [Gluc]ECF in Zucker fa/fa rats. In conclusion, these results emphasize the importance of glucose for the OB network function and provide strong arguments towards establishing the OB glucose-sensing as a key factor for sensory

  5. Olfactory and gustatory hallucinations presenting as partial status epilepticus because of glioblastoma multiforme.

    Science.gov (United States)

    Capampangan, Dan J; Hoerth, Matthew T; Drazkowski, Joseph F; Lipinski, Christopher A

    2010-10-01

    Olfactory and gustatory hallucinations are not often encountered in the acute care setting but may represent the subtle presenting features of a significant underlying disease process. We describe a patient whose most striking presenting symptoms were of olfactory and gustatory hallucinations and in whom the diagnosis and treatment of a new brain tumor and partial status epilepticus occurred entirely in the emergency department. The lesion was subsequently identified as glioblastoma multiforme involving the hippocampus and amygdala. PMID:20303620

  6. Scaling of olfactory antennae of the terrestrial hermit crabs Coenobita rugosus and Coenobita perlatus during ontogeny

    OpenAIRE

    Waldrop, Lindsay D.; Bantay, Roxanne M.; Nguyen, Quang V

    2014-01-01

    Although many lineages of terrestrial crustaceans have poor olfactory capabilities, crabs in the family Coenobitidae, including the terrestrial hermit crabs in the genus Coenobita, are able to locate food and water using olfactory antennae (antennules) to capture odors from the surrounding air. Terrestrial hermit crabs begin their lives as small marine larvae and must find a suitable place to undergo metamorphosis into a juvenile form, which initiates their transition to land. Juveniles incre...

  7. Axonal transport of cadmium in the olfactory nerve of the pike

    International Nuclear Information System (INIS)

    109Cd2+ was applied in the olfactory chambers of pikes (Esox lucius) and the dynamics of the axoplasmic flow of the metal was determined in the olfactory nerves by gamma spectrometry and autoradiography. The results showed that the 109Cd2+ is transported at a constant rate along the olfactory nerves. The profile of the 109Cd2+ in the nerves showed a wave front of transported metal followed by a saddle region. When the nasal chambers were washed 2 hr after application of the 109Cd2+ well-defined transport peaks for the metal were seen in the olfactory axons. The maximal velocity for the transport of 109Cd2+, which corresponds to the movement of the wave front, was 2.38±0.10 mm/hr (mean±S.E.) at the experimental temperature (10 deg. C). The average velocity for the transport of the 109Cd2+, which corresponds to the peak apex movement of the wave, was 2.18±0.05 mm/hr (mean ±S.E.) at 10 deg. C. The tranported 109Cd2+ was strongly accumulated in the anterior parts of the olfactory bulbs, whereas in other brain areas the levels of the metal remained low. Autoradiography of a pike exposed to 109Cd2+ via the water showed a strong labelling in the receptor-cell-containing olfactory rosettes, whereas other structures in the olfactory chambers were only weakly labelled. The accumulation and axonal transport in the olfactory neurons may be noxious and constitute an important component in the toxicology of cadmium in fish, and this may apply also to some other heavy metals. (author)

  8. Diversity among principal and GABAergic neurons of the anterior olfactory nucleus

    OpenAIRE

    KAY, RACHEL B.; Brunjes, Peter C

    2014-01-01

    Understanding the cellular components of neural circuits is an essential step in discerning regional function. The anterior olfactory nucleus (AON) is reciprocally connected to both the ipsi- and contralateral olfactory bulb (OB) and piriform cortex (PC), and, as a result, can broadly influence the central processing of odor information. While both the AON and PC are simple cortical structures, the regions differ in many ways including their general organization, internal wiring and synaptic ...

  9. Neuronal pattern separation in the olfactory bulb improves odor discrimination learning

    OpenAIRE

    Gschwend, Olivier; Abraham, Nixon; Lagier, Samuel; Begnaud, Frédéric; Rodriguez, Ivan; Carleton, Alan

    2015-01-01

    Neuronal pattern separation is thought to enable the brain to disambiguate sensory stimuli with overlapping features thereby extracting valuable information. In the olfactory system, it remains unknown whether pattern separation acts as a driving force for sensory discrimination and the learning thereof. Here we show that overlapping odor-evoked input patterns to the mouse olfactory bulb (OB) are dynamically reformatted in the network at the timescale of a single breath, giving rise to separa...

  10. Remyelination of the Corpus Callosum by Olfactory Ensheathing Cell in an Experimental Model of Multiple Sclerosis

    OpenAIRE

    Mohammad Azimi Alamouti; Mehrdad Bakhtiyari; Fatemeh Moradi; Tahmineh Mokhtari; Azim Hedayatpour; Fariba Zafari; Mohammad Barbarestani

    2015-01-01

    Multiple Sclerosis (MS) causes loss of the myelin sheath, which leads to loss of neurons. Regeneration of myelin sheath stimulates axon regeneration and neurons’ survival. In this study, olfactory ensheathing cell (OEC) transplantation is investigated to restore myelin sheath in an experimental model of MS in male mice.OECs were isolated from the olfactory mucosa of seven-day-old infant rats and cultured. Then, cells were evaluated and approved by flow cytometry by p75 and GFAP markers. A tot...

  11. Olfactory Receptor Multigene Family in Vertebrates: From the Viewpoint of Evolutionary Genomics

    OpenAIRE

    Niimura, Yoshihito

    2012-01-01

    Olfaction is essential for the survival of animals. Diverse odor molecules in the environment are detected by the olfactory receptors (ORs) in the olfactory epithelium of the nasal cavity. There are ~400 and ~1,000 OR genes in the human and mouse genomes, respectively, forming the largest multigene family in mammals. The relationships between ORs and odorants are multiple-to-multiple, which allows for discriminating almost unlimited number of different odorants by a combination of ORs. Howeve...

  12. Plastic food packaging and health

    Directory of Open Access Journals (Sweden)

    Raika Durusoy

    2011-02-01

    Full Text Available Plastics have a wide usage in our daily lives. One of their uses is for food packaging and food containers. The aim of this review is to introduce different types of chemicals that can leach from food packaging plastics into foods and cause human exposure and to mention their effects on health. The types of plastics were reviewed under the 13 headings in Turkish Codex Alimentarius and plastics recycling symbols were provided to enable the recognition of the type of plastic when applicable. Chemicals used during the production and that can cause health risks are investigated under the heading of the relevant type of plastic. The most important chemicals from plastic food packaging that can cause toxicity are styrene, 1,3-butadiene, melamine, formaldehyde, acrylamide, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, vinyl chloride and bisphenol A. These chemicals have endocrine disrupting, carcinogenic and/or development disrupting effects. These chemicals may leach into foods depending on the chemical properties of the plastic or food, temperature during packaging, processing and storage, exposure to UV and duration of storage. Contact with fatty/oily or acidic foods, heating of the food inside the container, or drinking hot drinks from plastic cups, use of old and scratched plastics and some detergents increase the risk of leaching. The use of plastic containers and packaging for food and beveradges should be avoided whenever possible and when necessary, less harmful types of plastic should be preferred. [TAF Prev Med Bull 2011; 10(1.000: 87-96

  13. PLASMA GASIFICATION OF WASTE PLASTICS

    OpenAIRE

    Tadeusz Mączka; Ewa Śliwka; Mateusz Wnukowski

    2013-01-01

    The article presents the process of obtaining liquid fuels and fuel gas in the process of plasma processing of organic materials, including waste plastics. The concept of plasma pyrolysis of plastics was presented and on its basis a prototype installation was developed. The article describes a general rule of operating the installation and its elements in the process and basic operation parameters determined during its start-up. Initial results of processing plastics and the directions furthe...

  14. Imaging brain plasticity after trauma

    OpenAIRE

    Kou, Zhifeng; Iraji, Armin

    2014-01-01

    The brain is highly plastic after stroke or epilepsy; however, there is a paucity of brain plasticity investigation after traumatic brain injury (TBI). This mini review summarizes the most recent evidence of brain plasticity in human TBI patients from the perspective of advanced magnetic resonance imaging. Similar to other forms of acquired brain injury, TBI patients also demonstrated both structural reorganization as well as functional compensation by the recruitment of other brain regions. ...

  15. Some Misconceptions About Plastic Degradation

    OpenAIRE

    Raouf, Mohamed Imad N. Raouf

    1999-01-01

    In consistence with the importance of implementing best utilization of human resources towards maintaining suitable healthy environment for our next generations, concepts and fundamentals upon which most researches on degradation of plastics are based, as a solution of solid waste reduction, will be discussed. Proper understanding of plastic figures would better utilize human efforts toward useful tasks to control solid waste. Unfortunately, when plastics are made more degradable, they becom...

  16. Surface coating of plastics

    International Nuclear Information System (INIS)

    Electron beam hardening technology has been used mainly for the cross-linking reaction of plastic materials, but recently attention has been paid to the easiness of handling due to the reduction of equipment size and as the countermeasures for preventing atmospheric pollution caused by solvent type paints, Particularly the authors notices the excellent surface properties of electron beam-hardened coatings themselves, and advanced the research and development as one means to give functions to plastic films. In this paper, the transcription foil films having hardness and blur-preventing films are reported. The transcription process for the transcription foils on which hard coating is applied beforehand is shown. The electron beam hardening hard coating was provided next to a supporting film, and its material was polymer or oligomer/polyfunctional monomer/additive. As a primer layer, acrylic polymer was used. The procedure of making transcription foils is explained, and it is important to form uniform, smooth films. If the formation of water drops on surfaces can be prevented, blur does not arise. By heightening the hydrophilicity of material surfaces with electron beam, it may be done. By the selection of the irradiation amount of electron beam and materials, the balance must be maintained. (K.I.)

  17. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2010-07-15

    The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  18. Americium behaviour in plastic vessels

    International Nuclear Information System (INIS)

    The adsorption of 241Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of 241Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of 241Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  19. Brief embryonic cadmium exposure induces a stress response and cell death in the developing olfactory system followed by long-term olfactory deficits in juvenile zebrafish

    International Nuclear Information System (INIS)

    The toxic effects of cadmium and other metals have been well established. A primary target of these metals is known to be the olfactory system, and fish exposed to a number of different waterborne metals display deficiencies in olfaction. Importantly, exposure over embryonic/larval development periods can cause deficits in chemosensory function in juvenile fish, but the specific cell types affected are unknown. We have previously characterized a transgenic zebrafish strain expressing the green fluorescent protein (eGFP) gene linked to the hsp70 gene promoter, and shown it to be a useful tool for examining cell-specific toxicity in living embryos and larvae. Here we show that the hsp70/eGFP transgene is strongly and specifically upregulated within the olfactory sensory neurons (OSNs) of transgenic zebrafish larvae following a brief 3-h exposure to water-borne cadmium. This molecular response was closely correlated to an endpoint for tissue damage within the olfactory placode, namely cell death. Furthermore, cadmium-induced olfactory cytotoxicity in zebrafish larvae gives rise to more permanent effects. Juvenile zebrafish briefly exposed to cadmium during early larval development display deficits in olfactory-dependent predator avoidance behaviors 4-6 weeks after a return to clean water. Lateral line neuromasts of exposed zebrafish larvae also activate both the endogenous hsp70 gene and the hsp70/eGFP transgene. The data reveal that even a very brief exposure period that gives rise to cell death within the developing olfactory placode results in long-term deficits in olfaction, and that hsp70/eGFP may serve as an effective indicator of sublethal cadmium exposure in sensory cells

  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. PMID:27059760