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Sample records for appetitive olfactory learning

  1. Appetitive associative olfactory learning in Drosophila larvae.

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    Apostolopoulou, Anthi A; Widmann, Annekathrin; Rohwedder, Astrid; Pfitzenmaier, Johanna E; Thum, Andreas S

    2013-02-18

    In the following we describe the methodological details of appetitive associative olfactory learning in Drosophila larvae. The setup, in combination with genetic interference, provides a handle to analyze the neuronal and molecular fundamentals of specifically associative learning in a simple larval brain. Organisms can use past experience to adjust present behavior. Such acquisition of behavioral potential can be defined as learning, and the physical bases of these potentials as memory traces. Neuroscientists try to understand how these processes are organized in terms of molecular and neuronal changes in the brain by using a variety of methods in model organisms ranging from insects to vertebrates. For such endeavors it is helpful to use model systems that are simple and experimentally accessible. The Drosophila larva has turned out to satisfy these demands based on the availability of robust behavioral assays, the existence of a variety of transgenic techniques and the elementary organization of the nervous system comprising only about 10,000 neurons (albeit with some concessions: cognitive limitations, few behavioral options, and richness of experience questionable). Drosophila larvae can form associations between odors and appetitive gustatory reinforcement like sugar. In a standard assay, established in the lab of B. Gerber, animals receive a two-odor reciprocal training: A first group of larvae is exposed to an odor A together with a gustatory reinforcer (sugar reward) and is subsequently exposed to an odor B without reinforcement. Meanwhile a second group of larvae receives reciprocal training while experiencing odor A without reinforcement and subsequently being exposed to odor B with reinforcement (sugar reward). In the following both groups are tested for their preference between the two odors. Relatively higher preferences for the rewarded odor reflect associative learning--presented as a performance index (PI). The conclusion regarding the associative

  2. Appetitive Olfactory Learning and Long-Term Associative Memory in Caenorhabditis elegans

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    Ichiro N. Maruyama

    2017-05-01

    Full Text Available Because of the relative simplicity of its nervous system, Caenorhabditis elegans is a useful model organism to study learning and memory at cellular and molecular levels. For appetitive conditioning in C. elegans, food has exclusively been used as an unconditioned stimulus (US. It may be difficult to analyze neuronal circuits for associative memory since food is a multimodal combination of olfactory, gustatory, and mechanical stimuli. Here, we report classical appetitive conditioning and associative memory in C. elegans, using 1-nonanol as a conditioned stimulus (CS, and potassium chloride (KCl as a US. Before conditioning, C. elegans innately avoided 1-nonanol, an aversive olfactory stimulus, and was attracted by KCl, an appetitive gustatory stimulus, on assay agar plates. Both massed training without an intertrial interval (ITI and spaced training with a 10-min ITI induced significant levels of memory of association regarding the two chemicals. Memory induced by massed training decayed within 6 h, while that induced by spaced training was retained for more than 6 h. Animals treated with inhibitors of transcription or translation formed the memory induced by spaced training less efficiently than untreated animals, whereas the memory induced by massed training was not significantly affected by such treatments. By definition, therefore, memories induced by massed training and spaced training are classified as short-term memory (STM and long-term memory (LTM, respectively. When animals conditioned by spaced training were exposed to 1-nonanol alone, their learning index was lower than that of untreated animals, suggesting that extinction learning occurs in C. elegans. In support of these results, C. elegans mutants defective in nmr-1, encoding an NMDA receptor subunit, formed both STM and LTM less efficiently than wild-type animals, while mutations in crh-1, encoding a ubiquitous transcription factor CREB required for memory consolidation, affected

  3. An alarm pheromone modulates appetitive olfactory learning in the honeybee (Apis mellifera

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    Elodie Urlacher

    2010-08-01

    Full Text Available In honeybees, associative learning is embedded in a social context as bees possess a highly complex social organization in which communication among individuals is mediated by dance behavior informing about food sources, and by a high variety of pheromones that maintain the social links between individuals of a hive. Proboscis extension response (PER conditioning is a case of appetitive learning, in which harnessed bees learn to associate odor stimuli with sucrose reward in the laboratory. Despite its recurrent use as a tool for uncovering the behavioral, cellular and molecular bases underlying associative learning, the question of whether social signals (pheromones affect appetitive learning has not been addressed in this experimental framework. This situation contrasts with reports underlining that foraging activity of bees is modulated by alarm pheromones released in the presence of a potential danger. Here, we show that appetitive learning is impaired by the sting alarm pheromone (SAP which, when released by guards, recruits foragers to defend the hive. This effect is mimicked by the main component of SAP, isopentyl acetate (IPA, is dose-dependent and lasts up to 24h. Learning impairment is specific to alarm signal exposure and is independent of the odorant used for conditioning. Our results suggest that learning impairment may be a response to the biological significance of SAP as an alarm signal, which would detract bees from responding to any appetitive stimuli in a situation in which such responses would be of secondary importance.

  4. An alarm pheromone modulates appetitive olfactory learning in the honeybee (apis mellifera).

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    Urlacher, Elodie; Francés, Bernard; Giurfa, Martin; Devaud, Jean-Marc

    2010-01-01

    In honeybees, associative learning is embedded in a social context as bees possess a highly complex social organization in which communication among individuals is mediated by dance behavior informing about food sources, and by a high variety of pheromones that maintain the social links between individuals of a hive. Proboscis extension response conditioning is a case of appetitive learning, in which harnessed bees learn to associate odor stimuli with sucrose reward in the laboratory. Despite its recurrent use as a tool for uncovering the behavioral, cellular, and molecular bases underlying associative learning, the question of whether social signals (pheromones) affect appetitive learning has not been addressed in this experimental framework. This situation contrasts with reports underlining that foraging activity of bees is modulated by alarm pheromones released in the presence of a potential danger. Here, we show that appetitive learning is impaired by the sting alarm pheromone (SAP) which, when released by guards, recruits foragers to defend the hive. This effect is mimicked by the main component of SAP, isopentyl acetate, is dose-dependent and lasts up to 24 h. Learning impairment is specific to alarm signal exposure and is independent of the odorant used for conditioning. Our results suggest that learning impairment may be a response to the biological significance of SAP as an alarm signal, which would detract bees from responding to any appetitive stimuli in a situation in which such responses would be of secondary importance.

  5. Learning the way to blood: first evidence of dual olfactory conditioning in a blood-sucking insect, Rhodnius prolixus. I. Appetitive learning.

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    Vinauger, Clément; Buratti, Laura; Lazzari, Claudio R

    2011-09-15

    It has been largely assumed that the individual experience of insects that are disease vectors might not only contribute to animal fitness, but also have an important influence on parasite transmission. Nevertheless, despite the invested efforts in testing the capacity to learn and remember information in blood-sucking insects, only little conclusive information has been obtained to date. Adapting a classical conditioning approach to our haematophagous model, we trained larvae of Rhodnius prolixus to associate L-lactic-acid, an odour perceived by these bugs but behaviourally neutral when presented alone, with food (i.e. positive reinforcement). Naive bugs--those exposed either to a conditioned stimulus (CS, L-lactic acid), unconditioned stimulus (US, heat) and reward (blood) alone or CS, US and reward in the absence of contingency--remained indifferent to the presence of an air stream loaded with L-lactic acid when tested in an olfactometer (random orientation), whereas the groups previously exposed to the contingency CS-US-reward (blood) were significantly attracted by L-lactic-acid. In a companion paper, the opposite, i.e. repellence, was induced in bugs exposed to the contingency of the same odour with a negative reinforcement. This constitutes the first evidence of olfactory conditioning in triatomine bugs, vectors of Chagas disease, and one of the few substantiations available to date of olfactory conditioning in haematophagous insects.

  6. Acetylcholine and Olfactory Perceptual Learning

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

    2004-01-01

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

  7. Appetitive but Not Aversive Olfactory Conditioning Modifies Antennal Movements in Honeybees

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    Cholé, Hanna; Junca, Pierre; Sandoz, Jean-Christophe

    2015-01-01

    In honeybees, two olfactory conditioning protocols allow the study of appetitive and aversive Pavlovian associations. Appetitive conditioning of the proboscis extension response (PER) involves associating an odor, the conditioned stimulus (CS) with a sucrose solution, the unconditioned stimulus (US). Conversely, aversive conditioning of the sting…

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

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    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.

  9. Properties and mechanisms of olfactory learning and memory.

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    Tong, Michelle T; Peace, Shane T; Cleland, Thomas A

    2014-01-01

    Memories are dynamic physical phenomena with psychometric forms as well as characteristic timescales. Most of our understanding of the cellular mechanisms underlying the neurophysiology of memory, however, derives from one-trial learning paradigms that, while powerful, do not fully embody the gradual, representational, and statistical aspects of cumulative learning. The early olfactory system-particularly olfactory bulb-comprises a reasonably well-understood and experimentally accessible neuronal network with intrinsic plasticity that underlies both one-trial (adult aversive, neonatal) and cumulative (adult appetitive) odor learning. These olfactory circuits employ many of the same molecular and structural mechanisms of memory as, for example, hippocampal circuits following inhibitory avoidance conditioning, but the temporal sequences of post-conditioning molecular events are likely to differ owing to the need to incorporate new information from ongoing learning events into the evolving memory trace. Moreover, the shapes of acquired odor representations, and their gradual transformation over the course of cumulative learning, also can be directly measured, adding an additional representational dimension to the traditional metrics of memory strength and persistence. In this review, we describe some established molecular and structural mechanisms of memory with a focus on the timecourses of post-conditioning molecular processes. We describe the properties of odor learning intrinsic to the olfactory bulb and review the utility of the olfactory system of adult rodents as a memory system in which to study the cellular mechanisms of cumulative learning.

  10. Properties and mechanisms of olfactory learning and memory

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    Michelle T Tong

    2014-07-01

    Full Text Available Memories are dynamic physical phenomena with psychometric forms as well as characteristic timescales. Most of our understanding of the cellular mechanisms underlying the neurophysiology of memory, however, derives from one-trial learning paradigms that, while powerful, do not fully embody the gradual, representational, and statistical aspects of cumulative learning. The early olfactory system -- particularly olfactory bulb -- comprises a reasonably well-understood and experimentally accessible neuronal network with intrinsic plasticity that underlies both one-trial (adult aversive, neonatal and cumulative (adult appetitive odor learning. These olfactory circuits employ many of the same molecular and structural mechanisms of memory as, for example, hippocampal circuits following inhibitory avoidance conditioning, but the temporal sequences of post-conditioning molecular events are likely to differ owing to the need to incorporate new information from ongoing learning events into the evolving memory trace. Moreover, the shapes of acquired odor representations, and their gradual transformation over the course of cumulative learning, also can be directly measured, adding an additional representational dimension to the traditional metrics of memory strength and persistence. In this review, we describe some established molecular and structural mechanisms of memory with a focus on the timecourses of post-conditioning molecular processes. We describe the properties of odor learning intrinsic to the olfactory bulb and review the utility of the olfactory system of adult rodents as a memory system in which to study the cellular mechanisms of cumulative learning.

  11. Multiple memory traces for olfactory reward learning in Drosophila.

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    Thum, Andreas S; Jenett, Arnim; Ito, Kei; Heisenberg, Martin; Tanimoto, Hiromu

    2007-10-10

    Physical traces underlying simple memories can be confined to a single group of cells in the brain. In the fly Drosophila melanogaster, the Kenyon cells of the mushroom bodies house traces for both appetitive and aversive odor memories. The adenylate cyclase protein, Rutabaga, has been shown to mediate both traces. Here, we show that, for appetitive learning, another group of cells can additionally accommodate a Rutabaga-dependent memory trace. Localized expression of rutabaga in either projection neurons, the first-order olfactory interneurons, or in Kenyon cells, the second-order interneurons, is sufficient for rescuing the mutant defect in appetitive short-term memory. Thus, appetitive learning may induce multiple memory traces in the first- and second-order olfactory interneurons using the same plasticity mechanism. In contrast, aversive odor memory of rutabaga is rescued selectively in the Kenyon cells, but not in the projection neurons. This difference in the organization of memory traces is consistent with the internal representation of reward and punishment.

  12. Electric shock-induced associative olfactory learning in Drosophila larvae.

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    Pauls, Dennis; Pfitzenmaier, Johanna E R; Krebs-Wheaton, Rebecca; Selcho, Mareike; Stocker, Reinhard F; Thum, Andreas S

    2010-05-01

    Associative plasticity is a basic essential attribute of nervous systems. As shown by numerous reports, Drosophila is able to establish simple forms of appetitive and aversive olfactory associations at both larval and adult stages. Whereas most adult studies on aversive learning employed electric shock as a negative reinforcer, larval paradigms essentially utilized gustatory stimuli to create negative associations, a discrepancy that limits the comparison of data. To overcome this drawback, we critically revisited larval odor-electric shock conditioning. First, we show that lithium chloride (LiCl), which was used in all previous larval electric shock paradigms, is not required per se in larval odor-electric shock learning. This is of considerable practical advantage because beside its peculiar effects LiCl is attractive to larvae at low concentration that renders comparative learning studies on genetically manipulated larvae complicated. Second, we confirm that in both a 2-odor reciprocal and a 1-odor nonreciprocal conditioning regimen, larvae are able to associate an odor with electric shock. In the latter experiments, initial learning scores reach an asymptote after 5 training trials, and aversive memory is still detectable after 60 min. Our experiments provide a comprehensive basis for future comparisons of larval olfactory conditioning reinforced by different modalities, for studies aimed at analyzing odor-electric shock learning in the larva and the adult, and for investigations of the cellular and molecular substrate of aversive olfactory learning in the simple Drosophila model.

  13. 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

  14. Olfactory bulb encoding during learning under anesthesia

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    Nicol, Alister U.; Sanchez-Andrade, Gabriela; Collado, Paloma; Segonds-Pichon, Anne; Kendrick, Keith M.

    2014-01-01

    Neural plasticity changes within the olfactory bulb are important for olfactory learning, although how neural encoding changes support new associations with specific odors and whether they can be investigated under anesthesia, 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 odor smelled on the breath of a demonstrator animal occurs under isofluorane anesthesia. Furthermore, subsequent exposure to this cued odor under anesthesia promotes the same pattern of increased release of glutamate and gamma-aminobutyric acid (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 anesthesia before, during and after a novel scented food odor was paired with carbon disulfide. Results showed significant increases in overall firing frequency to the cued-odor during and after learning and decreases in response to an uncued odor. 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 odors prior to learning were either excited or inhibited afterwards. With the uncued odor 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 anesthesia promotes extensive, but spatially distinct, changes in mitral cell networks to both cued and uncued odors as well as in evoked glutamate and GABA

  15. Effects of Caffeine on Olfactory Learning in Crickets.

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    Sugimachi, Seigo; Matsumoto, Yukihisa; Mizunami, Makoto; Okada, Jiro

    2016-10-01

    Caffeine is a plant-derived alkaloid that is generally known as a central nervous system (CNS) stimulant. In order to examine the effects of caffeine on higher CNS functions in insects, we used an appetitive olfactory learning paradigm for the cricket Gryllus bimaculatus. Crickets can form significant long-term memories (LTMs) after repetitive training sessions, during which they associate a conditioned stimulus (CS: odor) with an unconditioned stimulus (US: reward). Administration of hemolymphal injections of caffeine established LTM after only single-trial conditioning over a wide range of caffeine dosages (1.6 µµg/kg to 39 mg/kg). We investigated the physiological mechanisms underlying this enhancement of olfactory learning performance pharmacologically, focusing on three major physiological roles of caffeine: 1) inhibition of phosphodiesterase (PDE), 2) agonism of ryanodine receptors, and 3) antagonism of adenosine receptors. Application of drugs relevant to these actions resulted in significant effects on LTM formation. These results suggest that externally applied caffeine enhances LTM formation in insect olfactory learning via multiple cellular mechanisms.

  16. Differential Recruitment of Distinct Amygdalar Nuclei across Appetitive Associative Learning

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    Cole, Sindy; Powell, Daniel J.; Petrovich, Gorica D.

    2013-01-01

    The amygdala is important for reward-associated learning, but how distinct cell groups within this heterogeneous structure are recruited during appetitive learning is unclear. Here we used Fos induction to map the functional amygdalar circuitry recruited during early and late training sessions of Pavlovian appetitive conditioning. We found that a…

  17. Parallel encoding of sensory history and behavioral preference during Caenorhabditis elegans olfactory learning

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    Cho, Christine E; Brueggemann, Chantal; L'Etoile, Noelle D; Bargmann, Cornelia I

    2016-01-01

    Sensory experience modifies behavior through both associative and non-associative learning. In Caenorhabditis elegans, pairing odor with food deprivation results in aversive olfactory learning, and pairing odor with food results in appetitive learning. Aversive learning requires nuclear translocation of the cGMP-dependent protein kinase EGL-4 in AWC olfactory neurons and an insulin signal from AIA interneurons. Here we show that the activity of neurons including AIA is acutely required during aversive, but not appetitive, learning. The AIA circuit and AGE-1, an insulin-regulated PI3 kinase, signal to AWC to drive nuclear enrichment of EGL-4 during conditioning. Odor exposure shifts the AWC dynamic range to higher odor concentrations regardless of food pairing or the AIA circuit, whereas AWC coupling to motor circuits is oppositely regulated by aversive and appetitive learning. These results suggest that non-associative sensory adaptation in AWC encodes odor history, while associative behavioral preference is encoded by altered AWC synaptic activity. DOI: http://dx.doi.org/10.7554/eLife.14000.001 PMID:27383131

  18. A Molecular Dissociation between Cued and Contextual Appetitive Learning

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    Kheirbek, Mazen A.; Beeler, Jeff A.; Chi, Wanhao; Ishikawa, Yoshihiro; Zhuang, Xiaoxi

    2010-01-01

    In appetitive Pavlovian learning, animals learn to associate discrete cues or environmental contexts with rewarding outcomes, and these cues and/or contexts can potentiate an ongoing instrumental response for reward. Although anatomical substrates underlying cued and contextual learning have been proposed, it remains unknown whether specific…

  19. A Molecular Dissociation between Cued and Contextual Appetitive Learning

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    Kheirbek, Mazen A.; Beeler, Jeff A.; Chi, Wanhao; Ishikawa, Yoshihiro; Zhuang, Xiaoxi

    2010-01-01

    In appetitive Pavlovian learning, animals learn to associate discrete cues or environmental contexts with rewarding outcomes, and these cues and/or contexts can potentiate an ongoing instrumental response for reward. Although anatomical substrates underlying cued and contextual learning have been proposed, it remains unknown whether specific…

  20. Multiple reversal olfactory learning in honeybees

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    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.  

  1. Honey Bees Modulate Their Olfactory Learning in the Presence of Hornet Predators and Alarm Component.

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    Zhengwei Wang

    Full Text Available In Southeast Asia the native honey bee species Apis cerana is often attacked by hornets (Vespa velutina, mainly in the period from April to November. During the co-evolution of these two species honey bees have developed several strategies to defend themselves such as learning the odors of hornets and releasing alarm components to inform other mates. However, so far little is known about whether and how honey bees modulate their olfactory learning in the presence of the hornet predator and alarm components of honey bee itself. In the present study, we test for associative olfactory learning of A. cerana in the presence of predator odors, the alarm pheromone component isopentyl acetate (IPA, or a floral odor (hexanal as a control. The results show that bees can detect live hornet odors, that there is almost no association between the innately aversive hornet odor and the appetitive stimulus sucrose, and that IPA is less well associated with an appetitive stimulus when compared with a floral odor. In order to imitate natural conditions, e.g. when bees are foraging on flowers and a predator shows up, or alarm pheromone is released by a captured mate, we tested combinations of the hornet odor and floral odor, or IPA and floral odor. Both of these combinations led to reduced learning scores. This study aims to contribute to a better understanding of the prey-predator system between A. cerana and V. velutina.

  2. Altered motivation masks appetitive learning potential of obese mice

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    Mazen R. Harb

    2014-10-01

    Full Text Available Eating depends strongly on learning processes which, in turn, depend on motivation. Conditioned learning, where individuals associate environmental cues with receipt of a reward, forms an important part of hedonic mechanisms; the latter contribute to the development of human overweight and obesity by driving excessive eating in what may become a vicious cycle. Although mice are commonly used to explore the regulation of human appetite, it is not known whether their conditioned learning of food rewards varies as a function of body mass. To address this, groups of adult male mice of differing body weights were tested two appetitive conditioning paradigms (pavlovian and operant as well as in food retrieval and hedonic preference tests in an attempt to dissect the respective roles of learning/motivation and energy state in the regulation of feeding behavior. We found that i the rate of pavlovian conditioning to an appetitive reward develops as an inverse function of body weight; ii higher body weight associates with increased latency to collect food reward; and iii mice with lower body weights are more motivated to work for a food reward, as compared to animals with higher body weights. Interestingly, as compared to controls, overweight and obese mice consumed smaller amounts of palatable foods (isocaloric milk or sucrose, in either the presence or absence of their respective maintenance diets: standard, low fat-high carbohydrate or high fat-high carbohydrate. Notably, however, all groups adjusted their consumption of the different food types, such that their body weight-corrected daily intake of calories remained constant. Thus, overeating in mice does not reflect a reward deficiency syndrome and, in contrast to humans, mice regulate their caloric intake according to metabolic status rather than to the hedonic properties of a particular food. Together, these observations demonstrate that excess weight masks the capacity for appetitive learning in

  3. 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].

  4. Visualizing olfactory learning functional imaging of experience-induced olfactory bulb changes.

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    Fletcher, Max L; Bendahmane, Mounir

    2014-01-01

    The anatomical organization of sensory neuron input allows odor information to be transformed into odorant-specific spatial maps of mitral/tufted cell glomerular activity. In other sensory systems, neuronal representations of sensory stimuli can be reorganized or enhanced following learning or experience. Similarly, several studies have demonstrated both structural and physiological experience-induced changes throughout the olfactory system. As experience-induced changes within this circuit likely serve as an initial site for odor memory formation, the olfactory bulb is an ideal site for optical imaging studies of olfactory learning, as they allow for the visualization of experience-induced changes in the glomerular circuit following learning and how these changes impact of odor representations with the bulb. Presently, optical imaging techniques have been used to visualize experience-induced changes in glomerular odor representations in a variety of paradigms in short-term habituation, chronic odor exposure, and olfactory associative conditioning. © 2014 Elsevier B.V. All rights reserved.

  5. Histone acetylation in the olfactory bulb of young rats facilitates aversive olfactory learning and synaptic plasticity.

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    Wang, Y-J; Okutani, F; Murata, Y; Taniguchi, M; Namba, T; Kaba, H

    2013-03-01

    Epigenetic mechanisms play an important role in memory formation and synaptic plasticity. Specifically, histone-associated heterochromatin undergoes changes in structure during the early stages of long-term memory formation. In keeping with the classical conditioning paradigm, young rats have been shown to exhibit aversion to an odor stimulus initially presented during foot shock. We previously showed that synaptic plasticity at the dendrodendritic synapses between mitral and granule cells in the olfactory bulb (OB) underlies this aversive olfactory learning. However, the epigenetic mechanisms involved are not well characterized. Therefore, we examined whether intrabulbar infusion of trichostatin A (TSA), a histone deacetylase inhibitor, facilitates olfactory learning in young rats. TSA infusion during odor-shock training enhanced a conditioned odor aversion in a dose-dependent manner and prolonged the learned aversion. Western blot and immunohistochemical analyses showed that the level of histone H4 acetylation significantly increased until 4 h after odor-shock training in both mitral and granule cells in the OB, whereas histone H3 acetylation returned to the control level at 2 h after the training. We also obtained evidence that TSA infusion elevated acetylation of histone H4 or H3. Furthermore, in vitro electrophysiological analysis using slices of the OB revealed that application of TSA significantly enhanced the long-term potentiation induced in synaptic transmission from mitral to granule cells at dendrodendritic synapses. Taken together, these results provide evidence that histone H4 and H3 acetylation in the OB is an epigenetic mechanism associated with aversive olfactory learning in young rats.

  6. Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

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    Bryon Silva

    2015-01-01

    Full Text Available The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS, with an unconditioned stimulus (US. The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB, can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh receptors, while the US is encoded by biogenic amine (BA systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila.

  7. Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

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    Silva, Bryon; Molina-Fernández, Claudia; Ugalde, María Beatriz; Tognarelli, Eduardo I.; Angel, Cristian; Campusano, Jorge M.

    2015-01-01

    The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS), with an unconditioned stimulus (US). The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB), can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh) receptors, while the US is encoded by biogenic amine (BA) systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs) contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila. PMID:26380118

  8. 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.

  9. Machine-learned pattern identification in olfactory subtest results

    Science.gov (United States)

    Lötsch, Jörn; Hummel, Thomas; Ultsch, Alfred

    2016-01-01

    The human sense of smell is often analyzed as being composed of three main components comprising olfactory threshold, odor discrimination and the ability to identify odors. A relevant distinction of the three components and their differential changes in distinct disorders remains a research focus. The present data-driven analysis aimed at establishing a cluster structure in the pattern of olfactory subtest results. Therefore, unsupervised machine-learning was applied onto olfactory subtest results acquired in 10,714 subjects with nine different olfactory pathologies. Using the U-matrix, Emergent Self-organizing feature maps (ESOM) identified three different clusters characterized by (i) low threshold and good discrimination and identification, (ii) very high threshold associated with absent to poor discrimination and identification ability, or (iii) medium threshold, i.e., in the mid-range of possible thresholds, associated with reduced discrimination and identification ability. Specific etiologies of olfactory (dys)function were unequally represented in the clusters (p pattern recognition. PMID:27762302

  10. Contrasting role of octopamine in appetitive and aversive learning in the crab Chasmagnathus.

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    Laura Kaczer

    Full Text Available BACKGROUND: Biogenic amines are implicated in reinforcing associative learning. Octopamine (OA is considered the invertebrate counterpart of noradrenaline and several studies in insects converge on the idea that OA mediates the reward in appetitive conditioning. However, it is possible to assume that OA could have a different role in an aversive conditioning. METHODOLOGY/PRINCIPAL FINDINGS: Here we pharmacologically studied the participation of OA in two learning processes in the crab Chasmagnathus granulatus, one appetitive and one aversive. It is shown that the aversive memory is impaired by an OA injection applied immediately or 30 minutes after the last training trial. By contrast, the appetitive memory is blocked by OA antagonists epinastine and mianserine, but enhanced by OA when injected together with the supply of a minimum amount of reinforcement. Finally, double-learning experiments in which crabs are given the aversive and the appetitive learning either successively or simultaneously allow us to study the interaction between both types of learning and analyze the presumed action of OA. We found that the appetitive training offered immediately, but not one hour, after an aversive training has an amnesic effect on the aversive memory, mimicking the effect and the kinetic of an OA injection. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that the role of OA is divergent in two memory processes of opposite signs: on the one hand it would mediate the reinforcement in appetitive learning, and on the other hand it has a deleterious effect over aversive memory consolidation.

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

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    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. Roles of octopamine and dopamine in appetitive and aversive memory acquisition studied in olfactory conditioning of maxillary palpi extension response in crickets.

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    Yukihisa eMatsumoto

    2015-09-01

    Full Text Available Elucidation of reinforcing mechanisms for associative learning is an important subject in neuroscience. Based on results of our previous pharmacological studies in crickets, we suggested that octopamine and dopamine mediate reward and punishment signals, respectively, in associative learning. In fruit-flies, however, it was concluded that dopamine mediates both appetitive and aversive reinforcement, which differs from our suggestion in crickets. In our previous studies, the effect of conditioning was tested at 30 min after training or later, due to limitations of our experimental procedures, and thus the possibility that octopamine and dopamine were not needed for initial acquisition of learning was not ruled out. In this study we first established a conditioning procedure to enable us to evaluate acquisition performance in crickets. Crickets extended their maxillary palpi and vigorously swung them when they perceived some odors, and we found that crickets that received pairing of an odor with water reward or sodium chloride punishment exhibited an increase or decrease in percentages of maxillary palpi extension responses to the odor. Using this procedure, we found that octopamine and dopamine receptor antagonists impair acquisition of appetitive and aversive learning, respectively. This finding suggests that neurotransmitters mediating appetitive reinforcement differ in crickets and fruit-flies.

  13. Gustatory response and appetitive learning in Microplitis croceipes in relation to sugar type and concentration

    NARCIS (Netherlands)

    Wäckers, F.L.; Bonifay, C.; Vet, L.E.M.; Lewis, W.J.

    2006-01-01

    Insects can be conditioned to respond to odours through associative learning. Various learning parameters, such as the rate of odour acquisition, are known to depend on the type of conditioned stimulus. Here we investigate to what extent appetitive conditioning in the parasitoid Microplitis croceipe

  14. Appetitive and aversive visual learning in freely moving Drosophila

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    Christopher Schnaitmann

    2010-03-01

    Full Text Available To compare appetitive and aversive visual memories of the fruit fly Drosophila melanogaster, we developed a new paradigm for classical conditioning. Adult flies are trained en masse to differentially associate one of two visual conditioned stimuli (blue and green light as conditioned stimuli or CS with an appetitive or aversive chemical substance (unconditioned stimulus or US. In a test phase, flies are given a choice between the paired and the unpaired visual stimuli. Associative memory is measured based on altered visual preference in the test. If a group of flies has, for example, received a sugar reward with green light, they show a significantly higher preference for the green stimulus during the test than another group of flies having received the same reward with blue light. We demonstrate critical parameters for the formation of visual appetitive memory, such as training repetition, order of reinforcement, starvation, and individual conditioning. Furthermore, we show that formic acid can act as an aversive chemical reinforcer, yielding weak, yet significant, aversive memory. These results provide a basis for future investigations into the cellular and molecular mechanisms underlying visual memory and perception in Drosophila.

  15. The combination of appetitive and aversive reinforcers and the nature of their interaction during auditory learning.

    Science.gov (United States)

    Ilango, A; Wetzel, W; Scheich, H; Ohl, F W

    2010-03-31

    Learned changes in behavior can be elicited by either appetitive or aversive reinforcers. It is, however, not clear whether the two types of motivation, (approaching appetitive stimuli and avoiding aversive stimuli) drive learning in the same or different ways, nor is their interaction understood in situations where the two types are combined in a single experiment. To investigate this question we have developed a novel learning paradigm for Mongolian gerbils, which not only allows rewards and punishments to be presented in isolation or in combination with each other, but also can use these opposite reinforcers to drive the same learned behavior. Specifically, we studied learning of tone-conditioned hurdle crossing in a shuttle box driven by either an appetitive reinforcer (brain stimulation reward) or an aversive reinforcer (electrical footshock), or by a combination of both. Combination of the two reinforcers potentiated speed of acquisition, led to maximum possible performance, and delayed extinction as compared to either reinforcer alone. Additional experiments, using partial reinforcement protocols and experiments in which one of the reinforcers was omitted after the animals had been previously trained with the combination of both reinforcers, indicated that appetitive and aversive reinforcers operated together but acted in different ways: in this particular experimental context, punishment appeared to be more effective for initial acquisition and reward more effective to maintain a high level of conditioned responses (CRs). The results imply that learning mechanisms in problem solving were maximally effective when the initial punishment of mistakes was combined with the subsequent rewarding of correct performance.

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

    Science.gov (United States)

    Fletcher, Max L.; Chen, Wei R.

    2010-01-01

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

  17. Activation of nucleus accumbens NMDA receptors differentially affects appetitive or aversive taste learning and memory

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    Luis eNuñez-Jaramillo

    2012-04-01

    Full Text Available Taste memory depends on motivational and post-ingestional consequences; thus, it can be aversive (e.g., conditioned taste aversion, CTA if a novel, palatable taste is paired with visceral malaise, or it can be appetitive if no intoxication appears after novel taste consumption, and a taste preference is developed. The nucleus accumbens (NAc plays a role in hedonic reactivity to taste stimuli, and recent findings suggest that reward and aversion are differentially encoded by the activity of NAc neurons. The present study examined whether the requirement for NMDA receptors in the NAc core during rewarding appetitive taste learning differs from that during aversive taste conditioning, as well as during retrieval of appetitive versus aversive taste memory, using the taste preference or CTA model, respectively. Bilateral infusions of NMDA (1 μg/μl, 0.5 μl into the NAc core were performed before acquisition or before retrieval of taste preference or CTA. Activation of NMDA receptors before taste preference training or CTA acquisition did not alter memory formation. Furthermore, NMDA injections before aversive taste retrieval had no effect on taste memory; however, 24 h later, CTA extinction was significantly delayed. Also, NMDA injections, made before familiar appetitive memory retrieval, interrupted the development of taste preference and produced a preference delay 24 h later. These results suggest that memory formation for a novel taste produces neurochemical changes in the NAc core that have differential requirements for NMDA receptors during retrieval of appetitive or aversive memory.

  18. Learning and the persistence of appetite: extinction and the motivation to eat and overeat.

    Science.gov (United States)

    Bouton, Mark E

    2011-04-18

    The modern world is saturated with highly palatable and highly available food, providing many opportunities to associate food with environmental cues and actions (through Pavlovian and operant or instrumental learning, respectively). Basic learning processes can often increase the tendency to approach and consume food, whereas extinction, in which Pavlovian and operant behaviors decline when the reinforcer is withheld, weakens but does not erase those tendencies. Contemporary research suggests that extinction involves an inhibitory form of new learning that appears fragile because it is highly dependent on the context for expression. These ideas are supported by the phenomena of renewal, spontaneous recovery, resurgence, reinstatement, and rapid reacquisition in appetitive learning, which together may help explain why overeating may be difficult to suppress permanently, and why appetitive behavior may seem so persistent.

  19. 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.

  20. Focal Uncaging of GABA Reveals a Temporally Defined Role for GABAergic Inhibition during Appetitive Associative Olfactory Conditioning in Honeybees

    Science.gov (United States)

    Raccuglia, Davide; Mueller, Uli

    2013-01-01

    Throughout the animal kingdom, the inhibitory neurotransmitter ?-aminobutyric acid (GABA) is a key modulator of physiological processes including learning. With respect to associative learning, the exact time in which GABA interferes with the molecular events of learning has not yet been clearly defined. To address this issue, we used two…

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

    Science.gov (United States)

    Ishida, Yuko; Ozaki, Mamiko

    2012-01-01

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

  2. Action Learning in an SME: Appetite Comes with Eating

    Science.gov (United States)

    Hauser, Bernhard

    2009-01-01

    This account describes action learning in a small to medium-size enterprise (SME) that operates as a local power utility on an established market that is currently going through a process of radical transformation. The task of the action learning set was to improve the flow of information to employees about the evolving framework in which the…

  3. Ventral tegmental area neurons in learned appetitive behavior and positive reinforcement.

    Science.gov (United States)

    Fields, Howard L; Hjelmstad, Gregory O; Margolis, Elyssa B; Nicola, Saleem M

    2007-01-01

    Ventral tegmental area (VTA) neuron firing precedes behaviors elicited by reward-predictive sensory cues and scales with the magnitude and unpredictability of received rewards. These patterns are consistent with roles in the performance of learned appetitive behaviors and in positive reinforcement, respectively. The VTA includes subpopulations of neurons with different afferent connections, neurotransmitter content, and projection targets. Because the VTA and substantia nigra pars compacta are the sole sources of striatal and limbic forebrain dopamine, measurements of dopamine release and manipulations of dopamine function have provided critical evidence supporting a VTA contribution to these functions. However, the VTA also sends GABAergic and glutamatergic projections to the nucleus accumbens and prefrontal cortex. Furthermore, VTA-mediated but dopamine-independent positive reinforcement has been demonstrated. Consequently, identifying the neurotransmitter content and projection target of VTA neurons recorded in vivo will be critical for determining their contribution to learned appetitive behaviors.

  4. Behavioural and neurophysiological study of olfactory perception and learning in honeybees

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    Jean-Christophe eSandoz

    2011-12-01

    Full Text Available The honeybee Apis mellifera has been a central insect model in the study of olfactory perception and learning for more than a century, starting with pioneer work by Karl von Frisch. Research on olfaction in honeybees has greatly benefited from the advent of a range of behavioural and neurophysiological paradigms in the Lab. Here I review major findings about how the honeybee brain detects, processes, and learns odours, based on behavioural, neuroanatomical and neurophysiological approaches. I first address the behavioural study of olfactory learning, from experiments on free-flying workers visiting artificial flowers to laboratory-based conditioning protocols on restrained individuals. I explain how the study of olfactory learning has allowed understanding the discrimination and generalization ability of the honeybee olfactory system, its capacity to grant special properties to olfactory mixtures as well as to retain individual component information. Next, based on the impressive amount of anatomical and immunochemical studies of the bee brain, I detail our knowledge of olfactory pathways. I then show how functional recordings of odour-evoked activity in the brain allow following the transformation of the olfactory message from the periphery until higher-order central structures. Data from extra- and intracellular electrophysiological approaches as well as from the most recent optical imaging developments are described. Lastly, I discuss results addressing how odour representation changes as a result of experience. This impressive ensemble of behavioural, neuroanatomical and neurophysiological data available in the bee make it an attractive model for future research aiming to understand olfactory perception and learning in an integrative fashion.

  5. Aversive learning in honeybees revealed by the olfactory conditioning of the sting extension reflex.

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    Vanina Vergoz

    Full Text Available Invertebrates have contributed greatly to our understanding of associative learning because they allow learning protocols to be combined with experimental access to the nervous system. The honeybee Apis mellifera constitutes a standard model for the study of appetitive learning and memory since it was shown, almost a century ago, that bees learn to associate different sensory cues with a reward of sugar solution. However, up to now, no study has explored aversive learning in bees in such a way that simultaneous access to its neural bases is granted. Using odorants paired with electric shocks, we conditioned the sting extension reflex, which is exhibited by harnessed bees when subjected to a noxious stimulation. We show that this response can be conditioned so that bees learn to extend their sting in response to the odorant previously punished. Bees also learn to extend the proboscis to one odorant paired with sugar solution and the sting to a different odorant paired with electric shock, thus showing that they can master both appetitive and aversive associations simultaneously. Responding to the appropriate odorant with the appropriate response is possible because two different biogenic amines, octopamine and dopamine subserve appetitive and aversive reinforcement, respectively. While octopamine has been previously shown to substitute for appetitive reinforcement, we demonstrate that blocking of dopaminergic, but not octopaminergic, receptors suppresses aversive learning. Therefore, aversive learning in honeybees can now be accessed both at the behavioral and neural levels, thus opening new research avenues for understanding basic mechanisms of learning and memory.

  6. Internal cholinergic regulation of learning and recall in a model of olfactory processing

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    Licurgo Benemann Almeida

    2016-11-01

    Full Text Available In the olfactory system, cholinergic modulation has been associated with contrast modulation and changes in receptive fields in the olfactory bulb, as well the learning of odor associations in olfactory cortex. Computational modeling and behavioral studies suggest that cholinergic modulation could improve sensory processing and learning while preventing pro-active interference when task demands are high. However, how sensory inputs and/or learning regulate incoming modulation has not yet been elucidated. We here use a computational model of the olfactory bulb, piriform cortex (PC and horizontal limb of the diagonal band of Broca (HDB to explore how olfactory learning could regulate cholinergic inputs to the system in a closed feedback loop. In our model, the novelty of an odor is reflected in firing rates and sparseness of cortical neurons in response to that odor and these firing rates can directly regulate learning in the system by modifying cholinergic inputs to the system. In the model, cholinergic neurons reduce their firing in response to familiar odors – reducing plasticity in the PC, but increase their firing in response to novel odor – increasing PC plasticity. Recordings from HDB neurons in awake behaving rats reflect predictions from the model by showing that a subset of neurons decrease their firing as an odor becomes familiar.

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

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    Mareike Selcho

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

  8. Upregulation of Neurotrophic Factors Selectively in Frontal Cortex in Response to Olfactory Discrimination Learning

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    Ari Naimark

    2007-01-01

    Full Text Available We have previously shown that olfactory discrimination learning is accompanied by several forms of long-term enhancement in synaptic connections between layer II pyramidal neurons selectively in the piriform cortex. This study sought to examine whether the previously demonstrated olfactory-learning-task-induced modifications are preceded by suitable changes in the expression of mRNA for neurotrophic factors and in which brain areas this occurs. Rats were trained to discriminate positive cues in pair of odors for a water reward. The relationship between the learning task and local levels of mRNA for brain-derived neurotrophic factor, tyrosine kinase B, nerve growth factor, and neurotrophin-3 in the frontal cortex, hippocampal subregions, and other regions were assessed 24 hours post olfactory learning. The olfactory discrimination learning activated production of endogenous neurotrophic factors and induced their signal transduction in the frontal cortex, but not in other brain areas. These findings suggest that different brain areas may be preferentially involved in different learning/memory tasks.

  9. Pontomesencephalic Tegmental Afferents to VTA Non-dopamine Neurons Are Necessary for Appetitive Pavlovian Learning

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    Hau-Jie Yau

    2016-09-01

    Full Text Available The ventral tegmental area (VTA receives phenotypically distinct innervations from the pedunculopontine tegmental nucleus (PPTg. While PPTg-to-VTA inputs are thought to play a critical role in stimulus-reward learning, direct evidence linking PPTg-to-VTA phenotypically distinct inputs in the learning process remains lacking. Here, we used optogenetic approaches to investigate the functional contribution of PPTg excitatory and inhibitory inputs to the VTA in appetitive Pavlovian conditioning. We show that photoinhibition of PPTg-to-VTA cholinergic or glutamatergic inputs during cue presentation dampens the development of anticipatory approach responding to the food receptacle during the cue. Furthermore, we employed in vivo optetrode recordings to show that photoinhibition of PPTg cholinergic or glutamatergic inputs significantly decreases VTA non-dopamine (non-DA neural activity. Consistently, photoinhibition of VTA non-DA neurons disrupts the development of cue-elicited anticipatory approach responding. Taken together, our study reveals a crucial regulatory mechanism by PPTg excitatory inputs onto VTA non-DA neurons during appetitive Pavlovian conditioning.

  10. Pontomesencephalic Tegmental Afferents to VTA Non-dopamine Neurons Are Necessary for Appetitive Pavlovian Learning.

    Science.gov (United States)

    Yau, Hau-Jie; Wang, Dong V; Tsou, Jen-Hui; Chuang, Yi-Fang; Chen, Billy T; Deisseroth, Karl; Ikemoto, Satoshi; Bonci, Antonello

    2016-09-01

    The ventral tegmental area (VTA) receives phenotypically distinct innervations from the pedunculopontine tegmental nucleus (PPTg). While PPTg-to-VTA inputs are thought to play a critical role in stimulus-reward learning, direct evidence linking PPTg-to-VTA phenotypically distinct inputs in the learning process remains lacking. Here, we used optogenetic approaches to investigate the functional contribution of PPTg excitatory and inhibitory inputs to the VTA in appetitive Pavlovian conditioning. We show that photoinhibition of PPTg-to-VTA cholinergic or glutamatergic inputs during cue presentation dampens the development of anticipatory approach responding to the food receptacle during the cue. Furthermore, we employed in vivo optetrode recordings to show that photoinhibition of PPTg cholinergic or glutamatergic inputs significantly decreases VTA non-dopamine (non-DA) neural activity. Consistently, photoinhibition of VTA non-DA neurons disrupts the development of cue-elicited anticipatory approach responding. Taken together, our study reveals a crucial regulatory mechanism by PPTg excitatory inputs onto VTA non-DA neurons during appetitive Pavlovian conditioning.

  11. Invertebrate learning and memory: Fifty years of olfactory conditioning of the proboscis extension response in honeybees.

    Science.gov (United States)

    Giurfa, Martin; Sandoz, Jean-Christophe

    2012-02-01

    The honeybee Apis mellifera has emerged as a robust and influential model for the study of classical conditioning, thanks to the existence of a powerful Pavlovian conditioning protocol, the olfactory conditioning of the proboscis extension response (PER). In 2011, the olfactory PER conditioning protocol celebrates 50 years since it was first introduced by Kimihisa Takeda in 1961. Here, we review its origins, developments, and perspectives in order to define future research avenues and necessary methodological and conceptual evolutions. We show that olfactory PER conditioning has become a versatile tool for the study of questions in extremely diverse fields in addition to the study of learning and memory and that it has allowed behavioral characterizations, not only of honeybees, but also of other insect species, for which the protocol was adapted. We celebrate, therefore, Takeda's original work and prompt colleagues to conceive and establish further robust behavioral tools for an accurate characterization of insect learning and memory at multiple levels of analysis.

  12. Large-scale assessment of olfactory preferences and learning in Drosophila melanogaster: behavioral and genetic components

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    Elisabetta Versace

    2015-09-01

    Full Text Available In the Evolve and Resequence method (E&R, experimental evolution and genomics are combined to investigate evolutionary dynamics and the genotype-phenotype link. As other genomic approaches, this methods requires many replicates with large population sizes, which imposes severe restrictions on the analysis of behavioral phenotypes. Aiming to use E&R for investigating the evolution of behavior in Drosophila, we have developed a simple and effective method to assess spontaneous olfactory preferences and learning in large samples of fruit flies using a T-maze. We tested this procedure on (a a large wild-caught population and (b 11 isofemale lines of Drosophila melanogaster. Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples. Consistent with previous results, we show that flies have a preference for orange vs. apple odor. With our procedure wild-derived flies exhibit olfactory learning in the absence of previous laboratory selection. Furthermore, we find genetic differences in the olfactory learning with relatively high heritability. We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

  13. Coordinated activity of ventral tegmental neurons adapts to appetitive and aversive learning.

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    Yunbok Kim

    Full Text Available Our understanding of how value-related information is encoded in the ventral tegmental area (VTA is based mainly on the responses of individual putative dopamine neurons. In contrast to cortical areas, the nature of coordinated interactions between groups of VTA neurons during motivated behavior is largely unknown. These interactions can strongly affect information processing, highlighting the importance of investigating network level activity. We recorded the activity of multiple single units and local field potentials (LFP in the VTA during a task in which rats learned to associate novel stimuli with different outcomes. We found that coordinated activity of VTA units with either putative dopamine or GABA waveforms was influenced differently by rewarding versus aversive outcomes. Specifically, after learning, stimuli paired with a rewarding outcome increased the correlation in activity levels between unit pairs whereas stimuli paired with an aversive outcome decreased the correlation. Paired single unit responses also became more redundant after learning. These response patterns flexibly tracked the reversal of contingencies, suggesting that learning is associated with changing correlations and enhanced functional connectivity between VTA neurons. Analysis of LFP recorded simultaneously with unit activity showed an increase in the power of theta oscillations when stimuli predicted reward but not an aversive outcome. With learning, a higher proportion of putative GABA units were phase locked to the theta oscillations than putative dopamine units. These patterns also adapted when task contingencies were changed. Taken together, these data demonstrate that VTA neurons organize flexibly as functional networks to support appetitive and aversive learning.

  14. Inhibiting DNA methylation alters olfactory extinction but not acquisition learning in Apis cerana and Apis mellifera.

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    Gong, Zhiwen; Wang, Chao; Nieh, James C; Tan, Ken

    2016-07-01

    DNA methylation plays a key role in invertebrate acquisition and extinction memory. Honey bees have excellent olfactory learning, but the role of DNA methylation in memory formation has, to date, only been studied in Apis mellifera. We inhibited DNA methylation by inhibiting DNA methyltransferase (DNMT) with zebularine (zeb) and studied the resulting effects upon olfactory acquisition and extinction memory in two honey bee species, Apis cerana and A. mellifera. We used the proboscis extension reflex (PER) assay to measure memory. We provide the first demonstration that DNA methylation is also important in the olfactory extinction learning of A. cerana. DNMT did not reduce acquisition learning in either species. However, zeb bidirectionally and differentially altered extinction learning in both species. In particular, zeb provided 1h before acquisition learning improved extinction memory retention in A. mellifera, but reduced extinction memory retention in A. cerana. The reasons for these differences are unclear, but provide a basis for future studies to explore species-specific differences in the effects of methylation on memory formation.

  15. Two pairs of tentacles and a pair of procerebra: optimized functions and redundant structures in the sensory and central organs involved in olfactory learning of terrestrial pulmonates.

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    Matsuo, Ryota; Kobayashi, Suguru; Yamagishi, Miki; Ito, Etsuro

    2011-03-15

    Terrestrial pulmonates can learn olfactory-aversion tasks and retain them in their long-term memory. To elucidate the cellular mechanisms underlying learning and memory, researchers have focused on both the peripheral and central components of olfaction: two pairs of tentacles (the superior and inferior tentacles) and a pair of procerebra, respectively. Data from tentacle-amputation experiments showed that either pair of tentacles is sufficient for olfactory learning. Results of procerebrum lesion experiments showed that the procerebra are necessary for olfactory learning but that either one of the two procerebra, rather than both, is used for each olfactory learning event. Together, these data suggest that there is a redundancy in the structures of terrestrial pulmonates necessary for olfactory learning. In our commentary we exemplify and discuss functional optimization and structural redundancy in the sensory and central organs involved in olfactory learning and memory in terrestrial pulmonates.

  16. Two Pairs of Mushroom Body Efferent Neurons Are Required for Appetitive Long-Term Memory Retrieval in Drosophila

    Directory of Open Access Journals (Sweden)

    Pierre-Yves Plaçais

    2013-11-01

    Full Text Available One of the challenges facing memory research is to combine network- and cellular-level descriptions of memory encoding. In this context, Drosophila offers the opportunity to decipher, down to single-cell resolution, memory-relevant circuits in connection with the mushroom bodies (MBs, prominent structures for olfactory learning and memory. Although the MB-afferent circuits involved in appetitive learning were recently described, the circuits underlying appetitive memory retrieval remain unknown. We identified two pairs of cholinergic neurons efferent from the MB α vertical lobes, named MB-V3, that are necessary for the retrieval of appetitive long-term memory (LTM. Furthermore, LTM retrieval was correlated to an enhanced response to the rewarded odor in these neurons. Strikingly, though, silencing the MB-V3 neurons did not affect short-term memory (STM retrieval. This finding supports a scheme of parallel appetitive STM and LTM processing.

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

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

    2010-01-01

    Summary Olfactory signals influence social interactions in a variety of species [1, 2]. In mammals, pheromones and other social cues can promote mating or aggression behaviors, can communicate information about social hierarchies, genetic identity and health status, and can contribute to associative learning [1–5]. However, the molecular, cellular and neural mechanisms underlying many olfactory-mediated social interactions remain poorly understood. Here, we report that a specialized olfactory subsystem that includes olfactory sensory neurons (OSNs) expressing the receptor guanylyl cyclase GC-D, the cyclic nucleotide-gated channel subunit CNGA3 and the carbonic anhydrase isoform CAII (GC-D+ OSNs) [6–11] is required for the acquisition of socially transmitted food preferences (STFPs) in mice. Using electrophysiological recordings from gene-targeted mice, we show that GC-D+ OSNs are highly sensitive to the volatile semiochemical carbon disulfide (CS2), a component of rodent breath and a known social signal mediating the acquisition of STFPs [12–14]. Responses to sub-micromolar concentrations of CS2 in the main olfactory epithelium or in identified GC-D+ OSNs are absent in mice lacking CNGA3 or CAII and drastically reduced in mice lacking GC-D. Mice in which GC-D+ OSN transduction mechanisms have been disrupted fail to acquire STFPs from either live or surrogate demonstrator mice and do not exhibit neuronal activation of the ventral subiculum of the hippocampus, a brain region implicated in STFP retrieval [15]. Our findings indicate that GC-D+ OSNs detect chemosignals that facilitate food-related social interactions. PMID:20637621

  18. Spatial Olfactory Learning Contributes to Place Field Formation in the Hippocampus

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    Zhang, Sijie; Manahan-Vaughan, Denise

    2015-01-01

    Spatial encoding in the hippocampus is multifactorial, and it is well established that metric information about space is conferred by place cells that fire when an animal finds itself in a specific environmental location. Visuospatial contexts comprise a key element in the formation of place fields. Nevertheless, hippocampus does not only use visual cues to generate spatial representations. In the absence of visual input, both humans and other vertebrates studied in this context, are capable of generating very effective spatial representations. However, little is known about the relationship between nonvisual sensory modalities and the establishment of place fields. Substantial evidence exists that olfactory information can be used to learn spatial contexts. Here, we report that learning about a distinct odor constellation in an environment, where visual and auditory cues are suppressed, results in stable place fields that rotate when the odor constellations are rotated and remap when the odor constellations are shuffled. These data support that the hippocampus can use nonvisuospatial resources, and specifically can use spatial olfactory information, to generate spatial representations. Despite the less precise nature of olfactory stimuli compared with visual stimuli, these can substitute for visual inputs to enable the acquisition of metric information about space. PMID:24008582

  19. Olfactory learning and memory in the bumblebee Bombus occidentalis

    Science.gov (United States)

    Riveros, Andre J.; Gronenberg, Wulfila

    2009-07-01

    In many respects, the behavior of bumblebees is similar to that of the closely related honeybees, a long-standing model system for learning and memory research. Living in smaller and less regulated colonies, bumblebees are physiologically more robust and thus have advantages in particular for indoor experiments. Here, we report results on Pavlovian odor conditioning of bumblebees using the proboscis extension reflex (PER) that has been successfully used in honeybee learning research. We examine the effect of age, body size, and experience on learning and memory performance. We find that age does not affect learning and memory ability, while body size positively correlates with memory performance. Foraging experience seems not to be necessary for learning to occur, but it may contribute to learning performance as bumblebees with more foraging experience on average were better learners. The PER represents a reliable tool for learning and memory research in bumblebees and allows examining interspecific similarities and differences of honeybee and bumblebee behavior, which we discuss in the context of social organization.

  20. CD146 deletion in the nervous system impairs appetite, locomotor activity and spatial learning in mice.

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    Tu, Tao; Gao, Qian; Luo, Yongting; Chen, Jianan; Lu, Di; Feng, Jing; Yang, Dongling; Song, Lina; Yan, Xiyun

    2013-01-01

    Cell adhesion molecules (CAMs) are crucial effectors for the development and maintenance of the nervous system. Mutations in human CAM genes are linked to brain disorders and psychological diseases, and CAM knockout mice always exhibit similar behavioral abnormalities. CD146 is a CAM of the immunoglobulin superfamily that interacts with Neurite Outgrowth Factor and involved in neurite extension in vitro. However, little is known about its in vivo function in the nervous system. In this study, we used a murine CD146 nervous system knockout (CD146(ns-ko)) model. We found that the brains of some CD146(ns-ko) mice were malformed with small olfactory bulbs. CD146(ns-ko) mice exhibited lower body weights and smaller food intake when compared with wild type littermates. Importantly, behavior tests revealed that CD146(ns-ko) mice exhibited significant decreased locomotor activity and impaired capacity for spatial learning and memory. Our results demonstrate that CD146 is important for mammalian nervous system development and proper behavior patterns.

  1. Context-dependent olfactory learning monitored by activities of salivary neurons in cockroaches.

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    Matsumoto, Chihiro Sato; Matsumoto, Yukihisa; Watanabe, Hidehiro; Nishino, Hiroshi; Mizunami, Makoto

    2012-01-01

    Context-dependent discrimination learning, a sophisticated form of nonelemental associative learning, has been found in many animals, including insects. The major purpose of this research is to establish a method for monitoring this form of nonelemental learning in rigidly restrained insects for investigation of underlying neural mechanisms. We report context-dependent olfactory learning (occasion-setting problem solving) of salivation, which can be monitored as activity changes of salivary neurons in immobilized cockroaches, Periplaneta americana. A group of cockroaches was trained to associate peppermint odor (conditioned stimulus, CS) with sucrose solution reward (unconditioned stimulus, US) while vanilla odor was presented alone without pairing with the US under a flickering light condition (1.0 Hz) and also trained to associate vanilla odor with sucrose reward while peppermint odor was presented alone under a steady light condition. After training, the responses of salivary neurons to the rewarded peppermint odor were significantly greater than those to the unrewarded vanilla odor under steady illumination and those to the rewarded vanilla odor was significantly greater than those to the unrewarded peppermint odor in the presence of flickering light. Similar context-dependent responses were observed in another group of cockroaches trained with the opposite stimulus arrangement. This study demonstrates context-dependent olfactory learning of salivation for the first time in any vertebrate and invertebrate species, which can be monitored by activity changes of salivary neurons in restrained cockroaches. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Learning the way to blood: first evidence of dual olfactory conditioning in a blood-sucking insect, Rhodnius prolixus. II. Aversive learning.

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    Vinauger, Clément; Buratti, Laura; Lazzari, Claudio R

    2011-09-15

    After having demonstrated that blood-sucking bugs are able to associate a behaviourally neutral odour (L-lactic acid) with positive reinforcement (i.e. appetitive conditioning) in the first part of this study, we tested whether these insects were also able to associate the same odour with a negative reinforcement (i.e. aversive conditioning). Learned aversion to host odours has been repeatedly suggested as a determinant for the distribution of disease vectors among host populations. Nevertheless, no experimental evidence has been obtained so far. Adapting a classical conditioning approach to our haematophagous model, we trained larvae of Rhodnius prolixus to associate L-lactic acid, an odour perceived by bugs but behaviourally neutral when presented alone, with a mechanical perturbation (i.e. negative reinforcement). Naive bugs and bugs exposed to CS, punishment, or CS and punishment without contingency remained indifferent to the presence of an air stream loaded with L-lactic acid (random orientation on a locomotion compensator), whereas the groups previously exposed to the contingency CS-punishment were significantly repelled by L-lactic acid. In a companion paper, the opposite, i.e. attraction, was induced in bugs exposed to the contingency of the same odour with a positive reinforcement. These constitute the first pieces of evidence of olfactory conditioning in triatomine bugs and the first demonstration that the same host odour can be used by insects that are disease vectors to learn to recognize either a host to feed on or a potentially defensive one. The orientation mechanism during repulsion is also discussed in light of our results.

  3. Involvement of the histaminergic system on appetitive learning and its interaction with haloperidol in goldfish.

    Science.gov (United States)

    Medalha, Carla Christina; Mattioli, Rosana

    2007-05-17

    This study investigated the actions of the histaminergic system on appetitive learning and memory, and its interaction with the dopaminergic system in goldfish. It consisted of nine sessions, in which fish were tested in a four-arm tank. On day 1, the animals were habituated for 10 min. On day 2, they were placed in one arm and had to find food at the left or the right arm. Time to begin feeding was recorded, and the procedure repeated for more 3 days (training phase). On training day 4, seven groups were injected with saline, seven with haloperidol (2.0 mg/kg) and one with DMSO solution before training and after feeding, three groups received saline, six chlorpheniramine (CPA) (1.0, 4.0 and 8.0 mg/kg), and six l-histidine (LH) (25, 50 and 100 mg/kg). Saline groups were considered as control of CPA and LH treated groups and DMSO as control of haloperidol. A non-injected group was also included. Testing occurred after 24 h. A reversal procedure was conducted 24h after testing and repeated for 3 days. The groups receiving CPA at 1.0 and 8.0 mg/kg and LH at 25, 50 and 100 mg/kg differed between Test and Reversal day 1. Pre-treatment with haloperidol plus 8.0 mg/kg of CPA and 25 and 50 mg/kg of LH reverted the treatment effect. However, in the groups treated with 1.0 mg/kg of CPA and 100 mg/kg of LH, the difference remained. This study confirmed the interaction between the histaminergic and the dopaminergic systems on memory process in goldfish.

  4. Matching- and nonmatching-to-sample concept learning in rats using olfactory stimuli.

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

    2011-09-01

    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 matching or nonmatching training with 10 exemplars, the contingencies were reversed with five new stimuli such that subjects trained on matching were shifted to nonmatching and vice versa. Following these reversed contingencies, the effects of the original training persisted for many trials with new exemplars. In Experiment 2, 9 rats were trained with matching procedures in an arena that provided for 18 different spatial locations for comparison stimuli. Five subjects were trained with differential reinforcement outcomes and 4 with only one type of reinforcer. Differential outcomes and multiple exemplars facilitated learning, and there was strong evidence for generalization to new stimuli for most rats that acquired several conditional discriminations. Performances with novel samples were generally above chance, but rarely reached the high levels obtained during baseline with well-trained stimulus relations. However, taken together, the data from the two experiments extend previous work, show that rats can learn both match and nonmatch relations with different experimental protocols, and demonstrate generalization to novel sample stimuli.

  5. Olfactory-learning abilities are correlated with the rate by which intrinsic neuronal excitability is modulated in the piriform cortex.

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    Cohen-Matsliah, Sivan I; Rosenblum, Kobi; Barkai, Edi

    2009-10-01

    Long-lasting modulation of intrinsic neuronal excitability in cortical neurons underlies distinct stages of skill learning. However, whether individual differences in learning capabilities are dependent on the rate by which such learning-induced modifications occur has yet to be explored. Here we show that training rats in a simple olfactory-discrimination task results in the same enhanced excitability in piriform cortex neurons as previously shown after training in a much more complex olfactory-discrimination task. Based on their learning capabilities in the simple task, rats could be divided to two groups: fast performers and slow performers. The rate at which rats accomplished the skill to perform the simple task was correlated with the time course at which piriform cortex neurons increased their repetitive spike firing. Twelve hours after learning, neurons from fast performers had reduced spike frequency adaptation as compared with neurons from slow performers and controls. Three days after learning, spike frequency adaptation was reduced in neurons from SP, while neurons from fast performers increased their spike firing adaptation to the level of controls. Accordingly, the post-burst AHP was reduced in neurons from fast performers 12 h after learning and in neurons from slow performers 3 days after learning. Moreover, the differences in learning capabilities between fast performers and slow performers were maintained when examined in a different, complex olfactory-discrimination task. We suggest that the rate at which neuronal excitability is modified during learning may affect the behavioral flexibility of the animal.

  6. Duration of the Unconditioned Stimulus in Appetitive Conditioning of Honeybees Differentially Impacts Learning, Long-Term Memory Strength, and the Underlying Protein Synthesis

    Science.gov (United States)

    Marter, Kathrin; Grauel, M. Katharina; Lewa, Carmen; Morgenstern, Laura; Buckemüller, Christina; Heufelder, Karin; Ganz, Marion; Eisenhardt, Dorothea

    2014-01-01

    This study examines the role of stimulus duration in learning and memory formation of honeybees ("Apis mellifera"). In classical appetitive conditioning honeybees learn the association between an initially neutral, conditioned stimulus (CS) and the occurrence of a meaningful stimulus, the unconditioned stimulus (US). Thereby the CS…

  7. Duration of the Unconditioned Stimulus in Appetitive Conditioning of Honeybees Differentially Impacts Learning, Long-Term Memory Strength, and the Underlying Protein Synthesis

    Science.gov (United States)

    Marter, Kathrin; Grauel, M. Katharina; Lewa, Carmen; Morgenstern, Laura; Buckemüller, Christina; Heufelder, Karin; Ganz, Marion; Eisenhardt, Dorothea

    2014-01-01

    This study examines the role of stimulus duration in learning and memory formation of honeybees ("Apis mellifera"). In classical appetitive conditioning honeybees learn the association between an initially neutral, conditioned stimulus (CS) and the occurrence of a meaningful stimulus, the unconditioned stimulus (US). Thereby the CS…

  8. Lateralization of gene expression in the honeybee brain during olfactory learning

    Science.gov (United States)

    Guo, Yu; Wang, Zilong; Li, You; Wei, Guifeng; Yuan, Jiao; Sun, Yu; Wang, Huan; Qin, Qiuhong; Zeng, Zhijiang; Zhang, Shaowu; Chen, Runsheng

    2016-01-01

    In the last decade, it has been demonstrated that brain functional asymmetry occurs not only in vertebrates but also in invertebrates. However, the mechanisms underlying functional asymmetry remain unclear. In the present study, we trained honeybees of the same parentage and age, on the proboscis extension reflex (PER) paradigm with only one antenna in use. The comparisons of gene expression between the left and right hemispheres were carried out using high throughput sequencing. Our research revealed that gene expression in the honeybee brain is also asymmetric, with more genes having higher expression in the right hemisphere than the left hemisphere. Our studies show that during olfactory learning, the left hemisphere is more responsible for long term memory and the right hemisphere is more responsible for the learning and short term memory. PMID:27703214

  9. Neuronal Nitric-Oxide Synthase Deficiency Impairs the Long-Term Memory of Olfactory Fear Learning and Increases Odor Generalization

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    Pavesi, Eloisa; Heldt, Scott A.; Fletcher, Max L.

    2013-01-01

    Experience-induced changes associated with odor learning are mediated by a number of signaling molecules, including nitric oxide (NO), which is predominantly synthesized by neuronal nitric oxide synthase (nNOS) in the brain. In the current study, we investigated the role of nNOS in the acquisition and retention of conditioned olfactory fear. Mice…

  10. Coincident activation of NMDA and dopamine D1 receptors within the nucleus accumbens core is required for appetitive instrumental learning.

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    Smith-Roe, S L; Kelley, A E

    2000-10-15

    The nucleus accumbens, a brain structure ideally situated to act as an interface between corticolimbic information-processing regions and motor output systems, is well known to subserve behaviors governed by natural reinforcers. In the accumbens core, glutamatergic input from its corticolimbic afferents and dopaminergic input from the ventral tegmental area converge onto common dendrites of the medium spiny neurons that populate the accumbens. We have previously found that blockade of NMDA receptors in the core with the antagonist 2-amino-5-phosphonopentanoic acid (AP-5; 5 nmol) abolishes acquisition but not performance of an appetitive instrumental learning task (Kelley et al., 1997). Because it is currently hypothesized that concurrent dopamine D(1) and glutamate receptor activation is required for long-term changes associated with plasticity, we wished to examine whether the dopamine system in the accumbens core modulates learning via NMDA receptors. Co-infusion of low doses of the D(1) receptor antagonist SCH-23390 (0.3 nmol) and AP-5 (0.5 nmol) into the accumbens core strongly impaired acquisition of instrumental learning (lever pressing for food), whereas when infused separately, these low doses had no effect. Infusion of the combined low doses had no effect on indices of feeding and motor activity, suggesting a specific effect on learning. We hypothesize that co-activation of NMDA and D(1) receptors in the nucleus accumbens core is a key process for acquisition of appetitive instrumental learning. Such an interaction is likely to promote intracellular events and gene regulation necessary for synaptic plasticity and is supported by a number of cellular models.

  11. Shared mushroom body circuits underlie visual and olfactory memories in Drosophila.

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    Vogt, Katrin; Schnaitmann, Christopher; Dylla, Kristina V; Knapek, Stephan; Aso, Yoshinori; Rubin, Gerald M; Tanimoto, Hiromu

    2014-08-19

    In nature, animals form memories associating reward or punishment with stimuli from different sensory modalities, such as smells and colors. It is unclear, however, how distinct sensory memories are processed in the brain. We established appetitive and aversive visual learning assays for Drosophila that are comparable to the widely used olfactory learning assays. These assays share critical features, such as reinforcing stimuli (sugar reward and electric shock punishment), and allow direct comparison of the cellular requirements for visual and olfactory memories. We found that the same subsets of dopamine neurons drive formation of both sensory memories. Furthermore, distinct yet partially overlapping subsets of mushroom body intrinsic neurons are required for visual and olfactory memories. Thus, our results suggest that distinct sensory memories are processed in a common brain center. Such centralization of related brain functions is an economical design that avoids the repetition of similar circuit motifs.

  12. Gilgamesh is required for rutabaga-independent olfactory learning in Drosophila.

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    Tan, Ying; Yu, Dinghui; Pletting, Jennifer; Davis, Ronald L

    2010-09-09

    Cyclic AMP signaling in Drosophila mushroom body neurons, anchored by the adenylyl cyclase encoded by the rutabaga gene, is indispensable for olfactory memory formation. From a screen for new memory mutants, we identified alleles of the gilgamesh (gish) gene, which encodes a casein kinase Iγ homolog that is preferentially expressed in the mushroom body neurons. The gish-encoded kinase participates in the physiology of these neurons underlying memory formation since the mutant memory deficit was rescued with expression of a gish cDNA in these neurons only during adulthood. A cellular memory trace, detected as increased calcium influx into the α'/β' neuron processes in response to the odor used for conditioning, was disrupted in gish mutants. Epistasis experiments indicated a lack of genetic interactions between gish and rutabaga. Therefore, gish participates in a rutabaga-independent pathway for memory formation and accounts for some of the residual learning that occurs in rutabaga mutants.

  13. Knockout crickets for the study of learning and memory: Dopamine receptor Dop1 mediates aversive but not appetitive reinforcement in crickets.

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    Awata, Hiroko; Watanabe, Takahito; Hamanaka, Yoshitaka; Mito, Taro; Noji, Sumihare; Mizunami, Makoto

    2015-11-02

    Elucidation of reinforcement mechanisms in associative learning is an important subject in neuroscience. In mammals, dopamine neurons are thought to play critical roles in mediating both appetitive and aversive reinforcement. Our pharmacological studies suggested that octopamine and dopamine neurons mediate reward and punishment, respectively, in crickets, but recent studies in fruit-flies concluded that dopamine neurons mediates both reward and punishment, via the type 1 dopamine receptor Dop1. To resolve the discrepancy between studies in different insect species, we produced Dop1 knockout crickets using the CRISPR/Cas9 system and found that they are defective in aversive learning with sodium chloride punishment but not appetitive learning with water or sucrose reward. The results suggest that dopamine and octopamine neurons mediate aversive and appetitive reinforcement, respectively, in crickets. We suggest unexpected diversity in neurotransmitters mediating appetitive reinforcement between crickets and fruit-flies, although the neurotransmitter mediating aversive reinforcement is conserved. This study demonstrates usefulness of the CRISPR/Cas9 system for producing knockout animals for the study of learning and memory.

  14. Aged neuronal nitric oxide knockout mice show preserved olfactory learning in both social recognition and odor-conditioning tasks

    Directory of Open Access Journals (Sweden)

    Bronwen M James

    2015-03-01

    Full Text Available There is evidence for both neurotoxic and neuroprotective roles of nitric oxide (NO in the brain and changes in the expression of the neuronal isoform of nitric oxide synthase (nNOS gene occur during aging. The current studies have investigated potential support for either a neurotoxic or neuroprotective role of NO derived from nNOS in the context of aging by comparing olfactory learning and locomotor function in young compared to old nNOS knockout (nNOS/- and wildtype control mice. Tasks involving social recognition and olfactory conditioning paradigms showed that old nNOS-/-animals had improved retention of learning compared to similar aged wildtype controls. Young nNOS-/- animals showed superior reversal learning to wildtypes in a conditioned learning task, although their performance was weakened with age. Interestingly, whereas young nNOS-/- animals were impaired in long term memory for social odors compared to wildtype controls, in old animals this pattern was reversed, possibly indicating beneficial compensatory changes influencing olfactory memory may occur during aging in nNOS-/- animals. Possibly such compensatory changes may have involved increased NO from other NOS isoforms since the memory deficit in young nNOS-/-animals could be rescued by the NO-donor, molsidomine. Both nNOS-/- and wildtype animals showed an age-associated decline in locomotor activity although young nNOS-/- animals were significantly more active than wildtypes, possibly due to an increased interest in novelty. Overall our findings suggest that lack of NO release via nNOS may protect animals to some extent against age-associated cognitive decline in memory tasks typically involving olfactory and hippocampal regions, but not against declines in reversal learning or locomotor activity.

  15. Transient inactivation of the pigeon hippocampus or the nidopallium caudolaterale during extinction learning impairs extinction retrieval in an appetitive conditioning paradigm.

    Science.gov (United States)

    Lengersdorf, Daniel; Stüttgen, Maik C; Uengoer, Metin; Güntürkün, Onur

    2014-05-15

    The majority of experiments exploring context-dependent extinction learning employ Pavlovian fear conditioning in rodents. Since mechanisms of appetitive and aversive learning are known to differ at the neuronal level, we sought to investigate extinction learning in an appetitive setting. Working with pigeons, we established a within-subject ABA renewal paradigm based on Rescorla (Q J Exp Psychol 61:1793) and combined it with pharmacological interventions during extinction. From the fear conditioning literature, it is known that both prefrontal cortex and the hippocampus are core structures for context-specific extinction learning. Accordingly, we transiently inactivated the nidopallium caudolaterale (NCL, a functional analogue of mammalian prefrontal cortex) and the hippocampus in separate experiments by intracranial infusion of the sodium-channel blocker tetrodotoxin immediately before extinction training. We find that TTX in both structures non-specifically suppresses conditioned responding, as revealed by a reduction of response rate to both the extinguished conditioned stimulus and a control stimulus which remained reinforced throughout the experiment. Furthermore, TTX during extinction training impaired later extinction retrieval assessed under drug-free conditions. This was true when responding to the extinguished stimulus was assessed in the context of extinction but not when tested in the context of acquisition, although both contexts were matched with respect to their history of conditioning. These results indicate that both NCL and hippocampus are involved in extinction learning under appetitive conditions or, more specifically, in the consolidation of extinction memory, and that their contribution to extinction is context-specific.

  16. Exposure to multiple cholinergic pesticides impairs olfactory learning and memory in honeybees.

    Science.gov (United States)

    Williamson, Sally M; Wright, Geraldine A

    2013-05-15

    Pesticides are important agricultural tools often used in combination to avoid resistance in target pest species, but there is growing concern that their widespread use contributes to the decline of pollinator populations. Pollinators perform sophisticated behaviours while foraging that require them to learn and remember floral traits associated with food, but we know relatively little about the way that combined exposure to multiple pesticides affects neural function and behaviour. The experiments reported here show that prolonged exposure to field-realistic concentrations of the neonicotinoid imidacloprid and the organophosphate acetylcholinesterase inhibitor coumaphos and their combination impairs olfactory learning and memory formation in the honeybee. Using a method for classical conditioning of proboscis extension, honeybees were trained in either a massed or spaced conditioning protocol to examine how these pesticides affected performance during learning and short- and long-term memory tasks. We found that bees exposed to imidacloprid, coumaphos, or a combination of these compounds, were less likely to express conditioned proboscis extension towards an odor associated with reward. Bees exposed to imidacloprid were less likely to form a long-term memory, whereas bees exposed to coumaphos were only less likely to respond during the short-term memory test after massed conditioning. Imidacloprid, coumaphos and a combination of the two compounds impaired the bees' ability to differentiate the conditioned odour from a novel odour during the memory test. Our results demonstrate that exposure to sublethal doses of combined cholinergic pesticides significantly impairs important behaviours involved in foraging, implying that pollinator population decline could be the result of a failure of neural function of bees exposed to pesticides in agricultural landscapes.

  17. Parallel olfactory processing in the honey bee brain: odor learning and generalization under selective lesion of a projection neuron tract

    Directory of Open Access Journals (Sweden)

    Julie eCarcaud

    2016-01-01

    Full Text Available The function of parallel neural processing is a fundamental problem in Neuroscience, as it is found across sensory modalities and evolutionary lineages, from insects to humans. Recently, parallel processing has attracted increased attention in the olfactory domain, with the demonstration in both insects and mammals that different populations of second-order neurons encode and/or process odorant information differently. Among insects, Hymenoptera present a striking olfactory system with a clear neural dichotomy from the periphery to higher-order centers, based on two main tracts of second-order (projection neurons: the medial and lateral antennal lobe tracts (m-ALT and l-ALT. To unravel the functional role of these two pathways, we combined specific lesions of the m-ALT tract with behavioral experiments, using the classical conditioning of the proboscis extension response (PER conditioning. Lesioned and intact bees had to learn to associate an odorant (1-nonanol with sucrose. Then the bees were subjected to a generalization procedure with a range of odorants differing in terms of their carbon chain length or functional group. We show that m-ALT lesion strongly affects acquisition of an odor-sucrose association. However, lesioned bees that still learned the association showed a normal gradient of decreasing generalization responses to increasingly dissimilar odorants. Generalization responses could be predicted to some extent by in vivo calcium imaging recordings of l-ALT neurons. The m-ALT pathway therefore seems necessary for normal classical olfactory conditioning performance.

  18. Parallel Olfactory Processing in the Honey Bee Brain: Odor Learning and Generalization under Selective Lesion of a Projection Neuron Tract.

    Science.gov (United States)

    Carcaud, Julie; Giurfa, Martin; Sandoz, Jean Christophe

    2015-01-01

    The function of parallel neural processing is a fundamental problem in Neuroscience, as it is found across sensory modalities and evolutionary lineages, from insects to humans. Recently, parallel processing has attracted increased attention in the olfactory domain, with the demonstration in both insects and mammals that different populations of second-order neurons encode and/or process odorant information differently. Among insects, Hymenoptera present a striking olfactory system with a clear neural dichotomy from the periphery to higher-order centers, based on two main tracts of second-order (projection) neurons: the medial and lateral antennal lobe tracts (m-ALT and l-ALT). To unravel the functional role of these two pathways, we combined specific lesions of the m-ALT tract with behavioral experiments, using the classical conditioning of the proboscis extension response (PER conditioning). Lesioned and intact bees had to learn to associate an odorant (1-nonanol) with sucrose. Then the bees were subjected to a generalization procedure with a range of odorants differing in terms of their carbon chain length or functional group. We show that m-ALT lesion strongly affects acquisition of an odor-sucrose association. However, lesioned bees that still learned the association showed a normal gradient of decreasing generalization responses to increasingly dissimilar odorants. Generalization responses could be predicted to some extent by in vivo calcium imaging recordings of l-ALT neurons. The m-ALT pathway therefore seems necessary for normal classical olfactory conditioning performance.

  19. Intertrial intervals and contextual conditioning in appetitive pavlovian learning: effects over the ABA renewal paradigm.

    Science.gov (United States)

    Carranza-Jasso, Rodrigo; Urcelay, Gonzalo P; Nieto, Javier; Sánchez-Carrasco, Livia

    2014-09-01

    Three experiments using rats in an appetitive conditioning procedure analyzed the effect of short and long (50s vs. 1440s) intertrial intervals (ITI) over the acquisition of conditioned stimulus (CS), context (Ctxt), and unconditioned stimulus (US) associations, as well as the effect on the extinction and renewal of the conditioned response to the CS. Experiment 1 revealed more contextual conditioned responses in groups trained with the short ITIs, however the renewal effect was not observed during test phase with either ITI condition. When subjects were pre-exposed to the contexts before the acquisition phase (Experiment 2) renewal of the conditioned response (CR) was only observed in long ITI group. However, when the acquisition context was extinguished (Experiment 3) the renewal effect observed in the Experiment 2 was weakened. In all three experiments subjects showed a similar number of responses to the tone predicting food, however they showed a clear contextual conditioning effect only for the groups trained with short ITIs. It is noteworthy that the acquisition context showed high levels of the CR in the renewal test only for groups trained with short ITIs (Experiment 2) but these responses were absent if additional contextual extinction was imposed before such test (Experiment 3). In general, all groups showed similar acquisition curves for the CS but only Short groups had an increase in the CR during the pre-CS. Also, context conditioning does not interfere with the conditioning of the CS and context pre-exposure prior to acquisition is essential in order to observe the renewal effect when long ITIs are used.

  20. Roles of octopaminergic and dopaminergic neurons in mediating reward and punishment signals in insect visual learning.

    Science.gov (United States)

    Unoki, Sae; Matsumoto, Yukihisa; Mizunami, Makoto

    2006-10-01

    Insects, like vertebrates, have considerable ability to associate visual, olfactory or other sensory signals with reward or punishment. Previous studies in crickets, honey bees and fruit-flies have suggested that octopamine (OA, invertebrate counterpart of noradrenaline) and dopamine (DA) mediate various kinds of reward and punishment signals in olfactory learning. However, whether the roles of OA and DA in mediating positive and negative reinforcing signals can be generalized to learning of sensory signals other than odors remained unknown. Here we first established a visual learning paradigm in which to associate a visual pattern with water reward or saline punishment for crickets and found that memory after aversive conditioning decayed much faster than that after appetitive conditioning. Then, we pharmacologically studied the roles of OA and DA in appetitive and aversive forms of visual learning. Crickets injected with epinastine or mianserin, OA receptor antagonists, into the hemolymph exhibited a complete impairment of appetitive learning to associate a visual pattern with water reward, but aversive learning with saline punishment was unaffected. By contrast, fluphenazine, chlorpromazine or spiperone, DA receptor antagonists, completely impaired aversive learning without affecting appetitive learning. The results demonstrate that OA and DA participate in reward and punishment conditioning in visual learning. This finding, together with results of previous studies on the roles of OA and DA in olfactory learning, suggests ubiquitous roles of the octopaminergic reward system and dopaminergic punishment system in insect learning.

  1. Restless led syndrome model Drosophila melanogaster show successful olfactory learning and 1-day retention of the acquired memory

    Directory of Open Access Journals (Sweden)

    Mika F. Asaba

    2013-09-01

    Full Text Available Restless Legs Syndrome (RLS is a prevalent but poorly understood disorder that ischaracterized by uncontrollable movements during sleep, resulting in sleep disturbance.Olfactory memory in Drosophila melanogaster has proven to be a useful tool for the study ofcognitive deficits caused by sleep disturbances, such as those seen in RLS. A recently generatedDrosophila model of RLS exhibited disturbed sleep patterns similar to those seen in humans withRLS. This research seeks to improve understanding of the relationship between cognitivefunctioning and sleep disturbances in a new model for RLS. Here, we tested learning andmemory in wild type and dBTBD9 mutant flies by Pavlovian olfactory conditioning, duringwhich a shock was paired with one of two odors. Flies were then placed in a T-maze with oneodor on either side, and successful associative learning was recorded when the flies chose theside with the unpaired odor. We hypothesized that due to disrupted sleep patterns, dBTBD9mutant flies would be unable to learn the shock-odor association. However, the current studyreports that the recently generated Drosophila model of RLS shows successful olfactorylearning, despite disturbed sleep patterns, with learning performance levels matching or betterthan wild type flies.

  2. Pheromone signal transduction in humans: what can be learned from olfactory loss.

    Science.gov (United States)

    Savic, Ivanka; Hedén-Blomqvist, Ebba; Berglund, Hans

    2009-09-01

    Because humans seem to lack neuronal elements in the vomeronasal organ (VNO), many scientists believe that humans are unable to detect pheromones. This view is challenged by the observations that pheromone-like compounds, 4,16-androstadien-3-one (AND) and oestra-1,3,5(10),16-tetraen-3-ol (EST), activate the human hypothalamus. Whether these activations are mediated via VNO, venous blood or olfactory mucosa is presently unknown. To disentangle between the three alternatives, we conducted activation studies in 12 heterosexual males with chronic anosmia because of nasal polyps. Polyposis hampers signal transduction via the olfactory mucosa without interfering with the VNO or the pheromone transport via venous blood. Twelve healthy men served as controls. Subjects were investigated with (15)O-H(2)O PET during smelling of odorless air (base line), AND, EST, vanillin, and acetone. Smelling of EST activated the anterior hypothalamus in controls, but not anosmics. Neither did the anosmics display cerebral activations with AND or vanillin. Clusters were detected only with the trigeminal odorant acetone, and only in the thalamus, brainstem, the anterior cingulate, and parts of the sensorimotor cortex. Direct comparisons with controls (controls-anosmics) showed clusters in the olfactory cortex (amygdala and piriform cortex) with AND, vanillin, and acetone, and in the anterior hypothalamus with EST. The observed absence of olfactory and presence of trigeminal activations in anosmics indicates that polyposis primarily affected signal processing via the olfactory mucosa. The anosmics inability to activate the hypothalamus with EST, therefore, suggests that in healthy men EST signals were primarily transmitted via the olfactory system.

  3. A role for the anterior piriform cortex in early odor preference learning: evidence for multiple olfactory learning structures in the rat pup.

    Science.gov (United States)

    Morrison, Gillian L; Fontaine, Christine J; Harley, Carolyn W; Yuan, Qi

    2013-07-01

    cFos activation in the anterior piriform cortex (aPC) occurs in early odor preference learning in rat pups (Roth and Sullivan 2005). Here we provide evidence that the pairing of odor as a conditioned stimulus and β-adrenergic activation in the aPC as an unconditioned stimulus generates early odor preference learning. β-Adrenergic blockade in the aPC prevents normal preference learning. Enhancement of aPC cAMP response element-binding protein (CREB) phosphorylation in trained hemispheres is consistent with a role for this cascade in early odor preference learning in the aPC. In vitro experiments suggested theta-burst-mediated long-term potentiation (LTP) at the lateral olfactory tract (LOT) to aPC synapse depends on N-methyl-D-aspartate (NMDA) receptors and can be significantly enhanced by β-adrenoceptor activation, which causes increased glutamate release from LOT synapses during LTP induction. NMDA receptors in aPC are also shown to be critical for the acquisition, but not expression, of odor preference learning, as would be predicted if they mediate initial β-adrenoceptor-promoted aPC plasticity. Ex vivo experiments 3 and 24 h after odor preference training reveal an enhanced LOT-aPC field excitatory postsynaptic potential (EPSP). At 3 h both presynaptic and postsynaptic potentiations support EPSP enhancement while at 24 h only postsynaptic potentiation is seen. LOT-LTP in aPC is excluded by odor preference training. Taken together with earlier work on the role of the olfactory bulb in early odor preference learning, these outcomes suggest early odor preference learning is normally supported by and requires multiple plastic changes at least at two levels of olfactory circuitry.

  4. Appetitively motivated instrumental learning in SynGAP heterozygous knockout mice.

    Science.gov (United States)

    Muhia, Mary; Feldon, Joram; Knuesel, Irene; Yee, Benjamin K

    2009-10-01

    The synaptic Ras/Rap-GTPase-activating protein (SynGAP) regulates specific intracellular events following N-methyl-d-aspartate receptor (NMDAR) activation. Here, the impact of SynGAP heterozygous knockout (SG+/-) on NMDAR-dependent functions was assessed using different positive reinforcement schedules in instrumental conditioning. The knockout did not affect the temporal control of operant responding under a fixed interval (FI) schedule, but led to a putative enhancement in response vigor and/or disinhibition. When examined on differential reinforcement of low rates of response (DRL) schedules, SG+/- mice showed increased responding under DRL-4s and DRL-8s, without impairing the response efficiency (total rewards/total lever presses) because both rewarded and nonrewarded presses were elevated. Motivation was unaffected as evaluated using a progressive ratio (PR) schedule. Yet, SG+/- mice persisted in responding during extinction at the end of PR training, although an equivalent phenotype was not evident in extinction learning following FI-20s training. This extinction phenotype is therefore schedule-specific and cannot be generalized to Pavlovian conditioning. In conclusion, constitutive SynGAP reduction increases vigor in the execution of learned operant behavior without compromising its temporal control, yielding effects readily distinguishable from NMDAR blockade.

  5. Noradrenergic Control of Odor Recognition in a Nonassociative Olfactory Learning Task in the Mouse

    Science.gov (United States)

    Veyrac, Alexandra; Nguyen, Veronique; Marien, Marc; Didier, Anne; Jourdan, Francois

    2007-01-01

    The present study examined the influence of pharmacological modulations of the locus coeruleus noradrenergic system on odor recognition in the mouse. Mice exposed to a nonrewarded olfactory stimulation (training) were able to memorize this odor and to discriminate it from a new odor in a recall test performed 15 min later. At longer delays (30 or…

  6. Olfactory guidance of nipple attachment and suckling in kittens of the domestic cat: Inborn and learned responses.

    Science.gov (United States)

    Raihani, Gina; González, Daniel; Arteaga, Lourdes; Hudson, Robyn

    2009-12-01

    In 60 kittens (11 litters) from free-ranging domestic cats we investigated the role of chemical cues in facilitating nipple attachment and suckling during the first month of postnatal life when kittens are totally dependent on the mother's milk. Kittens were tested both together and individually on sedated females in different reproductive states. We found (1) that newborn kittens with no suckling experience responded to the ventrum of lactating but not to the ventrum of nonlactating females with search behavior and attached to nipples within minutes; (2) that even in older kittens, nipple attachment depended on females' reproductive state, with virtually no attachments on nonreproducing females, some on pregnant females, the greatest number on early-lactating females, followed by a decline on late-lactating females; and (3) that kittens could locate their particular, most used nipple on their mother but not on a female of similar lactational age, even after eye opening. We suggest that kittens respond from birth with efficient nipple-search behavior to inborn olfactory cues on the mother's ventrum, that emission of these is under hormonal control, but that kittens also quickly learn olfactory cues specific to their own mother and to their own particular nipples.

  7. The FVB/N mice: A well suited strain to study learning and memory processes using olfactory cues.

    Science.gov (United States)

    Girard, Stéphane D; Escoffier, Guy; Khrestchatisky, Michel; Roman, François S

    2016-01-01

    The FVB/N mice are well suited to generate transgenic animals. These mice are also particularly sensitive to seizures and neurodegeneration induced by systemic administration of chemoconvulsants and are very useful to model epilepsy. However, previous studies report strong cognitive and visual impairments suggesting this background unsuitable for behavioral analysis. In this study, we assessed and compared learning abilities of FVB/N mice to the well characterized C57BL/6 strain using the olfactory tubing maze, a non-visual hippocampus-dependent task in which the mice were trained to learn odor-reward associations. Exploratory behavior and spontaneous locomotor activity were then compared using the open field test. We demonstrated that FVB/N mice were able to learn the task, reaching at the end of the test a high percentage of correct responses. Interestingly, the performance of the FVB/N mice was at least similar to that of the C57BL/6 mice. Moreover, in contrast to previous reports, the FVB/N mice displayed a spontaneous locomotor activity lower than C57BL/6 mice. Our study demonstrated that FVB/N mice are not cognitively impaired and that their learning and memory performance can be assessed when the task is based on olfaction rather than vision.

  8. Associative learning for danger avoidance nullifies innate positive chemotaxis to host olfactory stimuli in a parasitic wasp.

    Science.gov (United States)

    Benelli, Giovanni; Stefanini, Cesare; Giunti, Giulia; Geri, Serena; Messing, Russell H; Canale, Angelo

    2014-09-01

    Animals rely on associative learning for a wide range of purposes, including danger avoidance. This has been demonstrated for several insects, including cockroaches, mosquitoes, drosophilid flies, paper wasps, stingless bees, bumblebees and honeybees, but less is known for parasitic wasps. We tested the ability of Psyttalia concolor (Hymenoptera: Braconidae) females to associate different dosages of two innately attractive host-induced plant volatiles (HIPVs), ethyl octanoate and decanal, with danger (electric shocks). We conducted an associative treatment involving odours and shocks and two non-associative controls involving shocks but not odours and odours but not shocks. In shock-only and odour-only trained wasps, females preferred on HIPV-treated than on blank discs. In associative-trained wasps, however, P. concolor's innate positive chemotaxis for HIPVs was nullified (lowest HIPV dosage tested) or reversed (highest HIPV dosage tested). This is the first report of associative learning of olfactory cues for danger avoidance in parasitic wasps, showing that the effects of learning can override innate positive chemotaxes.

  9. Associative learning for danger avoidance nullifies innate positive chemotaxis to host olfactory stimuli in a parasitic wasp

    Science.gov (United States)

    Benelli, Giovanni; Stefanini, Cesare; Giunti, Giulia; Geri, Serena; Messing, Russell H.; Canale, Angelo

    2014-09-01

    Animals rely on associative learning for a wide range of purposes, including danger avoidance. This has been demonstrated for several insects, including cockroaches, mosquitoes, drosophilid flies, paper wasps, stingless bees, bumblebees and honeybees, but less is known for parasitic wasps. We tested the ability of Psyttalia concolor (Hymenoptera: Braconidae) females to associate different dosages of two innately attractive host-induced plant volatiles (HIPVs), ethyl octanoate and decanal, with danger (electric shocks). We conducted an associative treatment involving odours and shocks and two non-associative controls involving shocks but not odours and odours but not shocks. In shock-only and odour-only trained wasps, females preferred on HIPV-treated than on blank discs. In associative-trained wasps, however, P. concolor's innate positive chemotaxis for HIPVs was nullified (lowest HIPV dosage tested) or reversed (highest HIPV dosage tested). This is the first report of associative learning of olfactory cues for danger avoidance in parasitic wasps, showing that the effects of learning can override innate positive chemotaxes.

  10. Learning through the waste: olfactory cues from the colony refuse influence plant preferences in foraging leaf-cutting ants.

    Science.gov (United States)

    Arenas, Andrés; Roces, Flavio

    2016-08-15

    Leaf-cutting ants learn to avoid plants initially harvested if they prove to be harmful for their symbiotic fungus once incorporated into the nest. At this point, waste particles removed from the fungus garden are likely to contain cues originating from both the unsuitable plant and the damaged fungus. We investigated whether leaf-cutting ant foragers learn to avoid unsuitable plants solely through the colony waste. We fed subcolonies of Acromymex ambiguus privet leaves treated with a fungicide undetectable to the ants, then collected the produced waste, and placed it into the fungus chamber of naive subcolonies. In individual choice tests, naive foragers preferred privet leaves before waste was put into the fungus chamber, but avoided them afterwards. Evidence on the influence of olfactory cues from the waste on decision making by foragers was obtained by scenting and transferring waste particles from subcolonies that had been fed either fungicide-treated or untreated leaves. In choice experiments, foragers from subcolonies given scented waste originating from fungicide-treated leaves collected fewer sugared paper discs with that scent compared with foragers from subcolonies given scented waste from untreated leaves. The results indicate that foragers learn to avoid plants unsuitable for the fungus by associating plant odours and cues from the damaged fungus that are present in waste particles. It is argued that waste particles may contribute to spread information about noxious plants for the fungus within the colony. © 2016. Published by The Company of Biologists Ltd.

  11. Central regulation of sodium appetite.

    Science.gov (United States)

    Geerling, Joel C; Loewy, Arthur D

    2008-02-01

    Sodium appetite, the behavioural drive to ingest salt, is stimulated by prolonged physiological sodium deficiency in many animal species. The same neural mechanisms that are responsible for sodium appetite in laboratory animals may influence human behaviour as well, with particular relevance to the dietary salt intake of patients with diseases such as heart failure, renal failure, liver failure and salt-sensitive hypertension. Since the original experimental work of Curt Richter in the 1930s, much has been learned about the regulation of salt-ingestive behaviour. Here, we review data from physiology, pharmacology, neuroanatomy and neurobehavioural investigations into the stimulatory and inhibitory signals that regulate sodium appetite. A rudimentary framework is proposed for the brain circuits that integrate peripheral information representing the need for sodium with neural signals for the gustatory detection of salt in order to drive a motivated ingestive response. Based on this model, areas of remaining uncertainty are highlighted where future information would allow a more detailed understanding of the neural circuitry responsible for sodium appetite.

  12. Physiological expression of olfactory discrimination rule learning balances whole-population modulation and circuit stability in the piriform cortex network.

    Science.gov (United States)

    Jammal, Luna; Whalley, Ben; Ghosh, Sourav; Lamrecht, Raphael; Barkai, Edi

    2016-07-01

    Once trained, rats are able to execute particularly difficult olfactory discrimination tasks with exceptional accuracy. Such skill acquisition, termed "rule learning", is accompanied by a series of long-lasting modifications to three cellular properties which modulate pyramidal neuron activity in piriform cortex; intrinsic excitability, synaptic excitation, and synaptic inhibition. Here, we explore how these changes, which are seemingly contradictory at the single-cell level in terms of their effect on neuronal excitation, are manifested within the piriform cortical neuronal network to store the memory of the rule, while maintaining network stability. To this end, we monitored network activity via multisite extracellular recordings of field postsynaptic potentials (fPSPS) and with single-cell recordings of miniature inhibitory and excitatory synaptic events in piriform cortex slices. We show that although 5 days after rule learning the cortical network maintains its basic activity patterns, synaptic connectivity is strengthened specifically between spatially proximal cells. Moreover, while the enhancement of inhibitory and excitatory synaptic connectivity is nearly identical, strengthening of synaptic inhibition is equally distributed between neurons while synaptic excitation is particularly strengthened within a specific subgroup of cells. We suggest that memory for the acquired rule is stored mainly by strengthening excitatory synaptic connection between close pyramidal neurons and runaway synaptic activity arising from this change is prevented by a nonspecific enhancement of synaptic inhibition.

  13. Color Modulates Olfactory Learning in Honeybees by an Occasion-Setting Mechanism

    Science.gov (United States)

    Mota, Theo; Giurfa, Martin; Sandoz, Jean-Christophe

    2011-01-01

    A sophisticated form of nonelemental learning is provided by occasion setting. In this paradigm, animals learn to disambiguate an uncertain conditioned stimulus using alternative stimuli that do not enter into direct association with the unconditioned stimulus. For instance, animals may learn to discriminate odor rewarded from odor nonrewarded…

  14. Learning about the functions of the olfactory system from people without a sense of smell.

    Directory of Open Access Journals (Sweden)

    Ilona Croy

    Full Text Available The olfactory system provides numerous functions to humans, influencing ingestive behavior, awareness of environmental hazards and social communication. Approximately 1/5 of the general population exhibit an impaired sense of smell. However, in contrast to the many affected, only few patients complain of their impairment. So how important is it for humans to have an intact sense of smell? Or is it even dispensable, at least in the Western world? To investigate this, we compared 32 patients, who were born without a sense of smell (isolated congenital anosmia--ICA with 36 age-matched controls. A broad questionnaire was used, containing domains relevant to olfaction in daily life, along with a questionnaire about social relationships and the BDI-questionnaire. ICA-patients differed only slightly from controls in functions of daily life related to olfaction. These differences included enhanced social insecurity, increased risk for depressive symptoms and increased risk for household accidents. In these domains the sense of olfaction seems to play a key role.

  15. Genetic Dissection of Aversive Associative Olfactory Learning and Memory in Drosophila Larvae.

    Directory of Open Access Journals (Sweden)

    Annekathrin Widmann

    2016-10-01

    Full Text Available Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult Drosophila it was shown that memory formation after aversive Pavlovian conditioning includes-besides other forms-a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches. Compared to adult Drosophila, memory formation was only sporadically analyzed at its larval stage. Here we deconstruct the larval mnemonic organization after aversive olfactory conditioning. We show that after odor-high salt conditioning larvae form two parallel memory phases; a short lasting component that depends on cyclic adenosine 3'5'-monophosphate (cAMP signaling and synapsin gene function. In addition, we show for the first time for Drosophila larvae an anesthesia resistant component, which relies on radish and bruchpilot gene function, protein kinase C activity, requires presynaptic output of mushroom body Kenyon cells and dopamine function. Given the numerical simplicity of the larval nervous system this work offers a unique prospect for studying memory formation of defined specifications, at full-brain scope with single-cell, and single-synapse resolution.

  16. Learning about the functions of the olfactory system from people without a sense of smell.

    Science.gov (United States)

    Croy, Ilona; Negoias, Simona; Novakova, Lenka; Landis, Basile N; Hummel, Thomas

    2012-01-01

    The olfactory system provides numerous functions to humans, influencing ingestive behavior, awareness of environmental hazards and social communication. Approximately 1/5 of the general population exhibit an impaired sense of smell. However, in contrast to the many affected, only few patients complain of their impairment. So how important is it for humans to have an intact sense of smell? Or is it even dispensable, at least in the Western world? To investigate this, we compared 32 patients, who were born without a sense of smell (isolated congenital anosmia--ICA) with 36 age-matched controls. A broad questionnaire was used, containing domains relevant to olfaction in daily life, along with a questionnaire about social relationships and the BDI-questionnaire. ICA-patients differed only slightly from controls in functions of daily life related to olfaction. These differences included enhanced social insecurity, increased risk for depressive symptoms and increased risk for household accidents. In these domains the sense of olfaction seems to play a key role.

  17. Appetite in the brain

    NARCIS (Netherlands)

    Smeets, P.A.M.

    2013-01-01

    Appetite is defined as ‘a natural desire to satisfy a bodily need, especially for food’. The counterpart of appetite is satiety, which is the state of satisfaction that follows after the need for food is fulfilled. However, palatable food can be appetizing in the absence of hunger and people may eng

  18. The GABAergic Anterior Paired Lateral Neurons Facilitate Olfactory Reversal Learning in "Drosophila"

    Science.gov (United States)

    Wu, Yanying; Ren, Qingzhong; Li, Hao; Guo, Aike

    2012-01-01

    Reversal learning has been widely used to probe the implementation of cognitive flexibility in the brain. Previous studies in monkeys identified an essential role of the orbitofrontal cortex (OFC) in reversal learning. However, the underlying circuits and molecular mechanisms are poorly understood. Here, we use the T-maze to investigate the neural…

  19. The GABAergic Anterior Paired Lateral Neurons Facilitate Olfactory Reversal Learning in "Drosophila"

    Science.gov (United States)

    Wu, Yanying; Ren, Qingzhong; Li, Hao; Guo, Aike

    2012-01-01

    Reversal learning has been widely used to probe the implementation of cognitive flexibility in the brain. Previous studies in monkeys identified an essential role of the orbitofrontal cortex (OFC) in reversal learning. However, the underlying circuits and molecular mechanisms are poorly understood. Here, we use the T-maze to investigate the neural…

  20. Neural correlates of olfactory learning paradigms in an identified neuron in the honeybee brain.

    Science.gov (United States)

    Mauelshagen, J

    1993-02-01

    conditioning procedure reveal that the effect observed for the one-trial conditioning paradigm is of an associative nature and that there might be modulations, which are specific for single and multiple trial conditioning procedures. It is hypothesized that the PE1-neuron is a possible element involved in the short-term acquisition, rather than in the long-term storage, of an associative olfactory memory in the honeybee.

  1. Complexity and competition in appetitive and aversive neural circuits

    Directory of Open Access Journals (Sweden)

    Crista L. Barberini

    2012-11-01

    Full Text Available Decision-making often involves using sensory cues to predict possible rewarding or punishing reinforcement outcomes before selecting a course of action. Recent work has revealed complexity in how the brain learns to predict rewards and punishments. Analysis of neural signaling during and after learning in the amygdala and orbitofrontal cortex, two brain areas that process appetitive and aversive stimuli, reveals a dynamic relationship between appetitive and aversive circuits. Specifically, the relationship between signaling in appetitive and aversive circuits in these areas shifts as a function of learning. Furthermore, although appetitive and aversive circuits may often drive opposite behaviors – approaching or avoiding reinforcement depending upon its valence – these circuits can also drive similar behaviors, such as enhanced arousal or attention; these processes also may influence choice behavior. These data highlight the formidable challenges ahead in dissecting how appetitive and aversive neural circuits interact to produce a complex and nuanced range of behaviors.

  2. CNS regulation of appetite.

    Science.gov (United States)

    Harrold, Joanne A; Dovey, Terry M; Blundell, John E; Halford, Jason C G

    2012-07-01

    This article reviews the regulation of appetite from a biopsychological perspective. It considers psychological experiences and peripheral nutritional systems (both episodic and tonic) and addresses their relationship with the CNS networks that process and integrate their input. Whilst such regulatory aspects of obesity focus on homeostatic control mechanisms, in the modern environment hedonic aspects of appetite are also critical. Enhanced knowledge of the complexity of appetite regulation and the mechanisms that sustain obesity indicate the challenge presented by management of the obesity epidemic. Nonetheless, effective control of appetite expression remains a critical therapeutic target for weight management. Currently, strategies which utilise a combination of agents to target both homeostatic and hedonic control mechanisms represent the most promising approaches. This article is part of a Special Issue entitled 'Central Control of Food Intake'. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Orientation in birds. Olfactory navigation.

    Science.gov (United States)

    Papi, F

    1991-01-01

    Research work on the olfactory navigation of birds, which has only recently attracted attention, has shown that many wild species rely on an osmotactic mechanism to find food sources, even at a considerable distance. The homing pigeon, the only bird to have been thoroughly investigated with respect to olfactory navigation, has been found to rely on local odours for homeward orientation, and to integrate olfactory cues perceived during passive transportation with those picked up at the release site. It is possible to design experiments in which birds are given false olfactory information, and predictions about the effects of this can be made and tested. Pigeons are able to home from unfamiliar sites because they acquire an olfactory map extending beyond the area they have flown over. The olfactory map is built up by associating wind-borne odours with the direction from which they come; this was shown by experiments which aimed to prevent, limit or alter this association. One aim of the research work has been to test whether pigeons flying over unfamiliar areas also rely or can learn to rely on non-olfactory cues, depending on their local availability, and/or on the methods of rearing and training applied to them. Various evaluations have been made of the results; the most recent experiments, however, confirm that pigeons do derive directional information from atmospheric odours. A neurobiological approach is also in progress; its results show that some telencephalic areas are involved in orientation and olfactory navigation. The lack of any knowledge about the distribution and chemical nature of the odorants which allow pigeons to navigate hinders progress in this area of research.

  4. Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"

    Science.gov (United States)

    Amano, Hisayuki; Maruyama, Ichiro N.

    2011-01-01

    The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH…

  5. Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"

    Science.gov (United States)

    Amano, Hisayuki; Maruyama, Ichiro N.

    2011-01-01

    The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH…

  6. Dissection of appetitive conditioning. Does impulsivity play a role?

    Science.gov (United States)

    Papachristou, Harilaos; Nederkoorn, Chantal; Beunen, Shalana; Jansen, Anita

    2013-10-01

    It is generally assumed that cue-reactivity results from appetitive pavlovian learning. This is the reason for applying cue exposure with response prevention interventions in the treatment of substance and eating disorders. However, not all appetitive conditioned responses are equally sensitive to extinction. Additionally, impulsivity traits appear to moderate cue-reactivity. Nevertheless, there has been little research on the role of impulsivity traits in the learning of different appetitive response systems. The purpose of the present study was (i) to replicate Van Gucht et al.'s (2010) findings, in particular, the acquisition and the differential extinction of appetitive learned responses and ii) to investigate the role of impulsivity traits in appetitive learning. Participants (n=50) took part in a single laboratory session. Impulsivity traits (reward sensitivity, response inhibition, sensation seeking) were measured at the beginning of the session. A paradigm similar to Van Gucht et al.'s (2010) was used for the acquisition and extinction of subjective conditioned responses for milk chocolate (craving, expectancy, and liking). The acquisition of appetitive responses was successful. Unlike craving and liking, the extinction of expectancy was fully successful. Impulsivity traits played no role in the acquisition and extinction of appetitive conditioning. The results support the differential sensitivity of different appetitive response systems to extinction. The lack of findings for the role of impulsivity traits in appetitive learning shows that the question of how impulsivity affects appetitive behaviour still remains open. Theoretical and methodological issues and clinical implications of the findings are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Appetitive-aversive interactions in Pavlovian fear conditioning.

    Science.gov (United States)

    Nasser, Helen M; McNally, Gavan P

    2012-06-01

    The existence of value coding and salience coding neurons in the mammalian brain, including in habenula and ventral tegmental area, has sparked considerable interest in the interactions that occur between Pavlovian appetitive and aversive conditioning. Here we studied these appetitive-aversive interactions at the behavioral level by assessing the learning that occurs when a Pavlovian appetitive conditioned stimulus (conditional stimulus, CS) serves as a CS for shock in Pavlovian fear conditioning. A Pavlovian appetitive CS was retarded in the rate at which it could be transformed into a fear CS (counterconditioning), but the presence of the appetitive CS augmented fear learning to a concurrently presented neutral CS (superconditioning). Retardation of fear learning was not alleviated by manipulations designed to restore the associability of the appetitive CS before fear conditioning but was alleviated by manipulations designed to increase the aversive quality of the shock unconditioned stimulus (US). These findings are consistent with opponent interactions between the appetitive and aversive motivational systems and provide a behavioral approach for assessing the neural correlates of these appetitive-aversive interactions.

  8. Appetitive vs. Aversive Conditioning in Humans

    Directory of Open Access Journals (Sweden)

    Marta eAndreatta

    2015-05-01

    Full Text Available In classical conditioning, an initially neutral stimulus (conditioned stimulus, CS becomes associated with a biologically salient event (unconditioned stimulus, US, which might be pain (aversive conditioning or food (appetitive conditioning. After a few associations, the CS is able to initiate either defensive or consummatory responses, respectively. Contrary to aversive conditioning, appetitive conditioning is rarely investigated in humans, although its importance for normal and pathological behaviors (e.g., obesity, addiction is undeniable. The present study intents to translate animal findings on appetitive conditioning to humans using food as an US. Thirty-three participants were investigated between 8 am and 10 am without breakfast in order to assure that they felt hungry. During two acquisition phases, one geometrical shape (avCS+ predicted an aversive US (painful electric shock, another shape (appCS+ predicted an appetitive US (chocolate or salty pretzel according to the participants’ preference, and a third shape (CS- predicted neither US. In an extinction phase, these three shapes plus a novel shape (NEW were presented again without US delivery. Valence and arousal ratings as well as startle and skin conductance (SCR responses were collected as learning indices. We found successful aversive and appetitive conditioning. On the one hand, the avCS+ was rated as more negative and more arousing than the CS- and induced startle potentiation and enhanced SCR. On the other hand, the appCS+ was rated more positive than the CS- and induced startle attenuation and larger SCR. In summary, we successfully confirmed animal findings in (hungry humans by demonstrating appetitive learning and normal aversive learning

  9. Parametric and genetic analysis of Drosophila appetitive long-term memory and sugar motivation.

    Science.gov (United States)

    Colomb, J; Kaiser, L; Chabaud, M-A; Preat, T

    2009-06-01

    Distinct forms of memory can be highlighted using different training protocols. In Drosophila olfactory aversive learning, one conditioning session triggers memory formation independently of protein synthesis, while five spaced conditioning sessions lead to the formation of long-term memory (LTM), a long-lasting memory dependent on de novo protein synthesis. In contrast, one session of odour-sugar association appeared sufficient for the fly to form LTM. We designed and tuned an apparatus that facilitates repeated discriminative conditioning by alternate presentations of two odours, one being associated with sugar, as well as a new paradigm to test sugar responsiveness (SR). Our results show that both SR and short-term memory (STM) scores increase with starvation length before conditioning. The protein dependency of appetitive LTM is independent of the repetition and the spacing of training sessions, on the starvation duration and on the strength of the unconditioned stimulus. In contrast to a recent report, our test measures an abnormal SR of radish mutant flies, which might initiate their STM and LTM phenotypes. In addition, our work shows that crammer and tequila mutants, which are deficient for aversive LTM, present both an SR and an appetitive STM defect. Using the MB247-P[switch] system, we further show that tequila is required in the adult mushroom bodies for normal sugar motivation.

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

    Science.gov (United States)

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

    2004-01-01

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

  11. [Drug control of appetite].

    Science.gov (United States)

    Makoundou, V; Golay, A

    2011-01-12

    The control of the appetite by drugs (sensation of hunger, satiation and satiety) is crucial in the management of obesity. Numerous drugs in this domain were forbidden these last years because of serious side effects. New researches allow the development of new substances presenting fewer side effects either by better specificity on receptors (locarserin), or by new mechanism of action (GLP-1, leptin, anti Ghrelin). The appetite is settled by a complex neurohormonal mechanism. To act on some systems at the same time, the development of products "polypill" combining naltroxone-bupropion, phentermine-topiramate or amylin-leptine give encouraging results. However the dominant mechanism of the appetite dysregulation needs to be better understood.

  12. Environmental enrichment has antidepressant-like action without improving learning and memory deficits in olfactory bulbectomized rats

    NARCIS (Netherlands)

    Hendriksen, H.; Meulendijks, D.; Douma, T.N.; Bink, D.I.; Breuer, M.E.; Westphal, K.G.; Olivier, B.; Oosting, R.S.

    2012-01-01

    Depression, especially in the elderly, is associated with poor cognitive functioning. Exercise has received much attention in the treatment for depression and also dementia. Here we studied the effect of an enriched environment combined with voluntary exercise (EE/VE) on the olfactory bulbectomized

  13. Olfactory system oscillations across phyla.

    Science.gov (United States)

    Kay, Leslie M

    2015-04-01

    Neural oscillations are ubiquitous in olfactory systems of mammals, insects and molluscs. Neurophysiological and computational investigations point to common mechanisms for gamma or odor associated oscillations across phyla (40-100Hz in mammals, 20-30Hz in insects, 0.5-1.5Hz in molluscs), engaging the reciprocal dendrodendritic synapse between excitatory principle neurons and inhibitory interneurons in the olfactory bulb (OB), antennal lobe (AL), or procerebrum (PrC). Recent studies suggest important mechanisms that may modulate gamma oscillations, including neuromodulators and centrifugal input to the OB and AL. Beta (20Hz) and theta (2-12Hz) oscillations coordinate activity within and across brain regions. Olfactory beta oscillations are associated with odor learning and depend on centrifugal OB input, while theta oscillations are strongly associated with respiration.

  14. Olfactory perception, communication, and the nose-to-brain pathway.

    Science.gov (United States)

    Stockhorst, Ursula; Pietrowsky, Reinhard

    2004-10-30

    The present paper's aim is of to give an overview about the basic knowledge as well as actual topics of olfaction--with a special regard on behavior. We summarize different functions of the nose and the olfactory system in human physiology and psychology. We will first describe the functional anatomy of the olfactory system in man. Afterwards, the function of the olfactory system will be viewed from an evolutionary and phylogenetic perspective. We will further outline the main features of olfactory perception, and will show how olfactory perception is influenced by learning. Olfactory signals are relevant stimuli that affect communication. Consequently, the role of the olfactory system in social interaction and mood will be described and gender differences will be addressed. Finally, the function of the nose as an interface to the brain, including implications for pharmacology, will be discussed.

  15. Olfactory Neuroblastoma: Diagnostic Difficulty

    Directory of Open Access Journals (Sweden)

    Vidya MN,

    2011-01-01

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

  16. Olfactory ensheathing cell tumor

    Directory of Open Access Journals (Sweden)

    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.

  17. On histamine and appetites

    Directory of Open Access Journals (Sweden)

    Fernando eTorrealba

    2012-07-01

    Full Text Available Brain histamine may influence a variety of different behavioral and physiological functions, but its responsibility in waking up has casted a long shadow on other important functions of this neurotransmitter. Here we review evidence indicating a central role of brain histamine in motivation, emphasizing its differential involvement in the appetitive and consummatory phases of motivated behaviors. We discuss the inputs that control the histaminergic neurons of the tuberomamillary nucleus of the hypothalamus, which determine the distinct role of these neurons in appetitive behavior, sleep/wake cycles and in food anticipatory activity. We review evidence supporting a dysfunction of histamine neurons and its cortical input in certain forms of decreased motivation (apathy. We finally discuss the relationship between the histamine system and drug addiction as a dysfunction of motivation.

  18. Probiotics and Appetite Regulation

    DEFF Research Database (Denmark)

    Bjerg, Anne Toksvig

    resistance and blood lipid profile among others. Probiotics which are health promoting bacteria can potentially be used to affect the GM and thereby change metabolic outcomes of the host. Animal studies have shown associations between intake of probiotics and appetite regulation, but currently no human...... studies have investigated this effect. Supplementation with different probiotic strains have been shown to have an effect on blood lipid profiles in both animals and humans and the mechanisms behind have been studied in vitro and in rodents. The aim of the present thesis was to examine in an ex vivo...... intestine, in an animal study and in two human studies the effect of the probiotic bacteria Lactobacillus paracasei subsp. paracasei L. casei W8 (W8) on appetite regulation, blood lipids and blood fatty acids. In addition, it was investigated if W8 had an effect on the fecal microbiota of the human...

  19. Probiotics and Appetite Regulation

    DEFF Research Database (Denmark)

    Bjerg, Anne Toksvig

    -armed parallel four weeks intervention study with W8 (1010 CFU) or placebo capsules was performed on young, normal to overweight participants. In the four weeks intervention study the effects of W8 on appetite, blood lipids, SCD1 activity and fecal microbiota were also investigated. Finally, associations between......Summary There is emerging focus on the gut microbiota’s (GM) effects on health. GM is suggested to be a contributing factor to the rapid development of obesity and its related diseases like type 2 diabetes and cardiovascular disease. The omposition of the GM has been associated with weight, insulin...... intestine, in an animal study and in two human studies the effect of the probiotic bacteria Lactobacillus paracasei subsp. paracasei L. casei W8 (W8) on appetite regulation, blood lipids and blood fatty acids. In addition, it was investigated if W8 had an effect on the fecal microbiota of the human...

  20. Hormonal Regulators of Appetite

    OpenAIRE

    Austin Juliana; Marks Daniel

    2008-01-01

    Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger a...

  1. Olfactory system and demyelination.

    Science.gov (United States)

    Garcia-Gonzalez, D; Murcia-Belmonte, V; Clemente, D; De Castro, F

    2013-09-01

    Within the central nervous system, the olfactory system represents one of the most exciting scenarios since it presents relevant examples of long-life sustained neurogenesis and continuous axonal outgrowth from the olfactory epithelium with the subsequent plasticity phenomena in the olfactory bulb. The olfactory nerve is composed of nonmyelinated axons with interesting ontogenetic interpretations. However, the centripetal projections from the olfactory bulb are myelinated axons which project to more caudal areas along the lateral olfactory tract. In consequence, demyelination has not been considered as a possible cause of the olfactory symptoms in those diseases in which this sense is impaired. One prototypical example of an olfactory disease is Kallmann syndrome, in which different mutations give rise to combined anosmia and hypogonadotropic hypogonadism, together with different satellite symptoms. Anosmin-1 is the extracellular matrix glycoprotein altered in the X-linked form of this disease, which participates in cell adhesion and migration, and axonal outgrowth in the olfactory system and in other regions of the central nervous system. Recently, we have described a new patho-physiological role of this protein in the absence of spontaneous remyelination in multiple sclerosis. In the present review, we hypothesize about how both main and satellite neurological symptoms of Kallmann syndrome may be explained by alterations in the myelination. We revisit the relationship between the olfactory system and myelin highlighting that minor histological changes should not be forgotten as putative causes of olfactory malfunction.

  2. Rules and mechanisms of punishment learning in honey bees: the aversive conditioning of the sting extension response.

    Science.gov (United States)

    Tedjakumala, Stevanus Rio; Giurfa, Martin

    2013-08-15

    Honeybees constitute established model organisms for the study of appetitive learning and memory. In recent years, the establishment of the technique of olfactory conditioning of the sting extension response (SER) has yielded new insights into the rules and mechanisms of aversive learning in insects. In olfactory SER conditioning, a harnessed bee learns to associate an olfactory stimulus as the conditioned stimulus with the noxious stimulation of an electric shock as the unconditioned stimulus. Here, we review the multiple aspects of honeybee aversive learning that have been uncovered using Pavlovian conditioning of the SER. From its behavioral principles and sensory variants to its cellular bases and implications for understanding social organization, we present the latest advancements in the study of punishment learning in bees and discuss its perspectives in order to define future research avenues and necessary improvements. The studies presented here underline the importance of studying honeybee learning not only from an appetitive but also from an aversive perspective, in order to uncover behavioral and cellular mechanisms of individual and social plasticity.

  3. Appetite and energy balancing.

    Science.gov (United States)

    Rogers, Peter J; Brunstrom, Jeffrey M

    2016-10-01

    The idea that food intake is motivated by (or in anticipation of) 'hunger' arising from energy depletion is apparent in both public and scientific discourse on eating behaviour. In contrast, our thesis is that eating is largely unrelated to short-term energy depletion. Energy requirements meal-to-meal are trivial compared with total body energy stores, and energy supply to the body's tissues is maintained if a meal or even several meals are missed. Complex and exquisite metabolic machinery ensures that this happens, but metabolic regulation is only loosely coupled with the control of energy intake. Instead, food intake needs to be controlled because the limited capacity of the gut means that processing a meal presents a significant physiological challenge and potentially hinders other activities. We illustrate the relationship between energy (food) intake and energy expenditure with a simple analogy in which: (1) water in a bathtub represents body energy content, (2) water in a saucepan represents food in the gut, and (3) the bathtub is filled via the saucepan. Furthermore, (4) it takes hours to process and pass the full energy (macronutrient) content of the saucepan to the bathtub, and (5) both the saucepan and bathtub resist filling, representing negative feedbacks on appetite (desire to eat). This model is consistent with the observations that appetite is reduced acutely by energy intake (a meal added to the limited capacity of the saucepan/gut), but not increased by an acute increase in energy expenditure (energy removed from the large store of energy in the bathtub/body). The existence of relatively very weak but chronic negative feedback on appetite proportional to body fatness is supported by observations on the dynamics of energy intake and weight gain in rat dietary obesity. (We use the term 'appetite' here because 'hunger' implies energy depletion.) In our model, appetite is motivated by the accessibility of food and the anticipated and experienced

  4. Is My Child's Appetite Normal?

    Science.gov (United States)

    ... child’s appetite changes. Children do not grow as fast in their preschool years. That is why your child may have a smaller appetite now. That is normal. If he or she is not hungry or does not finish a meal, relax. Take the food away. Your child probably is eating enough if ...

  5. Neuropharmacology of Human Appetite Expression

    Science.gov (United States)

    Halford, Jason C. G.; Harrold, Joanne A.

    2008-01-01

    The regulation of appetite relies on the integration of numerous episodic (meal) and tonic (energy storage) generated signals in energy regulatory centres within the central nervous system (CNS). These centers provide the pharmacological potential to modify human appetite (hunger and satiety) to increase or decrease caloric intake, or to normalize…

  6. 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.

  7. The strength of aversive and appetitive associations and maladaptive behaviors.

    Science.gov (United States)

    Itzhak, Yossef; Perez-Lanza, Daniel; Liddie, Shervin

    2014-08-01

    Certain maladaptive behaviors are thought to be acquired through classical Pavlovian conditioning. Exaggerated fear response, which can develop through Pavlovian conditioning, is associated with acquired anxiety disorders such as post-traumatic stress disorders (PTSDs). Inflated reward-seeking behavior, which develops through Pavlovian conditioning, underlies some types of addictive behavior (e.g., addiction to drugs, food, and gambling). These maladaptive behaviors are dependent on associative learning and the development of long-term memory (LTM). In animal models, an aversive reinforcer (fear conditioning) encodes an aversive contextual and cued LTM. On the other hand, an appetitive reinforcer results in conditioned place preference (CPP) that encodes an appetitive contextual LTM. The literature on weak and strong associative learning pertaining to the development of aversive and appetitive LTM is relatively scarce; thus, this review is particularly focused on the strength of associative learning. The strength of associative learning is dependent on the valence of the reinforcer and the salience of the conditioned stimulus that ultimately sways the strength of the memory trace. Our studies suggest that labile (weak) aversive and appetitive LTM may share similar signaling pathways, whereas stable (strong) aversive and appetitive LTM is mediated through different pathways. In addition, we provide some evidence suggesting that extinction of aversive fear memory and appetitive drug memory is likely to be mediated through different signaling molecules. We put forward the importance of studies aimed to investigate the molecular mechanisms underlying the development of weak and strong memories (aversive and appetitive), which would ultimately help in the development of targeted pharmacotherapies for the management of maladaptive behaviors that arise from classical Pavlovian conditioning.

  8. Hormonal Regulators of Appetite

    Directory of Open Access Journals (Sweden)

    Juliana Austin

    2009-01-01

    Full Text Available Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger and satiety. Mutations in these hormones or their receptors can cause substantial pathology leading to obesity or anorexia. Identification of individuals with specific genetic mutations may ultimately lead to more appropriate therapies targeted at the underlying disease process. Thus far, these hormones have mainly been studied in adults and animal models. This article is aimed at reviewing the hormones involved in hunger and satiety, with a focus on pediatrics.

  9. Hormonal Regulators of Appetite

    Directory of Open Access Journals (Sweden)

    Austin Juliana

    2008-11-01

    Full Text Available Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger and satiety. Mutations in these hormones or their receptors can cause substantial pathology leading to obesity or anorexia. Identification of individuals with specific genetic mutations may ultimately lead to more appropriate therapies targeted at the underlying disease process. Thus far, these hormones have mainly been studied in adults and animal models. This article is aimed at reviewing the hormones involved in hunger and satiety, with a focus on pediatrics.

  10. Meat and Appetite Regulation

    DEFF Research Database (Denmark)

    Kehlet, Ursula Nana

    D thesis was to investigate the effects of fiber addition to meatballs and the effects of cooking methods of pork on appetite regulation. The PhD thesis is based on three human meal test studies and one analytical study related to the characteristics of fiber meat products. In paper I, the objective...... pork products are also characterized as high fat products containing more than 10 g fat per 100 g. In this context, the Danish meat industry puts a lot of effort into developing meat products with a healthier nutritional profile. Thus, it is relevant to provide scientific evidence of the satiating...... effects of new formulations of pork products. Different strategies can be applied to potentially enhance the satiating properties of pork. Processed meat products such as meatballs can serve as a matrix for the addition of fiber ingredients. Based on their high protein and fiber contents, high...

  11. In vitro neuropeptide Y mRNA expressing model for screening essences that may affect appetite using Rolf B1.T cells.

    Science.gov (United States)

    Chen, Shiau-Wei; Wu, Po-Ju; Chiang, Been-Huang

    2012-08-15

    Neuropeptide Y (NPY) is the most important appetite regulator. This study aimed to establish an in vitro NPY mRNA expression model for screening essences to determine if they are an appetite stimulator or inhibitor. We cultured the olfactory nerve cells Rolf B1.T for 2 days and then treated the cells with the known appetite inhibitor limonene and stimulator linalool. It was found that linalool could significantly stimulate NPY mRNA expression in 10 min, and limonene had the opposite effect. Similar results were also found in primary olfactory ensheathing cells isolated from rats. Further clinical trials using human subjects found that, when 10 min of treatment was applied, linalool indeed increased the serum NPY level in human peripheral blood. Limonene, on the other hand, decreased the serum NPY level. Thus, NPY mRNA expression in Rolf B1.T cells could be used as an in vitro model for screening essences that may affect appetite.

  12. Functional Neuroanatomy of "Drosophila" Olfactory Memory Formation

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L.

    2014-01-01

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

  13. Olfactory Reference Syndrome

    Directory of Open Access Journals (Sweden)

    Alper Evrensel

    2015-12-01

    Full Text Available Olfactory reference syndrome is a delusional disorder in which the patient persistently and falsely believes that his or her body emits a foul odor. The disease is considered a variant of somatic type of delusional disorder under the diagnostic systems. Similarities between olfactory reference syndrome and obsessive compulsive disorder have also been noted. The etiopathogenesis of the disorder has not yet been clarified. Antidepressants, antipsychotics and psychotherapy are used in the treatment of this disorder. The aim of this article was to review clinical features, neurobiology, differantial diagnosis, classification problems and treatment of olfactory reference syndrome.

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

    OpenAIRE

    Kensaku eMori; Hiroyuki eManabe; Kimiya eNarikiyo; Naomi eOnisawa

    2013-01-01

    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 senso...

  15. Perceptual and neural olfactory similarity in honeybees.

    Directory of Open Access Journals (Sweden)

    Fernando Guerrieri

    2005-04-01

    Full Text Available The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones and in their carbon-chain length (from six to nine carbons. The results obtained by presentation of a total of 16 x 16 odour pairs show that (i all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii for some odour pairs, cross-generalisation between odorants was asymmetric; (iv a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours.

  16. Perceptual and Neural Olfactory Similarity in Honeybees

    Directory of Open Access Journals (Sweden)

    Guerrieri Fernando

    2005-01-01

    Full Text Available The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones and in their carbon-chain length (from six to nine carbons.The results obtained by presentation of a total of 16 x 16 odour pairs show that (i all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii for some odour pairs, cross-generalisation between odorants was asymmetric; (iv a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours.

  17. Forty years of olfactory navigation in birds.

    Science.gov (United States)

    Gagliardo, Anna

    2013-06-15

    Forty years ago, Papi and colleagues discovered that anosmic pigeons cannot find their way home when released at unfamiliar locations. They explained this phenomenon by developing the olfactory navigation hypothesis: pigeons at the home loft learn the odours carried by the winds in association with wind direction; once at the release site, they determine the direction of displacement on the basis of the odours perceived locally and orient homeward. In addition to the old classical experiments, new GPS tracking data and observations on the activation of the olfactory system in displaced pigeons have provided further evidence for the specific role of olfactory cues in pigeon navigation. Although it is not known which odours the birds might rely on for navigation, it has been shown that volatile organic compounds in the atmosphere are distributed as fairly stable gradients to allow environmental odour-based navigation. The investigation of the potential role of olfactory cues for navigation in wild birds is still at an early stage; however, the evidence collected so far suggests that olfactory navigation might be a widespread mechanism in avian species.

  18. Linking adult olfactory neurogenesis to social behavior

    Directory of Open Access Journals (Sweden)

    Claudia E Feierstein

    2012-11-01

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

  19. Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants

    OpenAIRE

    Guerrieri, Fernando Javier; D'Ettorre, Patrizia; Deveaud, J-M.; Giurfa, M.

    2011-01-01

    Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and nonrewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein sy...

  20. Ionotropic crustacean olfactory receptors.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Corey

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

  1. Construction of odor representations by olfactory bulb microcircuits.

    Science.gov (United States)

    Cleland, Thomas A

    2014-01-01

    Like other sensory systems, the olfactory system transduces specific features of the external environment and must construct an organized sensory representation from these highly fragmented inputs. As with these other systems, this representation is not accurate per se, but is constructed for utility, and emphasizes certain, presumably useful, features over others. I here describe the cellular and circuit mechanisms of the peripheral olfactory system that underlie this process of sensory construction, emphasizing the distinct architectures and properties of the two prominent computational layers in the olfactory bulb. Notably, while the olfactory system solves essentially similar conceptual problems to other sensory systems, such as contrast enhancement, activity normalization, and extending dynamic range, its peculiarities often require qualitatively different computational algorithms than are deployed in other sensory modalities. In particular, the olfactory modality is intrinsically high dimensional, and lacks a simple, externally defined basis analogous to wavelength or pitch on which elemental odor stimuli can be quantitatively compared. Accordingly, the quantitative similarities of the receptive fields of different odorant receptors (ORs) vary according to the statistics of the odor environment. To resolve these unusual challenges, the olfactory bulb appears to utilize unique nontopographical computations and intrinsic learning mechanisms to perform the necessary high-dimensional, similarity-dependent computations. In sum, the early olfactory system implements a coordinated set of early sensory transformations directly analogous to those in other sensory systems, but accomplishes these with unique circuit architectures adapted to the properties of the olfactory modality.

  2. Inducible activation of ERK5 MAP kinase enhances adult neurogenesis in the olfactory bulb and improves olfactory function.

    Science.gov (United States)

    Wang, Wenbin; Lu, Song; Li, Tan; Pan, Yung-Wei; Zou, Junhui; Abel, Glen M; Xu, Lihong; Storm, Daniel R; Xia, Zhengui

    2015-05-20

    Recent discoveries have suggested that adult neurogenesis in the subventricular zone (SVZ) and olfactory bulb (OB) may be required for at least some forms of olfactory behavior in mice. However, it is unclear whether conditional and selective enhancement of adult neurogenesis by genetic approaches is sufficient to improve olfactory function under physiological conditions or after injury. Furthermore, specific signaling mechanisms regulating adult neurogenesis in the SVZ/OB are not fully defined. We previously reported that ERK5, a MAP kinase selectively expressed in the neurogenic regions of the adult brain, plays a critical role in adult neurogenesis in the SVZ/OB. Using a site-specific knock-in mouse model, we report here that inducible and targeted activation of the endogenous ERK5 in adult neural stem/progenitor cells enhances adult neurogenesis in the OB by increasing cell survival and neuronal differentiation. This conditional ERK5 activation also improves short-term olfactory memory and odor-cued associative olfactory learning under normal physiological conditions. Furthermore, these mice show enhanced recovery of olfactory function and have more adult-born neurons after a zinc sulfate-induced lesion of the main olfactory epithelium. We conclude that ERK5 MAP kinase is an important endogenous signaling pathway regulating adult neurogenesis in the SVZ/OB, and that conditional activation of endogenous ERK5 is sufficient to enhance adult neurogenesis in the OB thereby improving olfactory function both under normal conditions and after injury.

  3. 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)

    Maïna eBRUS

    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.

  4. A physiological increase of insulin in the olfactory bulb decreases detection of a learned aversive odor and abolishes food odor-induced sniffing behavior in rats.

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    Pascaline Aimé

    Full Text Available Insulin is involved in multiple regulatory mechanisms, including body weight and food intake, and plays a critical role in metabolic disorders such as obesity and diabetes. An increasing body of evidence indicates that insulin is also involved in the modulation of olfactory function. The olfactory bulb (OB contains the highest level of insulin and insulin receptors (IRs in the brain. However, a role for insulin in odor detection and sniffing behavior remains to be elucidated. Using a behavioral paradigm based on conditioned olfactory aversion (COA to isoamyl-acetate odor, we demonstrated that an intracerebroventricular (ICV injection of 14 mU insulin acutely decreased olfactory detection of fasted rats to the level observed in satiated animals. In addition, whereas fasted animals demonstrated an increase in respiratory frequency upon food odor detection, this effect was absent in fasted animals receiving a 14 mU insulin ICV injection as well as in satiated animals. In parallel, we showed that the OB and plasma insulin levels were increased in satiated rats compared to fasted rats, and that a 14 mU insulin ICV injection elevated the OB insulin level of fasted rats to that of satiated rats. We further quantified insulin receptors (IRs distribution and showed that IRs are preferentially expressed in the caudal and lateral parts of the main OB, with the highest labeling found in the mitral cells, the main OB projection neurons. Together, these data suggest that insulin acts on the OB network to modulate olfactory processing and demonstrate that olfactory function is under the control of signals involved in energy homeostasis regulation and feeding behaviors.

  5. A Physiological Increase of Insulin in the Olfactory Bulb Decreases Detection of a Learned Aversive Odor and Abolishes Food Odor-Induced Sniffing Behavior in Rats

    Science.gov (United States)

    Aimé, Pascaline; Hegoburu, Chloé; Jaillard, Tristan; Degletagne, Cyril; Garcia, Samuel; Messaoudi, Belkacem; Thevenet, Marc; Lorsignol, Anne; Duchamp, Claude; Mouly, Anne-Marie; Julliard, Andrée Karyn

    2012-01-01

    Insulin is involved in multiple regulatory mechanisms, including body weight and food intake, and plays a critical role in metabolic disorders such as obesity and diabetes. An increasing body of evidence indicates that insulin is also involved in the modulation of olfactory function. The olfactory bulb (OB) contains the highest level of insulin and insulin receptors (IRs) in the brain. However, a role for insulin in odor detection and sniffing behavior remains to be elucidated. Using a behavioral paradigm based on conditioned olfactory aversion (COA) to isoamyl-acetate odor, we demonstrated that an intracerebroventricular (ICV) injection of 14 mU insulin acutely decreased olfactory detection of fasted rats to the level observed in satiated animals. In addition, whereas fasted animals demonstrated an increase in respiratory frequency upon food odor detection, this effect was absent in fasted animals receiving a 14 mU insulin ICV injection as well as in satiated animals. In parallel, we showed that the OB and plasma insulin levels were increased in satiated rats compared to fasted rats, and that a 14 mU insulin ICV injection elevated the OB insulin level of fasted rats to that of satiated rats. We further quantified insulin receptors (IRs) distribution and showed that IRs are preferentially expressed in the caudal and lateral parts of the main OB, with the highest labeling found in the mitral cells, the main OB projection neurons. Together, these data suggest that insulin acts on the OB network to modulate olfactory processing and demonstrate that olfactory function is under the control of signals involved in energy homeostasis regulation and feeding behaviors. PMID:23251461

  6. An Appetite for Fractions

    Science.gov (United States)

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  7. 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 hunger (p satiety (p hunger state.

  8. Respective Role of the Dorsal Hippocampus and the Entorhinal Cortex during the Recombination of Previously Learned Olfactory-Tactile Associations in the Rat

    Science.gov (United States)

    Boisselier, Lise; Ferry, Barbara; Gervais, Rémi

    2017-01-01

    The hippocampal formation has been extensively described as a key component for object recognition in conjunction with place and context. The present study aimed at describing neural mechanisms in the hippocampal formation that support olfactory-tactile (OT) object discrimination in a task where space and context were not taken into account. The…

  9. Experiential effects of appetitive and nonappetitive odors on feeding behavior in the blowfly, Phormia regina: a putative role for tyramine in appetite regulation.

    Science.gov (United States)

    Nisimura, Tomoyosi; Seto, Atsushi; Nakamura, Kyoko; Miyama, Mayumi; Nagao, Takashi; Tamotsu, Satoshi; Yamaoka, Ryohei; Ozaki, Mamiko

    2005-08-17

    In humans, appetite is affected by food experiences and food flavors. In the blowfly Phormia regina, we found that feeding threshold to sugar increased in the presence of the odor of D-limonene and decreased in the presence of the odor of dithiothreitol (DTT). Using these odors as representative nonappetitive and appetitive flavors, we demonstrated the role played by tyramine (TA) in appetite regulation by experiences of food flavors. When fed with sucrose flavored with D-limonene for 5 d after emergence, flies showed subsequent decreased appetite to plain sucrose, whereas when they were fed with sucrose flavored by DTT they showed increased appetite. However, mushroom body (MB)-ablated flies did not show these patterns. This suggests that MB, one of the primary memory centers of the insect brain, is necessary for the flies to apply previous experiences of food flavors to appetitive learning behaviors. In addition, flies' previously acquired decreased or increased appetites showed parallel changes with both octopamine (OA) and tyramine levels in the brain. However, injection experiments with OA, TA, or their agonist and antagonist indicated that TA more directly mediates feeding threshold determination, which was affected by acquired memories of food flavors.

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

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    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.

  11. PERIPHERAL MECHANISMS IN APPETITE REGULATION

    Science.gov (United States)

    Camilleri, Michael

    2014-01-01

    Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide input to the highly organized hypothalamic circuitry and vagal complex of nuclei to determine cessation of energy intake during meal ingestion, and the return of appetite and hunger after fasting. Understanding these mechanisms is key to the physiological control of feeding and the derangements that occur in obesity and their restoration with treatment (as demonstrated by the effects of bariatric surgery). PMID:25241326

  12. Peripheral mechanisms in appetite regulation.

    Science.gov (United States)

    Camilleri, Michael

    2015-05-01

    Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide input to the highly organized hypothalamic circuitry and vagal complex of nuclei to determine cessation of energy intake during meal ingestion, and the return of appetite and hunger after fasting. Understanding these mechanisms is key to the physiological control of feeding and the derangements that occur in obesity and their restoration with treatment (as shown by the effects of bariatric surgery). Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

  13. PERIPHERAL MECHANISMS IN APPETITE REGULATION

    OpenAIRE

    Camilleri, Michael

    2014-01-01

    Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide inpu...

  14. 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...

  15. Clinical Approach to Children with Low Appetite

    OpenAIRE

    Fatih Ünal

    2011-01-01

    Appetite is a conscious desire for food and it is regulated mainly by the gastrointestinal system, pancreas and adrenal glands. Poor appetite is a common problem in childhood. For assessment, history of development, nutrition and family are important. Poor appetite may also be a symptom of feeding disorders. Even though the etiology of feeding disorders may be classified as organic or functional, it indeed reflects the complex interaction of biological, behavioral and social factors. Personal...

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

    Science.gov (United States)

    Mori, Kensaku; Manabe, Hiroyuki; Narikiyo, Kimiya; Onisawa, Naomi

    2013-01-01

    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 may require 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.

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

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    Kensaku eMori

    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. Development and Organization of the Evolutionarily Conserved Three-Layered Olfactory Cortex

    Science.gov (United States)

    2017-01-01

    Abstract The olfactory cortex is part of the mammalian cerebral cortex together with the neocortex and the hippocampus. It receives direct input from the olfactory bulbs and participates in odor discrimination, association, and learning (Bekkers and Suzuki, 2013). It is thought to be an evolutionarily conserved paleocortex, which shares common characteristics with the three-layered general cortex of reptiles (Aboitiz et al., 2002). The olfactory cortex has been studied as a “simple model” to address sensory processing, though little is known about its precise cell origin, diversity, and identity. While the development and the cellular diversity of the six-layered neocortex are increasingly understood, the olfactory cortex remains poorly documented in these aspects. Here is a review of current knowledge of the development and organization of the olfactory cortex, keeping the analogy with those of the neocortex. The comparison of olfactory cortex and neocortex will allow the opening of evolutionary perspectives on cortical development.

  19. Attention and Olfactory Consciousness

    Directory of Open Access Journals (Sweden)

    Andreas eKeller

    2011-12-01

    Full Text Available Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to the discussion: attention to the olfactory modality. I will first clarify the position of attention to smells in a general taxonomy of attention. I will then review the mechanisms and neuroanatomy of attention and consciousness in the olfactory system before using the newly introduced system to provide evidence that attention is necessary for consciousness.

  20. Beta and gamma oscillatory activities associated with olfactory memory tasks: Different rhythms for different functional networks?

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    Claire eMartin

    2014-06-01

    Full Text Available Olfactory processing in behaving animals, even at early stages, is inextricable from top down influences associated with odor perception. The anatomy of the olfactory network (olfactory bulb, piriform and entorhinal cortices and its unique direct access to the limbic system makes it particularly attractive to study how sensory processing could be modulated by learning and memory. Moreover, olfactory structures have been early reported to exhibit oscillatory population activities easy to capture through local field potential recordings. An attractive hypothesis is that neuronal oscillations would serve to ‘bind’ distant structures to reach a unified and coherent perception. In relation to this hypothesis, we will assess the functional relevance of different types of oscillatory activity observed in the olfactory system of behaving animals. This review will focus primarily on two types of oscillatory activities: beta (15-40 Hz and gamma (60-100 Hz. While gamma oscillations are dominant in the olfactory system in the absence of odorant, both beta and gamma rhythms have been reported to be modulated depending on the nature of the olfactory task. Studies from the authors of the present review and other groups brought evidence for a link between these oscillations and behavioral changes induced by olfactory learning. However, differences in studies led to divergent interpretations concerning the respective role of these oscillations in olfactory processing. Based on a critical reexamination of those data, we propose hypotheses on the functional involvement of beta and gamma oscillations for odor perception and memory.

  1. Olfactory toxicity in fishes.

    Science.gov (United States)

    Tierney, Keith B; Baldwin, David H; Hara, Toshiaki J; Ross, Peter S; Scholz, Nathaniel L; Kennedy, Christopher J

    2010-01-21

    Olfaction conveys critical environmental information to fishes, enabling activities such as mating, locating food, discriminating kin, avoiding predators and homing. All of these behaviors can be impaired or lost as a result of exposure to toxic contaminants in surface waters. Historically, teleost olfaction studies have focused on behavioral responses to anthropogenic contaminants (e.g., avoidance). More recently, there has been a shift towards understanding the underlying mechanisms and functional significance of contaminant-mediated changes in fish olfaction. This includes a consideration of how contaminants affect the olfactory nervous system and, by extension, the downstream physiological and behavioral processes that together comprise a normal response to naturally occurring stimuli (e.g., reproductive priming or releasing pheromones). Numerous studies spanning several species have shown that ecologically relevant exposures to common pollutants such as metals and pesticides can interfere with fish olfaction and disrupt life history processes that determine individual survival and reproductive success. This represents one of the pathways by which toxic chemicals in aquatic habitats may increasingly contribute to the decline and at-risk status of many commercially and ecologically important fish stocks. Despite our emerging understanding of the threats that pollution poses for chemical communication in aquatic communities, many research challenges remain. These include: (1) the determination of specific mechanisms of toxicity in the fish olfactory sensory epithelium; (2) an understanding of the impacts of complex chemical mixtures; (3) the capacity to assess olfactory toxicity in fish in situ; (4) the impacts of toxins on olfactory-mediated behaviors that are still poorly understood for many fish species; and (5) the connections between sublethal effects on individual fish and the long-term viability of wild populations. This review summarizes and integrates

  2. Olfactory Loss in Parkinson's Disease

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    Antje Haehner

    2011-01-01

    Full Text Available Impairment of olfaction is a characteristic and early feature of Parkinson's disease. Recent data indicate that >95% of patients with Parkinson's disease present with significant olfactory loss. Deficits in the sense of smell may precede clinical motor symptoms by years and can be used to assess the risk for developing Parkinson's disease in otherwise asymptomatic individuals. This paper summarizes the available information about olfactory function in Parkinson's disease, indicating the advantageous use of olfactory probes in early and differential diagnosis.

  3. Recent Trend in Development of Olfactory Displays

    Science.gov (United States)

    Yanagida, Yasuyuki

    An olfactory display is a device that generates scented air with desired concentration of aroma, and delivers it to the user's olfactory organ. In this article, the nature of olfaction is briefly described from the view point of how to configure olfactory displays. Next, component technologies to compose olfactory displays, i.e., making scents and delivering scents, are categorized. Several existing olfactory display systems are introduced to show the current status of research and development of olfactory displays.

  4. Classical olfactory conditioning in the oriental fruit fly, Bactrocera dorsalis.

    Science.gov (United States)

    Liu, Jia Li; Chen, Xiao Yan; Zeng, Xin Nian

    2015-01-01

    The oriental fruit fly, Bactrocera dorsalis, is a serious pest of fruits and vegetables. Methyl eugenol (ME), a male attractant, is used to against this fly by mass trapping. Control effect may be influenced by learning, which could modify the olfactory response of the fly to this attractant. To collect the behavioral evidence, studies on the capability of this fly for olfactory learning are necessary. We investigated olfactory learning in male flies with a classical olfactory conditioning procedure using restrained individuals under laboratory conditions. The acquisition of the proboscis extension reflex was used as the criterion for conditioning. A high conditioned response level was found in oriental fruit flies when an odor was presented in paired association with a sucrose reward but not when the odor and sucrose were presented unpaired. We also found that the conditioning performance was influenced by the odor concentration, intertrial interval, and starvation time. A slight sensitization elicited by imbibing sucrose was observed. These results indicate that oriental fruit flies have a high capacity to form an olfactory memory as a result of classical conditioning.

  5. The cyclic nucleotide gated channel subunit CNG-1 instructs behavioral outputs in Caenorhabditis elegans by coincidence detection of nutritional status and olfactory input.

    Science.gov (United States)

    He, Chao; Altshuler-Keylin, Svetlana; Daniel, David; L'Etoile, Noelle D; O'Halloran, Damien

    2016-10-06

    In mammals, olfactory subsystems have been shown to express seven-transmembrane G-protein-coupled receptors (GPCRs) in a one-receptor-one-neuron pattern, whereas in Caenorhabditis elegans, olfactory sensory neurons express multiple G-protein coupled odorant receptors per olfactory sensory neuron. In both mammalian and C. elegans olfactory sensory neurons (OSNs), the process of olfactory adaptation begins within the OSN; this process of negative feedback within the mammalian OSN has been well described in mammals and enables activated OSNs to desensitize their response cell autonomously while attending to odors detected by separate OSNs. However, the mechanism that enables C. elegans to adapt to one odor and attend to another odor sensed by the same olfactory sensory neuron remains unclear. We found that the cyclic nucleotide gated channel subunit CNG-1 is required to promote cross adaptation responses between distinct olfactory cues. This change in sensitivity to a pair of odorants after persistent stimulation by just one of these odors is modulated by the internal nutritional state of the animal, and we find that this response is maintained across a diverse range of food sources for C. elegans. We also reveal that CNG-1 integrates food related cues for exploratory motor output, revealing that CNG-1 functions in multiple capacities to link nutritional information with behavioral output. Our data describes a novel model whereby CNG channels can integrate the coincidence detection of appetitive and olfactory information to set olfactory preferences and instruct behavioral outputs.

  6. Modelling synergistic effects of appetite regulating hormones

    DEFF Research Database (Denmark)

    Schmidt, Julie Berg; Ritz, Christian

    2016-01-01

    We briefly reviewed one definition of dose addition, which is applicable within the framework of generalized linear models. We established how this definition of dose addition corresponds to effect addition in case only two doses per compound are considered for evaluating synergistic effects. The....... The link between definitions was exemplified for an appetite study where two appetite hormones were studied....

  7. Differential Endocannabinoid Regulation of Extinction in Appetitive and Aversive Barnes Maze Tasks

    Science.gov (United States)

    Harloe, John P.; Thorpe, Andrew J.; Lichtman, Aron H.

    2008-01-01

    CB[subscript 1] receptor-compromised animals show profound deficits in extinguishing learned behavior from aversive conditioning tasks, but display normal extinction learning in appetitive operant tasks. However, it is difficult to discern whether the differential involvement of the endogenous cannabinoid system on extinction results from the…

  8. Food Preference and Appetite after Switching between Sweet and Savoury Odours in Women.

    Directory of Open Access Journals (Sweden)

    Mariëlle G Ramaekers

    Full Text Available Exposure to food odours increases the appetite for congruent foods and decreases the appetite for incongruent foods. However, the effect of exposure to a variety of food odours, as often occurs in daily life, is unknown.Investigate how switching between sweet and savoury odours affects the appetite for sweet and savoury products.Thirty women (age: 18-45y; BMI: 18.5-25kg/m2 intensely smelled the contents of cups filled with banana, meat or water (no-odour in a within-subject design with four combinations: no-odour/banana, no-odour/meat, meat/banana and banana/meat. Participants received one combination per test day. In each combination, two cups with different fillings were smelled for five minutes after each other. Treatment order was balanced as much as possible. The effects of previous exposure and current odour on the appetite for (incongruent sweet and savoury products, and odour pleasantness were analysed. A change from meat to banana odour or banana to meat odour was referred to as switch, whereas a change from no-odour to meat odour or no-odour to banana odour was no-switch.The current odour (P<0.001, as opposed to the previous exposure (P = 0.71, determined the appetite for (incongruent sweet and savoury products, already one minute after a switch between sweet and savoury odours. The pleasantness of the odour decreased during odour exposure (P = 0.005.After a switch, the appetite for specific products quickly adjusted to the new odour and followed the typical pattern as found during odour exposure in previous studies. Interestingly, the appetite for the smelled food remained elevated during odour exposure, known as sensory-specific appetite, whereas the pleasantness of the odour decreased over time, previously termed olfactory sensory-specific satiety. This seeming contradiction may result from different mechanisms underlying the odour-induced anticipation of food intake versus the decrease in hedonic value during prolonged sensory

  9. Early olfactory environment influences social behaviour in adult Octodon degus.

    Directory of Open Access Journals (Sweden)

    Natalia Márquez

    Full Text Available We evaluated the extent to which manipulation of early olfactory environment can influence social behaviours in the South American Hystricognath rodent Octodon degus. The early olfactory environment of newborn degus was manipulated by scenting all litter members with eucalyptol during the first month of life. The social behaviour of sexually mature animals (5-7 months old towards conspecifics was then assessed using a y-maze to compare the response of control (naïve and treated animals to two different olfactory configurations (experiment 1: (i a non-familiarized conspecific impregnated with eucalyptol (eucalyptol arm presented against (ii a non-familiarized unscented conspecific (control arm. In addition, in dyadic encounters, we assessed the behaviour of control and eucalyptol treated animals towards a non-familiarized conspecific scented with eucalyptol (experiment 2. We found that control subjects explored and spent significantly less time in the eucalyptol arm, indicating neophobic behaviours towards the artificially scented conspecific. Treated subjects explored and spent similar time in both arms of the maze, showing the same interest for both olfactory stimuli presented. During dyadic encounters in experiment 2, an interaction effect between early experience and sex was observed. Control males escaped and avoided their scented partner more frequently than eucalyptol treated male subjects and than females. Both groups did not differ in the exploration of their scented partners, suggesting that avoidance within agonistic context does not relate to neophobic behaviours. Our results suggest that the exposure to eucalyptol during early ontogeny decreases evasive behaviours within an agonistic context as a result of olfactory learning. Altogether, these results indicate that olfactory cues learned in early ontogeny can influence olfactory-guided behaviours in adult degus.

  10. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

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

    2011-01-01

    Any living organism interacts with and responds specifically to environmental molecules by expressing specific olfactory receptors. This specificity will be first examined in causal terms with particular emphasis on the mechanisms controlling olfactory gene expression, cell-to-cell interactions a...

  11. The Effect of Wholegrain on Appetite

    DEFF Research Database (Denmark)

    Ibrügger, Sabine

    . In the long run, regular wholegrain intake may also reduce body weight due to reoccurring short- and long-term effects on appetite. Aim: This PhD thesis investigates the effects of selected wholegrain products on appetite after a second meal, as well as the effects of sustained wholegrain intake on overall...... appetite sensation with special attention to the role of colonic fermentation. Further, the impact of regular wholegrain intake on body weight is investigated. Methods: In a second meal study we studied the effects of two coarse wholegrain rye evening meals on subjective appetite after a standardized...... breakfast and on ad libitum energy intake at lunch at the subsequent day compared to white wheat bread. In a human intervention study we investigated the effects of 8-week ad libitum consumption of a mixed wholegrain diet on appetite after a standardized, non-wholegrain breakfast, on ad libitum energy...

  12. The Effect of Wholegrain on Appetite

    DEFF Research Database (Denmark)

    Ibrügger, Sabine

    . In the long run, regular wholegrain intake may also reduce body weight due to reoccurring short- and long-term effects on appetite. Aim: This PhD thesis investigates the effects of selected wholegrain products on appetite after a second meal, as well as the effects of sustained wholegrain intake on overall...... appetite sensation with special attention to the role of colonic fermentation. Further, the impact of regular wholegrain intake on body weight is investigated. Methods: In a second meal study we studied the effects of two coarse wholegrain rye evening meals on subjective appetite after a standardized...... breakfast and on ad libitum energy intake at lunch at the subsequent day compared to white wheat bread. In a human intervention study we investigated the effects of 8-week ad libitum consumption of a mixed wholegrain diet on appetite after a standardized, non-wholegrain breakfast, on ad libitum energy...

  13. Clinical Approach to Children with Low Appetite

    Directory of Open Access Journals (Sweden)

    Fatih Ünal

    2011-08-01

    Full Text Available Appetite is a conscious desire for food and it is regulated mainly by the gastrointestinal system, pancreas and adrenal glands. Poor appetite is a common problem in childhood. For assessment, history of development, nutrition and family are important. Poor appetite may also be a symptom of feeding disorders. Even though the etiology of feeding disorders may be classified as organic or functional, it indeed reflects the complex interaction of biological, behavioral and social factors. Personal, familial, economic and sociocultural factors may affect appetite. In this review, approaches to a child with low appetite who presents a difficult problem for his/her family and doctor are discussed in the light of recent literature. (Journal of Current Pediatrics 2011; 9: 79-84

  14. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

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

    2011-01-01

    Any living organism interacts with and responds specifically to environmental molecules by expressing specific olfactory receptors. This specificity will be first examined in causal terms with particular emphasis on the mechanisms controlling olfactory gene expression, cell-to-cell interactions...... and odor-decoding processes. However, this type of explanation does not entirely justify the role olfactory receptors have played during evolution, since they are also expressed ectopically in different organs and/or tissues. Homologous olfactory genes have in fact been found in such diverse cells and....../or organs as spermatozoa, testis and kidney where they are assumed to act as chemotactic sensors or renin modulators. To justify their functional diversity, homologous olfactory receptors are assumed to share the same basic role: that of conferring a self-identity to cells or tissues under varying...

  15. Descriptive epidemiology of selected olfactory tumors.

    Science.gov (United States)

    Villano, J Lee; Bressler, Linda; Propp, Jennifer M; Valyi-Nagy, Tibor; Martin, Iman K; Dolecek, Therese A; McCarthy, Bridget J

    2010-10-01

    Olfactory tumors, especially olfactory neuroblastomas (ON) and carcinomas with neuroendocrine differentiation (CND), are extremely rare, and little descriptive epidemiologic information is available. The objective of this study was to more fully describe selected olfactory tumors using a large population-based cancer incidence database. The Surveillance, Epidemiology and End Results (SEER) 9 registries limited-use data were reviewed from 1973 to 2006 for selected nasal cavity (C30.0) and accessory sinus (C31.0-31.9) tumors. Frequencies, incidence rates, and relative survival rates were estimated using SEER*Stat, v6.5.2. The majority of cases were squamous cell carcinoma (SCC), while the incidence of ON was greater than CND. For ON, the incidence was highest in the 60-79 year age group, while for SCC, the incidence was highest in the 80+ year age group. For CND, the incidence leveled off in the oldest age groups. Survival rates were highest for ON (>70% alive at 5 years after diagnosis) and poorest for CND (44% alive at 5 years). Adjuvant radiation therapy did not improve survival over surgery alone in ON. In SCC, survival was worse in patients who received adjuvant radiation compared to patients who had surgery alone. Our analysis confirms some previously published information, and adds new information about the incidence and demographics of ON and CND. In addition, our analysis documents the lack of benefit of adjuvant radiation in ON. It is not feasible to conduct prospective trials in patients with these rare diseases, and the importance of registry data in learning about olfactory tumors is emphasized.

  16. Food Preference and Appetite after Switching between Sweet and Savoury Odours in Women.

    Science.gov (United States)

    Ramaekers, Mariëlle G; Luning, Pieternel A; Lakemond, Catriona M M; van Boekel, Martinus A J S; Gort, Gerrit; Boesveldt, Sanne

    2016-01-01

    Exposure to food odours increases the appetite for congruent foods and decreases the appetite for incongruent foods. However, the effect of exposure to a variety of food odours, as often occurs in daily life, is unknown. Investigate how switching between sweet and savoury odours affects the appetite for sweet and savoury products. Thirty women (age: 18-45y; BMI: 18.5-25kg/m2) intensely smelled the contents of cups filled with banana, meat or water (no-odour) in a within-subject design with four combinations: no-odour/banana, no-odour/meat, meat/banana and banana/meat. Participants received one combination per test day. In each combination, two cups with different fillings were smelled for five minutes after each other. Treatment order was balanced as much as possible. The effects of previous exposure and current odour on the appetite for (in)congruent sweet and savoury products, and odour pleasantness were analysed. A change from meat to banana odour or banana to meat odour was referred to as switch, whereas a change from no-odour to meat odour or no-odour to banana odour was no-switch. The current odour (Pfood remained elevated during odour exposure, known as sensory-specific appetite, whereas the pleasantness of the odour decreased over time, previously termed olfactory sensory-specific satiety. This seeming contradiction may result from different mechanisms underlying the odour-induced anticipation of food intake versus the decrease in hedonic value during prolonged sensory stimulation.

  17. Fish as aquatic “sniffer dogs”: Olfactory-mediated behaviors and conditioning of common carps to cadaver odors

    Directory of Open Access Journals (Sweden)

    Brian Wade Jamandre

    2015-12-01

    Full Text Available Even with the aide of modern technology, the search for cadaver or human remains underwater is still assisted by sniffer dogs mainly because of their superior sense of olfaction. However, dogs rely on volatile organic compounds in the air and that this may constraint their ability when searching for submerged cadavers. On the other hand, it has long been recognized that fishes use olfaction to sample odors from their surroundings to accomplish a task and are capable of acquiring new skills through training or conditioning. Despite decades of experimental and observational studies of the olfactory sensitivities of fishes, its potential application to forensic sciences has never been truly explored. In this pioneering research, we explore the possibility of using fish olfaction in detecting cadaver odors (porcine origin, using common carps Cyprinus carpio as model species in a series of experiments under laboratory conditions. We first observed the innate behavior of carps towards cadaver odors. Afterwards, the carps were trained in two-choice chamber experimental tanks by appetitive olfactory conditioning and odor masking methods. We also experimented on the effects of cadaver odors by early exposure using eggs and larval impregnation techniques, and observing the behaviors when they develop to early juveniles. In general, we found out that common carps are naturally repelled to cadaver odors. However using our devised conditioning protocol, results show that the conditioned carps were able to learn to be attracted to cadaver odors despite their innate aversion. The development of fish for cadaver detection is a simple but innovative idea and that it may present a cost-effective and reliable solution for the shortcomings of the existing methods in underwater cadaver search. We anticipate that this research will open up a variety of different studies in pursuit of developing fishes as biosensors and its application to forensic sciences.

  18. Molecular Mechanisms of Appetite Regulation

    Directory of Open Access Journals (Sweden)

    Ji Hee Yu

    2012-12-01

    Full Text Available The prevalence of obesity has been rapidly increasing worldwide over the last several decades and has become a major health problem in developed countries. The brain, especially the hypothalamus, plays a key role in the control of food intake by sensing metabolic signals from peripheral organs and modulating feeding behaviors. To accomplish these important roles, the hypothalamus communicates with other brain areas such as the brainstem and reward-related limbic pathways. The adipocyte-derived hormone leptin and pancreatic β-cell-derived insulin inform adiposity to the hypothalamus. Gut hormones such as cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1, and oxyntomodulin transfer satiety signals to the brain and ghrelin relays hunger signals. The endocannabinoid system and nutrients are also involved in the physiological regulation of food intake. In this article, we briefly review physiological mechanisms of appetite regulation.

  19. Molecular mechanisms of appetite regulation.

    Science.gov (United States)

    Yu, Ji Hee; Kim, Min-Seon

    2012-12-01

    The prevalence of obesity has been rapidly increasing worldwide over the last several decades and has become a major health problem in developed countries. The brain, especially the hypothalamus, plays a key role in the control of food intake by sensing metabolic signals from peripheral organs and modulating feeding behaviors. To accomplish these important roles, the hypothalamus communicates with other brain areas such as the brainstem and reward-related limbic pathways. The adipocyte-derived hormone leptin and pancreatic β-cell-derived insulin inform adiposity to the hypothalamus. Gut hormones such as cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1, and oxyntomodulin transfer satiety signals to the brain and ghrelin relays hunger signals. The endocannabinoid system and nutrients are also involved in the physiological regulation of food intake. In this article, we briefly review physiological mechanisms of appetite regulation.

  20. 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.

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

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    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.

  2. Appetitive behaviours of children attending obesity treatment.

    Science.gov (United States)

    Croker, H; Cooke, L; Wardle, J

    2011-10-01

    Associations between appetite and adiposity have not been examined in clinical samples of obese children. The Children's Eating Behaviour Questionnaire (CEBQ) was used to compare appetite in community (n=406) and clinical (n=66) samples. Clear graded patterns were seen for food responsiveness and emotional overeating; levels increased with increasing BMI SDS and the clinical sample scored highest. The reverse was seen for satiety responsiveness/slowness in eating. Differences were not solely explained by weight differences, suggesting that the clinical sample had more pronounced 'obesogenic' appetitive traits. This could make adherence to dietary guidance difficult.

  3. A neural network model for olfactory glomerular activity prediction

    Science.gov (United States)

    Soh, Zu; Tsuji, Toshio; Takiguchi, Noboru; Ohtake, Hisao

    2012-12-01

    Recently, the importance of odors and methods for their evaluation have seen increased emphasis, especially in the fragrance and food industries. Although odors can be characterized by their odorant components, their chemical information cannot be directly related to the flavors we perceive. Biological research has revealed that neuronal activity related to glomeruli (which form part of the olfactory system) is closely connected to odor qualities. Here we report on a neural network model of the olfactory system that can predict glomerular activity from odorant molecule structures. We also report on the learning and prediction ability of the proposed model.

  4. Predicting olfactory receptor neuron responses from odorant structure

    Directory of Open Access Journals (Sweden)

    Hähnel Melanie

    2007-05-01

    Full Text Available Abstract Background Olfactory receptors work at the interface between the chemical world of volatile molecules and the perception of scent in the brain. Their main purpose is to translate chemical space into information that can be processed by neural circuits. Assuming that these receptors have evolved to cope with this task, the analysis of their coding strategy promises to yield valuable insight in how to encode chemical information in an efficient way. Results We mimicked olfactory coding by modeling responses of primary olfactory neurons to small molecules using a large set of physicochemical molecular descriptors and artificial neural networks. We then tested these models by recording in vivo receptor neuron responses to a new set of odorants and successfully predicted the responses of five out of seven receptor neurons. Correlation coefficients ranged from 0.66 to 0.85, demonstrating the applicability of our approach for the analysis of olfactory receptor activation data. The molecular descriptors that are best-suited for response prediction vary for different receptor neurons, implying that each receptor neuron detects a different aspect of chemical space. Finally, we demonstrate that receptor responses themselves can be used as descriptors in a predictive model of neuron activation. Conclusion The chemical meaning of molecular descriptors helps understand structure-response relationships for olfactory receptors and their "receptive fields". Moreover, it is possible to predict receptor neuron activation from chemical structure using machine-learning techniques, although this is still complicated by a lack of training data.

  5. The olfactory thalamus: unanswered questions about the role of the mediodorsal thalamic nucleus in olfaction

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    Emmanuelle eCourtiol

    2015-09-01

    Full Text Available The mediodorsal thalamic nucleus (MDT is a higher order thalamic nucleus and its role in cognition is increasingly well established. Interestingly, components of the MDT also have a somewhat unique sensory function as they link primary olfactory cortex to orbitofrontal associative cortex. In fact, anatomical evidence firmly demonstrates that the MDT receives direct input from primary olfactory areas including the piriform cortex and has dense reciprocal connections with the orbitofrontal cortex. The functions of this olfactory pathway have been poorly explored but lesion, imaging, and electrophysiological studies suggest that these connections may be involved in olfactory processing including odor perception, discrimination, learning, and attention. However, many important questions regarding the MDT and olfaction remain unanswered. Our goal here is not only to briefly review the existing literature but also to highlight some of the remaining questions that need to be answered to better define the role(s of the MDT in olfactory processing.

  6. The olfactory thalamus: unanswered questions about the role of the mediodorsal thalamic nucleus in olfaction.

    Science.gov (United States)

    Courtiol, Emmanuelle; Wilson, Donald A

    2015-01-01

    The mediodorsal thalamic nucleus (MDT) is a higher order thalamic nucleus and its role in cognition is increasingly well established. Interestingly, components of the MDT also have a somewhat unique sensory function as they link primary olfactory cortex to orbitofrontal associative cortex. In fact, anatomical evidence firmly demonstrates that the MDT receives direct input from primary olfactory areas including the piriform cortex and has dense reciprocal connections with the orbitofrontal cortex. The functions of this olfactory pathway have been poorly explored but lesion, imaging, and electrophysiological studies suggest that these connections may be involved in olfactory processing including odor perception, discrimination, learning, and attention. However, many important questions regarding the MDT and olfaction remain unanswered. Our goal here is not only to briefly review the existing literature but also to highlight some of the remaining questions that need to be answered to better define the role(s) of the MDT in olfactory processing.

  7. Prenatal imprinting of postnatal specific appetites and feeding behavior.

    Science.gov (United States)

    Nicolaïdis, Stylianos

    2008-10-01

    Epigenetic influences on the fetus's genotype have been shown to occur during intrauterine life. Experimentally imposed extracellular dehydration in pregnant rats (a model for human hyponatremia caused by gravidic vomiting) brings about a dramatic enhancement of salt appetite not only in the dam, but also in offspring when they reach adulthood. This phenomenon has been verified in human newborn infants and adults whose mothers experienced nausea and/or vomiting during pregnancy. Alcohol consumption during pregnancy enhances its palatability for the offspring. Ingestion of olfactory test substances like anise or carrot by the mother during pregnancy gives rise to a preference for the same testants in the offspring. Under- or overnutrition in the pregnant mother appears to play a role in reprogramming the postnatal regulation of both feeding and fat reserves in offspring. Both maternal under- and overnutrition during pregnancy predispose the offspring to later development of obesity and type 2 diabetes mellitus. A careful examination of the systems concerned with the regulation of food intake, and the neurosubstances involved in such regulation, reveals some of the mechanisms by which maternal nutritional status can affect the offspring and their food-related behaviors.

  8. Olfactory habituation in Drosophila-odor encoding and its plasticity in the antennal lobe.

    Science.gov (United States)

    Twick, Isabell; Lee, John Anthony; Ramaswami, Mani

    2014-01-01

    A ubiquitous feature of an animal's response to an odorant is that it declines when the odorant is frequently or continuously encountered. This decline in olfactory response, termed olfactory habituation, can have temporally or mechanistically different forms. The neural circuitry of the fruit fly Drosophila melanogaster's olfactory system is well defined in terms of component cells, which are readily accessible to functional studies and genetic manipulation. This makes it a particularly useful preparation for the investigation of olfactory habituation. In addition, the insect olfactory system shares many architectural and functional similarities with mammalian olfactory systems, suggesting that olfactory mechanisms in insects may be broadly relevant. In this chapter, we discuss the likely mechanisms of olfactory habituation in context of the participating cell types, their connectivity, and their roles in sensory processing. We overview the structure and function of key cell types, the mechanisms that stimulate them, and how they transduce and process odor signals. We then consider how each stage of olfactory processing could potentially contribute to behavioral habituation. After this, we overview a variety of recent mechanistic studies that point to an important role for potentiation of inhibitory synapses in the primary olfactory processing center, the antennal lobe, in driving the reduced response to familiar odorants. Following the discussion of mechanisms for short- and long-term olfactory habituation, we end by considering how these mechanisms may be regulated by neuromodulators, which likely play key roles in the induction, gating, or suppression of habituated behavior, and speculate on the relevance of these processes for other forms of learning and memory.

  9. Medicinal Marijuana: A Legitimate Appetite Stimulant?

    OpenAIRE

    Aquino, Glen

    2005-01-01

    Medicinal marijuana has been at the center of controversy for the treatment of cancer cachexia and AIDS related weight loss. Dronabinol, the oral form of marijuana, was approved for appetite stimulation, but its variability in absorption has led researchers to believe that smoked marijuana may be more effective. The discovery of endocannabinoids and their receptors has drawn attention from the research community, and as a result, marijuana’s role in appetite stimulation is clearer. Marijua...

  10. Glutamate and GABA in appetite regulation

    OpenAIRE

    Teresa Cardoso Delgado

    2013-01-01

    Appetite is regulated by a coordinated interplay between gut, adipose tissue and brain. A primary site for the regulation of appetite is the hypothalamus where interaction between orexigenic neurons, expressing Neuropeptide Y/Agouti-related protein, and anorexigenic neurons, expressing Pro-opiomelanocortin cocaine/Amphetamine-related transcript, controls energy homeostasis. Within the hypothalamus, several peripheral signals have been shown to modulate the activity of these neurons, including...

  11. Glutamate and GABA in Appetite Regulation

    OpenAIRE

    Delgado, Teresa C.

    2013-01-01

    Appetite is regulated by a coordinated interplay between gut, adipose tissue, and brain. A primary site for the regulation of appetite is the hypothalamus where interaction between orexigenic neurons, expressing Neuropeptide Y/Agouti-related protein, and anorexigenic neurons, expressing Pro-opiomelanocortin cocaine/Amphetamine-related transcript, controls energy homeostasis. Within the hypothalamus, several peripheral signals have been shown to modulate the activity of these neurons, includin...

  12. The pharmacology of human appetite expression.

    Science.gov (United States)

    Halford, Jason C G; Cooper, Gillian D; Dovey, Terence M

    2004-04-01

    The discovery of the adiposity signal leptin a decade ago revolutionised our understanding of the hypothalamic mechanisms underpinning the central control of ingestive behaviour. Subsequently, the structure and function of various hypothalamic peptide systems (Neuropeptide Y (NPY), Orexins, Melanocortins, Cocaine and Amphetamine Regulating Transcript (CART), Galanin/Galanin Like Peptides (GALP) and endocannabinoids) have been characterised in detail in rodent models. The therapeutic benefit of targeting these systems remains to be discovered. More is becoming known about the pharmacological potential of peripheral, meal-induced, episodic endogenous peptides. Hormones such as Cholecystokinin (CCK), Gastrin Releasing Peptides (GRP), Glucagon-Like Peptide I (GLP-1) Enterostatin, Amylin, Peptide YY (PYY) and Ghrelin are released prior to, during and/or after a meal, controlling intake and subjective feelings of appetite (hunger and satiety). In addition, there is an expanding body of literature detailing the effects of a wide variety of drugs on human appetite and food intake. Some of these drugs act upon CNS monoamine systems such as Serotonin (5-HT). Dopamine (DA) and Noradrenaline (NA), have long been implicated in appetite regulation. Detailed examination of both the effect of agonising endogenous gut peptide systems and the effect of various monoaminergic drugs on the expression of human appetite can provide a greater understanding of mechanisms underpinning normal appetite regulation. However, such an understanding must be based on knowledge of the effect of the treatment on meal size, eating rate, meal pattern, food choice and the subjective experience of appetite flux (hunger and satiety), and notjust food intake.

  13. Long-Lasting Metabolic Imbalance Related to Obesity Alters Olfactory Tissue Homeostasis and Impairs Olfactory-Driven Behaviors.

    Science.gov (United States)

    Lacroix, Marie-Christine; Caillol, Monique; Durieux, Didier; Monnerie, Régine; Grebert, Denise; Pellerin, Luc; Repond, Cendrine; Tolle, Virginie; Zizzari, Philippe; Baly, Christine

    2015-10-01

    Obesity is associated with chronic food intake disorders and binge eating. Food intake relies on the interaction between homeostatic regulation and hedonic signals among which, olfaction is a major sensory determinant. However, its potential modulation at the peripheral level by a chronic energy imbalance associated to obese status remains a matter of debate. We further investigated the olfactory function in a rodent model relevant to the situation encountered in obese humans, where genetic susceptibility is juxtaposed on chronic eating disorders. Using several olfactory-driven tests, we compared the behaviors of obesity-prone Sprague-Dawley rats (OP) fed with a high-fat/high-sugar diet with those of obese-resistant ones fed with normal chow. In OP rats, we reported 1) decreased odor threshold, but 2) poor olfactory performances, associated with learning/memory deficits, 3) decreased influence of fasting, and 4) impaired insulin control on food seeking behavior. Associated with these behavioral modifications, we found a modulation of metabolism-related factors implicated in 1) electrical olfactory signal regulation (insulin receptor), 2) cellular dynamics (glucorticoids receptors, pro- and antiapoptotic factors), and 3) homeostasis of the olfactory mucosa and bulb (monocarboxylate and glucose transporters). Such impairments might participate to the perturbed daily food intake pattern that we observed in obese animals. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  16. Olfactory bulb size, odor discrimination and magnetic insensitivity in hummingbirds.

    Science.gov (United States)

    Ioalé, P; Papi, F

    1989-05-01

    Relative olfactory bulb size with respect to telencephalic hemispheres (olfactory ratio) was measured in five species of hummingbirds. Trochiliformes were found to be next to last among 25 avian orders with respect to olfactory bulb development. One hummingbird species, the White-vented Violetear (Colibri serrirostris), was trained in a successive go/no-go discrimination task, and learned to feed or not to feed from a container dependent on the olfactory stimuli associated with it. Test birds learned to discriminate amyl acetate vs. turpentine essence, jasmine essence vs. lavender essence, eucalyptus essence vs. no odor, beta-ionone vs. no odor, carvone vs. eucalyptol. In contrast, 1-phenylethanol vs. beta-ionone discrimination, two odorants which appear similar to humans, was unsuccessful. Using a similar procedure, attempts were made to condition a White-vented Violetear and a Versicolored Emerald (Amazilia versicolor) to magnetic stimuli. The birds were unable to discriminate between a normal field and an oscillating field (square wave, 1 Hz, amplitude +/- 0.40 G).

  17. Olfactory signaling in insects.

    Science.gov (United States)

    Wicher, Dieter

    2015-01-01

    The detection of volatile chemical information in insects is performed by three types of olfactory receptors, odorant receptors (ORs), specific gustatory receptor (GR) proteins for carbon dioxide perception, and ionotropic receptors (IRs) which are related to ionotropic glutamate receptors. All receptors form heteromeric assemblies; an OR complex is composed of an odor-specific OrX protein and a coreceptor (Orco). ORs and GRs have a 7-transmembrane topology as for G protein-coupled receptors, but they are inversely inserted into the membrane. Ligand-gated ion channels (ionotropic receptors) and ORs operate as IRs activated by volatile chemical cues. ORs are evolutionarily young receptors, and they first appear in winged insects and seem to be evolved to allow an insect to follow sparse odor tracks during flight. In contrast to IRs, the ORs can be sensitized by repeated subthreshold odor stimulation. This process involves metabotropic signaling. Pheromone receptors are especially sensitive and require an accessory protein to detect the lipid-derived pheromone molecules. Signaling cascades involved in pheromone detection depend on intensity and duration of stimuli and underlie a circadian control. Taken together, detection and processing of volatile information in insects involve ionotropic as well as metabotropic mechanisms. Here, I review the cellular signaling events associated with detection of cognate ligands by the different types of odorant receptors.

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

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    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.

  19. Which solvent for olfactory testing?

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    Philpott, C M; Goodenough, P C; Wolstenholme, C R; Murty, G E

    2004-12-01

    The physical properties of any carrier can deteriorate over time and thus alter the results in any olfactory test. The aim of this study was to evaluate clinically potential solvents as a clean odourless carrier for olfactory testing. Sweet almond oil, pure coconut oil, pure peach kernel oil, dipropylene glycol, monopropylene glycol, mineral oil and silicone oil were studied. The experimentation was conducted in two parts. First, an olfactory device was used to conduct air through the solvents on a weekly basis using a cohort of six volunteers to assess the perceived odour of each solvent at weekly intervals. Secondly a cross-reference test was performed using small bottled solutions of phenylethyl-alcohol and 1-butanol in 10-fold dilutions to compare any perceived difference in concentrations over a period of 8 weeks. We concluded that mineral oil is the most suitable carrier for the purpose of olfactory testing, possessing many desirable characteristics of an olfactory solvent, and that silicone oil may provide a suitable alternative for odorants with which it is miscible.

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

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    Julia Negroni

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

  1. The short neuropeptide F modulates olfactory sensitivity of Bactrocera dorsalis upon starvation.

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    Jiang, Hong-Bo; Gui, Shun-Hua; Xu, Li; Pei, Yu-Xia; Smagghe, Guy; Wang, Jin-Jun

    2017-05-01

    The insect short neuropeptide F (sNPF) family has been shown to modulate diverse physiological processes, such as feeding, appetitive olfactory behavior, locomotion, sleep homeostasis and hormone release. In this study, we identified the sNPF (BdsNPF) and its receptor (BdsNPFR) in an important agricultural pest, the oriental fruit fly Bactrocera dorsalis (Hendel). Afterwards, the receptor cDNA was functionally expressed in Chinese hamster ovary cell lines. Activation of BdsNPFR by sNPF peptides caused an increase in intracellular calcium ions, with a 50% effective concentration values at the nanomolar level. As indicated by qPCR, the BdsNPF and BdsNPFR transcripts were mainly detected in the central nervous system and antennae, and they showed significantly starvation-induced expression patterns. Furthermore, we found that the starved flies had an increased electroantennogram response compared to the normally fed flies. However, this enhanced olfactory sensitivity was reversed when we decreased the expression of BdsNPF by double-stranded RNA injection in adults. We concluded that sNPF plays an important role in modulating the olfactory sensitivity of B. dorsalis upon starvation. Our results will facilitate the understanding of the regulation of early olfactory processing in B. dorsalis. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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

    2012-01-01

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

  3. Appetitive behavioral traits and stimulus intensity influence maintenance of conditioned fear

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    Megan eOlshavsky

    2013-12-01

    Full Text Available Individual differences in appetitive learning have long been reported, and generally divide into two classes of responses: cue- vs. reward-directed. The influence of cue- vs. reward-directed phenotypes on aversive cue processing, is less well understood. In the current study, we first categorized rats based on their predominant cue-directed orienting responses during appetitive Pavlovian conditioning. Then, we investigated the effect of phenotype on the latency to exit a familiar dark environment and enter an unfamiliar illuminated open field. Next, we examined whether the two phenotypes responded differently to a reconsolidation updating manipulation (retrieval+extinction after fear conditioning. We report that the rats with a cue-directed (orienting phenotype differentially respond to the open field, and also to fear conditioning, depending on US-intensity. In addition, our findings suggest that, regardless of appetitive phenotype or shock intensity, extinction within the reconsolidation window prevents spontaneous recovery of fear.

  4. Appetitive traits from infancy to adolescence: using behavioral and neural measures to investigate obesity risk.

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    Carnell, Susan; Benson, Leora; Pryor, Katherine; Driggin, Elissa

    2013-09-10

    We come into the world with enduring predispositions towards food, which interact with environmental factors to influence our eating behaviors and weight trajectories. But our fates are not sealed - by learning more about this process we can identify ways to intervene. To advance this goal this we need to be able to assess appetitive traits such as food cue responsiveness and satiety sensitivity at different developmental stages. Assessment methods might include behavioral measures (e.g. eating behavior tests, psychometric questionnaires), but also biomarkers such as brain responses to food cues measured using fMRI. Evidence from infants, children and adolescents suggests that these indices of appetite differ not only with body weight, but also with familial obesity risk as assessed by parent weight, which reflects both genetic and environmental influences, and may provide a useful predictor of obesity development. Behavioral and neural approaches have great potential to inform each other: examining eating behavior can help us identify meaningful appetitive endophenotypes whose neural bases can be probed, while increasing knowledge of the shared neurobiology underlying appetite, obesity, and related behaviors and disorders may ultimately lead to innovative generalized interventions. Another challenge will be to combine comprehensive behavioral and neural assessments of appetitive traits with measures of relevant genetic and environmental factors within long-term prospective studies. This approach may help to identify the biobehavioral precursors of obesity, and lay the foundations for targeted neurobehavioral interventions that can interrupt the pathway to excess weight.

  5. Olfactory dysfunction in Down's Syndrome.

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    Murphy, C; Jinich, S

    1996-01-01

    Down's Syndrome subjects over 40 years old show neuropathology similar to that of Alzheimer's disease. The olfactory system is particularly vulnerable in Alzheimer's disease, both anatomically and functionally. Several measures of sensory and cognitive functioning were studied in the older Down's Syndrome patient, with the hypothesis of significant olfactory dysfunction. Participants were 23 Down's subjects, and 23 controls. The Dementia Rating Scale showed mean scores of 103 for Down's subjects and 141 for controls. Down's subjects showed significant deficits in odor detection threshold, odor identification, and odor recognition memory. Normal performance in a taste threshold task, similar to the olfactory threshold task in subject demands, suggested that the Down's syndrome subjects' poor performance was not due to task demands. Deficits in olfaction may provide a sensitive and early indicator of the deterioration and progression of the brain in older subjects with Down's Syndrome.

  6. Aging in the olfactory system.

    Science.gov (United States)

    Mobley, Arie S; Rodriguez-Gil, Diego J; Imamura, Fumiaki; Greer, Charles A

    2014-02-01

    With advancing age, the ability of humans to detect and discriminate odors declines. In light of the rapid progress in analyzing molecular and structural correlates of developing and adult olfactory systems, the paucity of information available on the aged olfactory system is startling. A rich literature documents the decline of olfactory acuity in aged humans, but the underlying cellular and molecular mechanisms are largely unknown. Using animal models, preliminary work is beginning to uncover differences between young and aged rodents that may help address the deficits seen in humans, but many questions remain unanswered. Recent studies of odorant receptor (OR) expression, synaptic organization, adult neurogenesis, and the contribution of cortical representation during aging suggest possible underlying mechanisms and new research directions.

  7. Glutamate and GABA in appetite regulation

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    Teresa Cardoso Delgado

    2013-08-01

    Full Text Available Appetite is regulated by a coordinated interplay between gut, adipose tissue and brain. A primary site for the regulation of appetite is the hypothalamus where interaction between orexigenic neurons, expressing Neuropeptide Y/Agouti-related protein, and anorexigenic neurons, expressing Pro-opiomelanocortin cocaine/Amphetamine-related transcript, controls energy homeostasis. Within the hypothalamus, several peripheral signals have been shown to modulate the activity of these neurons, including the orexigenic peptide ghrelin and the anorexigenic hormones insulin and leptin. In addition to the accumulated knowledge on neuropeptide signaling, presence and function of amino acid neurotransmitters in key hypothalamic neurons brought a new light into appetite regulation. Therefore, the principal aim of this review will be to describe the current knowledge of the role of amino acid neurotransmitters in the mechanism of neuronal activation during appetite regulation and the associated neuronal-astrocytic metabolic coupling mechanisms.Glutamate and GABA dominate synaptic transmission in the hypothalamus and administration of their receptors agonists into hypothalamic nuclei stimulates feeding. By using 13C High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance spectroscopy based analysis, the Cerdán group has shown that increased neuronal firing in mice hypothalamus, as triggered by appetite during the feeding-fasting paradigm, may stimulate the use of lactate as neuronal fuel leading to increased astrocytic glucose consumption and glycolysis. Moreover, fasted mice showed increased hypothalamic [2-13C]GABA content, which may be explained by the existence of GABAergic neurons in key appetite regulation hypothalamic nuclei. Interestingly, increased [2-13C]GABA concentration in the hypothalamus of fasted animals appears to result mainly from reduction in GABA metabolizing pathways, rather than increased GABA synthesis by augmented activity of the

  8. Glutamate and GABA in Appetite Regulation.

    Science.gov (United States)

    Delgado, Teresa C

    2013-01-01

    Appetite is regulated by a coordinated interplay between gut, adipose tissue, and brain. A primary site for the regulation of appetite is the hypothalamus where interaction between orexigenic neurons, expressing Neuropeptide Y/Agouti-related protein, and anorexigenic neurons, expressing Pro-opiomelanocortin cocaine/Amphetamine-related transcript, controls energy homeostasis. Within the hypothalamus, several peripheral signals have been shown to modulate the activity of these neurons, including the orexigenic peptide ghrelin and the anorexigenic hormones insulin and leptin. In addition to the accumulated knowledge on neuropeptide signaling, presence and function of amino acid neurotransmitters in key hypothalamic neurons brought a new light into appetite regulation. Therefore, the principal aim of this review will be to describe the current knowledge of the role of amino acid neurotransmitters in the mechanism of neuronal activation during appetite regulation and the associated neuronal-astrocytic metabolic coupling mechanisms. Glutamate and GABA dominate synaptic transmission in the hypothalamus and administration of their receptors agonists into hypothalamic nuclei stimulates feeding. By using (13)C High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance spectroscopy based analysis, the Cerdán group has shown that increased neuronal firing in mice hypothalamus, as triggered by appetite during the feeding-fasting paradigm, may stimulate the use of lactate as neuronal fuel leading to increased astrocytic glucose consumption and glycolysis. Moreover, fasted mice showed increased hypothalamic [2-(13)C]GABA content, which may be explained by the existence of GABAergic neurons in key appetite regulation hypothalamic nuclei. Interestingly, increased [2-(13)C]GABA concentration in the hypothalamus of fasted animals appears to result mainly from reduction in GABA metabolizing pathways, rather than increased GABA synthesis by augmented activity of the glutamate

  9. Modeling appetitive Pavlovian-instrumental interactions in mice.

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    O'Connor, Eoin C; Stephens, David N; Crombag, Hans S

    2010-10-01

    In appetitive Pavlovian associative learning, a stimulus (conditioned stimulus, CS) that has been associated with the delivery of a reinforcing event (unconditioned stimulus, US; e.g., food) can subsequently elicit or modulate goal-directed instrumental behaviors. For example, a Pavlovian CS can serve to reinforce (novel) instrumental behavior (conditioned reinforcement or CRf), or it can energize and potentiate ongoing instrumental responses when presented non-contingently (Pavlovian-instrumental transfer or PIT). Notably, these different effects of a Pavlovian CS on instrumental behavior are mediated by dissociable psychological and neurobiological mechanisms. Given the critical role that Pavlovian-instrumental interactions play in regulating motivated behavior and maladaptive manifestations of motivation such as eating disorders and addictions, understanding the underlying psychological and neurobiological mechanisms will be important. This unit describes behavioral protocols that produce robust and reliable PIT and CRf in mice and that open the door for future studies using transgenic approaches into the molecular mechanisms underlying associative learning and motivation.

  10. 10-minute consultation Olfactory loss

    Institute of Scientific and Technical Information of China (English)

    E Ofo; B O'Reilly; A O'Doherty

    2007-01-01

    @@ A 65 year old man presents with loss of smell and altered taste,affecting his appetite and food intake. He had an upper respiratory tract infection before the onset of symptoms nine months ago.Initially, normal odours were distorted, followed by a constant foul smell for three months, and then complete loss of smell.

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

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    Eduardo Blanco-Hernández

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

  12. Odor Memory Stability after Reinnervation of the Olfactory Bulb

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    Blanco-Hernández, Eduardo; Valle-Leija, Pablo; Zomosa-Signoret, Viviana; Drucker-Colín, René; Vidaltamayo, Román

    2012-01-01

    The olfactory system, particularly the olfactory epithelium, presents a unique opportunity to study the regenerative capabilities of the brain, because of its ability to recover after damage. In this study, we ablated olfactory sensory neurons with methimazole and followed the anatomical and functional recovery of circuits expressing genetic markers for I7 and M72 receptors (M72-IRES-tau-LacZ and I7-IRES-tau-GFP). Our results show that 45 days after methimazole-induced lesion, axonal projections to the bulb of M72 and I7 populations are largely reestablished. Furthermore, regenerated glomeruli are re-formed within the same areas as those of control, unexposed mice. This anatomical regeneration correlates with functional recovery of a previously learned odorant-discrimination task, dependent on the cognate ligands for M72 and I7. Following regeneration, mice also recover innate responsiveness to TMT and urine. Our findings show that regeneration of neuronal circuits in the olfactory system can be achieved with remarkable precision and underscore the importance of glomerular organization to evoke memory traces stored in the brain. PMID:23071557

  13. Olfactory dysfunction in Alzheimer’s disease

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    Zou YM

    2016-04-01

    Full Text Available Yong-ming Zou, Da Lu, Li-ping Liu, Hui-hong Zhang, Yu-ying Zhou Department of Neurology, Tianjin Huanhu Hospital, Tianjin, People’s Republic of China Abstract: Alzheimer’s disease (AD is a common neurodegenerative disorder with the earliest clinical symptom of olfactory dysfunction, which is a potential clinical marker for AD severity and progression. However, many questions remain unanswered. This article reviews relevant research on olfactory dysfunction in AD and evaluates the predictive value of olfactory dysfunction for the epidemiological, pathophysiological, and clinical features of AD, as well as for the conversion of cognitive impairment to AD. We summarize problems of existing studies and provide a useful reference for further studies in AD olfactory dysfunction and for clinical applications of olfactory testing. Keywords: olfactory dysfunction, Alzheimer’s disease, olfactory testing, progress

  14. Developmental programming of appetite/satiety.

    Science.gov (United States)

    Ross, Michael G; Desai, Mina

    2014-01-01

    Obesity is often attributed to a Western lifestyle, a high-fat diet and decreased activity. While these factors certainly contribute to adult obesity, compelling data from our laboratory and others indicate that this explanation is oversimplified. Recent studies strongly argue that maternal/fetal under- or overnutrition predisposes the offspring to become hyperphagic and increases the risk of later obesity. Both infants small for gestational age (SGA) or infants born to obese mothers who consume a high-fat diet are at a markedly increased risk of adult obesity. Specific alterations in the fetal metabolic/energy environment directly influence the development of appetite regulatory pathways. Specifically, SGA infants demonstrate (1) impaired satiety and anorexigenic cell signaling, (2) enhanced cellular orexigenic responses, (3) programmed dysfunction of neuroprogenitor cell proliferation/differentiation, and (4) increased expression of appetite (NPY) versus satiety (POMC) neurons. In both hypothalamic tissue and ex vivo culture, SGA newborns exhibit increased levels of the nutrient sensor SIRT1, signifying reduced energy, whereas maternal high-fat-exposed newborns exhibit reduced levels of pAMPK, signifying energy excess. Via downstream regulation of bHLH neuroproliferation (Hes1) and neurodifferentiation factors (Mash1, Ngn3), neurogenesis is biased toward orexigenic and away from anorexigenic neurons, resulting in excess appetite, reduced satiety and development of obesity. Despite the developmental programming of appetite neurogenesis, the potential for neuronal remodeling raises the opportunity for novel interventions.

  15. An Olfactory Cinema: Smelling Perfume

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    Jiaying Sim

    2014-09-01

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

  16. Aberrant Effective Connectivity in Schizophrenia Patients During Appetitive Conditioning

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    Andreea Oliviana Diaconescu

    2011-01-01

    Full Text Available It has recently been suggested that schizophrenia involves dysfunction in brain connectivity at a neural level, and a dysfunction in reward processing at a behavioural level. The purpose of the present study was to link these two levels of analyses by examining effective connectivity patterns between brain regions mediating reward learning in patients with schizophrenia and healthy, age-matched controls. To this aim, we used functional magnetic resonance imaging (fMRI and galvanic skin recordings (GSR while patients and controls performed an appetitive conditioning experiment with visual cues as the conditioned (CS stimuli, and monetary reward as the appetitive unconditioned stimulus (US. Based on explicit stimulus contingency ratings, conditioning occurred in both groups; however, based on implicit, physiological GSR measures, patients failed to show differences between CS+ and CS- conditions. Healthy controls exhibited increased blood-oxygen-level dependent (BOLD activity across striatal, hippocampal and prefrontal regions and increased effective connectivity from the ventral striatum (VS to the orbitofrontal cortex (OFC BA 11 in the CS+ compared to the CS- condition. Compared to controls, patients showed increased BOLD activity across a similar network of brain regions, and increased effective connectivity from the striatum to hippocampus and prefrontal regions in the CS- compared to the CS+ condition. The findings of increased BOLD activity and effective connectivity in response to the CS- in patients with schizophrenia offer insight into the aberrant assignment of motivational salience to non-reinforced stimuli during conditioning that is thought to accompany schizophrenia.

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

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    Antje Haehner

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

  18. 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.

  19. Role of gut nutrient sensing in stimulating appetite and conditioning food preferences

    Science.gov (United States)

    Ackroff, Karen

    2012-01-01

    The discovery of taste and nutrient receptors (chemosensors) in the gut has led to intensive research on their functions. Whereas oral sugar, fat, and umami taste receptors stimulate nutrient appetite, these and other chemosensors in the gut have been linked to digestive, metabolic, and satiating effects that influence nutrient utilization and inhibit appetite. Gut chemosensors may have an additional function as well: to provide positive feedback signals that condition food preferences and stimulate appetite. The postoral stimulatory actions of nutrients are documented by flavor preference conditioning and appetite stimulation produced by gastric and intestinal infusions of carbohydrate, fat, and protein. Recent findings suggest an upper intestinal site of action, although postabsorptive nutrient actions may contribute to flavor preference learning. The gut chemosensors that generate nutrient conditioning signals remain to be identified; some have been excluded, including sweet (T1R3) and fatty acid (CD36) sensors. The gut-brain signaling pathways (neural, hormonal) are incompletely understood, although vagal afferents are implicated in glutamate conditioning but not carbohydrate or fat conditioning. Brain dopamine reward systems are involved in postoral carbohydrate and fat conditioning but less is known about the reward systems mediating protein/glutamate conditioning. Continued research on the postoral stimulatory actions of nutrients may enhance our understanding of human food preference learning. PMID:22442194

  20. Role of gut nutrient sensing in stimulating appetite and conditioning food preferences.

    Science.gov (United States)

    Sclafani, Anthony; Ackroff, Karen

    2012-05-15

    The discovery of taste and nutrient receptors (chemosensors) in the gut has led to intensive research on their functions. Whereas oral sugar, fat, and umami taste receptors stimulate nutrient appetite, these and other chemosensors in the gut have been linked to digestive, metabolic, and satiating effects that influence nutrient utilization and inhibit appetite. Gut chemosensors may have an additional function as well: to provide positive feedback signals that condition food preferences and stimulate appetite. The postoral stimulatory actions of nutrients are documented by flavor preference conditioning and appetite stimulation produced by gastric and intestinal infusions of carbohydrate, fat, and protein. Recent findings suggest an upper intestinal site of action, although postabsorptive nutrient actions may contribute to flavor preference learning. The gut chemosensors that generate nutrient conditioning signals remain to be identified; some have been excluded, including sweet (T1R3) and fatty acid (CD36) sensors. The gut-brain signaling pathways (neural, hormonal) are incompletely understood, although vagal afferents are implicated in glutamate conditioning but not carbohydrate or fat conditioning. Brain dopamine reward systems are involved in postoral carbohydrate and fat conditioning but less is known about the reward systems mediating protein/glutamate conditioning. Continued research on the postoral stimulatory actions of nutrients may enhance our understanding of human food preference learning.

  1. Mechanisms of attention for appetitive and aversive outcomes in Pavlovian conditioning.

    Science.gov (United States)

    Austin, A J; Duka, T

    2010-11-12

    Different mechanisms of attention controlling learning have been proposed in appetitive and aversive conditioning. The aim of the present study was to compare attention and learning in a Pavlovian conditioning paradigm using visual stimuli of varying predictive value of either monetary reward (appetitive conditioning; 10p or 50p) or blast of white noise (aversive conditioning; 97 dB or 102 dB). Outcome values were matched across the two conditions with regard to their emotional significance. Sixty-four participants were allocated to one of the four conditions matched for age and gender. All participants underwent a discriminative learning task using pairs of visual stimuli that signalled a 100%, 50%, or 0% probability of receiving an outcome. Learning was measured using a 9-point Likert scale of expectancy of the outcome, while attention using an eyetracker device. Arousal and emotional conditioning were also evaluated. Dwell time was greatest for the full predictor in the noise groups, while in the money groups attention was greatest for the partial predictor over the other two predictors. The progression of learning was the same for both groups. These findings suggest that in aversive conditioning attention is driven by the predictive salience of the stimulus while in appetitive conditioning attention is error-driven, when emotional value of the outcome is comparable.

  2. Taste matters - effects of bypassing oral stimulation on hormone and appetite responses.

    Science.gov (United States)

    Spetter, Maartje S; Mars, Monica; Viergever, Max A; de Graaf, Cees; Smeets, Paul A M

    2014-10-01

    The interaction between oral and gastric signals is an important part of food intake regulation. Previous studies suggest that bypassing oral stimulation diminishes the suppression of hunger and increases gastric emptying rate. However, the role of appetite hormones, like cholecystokinin-8 and ghrelin, in this process is still unclear. Our objective was to determine the contributions of gastric and oral stimulation to subsequent appetite and hormone responses and their effect on ad libitum intake. Fourteen healthy male subjects (age 24.6±3.8y, BMI 22.3±1.6kg/m(2)) completed a randomized, single-blinded, cross-over experiment with 3 treatment-sessions: 1) Stomach distention: naso-gastric infusion of 500mL/0kJ water, 2) Stomach distention with caloric content: naso-gastric infusion of 500mL/1770kJ chocolate milk, and 3) Stomach distention with caloric content and oral exposure: oral administration of 500mL/1770kJ chocolate milk. Changes in appetite ratings and plasma glucose, insulin, cholecystokinin-8, and active and total ghrelin concentrations were measured at fixed time-points up to 30min after infusion or oral administration. Subsequently, subjects consumed an ad libitum buffet meal. Oral administration reduced appetite ratings more than both naso-gastric infusions (Pdecreased total ghrelin concentrations more than ingestion (all P0.05). Thus, gastric infusion of nutrients induces greater appetite hormone responses than ingestion does. These data provide novel and additional evidence that bypassing oral stimulation not only affects the appetite profile but also increases anorexigenic hormone responses, probably driven in part by faster gastric emptying. This confirms the idea that learned associations between sensory characteristics and associated metabolic consequences serve to adapt hormone responses to nutrient content. These findings underscore the importance of oral stimulation in the regulation of food intake.

  3. Short neuropeptide F acts as a functional neuromodulator for olfactory memory in Kenyon cells of Drosophila mushroom bodies.

    Science.gov (United States)

    Knapek, Stephan; Kahsai, Lily; Winther, Asa M E; Tanimoto, Hiromu; Nässel, Dick R

    2013-03-20

    In insects, many complex behaviors, including olfactory memory, are controlled by a paired brain structure, the so-called mushroom bodies (MB). In Drosophila, the development, neuroanatomy, and function of intrinsic neurons of the MB, the Kenyon cells, have been well characterized. Until now, several potential neurotransmitters or neuromodulators of Kenyon cells have been anatomically identified. However, whether these neuroactive substances of the Kenyon cells are functional has not been clarified yet. Here we show that a neuropeptide precursor gene encoding four types of short neuropeptide F (sNPF) is required in the Kenyon cells for appetitive olfactory memory. We found that activation of Kenyon cells by expressing a thermosensitive cation channel (dTrpA1) leads to a decrease in sNPF immunoreactivity in the MB lobes. Targeted expression of RNA interference against the sNPF precursor in Kenyon cells results in a highly significant knockdown of sNPF levels. This knockdown of sNPF in the Kenyon cells impairs sugar-rewarded olfactory memory. This impairment is not due to a defect in the reflexive sugar preference or odor response. Consistently, knockdown of sNPF receptors outside the MB causes deficits in appetitive memory. Altogether, these results suggest that sNPF is a functional neuromodulator released by Kenyon cells.

  4. Centrifugal innervation of the mammalian olfactory bulb.

    Science.gov (United States)

    Matsutani, Shinji; Yamamoto, Noboru

    2008-12-01

    Although it has been known for decades that the mammalian olfactory bulb receives a substantial number of centrifugal inputs from other regions of the brain, relatively few data have been available on the function of the centrifugal olfactory system. Knowing the role of the centrifugal projection and how it works is of critical importance to fully understanding olfaction. The centrifugal fibers can be classified into two groups, a group that release neuromodulators, such as noradrenaline, serotonin, or acetylcholine, and a group originating in the olfactory cortex. Accumulating evidence suggests that centrifugal neuromodulatory inputs are associated with acquisition of odor memory. Because the distribution of the terminals on these fibers is diffuse and widespread, the neuromodulatory inputs must affect diverse subsets of bulbar neurons at the same time. In contrast, knowledge of the role of centrifugal fibers from the olfactory cortical areas is limited. Judging from recent morphological evidence, these fibers may modify the activity of neurons located in sparse and discrete loci in the olfactory bulb. Given the modular organization of the olfactory bulb, centrifugal fibers from the olfactory cortex may help coordinate the activities of restricted subsets of neurons belonging to distinct functional modules in an odor-specific manner. Because the olfactory cortex receives inputs from limbic and neocortical areas in addition to inputs from the bulb, the centrifugal inputs from the cortex can modulate odor processing in the bulb in response to non-olfactory as well as olfactory cues.

  5. Appetitive Aggression in Women: Comparing Male and Female War Combatants

    Directory of Open Access Journals (Sweden)

    Danie eMeyer-Parlapanis

    2016-01-01

    Full Text Available Appetitive aggression refers to positive feelings being associated with the perpetration of violent behavior and has been shown to provide resilience against the development of PTSD in combatants returning from the battlefield. Until this point, appetitive aggression has been primarily researched in males. This study investigates appetitive aggression in females. Female and male combatants and civilians from Burundi were assessed for levels of appetitive aggression. In contrast to non-combatants, no sex difference in appetitive aggression could be detected for combatants. Furthermore, each of the female and male combatant groups displayed substantially higher levels of appetitive aggression than each of the male and female civilian control groups. This study demonstrates that in violent contexts, such as armed conflict, in which individuals perpetrate numerous aggressive acts against others, the likelihood for an experience of appetitive aggression increases- regardless of whether the individuals are male or female.

  6. Profiling of olfactory receptor gene expression in whole human olfactory mucosa.

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    Christophe Verbeurgt

    Full Text Available Olfactory perception is mediated by a large array of olfactory receptor genes. The human genome contains 851 olfactory receptor gene loci. More than 50% of the loci are annotated as nonfunctional due to frame-disrupting mutations. Furthermore haplotypic missense alleles can be nonfunctional resulting from substitution of key amino acids governing protein folding or interactions with signal transduction components. Beyond their role in odor recognition, functional olfactory receptors are also required for a proper targeting of olfactory neuron axons to their corresponding glomeruli in the olfactory bulb. Therefore, we anticipate that profiling of olfactory receptor gene expression in whole human olfactory mucosa and analysis in the human population of their expression should provide an opportunity to select the frequently expressed and potentially functional olfactory receptors in view of a systematic deorphanization. To address this issue, we designed a TaqMan Low Density Array (Applied Biosystems, containing probes for 356 predicted human olfactory receptor loci to investigate their expression in whole human olfactory mucosa tissues from 26 individuals (13 women, 13 men; aged from 39 to 81 years, with an average of 67±11 years for women and 63±12 years for men. Total RNA isolation, DNase treatment, RNA integrity evaluation and reverse transcription were performed for these 26 samples. Then 384 targeted genes (including endogenous control genes and reference genes specifically expressed in olfactory epithelium for normalization purpose were analyzed using the same real-time reverse transcription PCR platform. On average, the expression of 273 human olfactory receptor genes was observed in the 26 selected whole human olfactory mucosa analyzed, of which 90 were expressed in all 26 individuals. Most of the olfactory receptors deorphanized to date on the basis of sensitivity to known odorant molecules, which are described in the literature, were

  7. Olfactory neuroblastoma: A case report

    Science.gov (United States)

    USLU, GONCA HANEDAN; CANYILMAZ, EMINE; ZENGIN, AHMET YASAR; MUNGAN, SEVDEGUL; YONEY, ADNAN; BAHADIR, OSMAN; GOCMEZ, HUSEYIN

    2015-01-01

    Olfactory neuroblastoma (ON) is a rare type of malignant neoplasm originating from the olfactory neuroepithelial cells of the nasal cavity. ON is also known as esthesioneuroblastoma or neuroendocrine carcinoma. The malignancy accounts for <3% of tumors originating in the nasal cavity. Through the nasal cavity, ON may infiltrate the sinuses, the orbit and the cranium. The tumor is characterized by a pattern of slow growth and local recurrences. Treatment options are surgical excision or surgery combined with a radiotherapy (RT) and/or chemotherapy combination treatment. The present study reports the case of a 69-year-old patient with a mass in the nasal cavity who was treated by combined surgical excision and RT. The literature for ON and the treatment of the tumor are also discussed. PMID:26788185

  8. Appetite and Energy Intake in Humans

    DEFF Research Database (Denmark)

    Sørensen, Lone Brinkmann

    on appetite sensations, ad libitum energy intake and gastro-intestinal satiety hormones. 3. To compare the effect of dark chocolate versus milk chocolate on appetite sensations and ad libitum energy intake. In paper 1, the participants who received sucrose supplements had lower ratings of fullness and higher....... The data 7 indicated that there was no difference in fat absorption after the two fat rich meals, although this was not measured directly. In paper 3, higher ratings of satiety and lower ratings of hunger and prospective consumption were recorded after consumption of the dark chocolate than after the milk...... chocolate. Ratings of the desire to eat something sweet, salty, fatty, and savoury were all lower after consumption of the dark chocolate than after the milk chocolate. The results suggest that it could be beneficial to use dark chocolate as a substitute for milk chocolate. In summary, these results suggest...

  9. Appetite and Energy Intake in Humans

    DEFF Research Database (Denmark)

    Sørensen, Lone Brinkmann

    on appetite sensations, ad libitum energy intake and gastro-intestinal satiety hormones. 3. To compare the effect of dark chocolate versus milk chocolate on appetite sensations and ad libitum energy intake. In paper 1, the participants who received sucrose supplements had lower ratings of fullness and higher...... ratings of prospective food consumption between lunch and dinner, and after dinner than the participants who received artificial sweetener supplements. Both groups had a high energy intake during the test day, but the sucrose supplements induced a higher energy intake, compared with the artificial...... sweetener supplements. In paper 2, the modified triacylglycerol salatrim did not reduce energy intake, compared with traditional fat, despite slightly higher ratings of fullness during the salatrim test day. The slight difference in fullness was not due to differences in gastro-intestinal satiety hormones...

  10. Latina mothers' influences on child appetite regulation.

    Science.gov (United States)

    Silva Garcia, Karina; Power, Thomas G; Fisher, Jennifer Orlet; O'Connor, Teresia M; Hughes, Sheryl O

    2016-08-01

    Parents influence child weight through interactions that shape the development of child eating behaviors. In this study we examined the association between maternal autonomy promoting serving practices and child appetite regulation. We predicted that maternal autonomy promoting serving practices would be positively associated with child appetite regulation. Participants were low-income Latino children-a group at high risk for the development of childhood obesity. A total of 186 low-income Latina mothers and their 4-5 year old children came to a laboratory on two separate days. On the first day, mothers and children chose foods for a meal from a buffet and were audio/videotaped so that maternal autonomy promoting serving practices could be later coded. On the second day, children completed the Eating in the Absence of Hunger (EAH) task to measure child appetite regulation. Mothers also completed the Child Eating Behavior Questionnaire (CEBQ) to measure other aspects of child appetite regulation (food responsiveness, satiety responsiveness, and emotional overeating). Maternal autonomy promotion during serving was assessed using seven separate measures of child and maternal behavior. Principal components analyses of these serving measures yielded three components: allows child choice, child serves food, and mother does not restrict. Consistent with hypotheses, maternal autonomy promoting serving practices (i.e., allows child choice and does not restrict) were negatively associated with maternal reports of child food responsiveness and emotional overeating (CEBQ). The results for the EAH task were more complex-mothers who were autonomy promoting in their serving practices had children who ate the most in the absence of hunger, but this linear effect was moderated somewhat by a quadratic effect, with moderate levels of autonomy promotion during serving associated with the greatest child EAH.

  11. 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.

  12. Molecule capture by olfactory antennules: mantis shrimp.

    Science.gov (United States)

    Stacey, Mark T; Mead, Kristina S; Koehl, Mimi A R

    2002-01-01

    A critical step in the process of olfaction is the movement of odorant molecules from the environment to the surface of a chemosensory structure. Many marine crustaceans capture odorant molecules with arrays of chemosensory sensilla (aesthetascs) on antennules that they flick through the water. We developed a model to calculate molecule flux to the surfaces of aesthetascs in order to study how the size, aesthetasc spacing, and flick kinematics of olfactory antennules affect their performance in capturing molecules from the surrounding water. Since the three-dimensional geometry of an aesthetasc-bearing antennule is complex, dynamically-scaled physical models can often provide an efficient method of determining the fluid velocity field through the array. Here we present a method to optimize the incorporation of such measured velocity vector fields into a numerical simulation of the advection and diffusion of odorants to aesthetasc surfaces. Furthermore, unlike earlier models of odorant interception by antennae, our model incorporates odorant concentration distributions that have been measured in turbulent ambient flows. By applying our model to the example of the olfactory antennules of mantis shrimp, we learned that flicking velocity can have profound effects on odorant flux to the aesthetascs if they operate in the speed range in which the leakiness of the gaps between the aesthetascs to fluid movement is sensitive to velocity. This sensitivity creates an asymmetry in molecule fluxes between outstroke and return stroke, which results in an antennule taking discrete samples in space and time, i.e. "sniffing". As stomatopods grow and their aesthetasc Reynolds number increases, the aesthetasc arrangement on the antennule changes in a way that maintains these asymmetries in leakiness and molecule flux between the outstroke and return stroke, allowing the individual to continue to take discrete samples as it develops.

  13. How partial reinforcement of food cues affects the extinction and reacquisition of appetitive responses. A new model for dieting success?

    Science.gov (United States)

    van den Akker, Karolien; Havermans, Remco C; Bouton, Mark E; Jansen, Anita

    2014-10-01

    Animals and humans can easily learn to associate an initially neutral cue with food intake through classical conditioning, but extinction of learned appetitive responses can be more difficult. Intermittent or partial reinforcement of food cues causes especially persistent behaviour in animals: after exposure to such learning schedules, the decline in responding that occurs during extinction is slow. After extinction, increases in responding with renewed reinforcement of food cues (reacquisition) might be less rapid after acquisition with partial reinforcement. In humans, it may be that the eating behaviour of some individuals resembles partial reinforcement schedules to a greater extent, possibly affecting dieting success by interacting with extinction and reacquisition. Furthermore, impulsivity has been associated with less successful dieting, and this association might be explained by impulsivity affecting the learning and extinction of appetitive responses. In the present two studies, the effects of different reinforcement schedules and impulsivity on the acquisition, extinction, and reacquisition of appetitive responses were investigated in a conditioning paradigm involving food rewards in healthy humans. Overall, the results indicate both partial reinforcement schedules and, possibly, impulsivity to be associated with worse extinction performance. A new model of dieting success is proposed: learning histories and, perhaps, certain personality traits (impulsivity) can interfere with the extinction and reacquisition of appetitive responses to food cues and they may be causally related to unsuccessful dieting.

  14. SLEEP AND OLFACTORY CORTICAL PLASTICITY

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    Dylan eBarnes

    2014-04-01

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

  15. Hypothalamic neuropeptides and the regulation of appetite.

    Science.gov (United States)

    Parker, Jennifer A; Bloom, Stephen R

    2012-07-01

    Neuropeptides released by hypothalamic neurons play a major role in the regulation of feeding, acting both within the hypothalamus, and at other appetite regulating centres throughout the brain. Where classical neurotransmitters signal only within synapses, neuropeptides diffuse over greater distances affecting both nearby and distant neurons expressing the relevant receptors, which are often extrasynaptic. As well as triggering a behavioural output, neuropeptides also act as neuromodulators: altering the response of neurons to both neurotransmitters and circulating signals of nutrient status. The mechanisms of action of hypothalamic neuropeptides with established roles in feeding, including melanin-concentrating hormone (MCH), the orexins, α-melanocyte stimulating hormone (α-MSH), agouti-gene related protein (AgRP), neuropeptide Y, and oxytocin, are reviewed in this article, with emphasis laid on both their effects on appetite regulating centres throughout the brain, and on examining the evidence for their physiological roles. In addition, evidence for the involvement of several putative appetite regulating hypothalamic neuropeptides is assessed including, ghrelin, cocaine and amphetamine-regulated transcript (CART), neuropeptide W and the galanin-like peptides. This article is part of a Special Issue entitled 'Central control of Food Intake'.

  16. Developmental programing of thirst and sodium appetite.

    Science.gov (United States)

    Mecawi, Andre S; Macchione, Ana F; Nuñez, Paula; Perillan, Carmen; Reis, Luis C; Vivas, Laura; Arguelles, Juan

    2015-04-01

    Thirst and sodium appetite are the sensations responsible for the motivated behaviors of water and salt intake, respectively, and both are essential responses for the maintenance of hydromineral homeostasis in animals. These sensations and their related behaviors develop very early in the postnatal period in animals. Many studies have demonstrated several pre- and postnatal stimuli that are responsible for the developmental programing of thirst and sodium appetite and, consequently, the pattern of water and salt intake in adulthood in need-free or need-induced conditions. The literature systematically reports the involvement of dietary changes, hydromineral and cardiovascular challenges, renin-angiotensin system and steroid hormone disturbances, and lifestyle in these developmental factors. Therefore, this review will address how pre- and postnatal challenges can program lifelong thirst and sodium appetite in animals and humans, as well as which neuroendocrine substrates are involved. In addition, the possible epigenetic molecular mechanisms responsible for the developmental programing of drinking behavior, the clinical implications of hydromineral disturbances during pre- and postnatal periods, and the developmental origins of adult hydromineral behavior will be discussed.

  17. Stimulants for the control of hedonic appetite

    Directory of Open Access Journals (Sweden)

    Alison Sally Poulton

    2016-04-01

    Full Text Available The focus of this paper is treatment of obesity in relation to the management of hedonic appetite. Obesity is a complex condition which may be potentiated by excessive reward seeking in combination with executive functioning deficits that impair cognitive control of behaviour. Stimulant medications address both reward deficiency and enhance motivation, as well as suppressing appetite. They have long been recognised to be effective for treating obesity. However, stimulants can be abused for their euphoric effect. They induce euphoria via the same neural pathway that underlies their therapeutic effect in obesity. For this reason they have generally not been endorsed for use in obesity. Among the stimulants, only phentermine (either alone or in combination with topiramate and bupropion (which has stimulant-like properties and is used in combination with naltrexone, are approved by the United States Food and Drug Administration (FDA for obesity, although dexamphetamine and methylpenidate are approved and widely used for treating attention deficit hyperactivity disorder (ADHD in adults and children. Experience gained over many years in the treatment of ADHD demonstrates that with careful dose titration, stimulants can be used safely. In obesity, improvement in mood and executive functioning could assist with the lifestyle changes necessary for weight control, acting synergistically with appetite suppression. The obesity crisis has reached the stage that strong consideration should be given to adequate utilisation of this effective and inexpensive class of drug.

  18. Roles of olfactory system dysfunction in depression.

    Science.gov (United States)

    Yuan, Ti-Fei; Slotnick, Burton M

    2014-10-01

    The olfactory system is involved in sensory functions, emotional regulation and memory formation. Olfactory bulbectomy in rat has been employed as an animal model of depression for antidepressant discovery studies for many years. Olfaction is impaired in animals suffering from chronic stress, and patients with clinical depression were reported to have decreased olfactory function. It is believed that the neurobiological bases of depression might include dysfunction in the olfactory system. Further, brain stimulation, including nasal based drug delivery could provide novel therapies for management of depression.

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

    Directory of Open Access Journals (Sweden)

    Derya R Shimshek

    2005-11-01

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

  20. Disruption of adult neurogenesis in the olfactory bulb affects social interaction but not maternal behavior

    Directory of Open Access Journals (Sweden)

    Claudia E Feierstein

    2010-12-01

    Full Text Available Adult-born neurons arrive to the olfactory bulb and integrate into the existing circuit throughout life. Despite the prevalence of this phenomenon, its functional impact is still poorly understood. Recent studies point to the importance of newly generated neurons to olfactory learning and memory. Adult neurogenesis is regulated by a variety of factors, notably by instances related to reproductive behavior, such as exposure to mating partners, pregnancy and lactation, and exposure to offspring. To study the contribution of olfactory neurogenesis to maternal behavior and social recognition, here we selectively disrupted olfactory bulb neurogenesis using focal irradiation of the subventricular zone in adult female mice. We show that reduction of olfactory neurogenesis results in an abnormal social interaction pattern with male, but not female, conspecifics; we suggest that this effect could result from inability to detect or discriminate male odors and could therefore have implications for the recognition of potential mating partners. Disruption of olfactory bulb neurogenesis, however, neither impaired maternal-related behaviors, nor did it affect the ability of mothers to discriminate their own progeny from others.

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2006-07-19

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

  3. Immediate Extinction Causes a Less Durable Loss of Performance than Delayed Extinction following Either Fear or Appetitive Conditioning

    Science.gov (United States)

    Woods, Amanda M.; Bouton, Mark E.

    2008-01-01

    Five experiments with rat subjects compared the effects of immediate and delayed extinction on the durability of extinction learning. Three experiments examined extinction of fear conditioning (using the conditioned emotional response method), and two experiments examined extinction of appetitive conditioning (using the food-cup entry method). In…

  4. Computational modeling suggests distinct, location-specific function of norepinephrine in olfactory bulb and piriform cortex

    Directory of Open Access Journals (Sweden)

    Licurgo ede Almeida

    2015-06-01

    Full Text Available Noradrenergic modulation from the locus coerulus is often associated with the regulation of sensory signal-to-noise ratio. In the olfactory system, noradrenergic modulation affects both bulbar and cortical processing, and has been show to modulate the detection of low concentration stimuli. We here implemented a computational model of the olfactory bulb and piriform cortex, based on known experimental results, to explore how noradrenergic modulation in the olfactory bulb and piriform cortex interact to regulate odor processing. We show that as predicted by behavioral experiments in our lab, norepinephrine can play a critical role in modulating the detection and associative learning of very low odor concentrations. Our simulations show that bulbar norepinephrine serves to pre-process odor representations to facilitate cortical learning, but not recall. We observe the typical non-uniform dose – response functions described for norepinephrine modulation and show that these are imposed mainly by bulbar, but not cortical processing.

  5. Computational modeling suggests distinct, location-specific function of norepinephrine in olfactory bulb and piriform cortex.

    Science.gov (United States)

    de Almeida, Licurgo; Reiner, Seungdo J; Ennis, Matthew; Linster, Christiane

    2015-01-01

    Noradrenergic modulation from the locus coerulus is often associated with the regulation of sensory signal-to-noise ratio. In the olfactory system, noradrenergic modulation affects both bulbar and cortical processing, and has been shown to modulate the detection of low concentration stimuli. We here implemented a computational model of the olfactory bulb and piriform cortex, based on known experimental results, to explore how noradrenergic modulation in the olfactory bulb and piriform cortex interact to regulate odor processing. We show that as predicted by behavioral experiments in our lab, norepinephrine can play a critical role in modulating the detection and associative learning of very low odor concentrations. Our simulations show that bulbar norepinephrine serves to pre-process odor representations to facilitate cortical learning, but not recall. We observe the typical non-uniform dose-response functions described for norepinephrine modulation and show that these are imposed mainly by bulbar, but not cortical processing.

  6. Odor-Induced Neuronal Rhythms in the Olfactory Bulb Are Profoundly Modified in ob/ob Obese Mice

    Science.gov (United States)

    Chelminski, Yan; Magnan, Christophe; Luquet, Serge H.; Everard, Amandine; Meunier, Nicolas; Gurden, Hirac; Martin, Claire

    2017-01-01

    Leptin, the product of the Ob(Lep) gene, is a peptide hormone that plays a major role in maintaining the balance between food intake and energy expenditure. In the brain, leptin receptors are expressed by hypothalamic cells but also in the olfactory bulb, the first central structure coding for odors, suggesting a precise function of this hormone in odor-evoked activities. Although olfaction plays a key role in feeding behavior, the ability of the olfactory bulb to integrate the energy-related signal leptin is still missing. Therefore, we studied the fate of odor-induced activity in the olfactory bulb in the genetic context of leptin deficiency using the obese ob/ob mice. By means of an odor discrimination task with concomitant local field potential recordings, we showed that ob/ob mice perform better than wild-type (WT) mice in the early stage of the task. This behavioral gain of function was associated in parallel with profound changes in neuronal oscillations in the olfactory bulb. The distribution of the peaks in the gamma frequency range was shifted toward higher frequencies in ob/ob mice compared to WT mice before learning. More notably, beta oscillatory activity, which has been shown previously to be correlated with olfactory discrimination learning, was longer and stronger in expert ob/ob mice after learning. Since oscillations in the olfactory bulb emerge from mitral to granule cell interactions, our results suggest that cellular dynamics in the olfactory bulb are deeply modified in ob/ob mice in the context of olfactory learning.

  7. Houseflies : Effects of age on olfactory responses

    NARCIS (Netherlands)

    Kelling, FJ; den Otter, CJ; Sommeijer, MJ; Francke, PJ

    1998-01-01

    The olfactory system of sexually immature 1-day-old flies is already functional. No clear differences exist between the responses of their olfactory cells and those of sexually mature flies to amylacetate, S-methylphenol, 2-pentanone and R(+)-limonene. However, the sensitivity to 1-octen-3-ol is low

  8. Olfactory regulation of mosquito-host interactions

    NARCIS (Netherlands)

    Zwiebel, L.J.; Takken, W.

    2004-01-01

    Mosquitoes that act as disease vectors rely upon olfactory cues to direct several important behaviors that are fundamentally involved in establishing their overall vectorial capacity. Of these, the propensity to select humans for blood feeding is arguably the most important of these olfactory driven

  9. DNA methylation adjusts the specificity of memories depending on the learning context and promotes relearning in honeybees

    Directory of Open Access Journals (Sweden)

    Stephanie D Biergans

    2016-09-01

    Full Text Available The activity of the epigenetic writers DNA methyltransferases (Dnmts after olfactory reward conditioning is important for both stimulus-specific long-term memory (LTM formation and extinction. It, however, remains unknown which components of memory formation Dnmts regulate (e.g. associative vs. non-associative and in what context (e.g. varying training conditions. Here we address these aspects in order to clarify the role of Dnmt-mediated DNA methylation in memory formation. We used a pharmacological Dnmt inhibitor and classical appetitive conditioning in the honeybee Apis mellifera, a well characterized model for classical conditioning. We quantified the effect of DNA methylation on naïve odour and sugar responses, and on responses following olfactory reward conditioning. We show that (1 Dnmts do not influence naïve odour or sugar responses, (2 Dnmts do not affect the learning of new stimuli, but (3 Dnmts influence odour-coding, i.e. 'correct' (stimulus-specific LTM formation. Particularly, Dnmts reduce memory specificity when experience is low (one-trial training, and increase memory specificity when experience is high (multiple-trial training, generating an ecologically more useful response to learning. (4 In reversal learning conditions, Dnmts are involved in regulating both excitatory (re-acquisition and inhibitory (forgetting processes.

  10. DNA Methylation Adjusts the Specificity of Memories Depending on the Learning Context and Promotes Relearning in Honeybees

    Science.gov (United States)

    Biergans, Stephanie D.; Claudianos, Charles; Reinhard, Judith; Galizia, C. G.

    2016-01-01

    The activity of the epigenetic writers DNA methyltransferases (Dnmts) after olfactory reward conditioning is important for both stimulus-specific long-term memory (LTM) formation and extinction. It, however, remains unknown which components of memory formation Dnmts regulate (e.g., associative vs. non-associative) and in what context (e.g., varying training conditions). Here, we address these aspects in order to clarify the role of Dnmt-mediated DNA methylation in memory formation. We used a pharmacological Dnmt inhibitor and classical appetitive conditioning in the honeybee Apis mellifera, a well characterized model for classical conditioning. We quantified the effect of DNA methylation on naïve odor and sugar responses, and on responses following olfactory reward conditioning. We show that (1) Dnmts do not influence naïve odor or sugar responses, (2) Dnmts do not affect the learning of new stimuli, but (3) Dnmts influence odor-coding, i.e., ‘correct’ (stimulus-specific) LTM formation. Particularly, Dnmts reduce memory specificity when experience is low (one-trial training), and increase memory specificity when experience is high (multiple-trial training), generating an ecologically more useful response to learning. (4) In reversal learning conditions, Dnmts are involved in regulating both excitatory (re-acquisition) and inhibitory (forgetting) processes. PMID:27672359

  11. Differential associative training enhances olfactory acuity in Drosophila melanogaster.

    Science.gov (United States)

    Barth, Jonas; Dipt, Shubham; Pech, Ulrike; Hermann, Moritz; Riemensperger, Thomas; Fiala, André

    2014-01-29

    Training can improve the ability to discriminate between similar, confusable stimuli, including odors. One possibility of enhancing behaviorally expressed discrimination (i.e., sensory acuity) relies on differential associative learning, during which animals are forced to detect the differences between similar stimuli. Drosophila represents a key model organism for analyzing neuronal mechanisms underlying both odor processing and olfactory learning. However, the ability of flies to enhance fine discrimination between similar odors through differential associative learning has not been analyzed in detail. We performed associative conditioning experiments using chemically similar odorants that we show to evoke overlapping neuronal activity in the fly's antennal lobes and highly correlated activity in mushroom body lobes. We compared the animals' performance in discriminating between these odors after subjecting them to one of two types of training: either absolute conditioning, in which only one odor is reinforced, or differential conditioning, in which one odor is reinforced and a second odor is explicitly not reinforced. First, we show that differential conditioning decreases behavioral generalization of similar odorants in a choice situation. Second, we demonstrate that this learned enhancement in olfactory acuity relies on both conditioned excitation and conditioned inhibition. Third, inhibitory local interneurons in the antennal lobes are shown to be required for behavioral fine discrimination between the two similar odors. Fourth, differential, but not absolute, training causes decorrelation of odor representations in the mushroom body. In conclusion, differential training with similar odors ultimately induces a behaviorally expressed contrast enhancement between the two similar stimuli that facilitates fine discrimination.

  12. Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants.

    Science.gov (United States)

    Guerrieri, Fernando J; d'Ettorre, Patrizia; Devaud, Jean-Marc; Giurfa, Martin

    2011-10-01

    Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and non-rewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which individually harnessed ants learn an association between odour and reward. When the antennae of an ant are stimulated with sucrose solution, the insect extends its maxilla-labium to absorb the solution (maxilla-labium extension response). We differentially conditioned ants to discriminate between two long-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72 h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior to conditioning. Cycloheximide did not impair acquisition of either short-term memory (10 min) or early and late mid-term memories (1 or 12 h). These results show that, upon olfactory learning, ants form different memories with variable molecular bases. While short- and mid-term memories do not require protein synthesis, long-term memories are stabilised via protein synthesis. Our behavioural protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants.

  13. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

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

  14. A Closer Look at Acid-Base Olfactory Titrations

    Science.gov (United States)

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

    2005-01-01

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

  15. Detection of Olfactory Dysfunction Using Olfactory Event Related Potentials in Young Patients with Multiple Sclerosis

    Science.gov (United States)

    Caminiti, Fabrizia; De Salvo, Simona; De Cola, Maria Cristina; Russo, Margherita; Bramanti, Placido; Marino, Silvia; Ciurleo, Rosella

    2014-01-01

    Background Several studies reported olfactory dysfunction in patients with multiple sclerosis. The estimate of the incidence of olfactory deficits in multiple sclerosis is uncertain; this may arise from different testing methods that may be influenced by patients' response bias and clinical, demographic and cognitive features. Aims To evaluate objectively the olfactory function using Olfactory Event Related Potentials. Materials and Methods We tested the olfactory function of 30 patients with relapsing remitting multiple sclerosis (mean age of 36.03±6.96 years) and of 30 age, sex and smoking–habit matched healthy controls by using olfactory potentials. A selective and controlled stimulation of the olfactory system to elicit the olfactory event related potentials was achieved by a computer-controlled olfactometer linked directly with electroencephalograph. Relationships between olfactory potential results and patients' clinical characteristics, such as gender, disability status score, disease-modifying therapy, and disease duration, were evaluated. Results Seven of 30 patients did not show olfactory event related potentials. Sixteen of remaining 23 patients had a mean value of amplitude significantly lower than control group (p<0.01). The presence/absence of olfactory event related potentials was associated with dichotomous expanded disability status scale (p = 0.0433), as well as inversely correlated with the disease duration (r = −0.3641, p = 0.0479). Conclusion Unbiased olfactory dysfunction of different severity found in multiple sclerosis patients suggests an organic impairment which could be related to neuroinflammatory and/or neurodegenerative processes of olfactory networks, supporting the recent findings on neurophysiopathology of disease. PMID:25047369

  16. Detection of olfactory dysfunction using olfactory event related potentials in young patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Fabrizia Caminiti

    Full Text Available Several studies reported olfactory dysfunction in patients with multiple sclerosis. The estimate of the incidence of olfactory deficits in multiple sclerosis is uncertain; this may arise from different testing methods that may be influenced by patients' response bias and clinical, demographic and cognitive features.To evaluate objectively the olfactory function using Olfactory Event Related Potentials.We tested the olfactory function of 30 patients with relapsing remitting multiple sclerosis (mean age of 36.03±6.96 years and of 30 age, sex and smoking-habit matched healthy controls by using olfactory potentials. A selective and controlled stimulation of the olfactory system to elicit the olfactory event related potentials was achieved by a computer-controlled olfactometer linked directly with electroencephalograph. Relationships between olfactory potential results and patients' clinical characteristics, such as gender, disability status score, disease-modifying therapy, and disease duration, were evaluated.Seven of 30 patients did not show olfactory event related potentials. Sixteen of remaining 23 patients had a mean value of amplitude significantly lower than control group (p<0.01. The presence/absence of olfactory event related potentials was associated with dichotomous expanded disability status scale (p = 0.0433, as well as inversely correlated with the disease duration (r = -0.3641, p = 0.0479.Unbiased olfactory dysfunction of different severity found in multiple sclerosis patients suggests an organic impairment which could be related to neuroinflammatory and/or neurodegenerative processes of olfactory networks, supporting the recent findings on neurophysiopathology of disease.

  17. Preliminary Modeling and Simulation Study on Olfactory Cell Sensation

    Science.gov (United States)

    Zhou, Jun; Yang, Wei; Chen, Peihua; Liu, Qingjun; Wang, Ping

    2009-05-01

    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.

  18. Steroid Hormone (20-Hydroxyecdysone) Modulates the Acquisition of Aversive Olfactory Memories in Pollen Forager Honeybees

    Science.gov (United States)

    Geddes, Lisa H.; McQuillan, H. James; Aiken, Alastair; Vergoz, Vanina; Mercer, Alison R.

    2013-01-01

    Here, we examine effects of the steroid hormone, 20-hydroxyecdysone (20-E), on associative olfactory learning in the honeybee, "Apis mellifera." 20-E impaired the bees' ability to associate odors with punishment during aversive conditioning, but did not interfere with their ability to associate odors with a food reward (appetitive…

  19. Appetitive and aversive classical conditioning of female sexual response

    NARCIS (Netherlands)

    S. Both; E. Laan; M. Spiering; T. Nilsson; S. Oomens; W. Everaerd

    2008-01-01

    INTRODUCTION: There is only limited evidence for appetitive classical conditioning of female sexual response, and to date modulation of female sexual response by aversive conditioning has not been studied. AIM: The aim of this article is to study appetitive and aversive classical conditioning of sex

  20. [Prevention and management of appetite loss during cancer chemotherapy].

    Science.gov (United States)

    Tsujimura, Hideki; Yamada, Mitsugi; Asako, Eri; Kodama, Yukako; Sato, Tsuneo; Nabeya, Yoshihiro

    2014-10-01

    Appetite loss during cancer chemotherapy may lead to malnutrition and a decreased quality of life. To overcome this problem, evidence-based guidelines have been established for chemotherapy-induced emesis and mucositis. However, unsolved issues such as taste alimentation remain. Since the clinical picture of appetite loss is complex, individual management strategies depending on the type of the disease and treatment are required.

  1. Appetitive Motivation and Negative Emotion Reactivity among Remitted Depressed Youth

    Science.gov (United States)

    Hankin, Benjamin L.; Wetter, Emily K.; Flory, Kate

    2012-01-01

    Depression has been characterized as involving altered appetitive motivation and emotional reactivity. Yet no study has examined objective indices of emotional reactivity when the appetitive/approach system is suppressed in response to failure to attain a self-relevant goal and desired reward. Three groups of youth (N = 98, ages 9-15; remitted…

  2. The role of infant appetite in extended formula feeding

    NARCIS (Netherlands)

    Syrad, H.; Jaarsveld, C.H.M. van; Wardle, J.; Llewellyn, C.H.

    2015-01-01

    OBJECTIVE: Parental decision-making around extended formula feeding (12 months+) has not been explored previously. This study tested the hypotheses that extended formula milk use (i) is associated with poorer appetite and (ii) supplements lower food intake. METHODS: Appetite was assessed with the Ch

  3. Aging & appetite : Social and physiological approaches in the elderly

    NARCIS (Netherlands)

    Mathey, M.F.A.M.

    2000-01-01

    Aging is often accompanied by anorexia of aging, described as a decline in appetite, a lower dietary intake and followed by unexplained weight loss. The present thesis described research on anorexia of aging. Focus was given to social and physiological determinants of appetite and the relationship w

  4. Age-associated changes of appetite-regulating peptides.

    Science.gov (United States)

    Akimoto, Saeko; Miyasaka, Kyoko

    2010-07-01

    Aging is associated with a progressive decrease in appetite and food intake. The reasons for the decline in food intake are multifactorial, and relate to both peripheral and central mechanisms. Current studies about the regulation of food intake suggest that there are many central mediators that control the appetite. To determine the mechanism of age-associated decrease in appetite and food intake, we focused on the age-associated changes of the suppressing and stimulatory effect of some appetite-regulating peptides. At first, we examined cholecystokinin (CCK), one of the typical appetite-suppressing factors. Although sensitivity to CCK is enhanced in old animals, the mechanism underlying this effect has not been elucidated. Next, we focused on the appetite-stimulating peptides, orexin-A, neuropeptide Y (NPY) and ghrelin, which are known to play a critical role in food intake. To determine the age-associated decrease in appetite and food intake, we compared the stimulatory effect of intracerebroventricular administration of orexin-A, NPY and ghrelin. We report the studies of the age-associated changes of appetite-regulating peptides in this review.

  5. Olfactory bulb as an alternative in neurotransplantation

    Directory of Open Access Journals (Sweden)

    Руслан Романович Новиков

    2015-05-01

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

  6. [Odor sensing system and olfactory display].

    Science.gov (United States)

    Nakamoto, Takamichi

    2014-01-01

    In this review, an odor sensing system and an olfactory display are introduced into people in pharmacy. An odor sensing system consists of an array of sensors with partially overlapping specificities and pattern recognition technique. One of examples of odor sensing systems is a halitosis sensor which quantifies the mixture composition of three volatile sulfide compounds. A halitosis sensor was realized using a preconcentrator to raise sensitivity and an electrochemical sensor array to suppress the influence of humidity. Partial least squares (PLS) method was used to quantify the mixture composition. The experiment reveals that the sufficient accuracy was obtained. Moreover, the olfactory display, which present scents to human noses, is explained. A multi-component olfactory display enables the presentation of a variety of smells. The two types of multi-component olfactory display are described. The first one uses many solenoid valves with high speed switching. The valve ON frequency determines the concentration of the corresponding odor component. The latter one consists of miniaturized liquid pumps and a surface acoustic wave (SAW) atomizer. It enables the wearable olfactory display without smell persistence. Finally, the application of the olfactory display is demonstrated. Virtual ice cream shop with scents was made as a content of interactive art. People can enjoy harmony among vision, audition and olfaction. In conclusion, both odor sensing system and olfactory display can contribute to the field of human health care.

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

    Energy Technology Data Exchange (ETDEWEB)

    Duprez, Thierry P. [Department of Radiology and Medical Imaging, Universite catholique de Louvain, Cliniques Universitaires Saint-Luc, Avenue Hippocrate, 10, 1200-Brussels (Belgium)], E-mail: Thierry.Duprez@uclouvain.be; Rombaux, Philippe [Department of Otorhinolaryngology, Universite catholique de Louvain, Cliniques Universitaires Saint-Luc, Avenue Hippocrate, 10, 1200-Brussels (Belgium)], E-mail: Philippe.Rombaux@uclouvain.be

    2010-05-15

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

  8. Afterhyperpolarization (AHP) regulates the frequency and timing of action potentials in the mitral cells of the olfactory bulb: role of olfactory experience.

    Science.gov (United States)

    Duménieu, Maël; Fourcaud-Trocmé, Nicolas; Garcia, Samuel; Kuczewski, Nicola

    2015-05-01

    Afterhyperpolarization (AHP) is a principal feedback mechanism in the control of the frequency and patterning of neuronal firing. In principal projection neurons of the olfactory bulb, the mitral cells (MCs), the AHP is produced by three separate components: classical potassium-mediated hyperpolarization, and the excitatory and inhibitory components, which are generated by the recurrent dendrodendritic synaptic transmission. Precise spike timing is involved in olfactory coding and learning, as well as in the appearance of population oscillatory activity. However, the contribution of the AHP and its components to these processes remains unknown. In this study, we demonstrate that the AHP is developed with the MC firing frequency and is dominated by the potassium component. We also show that recurrent synaptic transmission significantly modifies MC AHP and that the strength of the hyperpolarization produced by the AHP in the few milliseconds preceding the action potential (AP) emission determines MC firing frequency and AP timing. Moreover, we show that the AHP area is larger in younger animals, possibly owing to increased Ca(2+) influx during MC firing. Finally, we show that olfactory experience selectively reduces the early component of the MC AHP (under 25 msec), thus producing a modification of the AP timing limited to the higher firing frequency. On the basis of these results, we propose that the AHP, and its susceptibility to be selectively modulated by the recurrent synaptic transmission and olfactory experience, participate in odor coding and learning by modifying the frequency and pattern of MC firing.

  9. 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.

  10. Stomatin-related olfactory protein, SRO, specifically expressed in the murine olfactory sensory neurons.

    Science.gov (United States)

    Kobayakawa, Ko; Hayashi, Reiko; Morita, Kenji; Miyamichi, Kazunari; Oka, Yuichiro; Tsuboi, Akio; Sakano, Hitoshi

    2002-07-15

    We identified a stomatin-related olfactory protein (SRO) that is specifically expressed in olfactory sensory neurons (OSNs). The mouse sro gene encodes a polypeptide of 287 amino acids with a calculated molecular weight of 32 kDa. SRO shares 82% sequence similarity with the murine stomatin, 78% with Caenorhabditis elegans MEC-2, and 77% with C. elegans UNC-1. Unlike other stomatin-family genes, the sro transcript was present only in OSNs of the main olfactory epithelium. No sro expression was seen in vomeronasal neurons. SRO was abundant in most apical dendrites of OSNs, including olfactory cilia. Immunoprecipitation revealed that SRO associates with adenylyl cyclase type III and caveolin-1 in the low-density membrane fraction of olfactory cilia. Furthermore, anti-SRO antibodies stimulated cAMP production in fractionated cilia membrane. SRO may play a crucial role in modulating odorant signals in the lipid rafts of olfactory cilia.

  11. Contribution of gastroenteropancreatic appetite hormones to protein-induced satiety

    DEFF Research Database (Denmark)

    Sparre, Anita Belza; Ritz, Christian; Sørensen, Mejse Q

    2013-01-01

    (P PYY 3-36 (P = 0.03) next to the additive effect of GLP-1 (P = 0.006) on the composite appetite score. No difference was shown in ad libitum energy intake. CONCLUSION: Protein dose-dependently increased satiety and GLP-1, PYY 3-36, and glucagon......BACKGROUND: Effects of protein intake on appetite-regulating hormones and their dynamics are unclear. OBJECTIVES: We investigated the satiating effects of meals with varying protein contents and whether there was an effect of dose on appetite-regulating hormones and appetite ratings.Design: Twenty......; 14% of energy from protein), medium-high protein (MHP; 25% of energy from protein), and high protein (HP, 50% of energy from protein). Appetite ratings and blood samples were assessed every 0.5 h for 4 h. An ad libitum lunch was served 4 h after the meal. RESULTS: Protein increased dose...

  12. [Graphic method of recording olfactory disorders].

    Science.gov (United States)

    Bariliak, R A; Kitsera, A E

    1976-01-01

    The authors present a method of recording results of threshold olfactometry for substances of different neuroreceptive response (olfactory, olfactive-trigeminal and olfactive-glossopharyngeal) in the form of olfactograms. The use of a unit for comparative evaluation of the olfactory function (deciodor) made it possible to get a unit horizontal zero line on the olfactogram. The authors demonstrate olfactograms of patients with various olfactory disorders. They consider that the method of graphic recording results of comparative threshold olfactometry is a valuable differential-diagnostic test.

  13. Revisiting olfactory classical conditioning of the proboscis extension response in honey bees: a step toward standardized procedures.

    Science.gov (United States)

    Matsumoto, Yukihisa; Menzel, Randolf; Sandoz, Jean-Christophe; Giurfa, Martin

    2012-10-15

    The honey bee Apis mellifera has emerged as a robust and influential model for the study of classical conditioning thanks to the existence of a powerful Pavlovian conditioning protocol, the olfactory conditioning of the proboscis extension response (PER). In 2011, the olfactory PER conditioning protocol celebrated its 50 years since it was first introduced by Kimihisa Takeda in 1961. In this protocol, individually harnessed honey bees are trained to associate an odor with sucrose solution. The resulting olfactory learning is fast and induces robust olfactory memories that have been characterized at the behavioral, neuronal and molecular levels. Despite the success of this protocol for studying the bases of learning and memory at these different levels, innumerable procedural variants have arisen throughout the years, which render comparative analyses of behavioral performances difficult. Moreover, because even slight variations in conditioning procedures may introduce significant differences in acquisition and retention performances, we revisit olfactory PER conditioning and define here a standardized framework for experiments using this behavioral protocol. To this end, we present and discuss all the methodological steps and details necessary for successful implementation of olfactory PER conditioning.

  14. The Gut Hormones in Appetite Regulation

    Directory of Open Access Journals (Sweden)

    Keisuke Suzuki

    2011-01-01

    Full Text Available Obesity has received much attention worldwide in association with an increased risk of cardiovascular diseases, diabetes, and cancer. At present, bariatric surgery is the only effective treatment for obesity in which long-term weight loss is achieved in patients. By contrast, pharmacological interventions for obesity are usually followed by weight regain. Although the exact mechanisms of long-term weight loss following bariatric surgery are yet to be fully elucidated, several gut hormones have been implicated. Gut hormones play a critical role in relaying signals of nutritional and energy status from the gut to the central nervous system, in order to regulate food intake. Cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide-1, and oxyntomodulin act through distinct yet synergistic mechanisms to suppress appetite, whereas ghrelin stimulates food intake. Here, we discuss the role of gut hormones in the regulation of food intake and body weight.

  15. Odourant dominance in olfactory mixture processing: what makes a strong odourant?

    Science.gov (United States)

    Schubert, Marco; Sandoz, Jean-Christophe; Galizia, Giovanni; Giurfa, Martin

    2015-03-07

    The question of how animals process stimulus mixtures remains controversial as opposing views propose that mixtures are processed analytically, as the sum of their elements, or holistically, as unique entities different from their elements. Overshadowing is a widespread phenomenon that can help decide between these alternatives. In overshadowing, an individual trained with a binary mixture learns one element better at the expense of the other. Although element salience (learning success) has been suggested as a main explanation for overshadowing, the mechanisms underlying this phenomenon remain unclear. We studied olfactory overshadowing in honeybees to uncover the mechanisms underlying olfactory-mixture processing. We provide, to our knowledge, the most comprehensive dataset on overshadowing to date based on 90 experimental groups involving more than 2700 bees trained either with six odourants or with their resulting 15 binary mixtures. We found that bees process olfactory mixtures analytically and that salience alone cannot predict overshadowing. After normalizing learning success, we found that an unexpected feature, the generalization profile of an odourant, was determinant for overshadowing. Odourants that induced less generalization enhanced their distinctiveness and became dominant in the mixture. Our study thus uncovers features that determine odourant dominance within olfactory mixtures and allows the referring of this phenomenon to differences in neural activity both at the receptor and the central level in the insect nervous system.

  16. Response of appetite and potential appetite regulators following intake of high energy nutritional supplements.

    Science.gov (United States)

    Fatima, Sadia; Gerasimidis, Konstantinos; Wright, Charlotte; Tsiountsioura, Melina; Arvanitidou, Eirini-Iro; Malkova, Dalia

    2015-12-01

    The net clinical benefit of high-energy nutritional supplements (HENSDs) consumption is lower than expected. To investigate the extent to which consumption of oral HENSD in the fasted state reduces energy intake in slim females during consecutive breakfast and lunch, and whether this relates to changes in appetite and metabolic appetite regulators. Twenty three females of 24.4 ± 2.8 years with BMI of 18.2 ± 0.8 kg/m(2) consumed HENSD (2.5 MJ) or PLACEBO (0.4 MJ) in fasted state in a single blind randomized cross-over study. Appetite and metabolic rate measurements and blood collection were conducted prior to and during 240 min after the intake of the supplements. Energy intake was recorded during ad libitum buffet breakfast and lunch served 60 min and 240 min post supplementation respectively. Energy intake during breakfast was significantly (P energy intake was 1.07 ± 0.34 MJ higher in the HENSD compared to PLACEBO. Plasma concentration of CCK and PYY and insulin and were significantly (P energy expended above resting metabolic rate was significantly (P energy expenditure was not significantly different between the two trials. Oral high-energy nutritional supplements have a partial and relatively short lived suppressive action on energy intake and can be expected to increase net energy intake by approximately half the energy value of the supplement consumed. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  17. Amniotic fluid elicits appetitive responses in human newborns: fatty acids and appetitive responses.

    Science.gov (United States)

    Contreras, Carlos M; Gutiérrez-García, Ana G; Mendoza-López, Remedios; Rodríguez-Landa, Juan Francisco; Bernal-Morales, Blandina; Díaz-Marte, Cynthia

    2013-04-01

    In humans, maternal cues guide newborns to the maternal breast, and transitional cues may be present in maternal-fetal fluids. The aim of the present study was to determine the consistent presence of sensorial cues in three maternal-fetal fluids--amniotic fluid, colostrum, and milk--and test the ability of these cues to produce appetitive responses in newborns. In the analytical study, gas chromatography-mass spectrometry (GC-MS) detected eight fatty acids consistently present in the amniotic fluid, colostrum, and milk from 12 healthy volunteers, but we do not find a mammalian pheromone, identified in another mammalian species (rabbits), in another 30 volunteers. In the behavioral study, we explored the ability of amniotic fluid or its fatty acids to produce appetitive responses in 19 human newborns fluid or an artificial fatty acid mixture produced a longer duration of facial reactions that suggested appetitive (sucking) movements compared with respective vehicles (i.e., propylene glycol or centrifuged amniotic fluid with a low fatty acid content verified by GC-MS). We conclude that the fatty acids contained in amniotic fluid may constitute a transitional sensorial cue that guides newborns to the maternal breast.

  18. Cladistic Analysis of Olfactory and Vomeronasal Systems

    Science.gov (United States)

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

    2010-01-01

    Most tetrapods possess two nasal organs for detecting chemicals in their environment, which are the sensory detectors of the olfactory and vomeronasal systems. The seventies’ view that the olfactory system was only devoted to sense volatiles, whereas the vomeronasal system was exclusively specialized for pheromone detection was challenged by accumulating data showing deep anatomical and functional interrelationships between both systems. In addition, the assumption that the vomeronasal system appeared as an adaptation to terrestrial life is being questioned as well. The aim of the present work is to use a comparative strategy to gain insight in our understanding of the evolution of chemical “cortex.” We have analyzed the organization of the olfactory and vomeronasal cortices of reptiles, marsupials, and placental mammals and we have compared our findings with data from other taxa in order to better understand the evolutionary history of the nasal sensory systems in vertebrates. The olfactory and vomeronsasal cortices have been re-investigated in garter snakes (Thamnophis sirtalis), short-tailed opossums (Monodelphis domestica), and rats (Rattus norvegicus) by tracing the efferents of the main and accessory olfactory bulbs using injections of neuroanatomical anterograde tracers (dextran-amines). In snakes, the medial olfactory tract is quite evident, whereas the main vomeronasal-recipient structure, the nucleus sphaericus is a folded cortical-like structure, located at the caudal edge of the amygdala. In marsupials, which are acallosal mammals, the rhinal fissure is relatively dorsal and the olfactory and vomeronasal cortices relatively expanded. Placental mammals, like marsupials, show partially overlapping olfactory and vomeronasal projections in the rostral basal telencephalon. These data raise the interesting question of how the telencephalon has been re-organized in different groups according to the biological relevance of chemical senses. PMID:21290004

  19. Cladistic analysis of olfactory and vomeronasal systems.

    Science.gov (United States)

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

    2011-01-01

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

  20. Cladistic Analysis of Olfactory and Vomeronasal Systems

    OpenAIRE

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

    2011-01-01

    Most tetrapods possess two nasal organs for detecting chemicals in their environment, which are the sensory detectors of the olfactory and vomeronasal systems. The seventies’ view that the olfactory system was only devoted to sense volatiles, whereas the vomeronasal system was exclusively specialized for pheromone detection was challenged by accumulating data showing deep anatomical and functional interrelationships between both systems. In addition, the assumption that the vomeronasal system...

  1. Cladistic analysis of olfactory and vomeronasal systems

    OpenAIRE

    Alino eMartinez-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. 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.

  3. Dimorphic olfactory lobes in the arthropoda.

    Science.gov (United States)

    Strausfeld, Nicholas; Reisenman, Carolina E

    2009-07-01

    Specialized olfactory lobe glomeruli relating to sexual or caste differences have been observed in at least five orders of insects, suggesting an early appearance of this trait in insect evolution. Dimorphism is not limited to nocturnal species, but occurs even in insects that are known to use vision for courtship. Other than a single description, there is no evidence for similar structures occurring in the Crustacea, suggesting that the evolution of dimorphic olfactory systems may typify terrestrial arthropods.

  4. Olfactory marker protein expression is an indicator of olfactory receptor-associated events in non-olfactory tissues.

    Directory of Open Access Journals (Sweden)

    NaNa Kang

    Full Text Available Olfactory receptor (OR-associated events are mediated by well-conserved components in the olfactory epithelium, including olfactory G-protein (Golf, adenylate cyclase III (ACIII, and olfactory marker protein (OMP. The expression of ORs has recently been observed in non-olfactory tissues where they are involved in monitoring extracellular chemical cues. The large number of OR genes and their sequence similarities illustrate the need to find an effective and simple way to detect non-olfactory OR-associated events. In addition, expression profiles and physiological functions of ORs in non-olfactory tissues are largely unknown. To overcome limitations associated with using OR as a target protein, this study used OMP with Golf and ACIII as targets to screen for potential OR-mediated sensing systems in non-olfactory tissues. Here, we show using western blotting, real-time PCR, and single as well as double immunoassays that ORs and OR-associated proteins are co-expressed in diverse tissues. The results of immunohistochemical analyses showed OMP (+ cells in mouse heart and in the following cells using the corresponding marker proteins c-kit, keratin 14, calcitonin, and GFAP in mouse tissues: interstitial cells of Cajal of the bladder, medullary thymic epithelial cells of the thymus, parafollicular cells of the thyroid, and Leydig cells of the testis. The expression of ORs in OMP (+ tissues was analyzed using a refined microarray analysis and validated with RT-PCR and real-time PCR. Three ORs (olfr544, olfr558, and olfr1386 were expressed in the OMP (+ cells of the bladder and thyroid as shown using a co-immunostaining method. Together, these results suggest that OMP is involved in the OR-mediated signal transduction cascade with olfactory canonical signaling components between the nervous and endocrine systems. The results further demonstrate that OMP immunohistochemical analysis is a useful tool for identifying expression of ORs, suggesting OMP

  5. 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.

  6. Amygdala Dopamine Receptors Are Required for the Destabilization of a Reconsolidating Appetitive Memory(1,2).

    Science.gov (United States)

    Merlo, Emiliano; Ratano, Patrizia; Ilioi, Elena C; Robbins, Miranda A L S; Everitt, Barry J; Milton, Amy L

    2015-01-01

    Disrupting maladaptive memories may provide a novel form of treatment for neuropsychiatric disorders, but little is known about the neurochemical mechanisms underlying the induction of lability, or destabilization, of a retrieved consolidated memory. Destabilization has been theoretically linked to the violation of expectations during memory retrieval, which, in turn, has been suggested to correlate with prediction error (PE). It is well-established that PE correlates with dopaminergic signaling in limbic forebrain structures that are critical for emotional learning. The basolateral amygdala is a key neural substrate for the reconsolidation of pavlovian reward-related memories, but the involvement of dopaminergic mechanisms in inducing lability of amygdala-dependent memories has not been investigated. Therefore, we tested the hypothesis that dopaminergic signaling within the basolateral amygdala is required for the destabilization of appetitive pavlovian memories by investigating the effects dopaminergic and protein synthesis manipulations on appetitive memory reconsolidation in rats. Intra-amygdala administration of either the D1-selective dopamine receptor antagonist SCH23390 or the D2-selective dopamine receptor antagonist raclopride prevented memory destabilization at retrieval, thereby protecting the memory from the effects of an amnestic agent, the protein synthesis inhibitor anisomycin. These data show that dopaminergic transmission within the basolateral amygdala is required for memory labilization during appetitive memory reconsolidation.

  7. Appetite and cancer-associated anorexia: a review.

    Science.gov (United States)

    Davis, Mellar P; Dreicer, Robert; Walsh, Declan; Lagman, Ruth; LeGrand, Susan B

    2004-04-15

    Appetite is governed by peripheral hormones and central neurotransmitters that act on the arcuate nucleus of the hypothalamus and nucleus tactus solitarius of the brainstem. Cancer anorexia appears to be the result of an imbalance between neuropeptide-Y and pro-opiomelanocortin signals favoring pro-opiomelanocortin. Many of the appetite stimulants redress this imbalance. Most of our understanding of appetite neurophysiology and tumor-associated anorexia is derived from animals and has not been verified in humans. There have been few clinical trials and very little translational research on anorexia despite its prevalence in cancer.

  8. Olfactory imprinting is correlated with changes in gene expression in the olfactory epithelia of the zebrafish.

    Science.gov (United States)

    Harden, Maegan V; Newton, Lucy A; Lloyd, Russell C; Whitlock, Kathleen E

    2006-11-01

    Odors experienced as juveniles can have significant effects on the behavior of mature organisms. A dramatic example of this occurs in salmon, where the odors experienced by developing fish determine the river to which they return as adults. Further examples of olfactory memories are found in many animals including vertebrates and invertebrates. Yet, the cellular and molecular bases underlying the formation of olfactory memory are poorly understood. We have devised a series of experiments to determine whether zebrafish can form olfactory memories much like those observed in salmonids. Here we show for the first time that zebrafish form and retain olfactory memories of an artificial odorant, phenylethyl alcohol (PEA), experienced as juveniles. Furthermore, we demonstrate that exposure to PEA results in changes in gene expression within the olfactory sensory system. These changes are evident by in situ hybridization in the olfactory epithelium of the developing zebrafish. Strikingly, our analysis by in situ hybridization demonstrates that the transcription factor, otx2, is up regulated in the olfactory sensory epithelia in response to PEA. This increase is evident at 2-3 days postfertilization and is maintained in the adult animals. We propose that the changes in otx2 gene expression are manifest as an increase in the number of neuronal precursors in the cells olfactory epithelium of the odor-exposed fish. Thus, our results reveal a role for the environment in controlling gene expression in the developing peripheral nervous system. Copyright 2006 Wiley Periodicals, Inc.

  9. Functional olfactory sensory neurons housed in olfactory sensilla on the ovipositor of the hawkmoth Manduca sexta.

    Directory of Open Access Journals (Sweden)

    Christian Felix Klinner

    2016-11-01

    Full Text Available Olfactory systems evolved to detect and identify volatile chemical cues, in many cases across great distances. However, the precision of copulatory and oviposition behaviors suggest that they may be guided by olfactory cues detected by sensory systems located on or near the ovipositor. Here we present evidence of a small number of functional olfactory sensilla on the ovipositor of the hawkmoth Manduca sexta. Gene expression analysis of isolated ovipositor tissue indicated active transcription of gustatory and both classes of olfactory receptor genes. Expression of the olfactory co-receptor ORCo and the antennal ionotropic co-receptors IR8a and IR25a suggests that functional olfactory proteins may be present in the sensory structures located on the ovipositor. Scanning electron microscopy identified five to nine porous sensilla on each of the anal papillae of the ovipositor. Furthermore, HRP immunostaining indicated that these sensilla are innervated by the dendrite-like structures from multiple neurons. Finally, we functionally characterized neural responses in these sensilla using single sensillum recordings. Stimulation with a panel of 142 monomolecular odorants revealed that these sensilla indeed house functional olfactory sensory neurons (OSNs. While it remains to be determined what role these chemosensory sensilla play in odor and gustatory guided behaviors, our data clearly demonstrate an olfactory function for neurons present in M. sexta ovipositor sensilla.

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

    Directory of Open Access Journals (Sweden)

    Martinec Nováková Lenka

    2014-12-01

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

  11. Relation of the volume of the olfactory bulb to psychophysical measures of olfactory function.

    Science.gov (United States)

    Mazal, Patricia Portillo; Haehner, Antje; Hummel, Thomas

    2016-01-01

    The aim of this review is to investigate whether changes in olfactory bulb volume relate to changes in specific olfactory functions. We studied currently available peer-reviewed articles on the volume of the human olfactory bulb that also included a psychophysical measure of olfactory function. In the present review, we observed a very clear and consistent correlation between general olfactory function and olfactory bulb (OB) volume. We were not able to find a clear relationship between a specific smell component and OB volume, even when analyzing pathologic conditions separately. In some cases, changes were observed for different subtests, but these changes did not significantly correlate with OB volume or had only a borderline correlation. In other cases, we found contradictory data. Several factors may contribute to the difficulties in finding correlations with the different components of smell: (1) the OB volume may be influenced by information from olfactory receptor neurons (bottom-up effect), information from central nervous system (top-down effect) and by direct damage; (2) most pathologic conditions affect more than one area of the olfactory pathway; (3) small sample sizes of hyposmic subjects were used. We believe that it is necessary to do further studies with larger numbers of subjects to answer the currently investigated question.

  12. Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants

    DEFF Research Database (Denmark)

    Guerrieri, Fernando Javier; D'Ettorre, Patrizia; Deveaud, J-M.

    2011-01-01

    Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and nonrewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection......-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior...

  13. Memory Elicited by Courtship Conditioning Requires Mushroom Body Neuronal Subsets Similar to Those Utilized in Appetitive Memory

    Science.gov (United States)

    Montague, Shelby A.; Baker, Bruce S.

    2016-01-01

    An animal’s ability to learn and to form memories is essential for its survival. The fruit fly has proven to be a valuable model system for studies of learning and memory. One learned behavior in fruit flies is courtship conditioning. In Drosophila courtship conditioning, male flies learn not to court females during training with an unreceptive female. He retains a memory of this training and for several hours decreases courtship when subsequently paired with any female. Courtship conditioning is a unique learning paradigm; it uses a positive-valence stimulus, a female fly, to teach a male to decrease an innate behavior, courtship of the female. As such, courtship conditioning is not clearly categorized as either appetitive or aversive conditioning. The mushroom body (MB) region in the fruit fly brain is important for several types of memory; however, the precise subsets of intrinsic and extrinsic MB neurons necessary for courtship conditioning are unknown. Here, we disrupted synaptic signaling by driving a shibirets effector in precise subsets of MB neurons, defined by a collection of split-GAL4 drivers. Out of 75 lines tested, 32 showed defects in courtship conditioning memory. Surprisingly, we did not have any hits in the γ lobe Kenyon cells, a region previously implicated in courtship conditioning memory. We did find that several γ lobe extrinsic neurons were necessary for courtship conditioning memory. Overall, our memory hits in the dopaminergic neurons (DANs) and the mushroom body output neurons were more consistent with results from appetitive memory assays than aversive memory assays. For example, protocerebral anterior medial DANs were necessary for courtship memory, similar to appetitive memory, while protocerebral posterior lateral 1 (PPL1) DANs, important for aversive memory, were not needed. Overall, our results indicate that the MB circuits necessary for courtship conditioning memory coincide with circuits necessary for appetitive memory. PMID

  14. Impacts of upper respiratory tract disease on olfactory behavior of the Mojave desert tortoise

    Science.gov (United States)

    Germano, Jennifer; Van Zerr, Vanessa E.; Esque, Todd C.; Nussear, Ken E.; Lamberski, Nadine

    2014-01-01

    Upper respiratory tract disease (URTD) caused by Mycoplasma agassizii is considered a threat to desert tortoise populations that should be addressed as part of the recovery of the species. Clinical signs can be intermittent and include serous or mucoid nasal discharge and respiratory difficulty when nares are occluded. This nasal congestion may result in a loss of the olfactory sense. Turtles are known to use olfaction to identify food items, predators, and conspecifics; therefore, it is likely that URTD affects not only their physical well-being but also their behavior and ability to perform necessary functions in the wild. To determine more specifically the impact nasal discharge might have on free-ranging tortoises (Gopherus agassizii), we compared the responses of tortoises with and without nasal discharge and both positive and negative for M. agassizii antibodies to a visually hidden olfactory food stimulus and an empty control. We found that nasal discharge did reduce sense of smell and hence the ability to locate food. Our study also showed that moderate chronic nasal discharge in the absence of other clinical signs did not affect appetite in desert tortoises.

  15. Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants

    DEFF Research Database (Denmark)

    Guerrieri, Fernando Javier; D'Ettorre, Patrizia; Deveaud, J-M.;

    2011-01-01

    of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which......-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior...... synthesis, long-term memories are stabilised via protein synthesis. Our behavioural protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants....

  16. Central nervous system stimulants and drugs that suppress appetite

    DEFF Research Database (Denmark)

    Aagaard, Lise

    2014-01-01

    of the January 2012 to June 2013 publications on central nervous system stimulants and drugs that suppress appetite covers amphetamines (including metamfetamine, paramethoxyamfetamine and paramethoxymetamfetamine), fenfluramine and benfluorex, atomoxetine, methylphenidate, modafinil and armodafinil...

  17. Weight Loss Leads to Strong Increase in Appetite

    Science.gov (United States)

    ... News Releases Media Advisory Friday, October 14, 2016 Weight loss leads to strong increase in appetite Study with ... changes in caloric expenditure that typically accompany weight loss — and weight loss plateau. Findings from the analyses suggest that ...

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

    Science.gov (United States)

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

    2008-09-22

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

  19. Microanatomy and surgical relevance of the olfactory cistern.

    Science.gov (United States)

    Wang, Shou-Sen; Zheng, He-Ping; Zhang, Xiang; Zhang, Fa-Hui; Jing, Jun-Jie; Wang, Ru-Mi

    2008-01-01

    All surgical approaches to the anterior skull base involve the olfactory cistern and have the risk of damaging the olfactory nerve. The purpose of this study was to describe the microanatomical features of the olfactory cistern and discuss its surgical relevance. In this study, the olfactory cisterns of 15 formalin-fixed adult cadaveric heads were dissected using a surgical microscope. The results showed that the olfactory cistern was situated in the superficial part of the olfactory sulcus, which separated the gyrus retus from the orbital gyrus. In coronal section, the cistern was triangular in shape; its anterior part enveloped the olfactory bulbs and was high and broad; its posterior part was medial-superior to internal carotid artery and was also much broader. There were one or several openings in the inferior wall of the posterior part in 53.4% of the cisterns. The olfactory cistern communicated with the surrounding subarachnoind cisterns through these openings. The middle part of the olfactory cistern gradually narrowed down posteriorly. Most cisterns were spacious with a few fibrous trabeculas and bands between the olfactory nerves and cistern walls. However 23% of the cisterns were narrow with the cistern walls tightly encasing the olfactory nerve. There were two or three of arterial loops in each olfactory sulcus, from which long, fine olfactory arteries originated. The olfactory arteries coursed along the olfactory nerve and gave off many terminal branches to provide the main blood supply to the olfactory nerve in most cisterns, but the blood supply was in segmental style in a few cisterns. Moreover, the veins of the cistern appeared to be more segmental than the olfactory arteries in most cisterns. These results suggested that most olfactory cisterns are spacious with relatively independent blood supply, and it is reasonable to separate the olfactory tract with its independent blood supply from the frontal lobe by 1-2 cm in the subfrontal approach, the

  20. Reward signal in a recurrent circuit drives appetitive long-term memory formation.

    Science.gov (United States)

    Ichinose, Toshiharu; Aso, Yoshinori; Yamagata, Nobuhiro; Abe, Ayako; Rubin, Gerald M; Tanimoto, Hiromu

    2015-11-17

    Dopamine signals reward in animal brains. A single presentation of a sugar reward to Drosophila activates distinct subsets of dopamine neurons that independently induce short- and long-term olfactory memories (STM and LTM, respectively). In this study, we show that a recurrent reward circuit underlies the formation and consolidation of LTM. This feedback circuit is composed of a single class of reward-signaling dopamine neurons (PAM-α1) projecting to a restricted region of the mushroom body (MB), and a specific MB output cell type, MBON-α1, whose dendrites arborize that same MB compartment. Both MBON-α1 and PAM-α1 neurons are required during the acquisition and consolidation of appetitive LTM. MBON-α1 additionally mediates the retrieval of LTM, which is dependent on the dopamine receptor signaling in the MB α/β neurons. Our results suggest that a reward signal transforms a nascent memory trace into a stable LTM using a feedback circuit at the cost of memory specificity.

  1. Decoding an olfactory mechanism of kin recognition and inbreeding avoidance in a primate

    Science.gov (United States)

    2009-01-01

    Background Like other vertebrates, primates recognize their relatives, primarily to minimize inbreeding, but also to facilitate nepotism. Although associative, social learning is typically credited for discrimination of familiar kin, discrimination of unfamiliar kin remains unexplained. As sex-biased dispersal in long-lived species cannot consistently prevent encounters between unfamiliar kin, inbreeding remains a threat and mechanisms to avoid it beg explanation. Using a molecular approach that combined analyses of biochemical and microsatellite markers in 17 female and 19 male ring-tailed lemurs (Lemur catta), we describe odor-gene covariance to establish the feasibility of olfactory-mediated kin recognition. Results Despite derivation from different genital glands, labial and scrotal secretions shared about 170 of their respective 338 and 203 semiochemicals. In addition, these semiochemicals encoded information about genetic relatedness within and between the sexes. Although the sexes showed opposite seasonal patterns in signal complexity, the odor profiles of related individuals (whether same-sex or mixed-sex dyads) converged most strongly in the competitive breeding season. Thus, a strong, mutual olfactory signal of genetic relatedness appeared specifically when such information would be crucial for preventing inbreeding. That weaker signals of genetic relatedness might exist year round could provide a mechanism to explain nepotism between unfamiliar kin. Conclusion We suggest that signal convergence between the sexes may reflect strong selective pressures on kin recognition, whereas signal convergence within the sexes may arise as its by-product or function independently to prevent competition between unfamiliar relatives. The link between an individual's genome and its olfactory signals could be mediated by biosynthetic pathways producing polymorphic semiochemicals or by carrier proteins modifying the individual bouquet of olfactory cues. In conclusion, we

  2. Decoding an olfactory mechanism of kin recognition and inbreeding avoidance in a primate

    Directory of Open Access Journals (Sweden)

    Charpentier Marie JE

    2009-12-01

    Full Text Available Abstract Background Like other vertebrates, primates recognize their relatives, primarily to minimize inbreeding, but also to facilitate nepotism. Although associative, social learning is typically credited for discrimination of familiar kin, discrimination of unfamiliar kin remains unexplained. As sex-biased dispersal in long-lived species cannot consistently prevent encounters between unfamiliar kin, inbreeding remains a threat and mechanisms to avoid it beg explanation. Using a molecular approach that combined analyses of biochemical and microsatellite markers in 17 female and 19 male ring-tailed lemurs (Lemur catta, we describe odor-gene covariance to establish the feasibility of olfactory-mediated kin recognition. Results Despite derivation from different genital glands, labial and scrotal secretions shared about 170 of their respective 338 and 203 semiochemicals. In addition, these semiochemicals encoded information about genetic relatedness within and between the sexes. Although the sexes showed opposite seasonal patterns in signal complexity, the odor profiles of related individuals (whether same-sex or mixed-sex dyads converged most strongly in the competitive breeding season. Thus, a strong, mutual olfactory signal of genetic relatedness appeared specifically when such information would be crucial for preventing inbreeding. That weaker signals of genetic relatedness might exist year round could provide a mechanism to explain nepotism between unfamiliar kin. Conclusion We suggest that signal convergence between the sexes may reflect strong selective pressures on kin recognition, whereas signal convergence within the sexes may arise as its by-product or function independently to prevent competition between unfamiliar relatives. The link between an individual's genome and its olfactory signals could be mediated by biosynthetic pathways producing polymorphic semiochemicals or by carrier proteins modifying the individual bouquet of

  3. Sex steroids regulation of appetitive behavior.

    Science.gov (United States)

    Bautista, C J; Martínez-Samayoa, P M; Zambrano, E

    2012-10-01

    Appetite is the desire to satisfy the need to consume food, felt as hunger. It is regulated by the balance of food intake and energy expenditure via signals between the brain, the digestive tract and the adipose tissue. Males and females vary in terms of eating behavior as well as the way the body fat is stored. Energy balance and body fat distribution are part of the sexual dimorphism in many mammalian species including human beings. These sex dissimilarities could be related to the different sex steroid hormone profile in each sex. Gonadal steroid hormones play an important role in the regulation of food intake and energy homeostasis. Human epidemiological and experimental animal studies have shown that estradiol has a key role in the control of food intake and energy balance. Estradiol has long been known to inhibit feeding in animals. There are important changes in food intake patterns during the estrous cycle, with a reduction of food intake around the time of ovulation, when estradiol presents its highest levels. Men have less total fat and more central fat distribution which carries a much greater risk for metabolic disorders while women have more total fat and more gluteal/femoral subcutaneous fat distribution. Men and postmenopausal women accumulate more fat in the intraabdominal depot. This review is focused on the mechanism by which sex steroids affect feeding behavior and fat distribution.

  4. Fetal programming of appetite and obesity.

    Science.gov (United States)

    Breier, B H; Vickers, M H; Ikenasio, B A; Chan, K Y; Wong, W P

    2001-12-20

    Obesity and related metabolic disorders are prevalent health issues in modern society and are commonly attributed to lifestyle and dietary factors. However, the mechanisms by which environmental factors modulate the physiological systems that control weight regulation and the aetiology of metabolic disorders, which manifest in adult life, may have their roots before birth. The 'fetal origins' or 'fetal programming' paradigm is based on the observation that environmental changes can reset the developmental path during intrauterine development leading to obesity and cardiovascular and metabolic disorders later in life. The pathogenesis is not based on genetic defects but on altered genetic expression as a consequence of an adaptation to environmental changes during fetal development. While many endocrine systems can be affected by fetal programming recent experimental studies suggest that leptin and insulin resistance are critical endocrine defects in the pathogenesis of programming-induced obesity and metabolic disorders. However, it remains to be determined whether postnatal obesity is a consequence of programming of appetite regulation and whether hyperphagia is the main underlying cause of the increased adiposity and the development of metabolic disorders.

  5. Comparison between Olfactory Function of Pregnant Women and ...

    African Journals Online (AJOL)

    2017-05-22

    May 22, 2017 ... study was carried out to investigate and compare olfactory function of pregnant women with non-pregnant ..... Prevalence and assessment of qualitative olfactory dysfunction in different ... A qualitative and quantitative review.

  6. An Olfactory Indicator for Acid-Base Titrations.

    Science.gov (United States)

    Flair, Mark N.; Setzer, William N.

    1990-01-01

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

  7. Olfactory coding in the honeybee lateral horn.

    Science.gov (United States)

    Roussel, Edith; Carcaud, Julie; Combe, Maud; Giurfa, Martin; Sandoz, Jean-Christophe

    2014-03-03

    Olfactory systems dynamically encode odor information in the nervous system. Insects constitute a well-established model for the study of the neural processes underlying olfactory perception. In insects, odors are detected by sensory neurons located in the antennae, whose axons project to a primary processing center, the antennal lobe. There, the olfactory message is reshaped and further conveyed to higher-order centers, the mushroom bodies and the lateral horn. Previous work has intensively analyzed the principles of olfactory processing in the antennal lobe and in the mushroom bodies. However, how the lateral horn participates in olfactory coding remains comparatively more enigmatic. We studied odor representation at the input to the lateral horn of the honeybee, a social insect that relies on both floral odors for foraging and pheromones for social communication. Using in vivo calcium imaging, we show consistent neural activity in the honeybee lateral horn upon stimulation with both floral volatiles and social pheromones. Recordings reveal odor-specific maps in this brain region as stimulations with the same odorant elicit more similar spatial activity patterns than stimulations with different odorants. Odor-similarity relationships are mostly conserved between antennal lobe and lateral horn, so that odor maps recorded in the lateral horn allow predicting bees' behavioral responses to floral odorants. In addition, a clear segregation of odorants based on pheromone type is found in both structures. The lateral horn thus contains an odor-specific map with distinct representations for the different bee pheromones, a prerequisite for eliciting specific behaviors.

  8. Nonneoplastic changes in the olfactory epithelium--experimental studies.

    OpenAIRE

    Gaskell, B. A.

    1990-01-01

    Interest in the olfactory mucosa has increased in recent years, since it has been shown to possess a considerable amount of cytochrome P-450-dependent monooxygenase activity and a wide variety of chemicals have been identified as olfactory toxins. Many chemicals induce lesions of a general nature in the olfactory mucosa, i.e., inflammation, degeneration, regeneration, and proliferation, whereas others cause more specific effects. Changes in the olfactory mucosa with reference to chemicals tha...

  9. 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.

  10. Changes in the neural representation of odorants after olfactory deprivation in the adult mouse olfactory bulb.

    Science.gov (United States)

    Kass, Marley D; Pottackal, Joseph; Turkel, Daniel J; McGann, John P

    2013-01-01

    Olfactory sensory deprivation during development has been shown to induce significant alterations in the neurophysiology of olfactory receptor neurons (ORNs), the primary sensory inputs to the brain's olfactory bulb. Deprivation has also been shown to alter the neurochemistry of the adult olfactory system, but the physiological consequences of these changes are poorly understood. Here we used in vivo synaptopHluorin (spH) imaging to visualize odorant-evoked neurotransmitter release from ORNs in adult transgenic mice that underwent 4 weeks of unilateral olfactory deprivation. Deprivation reduced odorant-evoked spH signals compared with sham-occluded mice. Unexpectedly, this reduction was equivalent between ORNs on the open and plugged sides. Changes in odorant selectivity of glomerular subpopulations of ORNs were also observed, but only in ORNs on the open side of deprived mice. These results suggest that naris occlusion in adult mice produces substantial changes in primary olfactory processing which may reflect not only the decrease in olfactory stimulation on the occluded side but also the alteration of response properties on the intact side. We also observed a modest effect of true sham occlusions that included noseplug insertion and removal, suggesting that conventional noseplug techniques may have physiological effects independent of deprivation per se and thus require more careful controls than has been previously appreciated.

  11. Immediate extinction causes a less durable loss of performance than delayed extinction following either fear or appetitive conditioning

    OpenAIRE

    Woods, Amanda M.; Bouton, Mark E.

    2008-01-01

    Five experiments with rat subjects compared the effects of immediate and delayed extinction on the durability of extinction learning. Three experiments examined extinction of fear conditioning (using the conditioned emotional response method), and two experiments examined extinction of appetitive conditioning (using the food-cup entry method). In all experiments, conditioning and extinction were accomplished in single sessions, and retention testing took place 24 h after extinction. In both f...

  12. Olfactory bulbectomy, but not odor conditioned aversion, induces the differentiation of immature neurons in the adult rat piriform cortex.

    Science.gov (United States)

    Gómez-Climent, M Á; Hernández-González, S; Shionoya, K; Belles, M; Alonso-Llosa, G; Datiche, F; Nacher, J

    2011-05-05

    The piriform cortex layer II of young-adult rats presents a population of prenatally generated cells, which express immature neuronal markers, such as the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) or doublecortin (DCX), and display structural characteristics of immature neurons. The number of PSA-NCAM/DCX expressing cells in this region decreases markedly as age progresses, suggesting that these cells differentiate or die. Since the piriform cortex receives a major input from the olfactory bulb and participates in olfactory information processing, it is possible that the immature neurons in layer II are affected by manipulations of the olfactory bulb or olfactory learning. It is not known whether these cells can be induced to differentiate and, if so, what would be their fate. In order to address these questions, we have performed unilateral olfactory bulbectomy (OBX) and an olfactory learning paradigm (taste-potentiated odor aversion, TPOA), in young-adult rats and have studied the expression of different mature and immature neuronal markers, as well as the presence of cell death. We have found that 14 h after OBX there was a dramatic decrease in the number of both PSA-NCAM and DCX expressing cells in piriform cortex layer II, whereas that of cells expressing NeuN, a mature neuronal marker, increased. By contrast, the number of cells expressing glutamate decarboxylase, isoform 67 (GAD67), a marker for interneurons, decreased slightly. Additionally, we have not found evidence of numbers of dying cells high enough to justify the disappearance of immature neurons. Analysis of animals subjected to TPOA revealed that this paradigm does not affect PSA-NCAM expressing cells. Our results strongly suggest that OBX can induce the maturation of immature neurons in the piriform cortex layer II and that these cells do not become interneurons. By contrast, these cells do not seem to play a crucial role in olfactory memory.

  13. Does post-infectious olfactory loss affect mood more severely than chronic sinusitis with olfactory loss?

    Science.gov (United States)

    Jung, Yong G; Lee, Jun-Seok; Park, Gi C

    2014-11-01

    Olfactory deficits that develop after viral upper respiratory infection (URI) may have different effects on patient depression index compared to chronic sinusitis with olfactory loss. However, there have been no controlled trials to evaluate the different effects of chronic sinusitis and URI on depression index. Prospective study of 25 subjects in two groups. This study enrolled 25 participants who were diagnosed with post-URI olfactory loss as the study group and 25 patients with chronic sinusitis and olfactory loss as a control group. Control group participants were matched for age, sex, and degree of olfactory loss (threshold, discrimination, and identification [TDI]). We compared the Beck Depression Inventory (BDI) scores of each group and analyzed the correlation between TDI and BDI. The mean BDI score of the post-URI group was significantly higher than that of the control group (14.52 ± 6.59 vs. 9.32 ± 5.23; P=.002). Age, sex, and TDI score did not affect BDI score in the post-URI olfactory loss group. However, BDI score in the sinusitis group was inversely correlated with TDI score (R=-0.423; P=.035), and the BDI score of female subjects (11.00 ± 5.13) was significantly higher than that of male subjects (5.00 ± 2.16; P = .047). Post-URI olfactory loss affected patient mood more severely than chronic sinusitis with a similar degree of olfactory loss. This influence was not affected by sex, age, or TDI score in the post-URI olfactory loss group. 3b. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Olfactory comfort awareness (OCA). A new unit?

    Energy Technology Data Exchange (ETDEWEB)

    Kempski, D. von [DVK air vitalizing system, Duesseldorf (Germany)

    2005-07-01

    It is generally known that the perceived air quality has a great impact on the well-being of room occupants. Engineers tend to rely completely on measuring the absence of pollutants aiming for objectively clean air, but neglect the subjective awareness of room occupants or how they perceive indoor air quality. Neurophysiological and psychological research has shown that the hedonic value often plays the key role in determining that perception. It has to be understood that not only thermal conditions but also the sense of olfaction play major roles. This lack of awareness of the interactions between thermal and olfactory conditions frequently accounts for the dissatisfaction rate. This paper will concentrate on demonstrating the influence of the hedonic value on room occupants and on how to achieve air that from an olfactory perspective is perceived to be natural. This is different from the commonly known, perceived ''artificial'' air. Furthermore, it will show how important it is to evaluate healthy buildings not only for the absence of negative odors as expressed by the olf and decipol units. Olfactory comfort goes far beyond this scale and, therefore, it is necessary to introduce a new unit called olfactory comfort awareness OCA. OCA is a score between -10 and 10 that expresses the grade of olfactory comfort the room occupants perceive. This measure does not replace the well-accepted decipol unit but complements it, emphasising the importance not only of the absence of negative influencing odorants, but also the importance of olfactory comfort as measurement by the new unit. (Orig.)

  15. Higher Eating Frequency Does Not Decrease Appetite in Healthy Adults.

    Science.gov (United States)

    Perrigue, Martine M; Drewnowski, Adam; Wang, Ching-Yun; Neuhouser, Marian L

    2016-01-01

    Consumption of small, frequent meals is suggested as an effective approach to control appetite and food intake and might be a strategy for weight loss or healthy weight maintenance. Despite much speculation on the topic, scientific evidence is limited to support such a relation in the absence of changes to diet composition. We examined the effects of high compared with low eating frequency (EF) on self-reported appetite as a secondary outcome in a controlled trial. We conducted a randomized, crossover intervention trial in 12 participants (4 men, 8 women) who completed 2 isocaloric 3-wk intervention phases of low EF (3 eating occasions/d) compared with high EF (8 eating occasions/d). On the last morning of each study phase, participants completed a 4-h appetite testing session. During the appetite testing session, participants completing the low EF phase consumed a meal at 0800. Participants completing the high EF intervention consumed the same meal spread evenly over 2 eating occasions at 0800 and 1030. Standardized ratings of hunger, desire to eat, fullness, thirst, and nausea were completed every 30 min with the use of paper-and-pencil semianchored 100-mm visual analog scales. A composite appetite score was calculated as the mean of hunger, desire to eat, and the inverse of fullness (calculated as 100-fullness rating). Linear regression analysis compared ratings between low EF and high EF conditions. The mean composite appetite score was higher in the high EF condition for the total testing period (baseline through 1200) (P healthy adults do not support the popularized notion that small, frequent meals help to decrease overall appetite. This trial was registered at clinicaltrials.gov as NCT02548026. © 2016 American Society for Nutrition.

  16. Interneurons in the human olfactory system in Alzheimer's disease.

    Science.gov (United States)

    Saiz-Sanchez, Daniel; Flores-Cuadrado, Alicia; Ubeda-Bañon, Isabel; de la Rosa-Prieto, Carlos; Martinez-Marcos, Alino

    2016-02-01

    The principal olfactory structures display Alzheimer's disease (AD) related pathology at early stages of the disease. Consequently, olfactory deficits are among the earliest symptoms. Reliable olfactory tests for accurate clinical diagnosis are rarely made. In addition, neuropathological analysis postmortem of olfactory structures is often not made. Therefore, the relationship between the clinical features and the underlying pathology is poorly defined. Traditionally, research into Alzheimer's disease has focused on the degeneration of cortical temporal projection neurons and cholinergic neurons. Recent evidence has demonstrated the neurodegeneration of interneuron populations in AD. This review provides an updated overview of the pathological involvement of interneuron populations in the human olfactory system in Alzheimer's disease.

  17. The importance of the olfactory sense in the human behavior and evolution.

    Science.gov (United States)

    Sarafoleanu, C; Mella, C; Georgescu, M; Perederco, C

    2009-01-01

    Not long ago it was believed that the human olfactory sense had a low importance, a vision which turned into the exploration of the environment. Recent studies have shown that, despite the weak representation of the olfactory receptor common in other species too, the cortical areas of integration of the olfactory sensations are very large and have important interconnections with memory, language, and neuro-vegetative areas. In humans, olfaction has a small contribution in identifying objects or other people, but plays an important social and emotional part. People learn to love or to hate certain foods or objects only by appreciating their odor and this proved to be a very important economic factor. The most significant role of olfactory signals in humans appears to be the modulation of their behavior and interpersonal relationships, of their affiliation to certain groups or social classes, having a major influence in their tastes and personality. signal that will be sent to the specialized areas in their tastes and personality.

  18. Appetite suppression based on selective inhibition of NPY receptors.

    Science.gov (United States)

    Chamorro, S; Della-Zuana, O; Fauchère, J-L; Félétou, M; Galizzi, J-P; Levens, N

    2002-03-01

    The aim of this review is to critically assess available evidence that blockade of the actions of NPY at one of the five NPY receptor subtypes represents an attractive new drug discovery target for the development of an appetite suppressant drug. Blockade of the central actions of NPY using anti-NPY antibodies, antisense oligodeoxynucleotides against NPY and NPY receptor antagonists results in a decrease in food intake in energy-deprived animals. These results appear to show that endogenous NPY plays a role in the control of appetite. The fact that NPY receptors exist as at least five different subtypes raises the possibility that the actions of endogenous NPY on food intake can be adequately dissociated from other effects of the peptide. Current drug discovery has produced a number of highly selective NPY receptor antagonists which have been used to establish the NPY Y(1) receptor subtype as the most critical in regulating short-term food intake. However, additional studies are now needed to more clearly define the relative contribution of NPY acting through the NPY Y2 and NPY Y5 receptors in the complex sequence of physiological and behavioral events that underlie the long-term control of appetite. Blockade of the NPY receptor may produce appetite-suppressing drugs. However, it is too early to state with certainty whether a single subtype selective drug used alone or a combination of NPY receptor selective antagonists used in combination will be necessary to adequately influence appetite regulation.

  19. Role of the serotoninergic system in the sodium appetite control.

    Science.gov (United States)

    Reis, Luís C

    2007-06-01

    The present article reviews the role of the serotoninergic system in the regulation of the sodium appetite. Data from the peripheral and icv administration of serotoninergic (5-HTergic) agents showed the participation of 5-HT2/3 receptors in the modulation of sodium appetite. These observations were extended with the studies carried out after brain serotonin depletion, lesions of DRN and during blockade of 5-HT2A/2C receptors in lateral parabrachial nucleus (LPBN). Brain serotonin depletion and lesions of DRN increased the sodium appetite response, in basal conditions, after sodium depletion and hypovolemia or after beta-adrenergic stimulation as well. These observations raised the hypothesis that the suppression of ascending pathways from the DRN, possibly, 5-HTergic fibers, modifies the angiotensinergic or sodium sensing mechanisms of the subfornical organ involved in the control of the sodium appetite. 5-HTergic blockade in LPBN induced to similar results, particularly those regarded to the natriorexigenic response evoked by volume depletion or increase of the hypertonic saline ingestion induced by brain angiotensinergic stimulation. In conclusion, many evidences lead to acceptation of an integrated participation resulting of an interaction, between DRN and LPBN, for the sodium appetite control.

  20. Appetite awareness as a mediator in an eating disorders prevention program.

    Science.gov (United States)

    Brown, Amanda Joelle; Smith, Lucy T; Craighead, Linda W

    2010-01-01

    Difficulties identifying appetite signals and emotions have been implicated in the development and maintenance of disordered eating. The current study evaluated the mediating roles of appetite awareness and emotional awareness in a brief eating disorders prevention program designed to help participants identify and respond to internal appetite signals. A series of regression analyses was carried out to test the mediator effects of appetite and emotional awareness. Appetite awareness, but not emotional awareness, mediated improvements in binge eating symptoms as well as eating- and weight-control self-efficacy. Appetite awareness appears to be an effective target for eating disorders prevention programs.

  1. Shh-proteoglycan interactions regulate maturation of olfactory glomerular circuitry.

    Science.gov (United States)

    Persson, Laura; Witt, Rochelle M; Galligan, Meghan; Greer, Paul L; Eisner, Adriana; Pazyra-Murphy, Maria F; Datta, Sandeep R; Segal, Rosalind A

    2014-12-01

    The olfactory system relies on precise circuitry connecting olfactory sensory neurons (OSNs) and appropriate relay and processing neurons of the olfactory bulb (OB). In mammals, the exact correspondence between specific olfactory receptor types and individual glomeruli enables a spatially precise map of glomerular activation that corresponds to distinct odors. However, the mechanisms that govern the establishment and maintenance of the glomerular circuitry are largely unknown. Here we show that high levels of Sonic Hedgehog (Shh) signaling at multiple sites enable refinement and maintenance of olfactory glomerular circuitry. Mice expressing a mutant version of Shh (Shh(Ala/Ala)), with impaired binding to proteoglycan co-receptors, exhibit disproportionately small olfactory bulbs containing fewer glomeruli. Notably, in mutant animals the correspondence between individual glomeruli and specific olfactory receptors is lost, as olfactory sensory neurons expressing different olfactory receptors converge on the same glomeruli. These deficits arise at late stages in post-natal development and continue into adulthood, indicating impaired pruning of erroneous connections within the olfactory bulb. In addition, mature Shh(Ala/Ala) mice exhibit decreased proliferation in the subventricular zone (SVZ), with particular reduction in neurogenesis of calbindin-expressing periglomerular cells. Thus, Shh interactions with proteoglycan co-receptors function at multiple locations to regulate neurogenesis and precise olfactory connectivity, thereby promoting functional neuronal circuitry.

  2. Subjective and objective olfactory abnormalities in Crohn's disease.

    Science.gov (United States)

    Fischer, Marie; Zopf, Yurdagül; Elm, Cornelia; Pechmann, Georg; Hahn, Eckhart G; Schwab, Dieter; Kornhuber, Johannes; Thuerauf, Norbert Joachim

    2014-07-01

    The pathogenesis of Crohn's disease (CD) is still unknown, but the involvement of the olfactory system in CD appears possible. No study to date has systematically assessed the olfactory function in CD patients. We investigated the olfactory function in CD patients in active (n = 31) and inactive disease (n = 27) and in a control group of age- and sex-matched healthy subjects (n = 35). Subjective olfactory testing was applied using the Sniffin' Sticks test. For olfactory testing, olfactory event-related potentials (OERPs) were obtained with a 4-channel olfactometer using phenyl ethyl alcohol (PEA) and hydrogen sulfide (H(2)S). Carbon dioxide (CO(2)) was employed as control stimulus, and chemosomatosensory event-related potentials (CSSERPs) were registered. Results of the Sniffin' Sticks test revealed significantly different olfactory hedonic judgment with increased olfactory hedonic estimates for pleasant odorants in CD patients in active disease compared with healthy subjects. A statistical trend was found toward lower olfactory thresholds in CD patients. In objective olfactory testing, CD patients showed lower amplitudes of OERPs and CSSERPs. Additionally, OERPs showed significantly shorter N1- and P2 latencies following stimulation of the right nostril with H(2)S in CD patients in inactive disease compared with controls. Our study demonstrates specific abnormalities of olfactory perception in CD patients.

  3. Sphenoid esthesioneuroblastoma arising from the hindmost olfactory filament.

    Science.gov (United States)

    Matsunaga, Mami; Nakagawa, Takayuki; Sakamoto, Tatsunori; Ito, Juichi

    2015-04-01

    Esthesioneuroblastoma (ENB), or olfactory neuroblastoma, is a rare malignant neoplasm arising from the olfactory neuroepithelium. Typically, ENBs are found in the olfactory cleft with extension to the ethmoid sinuses or anterior skull base. Here we report a case of ENB located in the sphenoid sinus, which had been considered as an ectopic ENB. However, endoscopic resection revealed the continuity of the tumor with the hindmost olfactory filament. The present case suggests that an ENB in the sphenoid sinus was not ectopic, but arose from the normal olfactory neuroepithelium. This continuity of the ENB with this filament indicated that the tumor was not ectopic, and that there was possible tumor invasion into the olfactory neuroepithelium in the cribriform niche. Therefore, pathological examination of the olfactory neuroepithelium in the cribriform niche may be necessary in case of sphenoid ENBs.

  4. The diversified function and potential therapy of ectopic olfactory receptors in non-olfactory tissues.

    Science.gov (United States)

    Chen, Zhe; Zhao, Hong; Fu, Nian; Chen, Linxi

    2017-03-24

    Olfactory receptors (ORs) are mainly distributed in olfactory neurons and play a key role in detecting volatile odorants, eventually resulting in the production of smell perception. Recently, it is also reported that ORs are expressed in non-olfactory tissues including heart, lung, sperm, skin, and cancerous tissues. Interestingly, ectopic ORs are associated with the development of diseases in non-olfactory tissues. For instance, ectopic ORs initiate the hypoxic ventilatory responses and maintain the oxygen homeostasis of breathing in the carotid body when oxygen levels decline. Ectopic ORs induce glucose homeostasis in diabetes. Ectopic ORs regulate systemic blood pressure by increasing renin secretion and vasodilation. Ectopic ORs participate in the process of tumor cell proliferation, apoptosis, metastasis, and invasiveness. Ectopic ORs accelerate the occurrence of obesity, angiogenesis and wound-healing processes. Ectopic ORs affect fetal hemoglobin levels in sickle cell anemia and thalassemia. Finally, we also elaborate some ligands targeting for ORs. Obviously, the diversified function and related signal pathway of ectopic ORs may play a potential therapeutic target in non-olfactory tissues. Thus, this review focuses on the latest research results about the diversified function and therapeutic potential of ectopic ORs in non-olfactory tissues. © 2017 Wiley Periodicals, Inc.

  5. Encoding olfactory signals via multiple chemosensory systems.

    Science.gov (United States)

    Ma, Minghong

    2007-01-01

    Most animals have evolved multiple olfactory systems to detect general odors as well as social cues. The sophistication and interaction of these systems permit precise detection of food, danger, and mates, all crucial elements for survival. In most mammals, the nose contains two well described chemosensory apparatuses (the main olfactory epithelium and the vomeronasal organ), each of which comprises several subtypes of sensory neurons expressing distinct receptors and signal transduction machineries. In many species (e.g., rodents), the nasal cavity also includes two spatially segregated clusters of neurons forming the septal organ of Masera and the Grueneberg ganglion. Results of recent studies suggest that these chemosensory systems perceive diverse but overlapping olfactory cues and that some neurons may even detect the pressure changes carried by the airflow. This review provides an update on how chemosensory neurons transduce chemical (and possibly mechanical) stimuli into electrical signals, and what information each system brings into the brain. Future investigation will focus on the specific ligands that each system detects with a behavioral context and the processing networks that each system involves in the brain. Such studies will lead to a better understanding of how the multiple olfactory systems, acting in concert, offer a complete representation of the chemical world.

  6. 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.

  7. 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.

  8. 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...

  9. Olfactory alterations in patients with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Sergio Semeraro Jordy

    Full Text Available ABSTRACT This cross-sectional study involves 100 multiple sclerosis (MS and 100 non-MS patients, under the age of 60 years old, with nasal obstruction, traumatic brain injury, previous rhinoplasty or neurosurgery, and so forth. Objective To assess olfactory function using the Connecticut test and verify correlations between olfactory alteration, disease duration and the Expanded Disability Status Scale (EDSS. Methods One hundred MS patients and 100 healthy control patients responded to a questionnaire. Those with olfactory alteration underwent a facial CT to exclude other causes. Results Thirty-two percent of patients showed alterations, compared with 3% in the healthy control group. Patients having EDSS above 4, showed a 5.2-times increased risk of dysfunction. Patients over 38 years of age have a 2.2-times increased risk over younger patients. Conclusions Because MS patients are likely to experience olfactory alterations, this study is a useful tool in follow-up care, although more studies are necessary to evaluate the correlations in MS evolution.

  10. The value of identity: olfactory notes on orbitofrontal cortex function.

    Science.gov (United States)

    Gottfried, Jay A; Zelano, Christina

    2011-12-01

    Neuroscientific research has emphatically promoted the idea that the key function of the orbitofrontal cortex (OFC) is to encode value. Associative learning studies indicate that OFC representations of stimulus cues reflect the predictive value of expected outcomes. Neuroeconomic studies suggest that the OFC distills abstract representations of value from discrete commodities to optimize choice. Although value-based models provide good explanatory power for many different findings, these models are typically disconnected from the very stimuli and commodities giving rise to those value representations. Little provision is made, either theoretically or empirically, for the necessary cooperative role of object identity, without which value becomes orphaned from its source. As a step toward remediating the value of identity, this review provides a focused olfactory survey of OFC research, including new work from our lab, to highlight the elemental involvement of this region in stimulus-specific predictive coding of both perceptual outcomes and expected values.

  11. Harmful effects of cadmium on olfactory system in mice.

    Science.gov (United States)

    Bondier, Jean-Robert; Michel, Germaine; Propper, Alain; Badot, Pierre-Marie

    2008-10-01

    The inhalation of certain metals can result in olfactory epithelial injury, an altered sense of smell, and direct delivery of the metal from the olfactory epithelium to the olfactory bulbs and other parts of the central nervous system. The purpose of this study was to examine whether mice given an intranasal instillation of cadmium would develop altered olfactory function and to assess whether cadmium may be transported directly from the olfactory epithelium to the central nervous system. To evaluate cadmium's ability to induce anosmia and on the basis of olfactory epithelium sensitivity to metals, the aim of this study was first to study cadmium effects on the olfactory function and secondly to check whether cadmium may be transported from the nasal area to the central nervous system. After an intranasal instillation of a solution containing CdCl2 at 136 mM, we observed in treated mice: (1) a partial destruction of the olfactory epithelium, which is reduced to three or four basal cell layers followed by a progressive regeneration; (2) a loss of odor discrimination with a subsequent recovery; and (3) a cadmium uptake by olfactory bulbs demonstrated using atomic absorption spectrophotometry, but not by other parts of the central nervous system. Cadmium was delivered to the olfactory bulbs, most likely along the olfactory nerve, thereby bypassing the intact blood-brain barrier. We consider that cadmium can penetrate olfactory epithelium and hence be transported to olfactory bulbs. The olfactory route could therefore be a likely way to reach the brain and should be taken into account for occupational risk assessments for this metal.

  12. Long-term health benefits of appetite suppressants remain unproven

    Directory of Open Access Journals (Sweden)

    Francisco José Roma Paumgartten

    2011-12-01

    Full Text Available Because of the increasing prevalence of obesity, prevention and treatment of overweight has become a major public health concern. In addition to diet and exercise, drugs are needed for patients who failed to lose weight with behavioral treatment. The current article aimed to summarize recent concerns on the safety and efficacy of appetite suppressants. Several appetite suppressants have been banned for safety reasons. In 2010, sibutramine was withdrawn from the market because a long-term study showed it increased the risks of cardiovascular events. So far no study with a sufficiently large sample size has demonstrated that appetite suppressants can reduce morbidity and mortality associated with overweight. The withdrawal of sibutramine highlights that guidelines for the evaluation of weight control drugs must be more stringent, and studies on their long-term health benefits are needed prior to their marketing.

  13. Early growth and postprandial appetite regulatory hormone responses

    DEFF Research Database (Denmark)

    Perälä, Mia-Maria; Kajantie, Eero; Valsta, Liisa M

    2013-01-01

    Strong epidemiological evidence suggests that slow prenatal or postnatal growth is associated with an increased risk of CVD and other metabolic diseases. However, little is known whether early growth affects postprandial metabolism and, especially, the appetite regulatory hormone system. Therefore......, we investigated the impact of early growth on postprandial appetite regulatory hormone responses to two high-protein and two high-fat content meals. Healthy, 65-75-year-old volunteers from the Helsinki Birth Cohort Study were recruited; twelve with a slow increase in BMI during the first year of life......, early growth may have a role in programming appetite regulatory hormone secretion in later life. Slow early growth is also associated with higher postprandial insulin and TAG responses but not with incretin levels....

  14. Appetitive aggression as a resilience factor against trauma disorders: appetitive aggression and PTSD in German World War II veterans.

    Science.gov (United States)

    Weierstall, Roland; Huth, Sina; Knecht, Jasmin; Nandi, Corina; Elbert, Thomas

    2012-01-01

    Repeated exposure to traumatic stressors such as combat results in chronic symptoms of PTSD. However, previous findings suggest that former soldiers who report combat-related aggression to be appetitive are more resilient to develop PTSD. Appetitive Aggression should therefore prevent widespread mental suffering in perpetrators of severe atrocities even after decades. To test the long-term relationship between trauma-related illness and attraction to aggression, we surveyed a sample of 51 German male World-War II veterans (age: M = 86.7, SD = 2.8). War-related appetitive aggression was assessed with the Appetitive Aggression Scale (AAS). Current- and lifetime PTSD symptoms were assessed with the PSS-I. In a linear regression analysis accounting for 31% of the variance we found that veterans that score higher on the AAS show lower PSS-I symptom severity scores across their whole post-war lifetime (β = - .31, p = .014). The effect size and power were sufficient (f(2) = 0.51, (1-β) = .99). The same was true for current PTSD (β = - .27, p = .030). Appetitive Aggression appears to be a resilience factor for negative long-term effects of combat experiences in perpetrators of violence. This result has practical relevance for preventing trauma-related mental suffering in Peace Corps and for designing adequate homecoming reception for veterans.

  15. Appetitive aggression as a resilience factor against trauma disorders: appetitive aggression and PTSD in German World War II veterans.

    Directory of Open Access Journals (Sweden)

    Roland Weierstall

    Full Text Available BACKGROUND: Repeated exposure to traumatic stressors such as combat results in chronic symptoms of PTSD. However, previous findings suggest that former soldiers who report combat-related aggression to be appetitive are more resilient to develop PTSD. Appetitive Aggression should therefore prevent widespread mental suffering in perpetrators of severe atrocities even after decades. METHODS AND FINDINGS: To test the long-term relationship between trauma-related illness and attraction to aggression, we surveyed a sample of 51 German male World-War II veterans (age: M = 86.7, SD = 2.8. War-related appetitive aggression was assessed with the Appetitive Aggression Scale (AAS. Current- and lifetime PTSD symptoms were assessed with the PSS-I. In a linear regression analysis accounting for 31% of the variance we found that veterans that score higher on the AAS show lower PSS-I symptom severity scores across their whole post-war lifetime (β = - .31, p = .014. The effect size and power were sufficient (f(2 = 0.51, (1-β = .99. The same was true for current PTSD (β = - .27, p = .030. CONCLUSIONS: Appetitive Aggression appears to be a resilience factor for negative long-term effects of combat experiences in perpetrators of violence. This result has practical relevance for preventing trauma-related mental suffering in Peace Corps and for designing adequate homecoming reception for veterans.

  16. Appetite and falls: Old age and lived experiences

    Directory of Open Access Journals (Sweden)

    Marianne Mahler

    2012-02-01

    Full Text Available Falling among older adults is a well-known public health problem but the association between falling and appetite is seldom studied although poor nutritional status is accepted as a risk factor for falls. On this background the aim of this study was to understand how older adults, who have fallen several times within a year, related their experiences of appetite as a phenomenon in everyday life. In narrative in-depth interviews, eight women and four men contributed with their stories. Using interpretative phenomenology the thematic analysis resulted in three main themes: appetite for food; appetite for social relations and appetite for influence. Eating was not trivial everyday routine and required self-regimentation. Meals were not an object of desire, but of discipline out of the wish to survive. Feelings, reflections and ambivalence were bound to the lack of appetite on food. The participants were oriented towards the forbidden, the delicious and to everyday food as a strengthener and as medicine. In their dependency on help, home was the framework for establishing social relations as means of social support. As well as family and neighbours, the significant others were persons on whom the participants were dependent. Personal relationships and mutual dependencies may ensure social security in lives characterised by contingency and maintain influence in daily life. Falling is both a dramatic and a trivial incident where life and death could be at stake. From this perspective, connectedness was prominent in all fall stories. The quest for influence and a sense of social connectedness was the incentive to re-enter local community arenas and to express solidarity. In health-care practice multi-factorial fall-prevention should be complemented with a multi-dimensional approach in order to balance the medical approach with humanistic and societal approaches towards fall-prevention.

  17. Specific appetite for carotenoids in a colorful bird.

    Directory of Open Access Journals (Sweden)

    Juan Carlos Senar

    Full Text Available BACKGROUND: Since carotenoids have physiological functions necessary for maintaining health, individuals should be selected to actively seek and develop a specific appetite for these compounds. METHODOLOGY/PRINCIPAL FINDINGS: Great tits Parus major in a diet choice experiment, both in captivity and the field, preferred carotenoid-enriched diets to control diets. The food items did not differ in any other aspects measured besides carotenoid content. CONCLUSIONS/SIGNIFICANCE: Specific appetite for carotenoids is here demonstrated for the first time, placing these compounds on a par with essential nutrients as sodium or calcium.

  18. A unique method for the isolation of nasal olfactory stem cells in living rats.

    Science.gov (United States)

    Stamegna, Jean-Claude; Girard, Stéphane D; Veron, Antoine; Sicard, Gilles; Khrestchatisky, Michel; Feron, François; Roman, François S

    2014-05-01

    Stem cells are attractive tools to develop new therapeutic strategies for a variety of disorders. While ethical and technical issues, associated with embryonic, fetal and neural stem cells, limit the translation to clinical applications, the nasal stem cells identified in the human olfactory mucosa stand as a promising candidate for stem cell-based therapies. Located in the back of the nose, this multipotent stem cell type is readily accessible in humans, a feature that makes these cells highly suitable for the development of autologous cell-based therapies. However, preclinical studies based on autologous transplantation of rodent olfactory stem cells are impeded because of the narrow opening of the nasal cavity. In this study, we report the development of a unique method permitting to quickly and safely biopsy olfactory mucosa in rats. Using this newly developed technique, rat stem cells expressing the stem cell marker Nestin were successfully isolated without requiring the sacrifice of the donor animal. As an evidence of the self-renewal capacity of the isolated cells, several millions of rat cells were amplified from a single biopsy within four weeks. Using an olfactory discrimination test, we additionally showed that this novel biopsy method does not affect the sense of smell and the learning and memory abilities of the operated animals. This study describes for the first time a methodology allowing the derivation of rat nasal cells in a way that is suitable for studying the effects of autologous transplantation of any cell type present in the olfactory mucosa in a wide variety of rat models.

  19. Neuropeptide Regulation of Appetite and Reproduction

    Directory of Open Access Journals (Sweden)

    Small CJ

    2004-01-01

    Full Text Available It is now recognised that appropriate regulation of reproduction, energy intake and energy expenditure, and thus maintenance of body weight and fertility, relies on complex hypothalamic neuro-circuitry. Feeding and reproductive function are closely linked. During times of under nourishment and falling body fat the reproductive axis is down regulated. Circulating factors and hypothalamic circuits co-ordinate these responses. Leptin has been described to be an important peripheral signal that indicates body fat stores to the hypothalamus and thus links nutrition and reproduction. Leptin acts by altering neuropeptide circuits in the hypothalamus, which alter gonadotrophin releasing hormone (GnRH release and food intake. The importance of key neuropeptide systems identified in rodents is now being established in man. Notably mutations in the melanocortin MC4 receptor are found in up to 4 % of the morbidly obese whilst in a proportion of patients with anorexia nervosa mutations have been identified in the agoutirelated peptide (AgRP gene, which codes for an endogenous antagonist of this receptor. Intranasal administration of a melanocortin fragment known to activate the MC4 receptor decreases adiposity in humans. The melanocortin system has been shown to influence the reproductive axis in rodents. However, the role of the melanocortin system in the control of reproduction in humans remains to be established. Since the discovery of leptin, attention has also been focused on peripheral signals that regulate reproduction, food intake and energy expenditure, either directly or via feedback on hypothalamic circuits. Notable new discoveries in this area include the gastric hormone ghrelin. Circulating ghrelin stimulates food intake in rodents and humans although an influence on the reproductive axis is yet to be reported. Neuropeptidregulation von Appetit und Reproduktion. Mittlerweile gilt es als anerkannt, daß eine entsprechende Regulation der

  20. Local neurons play key roles in the mammalian olfactory bulb.

    Science.gov (United States)

    Saghatelyan, Armen; Carleton, Alan; Lagier, Samuel; de Chevigny, Antoine; Lledo, Pierre-Marie

    2003-01-01

    Over the past few decades, research exploring how the brain perceives, discriminates, and recognizes odorant molecules has received a growing interest. Today, olfaction is no longer considered a matter of poetry. Chemical senses entered the biological era when an increasing number of scientists started to elucidate the early stages of the olfactory pathway. A combination of genetic, biochemical, cellular, electrophysiological and behavioral methods has provided a picture of how odor information is processed in the olfactory system as it moves from the periphery to higher areas of the brain. Our group is exploring the physiology of the main olfactory bulb, the first processing relay in the mammalian brain. From different electrophysiological approaches, we are attempting to understand the cellular rules that contribute to the synaptic transmission and plasticity at this central relay. How olfactory sensory inputs, originating from the olfactory epithelium located in the nasal cavity, are encoded in the main olfactory bulb remains a crucial question for understanding odor processing. More importantly, the persistence of a high level of neurogenesis continuously supplying the adult olfactory bulb with newborn local neurons provides an attractive model to investigate how basic olfactory functions are maintained when a large proportion of local neurons are continuously renewed. For this purpose, we summarize the current ideas concerning the molecular mechanisms and organizational strategies used by the olfactory system to encode and process information in the main olfactory bulb. We discuss the degree of sensitivity of the bulbar neuronal network activity to the persistence of this high level of neurogenesis that is modulated by sensory experience. Finally, it is worth mentioning that analyzing the molecular mechanisms and organizational strategies used by the olfactory system to transduce, encode, and process odorant information in the olfactory bulb should aid in

  1. Anatomical specializations for enhanced olfactory sensitivity in kiwi, Apteryx mantelli.

    Science.gov (United States)

    Corfield, Jeremy R; Eisthen, Heather L; Iwaniuk, Andrew N; Parsons, Stuart

    2014-01-01

    The ability to function in a nocturnal and ground-dwelling niche requires a unique set of sensory specializations. The New Zealand kiwi has shifted away from vision, instead relying on auditory and tactile stimuli to function in its environment and locate prey. Behavioral evidence suggests that kiwi also rely on their sense of smell, using olfactory cues in foraging and possibly also in communication and social interactions. Anatomical studies appear to support these observations: the olfactory bulbs and tubercles have been suggested to be large in the kiwi relative to other birds, although the extent of this enlargement is poorly understood. In this study, we examine the size of the olfactory bulbs in kiwi and compare them with 55 other bird species, including emus, ostriches, rheas, tinamous, and 2 extinct species of moa (Dinornithiformes). We also examine the cytoarchitecture of the olfactory bulbs and olfactory epithelium to determine if any neural specializations beyond size are present that would increase olfactory acuity. Kiwi were a clear outlier in our analysis, with olfactory bulbs that are proportionately larger than those of any other bird in this study. Emus, close relatives of the kiwi, also had a relative enlargement of the olfactory bulbs, possibly supporting a phylogenetic link to well-developed olfaction. The olfactory bulbs in kiwi are almost in direct contact with the olfactory epithelium, which is indeed well developed and complex, with olfactory receptor cells occupying a large percentage of the epithelium. The anatomy of the kiwi olfactory system supports an enhancement for olfactory sensitivities, which is undoubtedly associated with their unique nocturnal niche.

  2. Prevalence and associated factors for decreased appetite among patients with stable heart failure

    OpenAIRE

    Andreae, Christina; Strömberg, Anna; Årestedt, Kristofer

    2016-01-01

    Aims and objectivesTo explore the prevalence of decreased appetite and factors associated with appetite among patients with stable heart failure. BackgroundDecreased appetite is an important factor for the development of undernutrition among patients with heart failure, but there are knowledge gaps about prevalence and the factors related to appetite in this patient group. DesignObservational, cross-sectional study. MethodsA total of 186 patients with mild to severe heart failure were consecu...

  3. Are Increased Weight and Appetite Useful Indicators of Depression in Children and Adolescents?

    OpenAIRE

    Cole, David A.; Cho, Sun-Joo; Martin, Nina C.; Youngstrom, Eric A.; March, John S.; Findling, Robert L.; Compas, Bruce E.; Goodyer, Ian M.; Rohde, Paul; Weissman, Myrna; Marilyn J. Essex; Hyde, Janet S.; Curry, John F.; Forehand, Rex; Marcia J. Slattery

    2012-01-01

    During childhood and adolescence, physiological, psychological, and behavioral processes strongly promote weight gain and increased appetite while also inhibiting weight loss and decreased appetite. The Diagnostic and Statistical Manual-IV (DSM–IV) treats both weight-gain/increased-appetite and weight-loss/decreased-appetite as symptoms of major depression during these developmental periods, despite the fact that one complements typical development and the other opposes it. To disentangle the...

  4. Nonhomeostatic control of human appetite and physical activity in regulation of energy balance.

    Science.gov (United States)

    Borer, Katarina T

    2010-07-01

    Ghrelin and leptin, putative controllers of human appetite, have no effect on human meal-to-meal appetite but respond to variations in energy availability. Nonhomeostatic characteristics of appetite and spontaneous activity stem from inhibition by leptin and ghrelin of brain reward circuit that is responsive to energy deficit, but refractory in obesity, and from the operation of a meal-timing circadian clock.

  5. An Appetitive Conditioned Stimulus Enhances Fear Acquisition and Impairs Fear Extinction

    Science.gov (United States)

    Leung, Hiu T.; Holmes, Nathan M.; Westbrook, R. Frederick

    2016-01-01

    Four experiments used between- and within-subject designs to examine appetitive-aversive interactions in rats. Experiments 1 and 2 examined the effect of an excitatory appetitive conditioned stimulus (CS) on acquisition and extinction of conditioned fear. In Experiment 1, a CS shocked in a compound with an appetitive excitor (i.e., a stimulus…

  6. Sensitive period for developing a robust trait of appetitive aggression

    Directory of Open Access Journals (Sweden)

    Anke eKöbach

    2015-10-01

    Full Text Available Violent behaviour can be intrinsically rewarding; especially combatants fighting in current civil wars present with elevated traits of appetitive aggression. The majority of these fighters were recruited as children or adolescents. In the present study we test whether there is a developmental period where combatants are sensitive for developing a robust trait of appetitive aggression.We investigated 95 combatants in their demobilization process that were recruited at different ages in the Kivu regions of the eastern Democratic Republic of Congo. Using random forest with conditional inference trees, we identified recruitment at the ages from 16 and 17 years as being predictive of the level of appetitive aggression; the number of lifetime, perpetrated acts was the most important predictor. We conclude that high levels of appetitive aggression develop in ex-combatants, especially in those recruited during their middle to late teenage, which is a developmental period marked by a natural inclination to exercise physical force. Consequently, ex-combatants may remain vulnerable for aggressive behaviour patterns and re-recruitment unless they are provided alternative strategies for dealing with their aggression.

  7. What and How You See Affects Your Appetite

    Directory of Open Access Journals (Sweden)

    Hsin-I Liao

    2011-10-01

    Full Text Available We have previously shown that priming by a given color facilitates participant's appetite to that color (Liao, et al., 2010. The current study aims to further examine whether the way participant's experiencing the color affects the effect of color on appetite. In two experiments, participants were primed with a particular color by conducting an active cognitive task, or with a color paper upon which the questionnaire was printed. Participants were asked to complete the questionnaire regarding the sensations of taste/smell/flavor and their consumptive attitude toward sample candies with different colors. We measured their actual initial choice of the colored candy when they answered the questionnaire and the total amount of candy consumption during the experiment. Results showed that active color priming by the pre-executed cognitive task was correlated with initial choice but not explicit attitude. By contrast, no such direct influence of color on appetite was found when the color was primed passively with the printed paper. We conclude that color priming can affect appetite even without conscious evaluation of the relationship between them and this is more so with active priming than passive priming.

  8. An Emerging Technology Framework for the Neurobiology of Appetite.

    Science.gov (United States)

    Sternson, Scott M; Atasoy, Deniz; Betley, J Nicholas; Henry, Fredrick E; Xu, Shengjin

    2016-02-09

    Advances in neuro-technology for mapping, manipulating, and monitoring molecularly defined cell types are rapidly advancing insight into neural circuits that regulate appetite. Here, we review these important tools and their applications in circuits that control food seeking and consumption. Technical capabilities provided by these tools establish a rigorous experimental framework for research into the neurobiology of hunger.

  9. The endocannabinoid system and appetite: relevance for food reward

    NARCIS (Netherlands)

    Jager, G.; Witkamp, R.F.

    2014-01-01

    Mounting evidence substantiates the central role of the endocannabinoid system (ECS) in the modulation of both homeostatic and hedonic elements of appetite and food intake. Conversely, feeding status and dietary patterns directly influence activity of the ECS. Following a general introduction on the

  10. Dietary fibres in the regulation of appetite and food intake

    DEFF Research Database (Denmark)

    Kristensen, Mette; Jensen, Morten Møller Georg

    2011-01-01

    of satiety. Particularly the ability of some dietary fibres to increase viscosity of intestinal contents offers numerous opportunities to affect appetite regulation. This may be linked to increased chyme viscosity, as linseed dietary fibre has water holding capacity and intrinsic viscosity which...

  11. Fish oil-supplementation increases appetite in healthy adults

    DEFF Research Database (Denmark)

    Damsbo-Svendsen, Signe; Rønsholdt, Mia Dybkjær; Lauritzen, Lotte

    2013-01-01

    (0.20; 2.22) lower after the fish oil-period. Furthermore, there was a supplement × gender-interaction on "desire to eat more" due to a score increase of 1.09. cm (0.28; 1.90) in women only. These results suggest that marine n-3 fatty acid may increase appetite. This finding would be potentially...

  12. The endocannabinoid system and appetite: relevance for food reward

    NARCIS (Netherlands)

    Jager, G.; Witkamp, R.F.

    2014-01-01

    Mounting evidence substantiates the central role of the endocannabinoid system (ECS) in the modulation of both homeostatic and hedonic elements of appetite and food intake. Conversely, feeding status and dietary patterns directly influence activity of the ECS. Following a general introduction on the

  13. Extinction of goal tracking also eliminates the conditioned reinforcing effects of an appetitive conditioned stimulus.

    Science.gov (United States)

    Kearns, David N; Tunstall, Brendan J; Marks, Katherine R; Weiss, Stanley J

    2012-02-01

    Previous studies have suggested that the effects of extinction are response-specific. The present study investigated whether an extinction treatment that eliminated goal tracking elicited by an appetitive conditioned stimulus (CS) would also eliminate the conditioned reinforcing effects of that CS. Rats were first trained on a goal-tracking procedure in which an auditory CS was paired with a food unconditioned stimulus. Animals learned to approach the location where the food was delivered. In a subsequent phase, rats in one group received extinction training that eliminated the goal-tracking elicited by the CS. Rats in the other group did not experience extinction of the food-paired CS. Then, both groups received a test for conditioned reinforcement in which leverpresses resulted in the brief presentation of the stimulus previously paired with food. This stimulus did not act as a conditioned reinforcer in the group that had been subjected to extinction training, but did serve as a conditioned reinforcer in the group that did not experience extinction. These results indicate that the effects of extinction generalize from the approach-eliciting to the conditioned reinforcing effects of an appetitive CS.

  14. Localization of neurotrophin receptors in olfactory epithelium and bulb.

    Science.gov (United States)

    Deckner, M L; Frisén, J; Verge, V M; Hökfelt, T; Risling, M

    1993-12-13

    We used in situ hybridization to localize trk, trkB and trkC mRNA, in rat and cat olfactory bulb. Expression of mRNA encoding truncated trkB receptors was seen in all layers, while only very modest full-length trkB expression could be detected. trkC hybridization was seen in all layers, most dense in the mitral cell layer. The localization of full-length tyrosine kinase trkB receptor in olfactory bulb and epithelium was examined with immunohistochemistry. trkB-like immunoreactivity was seen in the fila olfactoria, epithelium and in vitro, in olfactory sensory neurones. Since BDNF is expressed by olfactory sensory neurone target cells in the olfactory bulb, these data suggest that BDNF may act as a target derived neurotrophic factor in the primary olfactory system.

  15. Neural correlates of taste perception in congenital olfactory impairment.

    Science.gov (United States)

    Gagnon, Léa; Vestergaard, Martin; Madsen, Kristoffer; Karstensen, Helena G; Siebner, Hartwig; Tommerup, Niels; Kupers, Ron; Ptito, Maurice

    2014-09-01

    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 taste identification accuracy and its neural correlates using functional magnetic resonance imaging (fMRI) in 12 congenitally olfactory impaired individuals and 8 normosmic controls. Results showed that taste identification was worse in congenitally olfactory impaired compared to control subjects. The fMRI results demonstrated that olfactory impaired individuals had reduced activation in medial orbitofrontal cortex (mOFC) relative to normosmic subjects while tasting. In addition, olfactory performance as measured with the Sniffin' Sticks correlated positively with taste-induced blood-oxygen-level dependent (BOLD) signal increases in bilateral mOFC and anterior insula. Our data provide a neurological underpinning for the reduced taste perception in congenitally olfactory impaired individuals.

  16. Neural sensitivity to odorants in deprived and normal olfactory bulbs.

    Directory of Open Access Journals (Sweden)

    Francisco B Rodríguez

    Full Text Available Early olfactory deprivation in rodents is accompanied by an homeostatic regulation of the synaptic connectivity in the olfactory bulb (OB. However, its consequences in the neural sensitivity and discrimination have not been elucidated. We compared the odorant sensitivity and discrimination in early sensory deprived and normal OBs in anesthetized rats. We show that the deprived OB exhibits an increased sensitivity to different odorants when compared to the normal OB. Our results indicate that early olfactory stimulation enhances discriminability of the olfactory stimuli. We found that deprived olfactory bulbs adjusts the overall excitatory and inhibitory mitral cells (MCs responses to odorants but the receptive fields become wider than in the normal olfactory bulbs. Taken together, these results suggest that an early natural sensory stimulation sharpens the receptor fields resulting in a larger discrimination capability. These results are consistent with previous evidence that a varied experience with odorants modulates the OB's synaptic connections and increases MCs selectivity.

  17. Radiologic findings of olfactory neuroblastoma (Esthesioblastoma

    Directory of Open Access Journals (Sweden)

    Alpaslan Yavuz

    2013-12-01

    Full Text Available Olfactory neuroblastoma (ONB also known as esthesioblastoma is a rare malignant neoplasm originating from olfactive epitelium, usually locate in the olfactory region of the nasal cavity and anterior skull base. Few cases have been published in the literature yet. Detailed radiologic and histopathological examination is necessary for diagnosis and staging ONB. Prognosis is favorable especially for locally advanced tumors; regional and distant metastasis has been accepted as indicators of poor prognosis. Surgery and radiotherapy are the main therapeutic modalities in use today. We reported the x-ray graphic, B Mod-Doppler Ultrasound (US and Computed Tomography (CT findings of 64 years-old male with ONB in this presentation. J Clin Exp Invest 2013; 4 (4: 532-534

  18. 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.

  19. 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.

  20. Odors Discrimination by Olfactory Epithelium Biosensor

    Science.gov (United States)

    Liu, Qingjun; Hu, Ning; Ye, Weiwei; Zhang, Fenni; Wang, Hua; Wang, Ping

    2011-09-01

    Humans are exploring the bionic biological olfaction to sense the various trace components of gas or liquid in many fields. For achieving the goal, we endeavor to establish a bioelectronic nose system for odor detection by combining intact bioactive function units with sensors. The bioelectronic nose is based on the olfactory epithelium of rat and microelectrode array (MEA). The olfactory epithelium biosensor generates extracellular potentials in presence of odor, and presents obvious specificity under different odors condition. The odor response signals can be distinguished with each other effectively by signal sorting. On basis of bioactive MEA hybrid system and the improved signal processing analysis, the bioelectronic nose will realize odor discrimination by the specific feature of signals response to various odors.

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  5. Effect of vanadium on insulin sensitivity and appetite.

    Science.gov (United States)

    Wang, J; Yuen, V G; McNeill, J H

    2001-06-01

    Vanadium, a potent nonselective inhibitor of protein tyrosine phosphatases, has been shown to mimic many of the metabolic actions of insulin both in vivo and in vitro. The mechanism(s) of the effect of vanadium on the decrease in appetite and body weight in Zucker fa/fa rats, an insulin-resistant model, is still unclear. Because insulin may inhibit hypothalamic neuropeptide Y (NPY), which is known to be related to appetite, and increase leptin secretion in adipose tissue, we studied the possibility that the changes in appetite produced by vanadium may be linked to altered NPY levels in the hypothalamus. We also examined effects of vanadium on leptin. Zucker lean and fatty rats were chronically treated with bis(maltolato)oxovanadium(IV) (BMOV), an organic vanadium compound, in the drinking water. Plasma and adipose tissue leptin levels were measured by radioimmunoassay and immunoblotting, respectively. Hypothalamic NPY mRNA and peptide levels were measured using in situ hybridization and immunocytochemistry, respectively. BMOV treatment significantly reduced food intake, body fat, body weight, plasma insulin levels, and glucose levels in fatty Zucker rats. Fifteen minutes after insulin injection (5 U/kg, intravenous [IV]), circulating leptin levels (+100%) and adipose leptin levels (+60%) were elevated in BMOV-treated fatty rats, although these effects were not observed in untreated fatty rats. NPY mRNA levels in the arcuate nucleus (ARC) (-29%), NPY peptide levels in ARC (-31%), as well as in the paraventricular nucleus (PVN) (-37%) were decreased with BMOV treatment in these fatty rats. These data indicate that BMOV may increase insulin sensitivity in adipose tissue and decrease appetite and body fat by decreasing NPY levels in the hypothalamus. BMOV-induced reduction in appetite and weight gain along with normalized insulin levels in models of obesity, suggest its possible use as a therapeutic agent in obesity.

  6. Profound Olfactory Dysfunction in Myasthenia Gravis

    Science.gov (United States)

    Leon-Sarmiento, Fidias E.; Bayona, Edgardo A.; Bayona-Prieto, Jaime; Osman, Allen; Doty, Richard L.

    2012-01-01

    In this study we demonstrate that myasthenia gravis, an autoimmune disease strongly identified with deficient acetylcholine receptor transmission at the post-synaptic neuromuscular junction, is accompanied by a profound loss of olfactory function. Twenty-seven MG patients, 27 matched healthy controls, and 11 patients with polymiositis, a disease with peripheral neuromuscular symptoms analogous to myasthenia gravis with no known central nervous system involvement, were tested. All were administered the University of Pennsylvania Smell Identification Test (UPSIT) and the Picture Identification Test (PIT), a test analogous in content and form to the UPSIT designed to control for non-olfactory cognitive confounds. The UPSIT scores of the myasthenia gravis patients were markedly lower than those of the age- and sex-matched normal controls [respective means (SDs) = 20.15 (6.40) & 35.67 (4.95); p<0.0001], as well as those of the polymiositis patients who scored slightly below the normal range [33.30 (1.42); p<0.0001]. The latter finding, along with direct monitoring of the inhalation of the patients during testing, implies that the MG-related olfactory deficit is unlikely due to difficulties sniffing, per se. All PIT scores were within or near the normal range, although subtle deficits were apparent in both the MG and PM patients, conceivably reflecting influences of mild cognitive impairment. No relationships between performance on the UPSIT and thymectomy, time since diagnosis, type of treatment regimen, or the presence or absence of serum anti-nicotinic or muscarinic antibodies were apparent. Our findings suggest that MG influences olfactory function to the same degree as observed in a number of neurodegenerative diseases in which central nervous system cholinergic dysfunction has been documented. PMID:23082113

  7. 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.

  8. Olfactory dysfunction in persian patients suffering from parkinson's disease

    OpenAIRE

    Farzad Fatehi; Askar Ghorbani; Hamid Noorolahi; Mehdi Shams; Akbar Soltanzadeh

    2011-01-01

    Background Looking in literature reveals that aging is accompanied by olfactory dysfunction and hyposmia/anosmia is a common manifestation in some neurodegenerative disorders. Olfactory dysfunction is regarded as non-motor manifestations of Parkinson disease (PD). The main goal of this study was to examine the extent of olfactory dysfunction in Persian PD patients. Methods We used seven types of odors including rosewater, mint, lemon, garlic which were produced by Barij Essence Company in Ira...

  9. MRI of the olfactory bulbs and sulci in human fetuses

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, Robin; Grabar, Sophie; Kalifa, Gabriel; Adamsbaum, Catherine [Paris V, Faculte de Medecine, Department of Radiology, Hopital Saint Vincent de Paul, Paris Cedex 14 (France); Fallet-Bianco, Catherine [Hopital Sainte-Anne, Paris (France); Garel, Catherine [Hopital Robert Debre, Paris (France)

    2006-02-01

    There is limited knowledge of the MRI pattern of the development of fetal olfactory bulbs and sulci. To describe the MRI appearance of olfactory bulbs and sulci in normal in vivo fetuses according to gestational age. Olfactory bulbs and sulci were retrospectively assessed on brain MRI examinations of 88 normal fetuses between 24 and 39 weeks gestational age. Two reference centres were involved in the study and both used routine protocols that included axial and coronal T2- and T1-weighted sequences at 1.5 T. The results were compared both with the commonly used neuropathological data in the literature and with personal neuropathological data. Pearson's chi-squared test or Fisher's exact test were performed. One case of olfactory agenesis associated with CHARGE syndrome was identified. T2-weighted coronal sequences were the most sensitive for detecting olfactory bulbs and sulci. Olfactory sulci were significantly better detected from 30 weeks onwards (90.9-100%; P<0.001). MRI showed a posteroanterior development of these sulci. Olfactory bulbs were better detected from 30 to 34 weeks (80-90.9%; P<0.002). Comparison with neuropathological data confirmed the posteroanterior development of the sulci and showed an important delay in detection of the olfactory structures (bulbs and sulci). No difference was observed between the two centres involved. To date, fetal MRI can depict olfactory sulci from 30 weeks gestational age onwards and olfactory bulbs from 30 to 34 weeks gestational age. This preliminary reference standard is useful to assess the normality of the olfactory system and to diagnose olfactory agenesis. (orig.)

  10. Stingless bees use terpenes as olfactory cues to find resin sources.

    Science.gov (United States)

    Leonhardt, S D; Zeilhofer, S; Blüthgen, N; Schmitt, Thomas

    2010-09-01

    Insects largely rely on olfactory cues when seeking and judging information on nests, partners, or resources. Bees are known to use volatile compounds-besides visual cues-to find flowers suitable for pollen and nectar collection. Tropical stingless bees additionally collect large amounts of plant resins for nest construction, nest maintenance, nest defense, and to derive chemical constituents for their cuticular profiles. We here demonstrate that stingless bees of Borneo also use olfactory cues to find tree resins. They rely on volatile mono- and sesquiterpenes to locate or recognize known resin sources. Moreover, by modifying resin extracts, we found that stingless bees do not use the entire resin bouquet but relative proportions of several terpenes. In doing so, the bees are able to learn specific tree resin profiles and distinguish between tree species and partly even tree individuals.

  11. Olfactory metaphors in the online environment

    Directory of Open Access Journals (Sweden)

    Alina Ţenescu

    2015-08-01

    Full Text Available 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 category by examples taken from a corpus of excerpts of online non-specialized perfume discourse. Managing the issue of perception and description of fragrance in the online environment allows us an orientation of the research by multiple approaches of the semantics of perfume-speak: the recognition of essential aspects of perfume imaginary, with a focus on the olfactory metaphor in our research corpus; the analysis of sensory impressions and representations in online non-specialized discourse about fragrance. Our main aim is to organize conceptualizations of perfume notes into several categories, following the model inspired by the research of Lakoff and Johnson (Metaphors we live by, 1980.

  12. Neurally Encoding Time for Olfactory Navigation.

    Directory of Open Access Journals (Sweden)

    In Jun Park

    2016-01-01

    Full Text Available Accurately encoding time is one of the fundamental challenges faced by the nervous system in mediating behavior. We recently reported that some animals have a specialized population of rhythmically active neurons in their olfactory organs with the potential to peripherally encode temporal information about odor encounters. If these neurons do indeed encode the timing of odor arrivals, it should be possible to demonstrate that this capacity has some functional significance. Here we show how this sensory input can profoundly influence an animal's ability to locate the source of odor cues in realistic turbulent environments-a common task faced by species that rely on olfactory cues for navigation. Using detailed data from a turbulent plume created in the laboratory, we reconstruct the spatiotemporal behavior of a real odor field. We use recurrence theory to show that information about position relative to the source of the odor plume is embedded in the timing between odor pulses. Then, using a parameterized computational model, we show how an animal can use populations of rhythmically active neurons to capture and encode this temporal information in real time, and use it to efficiently navigate to an odor source. Our results demonstrate that the capacity to accurately encode temporal information about sensory cues may be crucial for efficient olfactory navigation. More generally, our results suggest a mechanism for extracting and encoding temporal information from the sensory environment that could have broad utility for neural information processing.

  13. Single amino acids in sucrose rewards modulate feeding and associative learning in the honeybee.

    Science.gov (United States)

    Simcock, Nicola K; Gray, Helen E; Wright, Geraldine A

    2014-10-01

    Obtaining the correct balance of nutrients requires that the brain integrates information about the body's nutritional state with sensory information from food to guide feeding behaviour. Learning is a mechanism that allows animals to identify cues associated with nutrients so that they can be located quickly when required. Feedback about nutritional state is essential for nutrient balancing and could influence learning. How specific this feedback is to individual nutrients has not often been examined. Here, we tested how the honeybee's nutritional state influenced the likelihood it would feed on and learn sucrose solutions containing single amino acids. Nutritional state was manipulated by pre-feeding bees with either 1M sucrose or 1M sucrose containing 100mM of isoleucine, proline, phenylalanine, or methionine 24h prior to olfactory conditioning of the proboscis extension response. We found that bees pre-fed sucrose solution consumed less of solutions containing amino acids and were also less likely to learn to associate amino acid solutions with odours. Unexpectedly, bees pre-fed solutions containing an amino acid were also less likely to learn to associate odours with sucrose the next day. Furthermore, they consumed more of and were more likely to learn when rewarded with an amino acid solution if they were pre-fed isoleucine and proline. Our data indicate that single amino acids at relatively high concentrations inhibit feeding on sucrose solutions containing them, and they can act as appetitive reinforcers during learning. Our data also suggest that select amino acids interact with mechanisms that signal nutritional sufficiency to reduce hunger. Based on these experiments, we predict that nutrient balancing for essential amino acids during learning requires integration of information about several amino acids experienced simultaneously.

  14. Destruction of the main olfactory epithelium reduces female sexual behavior and olfactory investigation in female mice

    OpenAIRE

    Keller, Matthieu; Douhard, Quentin; Baum, M.J.; Bakker, Julie

    2006-01-01

    We studied the contribution of the main olfactory system to mate recognition and sexual behavior in female mice. Female mice received an intranasal irrigation of either a zinc sulfate (ZnSO4) solution to destroy the main olfactory epithelium (MOE) or saline (SAL) to serve as control. ZnSO4-treated female mice were no longer able to reliably distinguish between volatile as well as nonvolatile odors from an intact versus a castrated male. Furthermore, sexual behavior in mating tests with a sexu...

  15. Effects of multivitamin-multimineral supplementation on appetite of stunted young Beninese children.

    Science.gov (United States)

    Dossa, R A M; Ategbo, E A D; van Raaij, J M A; de Graaf, C; Hautvast, J G A J

    2002-10-01

    In the developing world, food intake of young children is often insufficient for growth. Reduced appetite due to several factors including micronutrient deficiencies might be an explanation. We hypothesized that a multivitamin-multimineral supplementation will improve appetite of stunted children in south of Benin. Multivitamin-multimineral supplements (VITALIA-tablets) contain 11 vitamins and 8 minerals. Stunted children (Ht/Age Z score appetite were assessed once a week for the three weeks preceding and the three weeks following the six-week intervention period. Growth was additionally assessed 4 months after intervention. Each appetite test day, morbidity data and mother's report on child's appetite throughout the preceding day were recorded. Reported appetite, intake of test food and knee-heel length increased after supplementation in both groups (p appetite and growth of stunted young children.

  16. Recent progress of appetite regulation in central nervous system%中枢食欲调节研究进展

    Institute of Scientific and Technical Information of China (English)

    程笑冰; 宁光

    2009-01-01

    Concordant ingestion of appetite regulation internet is the basic physiological activity of human. Appetite regulation relates to complicate mechanisms and involves many systems and factors. Their impacting and controlling formed the appetite regulation internet. The hypothalamus plays a crucial role in re-cepting,integrating and releasing signals of energy status in central nervous system. The consummated con-struction of hypothalamus about appetite regulation and the finding of new regulation factors are very impor-tant for the learning of mechanism of obesity and diabetes and the development of drugs.%食欲调节网络的协调性摄食活动是维持人类生命的基本生理活动,食欲调节具有复杂而精细的调节机制,而下丘脑正是接受、整合与发放食欲调节信号、维持体重稳定的重要中枢.中枢神经系统或外周组织产生的具有促/抑食欲作用的神经内分泌因子在下丘脑形成复杂的食欲调节网络和相互投射的神经环路,对食欲进行精确的调控.不断完善下丘脑食欲调节区域,不断发现新的调控因子及其作用机制,对深入了解肥胖及糖尿病的病理生理机制及设计开发各种有效控制体重和血糖的药物有重大意义.

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

    Directory of Open Access Journals (Sweden)

    James C Walton

    Full Text Available Brain plasticity, in relation to new adult mammalian neurons generated in the subgranular zone of the hippocampus, has been well described. However, the functional outcome of new adult olfactory neurons born in the subventricular zone of the lateral ventricles is not clearly defined, as manipulating neurogenesis through various methods has given inconsistent and conflicting results in lab mice. Several small rodent species, including Peromyscus leucopus, display seasonal (photoperiodic brain plasticity in brain volume, hippocampal function, and hippocampus-dependent behaviors; plasticity in the olfactory system of photoperiodic rodents remains largely uninvestigated. We exposed adult male P. leucopus to long day lengths (LD and short day lengths (SD for 10 to 15 weeks and then examined olfactory bulb cell proliferation and survival using the thymidine analog BrdU, olfactory bulb granule cell morphology using Golgi-Cox staining, and behavioral investigation of same-sex conspecific urine. SD mice did not differ from LD counterparts in granular cell morphology of the dendrites or in dendritic spine density. Although there were no differences due to photoperiod in habituation to water odor, SD mice rapidly habituated to male urine, whereas LD mice did not. In addition, short day induced changes in olfactory behavior were associated with increased neurogenesis in the caudal plexiform and granule cell layers of the olfactory bulb, an area known to preferentially respond to water-soluble odorants. Taken together, these data demonstrate that photoperiod, without altering olfactory bulb neuronal morphology, alters olfactory bulb neurogenesis and olfactory behavior in Peromyscus leucopus.

  18. An Information Theoretic Model of Information Processing in the Drosophila Olfactory System: the Role of Inhibitory Neurons for System Efficiency

    Directory of Open Access Journals (Sweden)

    Faramarz eFaghihi

    2013-12-01

    Full Text Available Fruit flies (Drosophila melanogaster rely on their olfactory system to process environmental information. This information has to be transmitted without system-relevant loss by the olfactory system to deeper brain areas for learning. Here we study the role of several parameters of the fly's olfactory system and the environment and how they influence olfactory information transmission. We have designed an abstract model of the antennal lobe, the mushroom body and the inhibitory circuitry. Mutual information between the olfactory environment, simulated in terms of different odor concentrations, and a sub-population of intrinsic mushroom body neurons (Kenyon cells was calculated to quantify the efficiency of information transmission. With this method we study, on the one hand, the effect of different connectivity rates between olfactory projection neurons and firing thresholds of Kenyon cells. On the other hand, we analyze the influence of inhibition on mutual information between environment and mushroom body. Our simulations show an expected linear relation between the connectivity rate between the antennal lobe and the mushroom body and firing threshold of the Kenyon cells to obtain maximum mutual information for both low and high odor concentrations. However, contradicting all-day experiences, high odor concentrations cause a drastic, and unrealistic, decrease in mutual information for all connectivity rates compared to low concentration. But when inhibition on the mushroom body is included, mutual information remains at high levels independent of other system parameters. This finding points to a pivotal role of inhibition in fly information processing without which the system's efficiency will be substantially reduced.

  19. Environmental toxicants-induced immune responses in the olfactory mucosa

    Directory of Open Access Journals (Sweden)

    Fumiaki Imamura

    2016-11-01

    Full Text Available Olfactory sensory neurons (OSNs are the receptor cells for the sense of smell. Although cell bodies are located in the olfactory mucosa of the nasal cavity, OSN axons directly project to the olfactory bulb that is a component of the central nervous system (CNS. Because of this direct and short connection from this peripheral tissue to the CNS, the olfactory system has attracted attention as a port-of-entry for environmental toxicants that may cause neurological dysfunction. Selected viruses can enter the olfactory bulb via the olfactory mucosa, and directly affect the CNS. On the other hand, environmental toxicants may induce inflammatory responses in the olfactory mucosa, including infiltration of immune cells and production of inflammatory cytokines. In addition, these inflammatory responses cause the loss of OSNs that are then replaced with newly generated OSNs that re-connect to the olfactory bulb after inflammation has subsided. It is now known that immune cells and cytokines in the olfactory mucosa play important roles in both degeneration and regeneration of OSNs. Thus, the olfactory system is a unique neuroimmune interface where interaction between nervous and immune systems in the periphery significantly affects the structure, neuronal circuitry, and immunological status of the CNS. The mechanisms by which immune cells regulate OSN loss and the generation of new OSNs are, however, largely unknown. To help develop a better understanding of the mechanisms involved, we have provided a review of key research that has investigated how the immune response in the olfactory mucosa affects the pathophysiology of OSNs.

  20. Sensory representation and learning-related plasticity in mushroom body extrinsic feedback neurons of the protocerebral tract.

    Science.gov (United States)

    Haehnel, Melanie; Menzel, Randolf

    2010-01-01

    Gamma-aminobutyric acid immunoreactive feedback neurons of the protocerebral tract are a major component of the honeybee mushroom body. They have been shown to be subject to learning-related plasticity and provide putative inhibitory input to Kenyon cells and the pedunculus extrinsic neuron, PE1. We hypothesize, that learning-related modulation in these neurons is mediated by varying the amount of inhibition provided by feedback neurons. We performed Ca(2+) imaging recordings of populations of neurons of the protocerebral-calycal tract (PCT) while the bees were conditioned in an appetitive olfactory paradigm and their behavioral responses were quantified using electromyographic recordings from M17, the muscle which controls the proboscis extension response. The results corroborate findings from electrophysiological studies showing that PCT neurons respond to sucrose and odor stimuli. The odor responses are concentration dependent. Odor and sucrose responses are modulated by repeated stimulus presentations. Furthermore, animals that learned to associate an odor with sucrose reward responded to the repeated presentations of the rewarded odor with less depression than they did to an unrewarded and a control odor.

  1. Differential effects of amphetamines-induced neurotoxicity on appetitive and aversive Pavlovian conditioning in mice.

    Science.gov (United States)

    Achat-Mendes, Cindy; Ali, Syed F; Itzhak, Yossef

    2005-06-01

    The abuse of substituted amphetamines such as methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA/Ecstasy) can result in neurotoxicity, manifested as the depletion of dopamine (DA) and 5-hydroxytriptamine (5-HT; serotonin) axon terminal markers in humans and animal models. Human METH and MDMA users exhibit impairments in memory and executive functions, which may be a direct consequence of the neurotoxic potential of amphetamines. The objective of this study was to investigate the influence of amphetamines-induced neurotoxicity on Pavlovian learning. Using mouse models of selective DA neurotoxicity (METH; 5 mg/kg x 3), selective 5-HT neurotoxicity (fenfluramine /FEN; 25 mg/kg x 4) and dual DA and 5-HT neurotoxicity (MDMA; 15 mg/kg x 4), appetitive and aversive conditioning were investigated. Dopaminergic neurotoxicity significantly impaired METH and cocaine conditioned place preference (CPP), but had no effect on LiCl-induced conditioned place aversion (CPA). In contrast, serotonergic neurotoxicity significantly enhanced CPP, and had no effect on CPA. Dual dopaminergic/serotonergic neurotoxicity had no apparent effect on CPP; however, CPA was significantly attenuated. Postmortem analysis revealed that significantly diminished levels of DA and 5-HT markers persisted in the striatum, frontal cortex, hippocampus, and amygdala. These findings suggest that amphetamines-induced dopaminergic and serotonergic neurotoxicity exert opposing influences on the affective state produced by subsequent drug reward, while dual dopaminergic/serotonergic neurotoxicity impairs associative learning of aversive conditioning. Furthermore, results revealed that amphetamines-induced DA and 5-HT neurotoxicity modulates appetitive Pavlovian conditioning similar to other DA and 5-HT neurotoxins. Modulation of Pavlovian conditioning by amphetamines-induced neurotoxicity may be relevant to compulsive drug-seeking behavior in METH and MDMA abusers.

  2. Effect of viscosity on appetite and gastro-intestinal hormones

    DEFF Research Database (Denmark)

    Zijlstra, Nicolien; Mars, Monica; de Wijk, René A

    2009-01-01

    /m(2)) participated in this cross-over study. Subjects received a fixed amount of a chocolate flavored milk-based liquid or semi-solid product similar in energy density and macronutrient composition. Before intake and 15, 30, 60 and 90 min thereafter, appetite was rated and blood was drawn to determine...... glucose, CCK-8, active ghrelin, desacyl ghrelin and GLP-1 concentrations. After the last blood withdrawal, subjects were offered a chocolate cake meal to consume ad libitum. In the appetite ratings we observed a small effect showing that the semi-solid product is apparently considered as more satisfying...... product effect (p 0.004). Concentrations were consistently higher after intake of the semi-solid product. Ad libitum intake of the chocolate cake was 102+/-55 g after the liquid and 96+/-46 g after the semi-solid product (ns). The results of our study show a similar response of the gastro...

  3. Correlation between echographic gastric emptying and appetite: influence of psyllium.

    Science.gov (United States)

    Bergmann, J F; Chassany, O; Petit, A; Triki, R; Caulin, C; Segrestaa, J M

    1992-01-01

    The correlation between ultrasonographic gastric emptying and appetite was studied. Echographic evaluation of gastric emptying by measurement of the antral vertical diameter and assessment of sensations of hunger and satiety using analogue visual scales were performed simultaneously in 12 healthy volunteers. Measurements were carried out after the intake of 10.8 g psyllium or placebo in a randomised, crossover, double blind trial. The correlation between echographic gastric emptying and sensations of hunger and satiety was excellent (p < 0.001) after the intake of either psyllium or placebo. Psyllium significantly delayed gastric emptying from the third hour after a meal. It increased the sensation of satiety and decreased hunger at the sixth hour after the meal. The association between echographic measurement and visual scales is a simple method of evaluating the relationship between the stomach and appetite. The pharmacodynamic effect of psyllium should be confirmed by longterm therapeutic trials. PMID:1398229

  4. Ghrelin, Appetite Regulation, and Food Reward: Interaction with Chronic Stress

    Directory of Open Access Journals (Sweden)

    Yolanda Diz-Chaves

    2011-01-01

    Full Text Available Obesity has become one of the leading causes of illness and mortality in the developed world. Preclinical and clinical data provide compelling evidence for ghrelin as a relevant regulator of appetite, food intake, and energy homeostasis. In addition, ghrelin has recently emerged as one of the major contributing factors to reward-driven feeding that can override the state of satiation. The corticotropin-releasing-factor system is also directly implicated in the regulation of energy balance and may participate in the pathophysiology of obesity and eating disorders. This paper focuses on the role of ghrelin in the regulation of appetite, on its possible role as a hedonic signal involved in food reward, and on its interaction with the corticotropin-releasing-factor system and chronic stress.

  5. Peripheral Insulin Doesn’t Alter Appetite of Broiler Chicks

    Directory of Open Access Journals (Sweden)

    Lei Liu

    2016-09-01

    Full Text Available An experiment was conducted to investigate the effect of peripheral insulin treatment on appetite in chicks. Six-d-age chicks with ad libitum feeding or fasting for 3 h before injection received a subcutaneous injection of 0, 1, 3, 5, 10, or 20 IU of insulin or vehicle (saline. The results showed peripheral insulin treatment (1 to 20 IU did not alter significantly the feed intake in chicks under either ad libitum feeding or fasting conditions within 4 h (p>0.05. Compared with the control, plasma glucose concentration was significantly decreased after insulin treatment of 3, 5, 10, and 20 IU for 4 h in chicks with ad libitum feeding (p0.05. All results suggest peripheral administration of insulin has no effect on appetite in chicks.

  6. Gut-Brain Nutrient Signaling: Appetition vs. Satiation

    Science.gov (United States)

    Sclafani, Anthony

    2012-01-01

    Multiple hormonal and neural signals are generated by ingested nutrients that limit meal size and suppress postmeal eating. However, the availability of sugar-rich and fat-rich foods can override these satiation/satiety signals and lead to overeating and obesity. The palatable flavor of these foods is one factor that promotes overeating, but sugar and fat also have postoral actions that can stimulate eating and increase food preferences. This is revealed in conditioning studies in which rodents consume flavored solutions paired with intragastric sugar or fat infusions. The significant flavor preferences and increased intake produced by the nutrient infusions appear to involve stimulatory gut-brain signals, referred to here as appetition signals, that are distinct from the satiation signals that suppress feeding. Newly developed rapid conditioning protocols may facilitate the study of postoral appetition processes. PMID:22664300

  7. Gut-brain nutrient signaling. Appetition vs. satiation.

    Science.gov (United States)

    Sclafani, Anthony

    2013-12-01

    Multiple hormonal and neural signals are generated by ingested nutrients that limit meal size and suppress postmeal eating. However, the availability of sugar-rich and fat-rich foods can override these satiation/satiety signals and lead to overeating and obesity. The palatable flavor of these foods is one factor that promotes overeating, but sugar and fat also have postoral actions that can stimulate eating and increase food preferences. This is revealed in conditioning studies in which rodents consume flavored solutions paired with intragastric sugar or fat infusions. The significant flavor preferences and increased intake produced by the nutrient infusions appear to involve stimulatory gut-brain signals, referred to here as appetition signals, that are distinct from the satiation signals that suppress feeding. Newly developed rapid conditioning protocols may facilitate the study of postoral appetition processes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. 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.

  9. 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

    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...

  10. The Presentation of Olfactory-Trigeminal Mixed Stimuli Increases the Response to Subsequent Olfactory Stimuli.

    Science.gov (United States)

    Walliczek-Dworschak, Ute; Poncelet, Johan; Baum, Daniel; Baki, Ramona; Sinding, Charlotte; Warr, Jonathan; Hummel, Thomas

    2017-01-09

    The aim of this study was to evaluate the effect of (1) the addition of trigeminal stimuli to an olfactory stimulus and (2) the congruence in the odorous mixture after repeated odor presentation. Twenty-five normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition, orange odor; congruent condition, orange odor + CO2; incongruent condition, orange odor + l-isopulegol), and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D; peak to peak N1P2 at electrode positions Cz, Fz, and Pz; response amplitudes between H3 and DH). The addition of CO2 modified the perception of orange odor, pronouncing a fruity note, whereas the addition of l-isopulegol as a DH pronounced the l-isopulegol note. This study provides evidence that incongruent trigeminal-olfactory stimulants increase the response to subsequent olfactory stimulus.

  11. Recovery of Olfactory Function in Postviral Olfactory Dysfunction Patients after Acupuncture Treatment

    Directory of Open Access Journals (Sweden)

    Qi Dai

    2016-01-01

    Full Text Available Introduction. The aims of this study were to assess the impact of traditional Chinese acupuncture (TCA in postviral olfactory dysfunction (PVOD patients who were refractory to standardized treatment and to compare the results with the impact observed in an observation group. Methods. Fifty patients who presented to the outpatient clinic with PVOD and were refractory to standardized treatment were included: 25 were treated with TCA and 25 patients were simply observed. A subjective olfactory test was performed using the University of Pennsylvania Smell Identification Test (UPSIT. The effects of TCA were compared with the results obtained in the observation group. Results. Improved olfactory function was observed in eleven patients treated with TCA compared with four patients in the observation group. This study revealed significantly improved olfactory function outcomes in patients who underwent acupuncture compared with the observation group. No significant differences in olfaction recovery were found according to age, gender, or duration of disease between the two groups; however, hyposmic patients recovered at a higher rate than anosmic patients. Conclusion. TCA may aid the treatment of PVOD patients who are refractory to drugs or other therapies.

  12. 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.

  13. 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.

  14. Comparison of the canine and human olfactory receptor gene repertoires

    NARCIS (Netherlands)

    Quignon, P; Kirkness, E; Cadieu, E; Touleimat, N; Guyon, R; Renier, C; Hitte, C; Andre, C; Fraser, C; Galibert, F

    2003-01-01

    Background: Olfactory receptors (ORs), the first dedicated molecules with which odorants physically interact to arouse an olfactory sensation, constitute the largest gene family in vertebrates, including around 900 genes in human and 1,500 in the mouse. Whereas dogs, like many other mammals, have a

  15. Dietary sodium protects fish against copper-induced olfactory impairment.

    Science.gov (United States)

    Azizishirazi, Ali; Dew, William A; Bougas, Berenice; Bernatchez, Louis; Pyle, Greg G

    2015-04-01

    Exposure to low concentrations of copper impairs olfaction in fish. To determine the transcriptional changes in the olfactory epithelium induced by copper exposure, wild yellow perch (Perca flavescens) were exposed to 20 μg/L of copper for 3 and 24h. A novel yellow perch microarray with 1000 candidate genes was used to measure differential gene transcription in the olfactory epithelium. While three hours of exposure to copper changed the transcription of only one gene, the transcriptions of 70 genes were changed after 24h of exposure to copper. Real-time PCR was utilized to determine the effect of exposure duration on two specific genes of interest, two sub-units of Na/K-ATPase. At 24 and 48 h, Na/K-ATPase transcription was down-regulated by copper at olfactory rosettes. As copper-induced impairment of Na/K-ATPase activity in gills can be ameliorated by increased dietary sodium, rainbow trout (Oncorhynchus mykiss) were used to determine if elevated dietary sodium was also protective against copper-induced olfactory impairment. Measurement of the olfactory response of rainbow trout using electro-olfactography demonstrated that sodium was protective of copper-induced olfactory dysfunction. This work demonstrates that the transcriptions of both subunits of Na/K-ATPase in the olfactory epithelium of fish are affected by Cu exposure, and that dietary Na protects against Cu-induced olfactory dysfunction.

  16. 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…

  17. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    OpenAIRE

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing ...

  18. 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…

  19. Kappe neurons, a novel population of olfactory sensory neurons

    Science.gov (United States)

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-02-01

    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 are identified by their Go-like immunoreactivity, and show a distinct spatial distribution within the olfactory epithelium, similar to, but significantly different from that of crypt neurons. Furthermore, kappe neurons project to a single identified target glomerulus within the olfactory bulb, mdg5 of the mediodorsal cluster, whereas crypt neurons are known to project exclusively to the mdg2 glomerulus. Kappe neurons are negative for established markers of ciliated, microvillous and crypt neurons, but appear to have microvilli. Kappe neurons constitute the fourth type of olfactory sensory neurons reported in teleost fishes and their existence suggests that encoding of olfactory stimuli may require a higher complexity than hitherto assumed already in the peripheral olfactory system.

  20. Hypothalamic opioid-melanocortin appetitive balance and addictive craving.

    Science.gov (United States)

    Reece, Albert Stuart

    2011-01-01

    Whilst the parallels between drug and food craving are receiving increasing attention, the recently elucidated complex physiology of the hypothalamic appetite regulatory centres has been largely overlooked in the efforts to understand drug craving which is one of the most refractory and problematic aspects of drug and behavioural addictions. Important conceptual gains could be made by researchers from both appetite and addiction neuroscience if they were to have an improved understanding of each others' disciplines. It is well known in addiction medicine that the use of many substances is elevated in opiate dependency. There is voluminous evidence of very high rates of drug use in opiate agonist maintained patients, and the real possibility exists that opiate agonist therapy therefore increases drug craving. Conversely, opiate antagonist therapy with naloxone or naltrexone has been shown to reduce most chemical and behavioural addictions, and naltrexone is now being developed together with bupropion as the anti-obesity drug "Contrave". Hypothalamic melanocortins, particularly α-MSH, are known to constitute the main brake to consumptive behaviour of food. There is a well described antagonism between melanocortins and opioids at many loci including the hypothalamus. Administration of exogenous opiates is known to both suppress α-MSH and to stimulate hedonic food consumption. Opiate maintenance programs are associated with weight gain. As monoamines, opioids and cannabinoids are known to be involved in appetite regulation, and as endorphin opioids are known to be perturbed in other addictions, further exploration of the hypothalamic appetite regulatory centre would appear to be an obvious, albeit presently largely overlooked, locus in which to study drug and other craving mechanisms. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Appetite regulation in Schizothorax prenanti by three CART genes.

    Science.gov (United States)

    Yuan, Dengyue; Wei, Rongbin; Wang, Tao; Wu, Yuanbing; Lin, Fangjun; Chen, Hu; Liu, Ju; Gao, Yundi; Zhou, Chaowei; Chen, Defang; Li, Zhiqiong

    2015-12-01

    In recent years, cocaine- and amphetamine-regulated transcript (CART) has received much attention as mediators of appetite regulation in mammals. However, the involvement of CART in the feeding behavior of teleosts has not been well understood. In this study, three distinct CARTs were cloned from the Schizothorax prenanti (S. prenanti). Real-time quantitative PCR were applied to characterize the tissue distribution and appetite regulatory effects of CARTs in S. prenanti. The S. prenanti CART-1, CART-2 and CART-3 full-length cDNA sequences were 597 bp, 694 bp and 749 bp in length, encoding the peptides of 125, 120 and 104 amino acid residues, respectively. All the S. prenanti CARTs consisted of three exons and two introns. Tissue distribution analysis showed that the high mRNA levels of S. prenanti CART-1 were observed in the telencephalon and eye, followed by the hypothalamus, myelencephalon, and mesencephalon. The S. prenanti CART-2 mRNA was mainly found in the mesencephalon, hypothalamus, telencephalon and myelencephalon. The S. prenanti CART-3 mRNA was widely distributed among the tissues, with the high levels in the hypothalamus and foregut. In the periprandial experiment, all three CARTs mRNA expressions in the hypothalamus were highly elevated after a meal, suggesting that CARTs are postprandial satiety signals. In the fasting experiment, all three CARTs mRNA expressions decreased after fasting and increased after refeeding, suggesting that CARTs might be involved in regulation of appetite in the S. prenanti.

  2. The endocannabinoid system and appetite: relevance for food reward.

    Science.gov (United States)

    Jager, Gerry; Witkamp, Renger F

    2014-06-01

    Mounting evidence substantiates the central role of the endocannabinoid system (ECS) in the modulation of both homeostatic and hedonic elements of appetite and food intake. Conversely, feeding status and dietary patterns directly influence activity of the ECS. Following a general introduction on the functioning of the ECS, the present review specifically addresses its role in the modulation of hedonic eating. Humans possess strong motivational systems triggered by rewarding aspects of food. Food reward is comprised of two components: one appetitive (orienting towards food); the other consummatory (hedonic evaluation), also referred to as 'wanting' and 'liking', respectively. Endocannabinoid tone seems to influence both the motivation to feed and the hedonic value of foods, probably by modifying palatability. Human physiology underlying hedonic eating is still not fully understood. A better understanding of the role of the ECS in the rewarding value of specific foods or diets could offer new possibilities to optimise the balance between energy and nutrient intake for different target groups. These groups include the obese and overweight, and potentially individuals suffering from malnutrition. Examples for the latter group are patients with disease-related anorexia, as well as the growing population of frail elderly suffering from persistent loss of food enjoyment and appetite resulting in malnutrition and involuntary weight loss. It has become clear that the psychobiology of food hedonics is extremely complex and the clinical failure of CB1 inverse agonists including rimonabant (Accomplia®) has shown that 'quick wins' in this field are unlikely.

  3. Appetite Response among Those Susceptible or Resistant to Obesity

    Directory of Open Access Journals (Sweden)

    Rachel C. Brown

    2014-01-01

    Full Text Available An alternative approach in determining cause, treatment, and prevention of obesity is to study those who appear resistant to the obesogenic environment. We examined appetite responses in 33 obesity resistant individuals (ORI versus 28 obesity susceptible individuals (OSI. Fingerprick blood samples to measure ghrelin, total peptide YY (PYY, leptin, glucose, and insulin along with appetite ratings were collected at baseline and 15, 30, 60, 120, and 180 min following consumption of a standardized meal. Fasting, area under the curve (AUC, peak/nadir, and time to peak/nadir were compared. Participants completed the three factor eating questionnaire (TFEQ. No significant differences were observed for ghrelin or PYY. Higher leptin concentrations in the OSI disappeared after controlling for percent body fat (%BF. Significant differences in appetite ratings included a lower hunger nadir among OSI compared with ORI (P=0.017. Dietary restraint (P<0.001 and disinhibition (P<0.001 were lower in ORI compared with OSI, with and without adjustment for %BF. Given the differential body weight of the study groups, similar observed ghrelin concentrations were unexpected, perhaps indicating OSI and ORI respond differently to the same ghrelin concentration. Also ORI response to hunger appears different as they exhibit lower levels of dietary restraint and disinhibition compared with OSI.

  4. Brain structure, executive function and appetitive traits in adolescent obesity.

    Science.gov (United States)

    de Groot, C J; van den Akker, E L T; Rings, E H H M; Delemarre-van de Waal, H A; van der Grond, J

    2017-08-01

    Children with obesity show differences in brain structure, executive function and appetitive traits when compared with lean peers. Little is known on the relationship between brain structure and these traits. To investigate the relationship between differences in brain structure and executive function and appetitive traits, in obese and lean adolescents. MRI was used to measure cortical thickness and subcortical volumes. Executive function was measured by a Stop Signal-and a Choice Delay Task. Appetitive traits were measured using the Child Eating Behaviour Questionnaire. Adolescents with obesity had greater volumes of the pallidum; 1.78 mL (SE 0.03, p=0.014), when compared with controls; 1.65 mL (SE 0.02). In the group with obesity, greater pallidum volume was positively associated with the ability to delay reward in the Choice Delay Task (p=0.012). The association between pallidum volumes and Choice Delay Task in obese adolescents supports the hypothesis that the pallidum plays an important role in executive dysfunction in obese children. © 2016 World Obesity Federation.

  5. Progress in bionic information processing techniques for an electronic nose based on olfactory models

    Institute of Scientific and Technical Information of China (English)

    LI Guang; FU Jun; ZHANG Jia; ZHENG JunBao

    2009-01-01

    As a novel bionic analytical technique, an electronic nose, inspired by the mechanism of the biological olfactory system and integrated with modern sensing technology, electronic technology and pattern recognition technology, has been widely used in many areas. Moreover, recent basic research findings in biological olfaction combined with computational neuroscience promote its development both in methodology and application. In this review, the basic information processing principle of biological olfaction and artificial olfaction are summarized and compared, and four olfactory models and their applications to electronic noses are presented. Finally, a chaotic olfactory neural network is detailed and the utilization of several biologically oriented learning rules and its spatiotemporal dynamic prop-ties for electronic noses are discussed. The integration of various phenomena and their mechanisms for biological olfaction into an electronic nose context for information processing will not only make them more bionic, but also perform better than conventional methods. However, many problems still remain, which should be solved by further cooperation between theorists and engineers.

  6. Destruction of the main olfactory epithelium reduces female sexual behavior and olfactory investigation in female mice.

    Science.gov (United States)

    Keller, Matthieu; Douhard, Quentin; Baum, Michael J; Bakker, Julie

    2006-05-01

    We studied the contribution of the main olfactory system to mate recognition and sexual behavior in female mice. Female mice received an intranasal irrigation of either a zinc sulfate (ZnSO4) solution to destroy the main olfactory epithelium (MOE) or saline (SAL) to serve as control. ZnSO4-treated female mice were no longer able to reliably distinguish between volatile as well as nonvolatile odors from an intact versus a castrated male. Furthermore, sexual behavior in mating tests with a sexually experienced male was significantly reduced in ZnSO4-treated female mice. Vomeronasal function did not seem to be affected by ZnSO4 treatment: nasal application of male urine induced similar levels of Fos protein in the mitral and granule cells of the accessory olfactory bulb (AOB) of ZnSO4 as well as SAL-treated female mice. Likewise, soybean agglutinin staining, which stains the axons of vomeronasal neurons projecting to the glomerular layer of the AOB was similar in ZnSO4-treated female mice compared to SAL-treated female mice. By contrast, a significant reduction of Fos in the main olfactory bulb was observed in ZnSO4-treated females in comparison to SAL-treated animals, confirming a substantial destruction of the MOE. These results show that the MOE is primarily involved in the detection and processing of odors that are used to localize and identify the sex and endocrine status of conspecifics. By contrast, both the main and accessory olfactory systems contribute to female sexual receptivity in female mice.

  7. Endothelin uncouples gap junctions in sustentacular cells and olfactory ensheathing cells of the olfactory mucosa.

    Science.gov (United States)

    Le Bourhis, Mikaël; Rimbaud, Stéphanie; Grebert, Denise; Congar, Patrice; Meunier, Nicolas

    2014-09-01

    Several factors modulate the first step of odour detection in the rat olfactory mucosa (OM). Among others, vasoactive peptides such as endothelin might play multifaceted roles in the different OM cells. Like their counterparts in the central nervous system, the olfactory sensory neurons are encompassed by different glial-like non-neuronal OM cells; sustentacular cells (SCs) surround their cell bodies, whereas olfactory ensheathing cells (OECs) wrap their axons. Whereas SCs maintain both the structural and ionic integrity of the OM, OECs assure protection, local blood flow control and guiding of olfactory sensory neuron axons toward the olfactory bulb. We previously showed that these non-neuronal OM cells are particularly responsive to endothelin in vitro. Here, we confirmed that the endothelin system is strongly expressed in the OM using in situ hybridization. We then further explored the effects of endothelin on SCs and OECs using electrophysiological recordings and calcium imaging approaches on both in vitro and ex vivo OM preparations. Endothelin induced both robust calcium signals and gap junction uncoupling in both types of cells. This latter effect was mimicked by carbenoxolone, a known gap junction uncoupling agent. However, although endothelin is known for its antiapoptotic effect in the OM, the uncoupling of gap junctions by carbenoxolone was not sufficient to limit the cellular death induced by serum deprivation in OM primary culture. The functional consequence of the endothelin 1-induced reduction of the gap junctional communication between OM non-neuronal cells thus remains to be elucidated. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  8. Understanding smell--the olfactory stimulus problem.

    Science.gov (United States)

    Auffarth, Benjamin

    2013-09-01

    The main problem with sensory processing is the difficulty in relating sensory input to physiological responses and perception. This is especially problematic at higher levels of processing, where complex cues elicit highly specific responses. In olfaction, this relationship is particularly obfuscated by the difficulty of characterizing stimulus statistics and perception. The core questions in olfaction are hence the so-called stimulus problem, which refers to the understanding of the stimulus, and the structure-activity and structure-odor relationships, which refer to the molecular basis of smell. It is widely accepted that the recognition of odorants by receptors is governed by the detection of physico-chemical properties and that the physical space is highly complex. Not surprisingly, ideas differ about how odor stimuli should be classified and about the very nature of information that the brain extracts from odors. Even though there are many measures for smell, there is none that accurately describes all aspects of it. Here, we summarize recent developments in the understanding of olfaction. We argue that an approach to olfactory function where information processing is emphasized could contribute to a high degree to our understanding of smell as a perceptual phenomenon emerging from neural computations. Further, we argue that combined analysis of the stimulus, biology, physiology, and behavior and perception can provide new insights into olfactory function. We hope that the reader can use this review as a competent guide and overview of research activities in olfactory physiology, psychophysics, computation, and psychology. We propose avenues for research, particularly in the systematic characterization of receptive fields and of perception. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Neural circuits mediating olfactory-driven behavior in fish

    Directory of Open Access Journals (Sweden)

    Florence eKermen

    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.

    Directory of Open Access Journals (Sweden)

    M Cristina Antal

    Full Text Available 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.

  11. Olfactory Mucosa Tissue Based Biosensor for Bioelectronic Nose

    Science.gov (United States)

    Liu, Qingjun; Ye, Weiwei; Yu, Hui; Hu, Ning; Cai, Hua; Wang, Ping

    2009-05-01

    Biological olfactory system can distinguish thousands of odors. In order to realize the biomimetic design of electronic nose on the principle of mammalian olfactory system, we have reported bioelectronic nose based on cultured olfactory cells. In this study, the electrical property of the tissue-semiconductor interface was analyzed by the volume conductor theory and the sheet conductor model. Olfactory mucosa tissue of rat was isolated and fixed on the surface of the light-addressable potentiometric sensor (LAPS), with the natural stations of the neuronal populations and functional receptor unit of the cilia well reserved. By the extracellular potentials of the olfactory receptor cells of the mucosa tissue monitored, both the simulation and the experimental results suggested that this tissue-semiconductor hybrid system was sensitive to odorants stimulation.

  12. A spiking neural network model of self-organized pattern recognition in the early mammalian olfactory system

    Directory of Open Access Journals (Sweden)

    Bernhard A. Kaplan

    2014-02-01

    Full Text Available Olfactory sensory information passes through several processing stages before an odor percept emerges. The question how the olfactory system learns to create odor representations linking those different levels and how it learns to connect and discriminate between them is largely unresolved. We present a large-scale network model with single and multi-compartmental Hodgkin-Huxley type model neurons representing olfactory receptor neurons (ORNs in the epithelium, periglomerular cells, mitral/tufted cells and granule cells in the olfactory bulb (OB, and three types of cortical cells in the piriform cortex (PC. Odor patterns are calculated based on affinities between ORNs and odor stimuli derived from physico-chemical descriptors of behaviorally relevant real-world odorants. The properties of ORNs were tuned to show saturated response curves with increasing concentration as seen in experiments. On the level of the OB we explored the possibility to use a fuzzy concentration interval code, which was implemented through dendro-dendritic inhibition leading to winner-take-all like dynamics between mitral/tufted cells belonging to the same glomerulus. The connectivity from mitral/tuftedcells to PC neurons was self-organized from a mutual information measure and by using a competitive Hebbian-Bayesian learning algorithm based on the response patterns of mitral/tufted cells to different odors yielding a distributed feed-forward projection to the PC. The PC was implemented as a modular attractor network with a recurrent connectivity that was likewiseorganized through Hebbian-Bayesian learning. We demonstrate the functionality of the model in a one-sniff-learning and recognition task on a set of 50 odorants. Furthermore, we study its robustness against noise on the receptor level and its ability to perform concentration invariant odor recognition. Moreover, we investigate the pattern completion capabilities of the system and rivalry dynamics for odor mixtures.

  13. A spiking neural network model of self-organized pattern recognition in the early mammalian olfactory system.

    Science.gov (United States)

    Kaplan, Bernhard A; Lansner, Anders

    2014-01-01

    Olfactory sensory information passes through several processing stages before an odor percept emerges. The question how the olfactory system learns to create odor representations linking those different levels and how it learns to connect and discriminate between them is largely unresolved. We present a large-scale network model with single and multi-compartmental Hodgkin-Huxley type model neurons representing olfactory receptor neurons (ORNs) in the epithelium, periglomerular cells, mitral/tufted cells and granule cells in the olfactory bulb (OB), and three types of cortical cells in the piriform cortex (PC). Odor patterns are calculated based on affinities between ORNs and odor stimuli derived from physico-chemical descriptors of behaviorally relevant real-world odorants. The properties of ORNs were tuned to show saturated response curves with increasing concentration as seen in experiments. On the level of the OB we explored the possibility of using a fuzzy concentration interval code, which was implemented through dendro-dendritic inhibition leading to winner-take-all like dynamics between mitral/tufted cells belonging to the same glomerulus. The connectivity from mitral/tufted cells to PC neurons was self-organized from a mutual information measure and by using a competitive Hebbian-Bayesian learning algorithm based on the response patterns of mitral/tufted cells to different odors yielding a distributed feed-forward projection to the PC. The PC was implemented as a modular attractor network with a recurrent connectivity that was likewise organized through Hebbian-Bayesian learning. We demonstrate the functionality of the model in a one-sniff-learning and recognition task on a set of 50 odorants. Furthermore, we study its robustness against noise on the receptor level and its ability to perform concentration invariant odor recognition. Moreover, we investigate the pattern completion capabilities of the system and rivalry dynamics for odor mixtures.

  14. The medial orbitofrontal cortex encodes a general unsigned value signal during anticipation of both appetitive and aversive events.

    Science.gov (United States)

    Metereau, Elise; Dreher, Jean-Claude

    2015-02-01

    The medial orbitofrontal cortex (mOFC)/ventromedial prefrontal cortex (vmPFC) has been proposed to signal the expected value of rewards when learning stimuli-rewards associations. Yet, it is still unclear whether identical or distinct orbitofrontal cortex regions encode expected rewards and punishments at the time of the cue during appetitive and aversive classical conditioning. Moreover, it is unknown whether anticipation of different types of positive and negative reinforcers differentially influence specific orbitofrontal cortex regions. To answer these questions, this study investigated whether the human mOFC/vmPFC region encodes a general unsigned anticipatory value signal for different types of rewards and punishments (responding in a positive fashion in anticipation of both appetitive and aversive events) or a signed expected value signal (responding positively in anticipation of rewards and negatively in anticipation of punishments) when learning cue-outcomes associations. Using a model-based fMRI approach implementing a reinforcement learning model to compute the expected values of two types of rewards (pleasant juice, monetary gain) and two types of punishments (aversive juice, aversive picture), we found that mOFC/vmPFC activity correlated positively with the expected value of the cues, in anticipation of both rewards and punishments. This finding indicates that the mOFC/vmPFC encodes a general unsigned anticipatory value signal, regardless of reinforcers valence (positive/negative) and types (gustatory, visual).

  15. The hippocampus and appetitive Pavlovian conditioning: effects of excitotoxic hippocampal lesions on conditioned locomotor activity and autoshaping.

    Science.gov (United States)

    Ito, Rutsuko; Everitt, Barry J; Robbins, Trevor W

    2005-01-01

    The hippocampus (HPC) is known to be critically involved in the formation of associations between contextual/spatial stimuli and behaviorally significant events, playing a pivotal role in learning and memory. However, increasing evidence indicates that the HPC is also essential for more basic motivational processes. The amygdala, by contrast, is important for learning about the motivational significance of discrete cues. This study investigated the effects of excitotoxic lesions of the rat HPC and the basolateral amygdala (BLA) on the acquisition of a number of appetitive behaviors known to be dependent on the formation of Pavlovian associations between a reward (food) and discrete stimuli or contexts: (1) conditioned/anticipatory locomotor activity to food delivered in a specific context and (2) autoshaping, where rats learn to show conditioned discriminated approach to a discrete visual CS+. While BLA lesions had minimal effects on conditioned locomotor activity, hippocampal lesions facilitated the development of both conditioned activity to food and autoshaping behavior, suggesting that hippocampal lesions may have increased the incentive motivational properties of food and associated conditioned stimuli, consistent with the hypothesis that the HPC is involved in inhibitory processes in appetitive conditioning.

  16. 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

  17. 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.

  18. Measurement and Analysis of Olfactory Responses with the Aim of Establishing an Objective Diagnostic Method for Central Olfactory Disorders

    Science.gov (United States)

    Uno, Tominori; Wang, Li-Qun; Miwakeichi, Fumikazu; Tonoike, Mitsuo; Kaneda, Teruo

    In order to establish a new diagnostic method for central olfactory disorders and to identify objective indicators, we measured and analyzed brain activities in the parahippocampal gyrus and uncus, region of responsibility for central olfactory disorders. The relationship between olfactory stimulation and brain response at region of responsibility can be examined in terms of fitted responses (FR). FR in these regions may be individual indicators of changes in brain olfactory responses. In the present study, in order to non-invasively and objectively measure olfactory responses, an odor oddball task was conducted on four healthy volunteers using functional magnetic resonance imaging (fMRI) and a odorant stimulator with blast-method. The results showed favorable FR and activation in the parahippocampal gyrus or uncus in all subjects. In some subjects, both the parahippocampal gyrus and uncus were activated. Furthermore, activation was also confirmed in the cingulate gyrus, middle frontal gyrus, precentral gyrus, postcentral gyrus, superior temporal gyrus and insula. The hippocampus and uncus are known to be involved in the olfactory disorders associated with early-stage Alzheimer's disease and other olfactory disorders. In the future, it will be necessary to further develop the present measurement and analysis method to clarify the relationship between central olfactory disorders and brain activities and establish objective indicators that are useful for diagnosis.

  19. Olfactory ensheathing glia are required for embryonic olfactory axon targeting and the migration of gonadotropin-releasing hormone neurons

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    Perrine Barraud

    2013-06-01

    Kallmann's syndrome is caused by the failure of olfactory axons and gonadotropin-releasing hormone (GnRH neurons to enter the embryonic forebrain, resulting in anosmia and sterility. Sox10 mutations have been associated with Kallmann's syndrome phenotypes, but their effect on olfactory system development is unknown. We recently showed that Sox10 is expressed by neural crest-derived olfactory ensheathing cells (OECs. Here, we demonstrate that in homozygous Sox10lacZ/lacZ mouse embryos, OEC differentiation is disrupted; olfactory axons accumulate in the ventromedial olfactory nerve layer and fewer olfactory receptor neurons express the maturation marker OMP (most likely owing to the failure of axonal targeting. Furthermore, GnRH neurons clump together in the periphery and a smaller proportion enters the forebrain. Our data suggest that human Sox10 mutations cause Kallmann's syndrome by disrupting the differentiation of OECs, which promote embryonic olfactory axon targeting and hence olfactory receptor neuron maturation, and GnRH neuron migration to the forebrain.

  20. Caste- and sex-specific adaptations within the olfactory pathway in the brain of the ant Camponotus floridanus.

    Science.gov (United States)

    Zube, Christina; Rössler, Wolfgang

    2008-11-01

    Olfaction plays a key role in mediating ant behavior, and ant societies are characterized by caste- and sex-specific division of labor. We propose that caste- and sex-specific adaptations in the olfactory pathway promote differences in olfactory behavior. This study compares olfactory centers in the brain of large (major) workers, small (minor) workers, virgin queens, and males of the carpenter ant Camponotus floridanus. The number of glomeruli in the antennal lobe was similar in the female castes, although the glomerular volumes differed. Males had approximately 45% fewer glomeruli compared to females (approximately 258 and approximately 434) and one antennal sensory tract was absent. A dual output pathway to the mushroom bodies was present in males. In contrast to females, however, the number of glomeruli connected to the medial antennocerebral tract was substantially smaller than those associated with the lateral tract. All glomeruli in the male antennal lobe contained serotonergic processes, whereas in the female castes glomeruli in the large tract six cluster lacked serotonergic innervations. We conclude that differences in general glomerular organization are subtle among the female castes, but sex-specific differences in the number, connectivity and neuromodulatory innervation of glomeruli are substantial and likely to underlie differences in olfactory processing and learning.

  1. The evaluation of olfactory function in individuals with chronic halitosis.

    Science.gov (United States)

    Altundag, Aytug; Cayonu, Melih; Kayabasoglu, Gurkan; Salihoglu, Murat; Tekeli, Hakan; Cayonu, Sibel; Akpinar, Meltem Esen; Hummel, Thomas

    2015-01-01

    Halitosis and olfactory dysfunction may disrupt an individual's quality of life remarkably. One may ask whether halitosis has effects on olfactory functions or not? Thus, the aim of this study was to evaluate the olfactory abilities of subjects with chronic halitosis evaluated using the measurements of volatile sulfur compounds. This study was carried out in 77 subjects, with a mean age of 40.1±13.3 years, ranging from 18 to 65 years. Forty-three participants were diagnosed as halitosis according to the gas chromatography results and constituted the halitosis group. Also, a control group was created from individuals without a complaint of halitosis and also who had normal values for volatile sulfur compounds. Each subject's orthonasal olfactory and retronasal olfactory functions were assessed using "Sniffin' Sticks" and retronasal olfactory testing. The results showed that odor threshold scores were lower in participants with halitosis compared with controls. Also, hyposmia was seen more common in the halitosis group than in controls. Moreover, a significant negative correlation was found between odor threshold scores and volatile sulfur compounds levels, particularly with hydrogen sulfide and dimethyl sulfide levels. The results suggest that the chronic presence of volatile sulfur compounds may have a negative effect on olfactory function.

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

    Directory of Open Access Journals (Sweden)

    Fomina Alla F

    2008-09-01

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

  3. The neurokinin 1 receptor antagonist, ezlopitant, reduces appetitive responding for sucrose and ethanol.

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    Pia Steensland

    Full Text Available BACKGROUND: The current obesity epidemic is thought to be partly driven by over-consumption of sugar-sweetened diets and soft drinks. Loss-of-control over eating and addiction to drugs of abuse share overlapping brain mechanisms including changes in motivational drive, such that stimuli that are often no longer 'liked' are still intensely 'wanted' [7], . The neurokinin 1 (NK1 receptor system has been implicated in both learned appetitive behaviors and addiction to alcohol and opioids; however, its role in natural reward seeking remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: We sought to determine whether the NK1-receptor system plays a role in the reinforcing properties of sucrose using a novel selective and clinically safe NK1-receptor antagonist, ezlopitant (CJ-11,974, in three animal models of sucrose consumption and seeking. Furthermore, we compared the effect of ezlopitant on ethanol consumption and seeking in rodents. The NK1-receptor antagonist, ezlopitant decreased appetitive responding for sucrose more potently than for ethanol using an operant self-administration protocol without affecting general locomotor activity. To further evaluate the selectivity of the NK1-receptor antagonist in decreasing consumption of sweetened solutions, we compared the effects of ezlopitant on water, saccharin-, and sodium chloride (NaCl solution consumption. Ezlopitant decreased intake of saccharin but had no effect on water or salty solution consumption. CONCLUSIONS/SIGNIFICANCE: The present study indicates that the NK1-receptor may be a part of a common pathway regulating the self-administration, motivational and reinforcing aspects of sweetened solutions, regardless of caloric value, and those of substances of abuse. Additionally, these results indicate that the NK1-receptor system may serve as a therapeutic target for obesity induced by over-consumption of natural reinforcers.

  4. Cellular basis for the olfactory response to nicotine.

    Science.gov (United States)

    Bryant, Bruce; Xu, Jiang; Audige, Valery; Lischka, Fritz W; Rawson, Nancy E

    2010-03-17

    Smokers regulate their smoking behavior on the basis of sensory stimuli independently of the pharmacological effects of nicotine (Rose J. E., et al. (1993) Pharmacol., Biochem. Behav.44 (4), 891-900). A better understanding of sensory mechanisms underlying smoking behavior may help to develop more effective smoking alternatives. Olfactory stimulation by nicotine makes up a considerable part of the flavor of tobacco smoke, yet our understanding of the cellular mechanisms responsible for olfactory detection of nicotine remains incomplete. We used biophysical methods to characterize the nicotine sensitivity and response mechanisms of neurons from olfactory epithelium. In view of substantial differences in the olfactory receptor repertoire between rodent and human (Mombaerts P. (1999) Annu. Rev. Neurosci.22, 487-509), we studied biopsied human olfactory sensory neurons (OSNs), cultured human olfactory cells (Gomez G., et al. (2000) J. Neurosci. Res.62 (5), 737-749), and rat olfactory neurons. Rat and human OSNs responded to S(-)-nicotine with a concentration dependent influx of calcium and activation of adenylate cyclase. Some rat OSNs displayed some stereoselectivity, with neurons responding to either enantiomer alone or to both. Freshly biopsied and primary cultured human olfactory neurons were less stereoselective. Nicotinic cholinergic antagonists had no effect on the responses of rat or human OSNs to nicotine. Patch clamp recording of rat OSNs revealed a nicotine-activated, calcium-sensitive nonspecific cation channel. These results indicate that nicotine activates a canonical olfactory receptor pathway rather than nicotinic cholinergic receptors on OSNs. Further, because the nicotine-sensitive mechanisms of rodents appear generally similar to those of humans, this animal model is an appropriate one for studies of nicotine sensation.

  5. Self-Reported Appetite and Intake Adequacy In Patients With Non-dialysis Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Maria Chan

    2012-06-01

    The positive predictive value (95%CI of appetite rating for energy and protein were 0.37 (0.32–0.41 and 0.90 (0.86–0.93 respectively. In conclusion, while self-reported appetite scores were useful in ranking energy and protein intakes, subjective reporting of good appetite was associated with adequate protein but not energy intake. Report of a good appetite does not always mean adequate intake in non-dialysis ESKD patients with high symptom burden.

  6. Predictors of posttraumatic stress and appetitive aggression in active soldiers and former combatants.

    Science.gov (United States)

    Nandi, Corina; Crombach, Anselm; Bambonye, Manassé; Elbert, Thomas; Weierstall, Roland

    2015-01-01

    During the period between 1993 and 2005, the people of Burundi were trapped within a violent civil war. In post-conflict regions, symptoms of posttraumatic stress disorder (PTSD) were found to be widespread. At the same time, combatants often reported having perceived committing violence as exciting and appealing, an experience referred to as appetitive aggression. Both of these phenomena hamper the building of a functional and peaceful society. This study aims to investigate the factors that are associated with the level of PTSD and appetitive aggression in former and still active combatants. Semi-structured interviews were conducted with 948 male Burundians: 556 active soldiers and 392 ex-combatants. PTSD symptom severity was assessed using the PTSD Symptom Scale Interview, while appetitive aggression was assessed using the Appetitive Aggression Scale. Linear regression analyses revealed that the number of traumatic events, childhood maltreatment, and their interaction predicted PTSD symptom severity, whereas self-committed violence did not. The number of traumatic events and self-committed violence were associated with appetitive aggression. Childhood maltreatment alone was not associated with appetitive aggression; however, its interaction with self-committed violence did predict appetitive aggression. When controlling for predictors, ex-combatants reported a higher degree of PTSD symptomatology, whereas active soldiers reported a higher degree of appetitive aggression. We conclude that childhood maltreatment is an additional, significant risk factor that exacerbates the psychological consequences of violent conflicts. Self-committed violence may not necessarily engender trauma-related disorders, but is highly related to appetitive aggression.

  7. Do ketogenic diets really suppress appetite? A systematic review and meta-analysis.

    Science.gov (United States)

    Gibson, A A; Seimon, R V; Lee, C M Y; Ayre, J; Franklin, J; Markovic, T P; Caterson, I D; Sainsbury, A

    2015-01-01

    Very-low-energy diets (VLEDs) and ketogenic low-carbohydrate diets (KLCDs) are two dietary strategies that have been associated with a suppression of appetite. However, the results of clinical trials investigating the effect of ketogenic diets on appetite are inconsistent. To evaluate quantitatively the effect of ketogenic diets on subjective appetite ratings, we conducted a systematic literature search and meta-analysis of studies that assessed appetite with visual analogue scales before (in energy balance) and during (while in ketosis) adherence to VLED or KLCD. Individuals were less hungry and exhibited greater fullness/satiety while adhering to VLED, and individuals adhering to KLCD were less hungry and had a reduced desire to eat. Although these absolute changes in appetite were small, they occurred within the context of energy restriction, which is known to increase appetite in obese people. Thus, the clinical benefit of a ketogenic diet is in preventing an increase in appetite, despite weight loss, although individuals may indeed feel slightly less hungry (or more full or satisfied). Ketosis appears to provide a plausible explanation for this suppression of appetite. Future studies should investigate the minimum level of ketosis required to achieve appetite suppression during ketogenic weight loss diets, as this could enable inclusion of a greater variety of healthy carbohydrate-containing foods into the diet.

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

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2014-01-01

    Full Text Available 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 worldwide. Here we gathered two cases from Department of Neurosurgery in Beijing Tiantan Hospital across two years collection.

  9. Face detection for interactive tabletop viewscreen system using olfactory display

    Science.gov (United States)

    Sakamoto, Kunio; Kanazawa, Fumihiro

    2009-10-01

    An olfactory display is a device that delivers smells to the nose. It provides us with special effects, for example to emit smell as if you were there or to give a trigger for reminding us of memories. The authors have developed a tabletop display system connected with the olfactory display. For delivering a flavor to user's nose, the system needs to recognition and measure positions of user's face and nose. In this paper, the authors describe an olfactory display which enables to detect the nose position for an effective delivery.

  10. SNP genotypes of olfactory receptor genes associated with olfactory ability in German Shepherd dogs.

    Science.gov (United States)

    Yang, M; Geng, G-J; Zhang, W; Cui, L; Zhang, H-X; Zheng, J-L

    2016-04-01

    To find out the relationship between SNP genotypes of canine olfactory receptor genes and olfactory ability, 28 males and 20 females from German Shepherd dogs in police service were scored by odor detection tests and analyzed using the Beckman GenomeLab SNPstream. The representative 22 SNP loci from the exonic regions of 12 olfactory receptor genes were investigated, and three kinds of odor (human, ice drug and trinitrotoluene) were detected. The results showed that the SNP genotypes at the OR10H1-like:c.632C>T, OR10H1-like:c.770A>T, OR2K2-like:c.518G>A, OR4C11-like:c.511T>G and OR4C11-like:c.692G>A loci had a statistically significant effect on the scenting abilities (P dogs (P T, OR10H1-like:c.770A>T, OR4C11-like:c.511T>G and OR4C11-like:c.692G>A (P dogs with genotype CC at the OR10H1-like:c.632C>T, genotype AA at the OR10H1-like:c.770A>T, genotype TT at the OR4C11-like:c.511T>G and genotype GG at the OR4C11-like:c.692G>A loci did better at detecting the ice drug. We concluded that there was linkage between certain SNP genotypes and the olfactory ability of dogs and that SNP genotypes might be useful in determining dogs' scenting potential.

  11. Appetite control and energy balance: impact of exercise.

    Science.gov (United States)

    Blundell, J E; Gibbons, C; Caudwell, P; Finlayson, G; Hopkins, M

    2015-02-01

    Exercise is widely regarded as one of the most valuable components of behaviour that can influence body weight and therefore help in the prevention and management of obesity. Indeed, long-term controlled trials show a clear dose-related effect of exercise on body weight. However, there is a suspicion, particularly fuelled by media reports, that exercise serves to increase hunger and drive up food intake thereby nullifying the energy expended through activity. Not everyone performing regular exercise will lose weight and several investigations have demonstrated a huge individual variability in the response to exercise regimes. What accounts for this heterogeneous response? First, exercise (or physical activity) through the expenditure of energy will influence the energy balance equation with the potential to generate an energy deficit. However, energy expenditure also influences the control of appetite (i.e. the physiological and psychological regulatory processes underpinning feeding) and energy intake. This dynamic interaction means that the prediction of a resultant shift in energy balance, and therefore weight change, will be complicated. In changing energy intake, exercise will impact on the biological mechanisms controlling appetite. It is becoming recognized that the major influences on the expression of appetite arise from fat-free mass and fat mass, resting metabolic rate, gastric adjustment to ingested food, changes in episodic peptides including insulin, ghrelin, cholecystokinin, glucagon-like peptide-1 and tyrosine-tyrosine, as well as tonic peptides such as leptin. Moreover, there is evidence that exercise will influence all of these components that, in turn, will influence the drive to eat through the modulation of hunger (a conscious sensation reflecting a mental urge to eat) and adjustments in postprandial satiety via an interaction with food composition. The specific actions of exercise on each physiological component will vary in strength from

  12. Ghrelin plasma levels and appetite in peritoneal dialysis patients.

    Science.gov (United States)

    Aguilera, Abelardo; Cirugeda, Antonio; Amair, Ruth; Sansone, Gabriela; Alegre, Laura; Codoceo, Rosa; Bajo, M Auxiliadora; del Peso, Gloria; Díez, Juan J; Sánchez-Tomero, José A; Selgas, Rafael

    2004-01-01

    Anorexia-associated malnutrition is a severe complication that increases mortality in peritoneal dialysis (PD) patients. Ghrelin is a recently-discovered orexigenic hormone with actions in brain and stomach. We analyzed, in 42 PD patients, the possible relationship between ghrelin and appetite regulation with regard to other orexigens [neuropeptide Y (NPY), NO3] and anorexigens [cholecystokinin (CCK), leptin, glucose-dependent insulinotropic peptide (GIP), tumor necrosis factor alpha (TNFalpha)]. All orexigens and anorexigens were determined in plasma. Eating motivation was evaluated using a visual analog scale (VAS). The patients were divided into three groups: those with anorexia (n = 12), those with obesity associated with high intake (n = 12), and those with no eating behavior disorders (n = 18). A control group of 10 healthy volunteers was also evaluated. Mean plasma levels of ghrelin were high (3618.6 +/- 1533 mg/mL), with 36 patients showing values above the normal range (anorexia had lower ghrelin and NPY levels and higher peptide-C, CCK, interleukin-1 (IL-1), TNFalpha, and GIP levels than did the other patients. Patients with anorexia also had an early satiety score and low desire and pleasure in eating on the VAS and diet survey. We observed significant positive linear correlations between ghrelin and albumin (r = 0.43, p anorexia show relatively lower ghrelin plasma levels than the levels seen in obese patients or in patients with normal appetite. The role of ghrelin in appetite modulation is altered in uremic PD patients, and that alteration is possibly associated with disorders in insulin and growth hormone metabolism.

  13. 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.

  14. Intermittency coding in the primary olfactory system: a neural substrate for olfactory scene analysis.

    Science.gov (United States)

    Park, Il Memming; Bobkov, Yuriy V; Ache, Barry W; Príncipe, José C

    2014-01-15

    The spatial and temporal characteristics of the visual and acoustic sensory input are indispensable attributes for animals to perform scene analysis. In contrast, research in olfaction has focused almost exclusively on how the nervous system analyzes the quality and quantity of the sensory signal and largely ignored the spatiotemporal dimension especially in longer time scales. Yet, detailed analyses of the turbulent, intermittent structure of water- and air-borne odor plumes strongly suggest that spatio-temporal information in longer time scales can provide major cues for olfactory scene analysis for animals. We show that a bursting subset of primary olfactory receptor neurons (bORNs) in lobster has the unexpected capacity to encode the temporal properties of intermittent odor signals. Each bORN is tuned to a specific range of stimulus intervals, and collectively bORNs can instantaneously encode a wide spectrum of intermittencies. Our theory argues for the existence of a novel peripheral mechanism for encoding the temporal pattern of odor that potentially serves as a neural substrate for olfactory scene analysis.

  15. Effects of RYGB on energy expenditure, appetite and glycemic control

    DEFF Research Database (Denmark)

    Schmidt, Julie Berg; Pedersen, Susie Dawn; Gregersen, Nikolaj Ture

    2016-01-01

    Objectives: Increased energy expenditure (EE) has been proposed an important mechanism for weight loss following Roux-en-Y gastric bypass (RYGB). However, this has never been investigated in a controlled setting independent of changes in energy balance. Likewise, only few studies have investigated...... different between the groups, but RYGB operated had lower fasting glucose (Pafter RYGB. More likely, RYGB promotes weight loss by reducing appetite, partly mediated...... by changes in gastrointestinal hormone secretion. Furthermore, we found that the early changes in glycaemic control after RYGB is to a large extent mediated by caloric restriction....

  16. Reappraising social insect behavior through aversive responsiveness and learning.

    Directory of Open Access Journals (Sweden)

    Edith Roussel

    Full Text Available BACKGROUND: The success of social insects can be in part attributed to their division of labor, which has been explained by a response threshold model. This model posits that individuals differ in their response thresholds to task-associated stimuli, so that individuals with lower thresholds specialize in this task. This model is at odds with findings on honeybee behavior as nectar and pollen foragers exhibit different responsiveness to sucrose, with nectar foragers having higher response thresholds to sucrose concentration. Moreover, it has been suggested that sucrose responsiveness correlates with responsiveness to most if not all other stimuli. If this is the case, explaining task specialization and the origins of division of labor on the basis of differences in response thresholds is difficult. METHODOLOGY: To compare responsiveness to stimuli presenting clear-cut differences in hedonic value and behavioral contexts, we measured appetitive and aversive responsiveness in the same bees in the laboratory. We quantified proboscis extension responses to increasing sucrose concentrations and sting extension responses to electric shocks of increasing voltage. We analyzed the relationship between aversive responsiveness and aversive olfactory conditioning of the sting extension reflex, and determined how this relationship relates to division of labor. PRINCIPAL FINDINGS: Sucrose and shock responsiveness measured in the same bees did not correlate, thus suggesting that they correspond to independent behavioral syndromes, a foraging and a defensive one. Bees which were more responsive to shock learned and memorized better aversive associations. Finally, guards were less responsive than nectar foragers to electric shocks, exhibiting higher tolerance to low voltage shocks. Consequently, foragers, which are more sensitive, were the ones learning and memorizing better in aversive conditioning. CONCLUSIONS: Our results constitute the first integrative

  17. Pavlovian conditioning of emotional responses to olfactory and contextual stimuli: a potential model for the development and expression of chemical intolerance.

    Science.gov (United States)

    Otto, T; Giardino, N D

    2001-03-01

    Chemical intolerance (CI) in humans is a poorly understood phenomenon of uncertain etiology, seemingly influenced by multiple factors both within and between affected individuals. Several authors have suggested that the development of CI in some individuals may be due, at least in part, to Pavlovian conditioning processes in which the expression of overt symptoms to certain substances reflects classically conditioned responses to previously neutral olfactory and contextual stimuli. In this paper, we describe the potential relationship between olfactory and contextual conditioning in experimental animals and the development and expression of CI in humans. Furthermore, as significant advances have been made in delineating the brain areas that underlie these learned responses, we also review recent research on the contributions of the amygdala and perirhinal cortical region to olfactory and contextual fear conditioning.

  18. Nogo-A expression in injured spinal cord following human olfactory mucosa-derived olfactory ensheathing cells transplantation

    Institute of Scientific and Technical Information of China (English)

    Bin Wang; Qiang Li; Xijing He; Weixiong Wang

    2011-01-01

    Transplantation of olfactory bulb-derived olfactory ensheathing cells (OECs) promotes motor functional recovery in rats with acute spinal cord injury, possibly by Nogo-A expression changes at the injury site. The present study transplanted OECs derived from the olfactory mucosa (OM) of rats. OM-derived OEC (OM-OEC) transplantation significantly reduced the increase of Nogo-A protein and mRNA expression caused by spinal cord injury, supporting the hypothesis that OM-OECs improve spinal cord regeneration by reducing Nogo-A expression.

  19. 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.

  20. Fault tolerant architecture for artificial olfactory system

    Science.gov (United States)

    Lotfivand, Nasser; Nizar Hamidon, Mohd; Abdolzadeh, Vida

    2015-05-01

    In this paper, to cover and mask the faults that occur in the sensing unit of an artificial olfactory system, a novel architecture is offered. The proposed architecture is able to tolerate failures in the sensors of the array and the faults that occur are masked. The proposed architecture for extracting the correct results from the output of the sensors can provide the quality of service for generated data from the sensor array. The results of various evaluations and analysis proved that the proposed architecture has acceptable performance in comparison with the classic form of the sensor array in gas identification. According to the results, achieving a high odor discrimination based on the suggested architecture is possible.

  1. Exercise-Trained Men and Women: Role of Exercise and Diet on Appetite and Energy Intake

    Science.gov (United States)

    Howe, Stephanie M.; Hand, Taryn M.; Manore, Melinda M.

    2014-01-01

    The regulation of appetite and energy intake is influenced by numerous hormonal and neural signals, including feedback from changes in diet and exercise. Exercise can suppress subjective appetite ratings, subsequent energy intake, and alter appetite-regulating hormones, including ghrelin, peptide YY, and glucagon-like peptide 1(GLP-1) for a period of time post-exercise. Discrepancies in the degree of appetite suppression with exercise may be dependent on subject characteristics (e.g., body fatness, fitness level, age or sex) and exercise duration, intensity, type and mode. Following an acute bout of exercise, exercise-trained males experience appetite suppression, while data in exercise-trained women are limited and equivocal. Diet can also impact appetite, with low-energy dense diets eliciting a greater sense of fullness at a lower energy intake. To date, little research has examined the combined interaction of exercise and diet on appetite and energy intake. This review focuses on exercise-trained men and women and examines the impact of exercise on hormonal regulation of appetite, post-exercise energy intake, and subjective and objective measurements of appetite. The impact that low-energy dense diets have on appetite and energy intake are also addressed. Finally, the combined effects of high-intensity exercise and low-energy dense diets are examined. This research is in exercise-trained women who are often concerned with weight and body image issues and consume low-energy dense foods to keep energy intakes low. Unfortunately, these low-energy intakes can have negative health consequences when combined with high-levels of exercise. More research is needed examining the combined effect of diet and exercise on appetite regulation in fit, exercise-trained individuals. PMID:25389897

  2. Are increased weight and appetite useful indicators of depression in children and adolescents?

    Science.gov (United States)

    Cole, David A; Cho, Sun-Joo; Martin, Nina C; Youngstrom, Eric A; March, John S; Findling, Robert L; Compas, Bruce E; Goodyer, Ian M; Rohde, Paul; Weissman, Myrna; Essex, Marilyn J; Hyde, Janet S; Curry, John F; Forehand, Rex; Slattery, Marcia J; Felton, Julia W; Maxwell, Melissa A

    2012-11-01

    During childhood and adolescence, physiological, psychological, and behavioral processes strongly promote weight gain and increased appetite while also inhibiting weight loss and decreased appetite. The Diagnostic and Statistical Manual-IV (DSM-IV) treats both weight-gain/increased-appetite and weight-loss/decreased-appetite as symptoms of major depression during these developmental periods, despite the fact that one complements typical development and the other opposes it. To disentangle the developmental versus pathological correlates of weight and appetite disturbance in younger age groups, the current study examined symptoms of depression in an aggregated sample of 2307 children and adolescents, 47.25% of whom met criteria for major depressive disorder. A multigroup, multidimensional item response theory model generated three key results. First, weight loss and decreased appetite loaded strongly onto a general depression dimension; in contrast, weight gain and increased appetite did not. Instead, weight gain and increased appetite loaded onto a separate dimension that did not correlate strongly with general depression. Second, inclusion or exclusion of weight gain and increased appetite affected neither the nature of the general depression dimension nor the fidelity of major depressive disorder diagnosis. Third, the general depression dimension and the weight-gain/increased-appetite dimension showed different patterns across age and gender. In child and adolescent populations, these results call into question the utility of weight gain and increased appetite as indicators of depression. This has serious implications for the diagnostic criteria of depression in children and adolescents. These findings inform a revision of the DSM, with implications for the diagnosis of depression in this age group and for research on depression.

  3. Associations of children's appetitive traits with weight and dietary behaviours in the context of general parenting.

    Directory of Open Access Journals (Sweden)

    Gerda Rodenburg

    Full Text Available BACKGROUND: Individual variations in child weight can be explained by genetic and behavioural susceptibility to obesity. Behavioural susceptibility can be expressed in appetite-related traits, e.g. food responsiveness. Research into such behavioural factors is important, as it can provide starting points for (preventive interventions. OBJECTIVES: To examine associations of children's appetitive traits with weight and with fruit, snack and sugar-sweetened beverage intake, and to examine whether parenting style interacts with appetite in determining child weight/intake. METHODS: Data were used from 1275 children participating in the INPACT study in 2009-2010, with a mean age of 9 years in 2009. Their height and weight were measured to calculate body mass index (BMI. Parents completed a questionnaire to measure children's appetitive traits, children's dietary intake and parenting style. Child BMI z-scores, fruit, snack and sugar-sweetened beverage intake were regressed on appetitive traits. Moderation by parenting style was tested by adding interaction terms to the regression analyses. RESULTS: Food-approaching appetitive traits were positively, and food-avoidant appetitive traits were negatively related to child BMI z-scores and to child fruit intake. There were no or less consistent associations for snack and sugar-sweetened beverage intake. Authoritative parenting voided the negative association between food fussiness and fruit intake, while neglecting parenting strengthened the positive association between food-approaching appetitive traits and weight. CONCLUSIONS: Early assessment of appetitive traits could be used to identify children at risk for overweight. As parenting style can moderate the associations between appetitive traits and weight/intake in a favourable way, parents are a promising target group for preventive interventions aimed at influencing the effect of appetitive traits on children.

  4. Exercise-Trained Men and Women: Role of Exercise and Diet on Appetite and Energy Intake

    Directory of Open Access Journals (Sweden)

    Stephanie M. Howe

    2014-11-01

    Full Text Available The regulation of appetite and energy intake is influenced by numerous hormonal and neural signals, including feedback from changes in diet and exercise. Exercise can suppress subjective appetite ratings, subsequent energy intake, and alter appetite-regulating hormones, including ghrelin, peptide YY, and glucagon-like peptide 1(GLP-1 for a period of time post-exercise. Discrepancies in the degree of appetite suppression with exercise may be dependent on subject characteristics (e.g., body fatness, fitness level, age or sex and exercise duration, intensity, type and mode. Following an acute bout of exercise, exercise-trained males experience appetite suppression, while data in exercise-trained women are limited and equivocal. Diet can also impact appetite, with low-energy dense diets eliciting a greater sense of fullness at a lower energy intake. To date, little research has examined the combined interaction of exercise and diet on appetite and energy intake. This review focuses on exercise-trained men and women and examines the impact of exercise on hormonal regulation of appetite, post-exercise energy intake, and subjective and objective measurements of appetite. The impact that low-energy dense diets have on appetite and energy intake are also addressed. Finally, the combined effects of high-intensity exercise and low-energy dense diets are examined. This research is in exercise-trained women who are often concerned with weight and body image issues and consume low-energy dense foods to keep energy intakes low. Unfortunately, these low-energy intakes can have negative health consequences when combined with high-levels of exercise. More research is needed examining the combined effect of diet and exercise on appetite regulation in fit, exercise-trained individuals.

  5. Exercise-trained men and women: role of exercise and diet on appetite and energy intake.

    Science.gov (United States)

    Howe, Stephanie M; Hand, Taryn M; Manore, Melinda M

    2014-11-10

    The regulation of appetite and energy intake is influenced by numerous hormonal and neural signals, including feedback from changes in diet and exercise. Exercise can suppress subjective appetite ratings, subsequent energy intake, and alter appetite-regulating hormones, including ghrelin, peptide YY, and glucagon-like peptide 1(GLP-1) for a period of time post-exercise. Discrepancies in the degree of appetite suppression with exercise may be dependent on subject characteristics (e.g., body fatness, fitness level, age or sex) and exercise duration, intensity, type and mode. Following an acute bout of exercise, exercise-trained males experience appetite suppression, while data in exercise-trained women are limited and equivocal. Diet can also impact appetite, with low-energy dense diets eliciting a greater sense of fullness at a lower energy intake. To date, little research has examined the combined interaction of exercise and diet on appetite and energy intake. This review focuses on exercise-trained men and women and examines the impact of exercise on hormonal regulation of appetite, post-exercise energy intake, and subjective and objective measurements of appetite. The impact that low-energy dense diets have on appetite and energy intake are also addressed. Finally, the combined effects of high-intensity exercise and low-energy dense diets are examined. This research is in exercise-trained women who are often concerned with weight and body image issues and consume low-energy dense foods to keep energy intakes low. Unfortunately, these low-energy intakes can have negative health consequences when combined with high-levels of exercise. More research is needed examining the combined effect of diet and exercise on appetite regulation in fit, exercise-trained individuals.

  6. Inhibition by somatostatin interneurons in olfactory cortex

    Directory of Open Access Journals (Sweden)

    Adam M Large

    2016-08-01

    Full Text Available Inhibitory circuitry plays an integral cortical network activity. The development of transgenic mouse lines targeting unique interneuron classes has significantly advanced our understanding of the functional roles of specific inhibitory circuits in neocortical sensory processing. In contrast, considerably less is known about the circuitry and function of interneuron classes in piriform cortex, a paleocortex responsible for olfactory processing. In this study, we sought to utilize transgenic technology to investigate inhibition mediated by somatostatin (SST interneurons onto pyramidal cells, parvalbumin (PV interneurons and other interneuron classes. As a first step, we characterized the anatomical distributions and intrinsic properties of SST and PV interneurons in four transgenic lines (SST-cre, GIN, PV-cre and G42 that are commonly interbred to investigate inhibitory connectivity. Surprisingly, the distributions SST and PV cell subtypes targeted in the GIN and G42 lines were sparse in piriform cortex compared to neocortex. Moreover, two-thirds of interneurons recorded in the SST-cre line had electrophysiological properties similar to fast spiking (FS interneurons rather than regular (RS or low threshold spiking (LTS phenotypes. Nonetheless, like neocortex, we find that SST-cells broadly inhibit a number of unidentified interneuron classes including putatively identified PV cells and surprisingly, other SST cells. We also confirm that SST-cells inhibit pyramidal cell dendrites and thus, influence dendritic integration of afferent and recurrent inputs to the piriform cortex. Altogether, our findings suggest that somatostatin interneurons play an important role in regulating both excitation and the global inhibitory network during olfactory processing.

  7. Widespread ectopic expression of olfactory receptor genes

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    Yanai Itai

    2006-05-01

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

  8. Neural correlates of olfactory processing in congenital blindness

    DEFF Research Database (Denmark)

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

    2011-01-01

    Adaptive neuroplastic changes have been well documented in congenitally blind individuals for the processing of tactile and auditory information. By contrast, very few studies have investigated olfactory processing in the absence of vision. There is ample evidence that the olfactory system...... is 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....... The stronger recruitment of the occipital cortex during odor detection demonstrates a preferential access of olfactory stimuli to this area when vision is lacking from birth. This finding expands current knowledge about the supramodal function of the visually deprived occipital cortex in congenital blindness...

  9. 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. © The Author(s) 2016.

  10. Organization of olfactory centres in the malaria mosquito Anopheles gambiae

    Science.gov (United States)

    Riabinina, Olena; Task, Darya; Marr, Elizabeth; Lin, Chun-Chieh; Alford, Robert; O'Brochta, David A.; Potter, Christopher J.

    2016-01-01

    Mosquitoes are vectors for multiple infectious human diseases and use a variety of sensory cues (olfactory, temperature, humidity and visual) to locate a human host. A comprehensive understanding of the circuitry underlying sensory signalling in the mosquito brain is lacking. Here we used the Q-system of binary gene expression to develop transgenic lines of Anopheles gambiae in which olfactory receptor neurons expressing the odorant receptor co-receptor (Orco) gene are labelled with GFP. These neurons project from the antennae and maxillary palps to the antennal lobe (AL) and from the labella on the proboscis to the suboesophageal zone (SEZ), suggesting integration of olfactory and gustatory signals occurs in this brain region. We present detailed anatomical maps of olfactory innervations in the AL and the SEZ, identifying glomeruli that may respond to human body odours or carbon dioxide. Our results pave the way for anatomical and functional neurogenetic studies of sensory processing in mosquitoes. PMID:27694947

  11. Calcium Signaling in Mitral Cell Dendrites of Olfactory Bulbs of Neonatal Rats and Mice during Olfactory Nerve Stimulation and Beta-Adrenoceptor Activation

    Science.gov (United States)

    Yuan, Qi; Mutoh, Hiroki; Debarbieux, Franck; Knopfel, Thomas

    2004-01-01

    Synapses formed by the olfactory nerve (ON) provide the source of excitatory synaptic input onto mitral cells (MC) in the olfactory bulb. These synapses, which relay odor-specific inputs, are confined to the distally tufted single primary dendrites of MCs, the first stage of central olfactory processing. Beta-adrenergic modulation of electrical…

  12. [Effect of acupuncture therapy on appetite of obesity patients].

    Science.gov (United States)

    Yao, Hong; Chen, Jian-Xiong; Zhang, Zi-Qian; Pan, Yu; Zheng, Jie; Tong, Juan

    2012-12-01

    To observe the effect of acupuncture intervention on the appetite of obesity patients. A total of 118 obesity patients were randomized into acupuncture group (76 cases, treated by true acupuncture needles) and placebo group (42 cases, treated by placebo acupuncture needles) using single-blind method. All the patients of the two groups were ordered to control their diet during the treatment. The acupoints around the umbilicus [Zhongwan (CV 12), Zhongji (CV 3), Daheng (SP 15), Xiawan (CV 10), Shimen (CV 5) and Tianshu (ST 25), etc.] and Liangqiu (ST 34), Zusanli (ST 36), and Yin-lingquan (SP 9) were punctured with filiform needles which were manipulated with uniform reducing and reinforcing method for a while tijl "Deqi" and retained for 30 min. The treatment was conducted once every other day, 12 times altogether. Body mass index (BMI), and visual analogue scale (VAS) scores of eating-desire and hunger feeling and prospective food consumption were measured before and after the treatment. The gastric fluid survival rate (GFSR) was evaluated by using ultrasound scanning. The BMI in the acupuncture group was obviously declined after the treatment in comparison with the placebo group (P acupuncture group ( P 0.05). The GFSR was obviously increased in the acupuncture group compared to the placebo group (P Acupuncture therapy can significantly decrease BMI and delay the digesting time and control the appetite in obesity patients, which may contribute to its effect in body weight reduction.

  13. Cocaine's appetite for fat and the consequences on body weight.

    Science.gov (United States)

    Billing, Lawrence; Ersche, Karen D

    2015-03-01

    For many individuals in treatment for cocaine dependence, weight gain is a substantial problem during recovery. This weight gain causes significant distress and seems to increase the risk of relapse. The mechanisms underlying cocaine's effects on weight remain elusive. It is widely assumed that this weight gain reflects a metabolic or behavioural compensatory response to the cessation of cocaine use. Here we challenge this assumption and outline potential mechanisms by which chronic cocaine use produces disturbances in the regulation of fat intake and storage, through its effects on the central and peripheral nervous systems, specifically the sympathetic nervous system. We hypothesize that the cocaine-induced alteration in fat regulation results in cocaine users developing a pronounced appetite for fatty food but keeps their fat mass low. This altered fat appetite subsequently leads to excessive weight gain when individuals enter treatment and stop using cocaine. Our aim is to shed light on the neurobiological mechanisms that may underlie the alterations in eating and fat regulation in cocaine-dependent individuals, to open up potential new avenues to support these individuals in recovery.

  14. Reference values of olfactory function for Mexico City inhabitants.

    Science.gov (United States)

    Guarneros, Marco; Hudson, Robyn; López-Palacios, Martha; Drucker-Colín, René

    2015-01-01

    Olfactory testing is useful in the differential diagnosis of age-related pathologies. To provide baseline reference values for clinical use in Mexico City we investigated the relation between olfactory capabilities and the principal population parameters of age, sex, and smoking habits in a large sample of healthy inhabitants. We applied the internationally recognized and commercially available Sniffin' Sticks test battery to 916 men and women from across the adult life span. The Sniffin' Sticks test evaluates three key aspects of olfactory function: 1) ability to detect an odor, 2) to discriminate between odors, and 3) to identify odors. We found a significant decline in olfactory function from the 5th decade of age, and that detection threshold was the most sensitive measure of this. We did not find a significant difference between men and women or between smokers and non-smokers. In confirmation of our previous studies of the negative effect of air pollution on olfactory function, Mexico City inhabitants had poorer overall performance than corresponding subjects previously tested in the neighboring but less polluted Mexican state of Tlaxcala. Although we basically confirm findings on general demographic patterns of olfactory performance from other countries, we also demonstrate the need to take into account local cultural, environmental and demographic factors in the clinical evaluation of olfactory performance of Mexico City inhabitants. The Sniffin' Sticks test battery, with some adjustment of stimuli to correspond to Mexican culture, provides an easily administered means of assessing olfactory health. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  15. 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.

  16. Synaptic clusters function as odor operators in the olfactory bulb

    OpenAIRE

    Migliore, Michele; Cavarretta, Francesco; Marasco, Addolorata; Tulumello, Eleonora; Michael L Hines; Shepherd, Gordon M.

    2015-01-01

    How the olfactory bulb organizes and processes odor inputs through fundamental operations of its microcircuits is still controversial. To reveal these operations we hypothesize that one of the key mechanisms underlying odor coding is the interaction among spatially restricted and well-defined clusters of potentiated mitral–granule cell synapses. These experimentally observed clusters selectively gate the propagation of neuronal activity within the olfactory bulb and extensively contribute to ...

  17. 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.

  18. 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 examin...... in bilateral mOFC and anterior insula. Our data provide a neurological underpinning for the reduced taste perception in congenitally olfactory impaired individuals....

  19. Role of the serotoninergic system in the sodium appetite control

    Directory of Open Access Journals (Sweden)

    Luís C. Reis

    2007-06-01

    Full Text Available The present article reviews the role of the serotoninergic system in the regulation of the sodium appetite. Data from the peripheral and icv administration of serotoninergic (5-HTergic agents showed the participation of 5-HT2/3 receptors in the modulation of sodium appetite. These observations were extended with the studies carried out after brain serotonin depletion, lesions of DRN and during blockade of 5-HT2A/2C receptors in lateral parabrachial nucleus (LPBN. Brain serotonin depletion and lesions of DRN increased the sodium appetite response, in basal conditions, after sodium depletion and hypovolemia or after beta-adrenergic stimulation as well. These observations raised the hypothesis that the suppression of ascending pathways from the DRN, possibly, 5-HTergic fibers, modifies the angiotensinergic or sodium sensing mechanisms of the subfornical organ involved in the control of the sodium appetite. 5-HTergic blockade in LPBN induced to similar results, particularly those regarded to the natriorexigenic response evoked by volume depletion or increase of the hypertonic saline ingestion induced by brain angiotensinergic stimulation. In conclusion, many evidences lead to acceptation of an integrated participation resulting of an interaction, between DRN and LPBN, for the sodium appetite control.Este artigo revisa o papel do sistema serotoninérgico no controle do apetite ao sódio. Dados derivados da administração periférica e icv de agentes serotoninérgicos demonstraram a participação de receptores 5-HT2/3 na modulação do apetite ao sódio. Estas observações foram estendidas com os estudos realizados após a depleção cerebral de serotonina, lesões do NDR e durante o bloqueio 5-HT2A/2C no núcleo parabraquial lateral (NPBL. A depleção cerebral de serotonina e as lesões do NDR aumentaram o apetite ao sódio, em condições basais, após depleção de sódio, durante a hipovolemia ou após a estimulação beta-adrenérgica. Estas

  20. Apoptotic death of olfactory sensory neurons in the adult rat.

    Science.gov (United States)

    Deckner, M L; Risling, M; Frisén, J

    1997-01-01

    Olfactory sensory neurons only live for about 1 month in most mammals. It is not fully understood whether the short life span of these neurons is due to necrotic death, or if these cells die by apoptosis. One characteristic of cells undergoing apoptotic cell death is internucleosomal DNA-fragmentation. We have used TdT-mediated dUTP-digoxigenin nick end labeling (TUNEL) to detect cells undergoing DNA-fragmentation in situ. In the intact olfactory epithelium of adult rats a subpopulation of basal immature neuronal progenitor cells, as well as mature olfactory sensory neurons, showed DNA-fragmentation. The number of TUNEL-labeled neurons increased dramatically 1.5 days after transection of the fila olfactoria and declined to control levels by Day 4 after the injury. In order to relate DNA-fragmentation to ultrastructural characteristics of apoptosis we modified the TUNEL-labeling protocol to enable studies of TUNEL-labeled cells in the electron microscope. This confirmed that TUNEL-labeled neurons showed morphological characteristics of apoptosis. The data provide evidence for apoptotic death of neurons in the adult mammalian nervous system. The turnover of olfactory sensory neurons is, at least in part, regulated by apoptosis and disruption of the contact with the olfactory bulb results in massive apoptotic death of neurons in the olfactory epithelium.

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

    Science.gov (United States)

    Grimaud, Julien

    2016-01-01

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

  2. Go contributes to olfactory reception in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Roman Gregg

    2009-01-01

    Full Text Available Abstract Background Seven-transmembrane receptors typically mediate olfactory signal transduction by coupling to G-proteins. Although insect odorant receptors have seven transmembrane domains like G-protein coupled receptors, they have an inverted membrane topology and function as ligand-gated cation channels. Consequently, the involvement of cyclic nucleotides and G proteins in insect odor reception is controversial. Since the heterotrimeric Goα subunit is expressed in Drosophila olfactory receptor neurons, we reasoned that Go acts together with insect odorant receptor cation channels to mediate odor-induced physiological responses. Results To test whether Go dependent signaling is involved in mediating olfactory responses in Drosophila, we analyzed electroantennogram and single-sensillum recording from flies that conditionally express pertussis toxin, a specific inhibitor of Go in Drosophila. Pertussis toxin expression in olfactory receptor neurons reversibly reduced the amplitude and hastened the termination of electroantennogram responses induced by ethyl acetate. The frequency of odor-induced spike firing from individual sensory neurons was also reduced by pertussis toxin. These results demonstrate that Go signaling is involved in increasing sensitivity of olfactory physiology in Drosophila. The effect of pertussis toxin was independent of odorant identity and intensity, indicating a generalized involvement of Go in olfactory reception. Conclusion These results demonstrate that Go is required for maximal physiological responses to multiple odorants in Drosophila, and suggest that OR channel function and G-protein signaling are required for optimal physiological responses to odors.

  3. The olfactory system as a puzzle: playing with its pieces.

    Science.gov (United States)

    Díaz, D; Gómez, C; Muñoz-Castañeda, R; Baltanás, F; Alonso, J R; Weruaga, E

    2013-09-01

    The mammalian olfactory bulb (OB) has all the features of a whole mammalian brain but in a more reduced space: neuronal lamination, sensory inputs, afferences, or efferences to other centers of the central nervous system, or a contribution of new neural elements. Therefore, it is widely considered as "a brain inside the brain." Although this rostral region has the same origin and general layering as the other cerebral cortices, some distinctive features make it very profitable in experimentation in neurobiology: the sensory inputs are driven directly on its surface, the main output can be accessed anatomically, and new elements appear in it throughout adult life. These three morphological characteristics have been manipulated to analyze further the response of the whole OB. The present review offers a general outlook into the consequences of such experimentation in the anatomy, connectivity and neurochemistry of the OB after (a) sensory deprivation, mainly by naris occlusion; (b) olfactory deinnervation by means of olfactory epithelium damage, olfactory nerve interruption, or even olfactory tract disruption; (c) the removal of the principal neurons of the OB; and (d) management of the arrival of newborn interneurons from the rostral migratory stream. These experiments were performed using surgical or chemical methods, but also by means of the analysis of genetic models, some of whose olfactory components are missing, colorless or mismatching within the wild-type scenario of odor processing.

  4. Genetic control of wiring specificity in the fly olfactory system.

    Science.gov (United States)

    Hong, Weizhe; Luo, Liqun

    2014-01-01

    Precise connections established between pre- and postsynaptic partners during development are essential for the proper function of the nervous system. The olfactory system detects a wide variety of odorants and processes the information in a precisely connected neural circuit. A common feature of the olfactory systems from insects to mammals is that the olfactory receptor neurons (ORNs) expressing the same odorant receptor make one-to-one connections with a single class of second-order olfactory projection neurons (PNs). This represents one of the most striking examples of targeting specificity in developmental neurobiology. Recent studies have uncovered central roles of transmembrane and secreted proteins in organizing this one-to-one connection specificity in the olfactory system. Here, we review recent advances in the understanding of how this wiring specificity is genetically controlled and focus on the mechanisms by which transmembrane and secreted proteins regulate different stages of the Drosophila olfactory circuit assembly in a coordinated manner. We also discuss how combinatorial coding, redundancy, and error-correcting ability could contribute to constructing a complex neural circuit in general.

  5. Appetite suppression through smelling of dark chocolate correlates with changes in ghrelin in young women

    NARCIS (Netherlands)

    Massolt, Elske T.; van Haard, Paul M.; Rehfeld, Jens F.; Posthuma, Eduardus F.; van der Veer, Eveline; Schweitzer, Dave H.

    2010-01-01

    Cephalic effects on appetite are mediated by vagal tone and altered gastrointestinal hormones. The objective of this study is to explore the relationship between appetite and levels of gastrointestinal hormones after smelling chocolate and after melt-and-swallow 30 g chocolate (1.059 oz, 85% cocoa,

  6. An appropriate tool for appetite testing and evaluation in young children in Benin

    NARCIS (Netherlands)

    Dossa, R.A.; Ategbo, E.A.; Raaij, van J.M.; Graaf, de C.; Hautvast, J.G.A.J.

    2002-01-01

    Appetite measurements were performed in 109 Beninese children aged 18–30 months to develop a tool for appetite evaluation in young children in nutritional intervention programmes. Two test foods were identified as appropriate for these children: a maize porridge (aklui) and rice (riz-au-gras). Ad li

  7. Effects of multivitamin-multimineral supplementation on appetite of stunted young Beninese children

    NARCIS (Netherlands)

    Dossa, R.A.M.; Ategbo, E.A.D.; Raaij, van J.M.A.; Graaf, de C.; Hautvast, J.G.A.J.

    2002-01-01

    In the developing world, food intake of young children is often insufficient for growth. Reduced appetite due to several factors including micronutrient deficiencies might be an explanation. We hypothesized that a multivitamin-multimineral supplementation will improve appetite of stunted children in

  8. The relationship between appetite and food preferences in British and Australian children

    NARCIS (Netherlands)

    Fildes, A.; Mallan, K.M.; Cooke, L.; Jaarsveld, C.H.M. van; Llewellyn, C.H.; Fisher, A.; Daniels, L.

    2015-01-01

    BACKGROUND: Appetitive traits and food preferences are key determinants of children's eating patterns but it is unclear how these behaviours relate to one another. This study explores relationships between appetitive traits and preferences for fruits and vegetables, and energy dense, nutrient poor (

  9. Appetite suppression through smelling of dark chocolate correlates with changes in ghrelin in young women

    NARCIS (Netherlands)

    Massolt, Elske T.; van Haard, Paul M.; Rehfeld, Jens F.; Posthuma, Eduardus F.; van der Veer, Eveline; Schweitzer, Dave H.

    2010-01-01

    Cephalic effects on appetite are mediated by vagal tone and altered gastrointestinal hormones. The objective of this study is to explore the relationship between appetite and levels of gastrointestinal hormones after smelling chocolate and after melt-and-swallow 30 g chocolate (1.059 oz, 85% cocoa,

  10. How does not responding to appetitive stimuli cause devaluation: Evaluative conditioning or response inhibition?

    NARCIS (Netherlands)

    Chen, Z.; Veling, H.P.; Dijksterhuis, A.J.; Holland, R.W.

    2016-01-01

    In a series of 6 experiments (5 preregistered), we examined how not responding to appetitive stimuli causes devaluation. To examine this question, a go/no-go task was employed in which appetitive stimuli were consistently associated with cues to respond (go stimuli), or with cues to not respond

  11. Neural Correlates of Appetitive-Aversive Interactions in Pavlovian Fear Conditioning

    Science.gov (United States)

    Nasser, Helen M.; McNally, Gavan P.

    2013-01-01

    We used Pavlovian counterconditioning in rats to identify the neural mechanisms for appetitive-aversive motivational interactions. In Stage I, rats were trained on conditioned stimulus (CS)-food (unconditioned stimulus [US]) pairings. In Stage II, this appetitive CS was transformed into a fear CS via pairings with footshock. The development of…

  12. Khat use and appetite: An overview and comparison of amphetamine, khat and cathinone

    Science.gov (United States)

    Lemieux, Andrine M.; Li, Bingshuo; al’Absi, Mustafa

    2014-01-01

    Ethnopharmacological relevance To understand the role of khat (Catha edulis) use on the aberrations in appetite and weight which are common comorbidities for khat and other amphetamine users. Materials and methods We provide a comprehensive overview and conceptual summary of the historical cultural use of khat as a natural stimulant and describe the similarities and differences between cathinone (the main psychoactive constituent of khat) and amphetamine highlighting the limited literature on the neurophysiology of appetite and subsequent weight effects of khat. Results Animal and some human studies indicate that khat produces appetite suppression, although little is known about mechanisms of this effect. Both direct and indirect effects of khat stem from multiple factors including behavioral, chemical and neurophysiological effects on appetite and metabolism. Classic and newly identified appetite hormones have not been explored sufficiently in the study of appetite and khat use. Unique methodological challenges and opportunities are encountered when examining effects of khat and cathinone including khat-specific medical comorbidities, unique route of administration, differential patterns of behavioral effects relative to amphetamines and the nascent state of our understanding of the neurobiology of this drug. Conclusion A considerable amount of work remains in the study of the appetite effects of khat chewing and outline a program of research that could inform our understanding of this natural amphetamine’s appetite effects and help prepare health care workers for the unique health effects of this drug. PMID:25435289

  13. Development of a lack of appetite item bank for computer-adaptive testing (CAT)

    NARCIS (Netherlands)

    Thamsborg, L.H.; Petersen, M.A.; Aaronson, N.K.; Chie, W.C.; Costantini, A.; Holzner, B.; Verdonck-de Leeuw, I.M.; Young, T.; Groenvold, M.

    2015-01-01

    Purpose: A significant proportion of oncological patients experiences lack of appetite. Precise measurement is relevant to improve the management of lack of appetite. The so-called computer-adaptive test (CAT) allows for adaptation of the questionnaire to the individual patient, thereby optimizing

  14. How does not responding to appetitive stimuli cause devaluation: Evaluative conditioning or response inhibition?

    NARCIS (Netherlands)

    Chen, Z.; Veling, H.P.; Dijksterhuis, A.J.; Holland, R.W.

    2016-01-01

    In a series of 6 experiments (5 preregistered), we examined how not responding to appetitive stimuli causes devaluation. To examine this question, a go/no-go task was employed in which appetitive stimuli were consistently associated with cues to respond (go stimuli), or with cues to not respond (eit

  15. Quality Coding by Neural Populations in the Early Olfactory Pathway: Analysis Using Information Theory and Lessons for Artificial Olfactory Systems

    Science.gov (United States)

    Fonollosa, Jordi; Gutierrez-Galvez, Agustin; Marco, Santiago

    2012-01-01

    In this article, we analyze the ability of the early olfactory system to detect and discriminate different odors by means of information theory measurements applied to olfactory bulb activity images. We have studied the role that the diversity and number of receptor neuron types play in encoding chemical information. Our results show that the olfactory receptors of the biological system are low correlated and present good coverage of the input space. The coding capacity of ensembles of olfactory receptors with the same receptive range is maximized when the receptors cover half of the odor input space - a configuration that corresponds to receptors that are not particularly selective. However, the ensemble’s performance slightly increases when mixing uncorrelated receptors of different receptive ranges. Our results confirm that the low correlation between sensors could be more significant than the sensor selectivity for general purpose chemo-sensory systems, whether these are biological or biomimetic. PMID:22719851

  16. Characterizing the Input-Output Function of the Olfactory-Limbic Pathway in the Guinea Pig

    Directory of Open Access Journals (Sweden)

    Gian Luca Breschi

    2015-01-01

    Full Text Available Nowadays the neuroscientific community is taking more and more advantage of the continuous interaction between engineers and computational neuroscientists in order to develop neuroprostheses aimed at replacing damaged brain areas with artificial devices. To this end, a technological effort is required to develop neural network models which can be fed with the recorded electrophysiological patterns to yield the correct brain stimulation to recover the desired functions. In this paper we present a machine learning approach to derive the input-output function of the olfactory-limbic pathway in the in vitro whole brain of guinea pig, less complex and more controllable than an in vivo system. We first experimentally characterized the neuronal pathway by delivering different sets of electrical stimuli from the lateral olfactory tract (LOT and by recording the corresponding responses in the lateral entorhinal cortex (l-ERC. As a second step, we used information theory to evaluate how much information output features carry about the input. Finally we used the acquired data to learn the LOT-l-ERC “I/O function,” by means of the kernel regularized least squares method, able to predict l-ERC responses on the basis of LOT stimulation features. Our modeling approach can be further exploited for brain prostheses applications.

  17. Characterizing the Input-Output Function of the Olfactory-Limbic Pathway in the Guinea Pig.

    Science.gov (United States)

    Breschi, Gian Luca; Ciliberto, Carlo; Nieus, Thierry; Rosasco, Lorenzo; Taverna, Stefano; Chiappalone, Michela; Pasquale, Valentina

    2015-01-01

    Nowadays the neuroscientific community is taking more and more advantage of the continuous interaction between engineers and computational neuroscientists in order to develop neuroprostheses aimed at replacing damaged brain areas with artificial devices. To this end, a technological effort is required to develop neural network models which can be fed with the recorded electrophysiological patterns to yield the correct brain stimulation to recover the desired functions. In this paper we present a machine learning approach to derive the input-output function of the olfactory-limbic pathway in the in vitro whole brain of guinea pig, less complex and more controllable than an in vivo system. We first experimentally characterized the neuronal pathway by delivering different sets of electrical stimuli from the lateral olfactory tract (LOT) and by recording the corresponding responses in the lateral entorhinal cortex (l-ERC). As a second step, we used information theory to evaluate how much information output features carry about the input. Finally we used the acquired data to learn the LOT-l-ERC "I/O function," by means of the kernel regularized least squares method, able to predict l-ERC responses on the basis of LOT stimulation features. Our modeling approach can be further exploited for brain prostheses applications.

  18. Behavioural Susceptibility Theory: Professor Jane Wardle and the Role of Appetite in Genetic Risk of Obesity.

    Science.gov (United States)

    Llewellyn, Clare H; Fildes, Alison

    2017-03-01

    There is considerable variability in human body weight, despite the ubiquity of the 'obesogenic' environment. Human body weight has a strong genetic basis and it has been hypothesised that genetic susceptibility to the environment explains variation in human body weight, with differences in appetite being implicated as the mediating mechanism; so-called 'behavioural susceptibility theory' (BST), first described by Professor Jane Wardle. This review summarises the evidence for the role of appetite as a mediator of genetic risk of obesity. Variation in appetitive traits is observable from infancy, drives early weight gain and is highly heritable in infancy and childhood. Obesity-related common genetic variants identified through genome-wide association studies show associations with appetitive traits, and appetite mediates part of the observed association between genetic risk and adiposity. Obesity results from an interaction between genetic susceptibility to overeating and exposure to an 'obesogenic' food environment.

  19. Sir David Cuthbertson Medal Lecture. Bariatric surgery as a model to study appetite control.

    Science.gov (United States)

    Bueter, Marco; le Roux, Carel W

    2009-08-01

    The obesity epidemic and its associated morbidity and mortality have led to major research efforts to identify mechanisms that regulate appetite. Gut hormones have recently been found to be an important element in appetite regulation as a result of the signals from the periphery to the brain. Candidate hormones include ghrelin, peptide YY, glucagon-like peptide-1 and gastric inhibitory polypeptide, all of which are currently being investigated as potential obesity treatments. Bariatric surgery is currently the most effective therapy for substantial and sustained weight loss. Understanding how levels of gut hormones are modulated by such procedures has greatly contributed to the comprehension of the underlying mechanisms of appetite and obesity. The present paper is a review of how appetite and levels of gastrointestinal hormones are altered after bariatric surgery. Basic principles of common bariatric procedures and potential mechanisms for appetite regulation by gut hormones are also addressed.

  20. 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

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Olfactory cleft computed tomography analysis and olfaction in chronic rhinosinusitis

    Science.gov (United States)

    Kohli, Preeti; Schlosser, Rodney J.; Storck, Kristina

    2016-01-01

    Background: Volumetric analysis of the olfactory cleft by using computed tomography has been associated with olfaction in patients with chronic rhinosinusitis (CRS). However, existing studies have not comprehensively measured olfaction, and it thus remains unknown whether correlations differ across specific dimensions of odor perception. Objective: To use comprehensive measures of patient-reported and objective olfaction to evaluate the relationship between volumetric olfactory cleft opacification and olfaction. Methods: Olfaction in patients with CRS was evaluated by using “Sniffin' Sticks” tests and a modified version of the Questionnaire of Olfactory Disorders. Olfactory cleft opacification was quantified by using two- and three-dimensional, computerized volumetric analysis. Correlations between olfactory metrics and olfactory cleft opacification were then calculated. Results: The overall CRS cohort included 26 patients without nasal polyposis (CRSsNP) (68.4%) and 12 patients with nasal polyposis (CRSwNP) (31.6%). Across the entire cohort, total olfactory cleft opacification was 82.8%, with greater opacification in the CRSwNP subgroup compared with CRSsNP (92.3 versus 78.4%, p < 0.001). The percent total volume opacification correlated with the total Sniffin' Sticks score (r = −0.568, p < 0.001) as well as individual threshold, discrimination, and identification scores (p < 0.001 for all). Within the CRSwNP subgroup, threshold (r = −0.616, p = 0.033) and identification (r = −0.647, p = 0.023) remained highly correlated with total volume opacification. In patients with CRSsNP, the threshold correlated with total volume scores (r = −0.457, p = 0.019), with weaker and nonsignificant correlations for discrimination and identification. Correlations between total volume opacification and the Questionnaire of Olfactory Disorders were qualitatively similar to objective olfactory findings in both CRSwNP (r = −0.566, p = 0.070) and CRSsNP (r = −0.310, p

  3. System identification of Drosophila olfactory sensory neurons.

    Science.gov (United States)

    Kim, Anmo J; Lazar, Aurel A; Slutskiy, Yevgeniy B

    2011-02-01

    The lack of a deeper understanding of how olfactory sensory neurons (OSNs) encode odors has hindered the progress in understanding the olfactory signal processing in higher brain centers. Here we employ methods of system identification to investigate the encoding of time-varying odor stimuli and their representation for further processing in the spike domain by Drosophila OSNs. In order to apply system identification techniques, we built a novel low-turbulence odor delivery system that allowed us to deliver airborne stimuli in a precise and reproducible fashion. The system provides a 1% tolerance in stimulus reproducibility and an exact control of odor concentration and concentration gradient on a millisecond time scale. Using this novel setup, we recorded and analyzed the in-vivo response of OSNs to a wide range of time-varying odor waveforms. We report for the first time that across trials the response of OR59b OSNs is very precise and reproducible. Further, we empirically show that the response of an OSN depends not only on the concentration, but also on the rate of change of the odor concentration. Moreover, we demonstrate that a two-dimensional (2D) Encoding Manifold in a concentration-concentration gradient space provides a quantitative description of the neuron's response. We then use the white noise system identification methodology to construct one-dimensional (1D) and two-dimensional (2D) Linear-Nonlinear-Poisson (LNP) cascade models of the sensory neuron for a fixed mean odor concentration and fixed contrast. We show that in terms of predicting the intensity rate of the spike train, the 2D LNP model performs on par with the 1D LNP model, with a root mean-square error (RMSE) increase of about 5 to 10%. Surprisingly, we find that for a fixed contrast of the white noise odor waveforms, the nonlinear block of each of the two models changes with the mean input concentration. The shape of the nonlinearities of both the 1D and the 2D LNP model appears to be

  4. The SEEKING mind: primal neuro-affective substrates for appetitive incentive states and their pathological dynamics in addictions and depression.

    Science.gov (United States)

    Alcaro, Antonio; Panksepp, Jaak

    2011-10-01

    Appetitive motivation and incentive states are essential functions sustained by a common emotional brain process, the SEEKING disposition, which drives explorative and approach behaviors, sustains goal-directed activity, promotes anticipatory cognitions, and evokes feelings of positive excitement which control reward-learning. All such functions are orchestrated by the same "archetypical" neural processes, activated in ancient subcortical areas and transported to the forebrain by the mesolimbic dopamine (ML-DA) system. In mammals, the neurophysiology of the SEEKING urge is expressed by DA-promoted high-frequency oscillations, in the form of transient and synchronized gamma waves (>30Hz) emerging in limbic forebrain and diffusing throughout basal ganglia-thalamocortical (BG-T-C) circuits. These patterns may be considered basic "SEEKING neurodynamic impulses" which represent the primary-process exploratory disposition getting integrated with information relative to the external and the internal environment. Abnormal manifestation of SEEKING and its neural substrates are evident in clinical depression and addiction. Specifically, depression is characterized by reduced recruitment of SEEKING, while addictions reflect re-organizations of the SEEKING disposition around ultra-specific appetitive memories and compulsive activities.

  5. Centrifugal telencephalic afferent connections to the main and accessory olfactory bulbs

    Directory of Open Access Journals (Sweden)

    Alicia eMohedanoMoriano

    2012-05-01

    Full Text Available Parallel to the olfactory system, most mammals possess an accessory olfactory or vomeronasal system. The olfactory and vomeronasal epithelia project to the main and accessory olfactory bulbs, which in turn project to adjacent areas of the telencephalon, respectively. New data indicate that projections arising from the main and accessory olfactory bulbs partially converge in the rostral telencephalon and are non-overlapping at caudal telencephalic levels. Therefore, the basal telencephalon should be reclassified in olfactory, vomeronasal and mixed areas. On the other hand, it has been demonstrated that virtually all olfactory- and vomeronasal-recipient structures send reciprocal projections to the main and accessory olfactory bulbs, respectively. Further, non-chemosensory recipient structures also projects centrifugally to the olfactory bulbs. These feed-back projections appear to be essential modulating processing of chemosensory information. The present work aims at characterizing centrifugal projections to the main and accessory olfactory bulbs arising from olfactory, vomeronasal, mixed and non-chemosensory recipient telencephalic areas. This issue has been addressed by using tracer injections in the rat and mouse brain. Tracer injections were delivered into the main and accessory olfactory bulbs as well as in olfactory, vomeronasal, mixed and non-chemosensory recipient telencephalic structures. The results confirm that olfactory- and vomeronasal-recipient structures project to the main and accessory olfactory bulbs, respectively. Interestingly, olfactory (e.g., piriform cortex, vomeronasal (e.g., posteromedial cortical amygdala, mixed (e.g., the medial amygdala and non-chemosensory-recipient (e.g., the nucleus of the diagonal band structures project to the main and to the accessory olfactory bulbs thus providing the possibility of simultaneous modulation and interaction of both systems at different stages of chemosensory processing.

  6. Centrifugal telencephalic afferent connections to the main and accessory olfactory bulbs

    Science.gov (United States)

    Mohedano-Moriano, Alicia; de la Rosa-Prieto, Carlos; Saiz-Sanchez, Daniel; Ubeda-Bañon, Isabel; Pro-Sistiaga, Palma; de Moya-Pinilla, Miguel; Martinez-Marcos, Alino

    2012-01-01

    Parallel to the olfactory system, most mammals possess an accessory olfactory or vomeronasal system. The olfactory and vomeronasal epithelia project to the main and accessory olfactory bulbs, which in turn project to adjacent areas of the telencephalon, respectively. New data indicate that projections arising from the main and accessory olfactory bulbs partially converge in the rostral telencephalon and are non-overlapping at caudal telencephalic levels. Therefore, the basal telencephalon should be reclassified in olfactory, vomeronasal, and mixed areas. On the other hand, it has been demonstrated that virtually all olfactory- and vomeronasal-recipient structures send reciprocal projections to the main and accessory olfactory bulbs, respectively. Further, non-chemosensory recipient structures also projects centrifugally to the olfactory bulbs. These feed-back projections appear to be essential modulating processing of chemosensory information. The present work aims at characterizing centrifugal projections to the main and accessory olfactory bulbs arising from olfactory, vomeronasal, mixed, and non-chemosensory recipient telencephalic areas. This issue has been addressed by using tracer injections in the rat and mouse brain. Tracer injections were delivered into the main and accessory olfactory bulbs as well as in olfactory, vomeronasal, mixed, and non-chemosensory recipient telencephalic structures. The results confirm that olfactory- and vomeronasal-recipient structures project to the main and accessory olfactory bulbs, respectively. Interestingly, olfactory (e.g., piriform cortex), vomeronasal (e.g., posteromedial cortical amygdala), mixed (e.g., the anterior medial amygdaloid nucleus), and non-chemosensory-recipient (e.g., the nucleus of the diagonal band) structures project to the main and to the accessory olfactory bulbs thus providing the possibility of simultaneous modulation and interaction of both systems at different stages of chemosensory processing

  7. 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.

  8. A model of cholinergic modulation in olfactory bulb and piriform cortex.

    Science.gov (United States)

    de Almeida, Licurgo; Idiart, Marco; Linster, Christiane

    2013-03-01

    In this work we investigate in a computational model how cholinergic inputs to the olfactory bulb (OB) and piriform cortex (PC) modulate odor representations. We use experimental data derived from different physiological studies of ACh modulation of the bulbar and cortical circuitry and the interaction between these two areas. The results presented here indicate that cholinergic modulation in the OB significantly increases contrast and synchronization in mitral cell output. Each of these effects is derived from distinct neuronal interactions, with different groups of interneurons playing different roles. Both bulbar modulation effects contribute to more stable learned representations in PC, with pyramidal networks trained with cholinergic-modulated inputs from the bulb exhibiting more robust learning than those trained with unmodulated bulbar inputs. This increased robustness is evidenced as better recovery of memories from corrupted patterns and lower-concentration inputs as well as increased memory capacity.

  9. Olfactory functions after transsphenoidal pituitary surgery: endoscopic versus microscopic approach.

    Science.gov (United States)

    Kahilogullari, Gokmen; Beton, Suha; Al-Beyati, Eyyub S M; Kantarcioglu, Ozlem; Bozkurt, Melih; Kantarcioglu, Emrah; Comert, Ayhan; Unlu, M Agahan; Meco, Cem

    2013-09-01

    Olfactory disturbances could be observed following transsphenoidal pituitary surgeries. To our knowledge, no previous comparative studies on olfactory functions after transsphenoidal endoscopic and microscopic approaches have been performed. Prospective study comparing olfactory functions between endoscopic and microscopic transsphenoidal pituitary surgery. Twenty-five patients operated on with the endoscopic approach and 25 patients operated on with the microscopic transsphenoidal approach have been evaluated. The Smell Diskettes Olfaction Test was used during the preoperative period, 1 month after the operation, and 6 months after the operation. In addition, the relationship between intraoperative cerebrospinal fluid leakage from the pituitary and postoperative synechiae formation with olfaction system was evaluated. The results were analyzed using the Friedman test, Mann-Whitney test, and Chi-Square test. In the endoscopic group, there were two hyposmic patients and no anosmic patients. In the microscopic group, there were 13 hyposmic patients and five anosmic patients. The data was statistically different between both groups (P microscopic group. There was no statistically significant difference between cerebrospinal fluid leakage and olfactory disturbances in both groups (P >0.05). Synechia was observed in nine patients in the microscopic group and in only one patient in the endoscopic group. There was a statistically significant difference between the presence of synechia and olfactory disturbances (P microscopic transsphenoidal approaches on the olfactory system during pituitary surgery. The obtained results indicate that an endoscopic approach seems to be more advantageous than a microscopic approach for protecting olfactory system and function. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  10. 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.

  11. 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

    2014-08-04

    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.

  12. CART in the regulation of appetite and energy homeostasis.

    Science.gov (United States)

    Lau, Jackie; Herzog, Herbert

    2014-01-01

    The cocaine- and amphetamine-regulated transcript (CART) has been the subject of significant interest for over a decade. Work to decipher the detailed mechanism of CART function has been hampered by the lack of specific pharmacological tools like antagonists and the absence of a specific CART receptor(s). However, extensive research has been devoted to elucidate the role of the CART peptide and it is now evident that CART is a key neurotransmitter and hormone involved in the regulation of diverse biological processes, including food intake, maintenance of body weight, reward and addiction, stress response, psychostimulant effects and endocrine functions (Rogge et al., 2008; Subhedar et al., 2014). In this review, we focus on knowledge gained on CART's role in controlling appetite and energy homeostasis, and also address certain species differences between rodents and humans.

  13. CART in the regulation of appetite and energy homeostasis

    Science.gov (United States)

    Lau, Jackie; Herzog, Herbert

    2014-01-01

    The cocaine- and amphetamine-regulated transcript (CART) has been the subject of significant interest for over a decade. Work to decipher the detailed mechanism of CART function has been hampered by the lack of specific pharmacological tools like antagonists and the absence of a specific CART receptor(s). However, extensive research has been devoted to elucidate the role of the CART peptide and it is now evident that CART is a key neurotransmitter and hormone involved in the regulation of diverse biological processes, including food intake, maintenance of body weight, reward and addiction, stress response, psychostimulant effects and endocrine functions (Rogge et al., 2008; Subhedar et al., 2014). In this review, we focus on knowledge gained on CART's role in controlling appetite and energy homeostasis, and also address certain species differences between rodents and humans. PMID:25352770

  14. Hippocampal unit activity during classical aversive and appetitive conditioning.

    Science.gov (United States)

    Segal, M; Disterhoft, J F; Olds, J

    1972-02-18

    Rats were trained with a tone being followed by either food or electric shock, on alternate days. Unit activity during application of the conditioned stimulus was recorded from the dorsal hippocampus. The results indicate differentiation of the hippocampal system. Dentate units respond by augmentation to a conditioned stimulus which leads to food and by inhibition to the same stimulus when it precedes electric shock. The hippocampus proper responds by augmentation in both situations. The intensity of the hippocampal response to the conditioned stimulus on the first day of training is higher if the unconditioned stimulus is food than if it is electric shock. These data cast light on the functions of the dorsal dentate-hippocampal connections and the hippocampus proper during aversive and appetitive conditioning.

  15. CART in the Regulation of Appetite and Energy Homeostasis

    Directory of Open Access Journals (Sweden)

    Jackie eLau

    2014-10-01

    Full Text Available The cocaine- and amphetamine-regulated transcript (CART has been the subject of significant interest for over a decade. Work to decipher the detailed mechanism of CART function has been hampered by the lack of specific pharmacological tools like antagonists and the absence of a specific CART receptor(s. However, extensive research has been devoted to elucidate the role of the CART peptide and it is now evident that CART is a key neurotransmitter and hormone involved in the regulation of diverse biological processes, including food intake, maintenance of body weight, reward and addiction, stress response, psychostimulant effects and endocrine functions1,2. In this review, we focus on knowledge gained on CART’s role in controlling appetite and energy homeostasis, and also address certain species differences between rodents and humans.

  16. Feeding frequency and appetite in lean and obese prepubertal children.

    Science.gov (United States)

    Mehra, Rinku; Tsalikian, Eva; Chenard, Catherine A; Zimmerman, M Bridget; Sivitz, William I

    2011-03-01

    To determine the effect of feeding frequency on appetite in normal weight (NW) and obese (OB) prepubertal children, we carried out a prospective, randomized interventional study of 18 NW and 17 OB children ages 6-10. Children received three or five feedings in random order on separate days. Total calories, carbohydrate, protein, and fat composition on each day were equal. Two hours following the last feeding, children were offered ice cream ad lib. The major outcome variable was kilocalories ice cream consumed. A visual analog scale to assess fullness was also administered before consumption of ice cream. We observed that OB children consumed 73.0 ± 37.4 kcal more after five feedings than after three feedings whereas the NW children consumed 47.1 ± 27.8 kcal less. There was significant interaction between meal pattern and weight group indicating that this change in ice cream consumption differed significantly between groups (P = 0.014 by two-factor analysis). Ice cream intake/kg was less in OB compared to NW subjects (P = 0.012). Fullness ratings before ice cream did not differ by meal pattern or weight group. However, pre-ice cream fullness predicted ice cream intake in NW but not OB children. In summary, OB and NW children differed in appetite response to meal frequency. Our data suggest that: (i) satiety in OB children is related more to proximity of calories (larger supper) than to antecedent distribution of calories and; (ii) NW children may be more prone to restrict intake based on subjective fullness.

  17. Olfactory assessment using the NIH Toolbox

    Science.gov (United States)

    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 in adult tests and have limited ability to read and identify labels to select among choices. Based on the format of the San Diego Odor Identification Test and the delivery system of the University of Pennsylvania Smell Identification Test, we developed 2 versions of an odor identification test using standardized odor stimuli in a scratch-and-sniff format in which participants match 5 (children) or 9 (adults) odors to pictures representing the odor source. Results from normative testing and validation showed that for most participants, the test could be completed in 5 minutes or less and that the poorer performance among the youngest children and the elderly was consistent with data from tests with larger numbers of items. Expanding on the pediatric version of the test with adult-specific and public health–relevant odors increased the ecological validity of the test and facilitated comparisons of intraindividual performance across developmental stages. PMID:23479541

  18. Management of intracranial invasive olfactory neuroblastoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-wei; ZHANG Ming-shan; QI Ji; ZHANG Jun-ting; LI Gui-lin; LUO Lin; WANG Zhong-cheng

    2007-01-01

    Background Olfactory neuroblastoma (ONB) is a rare tumor that often arise from the nasal cavity. The aim of this study was to investigate the clinical characteristics and treatments of intracranial invasive ONB.Methods Between July 2001 and August 2005, 5 patients with intracranial invasive ONB were treated in our department. Their clinical features, radiological and pathological characteristics, and surgical treatments were analyzed.Among the 5 patients, 1 received transnasal biopsy, and 4 were operated through the transfrontal or extended bifrontal approaches to reconstruct the skull base. After the operation, all the patients received radiotherapy, and one received chemotherapy. They were followed up for 6 to 45 months.Results The ONB was resected totally in the 4 patients. In all the patients, nasal obstruction was alleviated without cerebrospinal fluid leakage. The visual acuity was improved in 3 patients, who had a decreased visual acuity before the operation. Two patients had metastasis into the lumbosacral spinal canal 6 and 8 months after the operation, one of them received a second operation and the other died.Concluslon ONB has no specific symptoms. Intracranial ONB should be resected as far as possible, and treated by radiotherapy afterthe operation.

  19. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Anterior Interhemispheric Approach for Olfactory Groove Meningioma

    Directory of Open Access Journals (Sweden)

    Imam Hidayat

    2016-09-01

    Full Text Available Objective: To evaluate the surgical technique with bifrontal interhemispheric approach for total removal of tumor in olfactory groove meningioma (OGM. Methods: This study described a case of a 38-year-old woman with bilateral blindness, anosmia, and behaviour changes. Imaging studies show a tumor mass in midfrontal base. Surgery using a bifrontal interhemispheric approach was performed and total removal was achieved and postoperative computed tomography (CT scan was performed to confirm the result. Histopathological findings established a diagnosis of meningioma. Results: A coronal skin incision behind the hairline was utilized. The scalp was elevated, taking care to reserve the vascularized pericranium medial to the linea temporalis of each side, and preserving the 2 supraorbital nerves. Eight burr holes were used, with the two initial holes made on each side of the orbitotemporal region, and the other four holes at the midline. A bifrontal craniotomy was performed. The tumor was first detached from its attachment with bipolar cautery and debulked. During this step, the main tumor feeder arteries from the anterior and posterior ethmoidal artery were interrupted, and the tumor devascularized. Total tumor removal through surgical intervention was achieved and confirmed by head CT-scan postoperatively. Conclusions: This case report supports the suitability of the bifrontal interhemispheric approach for OGM resection with additional radiation therapy.