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Sample records for classical olfactory conditioning

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

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    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.

  2. 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

  3. Olfactory classical conditioning in neonatal mouse pups using thermal stimuli.

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    Bollen, Bieke; Matrot, Boris; Ramanantsoa, Nelina; Van den Bergh, Omer; D'Hooge, Rudi; Gallego, Jorge

    2012-04-01

    Mouse models are increasingly used to investigate genetic contributions to developmental disorders in children, especially newborns. In particular, early cognitive assessment in newborn mice is critical to evaluate pediatric drug efficacy and toxicity. Unfortunately, methods for behavioral tests in newborn mice are scarce. Therefore, developing such tests for newborn mice is a priority challenge for neurogenetics and pharmacological research. The aim of the present study was to develop a conditioning method well suited to high-throughput cognitive screening in newborn mice. To this end, we developed an odor-preference conditioning test using ambient temperature as an unconditioned stimulus (US) and artificial odors as conditioned stimuli (CS). First, we showed that mouse pups move toward the thermoneutral temperature when offered a choice between a thermoneutral and cold environment, thus showing thermotaxis. Second, we conducted a classical conditioning paradigm in pups aged six to ten days. In terms of central nervous system development, this period corresponds to extreme prematurity to early post-term period in humans. During acquisition, the pups were alternatively exposed to odor CS paired with either cold or warm temperatures. Immediately after acquisition, the pups underwent a two-odor choice test, which showed preference for the odor previously paired with the warm temperature, thus showing conditioning. The proposed paradigm is easy to conduct, and requires modest experimenter interference. The method is well suited for high-throughput screening of early associative disorders in newborn mice.

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

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    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.

  5. Prior classical olfactory conditioning improves odour-cued flight orientation of honey bees in a wind tunnel.

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    Chaffiol, Antoine; Laloi, David; Pham-Delègue, Minh-Hà

    2005-10-01

    Odours are key cues used by the honey bee in various situations. They play an important role in sexual attraction, social behaviour and location of profitable food sources. Here, we were interested in the role of odours in orientation at short distance, for instance the approach flight to a floral patch or in close proximity to the hive entrance. Using a newly designed wind tunnel, we investigated the orientation behaviour of the bee towards two different odours: a social odour and a floral component, linalool. We then tested the effect of prior olfactory conditioning (conditioning of the proboscis extension reflex) on subsequent flight orientation. We showed that both stimuli induced orientated behaviour (orientated flights, circling around the odour source) in up to 70% of the worker bees, social odour being slightly more attractive than the linalool. We found thereafter that orientation performance towards the floral compound can be significantly enhanced by prior classical olfactory learning. This type of information transfer, from a Pavlovian associative context to an orientation task, might allow future foragers to acquire, within the hive, relevant information about the odours and food they will encounter during their later foraging bouts.

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

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    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…

  7. Teaching and Demonstrating Classical Conditioning.

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    Sparrow, John; Fernald, Peter

    1989-01-01

    Discusses classroom demonstrations of classical conditioning and notes tendencies to misrepresent Pavlov's procedures. Describes the design and construction of the conditioner that is used for demonstrating classical conditioning. Relates how students experience conditioning, generalization, extinction, discrimination, and spontaneous recovery.…

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

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    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.

  9. 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.

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

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    Matthew Valley

    2009-11-01

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

  11. A Temporal-Specific and Transient cAMP Increase Characterizes Odorant Classical Conditioning

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    Cui, Wen; Smith, Andrew; Darby-King, Andrea; Harley, Carolyn W.; McLean, John H.

    2007-01-01

    Increases in cyclic adenosine monophosphate (cAMP) are proposed to initiate learning in a wide variety of species. Here, we measure changes in cAMP in the olfactory bulb prior to, during, and following a classically conditioned odor preference trial in rat pups. Measurements were taken up to the point of maximal CREB phosphorylation in olfactory…

  12. The usefulness of olfactory fear conditioning for the study of early emotional and cognitive impairment in reserpine model.

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    Souza, Rimenez R; França, Sanmara L; Bessa, Marília M; Takahashi, Reinaldo N

    2013-11-01

    Due to the ability for depleting neuronal storages of monoamines, the reserpine model is a suitable approach for the investigation of the neurobiology of neurodegenerative diseases. However, the behavioral effects of low doses of reserpine are not always detected by classic animal tests of cognition, emotion, and sensory ability. In this study, the effects of reserpine (0.5-1.0mg/kg) were evaluated in olfactory fear conditioning, inhibitory avoidance, open-field, elevated plus-maze, and olfactory discrimination. Possible protective effects were also investigated. We found that single administration of reserpine impaired the acquisition of olfactory fear conditioning (in both doses) as well as olfactory discrimination (in the higher dose), while no effects were seen in all other tests. Additionally, we demonstrated that prior exposure to environmental enrichment prevented effects of reserpine in animals tested in olfactory fear conditioning. Altogether, these findings suggest that a combined cognitive, emotional and sensory-dependent task would be more sensitive to the effects of the reserpine model. In addition, the present data support the environmental enrichment as an useful approach for the study of resilience mechanisms in neurodegenerative processes.

  13. Classical Conditioning: Eliciting the Right Response.

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    Tauber, Robert T.

    1990-01-01

    Classical conditioning is responsible for students' positive and negative feelings, whether directed toward subject matter, peers, teachers, or education in general. This article explains how educators can use classical conditioning principles (such as reinforcement, extinction, and paired stimuli) to create an anxiety-free learning environment.…

  14. The Role of Contingency in Classical Conditioning.

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    Papini, Mauricio R.; Bitterman, M. E.

    1990-01-01

    Early experiments suggesting that classical conditioning depends on the contingency between conditioned stimulus (CS) and the unconditioned stimulus (US) are reconsidered along with later evidence that shows conditioning of the CS and its context in random training. CS-US contingency is neither necessary nor sufficient for conditioning. (SLD)

  15. Rapid learning dynamics in individual honeybees during classical conditioning

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    Evren ePamir

    2014-09-01

    Full Text Available Associative learning in insects has been studied extensively by a multitude of classical conditioning protocols. However, so far little emphasis has been put on the dynamics of learning in individuals. The honeybee is a well-established animal model for learning and memory. We here studied associative learning as expressed in individual behavior based on a large collection of data on olfactory classical conditioning (25 datasets, 3,298 animals. We show that the group-averaged learning curve and memory retention score confound three attributes of individual learning: the ability or inability to learn a given task, the generally fast acquisition of a conditioned response in learners, and the high stability of the conditioned response during consecutive training and memory retention trials. We reassessed the prevailing view that more training results in better memory performance and found that 24h memory retention can be indistinguishable after single-trial and multiple-trial conditioning in individuals. We explain how inter-individual differences in learning can be accommodated within the Rescorla-Wagner theory of associative learning. In both data-analysis and modeling we demonstrate how the conflict between population-level and single-animal perspectives on learning and memory can be disentangled.

  16. Classical conditioning and pain: conditioned analgesia and hyperalgesia.

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    Miguez, Gonzalo; Laborda, Mario A; Miller, Ralph R

    2014-01-01

    This article reviews situations in which stimuli produce an increase or a decrease in nociceptive responses through basic associative processes and provides an associative account of such changes. Specifically, the literature suggests that cues associated with stress can produce conditioned analgesia or conditioned hyperalgesia, depending on the properties of the conditioned stimulus (e.g., contextual cues and audiovisual cues vs. gustatory and olfactory cues, respectively) and the proprieties of the unconditioned stimulus (e.g., appetitive, aversive, or analgesic, respectively). When such cues are associated with reducers of exogenous pain (e.g., opiates), they typically increase sensitivity to pain. Overall, the evidence concerning conditioned stress-induced analgesia, conditioned hyperalagesia, conditioned tolerance to morphine, and conditioned reduction of morphine analgesia suggests that selective associations between stimuli underlie changes in pain sensitivity.

  17. Effect of circadian phase on memory acquisition and recall: operant conditioning vs. classical conditioning.

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    Madeleine V Garren

    Full Text Available There have been several studies on the role of circadian clocks in the regulation of associative learning and memory processes in both vertebrate and invertebrate species. The results have been quite variable and at present it is unclear to what extent the variability observed reflects species differences or differences in methodology. Previous results have shown that following differential classical conditioning in the cockroach, Rhyparobia maderae, in an olfactory discrimination task, formation of the short-term and long-term memory is under strict circadian control. In contrast, there appeared to be no circadian regulation of the ability to recall established memories. In the present study, we show that following operant conditioning of the same species in a very similar olfactory discrimination task, there is no impact of the circadian system on either short-term or long-term memory formation. On the other hand, ability to recall established memories is strongly tied to the circadian phase of training. On the basis of these data and those previously reported for phylogenetically diverse species, it is suggested that there may be fundamental differences in the way the circadian system regulates learning and memory in classical and operant conditioning.

  18. Olfactory Detection Thresholds and Adaptation in Adults with Autism Spectrum Condition

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    Tavassoli, T.; Baron-Cohen, S.

    2012-01-01

    Sensory issues have been widely reported in Autism Spectrum Conditions (ASC). Since olfaction is one of the least investigated senses in ASC, the current studies explore olfactory detection thresholds and adaptation to olfactory stimuli in adults with ASC. 80 participants took part, 38 (18 females, 20 males) with ASC and 42 control participants…

  19. Attitudes of Children Established by Classical Conditioning.

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    Barnabei, Fred; And Others

    This study examined the attitudes of children established by classical conditioning. Subjects were 4th graders (26 males and 31 females). Each child was randomly assigned to either an experimental or a control group. A posttest-only design was used with positive and negative word associations presented to the experimental group, and neutral word…

  20. Priority in the Classical Conditioning of Children.

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    Windholz, George; Lamal, P. A.

    1986-01-01

    Contrary to widely held belief, Watons and Rayner's (1920) experiment with Little Albert is not first reported case of classical conditioning of a child. Their work was preceded by that of Bogen and of Krasnogorskii. Mateer's work either preceded or coincided with Watons and Rayner's. This article clarifies chronology of these early studies of…

  1. Stimulus Configuration, Classical Conditioning, and Hippocampal Function.

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    Schmajuk, Nestor A.; DiCarlo, James J.

    1991-01-01

    The participation of the hippocampus in classical conditioning is described in terms of a multilayer network portraying stimulus configuration. A model of hippocampal function is presented, and computer simulations are used to study neural activity in the various brain areas mapped according to the model. (SLD)

  2. Pavlovian conditioning of emotional responses to olfactory and contextual stimuli: a potential model for the development and expression of chemical intolerance.

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    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.

  3. Eyeblink classical conditioning in the preweanling lamb.

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    Johnson, Timothy B; Stanton, Mark E; Goodlett, Charles R; Cudd, Timothy A

    2008-06-01

    Classical conditioning of eyeblink responses has been one of the most important models for studying the neurobiology of learning, with many comparative, ontogenetic, and clinical applications. The current study reports the development of procedures to conduct eyeblink conditioning in preweanling lambs and demonstrates successful conditioning using these procedures. These methods will permit application of eyeblink conditioning procedures in the analysis of functional correlates of cerebellar damage in a sheep model of fetal alcohol spectrum disorders, which has significant advantages over more common laboratory rodent models. Because sheep have been widely used for studies of pathogenesis and mechanisms of injury with many different prenatal or perinatal physiological insults, eyeblink conditioning can provide a well-studied method to assess postnatal behavioral outcomes, which heretofore have not typically been pursued with ovine models of developmental insults.

  4. Demand Characteristics in Classical Verbal Conditioning and Attitude Conditioning Studies.

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    McGinley, Hugh

    This paper is a draft for the American Psychological Association Symposium on the conditioning of verbal behavior and attitudes. The author presents the results of several studies he conducted in the classical conditioning of meaning and attitude. These studies attempt to control the measurement effects created by extraneous variables operating on…

  5. Evaluating the TD model of classical conditioning.

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    Ludvig, Elliot A; Sutton, Richard S; Kehoe, E James

    2012-09-01

    The temporal-difference (TD) algorithm from reinforcement learning provides a simple method for incrementally learning predictions of upcoming events. Applied to classical conditioning, TD models suppose that animals learn a real-time prediction of the unconditioned stimulus (US) on the basis of all available conditioned stimuli (CSs). In the TD model, similar to other error-correction models, learning is driven by prediction errors--the difference between the change in US prediction and the actual US. With the TD model, however, learning occurs continuously from moment to moment and is not artificially constrained to occur in trials. Accordingly, a key feature of any TD model is the assumption about the representation of a CS on a moment-to-moment basis. Here, we evaluate the performance of the TD model with a heretofore unexplored range of classical conditioning tasks. To do so, we consider three stimulus representations that vary in their degree of temporal generalization and evaluate how the representation influences the performance of the TD model on these conditioning tasks.

  6. Classical conditioned responses to absent tones

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    Häusler Udo

    2006-08-01

    Full Text Available Abstract Background Recent evidence for a tight coupling of sensorimotor processes in trained musicians led to the question of whether this coupling extends to preattentively mediated reflexes; particularly, whether a classically conditioned response in one of the domains (auditory is generalized to another (tactile/motor on the basis of a prior association in a second-order Pavlovian paradigm. An eyeblink conditioning procedure was performed in 17 pianists, serving as a model for overlearned audiomotor integration, and 14 non-musicians. Results: During the training session, subjects were conditioned to respond to auditory stimuli (piano tones. During a subsequent testing session, when subjects performed keystrokes on a silent piano, pianists showed significantly higher blink rates than non-musicians. Conclusion These findings suggest a tight coupling of the auditory and motor domains in musicians, pointing towards training-dependent mechanisms of strong cross-modal sensorimotor associations even on sub-cognitive processing levels.

  7. Classical eyeblink conditioning in Parkinson's disease.

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    Daum, I; Schugens, M M; Breitenstein, C; Topka, H; Spieker, S

    1996-11-01

    Patients with Parkinson's disease (PD) show impairments of a range of motor learning tasks, including tracking or serial reaction time task learning. Our study investigated whether such deficits would also be seen on a simple type of motor learning, classic conditioning of the eyeblink response. Medicated and unmediated patients with PD showed intact unconditioned eyeblink responses and significant learning across acquisition; the learning rates did not differ from those of healthy control subjects. The overall frequency of conditioned responses was significantly higher in the medicated patients with PD relative to control subjects, and there was also some evidence of facilitation in the unmedicated patients with PD. Conditioning of electrodermal and electrocortical responses was comparable in all groups. The findings are discussed in terms of enhanced excitability of brainstem pathways in PD and of the involvement of different neuronal circuits in different types of motor learning.

  8. 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…

  9. Energy conditions and classical scalar fields

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    Bellucci, S

    2002-01-01

    Attention has been recently called upon the fact that the weak and null energy conditions and the second law of thermodynamics are violated in wormhole solutions of Einstein's theory with classical, nonminimally coupled, scalar fields as material source. It is shown that the discussion is only meaningful when ambiguities in the definitions of stress-energy tensor and energy density of a nonminimally coupled scalar are resolved. The three possible approaches are discussed with emphasis on the positivity of the respective energy densities and covariant conservation laws. The root of the ambiguities is traced to the energy localization problem for the gravitational field.

  10. Necessary and sufficient factors in classical conditioning.

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    Damianopoulos, E N

    1982-01-01

    The issue of necessary and sufficient factors (pairing-contiguity vs. contingency-correlation) in classical (Pavlovian) excitatory conditioning is examined: first, in terms of definitional (logical) and manipulational requirements of "necessary" and "sufficient"; second, in terms of Boolean logic test models indicating experimental and control manipulations in tests of pairing and contingency as necessary and sufficient factors; and, third, by a selective review of reference experiments showing appropriate experimental and control manipulations of pairing and contingency indicated in the Boolean logic test models. Results of examination show pairing-contiguity as the sole necessary and sufficient factor for excitatory conditioning, while contingency-correlation is conceptualized as a modulating factor controlling minimal-maximal effects of pairing-contiguity. Reservations and diagnostic experiments are indicated to assess effects of uncontrolled conditioned stimulus--unconditioned stimulus (--CS--US) probability characteristics (e.g., p (CS--US)/p (--CS--US) in truly random (TR) schedule manipulations). Similar analysis of conditioned inhibition reveals insufficient evidence to support a choice among current alternatives.

  11. Classically conditioned postural reflex in cerebellar patients.

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    Kolb, F P; Lachauer, S; Maschke, M; Timmann, D

    2004-09-01

    The aim of the current study was to compare postural responses to repetitive platform-evoked perturbations in cerebellar patients with those of healthy subjects using a classical conditioning paradigm. The perturbations consisted of tilting of the platform (unconditioned stimulus: US) at random time intervals, preceded by an auditory signal that represented the conditioning stimulus (CS). Physiological reactions were recorded biomechanically by measuring the vertical ground forces, yielding the center of vertical pressure (CVP), and electrophysiologically by EMG measurements of the main muscle groups of both legs. The recording session consisted of a control section with US-alone trials, a testing section with paired stimuli and a brief final section with US-alone trials. Healthy control subjects were divided into those establishing conditioned responses (CR) in all muscles tested (strategy I) and those with CR in the gastrocnemius muscles only (strategy II), suggesting an associative motor-related process is involved. Patients with a diffuse, non-localized disease were almost unable to establish CR. This was also true for a patient with a focal surgical lesion with no CR on the affected side but who, simultaneously, showed an essentially normal CR incidence on the intact side. During US-alone trials healthy controls exhibited a remarkable decay of the UR amplitude due to a non-associative motor-related process such as habituation. The decay was most prominent in the paired trials section. In contrast, patients showed no significant differences in the UR amplitude throughout the entire recording session. Analysis of the CVP supported the electrophysiological findings, showing CR in the controls only. The differences between the responses of control subjects and those of the cerebellar patients imply strongly that the cerebellum is involved critically in controlling associative and non-associative motor-related processes.

  12. Appetitive and aversive classical conditioning of female sexual response

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    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

  13. Imaging learning and memory: classical conditioning.

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    Schreurs, B G; Alkon, D L

    2001-12-15

    The search for the biological basis of learning and memory has, until recently, been constrained by the limits of technology to classic anatomic and electrophysiologic studies. With the advent of functional imaging, we have begun to delve into what, for many, was a "black box." We review several different types of imaging experiments, including steady state animal experiments that image the functional labeling of fixed tissues, and dynamic human studies based on functional imaging of the intact brain during learning. The data suggest that learning and memory involve a surprising conservation of mechanisms and the integrated networking of a number of structures and processes.

  14. Postural responses explored through classical conditioning.

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    Campbell, A D; Dakin, C J; Carpenter, M G

    2009-12-15

    The purpose of the study was to determine whether the central nervous system (CNS) requires the sensory feedback generated by balance perturbations in order to trigger postural responses (PRs). In Experiment 1, twenty-one participants experienced toes-up support-surface tilts in two blocks. Control blocks involved unexpected balance perturbations whereas an auditory tone cued the onset of balance perturbations in Conditioning blocks. A single Cue-Only trial followed each block (Cue-Only(Control) and Cue-Only(Conditioning) trials) in the absence of balance perturbations. Cue-Only(Conditioning) trials were used to determine whether postural perturbations were required in order to trigger PRs. Counter-balancing the order of Control and Conditioning blocks allowed Cue-Only(Control) trials to examine both the audio-spinal/acoustic startle effects of the auditory cue and the carryover effects of the initial conditioning procedure. In Experiment 2, six participants first experienced five consecutive Tone-Only trials that were followed by twenty-five conditioning trials. After conditioning, five Tone-Only trials were again presented consecutively to first elicit and then extinguish the conditioned PRs. Surface electromyography (EMG) recorded muscle activity in soleus (SOL), tibialis anterior (TA) and rectus femoris (RF). EMG onset latencies and amplitudes were calculated together with the onset latency, peak and time-to-peak of shank angular accelerations. Results indicated that an auditory cue could be conditioned to initiate PRs in multiple muscles without balance-relevant sensory triggers generated by balance perturbations. Postural synergies involving excitation of TA and RF and inhibition of SOL were observed following the Cue-Only(Conditioning) trials that resulted in shank angular accelerations in the direction required to counter the expected toes-up tilt. Postural synergies were triggered in response to the auditory cue even 15 min post-conditioning. Furthermore

  15. A Neuronal Model of Classical Conditioning.

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    1987-10-01

    cell firing. Evidence of conditioning was obtained in the form of enhanced EPSPs , with the enhancement being sustained for up to 41 minutes. The...test- EPSPs . Expericiental brain Research, 4i, 124-134. Barron, R. L. (1968). Self-organizing and kdrning control systei,,s. In 11. L. Ustreicher & D

  16. Cerebellar Secretin Modulates Eyeblink Classical Conditioning

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    Fuchs, Jason R.; Robinson, Gain M.; Dean, Aaron M.; Schoenberg, Heidi E.; Williams, Michael R.; Morielli, Anthony D.; Green, John T.

    2014-01-01

    We have previously shown that intracerebellar infusion of the neuropeptide secretin enhances the acquisition phase of eyeblink conditioning (EBC). Here, we sought to test whether endogenous secretin also regulates EBC and to test whether the effect of exogenous and endogenous secretin is specific to acquisition. In Experiment 1, rats received…

  17. Cerebellar cortical inhibition and classical eyeblink conditioning.

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    Bao, Shaowen; Chen, Lu; Kim, Jeansok J; Thompson, Richard F

    2002-02-01

    The cerebellum is considered a brain structure in which memories for learned motor responses (e.g., conditioned eyeblink responses) are stored. Within the cerebellum, however, the relative importance of the cortex and the deep nuclei in motor learning/memory is not entirely clear. In this study, we show that the cerebellar cortex exerts both basal and stimulus-activated inhibition to the deep nuclei. Sequential application of a gamma-aminobutyric acid type A receptor (GABA(A)R) agonist and a noncompetitive GABA(A)R antagonist allows selective blockade of stimulus-activated inhibition. By using the same sequential agonist and antagonist methods in behaving animals, we demonstrate that the conditioned response (CR) expression and timing are completely dissociable and involve different inhibitory inputs; although the basal inhibition modulates CR expression, the conditioned stimulus-activated inhibition is required for the proper timing of the CR. In addition, complete blockade of cerebellar deep nuclear GABA(A)Rs prevents CR acquisition. Together, these results suggest that different aspects of the memories for eyeblink CRs are encoded in the cerebellar cortex and the cerebellar deep nuclei.

  18. Making Classical Conditioning Understandable through a Demonstration Technique.

    Science.gov (United States)

    Gibb, Gerald D.

    1983-01-01

    One lemon, an assortment of other fruits and vegetables, a tennis ball, and a Galvanic Skin Response meter are needed to implement this approach to teaching about classical conditioning in introductory psychology courses. (RM)

  19. Conditions of the Classical Transmission Line Equations at High Frequency

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems in high frequency case.

  20. Classical-Conditioning Demonstrations for Elementary and Advanced Courses.

    Science.gov (United States)

    Abramson, Charles I.; And Others

    1996-01-01

    Describes two new exercises in classical conditioning that use earthworms and houseflies. The animals are available year-round and pose no risk to the students or instructor. The conditioned stimuli are odorants. These elicit a conditioned response of contraction in worms or proboscis extension in flies. (MJP)

  1. Sex differences in learning processes of classical and operant conditioning.

    Science.gov (United States)

    Dalla, Christina; Shors, Tracey J

    2009-05-25

    Males and females learn and remember differently at different times in their lives. These differences occur in most species, from invertebrates to humans. We review here sex differences as they occur in laboratory rodent species. We focus on classical and operant conditioning paradigms, including classical eyeblink conditioning, fear-conditioning, active avoidance and conditioned taste aversion. Sex differences have been reported during acquisition, retention and extinction in most of these paradigms. In general, females perform better than males in the classical eyeblink conditioning, in fear-potentiated startle and in most operant conditioning tasks, such as the active avoidance test. However, in the classical fear-conditioning paradigm, in certain lever-pressing paradigms and in the conditioned taste aversion, males outperform females or are more resistant to extinction. Most sex differences in conditioning are dependent on organizational effects of gonadal hormones during early development of the brain, in addition to modulation by activational effects during puberty and adulthood. Critically, sex differences in performance account for some of the reported effects on learning and these are discussed throughout the review. Because so many mental disorders are more prevalent in one sex than the other, it is important to consider sex differences in learning when applying animal models of learning for these disorders. Finally, we discuss how sex differences in learning continue to alter the brain throughout the lifespan. Thus, sex differences in learning are not only mediated by sex differences in the brain, but also contribute to them.

  2. Cerebellum lesion impairs eyeblink-like classical conditioning in goldfish.

    Science.gov (United States)

    Gómez, A; Durán, E; Salas, C; Rodríguez, F

    2010-03-10

    The cerebellum of mammals is an essential component of the neural circuitry underlying classical conditioning of eyeblink and other discrete responses. Although the neuroanatomical organization of the cerebellum is notably well conserved in vertebrates, little is actually known about the cerebellar learning functions in nonmammal vertebrate groups. In this work we studied whether the cerebellum of teleost fish plays a critical role in the classical conditioning of a motor response. In Experiment 1, we classically conditioned goldfish in a procedure analogous to the eyeblink conditioning paradigm commonly used in mammals. Goldfish were able to learn to express an eyeblink-like conditioned response to a predictive light (conditioned stimulus) that was paired with a mild electric shock (unconditioned stimulus). The application of unpaired and extinction control procedures demonstrated that also in teleosts the learning of this motor response depends on associative rules. In Experiment 2 we studied whether classical conditioning of this response is critically dependent on the cerebellum and independent of telencephalic structures as occurs in mammals. Cerebellum lesion prevented the acquisition of the eyeblink-like conditioned response whereas telencephalon ablation did not impair the learning of this response. No deficit was observed following lesions in the performance of the unconditioned response or in the percentage of spontaneous responses. These results suggest that cerebellum ablation in goldfish affects a critical component of the circuitry necessary for the acquisition of the conditioned response but does not interfere with the ability of the animal to perform the response itself. The striking similarity in the role of cerebellum in classical conditioning of a motor response between teleost fish and mammals suggests that this learning function of the cerebellum could be a primitive feature of the vertebrate brain that has been conserved through evolution.

  3. Role of classical conditioning in learning gastrointestinal symptoms

    Institute of Scientific and Technical Information of China (English)

    Ursula Stockhorst; Paul Enck; Sibylle Klosterhalfen

    2007-01-01

    Nausea and/or vomiting are aversive gastrointestinal (GI) symptoms. Nausea and vomiting manifest unconditionally after a nauseogenic experience. However,there is correlative, quasiexperimental and experimental evidence that nausea and vomiting can also be learned via classical (Pavlovian) conditioning and might occur in anticipation of the nauseogenic event. Classical conditioning of nausea can develop with chemotherapy in cancer patients. Initially, nausea and vomiting occur during and after the administration of cytotoxic drugs (post-treatment nausea and vomiting) as unconditioned responses (UR). In addition, 20%-30% of cancer patients receiving chemotherapy report these side effects, despite antiemetic medication, when being re-exposed to the stimuli that usually signal the chemotherapy session and its drug infusion. These symptoms are called anticipatory nausea (AN) and/or anticipatory vomiting (ANV) and are explained by classical conditioning. Moreover,there is recent evidence for the assumption that postchemotherapy nausea is at least partly influenced by learning. After summarizing the relevant assumptions of the conditioning model, revealing that a context can become a conditioned stimulus (CS), the present paper summarizes data that nausea and/or vomiting is acquired by classical conditioning and, consequently,may be alleviated by conditioning techniques. Our own research has focussed on two aspects and is emphasized here. First, a conditioned nausea model was established in healthy humans using body rotation as the nauseainducing treatment. The validity of this motion-sickness model to examine conditioning mechanisms in the acquisition and alleviation of conditioned nausea and associated endocrine and immunological responses is summarized. Results from the rotation-induced motion sickness model showed that gender is an important moderator variable to be considered in further studies.This paper concludes with a review of the application of the demonstrated

  4. Role of classical conditioning in learning gastrointestinal symptoms.

    Science.gov (United States)

    Stockhorst, Ursula; Enck, Paul; Klosterhalfen, Sibylle

    2007-07-01

    Nausea and/or vomiting are aversive gastrointestinal (GI) symptoms. Nausea and vomiting manifest unconditionally after a nauseogenic experience. However, there is correlative, quasiexperimental and experimental evidence that nausea and vomiting can also be learned via classical (Pavlovian) conditioning and might occur in anticipation of the nauseogenic event. Classical conditioning of nausea can develop with chemotherapy in cancer patients. Initially, nausea and vomiting occur during and after the administration of cytotoxic drugs (post-treatment nausea and vomiting) as unconditioned responses (UR). In addition, 20%-30% of cancer patients receiving chemotherapy report these side effects, despite antiemetic medication, when being re-exposed to the stimuli that usually signal the chemotherapy session and its drug infusion. These symptoms are called anticipatory nausea (AN) and/or anticipatory vomiting (ANV) and are explained by classical conditioning. Moreover, there is recent evidence for the assumption that post-chemotherapy nausea is at least partly influenced by learning. After summarizing the relevant assumptions of the conditioning model, revealing that a context can become a conditioned stimulus (CS), the present paper summarizes data that nausea and/or vomiting is acquired by classical conditioning and, consequently, may be alleviated by conditioning techniques. Our own research has focussed on two aspects and is emphasized here. First, a conditioned nausea model was established in healthy humans using body rotation as the nausea-inducing treatment. The validity of this motion-sickness model to examine conditioning mechanisms in the acquisition and alleviation of conditioned nausea and associated endocrine and immunological responses is summarized. Results from the rotation-induced motion sickness model showed that gender is an important moderator variable to be considered in further studies. This paper concludes with a review of the application of the

  5. Allocation of cognitive processing capacity during human autonomic classical conditioning.

    Science.gov (United States)

    Dawson, M E; Schell, A M; Beers, J R; Kelly, A

    1982-09-01

    In each of two experiments, allocation of cognitive processing capacity was measured in college-student subjects during autonomic discrimination classical conditioning. A 7.0-sec delay paradigm was used to establish classically conditioned responses to a reinforced visual conditioned stimulus (CS+). Electrodermal responses were the primary measures of autonomic classical conditioning. Allocation of processing capacity was measured by monitoring performance on a secondary reaction-time (RT) task. The auditory secondary-task RT signal was presented before, and 300, 500, 3500, 6500, and 7500 msec following CS onset. The RT signal was also presented following properly and improperly cued shock unconditioned stimuli (UCSs). Significant discrimination classical conditioning was obtained in both experiments. Comparison with control subjects who did not receive the RT signals indicated that the presence of the RT signals did not interfere with the development of classical conditioning. Four principal findings were obtained with the secondary-task RT measure. First, RTs to signals presented during CS+ were consistently slower than RTs to signals presented during CS-. This finding indicates that greater capacity allocation occurred during CS+ than CS- and is consistent with recent cognitive interpretations of classical conditioning. Second, the largest capacity allocation (i.e., slowing of RTs) occurred 300 msec following CS+ onset. This finding is consistent with the notion that subjects are actively processing the signal properties of the CS+ at 300 msec following CS+ onset. Third, presentation of the UCS when improperly cued (following CS-) significantly increased capacity allocation, whereas presentation of the same UCS when properly cued (following CS+) did not affect capacity allocation. These findings indicate that subjects were actively prepared for the UCS following CS+ but not following CS- and that a surprising UCS elicits greater capacity allocation than does an

  6. Normal eyeblink classical conditioning in patients with fixed dystonia

    NARCIS (Netherlands)

    Janssen, S.; Veugen, L.C.; Hoffland, B.S.; Kassavetis, P.; Rooijen, D.E. van; Stegeman, D.F.; Edwards, Mark J.; Hilten, J.J. van; Warrenburg, B.P.C. van de

    2014-01-01

    Fixed dystonia without evidence of basal ganglia lesions or neurodegeneration typically affects young women following minor peripheral trauma. We use eyeblink classical conditioning (EBCC) to study whether cerebellar functioning is abnormal in patients with fixed dystonia, since this is part of the

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

    Science.gov (United States)

    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.

  8. Transference in view of a classical conditioning model.

    Science.gov (United States)

    Rabinovich, Merav; Kacen, Lea

    2012-01-01

    This article presents a qualitative metasynthetic study, addressing 33 transference case studies, that investigates the interrelationship of the transference concept from psychoanalysis and cognitive-behavioral concepts in an attempt to construct a theoretical platform for clinical integration. Relationship between categories analysis was used to compare Luborsky's (1998) transference components (wish, response from other, and response of self) and cognitive-behavioral ones. Results showed reciprocal relations between transference and classical conditioning. Furthermore, explicit occurrences of distorted thinking due to overgeneralization were found in more than 90% of the cases. A conceptual model describes transference as a conditioned response activated by thematic conditioning, a particular case of classical conditioning that repeatedly pairs a given interpersonal situation with internal thematic stimuli, thus shaping the person's narrative. Theoretical and practical implications are discussed as well.

  9. Pavlov's cockroach: classical conditioning of salivation in an insect.

    Directory of Open Access Journals (Sweden)

    Hidehiro Watanabe

    Full Text Available Secretion of saliva to aid swallowing and digestion is an important physiological function found in many vertebrates and invertebrates. Pavlov reported classical conditioning of salivation in dogs a century ago. Conditioning of salivation, however, has been so far reported only in dogs and humans, and its underlying neural mechanisms remain elusive because of the complexity of the mammalian brain. We previously reported that, in cockroaches Periplaneta americana, salivary neurons that control salivation exhibited increased responses to an odor after conditioning trials in which the odor was paired with sucrose solution. However, no direct evidence of conditioning of salivation was obtained. In this study, we investigated the effects of conditioning trials on the level of salivation. Untrained cockroaches exhibited salivary responses to sucrose solution applied to the mouth but not to peppermint or vanilla odor applied to an antenna. After differential conditioning trials in which an odor was paired with sucrose solution and another odor was presented without pairing with sucrose solution, sucrose-associated odor induced an increase in the level of salivation, but the odor presented alone did not. The conditioning effect lasted for one day after conditioning trials. This study demonstrates, for the first time, classical conditioning of salivation in species other than dogs and humans, thereby providing the first evidence of sophisticated neural control of autonomic function in insects. The results provide a useful model system for studying cellular basis of conditioning of salivation in the simpler nervous system of insects.

  10. In vitro classical conditioning of abducens nerve discharge in turtles.

    Science.gov (United States)

    Keifer, J; Armstrong, K E; Houk, J C

    1995-07-01

    In vitro classical conditioning of abducens nerve activity was performed using an isolated turtle brainstem-cerebellum preparation by direct stimulation of the cranial nerves. Using a delayed training procedure, the in vitro preparation was presented with paired stimuli consisting of a 1 sec train stimulus applied to the auditory nerve (CS), which immediately preceded a single shock US applied to the trigeminal nerve. Conditioned and unconditioned responses were recorded in the ipsilateral abducens nerve. Acquisition exhibited a positive slope of conditioned responding in 60% of the preparations. Application of unpaired stimuli consisting of CS-alone, alternate CS and US, or backward conditioning failed to result in conditioning, or resulted in extinction of CRs. Latencies of CR onset were timed such that they occurred midway through the CS. Activity-dependent uptake of the dye sulforhodamine was used to examine the spatial distribution of neurons labeled during conditioning. These data showed label in the cerebellum and red nucleus during conditioning whereas these regions failed to label during unconditioned responses. Furthermore, the principal abducens nucleus labeled heavily during conditioning. These findings suggest the feasibility of examining classical conditioning in a vertebrate in vitro brainstem-cerebellum preparation. It is postulated that the abducens nerve CR represents a behavioral correlate of a blink-related eye movement. Multiple sites of conditioning are hypothesized, including the cerebellorubral circuitry and brainstem pathways that activate the principal abducens nucleus.

  11. Classic conditioning of the ventilatory responses in rats.

    Science.gov (United States)

    Nsegbe, E; Vardon, G; Perruchet, P; Gallego, J

    1997-10-01

    Recent authors have stressed the role of conditioning in the control of breathing, but experimental evidence of this role is still sparse and contradictory. To establish that classic conditioning of the ventilatory responses can occur in rats, we performed a controlled experiment in which a 1-min tone [conditioned stimulus (CS)] was paired with a hypercapnic stimulus [8.5% CO2, unconditioned stimulus (US)]. The experimental group (n = 9) received five paired CS-US presentations, followed by one CS alone to test conditioning. This sequence was repeated six times. The control group (n = 7) received the same number of CS and US, but each US was delivered 3 min after the CS. We observed that after the CS alone, breath duration was significantly longer in the experimental than in the control group and mean ventilation was significantly lower, thus showing inhibitory conditioning. This conditioning may have resulted from the association between the CS and the inhibitory and aversive effects of CO2. The present results confirmed the high sensitivity of the respiratory controller to conditioning processes.

  12. Classical and quantum initial conditions for Higgs inflation

    Directory of Open Access Journals (Sweden)

    Alberto Salvio

    2015-11-01

    Full Text Available We investigate whether Higgs inflation can occur in the Standard Model starting from natural initial conditions or not. The Higgs has a non-minimal coupling to the Ricci scalar. We confine our attention to the regime where quantum Einstein gravity effects are small in order to have results that are independent of the ultraviolet completion of gravity. At the classical level we find no tuning is required to have successful Higgs inflation, provided the initial homogeneity condition is satisfied. On the other hand, at the quantum level we obtain that the renormalization for large non-minimal coupling requires an additional degree of freedom, unless a tuning of the initial values of the running parameters is made. In order to see that this effect may change the predictions we finally include such degree of freedom in the field content and show that Starobinsky's R2 inflation dominates over Higgs inflation.

  13. Eyeblink classical conditioning differentiates normal aging from Alzheimer's disease.

    Science.gov (United States)

    Woodruff-Pak, D S

    2001-01-01

    Eyeblink classical conditioning is a useful paradigm for the study of the neurobiology of learning, memory, and aging, which also has application in the differential diagnosis of neurodegenerative diseases expressed in advancing age. Converging evidence from studies of eyeblink conditioning in neurological patients and brain imaging in normal adults document parallels in the neural substrates of this form of associative learning in humans and non-human mammals. Age differences in the short-delay procedure (400 ms CS-US interval) appear in middle age in humans and may be caused at least in part by cerebellar cortical changes such as loss of Purkinje cells. Whereas the hippocampus is not essential for conditioning in the delay procedure, disruption of hippocampal cholinergic neurotransmission impairs acquisition and slows the rate of learning. Alzheimer's disease (AD) profoundly disrupts the hippocampaL cholinergic system, and patients with AD consistently perform poorly in eyeblink conditioning. We hypothesize that disruption of hippocampal cholinergic pathways in AD in addition to age-associated Purkinje cell loss results in severely impaired eyeblink conditioning. The earliest pathology in AD occurs in entorhinal cortical input to hippocampus, and eyeblink conditioning may detect this early disruption before declarative learning and memory circuits become impaired. A case study is presented in which eyeblink conditioning detected impending dementia six years before changes on other screening tests indicated impairment. Because eyeblink conditioning is simple, non-threatening, and non-invasive, it may become a useful addition to test batteries designed to differentiate normal aging from mild cognitive impairment that progresses to AD and AD from other types of dementia.

  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. CLASSICAL CONDITIONING OF THREE KINDS OF HUMOR IN PUBLICITY

    Directory of Open Access Journals (Sweden)

    CAROLINA M. CIFUENTES

    2006-01-01

    Full Text Available Effects of humor in advertisement published in Colombia were investigated in regards to brands,advertisement, purchase intention, recall and recognition.A simultaneous Classical Conditioning procedure was carried out, using Incongruous, Hostile and Allusivehumor associated to three brands. The procedure was applied to 30 university students. Results revealedthat the three kinds of humor work as unconditioning stimulus, generating positive attitudes towardsadvertisement and brand. Humor influences the purchase intention and recognition, but not the remembranceof brand when compared to neutral advertisement. Incongrous and Hostile Humor generate recognitionand positive attitude towards advertisement and brand. Allusions have a greater effect on purchaseintention than the other ones. Results corroborate the effectiveness of humor as an advertisement tool.

  16. Buchert coarse-graining and the classical energy conditions

    CERN Document Server

    Visser, Matt

    2015-01-01

    So-called "Buchert averaging" is actually a coarse-graining procedure, where fine detail is "smeared out" due to limited spatio-temporal resolution. For technical reasons, (to be explained herein), "averaging" is not really an appropriate term, and I shall consistently describe the process as a "coarse-graining". Because Einstein gravity is nonlinear the coarse-grained Einstein tensor is typically not equal to the Einstein tensor of the coarse-grained spacetime geometry. The discrepancy can be viewed as an "effective" stress-energy, and this "effective" stress-energy often violates the classical energy conditions. To keep otherwise messy technical issues firmly under control, I shall work with conformal-FLRW (CFLRW) cosmologies. These CFLRW-based models are particularly tractable, and are also particularly attractive observationally: the CMB is not distorted. In this CFLRW context one can prove some rigorous theorems regarding the interplay between Buchert coarse-graining, tracelessness of the effective stres...

  17. Preparing for an Important Event: Demonstrating the Modern View of Classical Conditioning.

    Science.gov (United States)

    Kohn, Art; Kalat, James W.

    1992-01-01

    Explains a simple classroom demonstration of the modern view of classical conditioning. Suggests that the exercise is a useful demonstration of the view that classical conditioning helps prepare an organism for an upcoming event. Argues that the demonstration can show students that classical conditioning is broader and more intriguing than…

  18. Classic conditioning in aged rabbits: delay, trace, and long-delay conditioning.

    Science.gov (United States)

    Solomon, P R; Groccia-Ellison, M E

    1996-06-01

    Young (0.5 years) and aged (2+, 3+, and 4+ years) rabbits underwent acquisition of the classically conditioned nictitating membrane response in a delay (500-ms conditioned stimulus [CS], 400-ms interstimulus interval [ISI]), long-delay (1,000-ms CS, 900-ms ISI), or trace (500-ms CS, 400-ms stimulus-free period) paradigm. Collapsing across age groups, there is a general tendency for animals to acquire trace conditioning more slowly than delay conditioning. Collapsing across conditioning paradigms, there is a general tendency for aged animals to acquire more slowly than younger animals. Of greater significance, however, are the age differences in the different conditioning paradigms. In the delay and long-delay paradigms, significant conditioning deficits first appeared in the 4(+)-year-old group. In the trace conditioning paradigm, significant conditioning deficits became apparent in the 2(+)-year-old animals.

  19. Conditioned withdrawal in goldfish: a simple and inexpensive preparation for the study of classical fear conditioning in vertebrates.

    Science.gov (United States)

    Barela, Peter B

    2012-02-01

    Summary.-A preparation for the study of classical fear conditioning in vertebrates is described. Its unique features are that it is inexpensive and easy to construct and operate. The following classical conditioning phenomena are demonstrated using this preparation: excitatory conditioning, extinction, contextual conditioning, blocking, a conditioned inhibition discrimination, and latent inhibition.

  20. Eyeblink Classical Conditioning in Alcoholism and Fetal Alcohol Spectrum Disorders.

    Science.gov (United States)

    Cheng, Dominic T; Jacobson, Sandra W; Jacobson, Joseph L; Molteno, Christopher D; Stanton, Mark E; Desmond, John E

    2015-01-01

    Alcoholism is a debilitating disorder that can take a significant toll on health and professional and personal relationships. Excessive alcohol consumption can have a serious impact on both drinkers and developing fetuses, leading to long-term learning impairments. Decades of research in laboratory animals and humans have demonstrated the value of eyeblink classical conditioning (EBC) as a well-characterized model system to study the neural mechanisms underlying associative learning. Behavioral EBC studies in adults with alcohol use disorders and in children with fetal alcohol spectrum disorders report a clear learning deficit in these two patient populations, suggesting alcohol-related damage to the cerebellum and associated structures. Insight into the neural mechanisms underlying these learning impairments has largely stemmed from laboratory animal studies. In this mini-review, we present and discuss exemplary animal findings and data from patient and neuroimaging studies. An improved understanding of the neural mechanisms underlying learning deficits in EBC related to alcoholism and prenatal alcohol exposure has the potential to advance the diagnoses, treatment, and prevention of these and other pediatric and adult disorders.

  1. Effects of Different Sera Conditions on Olfactory Ensheathing Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Meng Lu

    2014-12-01

    Full Text Available Transplantation of olfactory ensheathing cells (OEC is a promising therapy in spinal cord injury (SCI treatment. However, the therapeutic efficacy of this method is unstable due to unknown reasons. Considering the alterations in the culture environment that occur during OEC preparation for transplantation, we hypothesize that these changes may cause variations in the curative effects of this method. In this study, we compared OEC cultured in medium containing different types and concentrations of serum. After purification and passage, the OEC were cultured for 7 days in different media containing 5%, 10%, 15% or 20% fetal bovine serum (FBS or rat serum (RS, or the cells were cultured in FBS-containing medium first, followed by medium containing RS. In another group, the OEC were first cultured in 10% FBS for 3 days and then cultured with rat spinal cord explants with 10% RS for another 4 days. An MTT assay and P75 neurotrophin receptor immunofluorescence staining were used to examine cell viability and OEC numbers, respectively. The concentration of neurotrophin-3 (NT-3, which is secreted by OEC into the culture supernatant, was detected using the enzyme-linked immunosorbent assay (ELISA. RT-PCR was applied to investigate the NT-3 gene expression in OEC according to different groups. Compared with FBS, RS reduced OEC proliferation in relation to OEC counts (χ2 = 166.279, df = 1, p < 0.01, the optical density (OD value in the MTT assay (χ2 = 34.730, df = 1, p < 0.01, and NT-3 concentration in the supernatant (χ2 = 242.997, df = 1, p < 0.01. OEC cultured with spinal cord explants secreted less NT-3 than OEC cultured alone (F = 9.611, df = 5.139, p < 0.01. Meanwhile, the order of application of different sera was not influential. There was statistically significant difference in NT-3 gene expression among different groups when the serum concentration was 15% (χ2 = 64.347, df = 1, p < 0.01. In conclusion, different serum conditions may be

  2. Odor discrimination in classical conditioning of proboscis extension in two stingless bee species in comparison to Africanized honeybees.

    Science.gov (United States)

    Mc Cabe, S I; Hartfelder, K; Santana, W C; Farina, W M

    2007-11-01

    Learning in insects has been extensively studied using different experimental approaches. One of them, the proboscis extension response (PER) paradigm, is particularly well suited for quantitative studies of cognitive abilities of honeybees under controlled conditions. The goal of this study was to analyze the capability of three eusocial bee species to be olfactory conditioned in the PER paradigm. We worked with two Brazilian stingless bees species, Melipona quadrifasciata and Scaptotrigona aff. depilis, and with the invasive Africanized honeybee, Apis mellifera. These three species present very different recruitment strategies, which could be related with different odor-learning abilities. We evaluated their gustatory responsiveness and learning capability to discriminate floral odors. Gustatory responsiveness was similar for the three species, although S. aff. depilis workers showed fluctuations along the experimental period. Results for the learning assays revealed that M. quadrifasciata workers can be conditioned to discriminate floral odors in a classical differential conditioning protocol and that this discrimination is maintained 15 min after training. During conditioning, Africanized honeybees presented the highest discrimination, for M. quadrifasciata it was intermediate, and S. aff. depilis bees presented no discrimination. The differences found are discussed considering the putative different learning abilities and procedure effect for each species.

  3. Olfactory conditioning in the third instar larvae of Drosophila melanogaster using heat shock reinforcement.

    Science.gov (United States)

    Khurana, Sukant; Robinson, Brooks G; Wang, Zihe; Shropshire, William C; Zhong, Allen C; Garcia, Laura E; Corpuz, Jonathan; Chow, Jonathan; Hatch, Michael M; Precise, Eric F; Cady, Amanda; Godinez, Ryan M; Pulpanyawong, Terapat; Nguyen, Andrew T; Li, Wen-Ke; Seiter, Max; Jahanian, Kambiz; Sun, Jeffrey C; Shah, Ruchita; Rajani, Sunaina; Chen, William Y; Ray, Sofia; Ryazanova, Natalie V; Wakou, Dorah; Prabhu, Rohith K; Atkinson, Nigel S

    2012-01-01

    Adult Drosophila melanogaster has long been a popular model for learning and memory studies. Now the larval stage of the fruit fly is also being used in an increasing number of classical conditioning studies. In this study, we employed heat shock as a novel negative reinforcement for larvae and obtained high learning scores following just one training trial. We demonstrated heat-shock conditioning in both reciprocal and non-reciprocal paradigms and observed that the time window of association for the odor and heat shock reinforcement is on the order of a few minutes. This is slightly wider than the time window for electroshock conditioning reported in previous studies, possibly due to lingering effects of the high temperature. To test the utility of this simplified assay for the identification of new mutations that disrupt learning, we examined flies carrying mutations in the dnc gene. While the sensitivity to heat shock, as tested by writhing, was similar for wild type and dnc homozygotes, dnc mutations strongly diminished learning. We confirmed that the learning defect in dnc flies was indeed due to mutation in the dnc gene using non-complementation analysis. Given that heat shock has not been employed as a reinforcement for larvae in the past, we explored learning as a function of heat shock intensity and found that optimal learning occurred around 41 °C, with higher and lower temperatures both resulting in lower learning scores. In summary, we have developed a very simple, robust paradigm of learning in fruit fly larvae using heat shock reinforcement.

  4. 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.

  5. Colocalization of allatotropin and tachykinin-related peptides with classical transmitters in physiologically distinct subtypes of olfactory local interneurons in the cockroach (Periplaneta americana).

    Science.gov (United States)

    Fusca, Debora; Schachtner, Joachim; Kloppenburg, Peter

    2015-07-01

    In the insect antennal lobe different types of local interneurons mediate complex excitatory and inhibitory interactions between the glomerular pathways to structure the spatiotemporal representation of odors. Mass spectrometric and immunohistochemical studies have shown that in local interneurons classical neurotransmitters are likely to colocalize with a variety of substances that can potentially act as cotransmitters or neuromodulators. In the antennal lobe of the cockroach Periplaneta americana, gamma-aminobutyric acid (GABA) has been identified as the potential inhibitory transmitter of spiking type I local interneurons, whereas acetylcholine is most likely the excitatory transmitter of nonspiking type IIa1 local interneurons. This study used whole-cell patch clamp recordings combined with single-cell labeling and immunohistochemistry to test if the GABAergic type I local interneurons and the cholinergic type IIa1 local interneurons express allatotropin and tachykinin-related neuropeptides (TKRPs). These are two of the most abundant types of peptides in the insect antennal lobe. GABA-like and choline acetyltransferase (ChAT)-like immunoreactivity were used as markers for GABAergic and cholinergic neurons, respectively. About 50% of the GABA-like immunoreactive (-lir) spiking type I local interneurons were allatotropin-lir, and ∼ 40% of these neurons were TKRP-lir. About 20% of nonspiking ChAT-lir type IIa1 local interneurons were TKRP-lir. Our results suggest that in subpopulations of GABAergic and cholinergic local interneurons, allatotropin and TKRPs might act as cotransmitters or neuromodulators. To unequivocally assign neurotransmitters, cotransmitters, and neuromodulators to identified classes of antennal lobe neurons is an important step to deepen our understanding of information processing in the insect olfactory system.

  6. A Classical Conditioning Procedure for the Hearing Assessment of Multiply Handicapped Persons.

    Science.gov (United States)

    Lancioni, Giulio E.; And Others

    1989-01-01

    Hearing assessments of multiply handicapped children/adolescents were conducted using classical conditioning (with an air puff as unconditioned stimulus) and operant conditioning (with a modified visual reinforcement audiometry procedure or edible reinforcement). Findings indicate that classical conditioning was successful with 21 of the 23…

  7. Exploratory studies of classical conditioning of the preoral cavity in harnessed carpenter ants (Camponotus pennsylvanicus).

    Science.gov (United States)

    Sauer, Dustin L; Abramson, Charles I; Lawson, Adam L

    2002-06-01

    An attempt was made to classically condition the mouthparts of harnessed worker ants (Camponotus pennsylvanicus) in anticipation of feeding. Experiments were designed to investigate classical conditioning with one CS, discrimination between two CSs, and pseudoconditioning. Analysis indicated a small acquisition effect that could be accounted for by pseudoconditioning. The preparation can be used to study nonassociative learning and some instrumental conditioning situations.

  8. Extending In Vitro Conditioning in "Aplysia" to Analyze Operant and Classical Processes in the Same Preparation

    Science.gov (United States)

    Brembs, Bjorn; Baxter, Douglas A.; Byrne, John H.

    2004-01-01

    Operant and classical conditioning are major processes shaping behavioral responses in all animals. Although the understanding of the mechanisms of classical conditioning has expanded significantly, the understanding of the mechanisms of operant conditioning is more limited. Recent developments in "Aplysia" are helping to narrow the gap in the…

  9. Unconscious classical conditioning of sexual arousal: Evidence for the conditioning of female genital arousal to subliminally presented sexual stimuli

    NARCIS (Netherlands)

    S. Both; M. Spiering; E. Laan; S. Balcome; B. van den Heuvel; W. Everaerd

    2008-01-01

    Introduction. Although the assumption that sexual behavior is at least partly learned is common across theories of sexual behavior, classical conditioning of sexual response in women has been seldom studied. Aim. The study of unconscious classical conditioning of appetitive sexual responses in women

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

    Science.gov (United States)

    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.

  11. An implicit measure of olfactory performance for non-human primates reveals aversive and pleasant odor conditioning.

    Science.gov (United States)

    Livneh, Uri; Paz, Rony

    2010-09-30

    We have little understanding of how odorants are processed in neural networks of the primate brain. Because chemo-stimuli are harder to control than physical stimuli (e.g. vision, audition), such research was limited by the temporal resolution, accuracy, and reliability of olfactometers (odor producing machines). Recent advances were able to create olfactometers that overcome these limitations, allowing their use together with neuroimaging techniques in humans. From the behavioral point of view, olfaction research requires a behavioral measure that can be used to quantify olfactory performance. This becomes a real problem when working with animals, where, unlike humans, explicit measures are harder to obtain. Furthermore, because odorants are powerful primitive reinforcers, such implicit measures can be beneficial to use in learning paradigms. Here we describe an olfactometer suitable for use in non-human primates, and an end-port design that allows the accurate measure of real-time respiratory modulations that are elicited in response to odor presentation. We demonstrate that this implicit measure is differentially modulated when experiencing pleasant or aversive odors. We then present an experimental paradigm in which monkeys learn to associate tones with odors, and show that the time delay from the conditioned stimuli to the next breath can be used to measure learning and memory expression in this paradigm. Using this construct, we reveal olfactory performance during acquisition and extinction of odor conditioning. These techniques can be used in electrophysiological recordings from relevant brain areas to shed light on neural networks involved in odor processing and reinforcement-learning.

  12. Using powerpoint to demonstrate human classical salivary conditioning in a classroom situation.

    Science.gov (United States)

    Abramson, Charles I; Brown, Erika A; Langley, Dillon

    2011-02-01

    Classical conditioning is one of the most fundamental types of learning, yet demonstrating its principles in a classroom setting can be challenging. This study introduces using PowerPoint as a new, practical technique that can be used in a classroom setting to demonstrate classical conditioning. The PowerPoint file is flexible and easy to adapt for demonstrating various aspects of classical conditioning (including higher order conditioning) in a concrete manner. Moreover, this study was designed to measure salivation in a more objective and valid way which could be used by student researchers interested in measuring salivation as a conditioned response.

  13. 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...

  14. Demonstrating Classical Conditioning in Introductory Psychology: Needles Do Not Always Make Balloons Pop!

    Science.gov (United States)

    Vernoy, Mark W.

    1987-01-01

    Describes a method of teaching classical conditioning to an introductory psychology class which involves demonstrating the conditioned response that occurs when a needle pierces, but does not pop, a balloon. (GEA)

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Ken Tan

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

  17. Classical Conditioning of Hippocampal Theta Patterns in the Rat.

    Science.gov (United States)

    1976-08-01

    associated with changes in performance of learned tasks , 1,4,5, 8,9 there have been very few studies of neurona l plasticity of the hippocampus It self...rapid development of a conditioned hippocampal theta response to a visual sti mulus demonstrates tha t there is considerable neurona l plasticity in the

  18. Conditional Similarity Reductions of Jimbo-Miwa Equation via the Classical Lie Group Approach

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao-Yan; LIN Ji

    2003-01-01

    Recently, the Clarkson and Kruskal direct method has been modified to find new similarity reductions (conditional similarity reductions) of nonlinear systems and the results obtained by the modified direct method cannot be obtained by the current classical and/or non-classical Lie group approach. In this paper, we show that the conditional similarity reductions of the Jimbo-Miwa equation can be reobtained by adding an additional constraint equation to the original model to form a conditional equation system first and then solving the model system by means of the classical Lie group approach.

  19. The Operant and the Classical in Conditioned Orientation of Drosophila melanogaster at the Flight Simulator

    Science.gov (United States)

    Brembs, Björn; Heisenberg, Martin

    2000-01-01

    Ever since learning and memory have been studied experimentally, the relationship between operant and classical conditioning has been controversial. Operant conditioning is any form of conditioning that essentially depends on the animal's behavior. It relies on operant behavior. A motor output is called operant if it controls a sensory variable. The Drosophila flight simulator, in which the relevant behavior is a single motor variable (yaw torque), fully separates the operant and classical components of a complex conditioning task. In this paradigm a tethered fly learns, operantly or classically, to prefer and avoid certain flight orientations in relation to the surrounding panorama. Yaw torque is recorded and, in the operant mode, controls the panorama. Using a yoked control, we show that classical pattern learning necessitates more extensive training than operant pattern learning. We compare in detail the microstructure of yaw torque after classical and operant training but find no evidence for acquired behavioral traits after operant conditioning that might explain this difference. We therefore conclude that the operant behavior has a facilitating effect on the classical training. In addition, we show that an operantly learned stimulus is successfully transferred from the behavior of the training to a different behavior. This result unequivocally demonstrates that during operant conditioning classical associations can be formed. PMID:10753977

  20. Olfactory conditioning of the sting extension reflex in honeybees: Memory dependence on trial number, interstimulus interval, intertrial interval, and protein synthesis.

    Science.gov (United States)

    Giurfa, Martin; Fabre, Eve; Flaven-Pouchon, Justin; Groll, Helga; Oberwallner, Barbara; Vergoz, Vanina; Roussel, Edith; Sandoz, Jean Christophe

    2009-12-01

    Harnessed bees learn to associate an odorant with an electric shock so that afterward the odorant alone elicits the sting extension response (SER). We studied the dependency of retention on interstimulus interval (ISI), intertrial interval (ITI), and number of conditioning trials in the framework of olfactory SER conditioning. Forward ISIs (conditioned stimulus [CS] before unconditioned stimulus [US]) supported higher retention than a backward one (US before CS) with an optimum around 3 sec. Spaced trials (ITI 10 min) supported higher retention than massed trials (ITI 1 min) and led to the formation of a late long-term memory (l-LTM) that depended on protein synthesis. Our results reaffirm olfactory SER conditioning as a reliable tool for the study of learning and memory.

  1. Electrophysiological characterisation of human umbilical cord blood-derived mesenchymal stem cells induced by olfactory ensheathing cell-conditioned medium.

    Science.gov (United States)

    Zeng, Yu; Rong, Mingqiang; Liu, Yunsheng; Liu, Jingfang; Lu, Ming; Tao, Xiaoyu; Li, Zhenyan; Chen, Xin; Yang, Kui; Li, Chuntao; Liu, Zhixiong

    2013-12-01

    Umbilical cord blood-derived marrow stromal cells (UCB-MSCs) with high proliferation capacity and immunomodulatory properties are considered to be a good candidate for cell-based therapies. But until now, little work has been focused on the differentiation of UCB-MSCs. In this work, UCB-MSCs were demonstrated to be negative for CD34 and CD45 expression but positive for CD90 and CD105 expression. The gate values of UCB-MSCs for CD90 and CD105 were 99.3 and 98.6 %, respectively. Two weeks after treatment, the percentage of neuron-like cells differentiated from UCB-MSCs was increased to 84 ± 12 % in the experimental group [treated with olfactory ensheathing cells (OECs)-conditioned medium] and they were neuron-specific enolase positive; few neuron-like cells were found in the control group (without OECs-conditioned medium). Using whole-cell recording, sodium and potassium currents were recorded in UCB-MSCs after differentiation by OECs. Thus, human UCB-MSCs could be differentiated to neural cells by secreted secretion from OECs and exhibited electrophysiological properties similar to mature neurons after 2 weeks post-induction. These results imply that OECs can be used as a new strategy for stem cell differentiation and provide an alternative neurogenesis pathway for generating sufficient numbers of neural cells for cell therapy.

  2. Classical Conditioning of Eyelid and Mystacial Vibrissae Responses in Conscious Mice

    Science.gov (United States)

    Delgado-Garcia, Jose Maria; Troncoso, Julieta; Munera, Alejandro

    2004-01-01

    The murine vibrissae sensorimotor system has been scrutinized as a target of motor learning through trace classical conditioning. Conditioned eyelid responses were acquired by using weak electrical whisker-pad stimulation as conditioned stimulus (CS) and strong electrical periorbital stimulation as unconditioned stimulus (US). In addition,…

  3. Effects of local anesthesia of the cerebellum on classical fear conditioning in goldfish

    Directory of Open Access Journals (Sweden)

    Hirano Ruriko

    2010-03-01

    Full Text Available Abstract Background Besides the amygdala, of which emotion roles have been intensively studied, the cerebellum has also been demonstrated to play a critical role in simple classical fear conditioning in both mammals and fishes. In the present study, we examined the effect of local administration of the anesthetic agent lidocaine into the cerebellum on fear-related, classical heart-rate conditioning in goldfish. Methods The effects of microinjection of the anesthetic agent lidocaine into the cerebellum on fear conditioning were investigated in goldfish. The fear conditioning paradigm was delayed classical conditioning with light as a conditioned stimulus and electric shock as an unconditioned stimulus; cardiac deceleration (bradycardia was the conditioned response. Results Injecting lidocaine into the cerebellum had no effect on the base heart rate, an arousal/orienting response to the novel stimulus (i.e., the first presentation of light, or an unconditioned response to electric shock. However, lidocaine injection greatly impaired acquisition of conditioned bradycardia. Lidocaine injection 60 min before the start of the conditioning procedure showed no effect on acquisition of conditioned bradycardia, indicating that the effect of lidocaine was reversible. Conclusions The present results further confirm the idea that the cerebellum in teleost fish, as in mammals, is critically involved in classical fear conditioning.

  4. The scent of salience--is there olfactory-trigeminal conditioning in humans?

    Science.gov (United States)

    Moessnang, C; Pauly, K; Kellermann, T; Krämer, J; Finkelmeyer, A; Hummel, T; Siegel, S J; Schneider, F; Habel, U

    2013-08-15

    Pavlovian fear conditioning has been thoroughly studied in the visual, auditory and somatosensory domain, but evidence is scarce with regard to the chemosensory modality. Under the assumption that Pavlovian conditioning relies on the supra-modal mechanism of salience attribution, the present study was set out to attest the existence of chemosensory aversive conditioning in humans as a specific instance of salience attribution. fMRI was performed in 29 healthy subjects during a differential aversive conditioning paradigm. Two odors (rose, vanillin) served as conditioned stimuli (CS), one of which (CS+) was intermittently coupled with intranasally administered CO2. On the neural level, a robust differential response to the CS+ emerged in frontal, temporal, occipito-parietal and subcortical brain regions, including the amygdala. These changes were paralleled by the development of a CS+-specific connectivity profile of the anterior midcingulate cortex (aMCC), which is a key structure for processing salience information in order to guide adaptive response selection. Increased coupling could be found between key nodes of the salience network (anterior insula, neo-cerebellum) and sensorimotor areas, representing putative input and output structures of the aMCC for exerting adaptive motor control. In contrast, behavioral and skin conductance responses did not show significant effects of conditioning, which has been attributed to contingency unawareness. These findings imply substantial similarities of conditioning involving chemosensory and other sensory modalities, and suggest that salience attribution and adaptive control represent a general, modality-independent principle underlying Pavlovian conditioning.

  5. 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.

  6. Studies in Early Infant Learning: Classical Conditioning of the Neonatal Heart Rate

    Science.gov (United States)

    Crowell, David H.; And Others

    1976-01-01

    In three experiments, it was demonstrated that human newborn heart rate level can be reliably modified through classical conditioning procedures. Findings support the idea that early learning may occur under a variety of conditions and different theories may account for the results. (Author/SB)

  7. Classical Conditioning and Retention of the Infant's Eyelid Response: Effects of Age and Interstimulus Interval.

    Science.gov (United States)

    Little, Arlene H.; And Others

    1984-01-01

    Reports that lengthy interstimulus interval facilitates classical conditioning in very young infants. Infants trained in a single session at 20 days of age exhibited reliable retention of the conditioned eyelid reflex 10 days later, but infants 10 days of age did not. (Author)

  8. Feeding Behavior of Aplysia: A Model System for Comparing Cellular Mechanisms of Classical and Operant Conditioning

    Science.gov (United States)

    Baxter, Douglas A.; Byrne, John H.

    2006-01-01

    Feeding behavior of Aplysia provides an excellent model system for analyzing and comparing mechanisms underlying appetitive classical conditioning and reward operant conditioning. Behavioral protocols have been developed for both forms of associative learning, both of which increase the occurrence of biting following training. Because the neural…

  9. A Neutral Odor May Become a Sexual Incentive through Classical Conditioning in Male Rats

    Science.gov (United States)

    Kvitvik, Inger-Line; Berg, Kristine Marit; Agmo, Anders

    2010-01-01

    A neutral olfactory stimulus was employed as CS in a series of experiments with a sexually receptive female as UCS and the execution of an intromission as the UCR. Each experimental session lasted until the male ejaculated. The time the experimental subject spent in a zone adjacent to the source of the olfactory stimulus during the 10 s of CS…

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Quantum versus classical foundation of statistical mechanics under experimentally realistic conditions.

    Science.gov (United States)

    Reimann, Peter; Evstigneev, Mykhaylo

    2013-11-01

    Focusing on isolated macroscopic systems, described in terms of either a quantum mechanical or a classical model, our two key questions are how far does an initial ensemble (usually far from equilibrium and largely unknown in detail) evolve towards a stationary long-time behavior (equilibration) and how far is this steady state in agreement with the microcanonical ensemble as predicted by statistical mechanics (thermalization). A recently developed quantum mechanical treatment of the problem is briefly summarized, putting particular emphasis on the realistic modeling of experimental measurements and nonequilibrium initial conditions. Within this framework, equilibration can be proven under very weak assumptions about those measurements and initial conditions, while thermalization still requires quite strong additional hypotheses. An analogous approach within the framework of classical mechanics is developed and compared with the quantum case. In particular, the assumptions to guarantee classical equilibration are now rather strong, while thermalization then follows under relatively weak additional conditions.

  12. Special issue on computational models of classical conditioning guest editors' introduction.

    Science.gov (United States)

    Alonso, Eduardo; Schmajuk, Nestor

    2012-09-01

    In the present special issue, the performance of current computational models of classical conditioning was evaluated under three requirements: (1) Models were to be tested against a list of previously agreed-upon phenomena; (2) the parameters were fixed across simulations; and (3) the simulations used to test the models had to be made available. These requirements resulted in three major products: (a) a list of fundamental classical-conditioning results for which there is a consensus about their reliability; (b) the necessary information to evaluate each of the models on the basis of its ordinal successes in accounting for the experimental data; and (c) a repository of computational models ready to generate simulations. We believe that the contents of this issue represent the 2012 state of the art in computational modeling of classical conditioning and provide a way to find promising avenues for future model development.

  13. Sea slugs, subliminal pictures and vegetative state patients: Boundaries of consciousness in classical conditioning.

    Directory of Open Access Journals (Sweden)

    Tristan A Bekinschtein

    2011-12-01

    Full Text Available Classical (trace conditioning is a specific variant of associative learning in which a neutral stimulus leads to the subsequent prediction of an emotionally charged or noxious stimulus after a temporal gap. When conditioning is concurrent with a distraction task, only participants who can report the relationship (the contingency between stimuli explicitly show associative learning. This suggests that consciousness is a prerequisite for trace conditioning. We review and question three main controversies concerning this view. Firstly, virtually all animals, even invertebrate sea slugs, show this type of learning; secondly, unconsciously perceived stimuli may elicit trace conditioning; and thirdly, some vegetative state patients show trace learning. We discuss and analyze these seemingly contradictory arguments to find the theoretical boundaries of consciousness in classical conditioning. We conclude that trace conditioning remains one of the best measures to test conscious processing in the absence of explicit reports.

  14. 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.

  15. Investigating the non-classical boundary conditions relevant to strain gradient theories

    Science.gov (United States)

    Jafari, Akbar; Ezzati, Meysam

    2017-02-01

    In the present study, two classes of non-classical constitutive equations consisting of the first and the second order strain gradients theories (FSG and SSG) were applied in order to develop the governing equations of static and free vibrational behavior of beam structures. The governing equations in orders of six and eight were constructed for FSG and SSG theories, respectively. Therefore, higher order or in other words non-classical boundary conditions (HOBCs or NCBCs) came into play in addition to the classical ones (CBCs). Some explanations were presented about the concept of the non-classical boundary conditions. Analytical and finite element (FE) approaches were employed to solve the governing equations. The analytical solutions were utilized in validation and convergence study of FE results. Comparisons were made with the relevant data reported in the open literature; however, to the best of the authors' knowledge, few references have been published on SSG theory and HOBCs. In the numerical studies, the effects of applying different combinations of CBCs and HOBCs to the static and free vibration behaviors of the beam were investigated. Moreover, the impacts of non-classical elastic constants and the beam size on its behavior were also studied.

  16. Classical Conditioning of Emotional Responses (Meaning, Attitudes, Values, Interests) and Effects on Social Behavior: A Bibliography.

    Science.gov (United States)

    Staats, Arthur W.; Carlson, Carl G.

    This is a bibliography of 81 papers and books published in the years 1957-1970 relevant to the subject of verbally-elicited responses that are in accordance with principles of classical conditioning. Of these publications, 24 are by Staats--one of the bibliographers--and his associates. (MF)

  17. Spike-coding mechanisms of cerebellar temporal processing in classical conditioning and voluntary movements.

    Science.gov (United States)

    Yamaguchi, Kenji; Sakurai, Yoshio

    2014-10-01

    Time is a fundamental and critical factor in daily life. Millisecond timing, which is the underlying temporal processing for speaking, dancing, and other activities, is reported to rely on the cerebellum. In this review, we discuss the cerebellar spike-coding mechanisms for temporal processing. Although the contribution of the cerebellum to both classical conditioning and voluntary movements is well known, the difference of the mechanisms for temporal processing between classical conditioning and voluntary movements is not clear. Therefore, we review the evidence of cerebellar temporal processing in studies of classical conditioning and voluntary movements and report the similarities and differences between them. From some studies, which used tasks that can change some of the temporal properties (e.g., the duration of interstimulus intervals) with keeping identical movements, we concluded that classical conditioning and voluntary movements may share a common spike-coding mechanism because simple spikes in Purkinje cells decrease at predicted times for responses regardless of the intervals between responses or stimulation.

  18. Cholinergic Septo-Hippocampal Innervation Is Required for Trace Eyeblink Classical Conditioning

    Science.gov (United States)

    Fontan-Lozano, Angela; Troncoso, Julieta; Munera, Alejandro; Carrion, Angel Manuel; Delgado-Garcia, Jose Maria

    2005-01-01

    We studied the effects of a selective lesion in rats, with 192-IgG-saporin, of the cholinergic neurons located in the medial septum/diagonal band (MSDB) complex on the acquisition of classical and instrumental conditioning paradigms. The MSDB lesion induced a marked deficit in the acquisition, but not in the retrieval, of eyeblink classical…

  19. Repeated Acquisitions and Extinctions in Classical Conditioning of the Rabbit Nictitating Membrane Response

    Science.gov (United States)

    Kehoe, E. James

    2006-01-01

    The rabbit nictitating membrane (NM) response underwent successive stages of acquisition and extinction training in both delay (Experiment 1) and trace (Experiment 2) classical conditioning. In both cases, successive acquisitions became progressively faster, although the largest, most reliable acceleration occurred between the first and second…

  20. Is disgust sensitive to classical conditioning as indexed by facial electromyography and behavioural responses?

    NARCIS (Netherlands)

    Borg, Charmaine; Bosman, Renske C; Engelhard, Iris; Olatunji, Bunmi O; de Jong, Peter J

    2015-01-01

    Earlier studies provided preliminary support for the role of classical conditioning as a pathway of disgust learning, yet this evidence has been limited to self-report. This study included facial electromyographical (EMG) measurements (corrugator and levator muscles) and a behavioural approach task

  1. Is disgust sensitive to classical conditioning as indexed by facial electromyography and behavioural responses?

    Science.gov (United States)

    Borg, Charmaine; Bosman, Renske C; Engelhard, Iris; Olatunji, Bunmi O; de Jong, Peter J

    2016-01-01

    Earlier studies provided preliminary support for the role of classical conditioning as a pathway of disgust learning, yet this evidence has been limited to self-report. This study included facial electromyographical (EMG) measurements (corrugator and levator muscles) and a behavioural approach task to assess participants' motivation-to-eat the actual food items (conditioned stimuli, CS). Food items served as CS and film excerpts of a woman vomiting served as unconditioned stimuli (US). Following acquisition the CS+ (neutral CS paired with US disgust) was rated as more disgusting and less positive. Notably, the conditioned response was transferred to the actual food items as evidenced by participants' reported lowered willingness-to-eat. Participants also showed heightened EMG activity in response to the CS+ which seemed driven by the corrugator indexing a global negative affect. These findings suggest that classical conditioning as a pathway of disgust learning can be reliably observed in subjective but not in disgust-specific physiological responding.

  2. Telomere shortening impairs regeneration of the olfactory epithelium in response to injury but not under homeostatic conditions.

    Directory of Open Access Journals (Sweden)

    Masami Watabe-Rudolph

    Full Text Available Atrophy of the olfactory epithelium (OE associated with impaired olfaction and dry nose represents one of the most common phenotypes of human aging. Impairment in regeneration of a functional olfactory epithelium can also occur in response to injury due to infection or nasal surgery. These complications occur more frequently in aged patients. Although age is the most unifying risk factor for atrophic changes and functional decline of the olfactory epithelium, little is known about molecular mechanisms that could influence maintenance and repair of the olfactory epithelium. Here, we analyzed the influence of telomere shortening (a basic mechanism of cellular aging on homeostasis and regenerative reserve in response to chemical induced injury of the OE in late generation telomere knockout mice (G3 mTerc(-/- with short telomeres compared to wild type mice (mTerc(+/+ with long telomeres. The study revealed no significant influence of telomere shortening on homeostatic maintenance of the OE during mouse aging. In contrast, the regenerative response to chemical induced injury of the OE was significantly impaired in G3 mTerc(-/- mice compared to mTerc(+/+ mice. Seven days after chemical induced damage, G3 mTerc(-/- mice exhibited significantly enlarged areas of persisting atrophy compared to mTerc(+/+ mice (p = 0.031. Telomere dysfunction was associated with impairments in cell proliferation in the regenerating epithelium. Deletion of the cell cycle inhibitor, Cdkn1a (p21 rescued defects in OE regeneration in telomere dysfunctional mice. Together, these data indicate that telomere shortening impairs the regenerative capacity of the OE by impairing cell cycle progression in a p21-dependent manner. These findings could be relevant for the impairment in OE function in elderly people.

  3. A behavioral stages model of classical (Pavlovian) conditioning: application to cognitive aging.

    Science.gov (United States)

    Powell, D A

    1999-01-01

    In the present article, it is argued that a five-stage sequential model of the behavioral and neurophysiological events that occur when organisms are exposed to signals predicting significant events suggests that classical conditioning produces multiple memory traces involving both excitatory and inhibitory processes. Further, these multiple brain structures and associated neurophysiological mechanisms are beginning to be understood; thus, using Pavlovian conditioning techniques to study aging and cognitive functions may provide insights into which brain structures or mechanisms are responsible for more general age-related declines in associative learning and memory. The evidence for this model is briefly reviewed and studies suggesting age-related effects on classical conditioning of various response systems are described within the context of the brain structures implicated by the model.

  4. Experimental challenges to theories of classical conditioning: application of an attentional model of storage and retrieval.

    Science.gov (United States)

    Schmajuk, Nestor A; Larrauri, José A

    2006-01-01

    Several studies have recently challenged the accuracy of traditional models of classical conditioning that account for some experimental data in terms of a storage deficit. Among other results, it has been reported that extinction of the blocking or overshadowing stimulus results in the recovery of the response to the blocked or overshadowed stimulus, backward blocking shows spontaneous recovery, extinction of the training context results in the recovery from latent inhibition, interposing a delay between conditioning and testing in latent inhibition increases latent inhibition, and latent inhibition antagonizes overshadowing. An existing neural network model of classical conditioning (N. A. Schmajuk, Y. Lam, & J. A. Gray, 1996), which includes an attentional mechanism controlling both storage and retrieval of associations, is able to quantitatively describe these results.

  5. Psychiatric Conditions in Parkinson Disease: A Comparison With Classical Psychiatric Disorders.

    Science.gov (United States)

    Buoli, Massimiliano; Caldiroli, Alice; Altamura, Alfredo Carlo

    2016-03-01

    Psychiatric conditions often complicate the outcome of patients affected by Parkinson disease (PD), but they differ from classical psychiatric disorders in terms of underlying biological mechanisms, clinical presentation, and treatment response. The purpose of the present review is to illustrate the biological and clinical aspects of psychiatric conditions associated with PD, with particular reference to the differences with respect to classical psychiatric disorders. A careful search of articles on main databases was performed in order to obtain a comprehensive review about the main psychiatric conditions associated with PD. A manual selection of the articles was then performed in order to consider only those articles that concerned with the topic of the review. Psychiatric conditions in patients with PD present substantial differences with respect to classical psychiatric disorders. Their clinical presentation does not align with the symptom profiles represented by Diagnostic and Statistical Manual for Mental Disorders and International Classification of Diseases. Furthermore, psychiatry treatment guidelines are of poor help in managing psychiatric symptoms of patients with PD. Specific diagnostic tools and treatment guidelines are needed to allow early diagnosis and adequate treatment of psychiatric conditions in comorbidity with PD.

  6. Differential Transcriptional Response to Nonassociative and Associative Components of Classical Fear Conditioning in the Amygdala and Hippocampus

    Science.gov (United States)

    Isiegas, Carolina; Stein, Joel; Hellman, Kevin; Hannenhalli, Sridhar; Abel, Ted; Keeley, Michael B.; Wood, Marcelo A.

    2006-01-01

    Classical fear conditioning requires the recognition of conditioned stimuli (CS) and the association of the CS with an aversive stimulus. We used Affymetrix oligonucleotide microarrays to characterize changes in gene expression compared to naive mice in both the amygdala and the hippocampus 30 min after classical fear conditioning and 30 min after…

  7. Conditional symmetries in axisymmetric quantum cosmologies with scalar ?elds and the fate of the classical singularities

    CERN Document Server

    Zampeli, Adamantia; Terzis, Petros A; Christodoulakis, T

    2015-01-01

    In this paper, the classical and quantum solutions of some axisymmetric cosmologies coupled to a massless scalar field are studied in the context of minisuperspace approximation. In these models, the singular nature of the Lagrangians entails a search for possible conditional symmetries. These have been proven to be the simultaneous conformal symmetries of the supermetric and the superpotential. The quantization is performed by adopting the Dirac proposal for constrained systems, i.e. promoting the first-class constraints to operators annihilating the wave function. To further enrich the approach, we follow \\cite{Christodoulakis:2012eg} and impose the operators related to the classical conditional symmetries on the wave function. These additional equations select particular solutions of the Wheeler-DeWitt equation. In order to gain some physical insight from the quantization of these cosmological systems, we perform a semiclassical analysis following the Bohmian approach to quantum theory. The generic result ...

  8. Rabbit cerebellar slice analysis of long-term depression and its role in classical conditioning.

    Science.gov (United States)

    Schreurs, B G; Alkon, D L

    1993-12-24

    Cerebellar long-term depression (LTD) has been proposed as a mechanism underlying classical conditioning of the rabbit nictitating membrane/eyelid response (NMR). However, LTD has only been obtained reliably when (1) cerebellar slices are bathed in GABA antagonists which abolish disynaptic inhibitory post synaptic potentials, and (2) the temporal sequence of stimulation used in slice or intact preparations is the opposite of that used in classical conditioning. Based on intradendritic Purkinje cell recordings obtained from rabbit cerebellar slices, we report that stimulation of climbing fibers and then parallel fibers in the presence of the GABA antagonist, bicuculline, produced significant depression of parallel fiber excitatory post synaptic potential (epsp) amplitude that continued to increase for at least 20 min after stimulation. However, application of the same stimulation protocol without GABA antagonists produced a brief depression of parallel fiber epsps that disappeared within minutes. Activation of parallel fibers and then climbing fibers in an order opposite to the LTD-producing sequence (i.e. a classical conditioning-like order) produced a brief depression that dissipated quickly. Stimulation of parallel fibers alone produced a small, slowly developing potentiation, but stimulation of parallel fibers during depolarization-induced local dendritic calcium spikes produced significant depression almost immediately which then declined slowly to more modest levels. Finally, stimulation of parallel fibers at frequencies used in in vivo parallel fiber-climbing fiber stimulation experiments (e.g. 100 Hz) produced an immediate and profound long-lasting epsp depression. The depression occurred, however, whether parallel and climbing fibers were stimulated separately (unpaired) or in a classical conditioning-like protocol (paired) where parallel fiber stimulation coterminated with climbing fiber stimulation (10 Hz).(ABSTRACT TRUNCATED AT 250 WORDS)

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

    Science.gov (United States)

    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.

  10. Classical conditioning of autonomic fear responses is independent of contingency awareness.

    Science.gov (United States)

    Schultz, Douglas H; Helmstetter, Fred J

    2010-10-01

    The role of contingency awareness in classical conditioning experiments using human subjects is currently under debate. This study took a novel approach to manipulating contingency awareness in a differential Pavlovian conditioning paradigm. Complex sine wave gratings were used as visual conditional stimuli (CS). By manipulating the fundamental spatial frequency of the displays, we were able to construct pairs of stimuli that varied in discriminability. One group of subjects was given an "easy" discrimination, and another was exposed to a "difficult" CS+ and CS-. A 3rd group was exposed to a stimulus that was paired with the unconditional stimulus (UCS) 50% of the time and served as a control. Skin conductance response (SCR) and continuous UCS expectancy data were measured concurrently throughout the experiment. Differential UCS expectancy was found only in the easy discrimination group. Differential SCRs were found in the easy discrimination group as well as in the difficult discrimination group, but not in the 50% contingency control. The difficult discrimination group did not exhibit differential UCS expectancy but did show clear differential SCR. These observations support a dual process interpretation of classical conditioning whereby conditioning on an implicit level can occur without explicit knowledge about the contingencies. The role of contingency awareness in classical conditioning experiments using human subjects is currently under debate. This study took a novel approach to manipulating contingency awareness in a differential Pavlovian conditioning paradigm. Complex sine wave gratings were used as visual conditional stimuli (CS). By manipulating the fundamental spatial frequency of the displays, we were able to construct pairs of stimuli that varied in discriminability. One group of subjects was given an "easy" discrimination, and another was exposed to a "difficult" CS+ and CS-. A 3rd group was exposed to a stimulus that was paired with the

  11. Transsynaptic EphB/Ephrin-B signaling regulates growth of presynaptic boutons required for classical conditioning.

    Science.gov (United States)

    Li, Wei; Zheng, Zhaoqing; Keifer, Joyce

    2011-06-01

    Learning-related presynaptic remodeling has been documented in only a few systems, and its molecular mechanisms are largely unknown. Here we describe a role for the bidirectional EphB/ephrin-B signaling system in structural plasticity of presynaptic nerve terminals using an in vitro model of classical conditioning. Conditioning or BDNF application induced significant growth of auditory nerve presynaptic boutons that convey the conditioned stimulus to abducens motor neurons. Interestingly, bouton enlargement occurred only for those synapses apposed to motor neuron dendrites rather than to somata. Phosphorylation of ephrin-B1, but not EphB2, was induced by both conditioning and BDNF application and was inhibited by postsynaptic injections of ephrin-B antibody. Finally, suppression of postsynaptic ephrin-B function inhibited presynaptic bouton enlargement that was rescued by activation of EphB2 by ephrin-B1-Fc. These data provide evidence for ephrin-B-induced EphB2 forward signaling in presynaptic structural plasticity during classical conditioning. They also reveal a functional interaction between BDNF/TrkB and the Eph/ephrin signaling systems in the coordination of presynaptic and postsynaptic modifications during conditioning.

  12. Omission of expected reward sensitizes the brain dopaminergic system of classically conditioned Atlantic salmon

    DEFF Research Database (Denmark)

    Vindas, M.A.; Höglund, Erik; Folkedal, O.

    in fishes. Here we show that the omission of expected reward (OER) leads to increased aggression towards conspecifics in classically conditioned Atlantic salmon (Salmo salar). Furthermore, in response to an acute stressor, OER fish displayed increased dopaminergic (DA) neurotransmission compared to controls....... There was also a general downregulation of dopamine receptor D1 gene expression in the telencephalon of OER groups, which suggests a coping mechanism in response to unbalanced DA metabolism. These results indicate that animals subjected to unpredictable reward conditions develop a senzitation of the DA...

  13. Psychology of the scientist: LXXXII. Coverage of classical conditioning in textbooks in the psychology of learning, 1952-1995.

    Science.gov (United States)

    Coleman, S R; Fanelli, A; Gedeon, S

    2000-06-01

    Objective information was obtained from 89 textbooks in the psychology of learning published from 1952 through 1995 to answer questions about their coverage of classical conditioning. We found (a) that classical conditioning consistently received less coverage than instrumental and operant conditioning, (b) that the distinction of classical and instrumental conditioning has become established as a textbook-construction device, (c) that use of the classical-instrumental distinction by textbook authors has "hardened" after a period of "fluidity" in the 1970s, (d) that the currency of references in the basic classical (as well as instrumental) conditioning chapters diminished from 1952 to 1995. Findings are discussed in regard to the possibility that, as a class, and in comparison to other textbooks, the textbooks of the psychology of learning fall short of fulfilling some of their recognized roles.

  14. Conditions for equality between entanglement-assisted and unassisted classical capacities of a quantum channel

    CERN Document Server

    Shirokov, M E

    2011-01-01

    Both necessary and sufficient conditions of coincidence of the entanglement-assisted capacity with the Holevo capacity of a quantum channel are obtained. By using these conditions the equality between these capacities as well as the strict inequality between them are proved for several classes of quantum channel. In particular, it is shown that coincidence of the entanglement-assisted capacity with the Holevo capacity of a quantum channel implies that the $\\chi$-essential part of this channel is entanglement-breaking (the $\\chi$-essential part is defined as a restriction of a channel obtained by discarding all states useless for transmission of classical information). The above conditions and their corollaries are extended to quantum channels with linear constraints. By using these conditions it is shown that the question of coincidence of the entanglement-assisted capacity with the Holevo capacity of a constrained channel depends on the form of the constraint.

  15. Classical Conditioning Components of the Orienting Reflex to Words Using Innocuous and Noxious Unconditioned Stimuli Under Different Conditioned Stimulus-Unconditioned Stimulus Intervals

    Science.gov (United States)

    Maltzman, Irving; And Others

    1977-01-01

    Concerns the examination of conditioned stimulus--unconditioned stimulus (CS--UCS) intervals of different lengths. Demonstrates the feasibility of using a forewarned reaction time procedure with an innocuous imperative stimulus for the investigation of classical conditioning. (Editor/RK)

  16. Conditional symmetries in axisymmetric quantum cosmologies with scalar fields and the fate of the classical singularities

    Science.gov (United States)

    Zampeli, Adamantia; Pailas, Theodoros; Terzis, Petros A.; Christodoulakis, T.

    2016-05-01

    In this paper, the classical and quantum solutions of some axisymmetric cosmologies coupled to a massless scalar field are studied in the context of minisuperspace approximation. In these models, the singular nature of the Lagrangians entails a search for possible conditional symmetries. These have been proven to be the simultaneous conformal symmetries of the supermetric and the superpotential. The quantization is performed by adopting the Dirac proposal for constrained systems, i.e. promoting the first-class constraints to operators annihilating the wave function. To further enrich the approach, we follow [1] and impose the operators related to the classical conditional symmetries on the wave function. These additional equations select particular solutions of the Wheeler-DeWitt equation. In order to gain some physical insight from the quantization of these cosmological systems, we perform a semiclassical analysis following the Bohmian approach to quantum theory. The generic result is that, in all but one model, one can find appropriate ranges of the parameters, so that the emerging semiclassical geometries are non-singular. An attempt for physical interpretation involves the study of the effective energy-momentum tensor which corresponds to an imperfect fluid.

  17. Facilitated acquisition of standard but not long delay classical eyeblink conditioning in behaviorally inhibited adolescents.

    Science.gov (United States)

    Caulfield, M D; VanMeenen, K M; Servatius, R J

    2015-02-01

    Adolescence is a key age in the development of anxiety disorders. The present study assessed the relationship between behavioral inhibition, a risk factor for anxiety typified by avoidance, and acquisition of the classically conditioned eyeblink response. 168 healthy high school students (mean age 15.7 years, 54% female) were given a battery of self-report measures including the Adult Measure of Behavioural Inhibition (AMBI). The study compared acquisition of three experimental training conditions. Two groups were given paired CS-US training: standard delay of 500-ms or long delay of 1000-ms with CS overlapping and co-terminating with a 50-ms airpuff US. A third group received unpaired training of 1000-ms CS and 50-ms airpuff US. Inhibited individuals showed greater acquisition of the conditioned eyeblink response in the 500-ms CS condition, but not in the paired 1000-ms condition. No differences in spontaneous blinks or reactivity to the stimulus were evident in the 1000-ms unpaired CS condition. Results support a relationship between associative learning and anxiety vulnerability that may be mediated by cerebellar functioning in inhibited individuals.

  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. Immunomodulation by classical conditioning in NZB/W (F1) mice: Lifespan and diurnal variation

    Science.gov (United States)

    Miguel, Mario André Leocadio; Menna-Barreto, Luiz

    2016-01-01

    Systemic Lupus Eritematosus (SLE) is a systemic inflammatory disease often treated with the agent cyclophosphamide (CY), known by provoking important adverse reactions to the organism. Ader and Cohen have demonstrated an alternative way of administrating this agent based on pavlovian conditioning, in order to reduce the aggression caused by CY. Considering the influence of the temporal organization on learning and memory processes, the purpose of this study was to understand the temporal aspects involved in the conditioned immunomodulation. In a search for circadian modulation, we selected NZB/W (F1) female mice, a strain that spontaneously develop SLE. Divided into two major groups, the animals were submitted, in different phases of day, to a classical conditioning immunomodulation protocol, consisting in weekly parings of saccharin solution and CY injections. The success of the paradigm was evaluated by comparing lifespan among the groups. Simultaneously, it was monitored the water intake behavior, in order to correlate the stability of two rhythmic parameters, amplitude and spectral power density of the 24-h rhythm, with the progression of SLE. Our results indicate that mice could benefit from the conditioning task performed either in the light phase or in the dark phase of the LD cycle, as expressed by an increased lifespan. Concerning the rhythmic parameters, there was evidence of association between the rhythmic stability and the evolution of SLE, demonstrated by the maintenance of healthy levels of amplitude and spectral potency of the 24-h rhythm in animals exposed to the conditioning paradigm. PMID:27226820

  20. Experimental Evidence of Classical Conditioning and Microscopic Engrams in an Electroconductive Material

    Science.gov (United States)

    Karbowski, Lukasz M.; Persinger, Michael A.

    2016-01-01

    Synthetic experimental substrates are indispensable tools which can allow researchers to model biological processes non-invasively in three-dimensional space. In this study, we investigated the capacities of an electroconductive material whose properties converge upon those of the brain. An electrically conductive material composed of carbohydrates, proteins, fats, ions, water, and trace amounts of other organic compounds and minerals was classically conditioned as inferred by electrophysiological measurements. Spectral densities evoked during the display of a conditioned stimulus (CS) probe were strongly congruent with those displayed during the conditioned-unconditioned stimulus pairing (CS-UCS). The neutral stimulus consisted of the pulsed light from a LED. The unconditioned stimulus was an alternating current. Interstimulus intervals >130 ms did not result in conditioned responses. Microscopic analysis of the chemically-fixed substratum revealed 10–200 μm wide ‘vessel structures’ within samples exposed to a stimulus. Greater complexity (increased fractal dimensions) was clearly discernable by light microscopy for stained sections of fixed samples that had been conditioned compared to various controls. The denser pixels indicated greater concentration of stain and increased canalization. Implications for learning and memory formation are discussed. PMID:27764215

  1. APPLICATION OF PREMACK’S THEORY TO A CLASSICALLY CONDITIONED SUCROSE AVERSION INDUCED BY X-RAY EXPOSURE,

    Science.gov (United States)

    for the applicability to classical conditioning of Premack’s reinforcement theory in which the rate of reinforced responding is determined in part by the precontingency rate of the response. (Author)

  2. Extended necessary condition for local operations and classical communication: Tight bound for all measurements

    Science.gov (United States)

    Cohen, Scott M.

    2015-06-01

    We give a necessary condition that a separable measurement can be implemented by local quantum operations and classical communication (LOCC) in any finite number of rounds of communication, generalizing and strengthening a result obtained previously. That earlier result involved a bound that is tight when the number of measurement operators defining the measurement is relatively small. The present results generalize that bound to one that is tight for any finite number of measurement operators, and we also provide an extension which holds when that number is infinite. We apply these results to the famous example on a 3 ×3 system known as "domino states," which were the first demonstration of nonlocality without entanglement. Our extended necessary condition provides another way of showing that these states cannot be perfectly distinguished by (finite-round) LOCC. It directly shows that this conclusion also holds for their related rotated domino states. We also introduce a class of problems involving the unambiguous discrimination of quantum states, each of which is an example where the states can be optimally discriminated by a separable measurement, but according to our condition, cannot be optimally discriminated by LOCC. These examples nicely illustrate the usefulness of the present results, since our earlier necessary condition, which the present result generalizes, is not strong enough to reach a conclusion in any of these cases.

  3. Eyeblink Classical Conditioning and Post Traumatic Stress Disorder – A Model Systems Approach

    Directory of Open Access Journals (Sweden)

    Bernard G Schreurs

    2015-04-01

    Full Text Available Not everyone exposed to trauma suffers flashbacks, bad dreams, numbing, fear, anxiety, sleeplessness, hyper-vigilance, hyperarousal, or an inability to cope, but those who do may suffer from post traumatic stress disorder (PTSD. PTSD is a major physical and mental health problem for military personnel and civilians exposed to trauma. There is still debate about the incidence and prevalence of PTSD especially among the military, but for those who are diagnosed, behavioral therapy and drug treatment strategies have proven to be less than effective. A number of these treatment strategies are based on rodent fear conditioning research and are capable of treating only some of the symptoms because the extinction of fear does not deal with the various forms of hyper-vigilance and hyperarousal experienced by people with PTSD. To help address this problem, we have developed a preclinical eyeblink classical conditioning model of PTSD in which conditioning and hyperarousal can both be extinguished. We review this model and discuss findings showing that unpaired stimulus presentations can be effective in reducing levels of conditioning and hyperarousal even when unconditioned stimulus intensity is reduced to the point where it is barely capable of eliciting a response. These procedures have direct implications for the treatment of PTSD and could be implemented in a virtual reality environment.

  4. Eyeblink classical conditioning and post-traumatic stress disorder - a model systems approach.

    Science.gov (United States)

    Schreurs, Bernard G; Burhans, Lauren B

    2015-01-01

    Not everyone exposed to trauma suffers flashbacks, bad dreams, numbing, fear, anxiety, sleeplessness, hyper-vigilance, hyperarousal, or an inability to cope, but those who do may suffer from post-traumatic stress disorder (PTSD). PTSD is a major physical and mental health problem for military personnel and civilians exposed to trauma. There is still debate about the incidence and prevalence of PTSD especially among the military, but for those who are diagnosed, behavioral therapy and drug treatment strategies have proven to be less than effective. A number of these treatment strategies are based on rodent fear conditioning research and are capable of treating only some of the symptoms because the extinction of fear does not deal with the various forms of hyper-vigilance and hyperarousal experienced by people with PTSD. To help address this problem, we have developed a preclinical eyeblink classical conditioning model of PTSD in which conditioning and hyperarousal can both be extinguished. We review this model and discuss findings showing that unpaired stimulus presentations can be effective in reducing levels of conditioning and hyperarousal even when unconditioned stimulus intensity is reduced to the point where it is barely capable of eliciting a response. These procedures have direct implications for the treatment of PTSD and could be implemented in a virtual reality environment.

  5. The effects of ethanol on the developing cerebellum and eyeblink classical conditioning.

    Science.gov (United States)

    Green, John T

    2004-01-01

    In rats, developmental ethanol exposure has been used to model the central nervous system deficits associated with human fetal alcohol syndrome. Binge-like ethanol exposure of neonatal rats depletes cells in the cerebellum, including Purkinje cells, granule cells, and deep nuclear cells, and produces deficits in simple tests of motor coordination. However, the extent to which anatomical damage is related to behavioral deficits has been difficult to estimate. Eyeblink classical conditioning is known to engage a discrete brain stem-cerebellar circuit, making it an ideal test of cerebellar functional integrity after developmental ethanol exposure. Eyeblink conditioning is a simple form of motor learning in which a neutral stimulus (such as a tone) comes to elicit an eyeblink when repeatedly paired with a stimulus that evokes an eyeblink prior to training (such as mild periorbital stimulation). In eyeblink conditioning, one of the deep cerebellar nuclei, the interpositus nucleus, as well as specific Purkinje cell populations, are sites of convergence for tone conditioned stimulus and somatosensory unconditioned stimulus information, and, together with brain stem nuclei, provide the necessary and sufficient substrate for the learned response. A series of studies have shown that eyeblink conditioning is impaired in both weanling and adult rats given binge-like exposure to ethanol as neonates. In addition, interpositus nucleus neurons from ethanol-exposed rats showed impaired activation during eyeblink conditioning. These deficits are accompanied by a permanent reduction In the deep cerebellar nuclear cell population. Because particular cerebellar cell populations are utilized in well-defined ways during eyeblink conditioning, conclusions regarding the underlying neural substrates of behavioral change after developmental ethanol exposure are greatly strengthened.

  6. 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

  7. 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.

  8. Spectral boundary conditions and solitonic solutions in a classical Sellmeier dielectric

    CERN Document Server

    Belgiorno, F; Viganò, A

    2016-01-01

    Electromagnetic field interactions in a dielectric medium represent a longstanding field of investigation, both at the classical level and at the quantum one. We propose a 1+1 dimensional toy-model which consists of an half-line filling dielectric medium, with the aim to set up a simplified situation where technicalities related to gauge invariance and, as a consequence, physics of constrained systems are avoided, and still interesting features appear. In particular, we simulate the electromagnetic field and the polarization field by means of two coupled scalar fields $\\phi$,$\\psi$ respectively, in a Hopfield-like model. We find that, in order to obtain a physically meaningful behaviour for the model, one has to introduce spectral boundary conditions depending on the particle spectrum one is dealing with. This is the first interesting achievement of our analysis. The second relevant achievement is that, by introducing a nonlinear contribution in the polarization field $\\psi$, with the aim of mimicking a third...

  9. Bilateral plasticity of Vibrissae SII representation induced by classical conditioning in mice.

    Science.gov (United States)

    Debowska, Weronika; Liguz-Lecznar, Monika; Kossut, Malgorzata

    2011-04-01

    The somatosensory cortex in mice contains primary (SI) and secondary (SII) areas, differing in somatotopic precision, topographic organization, and function. The role of SII in somatosensory processing is still poorly understood. SII is activated bilaterally during attentional tasks and is considered to play a role in tactile memory and sensorimotor integration. We measured the plasticity of SII activation after associative learning based on classical conditioning, in which unilateral stimulation of one row of vibrissae was paired with a tail shock. The training consisted of three daily 10 min sessions, during which 40 pairings were delivered. Cortical activation driven by stimulation of vibrissae was mapped with 2-[(14)C]deoxyglucose (2DG) autoradiography 1 d after the end of conditioning. We reported previously that the conditioning procedure resulted in unilateral enlargement of 2DG-labeled cortical representation of the "trained" row of vibrissae in SI. Here, we measured the width and intensity of the labeled region in SII. We found that both measured parameters in SII increased bilaterally. The increase was observed in cortical layers II/III and IV. Apparently, plasticity in SII is not a simple reflection of changes in SI. It may be attributable to bilateral integrative role of SII, its lesser topographical specificity, and strong involvement in attentional processing.

  10. Project DyAdd: classical eyeblink conditioning in adults with dyslexia and ADHD.

    Science.gov (United States)

    Laasonen, Marja; Kauppinen, Jenni; Leppämäki, Sami; Tani, Pekka; Harno, Hanna; Hokkanen, Laura; Wikgren, Jan

    2012-11-01

    In this study of the project DyAdd (Adult Dyslexia and Attention Deficit Disorder in Finland), classical eyeblink conditioning (EBC) was investigated in both delay and trace paradigms in adults (18-55 years) with dyslexia (n = 37), attention deficit-hyperactivity disorder (ADHD; n = 21), their comorbid combination (n = 8), and healthy controls (n = 35). In addition, the profiles of three participants with a rare autosomal dominant cerebellar disease were assessed (episodic ataxia type 2, EA-2). We found that participants with dyslexia were overall slower learners than controls in eyeblink conditioning. Further, they were the only group that had a reduced number of CRs in mediotemporal-dependent trace paradigm compared to the more cerebellum-dependent delay paradigm. Second, ADHD was found to be related to larger CR amplitude. Third, those with a comorbid condition learned faster and manifested CRs that were not well timed. Fourth, the cerebellar patients showed nearly no conditioning at all. Correlations between EBC and various neuropsychological domains (phonological processing, reading, spelling, arithmetic, executive functions, attention, and fine motor control) over all participants resulted in significant relations only for the delay paradigm: Increased amount of reading errors related with later peak latency and increased amount of self-corrections in fine motor control related with larger response magnitude. Within those who conditioned, relations emerged only for the trace paradigm: better spelling was related to larger response magnitude. These results do not lend support to the cerebellar hypothesis of dyslexia. On the contrary, dyslexia in its pure form seems to be related to a relative dysfunction of a larger hippocampal-cerebellar network. Further, larger responses in the ADHD group are suggested to result from their lowered responding threshold.

  11. PKMzeta maintains spatial, instrumental, and classically conditioned long-term memories.

    Directory of Open Access Journals (Sweden)

    Peter Serrano

    2008-12-01

    Full Text Available How long-term memories are stored is a fundamental question in neuroscience. The first molecular mechanism for long-term memory storage in the brain was recently identified as the persistent action of protein kinase Mzeta (PKMzeta, an autonomously active atypical protein kinase C (PKC isoform critical for the maintenance of long-term potentiation (LTP. PKMzeta maintains aversively conditioned associations, but what general form of information the kinase encodes in the brain is unknown. We first confirmed the specificity of the action of zeta inhibitory peptide (ZIP by disrupting long-term memory for active place avoidance with chelerythrine, a second inhibitor of PKMzeta activity. We then examined, using ZIP, the effect of PKMzeta inhibition in dorsal hippocampus (DH and basolateral amygdala (BLA on retention of 1-d-old information acquired in the radial arm maze, water maze, inhibitory avoidance, and contextual and cued fear conditioning paradigms. In the DH, PKMzeta inhibition selectively disrupted retention of information for spatial reference, but not spatial working memory in the radial arm maze, and precise, but not coarse spatial information in the water maze. Thus retention of accurate spatial, but not procedural and contextual information required PKMzeta activity. Similarly, PKMzeta inhibition in the hippocampus did not affect contextual information after fear conditioning. In contrast, PKMzeta inhibition in the BLA impaired retention of classical conditioned stimulus-unconditioned stimulus (CS-US associations for both contextual and auditory fear, as well as instrumentally conditioned inhibitory avoidance. PKMzeta inhibition had no effect on postshock freezing, indicating fear expression mediated by the BLA remained intact. Thus, persistent PKMzeta activity is a general mechanism for both appetitively and aversively motivated retention of specific, accurate learned information, but is not required for processing contextual, imprecise

  12. Transfer of classical eyeblink conditioning with electrical stimulation of mPFC or tone as conditioned stimulus in guinea pigs.

    Science.gov (United States)

    Yao, Juan; Wu, Guang-Yan; Liu, Guo-Long; Liu, Shu-Lei; Yang, Yi; Wu, Bing; Li, Xuan; Feng, Hua; Sui, Jian-Feng

    2014-11-01

    Learning with a stimulus from one sensory modality can facilitate subsequent learning with a new stimulus from a different sensory modality. To date, the characteristics and mechanism of this phenomenon named transfer effect still remain ambiguous. Our previous work showed that electrical stimulation of medial prefrontal cortex (mPFC) as a conditioned stimulus (CS) could successfully establish classical eyeblink conditioning (EBC). The present study aimed to (1) observe whether transfer of EBC learning would occur when CSs shift between central (mPFC electrical stimulation as a CS, mPFC-CS) and peripheral (tone as a CS, tone CS); (2) compare the difference in transfer effect between the two paradigms, delay EBC (DEBC) and trace EBC (TEBC). A total of 8 groups of guinea pigs were tested in the study, including 4 experimental groups and 4 control groups. Firstly, the experimental groups accepted central (or peripheral) CS paired with corneal airpuff unconditioned stimulus (US); then, CS shifted to the peripheral (or central) and paired with US. The control groups accepted corresponding central (or peripheral) CS and pseudo-paired with US, and then shifted CS from central (or peripheral) to peripheral (or central) and paired with US. The results showed that the acquisition rates of EBC were higher in experimental groups than in control groups after CS switching from central to peripheral or vice versa, and the CR acquisition rate was remarkably higher in DEBC than in TEBC in both transfer ways. The results indicate that EBC transfer can occur between learning established with mPFC-CS and tone CS. Memory of CS-US association for delay paradigm was less disturbed by the sudden switch of CS than for trace paradigm. This study provides new insight into neural mechanisms underlying conditioned reflex as well as the role of mPFC.

  13. Autonomic control of heart rate and blood pressure in spontaneously hypertensive rats during aversive classical conditioning.

    Science.gov (United States)

    Hatton, D C; Buchholz, R A; Fitzgerald, R D

    1981-12-01

    An examination was made of the heart rate (HR) and blood pressure (BP) responses of 7-9-wk-old spontaneously hypertensive rats (SHR) and genetical control Wistar/Kyoto (WKY) rats during aversive classical conditioning. Subsequent to the development of conditioned responding (CRs), assessments were made of the effects of selective autonomic blockade by methyl atropine (10 mg/kg), phentolamine (2 mg/kg), and propranolol (2 mg/kg). The CR complex in the two strains consisted of pressor BP CRs in conjunction with vagally mediated decelerative HR CRs in the SHR strain and sympathetically mediated accelerative HR CRs in the WKY strain. The decelerative SHR HR CR did not appear to be secondary to baroreceptor reflex activity, although such activity did appear to be involved in the pressor BP and decelerative HR orienting response (OR) and unconditioned response (UR) complex of the SHRs on the initial application of the CS and the US, respectively. Augmented pressor BP ORs, CRs, and URs in the SHRs relative to the WKYs and differential drug effects on BP and HR baselines of the two strains suggested the presence of enhanced sympathetic activity in the SHRs that was not reflected in the SHR decelerative HR CR. Phentolamine unmasked evidence of reflex beta 2-vasodilation deficiency in the SHRs that could have contributed to the enhancement of their BP OR and CR.

  14. 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.

  15. Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study

    Science.gov (United States)

    van Maanen, Annette; Meijer, Anne Marie; Smits, Marcel G; Oort, Frans J

    2017-01-01

    Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

  16. Reinforcement in an in Vitro Analog of Appetitive Classical Conditioning of Feeding Behavior in "Aplysia": Blockade by a Dopamine Antagonist

    Science.gov (United States)

    Reyes, Fredy D.; Mozzachiodi, Riccardo; Baxter, Douglas A.; Byrne, John H.

    2005-01-01

    In a recently developed in vitro analog of appetitive classical conditioning of feeding in "Aplysia," the unconditioned stimulus (US) was electrical stimulation of the esophageal nerve (En). This nerve is rich in dopamine (DA)-containing processes, which suggests that DA mediates reinforcement during appetitive conditioning. To test this…

  17. Investigating the Role of Hippocampal BDNF in Anxiety Vulnerability Using Classical Eyeblink Conditioning.

    Science.gov (United States)

    Janke, Kellie L; Cominski, Tara P; Kuzhikandathil, Eldo V; Servatius, Richard J; Pang, Kevin C H

    2015-01-01

    Dysregulation of brain-derived neurotrophic factor (BDNF), behavioral inhibition temperament (BI), and small hippocampal volume have been linked to anxiety disorders. Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER) as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY) rat. The present study examined the role of hippocampal BDNF in the facilitated delay CCER of WKY rats. Consistent with earlier work, acquisition was facilitated in WKY rats compared to the Sprague Dawley (SD) rats. Facilitated acquisition was associated with increased BDNF, TrkB, and Arc mRNA in the dentate gyrus of SD rats, but learning-induced increases in BDNF and Arc mRNA were significantly smaller in WKY rats. To determine whether reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region 1 h prior to training. BDNF infusion did not alter the acquisition of SD rats, but significantly dampened the acquisition of CCER in the WKY rats, such that acquisition was similar to SD rats. Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI. Facilitated associative learning may represent a vulnerability factor in the development of anxiety disorders.

  18. Investigating the role of hippocampal BDNF in anxiety vulnerability using classical eyeblink conditioning

    Directory of Open Access Journals (Sweden)

    Kellie L Janke

    2015-07-01

    Full Text Available Dysregulation of brain-derived neurotrophic factor (BDNF, behavioral inhibition temperament (BI and small hippocampal volume have been linked to anxiety disorders. Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY rat. The present study examined the role of hippocampal BDNF in the facilitated delay CCER of WKY rats. Consistent with earlier work, acquisition was facilitated in WKY rats compared to the SD rats. Facilitated acquisition was associated with increased BDNF, TrkB, and Arc mRNA in the dentate gyrus of SD rats, but learning-induced increases in BDNF and Arc mRNA were significantly smaller in WKY rats. To determine if reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region one hour prior to training. BDNF infusion did not alter the acquisition of SD rats, but significantly dampened the acquisition of CCER in the WKY rats, such that acquisition was similar to SD rats. Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI. Facilitated associative learning may represent a vulnerability factor in the development of anxiety disorders.

  19. Emotional stress evoked by classical fear conditioning induces yawning behavior in rats.

    Science.gov (United States)

    Kubota, Natsuko; Amemiya, Seiichiro; Yanagita, Shinya; Nishijima, Takeshi; Kita, Ichiro

    2014-04-30

    Yawning is often observed not only in a state of boredom or drowsiness but also in stressful emotional situations, suggesting that yawning is an emotional behavior. However, the neural mechanisms for yawning during stressful emotional situations have not been fully determined, though previous studies have suggested that both parvocellular oxytocin (OT) and corticotropin-releasing factor (CRF) neurons in the hypothalamic paraventricular nucleus (PVN) are responsible for induction of yawning. Thus, using ethological observations and c-Fos immunohistochemistry, we examined whether emotional stress evoked by classical fear conditioning is involved in induction of yawning behavior in freely moving rats. Emotional stress induced yawning behavior that was accompanied by anxiety-related behavior, and caused neuronal activation of the central nucleus of the amygdala (CeA), as well as increases in activity of both OT and CRF neurons in the PVN. These results suggest that emotional stress may induce yawning behavior, in which the neuronal activation of the CeA may have a key role.

  20. 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.

  1. Effects of Storage Time and Condition on Mineral Contents of Grape Pekmez Produced by Vacuum and Classical Methods

    Directory of Open Access Journals (Sweden)

    B. Kayisoglu

    2006-01-01

    Full Text Available This study was conducted to investigate the effect of storage period and conditions on chemical properties of boiled grape juice (pekmez produced from the grape variety of Kınalı Yapıncak using classical and vacuum methods. Pekmez samples were stored in 250 cc volumed jars. Products obtained using two different production methods were stored for 10 months in room conditions and at +4 ºC temperature. Starting from the beginning of the storage, mineral analyses were repeated in every two months. Average copper, manganese, phosphorus, and sodium contents in pekmez samples produced by vacuum method were higher than by classical method at the end of storage period. But, calcium content in pekmez samples produced by classical method was higher than that of the other. Zinc, iron, and potassium contents in either vacuum method or classical method were not significantly different. In conclusion; in general, mineral contents were better in pekmez produced by vacuum method than classical method. Phosphor, sodium, potassium, calcium, copper, zinc and manganese contents were affected significantly by storage period, but iron was not. In addition, storage condition did not affect sodium, zinc and iron contents.

  2. Reinforcement in an in vitro analog of appetitive classical conditioning of feeding behavior in Aplysia: blockade by a dopamine antagonist.

    Science.gov (United States)

    Reyes, Fredy D; Mozzachiodi, Riccardo; Baxter, Douglas A; Byrne, John H

    2005-01-01

    In a recently developed in vitro analog of appetitive classical conditioning of feeding in Aplysia, the unconditioned stimulus (US) was electrical stimulation of the esophageal nerve (En). This nerve is rich in dopamine (DA)-containing processes, which suggests that DA mediates reinforcement during appetitive conditioning. To test this possibility, methylergonovine was used to antagonize DA receptors. Methylergonovine (1 nM) blocked the pairing-specific increase in fictive feeding that is usually induced by in vitro classical conditioning. The present results and previous observation that methylergonovine also blocks the effects of contingent reinforcement in an in vitro analog of appetitive operant conditioning suggest that DA mediates reinforcement for appetitive associative conditioning of feeding in Aplysia.

  3. Hippocampal Non-Theta-Contingent Eyeblink Classical Conditioning: A Model System for Neurobiological Dysfunction.

    Science.gov (United States)

    Cicchese, Joseph J; Berry, Stephen D

    2016-01-01

    Typical information processing is thought to depend on the integrity of neurobiological oscillations that may underlie coordination and timing of cells and assemblies within and between structures. The 3-7 Hz bandwidth of hippocampal theta rhythm is associated with cognitive processes essential to learning and depends on the integrity of cholinergic, GABAergic, and glutamatergic forebrain systems. Since several significant psychiatric disorders appear to result from dysfunction of medial temporal lobe (MTL) neurochemical systems, preclinical studies on animal models may be an important step in defining and treating such syndromes. Many studies have shown that the amount of hippocampal theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning and attainment of asymptotic performance. Our lab has developed a brain-computer interface that makes eyeblink training trials contingent upon the explicit presence or absence of hippocampal theta. The behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to fourfold increase in learning speed over non-theta states. The non-theta behavioral impairment is accompanied by disruption of the amplitude and synchrony of hippocampal local field potentials, multiple-unit excitation, and single-unit response patterns dependent on theta state. Our findings indicate a significant electrophysiological and behavioral impact of the pretrial state of the hippocampus that suggests an important role for this MTL system in associative learning and a significant deleterious impact in the absence of theta. Here, we focus on the impairments in the non-theta state, integrate them into current models of psychiatric disorders, and suggest how improvement in our understanding of neurobiological oscillations is critical for theories and treatment of psychiatric

  4. Effects of Paradigm and Inter-Stimulus Interval on Age Differences in Eyeblink Classical Conditioning in Rabbits

    Science.gov (United States)

    Woodruff-Pak, Diana S.; Seta, Susan E.; Roker, LaToya A.; Lehr, Melissa A.

    2007-01-01

    The aim of this study was to examine parameters affecting age differences in eyeblink classical conditioning in a large sample of young and middle-aged rabbits. A total of 122 rabbits of mean ages of 4 or 26 mo were tested at inter-stimulus intervals (ISIs) of 600 or 750 msec in the delay or trace paradigms. Paradigm affected both age groups…

  5. 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.

  6. Accumulation of anthropogenic radionuclides in crops in conditions of water stream and classical hydroponics

    Energy Technology Data Exchange (ETDEWEB)

    Mayrapetyan, Khachatur; Hovsepyan, Albert; Daryadar, Mahsa; Alexanyan, Julietta; Tovmasyan, Anahit; Ghalachyan, Laura; Tadevosyan, Anna; Mayrapetyan, Stepan [Institute of Hydroponics Problems, NAS, Noragyugh 108, 0082, Yerevan (Armenia)

    2014-07-01

    Natural and artificial radionuclides (RN) dangerous for health are emitted into ecosystems because of human anthropogenic activities in the field of nuclear energetics. Biologically artificial RN {sup 90}Sr(T{sub 1/2}=28,6 years) and {sup 137}Cs (T{sub 1/2}=30,1 years)are very dangerous. Therefore obtaining radio-ecologically safe raw material of high quality is a very urgent problem now. Taking into account the above mentioned, in order to obtain ecologically safe raw material we carried out comparative radiochemical investigations on essential oil and medicinal plants peppermint(Mentha piperita L.) and sweet basil (Ocimum basilicum L.) grown in new water-stream (continuous, gully, cylindrical) and classical hydroponics, with the aim of revealing accumulation peculiarities of {sup 90}Sr and {sup 137}Cs. The results of experiments have shown that in classical hydroponics peppermint and sweet basil exceeded the same indices of water-stream hydroponics with {sup 90}Sr and {sup 137}Cs content 1,1-1,2; 1,2-1,3 and 1,5-1,8; 1,4-1,8 times, respectively. Moreover, sweet basil exceeded peppermint in water-stream hydroponics {sup 90}Sr 1,3-1,6; {sup 137}Cs 1,2-1,4 times and in classical hydroponics {sup 90}Sr 1,6; {sup 137}Cs 1,2 times. The content of controlled artificial RN in raw material did not exceed the allowed concentration limit (ACL). New water-stream hydroponics system worked out in Institute of Hydroponics Problems is a radio-ecologically more profitable method for producing raw material than classical hydroponics. At the same time water-stream hydroponics system in comparison with classical hydroponics promoted productivity (dry raw material) increase of peppermint and sweet basil 1,1-1,4 times. (authors)

  7. Glutamate Receptor Antagonist Infusions into the Basolateral and Medial Amygdala Reveal Differential Contributions to Olfactory vs. Context Fear Conditioning and Expression

    Science.gov (United States)

    Walker, David L.; Paschall, Gayla Y.; Davis, Michael

    2005-01-01

    The basolateral amygdala's involvement in fear acquisition and expression to visual and auditory stimuli is well known. The involvement of the basolateral and other amygdala areas in fear acquisition and expression to stimuli of other modalities is less certain. We evaluated the contribution of the basolateral and medial amygdala to olfactory and…

  8. Learning in a simple biological system: a pilot study of classical conditioning of human macrophages in vitro

    Directory of Open Access Journals (Sweden)

    Nilsonne Gustav

    2011-11-01

    Full Text Available Abstract Recent advances in cell biology and gene regulation suggest mechanisms whereby associative learning could be performed by single cells. Therefore, we explored a model of classical conditioning in human macrophages in vitro. In macrophage cultures, bacterial lipopolysaccharide (LPS; unconditioned stimulus was paired once with streptomycin (conditioned stimulus. Secretion of interleukin-6 (IL-6 was used as response measure. At evocation, conditioning was not observed. Levels of IL-6 were higher only in those cultures that had been exposed to LPS in the learning phase (p's However, habituation was evident, with a 62% loss of the IL-6 response after three LPS presentations (p

  9. Extracellular citrulline levels in the nucleus accumbens during the acquisition and extinction of a classical conditioned reflex with pain reinforcement.

    Science.gov (United States)

    Savel'ev, S A; Saul'skaya, N B

    2007-03-01

    Studies on Sprague-Dawley rats using in vivo microdialysis and HPLC showed that the acquisition and performance of a classical conditioned reflex with pain reinforcement was accompanied by increases in the concentrations of citrulline (a side product of nitric oxide formation) and arginine (the substrate of NO synthase) in the intercellular space of the nucleus accumbens. During extinction of the reflex, there was a decrease in the elevation of extracellular citrulline in this brain structure, which correlated with the extent of extinction of the reflex. Recovery of the reflex led to increases in arginine and citrulline levels in the nucleus accumbens. These data suggest that there is an increase in nitric oxide production in the nucleus accumbens during the acquisition and performance of a classical conditioned reflex with pain reinforcement, which decreases as the reflex is extinguished and recovers with recovery of the reflex.

  10. 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.

  11. 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.

  12. 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...

  13. Classical and remote post-conditioning effects on ischemia/reperfusion-induced acute oxidant kidney injury.

    Science.gov (United States)

    Kadkhodaee, Mehri; Najafi, Atefeh; Seifi, Behjat

    2014-11-01

    The present study aimed to analyze and compare the effects of classical and remote ischemic postconditioning (POC) on rat renal ischemia/reperfusion (IR)-induced acute kidney injury. After right nephrectomy, male rats were randomly assigned into four groups (n = 8). In the IR group, 45 min of left renal artery occlusion was induced followed by 24 h of reperfusion. In the classical POC group, after induction of 45 min ischemia, 4 cycles of 10 s of intermittent ischemia and reperfusion were applied to the kidney before complete restoring of renal blood. In the remote POC group, 4 cycles of 5 min ischemia and reperfusion of left femoral artery were applied after 45 min renal ischemia and right at the time of renal reperfusion. There was a reduction in renal function (increase in blood urea and creatinine) in the IR group. Application of both forms of POC prevented the IR-induced reduction in renal function and histology. There were also significant improvements in kidney oxidative stress status in both POC groups demonstrated by a reduction in malondialdehyde (MDA) formation and preservation of antioxidant levels comparing to the IR group. We concluded that both methods of POC have protective effects on renal function and histology possibly by a reduction in IR-induced oxidative stress.

  14. Contrasts in Infant Classical Eyeblink Conditioning as a Function of Premature Birth

    Science.gov (United States)

    Herbert, Jane S.; Eckerman, Carol O.; Goldstein, Ricki F.; Stanton, Mark E.

    2004-01-01

    The impact of premature birth on associative learning was evaluated using simple delay eyeblink conditioning in which a tone conditional stimulus was paired with an air puff unconditional stimulus. Fourteen preterm (28-31 weeks gestation) and 11 full-term infants completed at least 3 conditioning sessions, 1 week apart, at 5 months of age…

  15. 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.

  16. Expression of the immediate-early gene-encoded protein Egr-1 (zif268) during in vitro classical conditioning.

    Science.gov (United States)

    Mokin, Maxim; Keifer, Joyce

    2005-01-01

    Expression of the immediate-early genes (IEGs) has been shown to be induced by activity-dependent synaptic plasticity or behavioral training and is thought to play an important role in long-term memory. In the present study, we examined the induction and expression of the IEG-encoded protein Egr-1 during an in vitro neural correlate of eyeblink classical conditioning. The results showed that Egr-1 protein expression as determined by immunocytochemistry and Western blot analysis rapidly increased during the early stages of conditioning and remained elevated during the later stages. Further, expression of Egr-1 protein required NMDA receptor activation as it was blocked by bath application of AP-5. These findings suggest that the IEG-encoded proteins such as Egr-1 are activated during relatively simple forms of learning in vertebrates. In this case, Egr-1 may have a functional role in the acquisition phase of conditioning as well as in maintaining expression of conditioned responses.

  17. Perceptual and neural olfactory similarity in honeybees.

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    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.

  18. Perceptual and Neural Olfactory Similarity in Honeybees

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    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.

  19. Inactivation of the central nucleus of the amygdala blocks classical conditioning but not conditioning-specific reflex modification of rabbit heart rate.

    Science.gov (United States)

    Burhans, Lauren B; Schreurs, Bernard G

    2013-02-01

    Heart rate (HR) conditioning in rabbits is a widely used model of classical conditioning of autonomic responding that is noted for being similar to the development of conditioned heart rate slowing (bradycardia) in humans. We have shown previously that in addition to HR changes to a tone conditioned stimulus (CS), the HR reflex itself can undergo associative change called conditioning-specific reflex modification (CRM) that manifests when tested in the absence of the CS. Because CRM resembles the conditioned bradycardic response to the CS, we sought to determine if HR conditioning and CRM share a common neural substrate. The central nucleus of the amygdala (CeA) is a critical part of the pathway through which conditioned bradycardia is established. To test whether the CeA is also involved in the acquisition and/or expression of CRM, we inactivated the CeA with muscimol during HR conditioning or CRM testing. CeA inactivation blocked HR conditioning without completely preventing CRM acquisition or expression. These results suggest that the CeA may therefore only play a modulatory role in CRM. Theories on the biological significance of conditioned bradycardia suggest that it may represent a state of hypervigilance that facilitates the detection of new and changing contingencies in the environment. We relate these ideas to our results and discuss how they may be relevant to the hypersensitivity observed in fear conditioning disorders like post-traumatic stress.

  20. Sensory prediction or motor control? Application of marr-albus type models of cerebellar function to classical conditioning.

    Science.gov (United States)

    Lepora, Nathan F; Porrill, John; Yeo, Christopher H; Dean, Paul

    2010-01-01

    Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  1. Purkinje cell activity during classical conditioning with different conditional stimuli explains central tenet of Rescorla–Wagner model [corrected].

    Science.gov (United States)

    Rasmussen, Anders; Zucca, Riccardo; Johansson, Fredrik; Jirenhed, Dan-Anders; Hesslow, Germund

    2015-11-10

    A central tenet of Rescorla and Wagner's model of associative learning is that the reinforcement value of a paired trial diminishes as the associative strength between the presented stimuli increases. Despite its fundamental importance to behavioral sciences, the neural mechanisms underlying the model have not been fully explored. Here, we present findings that, taken together, can explain why a stronger association leads to a reduced reinforcement value, within the context of eyeblink conditioning. Specifically, we show that learned pause responses in Purkinje cells, which trigger adaptively timed conditioned eyeblinks, suppress the unconditional stimulus (US) signal in a graded manner. Furthermore, by examining how Purkinje cells respond to two distinct conditional stimuli and to a compound stimulus, we provide evidence that could potentially help explain the somewhat counterintuitive overexpectation phenomenon, which was derived from the Rescorla-Wagner model.

  2. Semantic classical conditioning and brain-computer interface (BCI control: Encoding of affirmative and negative thinking

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    Carolin A. Ruf

    2013-03-01

    Full Text Available The aim of the study was to investigate conditioned electroencephalographic (EEG responses to factually correct and incorrect statements in order to enable binary communication by means of a brain-computer interface (BCI. In two experiments with healthy participants true and false statements (serving as conditioned stimuli, CSs were paired with two different tones which served as unconditioned stimuli (USs. The features of the USs were varied and tested for their effectiveness to elicit differentiable conditioned reactions (CRs. After acquisition of the CRs, these CRs to true and false statements were classified offline using a radial basis function kernel support vector machine. A mean single-trial classification accuracy of 50.5% was achieved for differentiating conditioned yes versus no thinking and mean accuracies of 65.4% for classification of yes and 68.8% for no thinking (both relative to baseline were found using the best US. Analysis of the area under the curve of the conditioned EEG responses revealed significant differences between conditioned yes and no answers. Even though improvements are necessary, these first results indicate that the semantic conditioning paradigm could be a useful basis for further research regarding BCI communication in patients with complete locked-in syndrome (CLIS.

  3. 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.

  4. 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.

  5. The Classical Conditioning of Attitudes: A Comparative Study of Ages 8 to 18

    Science.gov (United States)

    O'Donnell, John M.; Brown, Mari J. K.

    1973-01-01

    Results of this study indicated that attitude conditioning increased with age and that the increase appeared to be a function of contingency awareness and perhaps also a function of the older subjects' having greater facility in transferring symbolic meaning. (Author)

  6. Can human autonomic classical conditioning occur without contingency awareness? The critical importance of the trial sequence.

    Science.gov (United States)

    Singh, Kulwinder; Dawson, Michael E; Schell, Anne M; Courtney, Christopher G; Payne, Andrew F H

    2013-04-01

    Most evidence suggests that awareness of the CS-US contingency is necessary for human autonomic conditioning. However, Schultz and Helmstetter (2010) reported unaware skin conductance conditioning using difficult-to-discriminate visual CSs. We sought to replicate these findings with procedures nearly identical to Schultz and Helmstetter among 66 participants. Results replicated the findings of significantly greater autonomic responding to CS+ than CS-; however, participants also demonstrated greater expectancy of shock to CS+ than CS- despite being classified as unaware. The differential expectancy and conditioning occurred only on trials that followed a CS+/CS- alternating sequence. On non-alternating trials, there was significantly higher expectancy and skin conductance responding to CS- compared to CS+. These results indicate that what initially appeared to be unaware differential conditioning was likely due to differential expectancy arising from a predictable trial sequence. These results underscore the critical importance of controlling for trial sequence effects in the study of learning.

  7. Phosphorylation of mitogen-activated protein kinase by one-trial and multi-trial classical conditioning.

    Science.gov (United States)

    Crow, T; Xue-Bian, J J; Siddiqi, V; Kang, Y; Neary, J T

    1998-05-01

    The pathway supporting the conditioned stimulus (CS) is one site of plasticity that has been studied extensively in conditioned Hermissenda. Several signal transduction pathways have been implicated in classical conditioning of this preparation, although the major emphasis has been on protein kinase C. Here we provide evidence for the activation and phosphorylation of a mitogen-activated protein kinase (MAPK) pathway by one-trial and multi-trial conditioning. A one-trial in vitro conditioning procedure consisting of light (CS) paired with the application of 5-HT results in the increased incorporation of 32PO4 into proteins detected with two-dimensional gel electrophoresis. Two of the phosphoproteins have molecular weights of 44 and 42 kDa, consistent with extracellular signal-regulated protein kinases (ERK1 and ERK2). Phosphorylation of the 44 and 42 kDa proteins by one-trial conditioning was inhibited by pretreatment with PD098059, A MEK1 (ERK-Activating kinase) inhibitor. Assays of ERK activity with brain myelin basic protein as a substrate revealed greater ERK activity for the group that received one-trial conditioning compared with an unpaired control group. Western blot analysis of phosphorylated ERK using antibodies recognizing the dually phosphorylated forms of ERK1 and ERK2 showed an increase in phosphorylation after one-trial conditioning compared with unpaired controls. The increased phosphorylation of ERK after one-trial conditioning was blocked by pretreatment with PD098059. Hermissenda that received 10 or 15 conditioning trials showed significant behavioral suppression compared with pseudo-random controls. After conditioning and behavioral testing, the conditioned animals showed significantly greater phosphorylation of ERK compared with the pseudo-random controls. These results show that the ERK-MAPK signaling pathway is activated in Pavlovian conditioning of Hermissenda.

  8. Finite-temperature Casimir pistons for an electromagnetic field with mixed boundary conditions and its classical limit

    Energy Technology Data Exchange (ETDEWEB)

    Teo, L P [Faculty of Information Technology, Multimedia University, Jalan Multimedia, Cyberjaya, 63100, Selangor Darul Ehsan (Malaysia)], E-mail: lpteo@mmu.edu.my

    2009-03-13

    In this paper, the finite-temperature Casimir force acting on a two-dimensional Casimir piston due to an electromagnetic field is computed. It was found that if mixed boundary conditions are assumed on the piston and its opposite wall, then the Casimir force always tends to restore the piston toward the equilibrium position, regardless of the boundary conditions assumed on the walls transverse to the piston. In contrast, if pure boundary conditions are assumed on the piston and the opposite wall, then the Casimir force always tends to pull the piston toward the closer wall and away from the equilibrium position. The nature of the force is not affected by temperature. However, in the high-temperature regime, the magnitude of the Casimir force grows linearly with respect to temperature. This shows that the Casimir effect has a classical limit as has been observed in other literature.

  9. Food-aversive classical conditioning increases a persistent sodium current in molluscan withdrawal interneurons in a transcription dependent manner.

    Science.gov (United States)

    Kiss, Tibor; Pirger, Zsolt; Kemenes, György

    2009-07-01

    In this study we examined changes in a persistent sodium current (I(NaP)) after behavioral aversive classical conditioning in the snail Helix pomatia. We trained animals by pairing food with a mild electric shock that triggered the whole-body withdrawal reflex. This aversive training resulted in transcription dependent long-term associative memory. Isolated central nervous system preparations were set up from trained, random control and naive animals and using two-electrode voltage clamp methods, I(NaP) was activated and measured in identified body withdrawal interneurons RPa3 and LPa3. We show here that in preparations from conditioned animals I(NaP) is increased, suggesting that modifications in intrinsic cellular properties contribute to the formation of the memory trace. Blocking RNA synthesis by systemic injection of actinomycin D (0.12microM) suppressed both memory consolidation in intact animals and the learning-induced increase of I(NaP) in withdrawal interneurons, suggesting that aversive classical conditioning affects sodium channel expression at the transcriptional level.

  10. Dendritic excitability microzones and occluded long-term depression after classical conditioning of the rabbit's nictitating membrane response.

    Science.gov (United States)

    Schreurs, B G; Tomsic, D; Gusev, P A; Alkon, D L

    1997-01-01

    We made intradendritic recordings in Purkinje cells (n = 164) from parasaggital slices of cerebellar lobule HVI obtained from rabbits given paired presentations of tone and periorbital electrical stimulation (classical conditioning, n = 27) or explicitly unpaired presentations of tone and periorbital stimulation (control, n = 16). Purkinje cell dendritic membrane excitability, assessed by the current required to elicit local dendritic calcium spikes, increased significantly in slices from animals that received classical conditioning. In contrast, membrane potential, input resistance, and amplitude of somatic and dendritic spikes were not different in slices from animals given paired or explicitly unpaired stimulus presentations. The location of cells with low thresholds for local dendritic calcium spikes suggested that there are specific sites for learning-related changes within lobule HVI. These areas may correspond to learning "microzones" and are consistent with locations of learning-related in vivo changes in Purkinje cell activity. Application of 4-aminopyridine, an antagonist of the rapidly inactivating potassium current IA, reduced the threshold for dendritic spikes in slices from naive animals to levels found in slices from trained animals. In cells where thresholds for eliciting parallel fiber-stimulated Purkinje cell excitatory postsynaptic potentials (EPSPs) were measured, levels of parallel fiber stimulation required to elicit a 6-mV EPSP as well as a 4-mV EPSP (n = 30) and a Purkinje cell spike (n = 56) were found to be significantly lower in slices from paired animals than unpaired controls. A classical conditioning procedure was simulated in slices of lobule HVI by pairing a brief, high-frequency train of parallel fiber stimulation (8 pulses, 100 Hz) with a brief, lower frequency train of climbing fiber stimulation (3 pulses, 20 Hz) to the same Purkinje cell. Following paired stimulation of the parallel and climbing fibers, Purkinje cell EPSPs

  11. Balanced plasticity and stability of the electrical properties of a molluscan modulatory interneuron after classical conditioning: a computational study

    Directory of Open Access Journals (Sweden)

    Dimitris Vavoulis

    2010-05-01

    Full Text Available The Cerebral Giant Cells (CGCs are a pair of identified modulatory interneurons in the Central Nervous System of the pond snail Lymnaea stagnalis with an important role in the expression of both unconditioned and conditioned feeding behavior. Following single-trial food-reward classical conditioning, the membrane potential of the CGCs becomes persistently depolarized. This depolarization contributes to the conditioned response by facilitating sensory cell to command neuron synapses, which results in the activation of the feeding network by the conditioned stimulus. Despite the depolarization of the membrane potential, which enables the CGGs to play a key role in learning-induced network plasticity, there is no persistent change in the tonic firing rate or shape of the action potentials, allowing these neurons to retain their normal network function in feeding. In order to understand the ionic mechanisms of this novel combination of plasticity and stability of intrinsic electrical properties, we first constructed and validated a Hodgkin-Huxley-type model of the CGCs. We then used this model to elucidate how learning-induced changes in a somal persistent sodium and a delayed rectifier potassium current lead to a persistent depolarization of the CGCs whilst maintaining their firing rate. Including in the model an additional increase in the conductance of a high-voltage-activated calcium current allowed the spike amplitude and spike duration also to be maintained after conditioning. We conclude therefore that a balanced increase in three identified conductances is sufficient to explain the electrophysiological changes found in the CGCs after classical conditioning.

  12. Whisker-signaled Eyeblink Classical Conditioning in Head-fixed Mice.

    Science.gov (United States)

    Lin, Carmen; Disterhoft, John; Weiss, Craig

    2016-03-30

    Eyeblink conditioning is a common paradigm for investigating the neural mechanisms underlying learning and memory. To better utilize the extensive repertoire of scientific techniques available to study learning and memory at the cellular level, it is ideal to have a stable cranial platform. Because mice do not readily tolerate restraint, they are usually trained while moving about freely in a chamber. Conditioned stimulus (CS) and unconditioned stimulus (US) information are delivered and eyeblink responses recorded via a tether connected to the mouse's head. In the head-fixed apparatus presented here, mice are allowed to run as they desire while their heads are secured to facilitate experimentation. Reliable conditioning of the eyeblink response is obtained with this training apparatus, which allows for the delivery of whisker stimulation as the CS, a periorbital electrical shock as the US, and analysis of electromyographic (EMG) activity from the eyelid to detect blink responses.

  13. The Effects of Two Forms of Physical Activity on Eyeblink Classical Conditioning

    Science.gov (United States)

    Green, John T.; Chess, Amy C.; Burns, Montana; Schachinger, Kira M.; Thanellou, Alexandra

    2011-01-01

    Voluntary exercise, in the form of free access to a running wheel in the home cage, has been shown to improve several forms of learning and memory. Acrobatic training, in the form of learning to traverse an elevated obstacle course, has been shown to induce markers of neural plasticity in the cerebellar cortex in rodents. In three experiments, we examined the effects of these two forms of physical activity on delay eyeblink conditioning in rats. In Experiment 1, exercising rats were given 17 days of free access to a running wheel in their home cage prior to 10 days of delay eyeblink conditioning. Rats that exercised conditioned significantly better and showed a larger reflexive eyeblink unconditioned response to the periocular stimulation unconditioned stimulus than rats that did not exercise. In Experiment 2, exercising rats were given 17 days of free access to a running wheel in their home cage prior to 10 days of explicitly unpaired stimulus presentations. Rats that exercised responded the same to tone, light, and periocular stimulation as rats that did not exercise. In Experiment 3, acrobatic training rats were given 15 days of daily training on an elevated obstacle course prior to 10 days of eyeblink conditioning. Activity control rats underwent 15 days of yoked daily running in an open field. Rats that underwent acrobatic training did not differ in eyeblink conditioning from activity control rats. The ability to measure the learned response precisely, and the well-mapped neural circuitry of eyeblink conditioning offer some advantages for the study of exercise effects on learning and memory. PMID:21238502

  14. The effects of two forms of physical activity on eyeblink classical conditioning.

    Science.gov (United States)

    Green, John T; Chess, Amy C; Burns, Montana; Schachinger, Kira M; Thanellou, Alexandra

    2011-05-16

    Voluntary exercise, in the form of free access to a running wheel in the home cage, has been shown to improve several forms of learning and memory. Acrobatic training, in the form of learning to traverse an elevated obstacle course, has been shown to induce markers of neural plasticity in the cerebellar cortex in rodents. In three experiments, we examined the effects of these two forms of physical activity on delay eyeblink conditioning in rats. In Experiment 1, exercising rats were given 17 days of free access to a running wheel in their home cage prior to 10 days of delay eyeblink conditioning. Rats that exercised conditioned significantly better and showed a larger reflexive eyeblink unconditioned response to the periocular stimulation unconditioned stimulus than rats that did not exercise. In Experiment 2, exercising rats were given 17 days of free access to a running wheel in their home cage prior to 10 days of explicitly unpaired stimulus presentations. Rats that exercised responded the same to tone, light, and periocular stimulation as rats that did not exercise. In Experiment 3, acrobatic training rats were given 15 days of daily training on an elevated obstacle course prior to 10 days of eyeblink conditioning. Activity control rats underwent 15 days of yoked daily running in an open field. Rats that underwent acrobatic training did not differ in eyeblink conditioning from activity control rats. The ability to measure the learned response precisely, and the well-mapped neural circuitry of eyeblink conditioning offer some advantages for the study of exercise effects on learning and memory.

  15. Comparison of a classical with a highly formularized body condition scoring system for dairy cattle

    OpenAIRE

    Isense, A.; Leiber, F.; Bieber, A.; Spengler, A.; Ivemeyer, S.; Maurer, V.; Klocke, Peter

    2014-01-01

    Body condition scoring is a common tool to assess the subcutaneous fat reserves of dairy cows. Because of its subjectivity, which causes limits in repeatability, it is often discussed controversially. Aim of the current study was to evaluate the impact of considering the cows overall appearance on the scoring process and on the validity of the results. Therefore, two different methods to reveal body condition scores (BCS), ‘independent BCS’ (iBCS) and ‘dependent BCS’ (dBCS), were used to asse...

  16. Updated meta-analysis of classical fear conditioning in the anxiety disorders.

    Science.gov (United States)

    Duits, Puck; Cath, Danielle C; Lissek, Shmuel; Hox, Joop J; Hamm, Alfons O; Engelhard, Iris M; van den Hout, Marcel A; Baas, Joke M P

    2015-04-01

    The aim of the current study was twofold: (1) to systematically examine differences in fear conditioning between anxiety patients and healthy controls using meta-analytic methods, and (2) to examine the extent to which study characteristics may account for the variability in findings across studies. Forty-four studies (published between 1920 and 2013) with data on 963 anxiety disordered patients and 1,222 control subjects were obtained through PubMed and PsycINFO, as well as from a previous meta-analysis on fear conditioning (Lissek et al.). Results demonstrated robustly increased fear responses to conditioned safety cues (CS-) in anxiety patients compared to controls during acquisition. This effect may represent an impaired ability to inhibit fear in the presence of safety cues (CS-) and/or may signify an increased tendency in anxiety disordered patients to generalize fear responses to safe stimuli resembling the conditioned danger cue (CS+). In contrast, during extinction, patients show stronger fear responses to the CS+ and a trend toward increased discrimination learning (differentiation between the CS+ and CS-) compared to controls, indicating delayed and/or reduced extinction of fear in anxiety patients. Finally, none of the included study characteristics, such as the type of fear measure (subjective vs. psychophysiological index of fear), could account significantly for the variance in effect sizes across studies. Further research is needed to investigate the predictive value of fear extinction on treatment outcome, as extinction processes are thought to underlie the beneficial effects of exposure treatment in anxiety disorders.

  17. Role of nitric oxide in classical conditioning of siphon withdrawal in Aplysia.

    Science.gov (United States)

    Antonov, Igor; Ha, Thomas; Antonova, Irina; Moroz, Leonid L; Hawkins, Robert D

    2007-10-10

    Nitric oxide (NO) is thought to be involved in several forms of learning in vivo and synaptic plasticity in vitro, but very little is known about the role of NO during physiological forms of plasticity that occur during learning. We addressed that question in a simplified preparation of the Aplysia siphon-withdrawal reflex. We first used in situ hybridization to show that the identified L29 facilitator neurons express NO synthase. Furthermore, exogenous NO produced facilitation of sensory-motor neuron EPSPs, and an inhibitor of NO synthase or an NO scavenger blocked behavioral conditioning. Application of the scavenger to the ganglion or injection into a sensory neuron blocked facilitation of the EPSP and changes in the sensory-neuron membrane properties during conditioning. Injection of the scavenger into the motor neuron reduced facilitation without affecting sensory neuron membrane properties, and injection of an inhibitor of NO synthase had no effect. Postsynaptic injection of an inhibitor of exocytosis had effects similar to injection of the scavenger. However, changes in the shape of the EPSP during conditioning were not consistent with postsynaptic AMPA-like receptor insertion but were mimicked by presynaptic spike broadening. These results suggest that NO makes an important contribution during conditioning and acts directly in both the sensory and motor neurons to affect different processes of facilitation at the synapses between them. In addition, they suggest that NO does not come from either the sensory or motor neurons but rather comes from another source, perhaps the L29 interneurons.

  18. A NECESSARY AND SUFFICIENT CONDITION FOR GLOBAL EXISTENCE OF CLASSICAL SOLUTIONS TO CAUCHY PROBLEM OF QUASILINEAR HYPERBOLIC SYSTEMS IN DIAGONAL FORM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This article considers Cauchy problem for quasilinear hyperbolic systems in diagonal form.A necessary and sufficient condition in guaranteeing that Cauchy problem admits a unique global classical solution on t 0 is obtained,and a sharp estimate of the life span for the classical solution is given.

  19. Classical conditioning in borderline personality disorder: an fMRI study.

    Science.gov (United States)

    Krause-Utz, Annegret; Keibel-Mauchnik, Jana; Ebner-Priemer, Ulrich; Bohus, Martin; Schmahl, Christian

    2016-06-01

    Previous research suggests disturbed emotional learning and memory in borderline personality disorder (BPD). Studies investigating the neural correlates of aversive differential delay conditioning in BPD are currently lacking. We aimed to investigate acquisition, within-session extinction, between-session extinction recall, and reacquisition. We expected increased activation in the insula, amygdala, and anterior cingulate, and decreased prefrontal activation in BPD patients. During functional magnetic resonance imaging, 27 medication-free female BPD patients and 26 female healthy controls (HC) performed a differential delay aversive conditioning paradigm. An electric shock served as unconditioned stimulus, two neutral pictures as conditioned stimuli (CS+/CS-). Dependent variables were blood-oxygen-level-dependent response, skin conductance response (SCR), and subjective ratings (valence, arousal). No significant between-group differences in brain activation were found [all p(FDR) > 0.05]. Within-group comparisons for CS+unpaired > CS- revealed increased insula activity in BPD patients but not in HC during early acquisition; during late acquisition, both groups recruited fronto-parietal areas [p(FDR)  CS during extinction. During extinction recall, there was a trend for stronger SCR to CS+ > CS in BPD patients. Amygdala habituation to CS+paired (CS+ in temporal contingency with the aversive event) during acquisition was found in HC but not in patients. Our findings suggest altered temporal response patterns in terms of increased vigilance already during early acquisition and delayed extinction processes in individuals with BPD.

  20. Acetylcholine and Olfactory Perceptual Learning

    Science.gov (United States)

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

    2004-01-01

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

  1. 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.)

  2. Autism and classical eyeblink conditioning: Performance changes of the conditioned response related to autism spectrum disorder diagnosis

    Directory of Open Access Journals (Sweden)

    John P Welsh

    2016-08-01

    Full Text Available Changes in the timing performance of conditioned responses (CRs acquired during trace and delay eyeblink conditioning (EBC are presented for diagnostic subgroups of children having autism spectrum disorder (ASD aged 6-15 years. Children diagnosed with autistic disorder (AD were analyzed separately from children diagnosed with either Asperger’s syndrome or Pervasive-developmental disorder not-otherwise-specified (Asp/PDD and compared to an age- and IQ-matched group of children that were typically developing (TD. Within-subject and between-groups contrasts in CR performance on sequential exposure to trace and delay EBC were analyzed to determine whether any differences would expose underlying functional heterogeneities of the cerebral and cerebellar systems in ASD subgroups. The EBC parameters measured were percentage CRs, CR onset latency, and CR peak latency. Neither AD nor Asp/PDD groups were impaired in CR acquisition during trace or delay EBC. AD and Asp/PDD both altered CR timing, but not always in the same way. Although the AD group showed normal CR timing during trace EBC, the Asp/PDD group showed a significant 27 and 28 ms increase in CR onset and peak latency, respectively, during trace EBC. In contrast, the direction of the timing change was opposite during delay EBC, during which the Asp/PDD group showed a significant 29 ms decrease in CR onset latency and the AD group showed a larger 77 ms decrease in CR onset latency. Only the AD group showed a decrease in CR peak latency during delay EBC, demonstrating another difference between AD and Asp/PDD. The difference in CR onset latency during delay EBC for both AD and Asp/PDD was due to an abnormal prevalence of early onset CRs that were intermixed with CRs having normal timing, as observed both in CR onset histograms and mean CR waveforms. In conclusion, significant heterogeneity in EBC performance was apparent within diagnostic groups, and this may indicate that EBC performance can

  3. Role of the hippocampus in contextual memory after classical aversive conditioning in pigeons (C. livia

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    Reis F.

    1999-01-01

    Full Text Available We investigated the effects of hippocampal lesions with ibotenic acid (IBO on the memory of the sound-context-shock association during reexposure to the conditioning context. Twenty-nine adult pigeons were assigned to a non-lesioned control group (CG, N = 7, a sham-lesioned group (SG, N = 7, a hippocampus-lesioned experimental group (EG, N = 7, and to an unpaired nonlesioned group (tone-alone exposure (NG, N = 8. All pigeons were submitted to a 20-min session in the conditioning chamber with three associations of sound (1000 Hz, 85 dB, 1 s and shock (10 mA, 1 s. Experimental and sham lesions were performed 24 h later (EG and SG when EG birds received three bilateral injections (anteroposterior (A, 4.5, 5.25 and 7.0 of IBO (1 µl and 1 µg/µl and SG received one bilateral injection (A, 5.25 of PBS. The animals were reexposed to the training context 5 days after the lesion. Behavior was videotaped for 20 min and analyzed at 30-s intervals. A significantly higher percent rating of immobility was observed for CG (median, 95.1; range, 79.2 to 100.0 and SG (median, 90.0; range, 69.6 to 95.0 compared to EG (median, 11.62; range, 3.83 to 50.1 and NG (median, 7.33; range, 6.2 to 28.1 (P<0.001 in the training context. These results suggest impairment of contextual fear in birds who received lesions one day after conditioning and a role for the hippocampus in the modulation of emotional aversive memories in pigeons.

  4. Sensory prediction or motor control? Application of Marr-Albus type models of cerebellar function to classical conditioning

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    Nathan F Lepora

    2010-10-01

    Full Text Available Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  5. Expectancy-learning and evaluative learning in human classical conditioning: affective priming as an indirect and unobtrusive measure of conditioned stimulus valence.

    Science.gov (United States)

    Hermans, Dirk; Vansteenwegen, Debora; Crombez, Geert; Baeyens, Frank; Eelen, Paul

    2002-03-01

    It has been argued that in classical conditioning two processes might be operative. First, one may learn that the conditioned stimulus (CS+) is a valid predictor for the occurrence of the biologically negative or positive event (US; expectancy-learning). Second, one may learn to perceive the conditioned stimulus itself as a negative or positive stimulus, depending on the valence of the event it has been associated with (evaluative learning). Until the present, however, both forms of learning have been investigated using rather different conditioning procedures. Using a differential aversive conditioning preparation with pictures of human faces as CSs and an electrocutaneous stimulus as US, we were able to demonstrate that both forms of learning can co-occur. Moreover, the extent of evaluative learning in this aversive conditioning procedure did not significantly differ from the amount of evaluative learning in an evaluative conditioning procedure with positive and negative adjectives as USs, which was administered to the same participants. In the present study evaluative learning was not only indexed by direct evaluative ratings, but we introduced affective priming as an indirect and unobtrusive, reaction time based measure of stimulus valence. Finally, imagery instructions during acquisition did not facilitate expectancy-learning nor evaluative learning.

  6. Comparison of a classical with a highly formularized body condition scoring system for dairy cattle.

    Science.gov (United States)

    Isensee, A; Leiber, F; Bieber, A; Spengler, A; Ivemeyer, S; Maurer, V; Klocke, P

    2014-12-01

    Body condition scoring is a common tool to assess the subcutaneous fat reserves of dairy cows. Because of its subjectivity, which causes limits in repeatability, it is often discussed controversially. Aim of the current study was to evaluate the impact of considering the cows overall appearance on the scoring process and on the validity of the results. Therefore, two different methods to reveal body condition scores (BCS), 'independent BCS' (iBCS) and 'dependent BCS' (dBCS), were used to assess 1111 Swiss Brown Cattle. The iBCS and the dBCS systems were both working with the same flowchart with a decision tree structure for visual and palpatory assessment using a scale from 2 to 5 with increment units of 0.25. The iBCS was created strictly complying with the defined frames of the decision tree structure. The system was chosen due to its formularized approach to reduce the influence of subjective impressions. By contrast, the dBCS system, which was in line with common practice, had a more open approach, where - besides the decision tree - the overall impression of the cow's physical appearance was taken into account for generating the final score. Ultrasound measurement of the back fat thickness (BFT) was applied as a validation method. The dBCS turned out to be the better predictor of BFT, explaining 67.3% of the variance. The iBCS was only able to explain 47.3% of the BFT variance. Within the whole data set, only 31.3% of the animals received identical dBCS and iBCS. The pin bone region caused the most deviations between dBCS and iBCS, but also assessing the pelvis line, the hook bones and the ligaments led to divergences in around 20% of the scored animals. The study showed that during the assessment of body condition a strict adherence to a decision tree is a possible source of inexact classifications. Some body regions, especially the pin bones, proved to be particularly challenging for scoring due to difficulties in assessing them. All the more, the inclusion

  7. Cortical spreading depression and involvement of the motor cortex, auditory cortex, and cerebellum in eyeblink classical conditioning of the rabbit.

    Science.gov (United States)

    Case, Gilbert R; Lavond, David G; Thompson, Richard F

    2002-09-01

    The interrelationships of cerebellar and cerebral neural circuits in the eyeblink paradigm were explored with the controlled application of cortical spreading depression (CSD) and lidocaine in the New Zealand albino rabbit. The initial research focus was directed toward the involvement of the motor cortex in the conditioned eyeblink response. However, CSD timing and triangulation results indicate that other areas in the cerebral cortex, particularly the auditory cortex (acoustic conditioned stimulus), appear to be critical for the CSD effect on the eyeblink response. In summary: (1) CSD can be elicited, monitored, and timed and its side effects controlled in 97% of awake rabbits in the right and/or left cerebral hemisphere(s) during eyeblink conditioning. (2) The motor cortex appears to play little or no part in classical conditioning of the eyeblink in the rabbit in the delay paradigm. (3) Inactivating the auditory cortex with CSD or lidocaine temporarily impairs the conditioned response during the first 5 to 15 days of training, but has little effect past that point.

  8. Intra-cerebellar infusion of the protein kinase Mzeta (PKMζ) inhibitor ZIP disrupts eyeblink classical conditioning

    Science.gov (United States)

    Chihabi, Kutibh; Morielli, Anthony D.; Green, John T.

    2016-01-01

    PKM-ζ, a constitutively active N-terminal truncated form of PKC-ζ, has long been implicated in a cellular correlate of learning, long-term potentiation (LTP). Inhibition of PKM-ζ with Zeta-inhibitory peptide (ZIP) has been shown in many brain structures to disrupt maintenance of AMPA receptors, irreversibly disrupting numerous forms of learning and memory that have been maintained for weeks. Delay eyeblink conditioning (EBC) is an established model for the assessment of cerebellar learning; here, we show that PKC-ζ and PKM-ζ are highly expressed in the cerebellar cortex, with highest expression found in Purkinje cell (PC) nuclei. Despite being highly expressed in the cerebellar cortex, no studies have examined how regulation of cerebellar PKM-ζ may affect cerebellar-dependent learning and memory. Given its disruption of learning in other brain structures, we hypothesized that ZIP would also disrupt delay EBC. We have shown that infusion of ZIP into the lobulus simplex of the rat cerebellar cortex can indeed significantly disrupt delay EBC. PMID:26949968

  9. Using eyeblink classical conditioning as a test of the functional consequences of exposure of the developing cerebellum to alcohol.

    Science.gov (United States)

    Green, John T

    2003-01-01

    Exposure of the developing brain to alcohol produces profound Purkinje cell loss in the cerebellum, and deficits in tests of motor coordination. However, the precise relationship between these two sets of findings has been difficult to determine. Eyeblink classical conditioning is known to engage a discrete brainstem-cerebellar circuit, making it an ideal test of cerebellar functional integrity after developmental alcohol exposure. In eyeblink conditioning, one of the deep cerebellar nuclei, the interpositus nucleus, as well as specific Purkinje cell populations, are sites of convergence for CS and US information. A series of studies have shown that eyeblink conditioning is impaired in both weanling and adult rats given binge-like exposure to alcohol as neonates, and that these deficits can be traced, at least in part, to impaired activation of cerebellar interpositus nucleus neurons and to an overall reduction in the deep cerebellar nuclear cell population. Because particular cerebellar cell populations are utilized in well-defined ways during eyeblink conditioning, conclusions regarding specific changes in the mediation of behavior by these cell populations are greatly strengthened. Further studies will be directed towards the impact of early exposure to alcohol on the functionality of specific Purkinje cell populations, as well as towards brainstem areas that process the tone CS and the somatosensory US.

  10. Facing Challenges in Differential Classical Conditioning Research: Benefits of a Hybrid Design for Simultaneous Electrodermal and Electroencephalographic Recording.

    Science.gov (United States)

    Pastor, M Carmen; Rehbein, Maimu Alissa; Junghöfer, Markus; Poy, Rosario; López, Raul; Moltó, Javier

    2015-01-01

    Several challenges make it difficult to simultaneously investigate central and autonomous nervous system correlates of conditioned stimulus (CS) processing in classical conditioning paradigms. Such challenges include, for example, the discrepant requirements of electroencephalography (EEG) and electrodermal activity (EDA) recordings with regard to multiple repetitions of conditions and sufficient trial duration. Here, we propose a MultiCS conditioning set-up, in which we increased the number of CSs, decreased the number of learning trials, and used trials of short and long durations for meeting requirements of simultaneous EEG-EDA recording in a differential aversive conditioning task. Forty-eight participants underwent MultiCS conditioning, in which four neutral faces (CS+) were paired four times each with aversive electric stimulation (unconditioned stimulus) during acquisition, while four different neutral faces (CS-) remained unpaired. When comparing after relative to before learning measurements, EEG revealed an enhanced centro-posterior positivity to CS+ vs. CS- during 368-600 ms, and subjective ratings indicated CS+ to be less pleasant and more arousing than CS-. Furthermore, changes in CS valence and arousal were strong enough to bias subjective ratings when faces of CS+/CS- identity were displayed with different emotional expression (happy, angry) in a post-experimental behavioral task. In contrast to a persistent neural and evaluative CS+/CS- differentiation that sustained multiple unreinforced CS presentations, electrodermal differentiation was rapidly extinguished. Current results suggest that MultiCS conditioning provides a promising paradigm for investigating pre-post-learning changes under minimal influences of extinction and overlearning of simple stimulus features. Our data also revealed methodological pitfalls, such as the possibility of occurring artifacts when combining different acquisition systems for central and peripheral

  11. Understanding the breakdown of classic two-phase theory and spray atomization at engine-relevant conditions

    Science.gov (United States)

    Dahms, Rainer N.

    2016-04-01

    A generalized framework for multi-component liquid injections is presented to understand and predict the breakdown of classic two-phase theory and spray atomization at engine-relevant conditions. The analysis focuses on the thermodynamic structure and the immiscibility state of representative gas-liquid interfaces. The most modern form of Helmholtz energy mixture state equation is utilized which exhibits a unique and physically consistent behavior over the entire two-phase regime of fluid densities. It is combined with generalized models for non-linear gradient theory and for liquid injections to quantify multi-component two-phase interface structures in global thermal equilibrium. Then, the Helmholtz free energy is minimized which determines the interfacial species distribution as a consequence. This minimal free energy state is demonstrated to validate the underlying assumptions of classic two-phase theory and spray atomization. However, under certain engine-relevant conditions for which corroborating experimental data are presented, this requirement for interfacial thermal equilibrium becomes unsustainable. A rigorously derived probability density function quantifies the ability of the interface to develop internal spatial temperature gradients in the presence of significant temperature differences between injected liquid and ambient gas. Then, the interface can no longer be viewed as an isolated system at minimal free energy. Instead, the interfacial dynamics become intimately connected to those of the separated homogeneous phases. Hence, the interface transitions toward a state in local equilibrium whereupon it becomes a dense-fluid mixing layer. A new conceptual view of a transitional liquid injection process emerges from a transition time scale analysis. Close to the nozzle exit, the two-phase interface still remains largely intact and more classic two-phase processes prevail as a consequence. Further downstream, however, the transition to dense-fluid mixing

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

    Directory of Open Access Journals (Sweden)

    Gianluca Polese

    2016-05-01

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

  13. fMRI study of the role of glutamate NMDA receptor in the olfactory adaptation in rats: Insights into cellular and molecular mechanisms of olfactory adaptation.

    Science.gov (United States)

    Zhao, Fuqiang; Wang, Xiaohai; Zariwala, Hatim A; Uslaner, Jason M; Houghton, Andrea K; Evelhoch, Jeffrey L; Hostetler, Eric; Winkelmann, Christopher T; Hines, Catherine D G

    2017-02-03

    Olfactory adaptation, characterized by attenuation of response to repeated odor stimulations or continuous odor exposure, is an intrinsic feature of olfactory processing. Adaptation can be induced by either "synaptic depression" due to depletion of neurotransmitters, or "enhanced inhibition" onto principle neurons by local inhibitory interneurons in olfactory structures. It is not clear which mechanism plays a major role in olfactory adaptation. More importantly, molecular sources of enhanced inhibition have not been identified. In this study, olfactory responses to either repeated 40-s stimulations with interstimulus intervals (ISI) of 140-s or 30-min, or a single prolonged 200-s stimulus were measured by fMRI in different naïve rats. Olfactory adaptations in the olfactory bulb (OB), anterior olfactory nucleus (AON), and piriform cortex (PC) were observed only with repeated 40-s odor stimulations, and no olfactory adaptations were detected during the prolonged 200-s stimulation. Interestingly, in responses to repeated 40-s odor stimulations in the PC, the first odor stimulation induced positive activations, and odor stimulations under adapted condition induced negative activations. The negative activations suggest that "sparse coding" and "global inhibition" are the characteristics of olfactory processing in PC, and the global inhibition manifests only under an adapted condition, not a naïve condition. Further, we found that these adaptations were NMDA receptor dependent; an NMDA receptor antagonist (MK801) blocked the adaptations. Based on the mechanism that glutamate NMDA receptor plays a role in the inhibition onto principle neurons by interneurons, our data suggest that the olfactory adaptations are caused by enhanced inhibition from interneurons. Combined with the necessity of the interruption of odor stimulation to observe the adaptations, the molecular source for the enhanced inhibition is most likely an increased glutamate release from presynaptic

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Attention and Olfactory Consciousness

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    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.

  17. 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

  18. The effects of feeding unpredictability and classical conditioning on pre-release training of white-lipped peccary (Mammalia, Tayassuidae.

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    Selene S C Nogueira

    Full Text Available Some authors have suggested that environmental unpredictability, accompanied by some sort of signal for behavioral conditioning, can boost activity or foster exploratory behavior, which may increase post-release success in re-introduction programs. Thus, using white-lipped peccary (Tayassu pecari, a vulnerable Neotropical species, as a model, we evaluated an unpredictable feeding schedule. Associating this with the effect of classical conditioning on behavioral activities, we assessed the inclusion of this approach in pre-release training protocols. The experimental design comprised predictable feeding phases (control phases: C1, C2 and C3 and unpredictable feeding phases (U1- signaled and U2- non-signaled. The animals explored more during the signaled and non-signaled unpredictable phases and during the second control phase (C2 than during the other two predictable phases (C1 and C3. The peccaries also spent less time feeding during the signaled unpredictable phase (U1 and the following control phase (C2 than during the other phases. Moreover, they spent more time in aggressive encounters during U1 than the other experimental phases. However, the animals did not show differences in the time they spent on affiliative interactions or in the body weight change during the different phases. The signaled unpredictability, besides improving foraging behavior, showing a prolonged effect on the next control phase (C2, also increased the competition for food. The signaled feeding unpredictability schedule, mimicking wild conditions by eliciting the expression of naturalistic behaviors in pre-release training, may be essential to fully prepare them for survival in the wild.

  19. Involvement of the ipsilateral and contralateral cerebellum in the acquisition of unilateral classical eyeblink conditioning in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Bo HU; Xi LIN; Lushuai HUANG; Li YANG; Hua FENG; Jianfeng SUI

    2009-01-01

    Aim:The aim of this study was to evaluate the relative contributions of the ipsilateral and contralateral cerebellum to the acquisition of unilateral classical eyeblink conditioning (EBCC).Methods: The unilateral EBCC was achieved using a binaural tone conditioned stimulus (CS) paired with a left airpuff unconditioned stimulus (US).A high-resolution potentiometer was used to monitor eyeblink responses.Guinea pigs received one CS-US session followed by three CS-US sessions (sessions 2 to 4),during which microinjections of muscimol,a GABAA receptor agonist,were performed to reversibly inactivate the cerebellum unilaterally prior to training.To test whether any learning had occurred during these inactivation sessions,training was continued for six more CS-US sessions (sessions 5 to 10) without any inactivation.Results: Animals with inactivation of the left cerebellum had no signs of left conditioned response (CR) during sessions 2 to 4,and their CR acquisition during sessions 5 to 10 was not distinguishable from that of control animals during sessions 2 to 7.In contrast,animals with inactivation of the right cerebellum acquired left CRs during sessions 2 to 4,although their CR acquisition was significantly retarded during session 2.In addition,microinjections of muscimol into the right cerebellum did not affect left neuro-behavioral activity.Finally,microinjections of muscimol into either the left or the right cerebellum did not affect the performance of tone-airpuff evoked unconditioned response (UR).Conclusion: In contrast to the essential role of the ipsilateral cerebellum,the contralateral cerebellum is potentially involved in the acquisition of unilateral EBCC during the early stage of training.

  20. The Effects of Feeding Unpredictability and Classical Conditioning on Pre-Release Training of White-Lipped Peccary (Mammalia, Tayassuidae)

    Science.gov (United States)

    Nogueira, Selene S. C.; Abreu, Shauana A.; Peregrino, Helderes; Nogueira-Filho, Sérgio L. G.

    2014-01-01

    Some authors have suggested that environmental unpredictability, accompanied by some sort of signal for behavioral conditioning, can boost activity or foster exploratory behavior, which may increase post-release success in re-introduction programs. Thus, using white-lipped peccary (Tayassu pecari), a vulnerable Neotropical species, as a model, we evaluated an unpredictable feeding schedule. Associating this with the effect of classical conditioning on behavioral activities, we assessed the inclusion of this approach in pre-release training protocols. The experimental design comprised predictable feeding phases (control phases: C1, C2 and C3) and unpredictable feeding phases (U1- signaled and U2- non-signaled). The animals explored more during the signaled and non-signaled unpredictable phases and during the second control phase (C2) than during the other two predictable phases (C1 and C3). The peccaries also spent less time feeding during the signaled unpredictable phase (U1) and the following control phase (C2) than during the other phases. Moreover, they spent more time in aggressive encounters during U1 than the other experimental phases. However, the animals did not show differences in the time they spent on affiliative interactions or in the body weight change during the different phases. The signaled unpredictability, besides improving foraging behavior, showing a prolonged effect on the next control phase (C2), also increased the competition for food. The signaled feeding unpredictability schedule, mimicking wild conditions by eliciting the expression of naturalistic behaviors in pre-release training, may be essential to fully prepare them for survival in the wild. PMID:24475072

  1. 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.

  2. 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.

  3. Brain-derived neurotrophic factor (BDNF) expression in normal and regenerating olfactory epithelium of Xenopus laevis.

    Science.gov (United States)

    Frontera, Jimena Laura; Cervino, Ailen Soledad; Jungblut, Lucas David; Paz, Dante Agustín

    2015-03-01

    Olfactory epithelium has the capability to continuously regenerate olfactory receptor neurons throughout life. Adult neurogenesis results from proliferation and differentiation of neural stem cells, and consequently, olfactory neuroepithelium offers an excellent opportunity to study neural regeneration and the factors involved in the maintenance and regeneration of all their cell types. We analyzed the expression of BDNF in the olfactory system under normal physiological conditions as well as during a massive regeneration induced by chemical destruction of the olfactory epithelium in Xenopus laevis larvae. We described the expression and presence of BDNF in the olfactory epithelium and bulb. In normal physiological conditions, sustentacular (glial) cells and a few scattered basal (stem) cells express BDNF in the olfactory epithelium as well as the granular cells in the olfactory bulb. Moreover, during massive regeneration, we demonstrated a drastic increase in basal cells expressing BDNF as well as an increase in BDNF in the olfactory bulb and nerve. Together these results suggest an important role of BDNF in the maintenance and regeneration of the olfactory system.

  4. Toward a brain-computer interface for Alzheimer's disease patients by combining classical conditioning and brain state classification.

    Science.gov (United States)

    Liberati, Giulia; Dalboni da Rocha, Josué Luiz; van der Heiden, Linda; Raffone, Antonino; Birbaumer, Niels; Olivetti Belardinelli, Marta; Sitaram, Ranganatha

    2012-01-01

    Brain-computer interfaces (BCIs) provide alternative methods for communicating and acting on the world, since messages or commands are conveyed from the brain to an external device without using the normal output pathways of peripheral nerves and muscles. Alzheimer's disease (AD) patients in the most advanced stages, who have lost the ability to communicate verbally, could benefit from a BCI that may allow them to convey basic thoughts (e.g., "yes" and "no") and emotions. There is currently no report of such research, mostly because the cognitive deficits in AD patients pose serious limitations to the use of traditional BCIs, which are normally based on instrumental learning and require users to self-regulate their brain activation. Recent studies suggest that not only self-regulated brain signals, but also involuntary signals, for instance related to emotional states, may provide useful information about the user, opening up the path for so-called "affective BCIs". These interfaces do not necessarily require users to actively perform a cognitive task, and may therefore be used with patients who are cognitively challenged. In the present hypothesis paper, we propose a paradigm shift from instrumental learning to classical conditioning, with the aim of discriminating "yes" and "no" thoughts after associating them to positive and negative emotional stimuli respectively. This would represent a first step in the development of a BCI that could be used by AD patients, lending a new direction not only for communication, but also for rehabilitation and diagnosis.

  5. Ion association in concentrated NaCl brines from ambient to supercritical conditions: results from classical molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Collings Matthew D

    2002-11-01

    Full Text Available Highly concentrated NaCl brines are important geothermal fluids; chloride complexation of metals in such brines increases the solubility of minerals and plays a fundamental role in the genesis of hydrothermal ore deposits. There is experimental evidence that the molecular nature of the NaCl–water system changes over the pressure–temperature range of the Earth's crust. A transition of concentrated NaCl–H2O brines to a "hydrous molten salt" at high P and T has been argued to stabilize an aqueous fluid phase in the deep crust. In this work, we have done molecular dynamic simulations using classical potentials to determine the nature of concentrated (0.5–16 m NaCl–water mixtures under ambient (25°C, 1 bar, hydrothermal (325°C, 1 kbar and deep crustal (625°C, 15 kbar conditions. We used the well-established SPCE model for water together with the Smith and Dang Lennard-Jones potentials for the ions (J. Chem. Phys., 1994, 100, 3757. With increasing temperature at 1 kbar, the dielectric constant of water decreases to give extensive ion-association and the formation of polyatomic (NanClmn-m clusters in addition to simple NaCl ion pairs. Large polyatomic (NanClmn-m clusters resemble what would be expected in a hydrous NaCl melt in which water and NaCl were completely miscible. Although ion association decreases with pressure, temperatures of 625°C are not enough to overcome pressures of 15 kbar; consequently, there is still enhanced Na–Cl association in brines under deep crustal conditions.

  6. Intracellular correlates of acquisition and long-term memory of classical conditioning in Purkinje cell dendrites in slices of rabbit cerebellar lobule HVI.

    Science.gov (United States)

    Schreurs, B G; Gusev, P A; Tomsic, D; Alkon, D L; Shi, T

    1998-07-15

    Intradendritic recordings in Purkinje cells from a defined area in parasaggital slices of cerebellar lobule HVI, obtained after rabbits were given either paired (classical conditioning) or explicitly unpaired (control) presentations of tone and periorbital electrical stimulation, were used to assess the nature and duration of conditioning-specific changes in Purkinje cell dendritic membrane excitability. We found a strong relationship between the level of conditioning and Purkinje cell dendritic membrane excitability after initial acquisition of the conditioned response. Moreover, conditioning-specific increases in Purkinje cell excitability were still present 1 month after classical conditioning. Although dendritically recorded membrane potential, input resistance, and amplitude of somatic and dendritic spikes were not different in cells from paired or control animals, the size of a potassium channel-mediated transient hyperpolarization was significantly smaller in cells from animals that received classical conditioning. In slices of lobule HVI obtained from naive rabbits, the conditioning-related increases in membrane excitability could be mimicked by application of potassium channel antagonist tetraethylammonium chloride, iberiotoxin, or 4-aminopyridine. However, only 4-aminopyridine was able to reduce the transient hyperpolarization. The pharmacological data suggest a role for potassium channels and, possibly, channels mediating an IA-like current, in learning-specific changes in membrane excitability. The conditioning-specific increase in Purkinje cell dendritic excitability produces an afterhyperpolarization, which is hypothesized to release the cerebellar deep nuclei from inhibition, allowing conditioned responses to be elicited via the red nucleus and accessory abducens motorneurons.

  7. 非经典Ekman方程的解和演化条件%The Developing Conditions and Solutions of Non-classical Ekman's Equation

    Institute of Scientific and Technical Information of China (English)

    林振山

    2003-01-01

    An approximate equation of non-classical Ekman's flow and stochastic equations about Ekman's flow are set up in this paper.The developing conditions,solutions and the frequency response of the non-classical Ekman's flow are studied.The results show that the non-classicalEkman's flow will develop when the classical Ekman's flow shear is large enough and the non-classical Ekman's flow will tend to the most probable state (Us,Vs) or to (-fVe,fUe),respectively,in a similar condition or in a general condition.%建立了一个Ekman边界层的随机方程和非经典Ekman方程,研究了非经典Ekman流的频率响应、解和演化条件.有关研究结果表明,当经典Ekman流的切变足够大时,非经典Ekman流将发展起来,而且在相似条件和普适条件下,非经典Ekman流将分别朝最可几态(Us,Vs)或(-fVe,fU2)演化.

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

    Science.gov (United States)

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

    2011-10-19

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

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

    Directory of Open Access Journals (Sweden)

    L. Oboti

    2011-10-01

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

  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...... 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...

  11. Nonlinear dynamics of pattern formation and pattern recognition in the rabbit olfactory bulb

    Science.gov (United States)

    Baird, Bill

    1986-10-01

    A mathematical model of the process of pattern recognition in the first olfactory sensory cortex of the rabbit is presented. It explains the formation and alteration of spatial patterns in neural activity observed experimentally during classical Pavlovian conditioning. On each inspiration of the animal, a surge of receptor input enters the olfactory bulb. EEG activity recorded at the surface of the bulb undergoes a transition from a low amplitude background state of temporal disorder to coherent oscillation. There is a distinctive spatial pattern of rms amplitude in this oscillation which changes reliably to a second pattern during each successful recognition by the animal of a conditioned stimulus odor. When a new odor is paired as conditioned stimulus, these patterns are replaced by new patterns that stabilize as the animal adapts to the new environment. I will argue that a unification of the theories of pattern formation and associative memory is required to account for these observations. This is achieved in a model of the bulb as a discrete excitable medium with spatially inhomogeneous coupling expressed by a connection matrix. The theory of multiple Hopf bifurcations is employed to find coupled equations for the amplitudes of competing unstable oscillatory modes. These may be created in the system by proper coupling and selectively evoked by specific classes of inputs. This allows a view of limit cycle attractors as “stored” fixed points of a gradient vector field and thereby recovers the more familiar dynamical systems picture of associative memory.

  12. Olfactory Dysfunction in Older Adults is Associated with Feelings of Depression and Loneliness.

    Science.gov (United States)

    Sivam, Anita; Wroblewski, Kristen E; Alkorta-Aranburu, Gorka; Barnes, Lisa L; Wilson, Robert S; Bennett, David A; Pinto, Jayant M

    2016-05-01

    Olfactory dysfunction is a common complaint among physician visits. Olfactory loss affects quality of life and impairs function and activities of daily living. The purpose of our study was to assess the degree of odor identification associated with mental health. Olfactory function was measured using the brief smell identification test. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression scale. Loneliness was assessed by the de Jong-Gierveld Loneliness Scale. Cognition was measured by a battery of 19 cognitive tests. The frequency of olfactory dysfunction in our study was ~40%. Older subjects had worse olfactory performance, as previously found. More loneliness was associated with worse odor identification. Similarly, symptoms of depression were associated with worse olfaction (among men). Although better global cognitive function was strongly associated with better odor identification, after controlling for multiple factors, the associations with depression and loneliness were unchanged. Clinicians should assess these mental health conditions when treating older patients who present with olfactory deficits.

  13. 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.

  14. 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.

  15. Olfactory short-term memory encoding and maintenance - an event-related potential study.

    Science.gov (United States)

    Lenk, Steffen; Bluschke, Annet; Beste, Christian; Iannilli, Emilia; Rößner, Veit; Hummel, Thomas; Bender, Stephan

    2014-09-01

    This study examined whether the memory encoding and short term maintenance of olfactory stimuli is associated with neurophysiological activation patterns which parallel those described for sensory modalities such as vision and auditory. We examined olfactory event-related potentials in an olfactory change detection task in twenty-four healthy adults and compared the measured activation to that found during passive olfactory stimulation. During the early olfactory post-processing phase, we found a sustained negativity over bilateral frontotemporal areas in the passive perception condition which was enhanced in the active memory task. There was no significant lateralization in either experimental condition. During the maintenance interval at the end of the delay period, we still found sustained activation over bilateral frontotemporal areas which was more negative in trials with correct - as compared to incorrect - behavioural responses. This was complemented by a general significantly stronger frontocentral activation. Summarizing, we were able to show that olfactory short term memory involves a parallel sequence of activation as found in other sensory modalities. In addition to olfactory-specific frontotemporal activations in the memory encoding phase, we found slow cortical potentials over frontocentral areas during the memory maintenance phase indicating the activation of a supramodal memory maintenance system. These findings could represent the neurophysiological underpinning of the 'olfactory flacon', the olfactory counter-part to the visual sketchpad and phonological loop embedded in Baddeley's working memory model.

  16. Scattering of H(D) from LiF(1 0 0) under fast grazing incidence conditions: To what extent is classical dynamics a useful tool?

    Energy Technology Data Exchange (ETDEWEB)

    Muzas, A.S. [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Martín, F. [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-nanociencia), Cantoblanco, 28049 Madrid (Spain); Díaz, C., E-mail: cristina.diaz@uam.es [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-07-01

    Diffraction experiments of atoms and molecules under fast grazing incidence conditions have opened a new field in surface science. This experimental effort calls for complementary theoretical studies, which would allow a detailed analysis of experimental data. Here, we have analyzed the ability of classical dynamics simulations to reproduce experimental results. To perform this study, a DFT (density functional theory) based potential energy surface, describing the interaction between a H atom and a LiF(1 0 0) surface, has been computed. Diffraction probabilities have been simulated by means of a classical binning method. Our results have been found to be in qualitative good agreement with recent experimental measurements.

  17. Properties and mechanisms of olfactory learning and memory.

    Science.gov (United States)

    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.

  18. Properties and mechanisms of olfactory learning and memory

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. Failure of classical traffic and transportation theory: The maximization of the network throughput maintaining free flow conditions in network

    CERN Document Server

    Kerner, Boris S

    2016-01-01

    We show that the minimization of travel times in a network as generally accepted in classical traffic and transportation theories deteriorates the traffic system through a considerable increase in the probability of traffic breakdown in the network. We introduce a network characteristic {\\it minimum network capacity} that shows that rather than the minimization of travel times in the network, the minimization of the probability of traffic breakdown in the network maximizes the network throughput at which free flow persists in the whole network.

  1. 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.

  2. Coordinate action of pre- and postsynaptic brain-derived neurotrophic factor is required for AMPAR trafficking and acquisition of in vitro classical conditioning.

    Science.gov (United States)

    Li, W; Keifer, J

    2008-08-26

    Brain-derived neurotrophic factor (BDNF) has been implicated in mechanisms of synaptic plasticity such as long-term potentiation (LTP), but its role in associative learning remains largely unknown. In the present study, we investigated the function of BDNF and its receptor tropomyosin-related kinase B (TrkB) in an in vitro model of classical conditioning using pond turtles, Pseudemys scripta elegans. Conditioning resulted in a significant increase in BDNF and phospho (p)-Trk expression. Bath application of antibodies directed against TrkB, but not TrkA or TrkC, abolished acquisition of conditioning, as did a receptor tyrosine kinase inhibitor K252a and an inhibitor of nitric oxide synthase 7-nitroindazole. Significantly, injections of BDNF Ab into the nerve roots of presynaptic axonal projections or postsynaptic motor neurons prevented acquisition of conditioning, suggesting that BDNF is required on both sides of the synapse for modification to occur. The presynaptic proteins synaptophysin and synapsin I were increased upon conditioning or BDNF application. Furthermore, BDNF application alone mimicked conditioning-induced synaptic insertion of GluR1 and GluR4 AMPAR subunits into synapses, which was inhibited by co-application of BDNF and K252a. Data also show that extracellular signal-regulated kinase (ERK) was activated in BDNF-treated preparations. We conclude that coordinate pre- and postsynaptic actions of BDNF are required for acquisition of in vitro classical conditioning.

  3. 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.

  4. 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.

  5. Signal processing inspired from the olfactory bulb for electronic noses

    Science.gov (United States)

    Jing, Ya-Qi; Meng, Qing-Hao; Qi, Pei-Feng; Zeng, Ming; Liu, Ying-Jie

    2017-01-01

    A bio-inspired signal processing method is proposed for electronic noses (e-noses). The proposed method contains an olfactory bulb model and a feature generation step. The structure of the olfactory bulb model is similar to the anatomical structure of mammals’ olfactory bulb. It consists of olfactory receptor neurons, mitral cells, granule cells, periglomerular cells, and short axon cells. This model uses gas sensors’ original response curves and transforms them to neuron spiking series no matter what kind the response curve is. This largely simplifies the follow-up feature generation step. Recurrence quantification analysis is employed to perform feature generation and the five most important features are selected. Finally, in order to verify the performance of the proposed method, seven kinds of Chinese liquors are tested and three classification methods are used to classify them. The experimental results demonstrate that the proposed method has a higher classification rate (99.05%) and also a steadier performance with the change of sensor number and types than the classic one.

  6. N-methyl-D-aspartate receptor antagonist MK-801 impairs learning but not memory fixation or expression of classical fear conditioning in goldfish (Carassius auratus).

    Science.gov (United States)

    Xu, X; Davis, R E

    1992-04-01

    The amnestic effects of the noncompetitive antagonist MK-801 on visually mediated, classic fear conditioning in goldfish (Carassius auratus) was examined in 5 experiments. MK-801 was administered 30 min before the training session on Day 1 to look for anterograde amnestic effects, immediately after training to look for retrograde amnestic effects, and before the training or test session, or both, to look for state-dependence effects. The results showed that MK-801 produced anterograde amnesia at doses that did not produce retrograde amnesia or state dependency and did not impair the expression of conditioned or unconditioned branchial suppression responses (BSRs) to the conditioned stimulus. The results indicate that MK-801 disrupts the mechanism of learning of the conditioned stimulus-unconditioned stimulus relation. Evidence is also presented that the learning processes that are disrupted by MK-801 occur during the initial stage of BSR conditioning.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Classical antiparticles

    Energy Technology Data Exchange (ETDEWEB)

    Costella, J.P.; McKellar, B.H.J.; Rawlinson, A.A.

    1997-03-01

    We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain. (authors). 13 refs., 1 tab.

  9. Classical antiparticles

    CERN Document Server

    Costella, J P; Rawlinson, A A; Costella, John P.; Kellar, Bruce H. J. Mc; Rawlinson, Andrew A.

    1997-01-01

    We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain.

  10. 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.

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

    Science.gov (United States)

    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

  12. Environmental temperature modulates olfactory reception in Drosophila melanogaster.

    Science.gov (United States)

    Martin, Fernando; Riveron, Jacob; Alcorta, Esther

    2011-12-01

    Sensory systems, including the olfactory system, are able to adapt to changing environmental conditions. In nature, changes in temperature modify the volatility and concentration of odorants in the air. If the olfactory system does not adapt to these changes, it could relay wrong information about the distance to or direction of odor sources. Recent behavioral studies in Drosophila melanogaster showed olfactory acclimation to temperature. In this report, we investigated if temperature affects olfaction at the level of the receptors themselves. With this aim, we performed electroantennograms (EAGs) and single sensillum recordings (SSRs) to measure the response to several odorants in flies that had been submitted to temperature treatments. In response to all tested odorants, the amplitude of the EAGs increased in flies that had been exposed to a higher temperature and decreased after cold treatment, revealing that at least part of the reported change in olfactory perception happens at reception level. SSRs of odorant stimulated basiconic sensilla ab2 and ab3 showed some changes in the number of spikes after heat or cold treatment. However, the number and shape of spontaneous action potentials were unaffected, suggesting that the observed changes related specifically to the olfactory function of the neurons.

  13. Sad man's nose: Emotion induction and olfactory perception.

    Science.gov (United States)

    Flohr, Elena L R; Erwin, Elena; Croy, Ilona; Hummel, Thomas

    2017-03-01

    Emotional and olfactory processing is frequently shown to be closely linked both anatomically and functionally. Depression, a disease closely related to the emotional state of sadness, has been shown to be associated with a decrease in olfactory sensitivity. The present study focuses on the state of sadness in n = 31 healthy subjects in order to investigate the specific contribution of this affective state in the modulation of olfactory processing. A sad or indifferent affective state was induced using 2 movies that were presented on 2 separate days. Afterward, chemosensory-evoked potentials were recorded after stimulation with an unpleasant (hydrogen sulfide: "rotten eggs") or a pleasant (phenyl ethyl alcohol: "rose") odorant. Latencies of N1 and P2 peaks were longer after induction of the sad affective state. Additionally, amplitudes were lower in a sad affective state when being stimulated with the unpleasant odorant. Processing of olfactory input has thus been reduced under conditions of the sad affective state. We argue that the affective state per se could at least partially account for the reduced olfactory sensitivity in depressed patients. To our knowledge, the present study is the first to show influence of affective state on chemosensory event-related potentials. (PsycINFO Database Record

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Which solvent for olfactory testing?

    Science.gov (United States)

    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.

  16. Cleavage of proBDNF to BDNF by a tolloid-like metalloproteinase is required for acquisition of in vitro eyeblink classical conditioning.

    Science.gov (United States)

    Keifer, Joyce; Sabirzhanov, Boris E; Zheng, Zhaoqing; Li, Wei; Clark, Timothy G

    2009-11-25

    The tolloid/bone morphogenetic protein-1 family of metalloproteinases have an important role in the regulation of embryonic pattern formation and tissue morphogenesis. Studies suggest that they participate in mechanisms of synaptic plasticity in adults, but very little is known about their function. Recently, we isolated a reptilian ortholog of the tolloid gene family designated turtle tolloid-like gene (tTll). Here, we examined the role of tTLL in an in vitro model of eyeblink classical conditioning using an isolated brainstem preparation to assess its role in synaptic plasticity during conditioning. Analysis by real-time reverse transcription-PCR shows that an extracellularly secreted form of tTLL, tTLLs, is transiently expressed in the early stages of conditioning during conditioned response acquisition, whereas a cytosolic form, tTLLc, is not. Short interfering RNA (siRNA)-directed gene knockdown and rescue of tTLL expression demonstrate that it is required for conditioning. Significantly, we show that tTLLs cleaves the precursor proBDNF into mature BDNF in cleavage assay studies, and application of recombinant tTLLs protein alone to preparations results in induction of mature BDNF expression. The mature form of BDNF is minimally expressed in preparations treated with anti-tTLL siRNA, and the synaptic incorporation of both GluR1- and GluR4-containing AMPA receptors is significantly reduced, resulting in suppression of conditioning. This is the first study to demonstrate that expression of an extracellularly secreted tolloid-like metalloproteinase is regulated in the early stages of classical conditioning and functions in the conversion of proBDNF to mature BDNF. The mature form of BDNF is required for synaptic delivery of AMPA receptors and acquisition of conditioned responses.

  17. 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.  

  18. Exposure to Zinc Sulfate Results in Differential Effects on Olfactory Sensory Neuron Subtypes in Adult Zebrafish

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    James T. Hentig

    2016-08-01

    Full Text Available Zinc sulfate is a known olfactory toxicant, although its specific effects on the olfactory epithelium of zebrafish are unknown. Olfactory organs of adult zebrafish were exposed to zinc sulfate and, after 2, 3, 5, 7, 10 or 14 days, fish were processed for histological, immunohistochemical, ultrastructural, and behavioral analyses. Severe morphological disruption of the olfactory organ was observed two days following zinc sulfate exposure, including fusion of lamellae, epithelial inflammation, and significant loss of anti-calretinin labeling. Scanning electron microscopy revealed the apical surface of the sensory region was absent of ciliated structures, but microvilli were still present. Behavioral analysis showed significant loss of the ability to perceive bile salts and some fish also had no response to amino acids. Over the next several days, olfactory organ morphology, epithelial structure, and anti-calretinin labeling returned to control-like conditions, although the ability to perceive bile salts remained lost until day 14. Thus, exposure to zinc sulfate results in rapid degeneration of the olfactory organ, followed by restoration of morphology and function within two weeks. Zinc sulfate appears to have a greater effect on ciliated olfactory sensory neurons than on microvillous olfactory sensory neurons, suggesting differential effects on sensory neuron subtypes.

  19. Dietary Cholesterol Concentration and Duration Degrade Long-Term Memory of Classical Conditioning of the Rabbit’s Nictitating Membrane Response

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    Bernard G. Schreurs

    2012-01-01

    Full Text Available A rabbit model of Alzheimer’s disease based on feeding a cholesterol diet for eight weeks shows sixteen hallmarks of the disease, including learning and memory changes. Although we have shown 2% cholesterol and copper in water can retard learning, other studies show feeding dietary cholesterol before learning can improve acquisition whereas feeding cholesterol after learning can degrade long-term memory. We explored this issue by manipulating cholesterol concentration and duration following classical trace conditioning of the rabbit’s nictitating membrane response and assessed conditioned responding after eight weeks on cholesterol. First, rabbits given trace classical conditioning followed by 0.5%, 1%, or 2% cholesterol for eight weeks showed body weight and serum cholesterol levels that were a function of dietary cholesterol. Although all concentrations of cholesterol showed some sign of retarding long-term memory, the level of memory retardation was correlated with serum cholesterol levels. Second, rabbits given trace conditioning followed by different durations of a 2% cholesterol diet combined with different durations of a 0% control diet for 8 weeks showed duration and timing of a 2% cholesterol diet were important in affecting recall. The data support the idea that dietary cholesterol may retard long-term memory.

  20. Olfactory dysfunction in Down's Syndrome.

    Science.gov (United States)

    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.

  1. 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.

  2. 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.

  3. Classical eyeblink conditioning using electrical stimulation of caudal mPFC as conditioned stimulus is dependent on cerebellar interpositus nucleus in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Guang-yan WU; Juan YAO; Zheng-li FAN; Lang-qian ZHANG; Xuan LI; Chuang-dong ZHAO; Zhen-hua ZHOU; Jian-feng SUI

    2012-01-01

    Aim:To determine whether electrical stimulation of caudal medial prefrontal cortex (mPFC) as conditioned stimulus (CS) paired with airpuff unconditioned stimulus (US) was sufficient for establishing eyeblink conditioning in guinea pigs,and whether it was dependent on cerebellar interpositus nucleus.Methods:Thirty adult guinea pigs were divided into 3 conditioned groups,and trained on the delay eyeblink conditioning,short-trace eyeblink conditioning,and long-trace eyeblink conditioning paradigms,respectively,in which electrical stimulation of the right caudal mPFC was used as CS and paired with corneal airpuff US.A pseudo conditioned group of another 10 adult guinea pigs was given unpaired caudal mPFC electrical stimulation and the US.Muscimol (1 μg in 1 μL saline) and saline (1 μL) were infused into the cerebellar interpositus nucleus of the animals through the infusion cannula on d 11 and 12,respectively.Results:The 3 eyeblink conditioning paradigms have been successfully established in guinea pigs.The animals acquired the delay and short-trace conditioned responses more rapidly than long-trace conditioned responses.Muscimol infusion into the cerebellar interpositus nucleus markedly impaired the expression of the 3 eyeblink conditioned responses.Conclusion:Electrical stimulation of caudal mPFC is effective CS for establishing eyeblink conditioning in guinea pigs,and it is dependent on the cerebellar interpositus nucleus.

  4. Behavioral determination of stimulus pair discrimination of auditory acoustic and electrical stimuli using a classical conditioning and heart-rate approach.

    Science.gov (United States)

    Morgan, Simeon J; Paolini, Antonio G

    2012-06-06

    Acute animal preparations have been used in research prospectively investigating electrode designs and stimulation techniques for integration into neural auditory prostheses, such as auditory brainstem implants and auditory midbrain implants. While acute experiments can give initial insight to the effectiveness of the implant, testing the chronically implanted and awake animals provides the advantage of examining the psychophysical properties of the sensations induced using implanted devices. Several techniques such as reward-based operant conditioning, conditioned avoidance, or classical fear conditioning have been used to provide behavioral confirmation of detection of a relevant stimulus attribute. Selection of a technique involves balancing aspects including time efficiency (often poor in reward-based approaches), the ability to test a plurality of stimulus attributes simultaneously (limited in conditioned avoidance), and measure reliability of repeated stimuli (a potential constraint when physiological measures are employed). Here, a classical fear conditioning behavioral method is presented which may be used to simultaneously test both detection of a stimulus, and discrimination between two stimuli. Heart-rate is used as a measure of fear response, which reduces or eliminates the requirement for time-consuming video coding for freeze behaviour or other such measures (although such measures could be included to provide convergent evidence). Animals were conditioned using these techniques in three 2-hour conditioning sessions, each providing 48 stimulus trials. Subsequent 48-trial testing sessions were then used to test for detection of each stimulus in presented pairs, and test discrimination between the member stimuli of each pair. This behavioral method is presented in the context of its utilisation in auditory prosthetic research. The implantation of electrocardiogram telemetry devices is shown. Subsequent implantation of brain electrodes into the Cochlear

  5. [Testing of the effect of classic conditioning stimuli in human experiment by means of the transfer of control paradigm].

    Science.gov (United States)

    Wolter, J

    1999-01-01

    Pavlovian conditioning in animals is often evaluated by means of transfer of control experiments. With human subjects, however, only very few studies have been conducted and the outcomes were often not in accordance with theoretical explanations based on studies with animals. A theoretical framework is presented that tries to integrate the results of the human conditioning paradigm and the animal conditioning paradigm as well, with reference to the well-known Yerkes-Dodson law. The experimental study with human subjects (N = 24) confirmed the predictions out of this framework, when a procedure similar to animal research is applied.

  6. Effects of hippocampal state-contingent trial presentation on hippocampus-dependent nonspatial classical conditioning and extinction.

    Science.gov (United States)

    Nokia, Miriam S; Wikgren, Jan

    2014-04-23

    Hippocampal local field potentials are characterized by two mutually exclusive states: one characterized by regular θ oscillations (∼4-8 Hz) and the other by irregular sharp-wave ripples. Presenting stimuli during dominant θ oscillations leads to expedited learning, suggesting that θ indexes a state in which encoding is most effective. However, ripple-contingent training also expedites learning, suggesting that any discrete brain state, much like the external context, can affect learning. We trained adult rabbits in trace eyeblink conditioning, a hippocampus-dependent nonspatial task, followed by extinction. Trials were delivered either in the presence or absence of θ or regardless of hippocampal state. Conditioning in the absence of θ led to more animals learning, although learning was slower compared with a yoked control group. Contrary to expectations, conditioning in the presence of θ did not affect learning. However, extinction was expedited both when it was conducted contingent on θ and when it was conducted in a state contrary to that used to trigger trials during conditioning. Strong phase-locking of hippocampal θ-band responses to the conditioned stimulus early on during conditioning predicted good learning. No such connection was observed during extinction. Our results suggest that any consistent hippocampal oscillatory state can potentially be used to regulate learning. However, the effects depend on the specific state and task at hand. Finally, much like the external environment, the ongoing neural state appears to act as a context for learning and memory retrieval.

  7. 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.

  8. Olfactory dysfunction in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    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

  9. 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

  10. 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.

  11. Sox10-dependent neural crest origin of olfactory microvillous neurons in zebrafish.

    Science.gov (United States)

    Saxena, Ankur; Peng, Brian N; Bronner, Marianne E

    2013-03-19

    The sense of smell in vertebrates is detected by specialized sensory neurons derived from the peripheral nervous system. Classically, it has been presumed that the olfactory placode forms all olfactory sensory neurons. In contrast, we show that the cranial neural crest is the primary source of microvillous sensory neurons within the olfactory epithelium of zebrafish embryos. Using photoconversion-based fate mapping and live cell tracking coupled with laser ablation, we followed neural crest precursors as they migrated from the neural tube to the nasal cavity. A subset that coexpressed Sox10 protein and a neurogenin1 reporter ingressed into the olfactory epithelium and differentiated into microvillous sensory neurons. Timed loss-of-function analysis revealed a critical role for Sox10 in microvillous neurogenesis. Taken together, these findings directly demonstrate a heretofore unknown contribution of the cranial neural crest to olfactory sensory neurons in zebrafish and provide important insights into the assembly of the nascent olfactory system. DOI:http://dx.doi.org/10.7554/eLife.00336.001.

  12. Two-stage AMPA receptor trafficking in classical conditioning and selective role for glutamate receptor subunit 4 (tGluA4) flop splice variant.

    Science.gov (United States)

    Zheng, Zhaoqing; Sabirzhanov, Boris; Keifer, Joyce

    2012-07-01

    Previously, we proposed a two-stage model for an in vitro neural correlate of eyeblink classical conditioning involving the initial synaptic incorporation of glutamate receptor A1 (GluA1)-containing α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid type receptors (AMPARs) followed by delivery of GluA4-containing AMPARs that support acquisition of conditioned responses. To test specific elements of our model for conditioning, selective knockdown of GluA4 AMPAR subunits was used using small-interfering RNAs (siRNAs). Recently, we sequenced and characterized the GluA4 subunit and its splice variants from pond turtles, Trachemys scripta elegans (tGluA4). Analysis of the relative abundance of mRNA expression by real-time RT-PCR showed that the flip/flop variants of tGluA4, tGluA4c, and a novel truncated variant tGluA4trc1 are major isoforms in the turtle brain. Here, transfection of in vitro brain stem preparations with anti-tGluA4 siRNA suppressed conditioning, tGluA4 mRNA and protein expression, and synaptic delivery of tGluA4-containing AMPARs but not tGluA1 subunits. Significantly, transfection of abducens motor neurons by nerve injections of tGluA4 flop rescue plasmid prior to anti-tGluA4 siRNA application restored conditioning and synaptic incorporation of tGluA4-containing AMPARs. In contrast, treatment with rescue plasmids for tGluA4 flip or tGluA4trc1 failed to rescue conditioning. Finally, treatment with a siRNA directed against GluA1 subunits inhibited conditioning and synaptic delivery of tGluA1-containing AMPARs and importantly, those containing tGluA4. These data strongly support our two-stage model of conditioning and our hypothesis that synaptic incorporation of tGluA4-containing AMPARs underlies the acquisition of in vitro classical conditioning. Furthermore, they suggest that tGluA4 flop may have a critical role in conditioning mechanisms compared with the other tGluA4 splice variants.

  13. Classics Online.

    Science.gov (United States)

    Clayman, Dee L.

    1995-01-01

    Appraises several databases devoted to classical literature. Thesaurus Linguae Graecae (TLG) contains the entire extant corpus of ancient Greek literature, including works on lexicography and historiography, extending into the 15th century. Other works awaiting completion are the Database of Classical Bibliography and a CD-ROM pictorial dictionary…

  14. Eyeblink classical conditioning and interpositus nucleus activity are disrupted in adult rats exposed to ethanol as neonates.

    Science.gov (United States)

    Green, John T; Johnson, Timothy B; Goodlett, Charles R; Steinmetz, Joseph E

    2002-01-01

    Neonatal exposure to ethanol in rats, during the period of brain development comparable to that of the human third trimester, produces significant, dose-dependent cell loss in the cerebellum and deficits in coordinated motor performance. These rats are also impaired in eyeblink conditioning as weanlings and as adults. The current study examined single-unit neural activity in the interpositus nucleus of the cerebellum in adults following neonatal binge ethanol exposure. Group Ethanol received alcohol doses of 5.25 g/kg/day on postnatal days 4-9. Group Sham Intubated underwent acute intragastric intubation on postnatal days 4-9 but did not receive any infusions. Group Unintubated Control (from separate litters) did not receive any intubations. When rats were 3-7 mo old, pairs of extracellular microelectrodes were implanted in the region of the interpositus nucleus. Beginning 1 wk later, the rats were given either 100 paired or 190 unpaired trials per day for 10 d followed by 4 d of 100 conditioned stimulus (CS)-alone trials per day. As in our previous study, conditioned response acquisition in Group Ethanol rats was impaired. In addition, by session 5 of paired acquisition, Group Sham Intubated and Group Unintubated Control showed significant increases in interpositus nucleus activity, relative to baseline, in the CS-unconditioned stimulus interval. In contrast, Group Ethanol failed to show significant changes in interpositus nucleus activity until later in training. These results indicate that the disruption in eyeblink conditioning after early exposure to ethanol is reflected in alterations in interpositus nucleus activity.

  15. Eyeblink Classical Conditioning and Interpositus Nucleus Activity Are Disrupted in Adult Rats Exposed to Ethanol as Neonates

    Science.gov (United States)

    Green, John T.; Johnson, Timothy B.; Goodlett, Charles R.; Steinmetz, Joseph E.

    2002-01-01

    Neonatal exposure to ethanol in rats, during the period of brain development comparable to that of the human third trimester, produces significant, dose-dependent cell loss in the cerebellum and deficits in coordinated motor performance. These rats are also impaired in eyeblink conditioning as weanlings and as adults. The current study examined single-unit neural activity in the interpositus nucleus of the cerebellum in adults following neonatal binge ethanol exposure. Group Ethanol received alcohol doses of 5.25 g/kg/day on postnatal days 4–9. Group Sham Intubated underwent acute intragastric intubation on postnatal days 4–9 but did not receive any infusions. Group Unintubated Control (from separate litters) did not receive any intubations. When rats were 3–7 mo old, pairs of extracellular microelectrodes were implanted in the region of the interpositus nucleus. Beginning 1 wk later, the rats were given either 100 paired or 190 unpaired trials per day for 10 d followed by 4 d of 100 conditioned stimulus (CS)-alone trials per day. As in our previous study, conditioned response acquisition in Group Ethanol rats was impaired. In addition, by session 5 of paired acquisition, Group Sham Intubated and Group Unintubated Control showed significant increases in interpositus nucleus activity, relative to baseline, in the CS–unconditioned stimulus interval. In contrast, Group Ethanol failed to show significant changes in interpositus nucleus activity until later in training. These results indicate that the disruption in eyeblink conditioning after early exposure to ethanol is reflected in alterations in interpositus nucleus activity. PMID:12359839

  16. Modulation of the N170 with Classical Conditioning: The Use of Emotional Imagery and Acoustic Startle in Healthy and Depressed Participants.

    Science.gov (United States)

    Camfield, David A; Mills, Jessica; Kornfeld, Emma J; Croft, Rodney J

    2016-01-01

    Recent studies have suggested that classical conditioning may be capable of modulating early sensory processing in the human brain, and that there may be differences in the magnitude of the conditioned changes for individuals with major depressive disorder. The effect of conditioning on the N170 event-related potential was investigated using neutral faces as conditioned stimuli (CS+) and emotional imagery and acoustic startle as unconditioned stimuli (UCS). In the first experiment, electroencephalogram was recorded from 24 undergraduate students (M = 21.07 years, SD = 3.38 years) under the following conditions: (i) CS+/aversive imagery, (ii) CS+/aversive imagery and acoustic startle, (iii) CS+/acoustic startle, and (iv) CS+/pleasant imagery. The amplitude of the N170 was enhanced following conditioning with aversive imagery as well as acoustic startle. In the second experiment, 26 healthy control participants were tested (17 females and 9 males, age M = 25.97 years, SD = 9.42) together with 18 depressed participants (13 females and 5 males, age M = 23.26 years, SD = 4.01) and three conditions were used: CS+/aversive imagery, CS+/pleasant imagery, and CS-. N170 amplitude at P7 was increased for the CS+/aversive condition in comparison to CS- in the conditioning blocks versus baseline. No differences between depressed and healthy participants were found. Across both experiments, evaluative conditioning was absent. It was concluded that aversive UCS are capable of modulating early sensory processing of faces, although further research is also warranted in regards to positive UCS.

  17. Classical integrability

    Science.gov (United States)

    Torrielli, Alessandro

    2016-08-01

    We review some essential aspects of classically integrable systems. The detailed outline of the sections consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schrödinger model, principal chiral field); 4. Features of classical r-matrices: Belavin-Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel’fand-Levitan-Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  18. Concentration-invariant odor representation in the olfactory system by presynaptic inhibition.

    Science.gov (United States)

    Zhang, Danke; Li, Yuanqing; Wu, Si

    2013-01-01

    The present study investigates a network model for implementing concentration-invariant representation for odors in the olfactory system. The network consists of olfactory receptor neurons, projection neurons, and inhibitory local neurons. Receptor neurons send excitatory inputs to projection neurons, which are modulated by the inhibitory inputs from local neurons. The modulation occurs at the presynaptic site from a receptor neuron to a projection one, leading to the operation of divisive normalization. The responses of local interneurons are determined by the total activities of olfactory receptor neurons. We find that with a proper parameter condition, the responses of projection neurons become effectively independent of the odor concentration. Simulation results confirm our theoretical analysis.

  19. 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.

  20. 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).

  1. Limbic system development underlies the emergence of classical fear conditioning during the third and fourth weeks of life in the rat.

    Science.gov (United States)

    Deal, Alex L; Erickson, Kristen J; Shiers, Stephanie I; Burman, Michael A

    2016-04-01

    Classical fear conditioning creates an association between an aversive stimulus and a neutral stimulus. Although the requisite neural circuitry is well understood in mature organisms, the development of these circuits is less well studied. The current experiments examine the ontogeny of fear conditioning and relate it to neuronal activation assessed through immediate early gene (IEG) expression in the amygdala, hippocampus, perirhinal cortex, and hypothalamus of periweanling rats. Rat pups were fear conditioned, or not, during the third or fourth weeks of life. Neuronal activation was assessed by quantifying expression of FBJ osteosarcoma oncogene (FOS) using immunohistochemistry (IHC) in Experiment 1. Fos and early growth response gene-1 (EGR1) expression was assessed using qRT-PCR in Experiment 2. Behavioral data confirm that both auditory and contextual fear continue to emerge between PD 17 and 24. The IEG expression data are highly consistent with these behavioral results. IHC results demonstrate significantly more FOS protein expression in the basal amygdala of fear-conditioned PD 23 subjects compared to control subjects, but no significant difference at PD 17. qRT-PCR results suggest specific activation of the amygdala only in older subjects during auditory fear expression. A similar effect of age and conditioning status was also observed in the perirhinal cortex during both contextual and auditory fear expression. Overall, the development of fear conditioning occurring between the third and fourth weeks of life appears to be at least partly attributable to changes in activation of the amygdala and perirhinal cortex during fear conditioning or expression. (PsycINFO Database Record

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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

  4. Conditions for the Existence and Stability of the Continuous Attractor in the Classical XY Model with an Associative-Memory-Type Interaction

    Science.gov (United States)

    Yoshida, Risa; Kimoto, Tomoyuki; Uezu, Tatsuya

    2017-03-01

    We analyze the structure of attractors in the classical XY model with an associative-memory-type interaction by the statistical mechanical method. Previously, it was found that when patterns are uncorrelated, points on a path connecting two memory patterns in the space of the order parameters are solutions of the saddle point equations (SPEs) in the case that p is O(1) irrespective of N and N ≫ 1, where p and N are the numbers of patterns and spins, respectively. This state is called the continuous attractor (CA). In this paper, we clarify the conditions for the existence and stability of the CA with and without the correlation a (0 ≤ a 0, we numerically study the case that patterns are subject to external noise and find that pc increases as the noise amplitude increases.

  5. An embodied biologically constrained model of foraging: from classical and operant conditioning to adaptive real-world behavior in DAC-X.

    Science.gov (United States)

    Maffei, Giovanni; Santos-Pata, Diogo; Marcos, Encarni; Sánchez-Fibla, Marti; Verschure, Paul F M J

    2015-12-01

    Animals successfully forage within new environments by learning, simulating and adapting to their surroundings. The functions behind such goal-oriented behavior can be decomposed into 5 top-level objectives: 'how', 'why', 'what', 'where', 'when' (H4W). The paradigms of classical and operant conditioning describe some of the behavioral aspects found in foraging. However, it remains unclear how the organization of their underlying neural principles account for these complex behaviors. We address this problem from the perspective of the Distributed Adaptive Control theory of mind and brain (DAC) that interprets these two paradigms as expressing properties of core functional subsystems of a layered architecture. In particular, we propose DAC-X, a novel cognitive architecture that unifies the theoretical principles of DAC with biologically constrained computational models of several areas of the mammalian brain. DAC-X supports complex foraging strategies through the progressive acquisition, retention and expression of task-dependent information and associated shaping of action, from exploration to goal-oriented deliberation. We benchmark DAC-X using a robot-based hoarding task including the main perceptual and cognitive aspects of animal foraging. We show that efficient goal-oriented behavior results from the interaction of parallel learning mechanisms accounting for motor adaptation, spatial encoding and decision-making. Together, our results suggest that the H4W problem can be solved by DAC-X building on the insights from the study of classical and operant conditioning. Finally, we discuss the advantages and limitations of the proposed biologically constrained and embodied approach towards the study of cognition and the relation of DAC-X to other cognitive architectures.

  6. Pairing-specific long-term depression of Purkinje cell excitatory postsynaptic potentials results from a classical conditioning procedure in the rabbit cerebellar slice.

    Science.gov (United States)

    Schreurs, B G; Oh, M M; Alkon, D L

    1996-03-01

    1. Using a rabbit cerebellar slice preparation, we stimulated a classical conditioning procedure by stimulating parallel fiber inputs to Purkinje cells with the use of a brief, high-frequency train of eight constant-current pulses 80 ms before climbing fiber inputs to the same Purkinje cell were stimulated with the use of a brief, lower frequency train of three constant-current pulses. In all experiments, we assessed the effects of stimulation by measuring the peak amplitude of Purkinje cell excitatory postsynaptic potentials (EPSPs) to single parallel fiber test pulses. 2. Intradendritically recorded Purkinje cell EPSPs underwent a long-term (> 20 min) reduction in peak amplitude (30%) after paired stimulation of the parallel and climbing fibers but not after unpaired or parallel fiber alone stimulation. We call this phenomenon pairing-specific long-term depression (PSD). 3. Facilitation of the peak amplitude of a second EPSP elicited by a parallel fiber train occurred both before and after paired stimulation suggesting that the locus of depression was not presynaptic. Depression of the peak amplitude of a depolarizing response to focal application of glutamate following pairings of parallel and climbing fiber stimulation added support to a suggested postsynaptic locus of the PSD effect. 4. The application of aniracetam potentiated EPSP peak amplitude by 40%, but these values returned to baseline as a result of pairings. With the removal of aniracetam from the bath 20 min after pairings, normal levels of pairing-specific EPSP depression were observed, indicating that the effect did not result from direct desensitization of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-proprionic acid (AMPA) receptors. 5. Incubation of slices in the protein kinase inhibitor H-7 potentiated EPSP peak amplitudes slightly (9%), but peak amplitudes returned to baseline levels after pairings. The net reduction in EPSP peak amplitude of classical conditioning.

  7. 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.

  8. Oligomeric amyloid-{beta} inhibits the proteolytic conversion of brain-derived neurotrophic factor (BDNF), AMPA receptor trafficking, and classical conditioning.

    Science.gov (United States)

    Zheng, Zhaoqing; Sabirzhanov, Boris; Keifer, Joyce

    2010-11-01

    Amyloid-β (Aβ) peptide is thought to have a significant role in the progressive memory loss observed in patients with Alzheimer disease and inhibits synaptic plasticity in animal models of learning. We previously demonstrated that brain-derived neurotrophic factor (BDNF) is critical for synaptic AMPA receptor delivery in an in vitro model of eyeblink classical conditioning. Here, we report that acquisition of conditioned responses was significantly attenuated by bath application of oligomeric (200 nm), but not fibrillar, Aβ peptide. Western blotting revealed that BDNF protein expression during conditioning is significantly reduced by treatment with oligomeric Aβ, as were phosphorylation levels of cAMP-response element-binding protein (CREB), Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV), and ERK. However, levels of PKA and PKCζ/λ were unaffected, as was PDK-1. Protein localization studies using confocal imaging indicate that oligomeric Aβ, but not fibrillar or scrambled forms, suppresses colocalization of GluR1 and GluR4 AMPA receptor subunits with synaptophysin, indicating that trafficking of these subunits to synapses during the conditioning procedure is blocked. In contrast, coapplication of BDNF with oligomeric Aβ significantly reversed these findings. Interestingly, a tolloid-like metalloproteinase in turtle, tTLLs (turtle tolloid-like protein), which normally processes the precursor proBDNF into mature BDNF, was found to degrade oligomeric Aβ into small fragments. These data suggest that an Aβ-induced reduction in BDNF, perhaps due to interference in the proteolytic conversion of proBDNF to BDNF, results in inhibition of synaptic AMPA receptor delivery and suppression of the acquisition of conditioning.

  9. First assessment of classical swine fever marker vaccine candidate CP7_E2alf for oral immunization of wild boar under field conditions.

    Science.gov (United States)

    Feliziani, Francesco; Blome, Sandra; Petrini, Stefano; Giammarioli, Monica; Iscaro, Carmen; Severi, Giulio; Convito, Luca; Pietschmann, Jana; Beer, Martin; De Mia, Gian Mario

    2014-04-11

    Oral vaccination against classical swine fever (CSF) is a potent tool to control disease outbreaks in wild boar. So far, vaccination campaigns have been carried out using live attenuated vaccines that do not allow serological differentiation of infected from vaccinated animals (DIVA). Although this drawback is acceptable for wild boar, the use of marker vaccines would facilitate studies on disease and vaccination dynamics. Recently, the CSF marker vaccine candidate CP7_E2alf was assessed for oral immunization under laboratory conditions. Promising results prompted efforts to study the vaccine candidate under field conditions and in bait formulation. In this context, two oral vaccination campaigns were carried out with CP7_E2alf bait vaccines in two areas called 'faunistic-hunting farms' in the region of Umbria, Italy. One campaign was conducted using single vaccination, the second with the routinely employed double vaccination strategy. Both campaigns were carried out before concerted hunting actions were performed. Bait uptake, vaccine virus detection and antibody responses were assessed along with inspections upon gutting. As a comparator, seven wild boar were hand-fed with baits under laboratory conditions. In the field, bait uptake ranged from 63.7% to 98.7%, whereas antibody prevalence reached only 33.3-35.1%. The marker serology showed a strong influence of sample quality on the test outcome with a total of 85% of samples being classified correctly. Vaccine virus was not detectable. Under hand feeding conditions, six out of seven wild boar took up at least one bait, and five of them showed detectable antibody levels seven weeks after vaccination. These results were supplemented by stability tests. Appropriate stability of vaccine virus was shown both under field and laboratory conditions. In total, most results were in line with our expectations. However, optimization of the DIVA assay has to be attempted in the future.

  10. Effects of 20 mg oral Δ9-tetrahydrocannabinol on the olfactory function of healthy volunteers*

    Science.gov (United States)

    Walter, Carmen; Oertel, Bruno G; Ludyga, Dagmar; Ultsch, Alfred; Hummel, Thomas; Lötsch, Jörn

    2014-01-01

    Aims Olfactory loss impairs the patient's quality of life. In individualized therapies, olfactory drug effects gain clinical importance. Molecular evidence suggests that among drugs with potential olfactory effects is Δ9-tetrahydrocannabinol (THC), which is approved for several indications, including neuropathic pain or analgesia in cancer patients. The present study aimed at assessing the olfactory effects of THC to be expected during analgesic treatment. Methods The effects of 20 mg oral THC on olfaction were assessed in a placebo-controlled, randomized cross-over study in healthy volunteers. Using an established olfactory test (Sniffin' Sticks), olfactory thresholds, odour discrimination and odour identification were assessed in 15 subjects at baseline and 2 h after THC administration. Results Δ9-Tetrahydrocannabinol impaired the performance of subjects (n = 15) in the olfactory test. Specifically, olfactory thresholds were increased and odour discrimination performance was reduced. This resulted in a significant drop in composite threshold, discrimination, identification (TDI) olfactory score by 5.5 points (from 37.7 ± 4.2 to 32.2 ± 5.6, 95% confidence interval for differences THC vs. placebo, −7.8 to −2.0, P = 0.003), which is known to be a subjectively perceptible impairment of olfactory function. Conclusions Considering the resurgence of THC in medical use for several pathological conditions, the present results indicate that THC-based analgesics may be accompanied by subjectively noticeable reductions in olfactory acuity. In particular, for patients relying on their sense of smell, this might be relevant information for personalized therapy strategies. PMID:24802974

  11. Classical Mechanics

    OpenAIRE

    Gallavotti, Giovanni

    2012-01-01

    This is the English version of a friendly graduate course on Classical Mechanics, containing about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. For the Spanish version, see physics/9906066

  12. Investigation on reactivity of non-classical carbenes with sterically hindered Lewis acid, B(C6F5)3 under inert and open conditions

    Indian Academy of Sciences (India)

    Arunabha Thakur; Pavan K Vardhanapu; Gonela Vijaykumar; Sushil Ranjan Bhatta

    2016-04-01

    Reactions of B(C6F5)3 with abnormal N-heterocyclic carbene (NHC), L1 and cyclic (alkyl)(amino) carbene (AAC), L2 in the presence of moisture as well as in its absence, have been investigated in toluene. Reaction of NHC with 1 equivalent of B(C6F5)3 under inert condition produced classical Lewis acid-base adduct, [L1.B(C6F5)3], 1. Further, probing the same reaction with cyclic (alkyl)(amino) carbene (AAC), having different electronic property, led to the isolation of [L2.B(C6F5)3], 2 under inert condition. Interestingly, reaction of NHC or AAC with 1 equivalent of B(C6F5)3 in the presence of moisture resulted in water splitting leading to the formation of [L1-H][(OH)B(C6F5)3], 3 and [L2-H][(OH)B(C6F5)3, 4. All these compounds (1-4) were characterized in solution by 1H, 13C, 19F and 11B NMR spectroscopy. Additionally, the solid-state structures were unambiguously established by crystallographic analysis of compounds 1-4.

  13. Ion mobility spectrometry versus classical physico-chemical analysis for assessing the shelf life of extra virgin olive oil according to container type and storage conditions.

    Science.gov (United States)

    Garrido-Delgado, Rocío; Dobao-Prieto, M Mar; Arce, Lourdes; Aguilar, Joaquín; Cumplido, José L; Valcárcel, Miguel

    2015-03-04

    An experimental study was conducted to assess the stability of a single-variety (Arbequina) extra virgin olive oil (EVOO) as a function of container type and storage conditions over a period of 11 months. EVOO quality was assessed by using ion mobility spectrometry (IMS), which provides increased simplicity, expeditiousness, and relative economy. The results were compared with the ones obtained by using the official method based on classical physico-chemical analysis. Bag-in-box, metal, dark glass, clear glass, and polyethylene terephthalate containers holding EVOO were opened on a periodic basis for sampling to simulate domestic use; in parallel, other containers were kept closed until analysis to simulate the storage conditions on market shelves. The results of the physico-chemical and instrumental analyses led to similar conclusions. Thus, samples packaged in bag-in-box containers preserved oil quality for 11 months, better than other container types. The HS-GC-IMS results confirm that 2-heptenal and 1-penten-3-one are two accurate markers of EVOO quality.

  14. Modulation of olfactory sensitivity and glucose sensing by the feeding state in obese Zucker rats.

    Directory of Open Access Journals (Sweden)

    Pascaline eAimé

    2014-09-01

    Full Text Available The Zucker fa/fa rat has been widely used as an animal model to study obesity, since it recapitulates most of its behavioral and metabolic dysfunctions, such as hyperphagia, hyperglycemia and insulin resistance. Although it is well established that olfaction is under nutritional and hormonal influences, little is known about the impact of metabolic dysfunctions on olfactory performances and glucose-sensing in the olfactory system of the obese Zucker rat. In the present study, using a behavioral paradigm based on a conditioned olfactory aversion, we have shown that both obese and lean Zucker rats have a better olfactory sensitivity when they are fasted than when they are satiated. Interestingly, the obese Zucker rats displayed a higher olfactory sensitivity than their lean controls. By investigating the molecular mechanisms involved in glucose-sensing in the olfactory system, we demonstrated that sodium-coupled glucose transporters 1 (SGLT1 and insulin dependent glucose transporters 4 (GLUT4 are both expressed in the olfactory bulb (OB. By comparing the expression of GLUT4 and SGLT1 in OB of obese and lean Zucker rats, we found that only SGLT1 is regulated in genotype-dependent manner. Next, we used glucose oxidase biosensors to simultaneously measure in vivo the extracellular fluid glucose concentrations ([Gluc]ECF in the OB and the cortex. Under metabolic steady state, we have determined that the OB contained twice the amount of glucose found in the cortex. In both regions, the [Gluc]ECF was 2 fold higher in obese rats compared to their lean controls. Under induced dynamic glycemia conditions, insulin injection produced a greater decrease of [Gluc]ECF in the OB than in the cortex. Glucose injection did not affect OB [Gluc]ECF in Zucker fa/fa rats. In conclusion, these results emphasize the importance of glucose for the OB network function and provide strong arguments towards establishing the OB glucose-sensing as a key factor for sensory

  15. 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

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

    Science.gov (United States)

    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.

  17. 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.

  18. Bifurcation analysis of oscillating network model of pattern recognition in the rabbit olfactory bulb

    Science.gov (United States)

    Baird, Bill

    1986-08-01

    A neural network model describing pattern recognition in the rabbit olfactory bulb is analysed to explain the changes in neural activity observed experimentally during classical Pavlovian conditioning. EEG activity recorded from an 8×8 arry of 64 electrodes directly on the surface on the bulb shows distinct spatial patterns of oscillation that correspond to the animal's recognition of different conditioned odors and change with conditioning to new odors. The model may be considered a variant of Hopfield's model of continuous analog neural dynamics. Excitatory and inhibitory cell types in the bulb and the anatomical architecture of their connection requires a nonsymmetric coupling matrix. As the mean input level rises during each breath of the animal, the system bifurcates from homogenous equilibrium to a spatially patterned oscillation. The theory of multiple Hopf bifurcations is employed to find coupled equations for the amplitudes of these unstable oscillatory modes independent of frequency. This allows a view of stored periodic attractors as fixed points of a gradient vector field and thereby recovers the more familiar dynamical systems picture of associative memory.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Improving intranasal delivery of neurological nanomedicine to the olfactory region using magnetophoretic guidance of microsphere carriers

    Directory of Open Access Journals (Sweden)

    Xi J

    2015-02-01

    Full Text Available Jinxiang Xi,1 Ze Zhang,1 Xiuhua A Si21School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI, 2Department of Mechanical Engineering, California Baptist University, Riverside, CA, USABackground: Although direct nose-to-brain drug delivery has multiple advantages, its application is limited by the extremely low delivery efficiency (<1% to the olfactory region where drugs can enter the brain. It is crucial to developing new methods that can deliver drug particles more effectively to the olfactory region.Materials and methods: We introduced a delivery method that used magnetophoresis to improve olfactory delivery efficiency. The performance of the proposed method was assessed numerically in an image-based human nose model. Influences of the magnet layout, magnet strength, drug-release position, and particle diameter on the olfactory dosage were examined.Results and discussion: Results showed that particle diameter was a critical factor in controlling the motion of nasally inhaled ferromagnetic drug particles. The optimal particle size was found to be approximately 15 µm for effective magnetophoretic guidance while avoiding loss of particles to the walls in the anterior nose. Olfactory delivery efficiency was shown to be sensitive to the position and strength of magnets and the release position of drug particles. The results of this study showed that clinically significant olfactory doses (up to 45% were feasible using the optimal combination of magnet layout, selective drug release, and microsphere-carrier diameter. A 64-fold-higher delivery of dosage was predicted in the magnetized nose compared to the control case, which did not have a magnetic field. However, the sensitivity of olfactory dosage to operating conditions and the unstable nature of magnetophoresis make controlled guidance of nasally inhaled aerosols still highly challenging.Keywords: direct nose–brain delivery, olfactory deposition, magnetophoretic

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

    Directory of Open Access Journals (Sweden)

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

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    Adrien eFrançois

    2013-12-01

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

  6. Olfactory nerve--a novel invasion route of Neisseria meningitidis to reach the meninges.

    Science.gov (United States)

    Sjölinder, Hong; Jonsson, Ann-Beth

    2010-11-18

    Neisseria meningitidis is a human-specific pathogen with capacity to cause septic shock and meningitis. It has been hypothesized that invasion of the central nervous system (CNS) is a complication of a bacteremic condition. In this study, we aimed to characterize the invasion route of N. meningitidis to the CNS. Using an intranasally challenged mouse disease model, we found that twenty percent of the mice developed lethal meningitis even though no bacteria could be detected in blood. Upon bacterial infection, epithelial lesions and redistribution of intracellular junction protein N-cadherin were observed at the nasal epithelial mucosa, especially at the olfactory epithelium, which is functionally and anatomically connected to the CNS. Bacteria were detected in the submucosa of the olfactory epithelium, along olfactory nerves in the cribriform plate, at the olfactory bulb and subsequently at the meninges and subarachnoid space. Furthermore, our data suggest that a threshold level of bacteremia is required for the development of meningococcal sepsis. Taken together, N. meningitidis is able to pass directly from nasopharynx to meninges through the olfactory nerve system. This study enhances our understanding how N. meningitidis invades the meninges. The nasal olfactory nerve system may be a novel target for disease prevention that can improve outcome and survival.

  7. Olfactory nerve--a novel invasion route of Neisseria meningitidis to reach the meninges.

    Directory of Open Access Journals (Sweden)

    Hong Sjölinder

    Full Text Available Neisseria meningitidis is a human-specific pathogen with capacity to cause septic shock and meningitis. It has been hypothesized that invasion of the central nervous system (CNS is a complication of a bacteremic condition. In this study, we aimed to characterize the invasion route of N. meningitidis to the CNS. Using an intranasally challenged mouse disease model, we found that twenty percent of the mice developed lethal meningitis even though no bacteria could be detected in blood. Upon bacterial infection, epithelial lesions and redistribution of intracellular junction protein N-cadherin were observed at the nasal epithelial mucosa, especially at the olfactory epithelium, which is functionally and anatomically connected to the CNS. Bacteria were detected in the submucosa of the olfactory epithelium, along olfactory nerves in the cribriform plate, at the olfactory bulb and subsequently at the meninges and subarachnoid space. Furthermore, our data suggest that a threshold level of bacteremia is required for the development of meningococcal sepsis. Taken together, N. meningitidis is able to pass directly from nasopharynx to meninges through the olfactory nerve system. This study enhances our understanding how N. meningitidis invades the meninges. The nasal olfactory nerve system may be a novel target for disease prevention that can improve outcome and survival.

  8. The effect of verbal context on olfactory neural responses.

    Science.gov (United States)

    Bensafi, Moustafa; Croy, Ilona; Phillips, Nicola; Rouby, Catherine; Sezille, Caroline; Gerber, Johannes; Small, Dana M; Hummel, Thomas

    2014-03-01

    Odor names refer usually to "source" object categories. For example, the smell of rose is often described with its source category (flower). However, linguistic studies suggest that odors can also be named with labels referring to categories of "practices". This is the case when rose odor is described with a verbal label referring to its use in fragrance practices ("body lotion," cosmetic for example). It remains unknown whether naming an odor by its practice category influences olfactory neural responses differently than that observed when named with its source category. The aim of this study was to investigate this question. To this end, functional MRI was used in a within-subjects design comparing brain responses to four different odors (peach, chocolate, linden blossom, and rose) under two conditions whereby smells were described either (1) with their source category label (food and flower) or (2) with a practice category label (body lotion). Both types of labels induced activations in secondary olfactory areas (orbitofrontal cortex), whereas only the source label condition induced activation in the cingulate cortex and the insula. In summary, our findings offer a new look at olfactory perception by indicating differential brain responses depending on whether odors are named according to their source or practice category.

  9. 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.

  10. 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.

  11. Discrete Classical Electromagnetic Fields

    CERN Document Server

    De Souza, M M

    1997-01-01

    The classical electromagnetic field of a spinless point electron is described in a formalism with extended causality by discrete finite transverse point-vector fields with discrete and localized point interactions. These fields are taken as a classical representation of photons, ``classical photons". They are all transversal photons; there are no scalar nor longitudinal photons as these are definitely eliminated by the gauge condition. The angular distribution of emitted photons coincides with the directions of maximum emission in the standard formalism. The Maxwell formalism and its standard field are retrieved by the replacement of these discrete fields by their space-time averages, and in this process scalar and longitudinal photons are necessarily created and added. Divergences and singularities are by-products of this averaging process. This formalism enlighten the meaning and the origin of the non-physical photons, the ones that violate the Lorentz condition in manifestly covariant quantization methods.

  12. 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

  13. [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.

  14. [Classical taxomomies].

    Science.gov (United States)

    Liubarskiĭ, G Iu

    2006-01-01

    The sequence of classic paradigms in taxonomy that partly replaced each other and partly co-exist is given as follows: the theory of "organ and organism similarity", the naturalistic theory, the descriptive theory, and the phylogenetic theory. The naturalistic classics accepted the notion of "the plan of creation". The rejection of appealing to this plan brought forth certain problems in the formulation of the purpose of taxonomy; these problems were differently solved by the descriptive and the phylogenetic classic traditions. The difficulties of the current paradigms arising from the loss of a "strong purpose", a problem to be solved by taxonomists that is to be clear and interesting to a wide range of non-professionals. The paradox of formalization led to the losing of content of the methods due to their formalization. To attract attention to taxonomy, a new "image of the results" of its work that would be interesting to the non-professionals is necessary. The co-existence of different methods of reseach applied to different groups of facts leads to the loss of integrity of the research. It is not only that the taxon becomes a hypothesis and such hypotheses multiply. The comparison of these hypotheses is problematic, because each of them is supported by its own independent scope of facts. Because of the existence of a fundamental meronotaxonomic discrepancy, taxonomic systems based on different groups of characters appear to be incomparable, being rather systems of characters than systems of taxa. Systems of characters are not directly comparable with each other; they can be compared only through appealing to taxa, but taxa themselves exist only in the form of a number of hypotheses. Consequently, each separate taxonomic approach creates its own nature, its own subject of research. Therefore, it is necessary to describe the subject of research correctly (and indicate the purpose of research), as well as to distinguish clearly between results achieved through

  15. 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.

  16. [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.

  17. The therapeutic potential of human olfactory-derived stem cells.

    Science.gov (United States)

    Marshall, C T; Lu, C; Winstead, W; Zhang, X; Xiao, M; Harding, G; Klueber, K M; Roisen, F J

    2006-06-01

    Stem cells from fetal and adult central nervous system have been isolated and characterized, providing populations for potential replacement therapy for traumatic injury repair and neurodegenerative diseases. The regenerative capacity of the olfactory system has attracted scientific interest. Studies focusing on animal and human olfactory bulb ensheathing cells (OECs) have heightened the expectations that OECs can enhance axonal regeneration and repair demyelinating diseases. Harvest of OECs from the olfactory bulb requires highly invasive surgery, which is a major obstacle. In contrast, olfactory epithelium (OE) has a unique regenerative capacity and is readily accessible from its location in the nasal cavity, allowing for harvest without lasting damage to the donor. Adult OE contains progenitors responsible for the normal life-long continuous replacement of neurons and supporting cells. Culture techniques have been established for human OE that generate populations of mitotically active neural progenitors that form neurospheres (Roisen et al., 2001; Winstead et al., 2005). The potential application of this technology includes autologous transplantation where minimal donor material can be isolated, expanded ex vivo, and lineage restricted to a desired phenotype prior to/or after re-implantation. Furthermore, these strategies circumvent the ethical issues that arise with embryonic or fetal tissues. The long term goal is to develop procedures through which a victim of a spinal cord injury or neurodegenerative condition would serve as a source of progenitors for his/her own regenerative grafts, avoiding the need for immunosuppression and ethical controversy. In addition, these cells can provide populations for pharmacological and/or diagnostic evaluation.

  18. Progressive effects of N-myc deficiency on proliferation, neurogenesis, and morphogenesis in the olfactory epithelium.

    Science.gov (United States)

    Wittmann, Walter; Schimmang, Thomas; Gunhaga, Lena

    2014-06-01

    N-myc belongs to the myc proto-oncogene family, which is involved in numerous cellular processes such as proliferation, growth, apoptosis, and differentiation. Conditional deletion of N-myc in the mouse nervous system disrupted brain development, indicating that N-myc plays an essential role during neural development. How the development of the olfactory epithelium and neurogenesis within are affected by the loss of N-myc has, however, not been determined. To address these issues, we examined an N-myc(Foxg1Cre) conditional mouse line, in which N-myc is depleted in the olfactory epithelium. First changes in N-myc mutants were detected at E11.5, with reduced proliferation and neurogenesis in a slightly smaller olfactory epithelium. The phenotype was more pronounced at E13.5, with a complete lack of Hes5-positive progenitor cells, decreased proliferation, and neurogenesis. In addition, stereological analyses revealed reduced cell size of post-mitotic neurons in the olfactory epithelium, which contributed to a smaller olfactory pit. Furthermore, we observed diminished proliferation and neurogenesis also in the vomeronasal organ, which likewise was reduced in size. In addition, the generation of gonadotropin-releasing hormone neurons was severely reduced in N-myc mutants. Thus, diminished neurogenesis and proliferation in combination with smaller neurons might explain the morphological defects in the N-myc depleted olfactory structures. Moreover, our results suggest an important role for N-myc in regulating ongoing neurogenesis, in part by maintaining the Hes5-positive progenitor pool. In summary, our results provide evidence that N-myc deficiency in the olfactory epithelium progressively diminishes proliferation and neurogenesis with negative consequences at structural and cellular levels.

  19. Olfactory bulb encoding during learning under anesthesia

    Science.gov (United States)

    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

  20. Olfactory bulb encoding during learning under anaesthesia

    Directory of Open Access Journals (Sweden)

    Alister U Nicol

    2014-06-01

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

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. [Wilson's disease associated with olfactory paranoid syndrome and idiopathic thrombocytopenic purpura].

    Science.gov (United States)

    Sagawa, Morihiko; Takao, Masaki; Nogawa, Shigeru; Mizuno, Masafumi; Murata, Mitsuru; Amano, Takahiro; Koto, Atsuo

    2003-10-01

    In this study we report an individual of Wilson's disease associated with olfactory paranoid syndrome and idiopathic thrombocytopenic purpura. The initial symptom of this female patient was olfactory paranoia at age 17. Although that psychiatric symptom was well controlled under pharmacological treatment for two years, she developed olfactory paranoia as well as sialorrhea, dysarthria and finger tremor at age 20. A year later rigidity was also present in the extremities. At age 23, idiopathic thrombocytopenic purpura was found based on hematological examinations. Because her extrapyramidal symptoms were progressive, she was referred to our department to evaluate her neurologic condition. She was diagnosed as having Wilson's disease based on (1) the presence of Kayser-Fleischer rings, (2) extrapyramidal signs, and (3) a decreased level of serum copper and ceruloplasmin. T2 and FLAIR images of brain MRI showed hyperintense lesions in the putamen, thalamus and pontine tegmentum. Diffusion-weighted images also showed hyperintense lesions in the thalamus and pontine tegmentum. The biopsy specimen of the liver revealed chronic hepatitis with copper accumulation. Since D-penicillamine treatment was initiated, she has shown no olfactory paranoia and exacerbation of ITP. Her gait disturbance has also improved. Olfactory paranoia and ITP are rare clinical complications of Wilson's disease. Further analysis may warrant consideration of the pathophysiological mechanism of the psychiatric, hematological and neuroradiological condition seen in Wilson's disease.

  11. 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...... 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....

  12. 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.

  13. 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.

  14. 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.

  15. Sensory deprivation disrupts homeostatic regeneration of newly generated olfactory sensory neurons after injury in adult mice.

    Science.gov (United States)

    Kikuta, Shu; Sakamoto, Takashi; Nagayama, Shin; Kanaya, Kaori; Kinoshita, Makoto; Kondo, Kenji; Tsunoda, Koichi; Mori, Kensaku; Yamasoba, Tatsuya

    2015-02-11

    Although it is well known that injury induces the generation of a substantial number of new olfactory sensory neurons (OSNs) in the adult olfactory epithelium (OE), it is not well understood whether olfactory sensory input influences the survival and maturation of these injury-induced OSNs in adults. Here, we investigated whether olfactory sensory deprivation affected the dynamic incorporation of newly generated OSNs 3, 7, 14, and 28 d after injury in adult mice. Mice were unilaterally deprived of olfactory sensory input by inserting a silicone tube into their nostrils. Methimazole, an olfactotoxic drug, was also injected intraperitoneally to bilaterally ablate OSNs. The OE was restored to its preinjury condition with new OSNs by day 28. No significant differences in the numbers of olfactory marker protein-positive mature OSNs or apoptotic OSNs were observed between the deprived and nondeprived sides 0-7 d after injury. However, between days 7 and 28, the sensory-deprived side showed markedly fewer OSNs and mature OSNs, but more apoptotic OSNs, than the nondeprived side. Intrinsic functional imaging of the dorsal surface of the olfactory bulb at day 28 revealed that responses to odor stimulation were weaker in the deprived side compared with those in the nondeprived side. Furthermore, prevention of cell death in new neurons 7-14 d after injury promoted the recovery of the OE. These results indicate that, in the adult OE, sensory deprivation disrupts compensatory OSN regeneration after injury and that newly generated OSNs have a critical time window for sensory-input-dependent survival 7-14 d after injury.

  16. Olfactory bulb transplantation in complete spinal cord injury: axonal regeneration and locomotor recovery

    Directory of Open Access Journals (Sweden)

    Carlos Abraham Arellanes-Chávez

    2015-03-01

    Full Text Available OBJECTIVES: To determine whether the intervention in rats is effective in terms of spinal cord regeneration and locomotor recovery, in order to obtain sufficient evidence to apply the therapy in humans. METHODS: a randomized, controlled, experimental, prospective, randomized trial was conducted, with a sample of 15 adult female Sprague-Dawley rats weighing 250 gr. They were divided into three equal groups, and trained for 2 weeks based on Pavlov's classical conditioning method, to strengthen the muscles of the 4 legs, stimulate the rats mentally, and keep them healthy for the surgery. RESULTS: It was observed that implantation of these cells into the site of injury may be beneficial to the process of spinal cord regeneration after spinal trauma, to mediate secretion of neurotrophic and neuroprotective chemokines, and that the OECs have the ability to bridge the repair site and decrease the formation of gliosis, creating a favorable environment for axonal regeneration. CONCLUSION: It is emphasized that the olfactory ensheathing glial cells possess unique regenerative properties; however, it was not until recently that the activity of promoting central nervous system regeneration was recognized.

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

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2009-12-01

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

  18. 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.

  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. The effect of environmental temperature on olfactory perception in Drosophila melanogaster.

    Science.gov (United States)

    Riveron, Jacob; Boto, Tamara; Alcorta, Esther

    2009-10-01

    Olfaction provides chemical information to an animal about its environment. When environmental conditions change, individuals should be able to adequately maintain function. Temperature may influence olfaction in a double manner, as it modifies the concentrations of gaseous compounds and affects biological processes. Here, we address acclimatization to environmental temperature in the olfactory system of Drosophila melanogaster using heat and cold treatments. Because the consequences of temperature shifts persist for some time after the treatment's end, comparison of olfactory behaviors at the same temperature in treated and untreated flies allows us to infer the biological effects of temperature in olfaction. At intermediate odorant concentrations heat always generates a reduction of olfactory sensitivity, as they would be expected to compensate for the increase of volatiles in the air. Cold produces the opposite effect. These changes are observed in both sexes and in natural populations as well as in standard laboratory stocks. Short applications suffice to cause detectable olfactory perception changes, but even prolonged temperature treatments have only a transitory effect. Together, these results suggest that olfaction in Drosophila underlies acclimatization to environmental temperature. However, sensitivity changes are not immediate and may cause imperfect adjustment of olfactory function for short time periods.

  1. Cerebral Cortex Expression of Gli3 Is Required for Normal Development of the Lateral Olfactory Tract.

    Directory of Open Access Journals (Sweden)

    Eleni-Maria Amaniti

    Full Text Available Formation of the lateral olfactory tract (LOT and innervation of the piriform cortex represent fundamental steps to allow the transmission of olfactory information to the cerebral cortex. Several transcription factors, including the zinc finger transcription factor Gli3, influence LOT formation by controlling the development of mitral cells from which LOT axons emanate and/or by specifying the environment through which these axons navigate. Gli3 null and hypomorphic mutants display severe defects throughout the territory covered by the developing lateral olfactory tract, making it difficult to identify specific roles for Gli3 in its development. Here, we used Emx1Cre;Gli3fl/fl conditional mutants to investigate LOT formation and colonization of the olfactory cortex in embryos in which loss of Gli3 function is restricted to the dorsal telencephalon. These mutants form an olfactory bulb like structure which does not protrude from the telencephalic surface. Nevertheless, mitral cells are formed and their axons enter the piriform cortex though the LOT is shifted medially. Mitral axons also innervate a larger target area consistent with an enlargement of the piriform cortex and form aberrant projections into the deeper layers of the piriform cortex. No obvious differences were found in the expression patterns of key guidance cues. However, we found that an expansion of the piriform cortex temporally coincides with the arrival of LOT axons, suggesting that Gli3 affects LOT positioning and target area innervation through controlling the development of the piriform cortex.

  2. 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.

  3. Olfactory Performance Can Be Influenced by the Presentation Order, Background Noise, and Positive Concurrent Feedback.

    Science.gov (United States)

    Walliczek-Dworschak, Ute; Pellegrino, Robert; Lee, Shangwa; Hummel, Cornelia; Hähner, Antje; Hummel, Thomas

    2016-10-01

    Sniffin' Sticks have become a popular procedure to measure overall olfactory functionality with 3 subtest: phenyl ethyl alcohol threshold test (T), discrimination (D), and identification (I). However, several procedural components specified by the original paper have not been tested nor has the impact of deviations been measured. The aim of the present work was to measure olfactory performance under modified testing procedures. First, the reverse order of subtests (IDT) was compared with more standard practices (TDI). Next, the possible impact of background noise and positive concurrent feedback were assessed. A total of 120 individuals participated in the study where the 3 conditional experiments, each involving 40 participants, were completed. Testing procedures that reversed the presentation order of subtests (I->D->T) scored a significantly lower overall TDI score than standard testing order with the threshold subtest being the most influenced. Additionally, nonverbal background noise lowered overall olfactory performance while concurrent feedback modulated threshold performance. These results emphasize the importance of testing parameters where olfactory perception and tasks may be modulated by adaptation and attentional distraction, respectively. This study helped furthermore to demonstrate that the investigated 3 deviations from the standard procedure revealed a significant impact on the performance outcome in olfactory assessment using the Sniffin' Sticks.

  4. 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)

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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…

  10. Neural coding in antennal olfactory cells of tsetse flies (Glossina spp.)

    NARCIS (Netherlands)

    Voskamp, K.E; Noorman, N; Mastebroek, H.A K; van Schoot, N.E.G.; den Otter, C.J

    1998-01-01

    Spike trains from individual antennal olfactory cells of tsetse flies (Glossina spp.) obtained during steady-state conditions (spontaneous as well as during stimulation with 1-octen-3-ol) and dynamic stimulation with repetitive pulses of 1-octen-3-ol were investigated by studying the spike frequency

  11. 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…

  12. Intrinsic conductances actively shape excitatory and inhibitory postsynaptic responses in olfactory bulb external tufted cells.

    Science.gov (United States)

    Liu, Shaolin; Shipley, Michael T

    2008-10-08

    The initial synapse in the olfactory system is from olfactory nerve (ON) terminals to postsynaptic targets in olfactory bulb glomeruli. Recent studies have disclosed multiple presynaptic factors that regulate this important linkage, but less is known about the contribution of postsynaptic intrinsic conductances to integration at these synapses. The present study demonstrates voltage-dependent amplification of EPSPs in external tufted (ET) cells in response to monosynaptic (ON) inputs. This amplification is mainly exerted by persistent Na(+) conductance. Larger EPSPs, which bring the membrane potential to a relatively depolarized level, are further boosted by the low-voltage-activated Ca(2+) conductance. In contrast, the hyperpolarization-activated nonselective cation conductance (I(h)) attenuates EPSPs mainly by reducing EPSP duration; this also reduces temporal summation of multiple EPSPs. Regulation of EPSPs by these subthreshold, voltage-dependent conductances can enhance both the signal-to-noise ratio and the temporal summation of multiple synaptic inputs and thus help ET cells differentiate high- and low-frequency synaptic inputs. I(h) can also transform inhibitory inputs to postsynaptic excitation. When the ET cell membrane potential is relatively depolarized, as during a burst of action potentials, IPSPs produce classic inhibition. However, near resting membrane potentials where I(h) is engaged, IPSPs produce rebound bursts of action potentials. ET cells excite GABAergic PG cells. Thus, the transformation of inhibitory inputs to postsynaptic excitation in ET cells may enhance intraglomerular inhibition of mitral/tufted cells, the main output neurons in the olfactory bulb, and hence shape signaling to olfactory cortex.

  13. 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.

  14. Context-driven activation of odor representations in the absence of olfactory stimuli in the olfactory bulb and piriform cortex.

    Science.gov (United States)

    Mandairon, Nathalie; Kermen, Florence; Charpentier, Caroline; Sacquet, Joelle; Linster, Christiane; Didier, Anne

    2014-01-01

    Sensory neural activity is highly context dependent and shaped by experience and expectation. In the olfactory bulb (OB), the first cerebral relay of olfactory processing, responses to odorants are shaped by previous experiences including contextual information thanks to strong feedback connections. In the present experiment, mice were conditioned to associate an odorant with a visual context and were then exposed to the visual context alone. We found that the visual context alone elicited exploration of the odor port similar to that elicited by the stimulus when it was initially presented. In the OB, the visual context alone elicited a neural activation pattern, assessed by mapping the expression of the immediate early gene zif268 (egr-1) that was highly similar to that evoked by the conditioned odorant, but not other odorants. This OB activation was processed by olfactory network as it was transmitted to the piriform cortex. Interestingly, a novel context abolished neural and behavioral responses. In addition, the neural representation in response to the context was dependent on top-down inputs, suggesting that context-dependent representation is initiated in cortex. Modeling of the experimental data suggests that odor representations are stored in cortical networks, reactivated by the context and activate bulbar representations. Activation of the OB and the associated behavioral response in the absence of physical stimulus showed that mice are capable of internal representations of sensory stimuli. The similarity of activation patterns induced by imaged and the corresponding physical stimulus, triggered only by the relevant context provides evidence for an odor-specific internal representation.

  15. 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.

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

    Science.gov (United States)

    Takahashi, Lorey K

    2014-01-01

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

  17. Adult c-Kit(+) progenitor cells are necessary for maintenance and regeneration of olfactory neurons.

    Science.gov (United States)

    Goldstein, Bradley J; Goss, Garrett M; Hatzistergos, Konstantinos E; Rangel, Erika B; Seidler, Barbara; Saur, Dieter; Hare, Joshua M

    2015-01-01

    The olfactory epithelium houses chemosensory neurons, which transmit odor information from the nose to the brain. In adult mammals, the olfactory epithelium is a uniquely robust neuroproliferative zone, with the ability to replenish its neuronal and non-neuronal populations due to the presence of germinal basal cells. The stem and progenitor cells of these germinal layers, and their regulatory mechanisms, remain incompletely defined. Here we show that progenitor cells expressing c-Kit, a receptor tyrosine kinase marking stem cells in a variety of embryonic tissues, are required for maintenance of the adult neuroepithelium. Mouse genetic fate-mapping analyses show that embryonically, a c-Kit(+) population contributes to olfactory neurogenesis. In adults under conditions of normal turnover, there is relatively sparse c-Kit(+) progenitor cell (ckPC) activity. However, after experimentally induced neuroepithelial injury, ckPCs are activated such that they reconstitute the neuronal population. There are also occasional non-neuronal cells found to arise from ckPCs. Moreover, the selective depletion of the ckPC population, utilizing temporally controlled targeted diphtheria toxin A expression, results in failure of neurogenesis after experimental injury. Analysis of this model indicates that most ckPCs reside among the globose basal cell populations and act downstream of horizontal basal cells, which can serve as stem cells. Identification of the requirement for olfactory c-Kit-expressing progenitors in olfactory maintenance provides new insight into the mechanisms involved in adult olfactory neurogenesis. Additionally, we define an important and previously unrecognized site of adult c-Kit activity.

  18. 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.

  19. 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.

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

    Science.gov (United States)

    Mauelshagen, J

    1993-02-01

    1. Sensitization and classical odor conditioning of the proboscis extension reflex were functionally analyzed by repeated intracellular recordings from a single identified neuron (PE1-neuron) in the central bee brain. This neuron belongs to the class of "extrinsic cells" arising from the pedunculus of the mushroom bodies and has extensive arborizations in the median and lateral protocerebrum. The recordings were performed on isolated bee heads. 2. Two different series of physiological experiments were carried out with the use of a similar temporal succession of stimuli as in previous behavioral experiments. In the first series, one group of animals was used for a single conditioning trial [conditioned stimulus (CS), carnation; unconditioned stimulus (US), sucrose solution to the antennae and proboscis), a second group was used for sensitization (sensitizing stimulus, sucrose solution to the antennae and/or proboscis), and the third group served as control (no sucrose stimulation). In the second series, a differential conditioning paradigm (paired odor CS+, carnation; unpaired odor CS-, orange blossom) was applied to test the associative nature of the conditioning effect. 3. The PE1-neuron showed a characteristic burstlike odor response before the training procedures. The treatments resulted in different spike-frequency modulations of this response, which were specific for the nonassociative and associative stimulus paradigms applied. During differential conditioning, there are dynamic up and down modulations of spike frequencies and of the DC potentials underlying the responses to the CS+. Overall, only transient changes in the minute range were observed. 4. The results of the sensitization procedures suggest two qualitatively different US pathways. The comparison between sensitization and one-trial conditioning shows differential effects of nonassociative and associative stimulus paradigms on the response behavior of the PE1-neuron. The results of the differential

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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…

  8. 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.

  9. 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.

  10. Olfactory-visual congruence effects stable across ages: yellow is warmer when it is pleasantly lemony.

    Science.gov (United States)

    Guerdoux, Estelle; Trouillet, Raphaël; Brouillet, Denis

    2014-07-01

    This study aimed to examine the age-related differences in the olfactory-visual cross-correspondences and the extent to which they are moderated by the odors pleasantness. Sixty participants aged from 20- to 75- years (young, middle-aged and older adults) performed a priming task to explore the influence of six olfactory primes (lemon, orange, rose, thyme, mint and fish) on the categorization (cool vs. warm) of six subsequent color targets (yellow, orange, pink, malachite green, grass-green, and blue-gray). We tested mixed effects models. Response times were regressed on covariates models using both fixed effects (Groups of age, olfactory Pleasantness and multimodal Condition) and cross-random effects (Subject, Color and Odor). The random effects coding for Odor (p < .001) and Color (p = .001) were significant. There was a significant interaction effect ( p= .004) between Condition × Pleasantness, but not with Groups of age. The compatibility effect (i.e., when odors and colors were congruent, the targets processing were facilitated) was as much enhanced as the olfactory primes were pleasant. Cross-correspondences between olfaction and vision may be robust in aging. They should be considered alongside spatiotemporal but also emotional congruency.

  11. Mechanics classical and quantum

    CERN Document Server

    Taylor, T T

    2015-01-01

    Mechanics: Classical and Quantum explains the principles of quantum mechanics via the medium of analytical mechanics. The book describes Schrodinger's formulation, the Hamilton-Jacobi equation, and the Lagrangian formulation. The author discusses the Harmonic Oscillator, the generalized coordinates, velocities, as well as the application of the Lagrangian formulation to systems that are partially or entirely electromagnetic in character under certain conditions. The book examines waves on a string under tension, the isothermal cavity radiation, and the Rayleigh-Jeans result pertaining to the e

  12. Salivary conditioning with antennal gustatory unconditioned stimulus in an insect.

    Science.gov (United States)

    Watanabe, Hidehiro; Sato, Chihiro; Kuramochi, Tomokazu; Nishino, Hiroshi; Mizunami, Makoto

    2008-07-01

    Classical conditioning of olfactory conditioning stimulus (CS) with gustatory unconditioned stimulus (US) in insects has been used as a pertinent model for elucidation of neural mechanisms underlying learning and memory. However, a conditioning system in which stable intracellular recordings from brain neurons are feasibly obtained while monitoring the conditioning effect has remained to be established. Recently, we found classical conditioning of salivation in cockroaches Periplaneta americana, in which an odor was associated with sucrose solution applied to the mouth, and this conditioning could be monitored by activities of salivary neurons. Application of gustatory US to the mouth, however, leads to feeding movement accompanying a movement of the brain that prevents stable recordings from brain neurons. Here we investigated whether a gustatory stimulus presented to an antenna could serve as an effective US for producing salivary conditioning. Presentation of sucrose or sodium chloride solution to an antenna induced salivation and also increased activities of salivary neurons. A single pairing trial of an odor with antennal presentation of sucrose or sodium chloride solution produced conditioning of salivation or of activities of salivary neurons. Five pairing trials led to a conditioning effect that lasted for one day. Water or tactile stimulus presented to an antenna was not effective for producing conditioning. The results demonstrate that gustatory US presented to an antenna is as effective as that presented to the mouth for producing salivary conditioning. This conditioning system provides a useful model for studying the neural basis of learning at the level of singly identifiable neurons.

  13. 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.

  14. 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

  15. The involvement of ventral tegmental area cholinergic muscarinic receptors in classically conditioned fear expression as measured with fear-potentiated startle.

    Science.gov (United States)

    Greba, Q; Munro, L J; Kokkinidis, L

    2000-07-01

    Accumulating evidence suggests that dopamine (DA) neurons in the ventral tegmental area (VTA) contribute to the complex amygdala-based neurocircuitry that mediates fear-motivated behaviors. Because of acetylcholine's (ACh) role in DA neuronal activation, the involvement of VTA cholinergic muscarinic receptors in Pavlovian conditioned fear responding was evaluated in the present study. Fear-potentiated startle was used to assess the effects of intraVTA infused methylscopolamine on conditioned fear performance in laboratory rats. Application of this nonspecific muscarinic receptor antagonist to VTA neurons was observed to inhibit the ability of a conditioned stimulus (CS) previously paired with footshock to enhance the amplitude of the acoustic startle reflex. Doses of methylscopolamine that blocked conditioned fear expression did not alter baseline sensorimotor responding. These results identify ACh neurotransmission in the VTA as a potential excitatory mechanism underlying the fear-arousing properties of threatening environmental stimuli.

  16. Olfactory sensitivity and odor structure-activity relationships for aliphatic carboxylic acids in CD-1 mice.

    Science.gov (United States)

    Can Güven, Selçuk; Laska, Matthias

    2012-01-01

    Using a conditioning paradigm, the olfactory sensitivity of CD-1 mice for a homologous series of aliphatic n-carboxylic acids (ethanoic acid to n-octanoic acid) and several of their isomeric forms was investigated. With all 14 odorants, the animals significantly discriminated concentrations as low as 0.03 ppm (parts per million) from the solvent, and with four odorants the best-scoring animals even detected concentrations as low as 3 ppt (parts per trillion). Analysis of odor structure-activity relationships showed that the correlation between olfactory detection thresholds of the mice for the unbranched carboxylic acids and carbon chain length can best be described as a U-shaped function with the lowest threshold values at n-butanoic acid. A significant positive correlation between olfactory detection thresholds and carbon chain length of the carboxylic acids with their branching next to the functional carboxyl group was found. In contrast, no such correlation was found for carboxylic acids with their branching at the distal end of the carbon chain relative to the functional carboxyl group. Finally, a significant correlation was found between olfactory detection thresholds and the position of the branching of the carboxylic acids. Across-species comparisons suggest that mice are more sensitive for short-chained (C(2) to C(4)) aliphatic n-carboxylic acids than other mammalian species, but not for longer-chained ones (C(5) to C(8)). Further comparisons suggest that odor structure-activity relationships are both substance class- and species-specific.

  17. Recovery of olfactory function after nine years of post-traumatic anosmia: a case report

    Directory of Open Access Journals (Sweden)

    Mueller Christian A

    2009-09-01

    Full Text Available Abstract Introduction Olfactory loss due to head trauma is a common condition. Depending on the severity of the head trauma, anosmia might occur in up to 30% of patients. The period of time until recovery has been reported to be a couple of months in most cases. However, recovery from post-traumatic olfactory loss might occur much later. We present a rare case of recovery from anosmia nine years after the initial trauma. Case presentation We report the case of a 54-year-old Caucasian man who suffered complete anosmia from a severe car accident. Smell function as well as flavor perception during eating and drinking were also completely lost. After nine years, the patient had his first olfactory impressions, with his sense of smell gradually improving over a period of three years. We confirmed recovery of olfactory function using psychophysical and electrophysiological techniques. Conclusion In most cases, recovery of smell function occurs relatively soon after the head trauma and seems to rarely occur more than two years after the incident. However, patients should be informed that there is a small chance of recovery a long time after the trauma.

  18. What classicality? Decoherence and Bohr's classical concepts

    CERN Document Server

    Schlosshauer, Maximilian

    2010-01-01

    Niels Bohr famously insisted on the indispensability of what he termed "classical concepts." In the context of the decoherence program, on the other hand, it has become fashionable to talk about the "dynamical emergence of classicality" from the quantum formalism alone. Does this mean that decoherence challenges Bohr's dictum and signifies a break with the Copenhagen interpretation-for example, that classical concepts do not need to be assumed but can be derived? In this paper we'll try to shine some light down the murky waters where formalism and philosophy cohabitate. To begin, we'll clarify the notion of classicality in the decoherence description. We'll then discuss Bohr's and Heisenberg's take on the quantum-classical problem and reflect on different meanings of the terms "classicality" and "classical concepts" in the writings of Bohr and his followers. This analysis will allow us to put forward some tentative suggestions for how we may better understand the relation between decoherence-induced classical...

  19. 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.

  20. 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.

  1. Effects of OEF/OIF-related physical and emotional co-morbidities on associative learning: concurrent delay and trace eyeblink classical conditioning.

    Science.gov (United States)

    McGlinchey, Regina E; Fortier, Catherine B; Venne, Jonathan R; Maksimovskiy, Arkadiy L; Milberg, William P

    2014-03-12

    This study examined the performance of veterans and active duty personnel who served in Operation Enduring Freedom and/or Operation Iraqi Freedom (OEF/OIF) on a basic associative learning task. Eighty-eight individuals participated in this study. All received a comprehensive clinical evaluation to determine the presence and severity of posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI). The eyeblink conditioning task was composed of randomly intermixed delay and trace conditioned stimulus (CS) and unconditioned stimulus (US) pairs (acquisition) followed by a series of CS only trials (extinction). Results revealed that those with a clinical diagnosis of PTSD or a diagnosis of PTSD with comorbid mTBI acquired delay and trace conditioned responses (CRs) to levels and at rates similar to a deployed control group, thus suggesting intact basic associative learning. Differential extinction impairment was observed in the two clinical groups. Acquisition of CRs for both delay and trace conditioning, as well as extinction of trace CRs, was associated with alcoholic behavior across all participants. These findings help characterize the learning and memory function of individuals with PTSD and mTBI from OEF/OIF and raise the alarming possibility that the use of alcohol in this group may lead to more significant cognitive dysfunction.

  2. Effects of OEF/OIF-Related Physical and Emotional Co-Morbidities on Associative Learning: Concurrent Delay and Trace Eyeblink Classical Conditioning

    Directory of Open Access Journals (Sweden)

    Regina E. McGlinchey

    2014-03-01

    Full Text Available This study examined the performance of veterans and active duty personnel who served in Operation Enduring Freedom and/or Operation Iraqi Freedom (OEF/OIF on a basic associative learning task. Eighty-eight individuals participated in this study. All received a comprehensive clinical evaluation to determine the presence and severity of posttraumatic stress disorder (PTSD and traumatic brain injury (TBI. The eyeblink conditioning task was composed of randomly intermixed delay and trace conditioned stimulus (CS and unconditioned stimulus (US pairs (acquisition followed by a series of CS only trials (extinction. Results revealed that those with a clinical diagnosis of PTSD or a diagnosis of PTSD with comorbid mTBI acquired delay and trace conditioned responses (CRs to levels and at rates similar to a deployed control group, thus suggesting intact basic associative learning. Differential extinction impairment was observed in the two clinical groups. Acquisition of CRs for both delay and trace conditioning, as well as extinction of trace CRs, was associated with alcoholic behavior across all participants. These findings help characterize the learning and memory function of individuals with PTSD and mTBI from OEF/OIF and raise the alarming possibility that the use of alcohol in this group may lead to more significant cognitive dysfunction.

  3. File list: Unc.Oth.05.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

  6. File list: Unc.Oth.10.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Oth.10.AllAg.Olfactory_epithelium mm9 Unclassified Others Olfactory epithelium ...SRX112960 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.10.AllAg.Olfactory_epithelium.bed ...

  7. Neurogenesis in the adult olfactory bulb

    Institute of Scientific and Technical Information of China (English)

    Angela Pignatelli; Cristina Gambardella; Ottorino Belluzzi

    2011-01-01

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

  8. 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

  9. 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.

  10. 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...

  11. 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.)

  12. The banana code – Natural blend processing in the olfactory circuitry of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Marco eSchubert

    2014-02-01

    Full Text Available Odor information is predominantly perceived as complex odor blends. For Drosophila melanogaster one of the most attractive blends is emitted by an over-ripe banana. To analyze how the fly’s olfactory system processes natural blends we combined the experimental advantages of gas chromatography and functional imaging (GC-I. In this way, natural banana compounds were presented successively to the fly antenna in close to natural occurring concentrations. This technique allowed us to identify the active odor components, use these compounds as stimuli and measure odor-induced Ca2+ signals in input and output neurons of the Drosophila antennal lobe (AL, the first olfactory neuropil. We demonstrate that mixture interactions of a natural blend are very rare and occur only at the AL output level resulting in a surprisingly linear blend representation. However, the information regarding single components is strongly modulated by the olfactory circuitry within the AL leading to a higher similarity between the representation of individual components and the banana blend. This observed modulation might tune the olfactory system in a way to distinctively categorize odor components and improve the detection of suitable food sources. Functional GC-I thus enables analysis of virtually any unknown natural odorant blend and its components in their relative occurring concentrations and allows characterization of neuronal responses of complete neural assemblies. This technique can be seen as a valuable complementary method to classical GC/electrophysiology techniques, and will be a highly useful tool in future investigations of insect-insect and insect-plant chemical interactions.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Overview of Classical Swine Fever (Hog Cholera, Classical Swine fever)

    Science.gov (United States)

    Classical swine fever is a contagious often fatal disease of pigs clinically characterized by high body temperature, lethargy, yellowish diarrhea, vomits and purple skin discoloration of ears, lower abdomen and legs. It was first described in the early 19th century in the USA. Later, a condition i...

  18. 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...

  19. Olfactory Sensitivity for Six Predator Odorants in CD-1 Mice, Human Subjects, and Spider Monkeys

    Science.gov (United States)

    Sarrafchi, Amir; Odhammer, Anna M. E.; Hernandez Salazar, Laura Teresa; Laska, Matthias

    2013-01-01

    Using a conditioning paradigm, we assessed the olfactory sensitivity of six CD-1 mice (Mus musculus) for six sulfur-containing odorants known to be components of the odors of natural predators of the mouse. With all six odorants, the mice discriminated concentrations <0.1 ppm (parts per million) from the solvent, and with five of the six odorants the best-scoring animals were even able to detect concentrations <1 ppt (parts per trillion). Four female spider monkeys (Ateles geoffroyi) and twelve human subjects (Homo sapiens) tested in parallel were found to detect the same six odorants at concentrations <0.01 ppm, and with four of the six odorants the best-scoring animals and subjects even detected concentrations <10 ppt. With all three species, the threshold values obtained here are generally lower than (or in the lower range of) those reported for other chemical classes tested previously, suggesting that sulfur-containing odorants may play a special role in olfaction. Across-species comparisons showed that the mice were significantly more sensitive than the human subjects and the spider monkeys with four of the six predator odorants. However, the human subjects were significantly more sensitive than the mice with the remaining two odorants. Human subjects and spider monkeys significantly differed in their sensitivity with only two of the six odorants. These comparisons lend further support to the notion that the number of functional olfactory receptor genes or the relative or absolute size of the olfactory bulbs are poor predictors of a species’ olfactory sensitivity. Analysis of odor structure–activity relationships showed that in both mice and human subjects the type of alkyl rest attached to a thietane and the type of oxygen moiety attached to a thiol significantly affected olfactory sensitivity. PMID:24278296

  20. Mesenchymal stem cells from rat olfactory bulbs can differentiate into cells with cardiomyocyte characteristics.

    Science.gov (United States)

    Huang, Yuahn-Sieh; Li, I-Hsun; Chueh, Sheau-Huei; Hueng, Dueng-Yuan; Tai, Ming-Cheng; Liang, Chang-Min; Lien, Shiu-Bii; Sytwu, Huey-Kang; Ma, Kuo-Hsing

    2015-12-01

    Mesenchymal stromal/stem cells (MSCs) are widely distributed in different tissues such as bone marrow, adipose tissues, peripheral blood, umbilical cord and amnionic fluid. Recently, MSC-like cells were also found to exist in rat olfactory bulb and are capable of inducing differentiation into mesenchymal lineages - osteocytes, chondrocytes and adipocytes. However, whether these cells can differentiate into myocardial cells is not known. In this study, we examined whether olfactory bulb-derived MSCs could differentiate into myocardial cells in vitro. Fibroblast-like cells isolated from the olfactory bulb of neonatal rats were grown under four conditions: no treatment; in the presence of growth factors (neuregulin-1, bFGF and forskolin); co-cultured with cardiomyocytes; and co-cultured with cardiomyocytes plus neuregulin-1, bFGF and forskolin. Cell differentiation into myocardial cells was monitored by RT-PCR, light microscopy immunofluorescence, western blot analysis and contractile response to pharmacological treatments. The isolated olfactory bulb-derived fibroblast-like cells expressed CD29, CD44, CD90, CD105, CD166 but not CD34 and CD45, consistent with the characteristics of MSCs. Long cylindical cells that spontaneously contracted were only observed following 7 days of co-culture of MSCs with rat cardiomyocytes plus neuregulin-1, bFGF and forskolin. RT-PCR and western blot analysis indicated that the cylindrical cells expressed myocardial markers, such as Nkx2.5, GATA4, sarcomeric α-actinin, cardiac troponin I, cardiac myosin heavy chain, atrial natriuretic peptide and connexin 43. They also contained sarcomeres and gap junction and were sensitive to pharmacological treatments (adrenal and cholinergic agonists and antagonists). These findings indicate that rat olfactory bulb-derived fibroblast-like cells with MSC characteristics can differentiate into myocardial-like cells.

  1. Olfactory and erectile dysfunction association in smoking and non-smoking men.

    Science.gov (United States)

    Özmen, Süay; Dülger, Seyhan; Çoban, Soner; Özmen, Ömer Afşın; Güzelsoy, Muhammed; Dikiş, Özlem Şengören; Akdeniz, Önder

    2016-06-01

    The studies evaluating the effect of smoking on olfaction reveals opposite results. In vitro and animal studies and epidemiological evidence from volunteers and patients, demonstrated the association between olfaction and erectile functions. In smoking man the reduction of olfactory acuity could adversely affect sexuality. The aim of the present study was to investigate the relationship between erectile dysfunction (ED) and olfactory dysfunction (OD) by comparing a group of healthy adult men with a group of smoking adult men. This prospective study involved 62 volunteers, who were recruited and divided into two groups; one consisted of 35 smoking adult men, and the other included 27 healthy non-smoking men. All participants in both groups were examined in detail for any condition with the potential to cause OD. They all had a normal genitourinary system suffered from no circulatory diseases, diabetes mellitus, hypertension, coronary artery disease nor hyperlipidemia; they had no history of medication affecting genitourinary system. Butanol threshold test and sniffin' stick® (Burghart, Wedel; Germany) screening test was used to asses olfactory functions in both groups. Participants' sexual desire was assessed using an International Index of Erectile Function (IIEF-5) scale. The means of sniffin' sticks scores, butanol threshold scores and IIEF-5 scores were statistically higher in non-smoking group. Butanol threshold scores and sniffin' sticks scores are correlated statistically with IIEF-5 in non-smoking and smoking groups. This study found an association between olfaction and erectile function in smoking and non-smoking men. As far as we know this study is the third published study to show the relationship olfactory and erectile function. In the future studies electrophysiological olfactory methods could be used to confirm in large cohorts the results obtained by the psychophysical approach.

  2. 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.

  3. Swiss identity smells like chocolate: Social identity shapes olfactory judgments.

    Science.gov (United States)

    Coppin, Géraldine; Pool, Eva; Delplanque, Sylvain; Oud, Bastiaan; Margot, Christian; Sander, David; Van Bavel, Jay J

    2016-10-11

    There is extensive evidence that social identities can shape people's attitudes and behavior, but what about sensory judgments? We examined the possibility that social identity concerns may also shape the judgment of non-social properties-namely, olfactory judgment. In two experiments, we presented Swiss and non-Swiss participants with the odor of chocolate, for which Switzerland is world-famous, and a control odor (popcorn). Swiss participants primed with Swiss identity reported the odor of chocolate (but not popcorn) as more intense than non-Swiss participants (Experiments 1 and 2) and than Swiss participants primed with individual identity or not primed (Experiment 2). The self-reported intensity of chocolate smell tended to increase as identity accessibility increased-but only among Swiss participants (Experiment 1). These results suggest that identity priming can counter-act classic sensory habituation effects, allowing identity-relevant smells to maintain their intensity after repeated presentations. This suggests that social identity dynamically influences sensory judgment. We discuss the potential implications for models of social identity and chemosensory perception.

  4. Classical and quantum Coulomb crystals

    CERN Document Server

    Bonitz, M; Baumgartner, H; Henning, C; Filinov, A; Block, D; Arp, O; Piel, A; Kading, S; Ivanov, Y; Melzer, A; Fehske, H; Filinov, V

    2008-01-01

    Strong correlation effects in classical and quantum plasmas are discussed. In particular, Coulomb (Wigner) crystallization phenomena are reviewed focusing on one-component non-neutral plasmas in traps and on macroscopic two-component neutral plasmas. The conditions for crystal formation in terms of critical values of the coupling parameters and the distance fluctuations and the phase diagram of Coulomb crystals are discussed.

  5. Classical mechanics without determinism

    OpenAIRE

    Nikolic, H.

    2005-01-01

    Classical statistical particle mechanics in the configuration space can be represented by a nonlinear Schrodinger equation. Even without assuming the existence of deterministic particle trajectories, the resulting quantum-like statistical interpretation is sufficient to predict all measurable results of classical mechanics. In the classical case, the wave function that satisfies a linear equation is positive, which is the main source of the fundamental difference between classical and quantum...

  6. Quantum computing classical physics.

    Science.gov (United States)

    Meyer, David A

    2002-03-15

    In the past decade, quantum algorithms have been found which outperform the best classical solutions known for certain classical problems as well as the best classical methods known for simulation of certain quantum systems. This suggests that they may also speed up the simulation of some classical systems. I describe one class of discrete quantum algorithms which do so--quantum lattice-gas automata--and show how to implement them efficiently on standard quantum computers.

  7. Exotic models may offer unique opportunities to decipher specific scientific question: the case of Xenopus olfactory system.

    Science.gov (United States)

    Gascuel, Jean; Amano, Tosikazu

    2013-09-01

    The fact that olfactory systems are highly conserved in all animal species from insects to mammals allow the generalization of findings from one species to another. Most of our knowledge about the anatomy and physiology of the olfactory system comes from data obtained in a very limited number of biological models such as rodents, Zebrafish, Drosophila, and a worm, Caenorhabditis elegans. These models have proved useful to answer most questions in the field of olfaction, and thus concentrating on these few models appear to be a pragmatic strategy. However, the diversity of the organization and physiology of the olfactory system amongst phyla appear to be greater than generally assumed and the four models alone may not be sufficient to address all the questions arising from the study of olfaction. In this article, we will illustrate the idea that we should take advantage of biological diversity to address specific scientific questions and will show that the Xenopus olfactory system is a very good model to investigate: first, olfaction in aerial versus aquatic conditions and second, mechanisms underlying postnatal reorganization of the olfactory system especially those controlled by tyroxine hormone.

  8. 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.

  9. 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....

  10. Comparison research of the classical eyeblink conditioning in guinea pig induced by visual and auditory circle%视觉与听觉通路诱导的豚鼠眨眼条件反射的比较研究

    Institute of Scientific and Technical Information of China (English)

    范郑丽; 隋建峰; 李蕊; 万子兵; 赵红梅

    2009-01-01

    目的 以眼肌电记录法分别记录豚鼠以声音和光信号作为条件刺激(CS)的眨眼条件反射(CR),分析并比较其习得规律.方法 采用金属电极埋植技术及简易"随动"气流给气刺激装置,分别以声音和光信号作为条件刺激(CS),以气流作为非条件刺激(US),以眼肌电信号判断其眨眼行为,在清醒无制动的豚鼠上进行经典眨眼条件反射的训练.结果 在豚鼠内眦采集并记录到眨眼肌电信号显示,声音条件刺激组在第1天、第4天、第7天、第10天的CR习得率分别为(5.0±1.09)%、(31.0±2.09)%、(61.33±1.63)%、(82.33±1.63)%,而光条件刺激组在第1天、第4天、第7天、第10天的CR习得率分别为(5.5±4.59)%、(4.33±3.14)%、(10.83±13.42)%、(3.83±1.33)%,2组CR习得率差异有显著性(P<0.05).结论 以声音作为条件刺激时豚鼠能够成功建立的眨眼条件反射,而以光作为条件刺激时眨眼条件反射的建立却非常困难.%Objective To record the classical eyeblink conditioning single,which the conditioned stimu-lus(CS) is tone or light, by the electromyographic (EMG) of musculi oculi recording. Methods Adopting metal electrode embedding technic and simple air puff stimulus facility ,tone or light as the conditioned stimulus(CS) was paired with air puff being unconditioned stimulus(US) to establish classical eyeblink conditioning of conscious un-fixed guinea pigs. The eyeblink behavior were evaluated through EMG of musculi oculi. Results The eyeblink EMG signal of musculi oculi showed: when the tone as the CS , the results indicated that the acquisition rate of the 1st,the 4th,the 7th,the 10th day were respectively (5.0±1.09)%,(31.0±2.09)%,(61.33±1.63)%,(82.33±1.63) % ; when the light as the CS , the results indicate that the acquisition rate of the 1 st, the 4th, the 7th, the 10th day were respectively (5.5±4.59) %, (4.33±3.14) %, (10.83±13.42)%, (3.83±1.33 ) %. Conclu-sion While CS is tone,classical eyeblink

  11. Comparing classical and quantum equilibration

    CERN Document Server

    Malabarba, Artur S L; Short, Anthony J

    2016-01-01

    By using a physically-relevant and theory independent definition of measurement-based equilibration, we show quantitatively that equilibration is easier for quantum systems than for classical systems, in the situation where the initial state of the system is completely known (pure state). This shows that quantum equilibration is a fundamental, nigh unavoidable, aspect of physical systems, while classical equilibration relies on experimental ignorance. When the state is not completely known, a mixed state, this framework also shows quantum equilibration requires weaker conditions.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. Entanglement in Classical Optics

    CERN Document Server

    Ghose, Partha

    2013-01-01

    The emerging field of entanglement or nonseparability in classical optics is reviewed, and its similarities with and differences from quantum entanglement clearly pointed out through a recapitulation of Hilbert spaces in general, the special restrictions on Hilbert spaces imposed in quantum mechanics and the role of Hilbert spaces in classical polarization optics. The production of Bell-like states in classical polarization optics is discussed, and new theorems are proved to discriminate between separable and nonseparable states in classical wave optics where no discreteness is involved. The influence of the Pancharatnam phase on a classical Bell-like state is deived. Finally, to what extent classical polarization optics can be used to simulate quantum information processing tasks is also discussed. This should be of great practical importance because coherence and entanglement are robust in classical optics but not in quantum systems.

  18. 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.

  19. 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.

  20. 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 ...

  1. 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

  2. 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.

  3. 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.

  4. conditions

    Directory of Open Access Journals (Sweden)

    M. Venkatesulu

    1996-01-01

    Full Text Available Solutions of initial value problems associated with a pair of ordinary differential systems (L1,L2 defined on two adjacent intervals I1 and I2 and satisfying certain interface-spatial conditions at the common end (interface point are studied.

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

    Science.gov (United States)

    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…

  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. 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.

  8. 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.

  9. 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.

  10. 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

  11. Olfactory ensheathing glia are required for embryonic olfactory axon targeting and the migration of gonadotropin-releasing hormone neurons

    Directory of Open Access Journals (Sweden)

    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.

  12. Extended symmetrical classical electrodynamics.

    Science.gov (United States)

    Fedorov, A V; Kalashnikov, E G

    2008-03-01

    In this paper, we discuss a modification of classical electrodynamics in which "ordinary" point charges are absent. The modified equations contain additional terms describing the induced charges and currents. The densities of the induced charges and currents depend on the vector k and the vectors of the electromagnetic field, E and B . It is shown that the vectors E and B can be defined in terms of two four-potentials and the components of k are the components of a four-tensor of the third rank. The Lagrangian of the modified electrodynamics is defined. The conditions are derived at which only one four-potential determines the behavior of the electromagnetic field. It is also shown that static modified electrodynamics can describe the electromagnetic field in the inner region of an electric monopole. In the outer region of the electric monopole the electric field is governed by the Maxwell equations. It follows from boundary conditions at the interface between the inner and outer regions of the monopole that the vector k has a discrete spectrum. The electric and magnetic fields, energy, and angular momentum of the monopole are found for different eigenvalues of k .

  13. Classical, Semi-classical and Quantum Noise

    CERN Document Server

    Poor, H; Scully, Marlan

    2012-01-01

    David Middleton was a towering figure of 20th Century engineering and science and one of the founders of statistical communication theory. During the second World War, the young David Middleton, working with Van Fleck, devised the notion of the matched filter, which is the most basic method used for detecting signals in noise. Over the intervening six decades, the contributions of Middleton have become classics. This collection of essays by leading scientists, engineers and colleagues of David are in his honor and reflect the wide  influence that he has had on many fields. Also included is the introduction by Middleton to his forthcoming book, which gives a wonderful view of the field of communication, its history and his own views on the field that he developed over the past 60 years. Focusing on classical noise modeling and applications, Classical, Semi-Classical and Quantum Noise includes coverage of statistical communication theory, non-stationary noise, molecular footprints, noise suppression, Quantum e...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. mSWI/SNF (BAF) Complexes Are Indispensable for the Neurogenesis and Development of Embryonic Olfactory Epithelium.

    Science.gov (United States)

    Bachmann, Christina; Nguyen, Huong; Rosenbusch, Joachim; Pham, Linh; Rabe, Tamara; Patwa, Megha; Sokpor, Godwin; Seong, Rho H; Ashery-Padan, Ruth; Mansouri, Ahmed; Stoykova, Anastassia; Staiger, Jochen F; Tuoc, Tran

    2016-09-01

    Neurogenesis is a key developmental event through which neurons are generated from neural stem/progenitor cells. Chromatin remodeling BAF (mSWI/SNF) complexes have been reported to play essential roles in the neurogenesis of the central nervous system. However, whether BAF complexes are required for neuron generation in the olfactory system is unknown. Here, we identified onscBAF and ornBAF complexes, which are specifically present in olfactory neural stem cells (oNSCs) and olfactory receptor neurons (ORNs), respectively. We demonstrated that BAF155 subunit is highly expressed in both oNSCs and ORNs, whereas high expression of BAF170 subunit is observed only in ORNs. We report that conditional deletion of BAF155, a core subunit in both onscBAF and ornBAF complexes, causes impaired proliferation of oNSCs as well as defective maturation and axonogenesis of ORNs in the developing olfactory epithelium (OE), while the high expression of BAF170 is important for maturation of ORNs. Interestingly, in the absence of BAF complexes in BAF155/BAF170 double-conditional knockout mice (dcKO), OE is not specified. Mechanistically, BAF complex is required for normal activation of Pax6-dependent transcriptional activity in stem cells/progenitors of the OE. Our findings unveil a novel mechanism mediated by the mSWI/SNF complex in OE neurogenesis and development.

  20. 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.

  1. Lectures on Classical Integrability

    CERN Document Server

    Torrielli, Alessandro

    2016-01-01

    We review some essential aspects of classically integrable systems. The detailed outline of the lectures consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schroedinger model, principal chiral field); 4. Features of classical r-matrices: Belavin-Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel'fand-Levitan-Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  2. 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.

  3. 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.

  4. 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.

  5. Genetic dissection of pheromone processing reveals main olfactory system-mediated social behaviors in mice.

    Science.gov (United States)

    Matsuo, Tomohiko; Hattori, Tatsuya; Asaba, Akari; Inoue, Naokazu; Kanomata, Nobuhiro; Kikusui, Takefumi; Kobayakawa, Reiko; Kobayakawa, Ko

    2015-01-20

    Most mammals have two major olfactory subsystems: the main olfactory system (MOS) and vomeronasal system (VNS). It is now widely accepted that the range of pheromones that control social behaviors are processed by both the VNS and the MOS. However, the functional contributions of each subsystem in social behavior remain unclear. To genetically dissociate the MOS and VNS functions, we established two conditional knockout mouse lines that led to either loss-of-function in the entire MOS or in the dorsal MOS. Mice with whole-MOS loss-of-function displayed severe defects in active sniffing and poor survival through the neonatal period. In contrast, when loss-of-function was confined to the dorsal MOB, sniffing behavior, pheromone recognition, and VNS activity were maintained. However, defects in a wide spectrum of social behaviors were observed: attraction to female urine and the accompanying ultrasonic vocalizations, chemoinvestigatory preference, aggression, maternal behaviors, and risk-assessment behaviors in response to an alarm pheromone. Functional dissociation of pheromone detection and pheromonal induction of behaviors showed the anterior olfactory nucleus (AON)-regulated social behaviors downstream from the MOS. Lesion analysis and neural activation mapping showed pheromonal activation in multiple amygdaloid and hypothalamic nuclei, important regions for the expression of social behavior, was dependent on MOS and AON functions. Identification of the MOS-AON-mediated pheromone pathway may provide insights into pheromone signaling in animals that do not possess a functional VNS, including humans.

  6. Olfactory sensor processing in neural networks: lessons from modeling the fruit fly antennal lobe

    Directory of Open Access Journals (Sweden)

    J. Henning Proske

    2012-02-01

    Full Text Available The insect olfactory system can be a model for artificial olfactory devices. In particular, Drosophila melanogaster due to its genetic tractability has yielded much information about the design and function of such systems in biology. In this study we investigate possible network topologies to separate representations of odors in the primary olfactory neuropil, the antennal lobe. In particular we compare networks based on stochastic and homogeneous connection weight distributions to connectivities that are based on the input correlations between the glomeruli in the antennal lobe. We show that moderate homogeneous inhibition implements a soft winner-take-all mechanism when paired with realistic input from a database of odor responses in receptor cells. The sparseness of representations increases with stronger inhibition. Excitation, on the other hand, pushes the representation of odors closer together thus making them harder to distinguish. We further analyze the relationship between different inhibitory network topologies and the properties of the receptor responses to different odors. We show that realistic input from the database has a relatively high entropy of activation values over all odors and receptors compared to the theoretical maximum. Furthermore, under conditions in which the information in the input is artificially decreased, networks with heterogeneous topologies based on the similarity of glomerular response profiles perform best. These results indicate that in order to arrive at the most beneficial representation for odor discrimination it is important to finely tune the strength of inhibition in combination with taking into account the properties of the available sensors.

  7. 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.

  8. 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.

  9. 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.

  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. 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...

  12. Fermions from classical statistics

    OpenAIRE

    2010-01-01

    We describe fermions in terms of a classical statistical ensemble. The states $\\tau$ of this ensemble are characterized by a sequence of values one or zero or a corresponding set of two-level observables. Every classical probability distribution can be associated to a quantum state for fermions. If the time evolution of the classical probabilities $p_\\tau$ amounts to a rotation of the wave function $q_\\tau(t)=\\pm \\sqrt{p_\\tau(t)}$, we infer the unitary time evolution of a quantum system of fe...

  13. Davidson and classical pragmatism

    Directory of Open Access Journals (Sweden)

    Paula Rossi

    2007-06-01

    Full Text Available In this paper I wish to trace some connections between Donald Davidson's work (1917-2003 and two major representatives of the classical pragmatist movement: Charles S. Peirce (1839-1914 and William James (1842-1910. I will start with a basic characterization of classical pragmatism; then, I shall examine certain conceptions in Peirce's and James' pragmatism, in order to establish affinities with Davidson´s thought. Finally, and bearing in mind the previous con-nections, I will reflect briefly on the relevance –often unrecognized- of classical pragmatist ideas in the context of contemporary philosophi-cal discussions.

  14. 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…

  15. 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....

  16. 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.

  17. 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 ...

  18. 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.

  19. Advanced classical field theory

    CERN Document Server

    Giachetta, Giovanni; Sardanashvily, Gennadi

    2009-01-01

    Contemporary quantum field theory is mainly developed as quantization of classical fields. Therefore, classical field theory and its BRST extension is the necessary step towards quantum field theory. This book aims to provide a complete mathematical foundation of Lagrangian classical field theory and its BRST extension for the purpose of quantization. Based on the standard geometric formulation of theory of nonlinear differential operators, Lagrangian field theory is treated in a very general setting. Reducible degenerate Lagrangian theories of even and odd fields on an arbitrary smooth manifold are considered. The second Noether theorems generalized to these theories and formulated in the homology terms provide the strict mathematical formulation of BRST extended classical field theory

  20. 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

  1. 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.

  2. 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.

  3. On Noncommutative Classical Mechanics

    CERN Document Server

    Djemai, A E F

    2003-01-01

    In this work, I investigate the noncommutative Poisson algebra of classical observables corresponding to a proposed general Noncommutative Quantum Mechanics, \\cite{1}. I treat some classical systems with various potentials and some Physical interpretations are given concerning the presence of noncommutativity at large scales (Celeste Mechanics) directly tied to the one present at small scales (Quantum Mechanics) and its possible relation with UV/IR mixing.

  4. Between classical and quantum

    OpenAIRE

    2007-01-01

    The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, including over 500 references. On the assumption that quantum mechanics is universal and complete, we discuss three ways in which classical physics has so far been believed to emerge from quantum physic...

  5. Quantum and Classic Brackets

    OpenAIRE

    Kisil, Vladimir V.

    2000-01-01

    We describe an $p$-mechanical (see funct-an/9405002 and quant-ph/9610016) brackets which generate quantum (commutator) and classic (Poisson) brackets in corresponding representations of the Heisenberg group. We \\emph{do not} use any kind of semiclassic approximation or limiting procedures for $\\hbar \\to 0$. Harmonic oscillator considered within the approach. Keywords: Classic and quantum mechanics, Hamilton and Heisenberg equations, Poisson brackets, commutator, Heisenberg group.

  6. 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

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

    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

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

    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

  9. 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

  10. 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

  11. Numerical stability of finite difference algorithms for electrochemical kinetic simulations: Matrix stability analysis of the classic explicit, fully implicit and Crank-Nicolson methods and typical problems involving mixed boundary conditions

    DEFF Research Database (Denmark)

    Bieniasz, Leslaw K.; Østerby, Ole; Britz, Dieter

    1995-01-01

    The stepwise numerical stability of the classic explicit, fully implicit and Crank-Nicolson finite difference discretizations of example diffusional initial boundary value problems from electrochemical kinetics has been investigated using the matrix method of stability analysis. Special attention...

  12. 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.

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Takushi Kishida

    2015-04-01

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

  15. 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.

  16. 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.

  17. Between classical and quantum

    CERN Document Server

    Landsman, N P

    2005-01-01

    The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, including over 500 references. On the assumption that quantum mechanics is universal and complete, we discuss three ways in which classical physics has so far been believed to emerge from quantum physics, namely in the limit h -> 0 of small Planck's constant (in a finite system), in the limit of a large system, and through decoherence and consistent histores. The first limit is closely related to modern quantization theory and microlocal analysis, whereas the second involves methods of C*-algebras and the concepts of superselection sectors and macroscopic observables. In these limits, the classical world does not emerge as a sharply defined objective reality, but rather as an approximate appearance relative to certain "...

  18. Randomness: Quantum versus classical

    Science.gov (United States)

    Khrennikov, Andrei

    2016-05-01

    Recent tremendous development of quantum information theory has led to a number of quantum technological projects, e.g. quantum random generators. This development had stimulated a new wave of interest in quantum foundations. One of the most intriguing problems of quantum foundations is the elaboration of a consistent and commonly accepted interpretation of a quantum state. Closely related problem is the clarification of the notion of quantum randomness and its interrelation with classical randomness. In this short review, we shall discuss basics of classical theory of randomness (which by itself is very complex and characterized by diversity of approaches) and compare it with irreducible quantum randomness. We also discuss briefly “digital philosophy”, its role in physics (classical and quantum) and its coupling to the information interpretation of quantum mechanics (QM).

  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.

  20. 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.

  1. 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.

  2. Classical mechanics with Maxima

    CERN Document Server

    Timberlake, Todd Keene

    2016-01-01

    This book guides undergraduate students in the use of Maxima—a computer algebra system—in solving problems in classical mechanics. It functions well as a supplement to a typical classical mechanics textbook. When it comes to problems that are too difficult to solve by hand, computer algebra systems that can perform symbolic mathematical manipulations are a valuable tool. Maxima is particularly attractive in that it is open-source, multiple-platform software that students can download and install free of charge. Lessons learned and capabilities developed using Maxima are easily transferred to other, proprietary software.

  3. Covariantizing Classical Field Theories

    CERN Document Server

    López, Marco Castrillón

    2010-01-01

    We show how to enlarge the covariance group of any classical field theory in such a way that the resulting "covariantized" theory is 'essentially equivalent' to the original. In particular, our technique will render any classical field theory generally covariant, that is, the covariantized theory will be spacetime diffeomorphism-covariant and free of absolute objects. Our results thus generalize the well-known parametrization technique of Dirac and Kucha\\v{r}. Our constructions apply equally well to internal covariance groups, in which context they produce natural derivations of both the Utiyama minimal coupling and St\\"uckelberg tricks.

  4. Problems in classical mechanics

    CERN Document Server

    Katkar, L N

    2014-01-01

    Problems in classical mechanics presents a lucid treatment of the formulations of Lagrangian, Hamiltonian, and the Principles of Calculus of Variations etc. important for the study of modern physics. The study of classical mechanics prepares students to apply the principles and the mathematical tools to solve real life problems. The book also incorporates and discusses in detail topics such as Central Force Motion, Rigid Body Motion and Canonical Transformations. KEY FEATURES: Around 200 solved examples with complete mathematical theory Around 70 examples given as an exercise to test and develop students understanding The physical interpretation of the Hamiltonian is highlighted

  5. Classic Problems of Probability

    CERN Document Server

    Gorroochurn, Prakash

    2012-01-01

    "A great book, one that I will certainly add to my personal library."—Paul J. Nahin, Professor Emeritus of Electrical Engineering, University of New Hampshire Classic Problems of Probability presents a lively account of the most intriguing aspects of statistics. The book features a large collection of more than thirty classic probability problems which have been carefully selected for their interesting history, the way they have shaped the field, and their counterintuitive nature. From Cardano's 1564 Games of Chance to Jacob Bernoulli's 1713 Golden Theorem to Parrondo's 1996 Perplexin

  6. Classical Holographic Codes

    CERN Document Server

    Brehm, Enrico M

    2016-01-01

    In this work, we introduce classical holographic codes. These can be understood as concatenated probabilistic codes and can be represented as networks uniformly covering hyperbolic space. In particular, classical holographic codes can be interpreted as maps from bulk degrees of freedom to boundary degrees of freedom. Interestingly, they are shown to exhibit features similar to those expected from the AdS/CFT correspondence. Among these are a version of the Ryu-Takayanagi formula and intriguing properties regarding bulk reconstruction and boundary representations of bulk operations. We discuss the relation of our findings with expectations from AdS/CFT and, in particular, with recent results from quantum error correction.

  7. Learning Classical Music Club

    CERN Multimedia

    Learning Classical Music Club

    2010-01-01

    There is a new CERN Club called “Learning Classical Music at CERN”. We are aiming to give classical music lessons for different instruments (see link) for students from 5 to 100 years old. We are now ready to start our activities in the CERN barracks. We are now in the enrollment phase and hope to start lessons very soon ! Club info can be found in the list of CERN Club: http://user.web.cern.ch/user/Communication/SocialLifeActivities/Clubs/Clubs.html Salvatore Buontempo Club President

  8. Overuse injuries in classical ballet.

    Science.gov (United States)

    Khan, K; Brown, J; Way, S; Vass, N; Crichton, K; Alexander, R; Baxter, A; Butler, M; Wark, J

    1995-05-01

    Successful management of classical ballet dancers with overuse injuries requires an understanding of the art form, precise knowledge of anatomy and awareness of certain conditions. Turnout is the single most fundamental physical attribute in classical ballet and 'forcing turnout' frequently contributes to overuse injuries. Common presenting conditions arising from the foot and ankle include problems at the first metatarsophalangeal joint, second metatarsal stress fractures, flexor hallucis longus tendinitis and anterior and posterior ankle impingement syndromes. Persistent shin pain in dancers is often due to chronic compartment syndrome, stress fracture of the posteromedial or anterior tibia. Knee pain can arise from patellofemoral syndrome, patellar tendon insertional pathologies, or a combination of both. Hip and back problems are also prevalent in dancers. To speed injury recovery of dancers, it is important for the sports medicine team to cooperate fully. This permits the dancer to benefit from accurate diagnosis, technique correction where necessary, the full range of manual therapies to joint and soft tissue, appropriate strengthening programmes and maintenance of dance fitness during any time out of class with Pilates-based exercises and nutrition advice. Most overuse ballet conditions respond well to a combination of conservative therapies. Those dancers that do require surgical management still depend heavily on ballet-specific rehabilitation for a complete recovery.

  9. Classical trajectories and quantum tunneling

    CERN Document Server

    Ivlev, B I

    2003-01-01

    The problem of inter-band tunneling in a semiconductor (Zener breakdown) in a nonstationary and homogeneous electric field is solved exactly. Using the exact analytical solution, the approximation based on classical trajectories is studied. A new mechanism of enhanced tunneling through static non-one-dimensional barriers is proposed in addition to well known normal tunneling solely described by a trajectory in imaginary time. Under certain conditions on the barrier shape and the particle energy, the probability of enhanced tunneling is not exponentially small even for non-transparent barriers, in contrast to the case of normal tunneling.

  10. Creation of Magnetic Monopoles in Classical Scattering

    CERN Document Server

    Vachaspati, Tanmay

    2016-01-01

    We consider the creation of 't Hooft-Polyakov magnetic monopoles by scattering classical wave packets of gauge fields. An example with eight clearly separated magnetic poles created with parity violating helical initial conditions is shown. No clear separation of topological charge is observed with corresponding parity symmetric initial conditions.

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

    Directory of Open Access Journals (Sweden)

    Reda A. Alarabawy

    2016-06-01

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

  12. Heightened Olfactory Sensitivity in Young Females with Recent-Onset Anorexia Nervosa and Recovered Individuals

    DEFF Research Database (Denmark)

    Bentz, Mette; Guldberg, Johanne; Vangkilde, Signe

    2017-01-01

    INTRODUCTION: Olfaction may be related to food restriction and weight loss. However, reports regarding olfactory function in individuals with anorexia nervosa (AN) have been inconclusive. OBJECTIVE: Characterize olfactory sensitivity and identification in female adolescents and young adults...

  13. Metabolic activation of the olfactory toxicant, dichlobenil, in rat olfactory microsomes: comparative studies with p-nitrophenol.

    Science.gov (United States)

    Eriksson, C; Brittebo, E B

    1995-03-18

    The tissue-specific toxicity of the herbicide, dichlobenil (2,6-dichlorobenzonitrile), in the olfactory mucosa is related to a cytochrome P450 (P450)-dependent metabolism, depletion of glutathione and covalent binding of metabolites. Pretreatment of mice with diethyldithiocarbamate (DEDTC) protected against the dichlobenil-induced necrosis. Addition of DEDTC abolished the covalent binding of [14C]-dichlobenil to rat olfactory microsomes, whereas P4502E1-substrates such as ethanol, acetone or p-nitrophenol (NP) had no effect. The NP-hydroxylation in olfactory microsomes was > 6 times higher than that in liver microsomes and was markedly decreased following addition of dichlobenil, DEDTC or metyrapone. In liver microsomes of acetone-treated rats the NP-hydroxylation was markedly decreased following addition of DEDTC, whereas metyrapone and dichlobenil had no effect. In acetone-treated rats, the NP-hydroxylation and the metabolic activation of [14C]-dichlobenil in olfactory microsomes were decreased to 50 and 73% of untreated controls, respectively, whereas in liver microsomes these activities increased > 6 and 3.5-fold, respectively. An antibody to P4502E1 had no effect on the NP-hydroxylation or metabolic activation of [14C]-dichlobenil in olfactory microsomes, whereas the NP-hydroxylation in liver microsomes of acetone-treated rats was markedly decreased. In conclusion, the results do not support a major role for P4502E1 in the metabolic activation of dichlobenil or hydroxylation of NP in rat olfactory microsomes and suggest that these catalytic activities in the olfactory mucosa may represent a common form of P450.

  14. Odorant-stimulated phosphoinositide signaling in mammalian olfactory receptor neurons

    Science.gov (United States)

    Klasen, K.; Corey, E.A.; Kuck, F.; Wetzel, C.H.; Hatt, H.; Ache, B.W.

    2009-01-01

    Recent evidence has revived interest in the idea that phosphoinositides (PIs) may play a role in signal transduction in mammalian olfactory receptor neurons (ORNs). To provide direct evidence that odorants indeed activate PI signaling in ORNs, we used adenoviral vectors carrying two different fluorescently tagged probes, the pleckstrin homology (PH) domains of phospholipase Cδ1 (PLCδ1) and the general receptor of phosphoinositides (GRP1), to monitor PI activity in the dendritic knobs of ORNs in vivo. Odorants mobilized PI(4,5)P2/IP3 and PI(3,4,5)P3, the substrates and products of PLC and PI3K. We then measured odorant activation of PLC and PI3K in olfactory ciliary-enriched membranes in vitro using a phospholipid overlay assay and ELISAs. Odorants activated both PLC and PI3K in the olfactory cilia within 2 sec of odorant stimulation. Odorant-dependent activation of PLC and PI3K in the olfactory epithelium could be blocked by enzyme-specific inhibitors. Odorants activated PLC and PI3K with partially overlapping specificity. These results provide direct evidence that odorants indeed activate PI signaling in mammalian ORNs in a manner that is consistent with the idea that PI signaling plays a role in olfactory transduction. PMID:19781634

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Science.gov (United States)

    Garzotto, D.; De Marchis, S.

    2010-10-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Patient: Male, 41 Final Diagnosis: Olfactory neuroblastoma Symptoms: Left nasal obstruction • occasional left epistaxis • headache Medication: None Clinical Procedure: Nasal endoscopic examination • neck palpation • CT • bilateral endoscopic resection • MRI • PET-CT • postoperative radiotherapy Specialty: Otolaryngology Objective: Unusual clinical course Background: Olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma, is a rare malignant head and neck cancer thought to originate from the olfactory epithelium. It typically invades contiguous structures at presentation. We report a very rare case of multifocal and ectopic ONB. Case Report: A 41-year-old man presented with left nasal obstruction and occasional left epistaxis associated with headache. Endoscopic examination of the nasal cavities and computed tomography suggested bilateral polypoid masses. Histopathological diagnosis after endoscopic resection established bilateral olfactory neuroblastoma of the ethmoid sinuses. The patient received postoperative radiotherapy. He remains free of disease 4 years after treatment. Conclusions: To the best of our knowledge this is the second documented case of multifocal ectopic olfactory neuroblastoma. Clinicians should consider ONB in the differential diagnosis of bilateral synchronous nasal and paranasal masses to avoid delayed diagnosis. Endoscopic resection of ONB could be an option in selected cases. PMID:27097989

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

    Directory of Open Access Journals (Sweden)

    Andrea Schneider

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

  19. Analytical processing of binary mixture information by olfactory bulb glomeruli.

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    Full Text Available Odors are rarely composed of a single compound, but rather contain a large and complex variety of chemical components. Often, these mixtures are perceived as having unique qualities that can be quite different than the combination of their components. In many cases, a majority of the components of a mixture cannot be individually identified. This synthetic processing of odor information suggests that individual component representations of the mixture must interact somewhere along the olfactory pathway. The anatomical nature of sensory neuron input into segregated glomeruli with the bulb suggests that initial input of odor information into the bulb is analytic. However, a large network of interneurons within the olfactory bulb could allow for mixture interactions via mechanisms such as lateral inhibition. Currently in mammals, it is unclear if postsynaptic mitral/tufted cell glomerular mixture responses reflect the analytical mixture input, or provide the initial basis for synthetic processing with the olfactory system. To address this, olfactory bulb glomerular binary mixture representations were compared to representations of each component using transgenic mice expressing the calcium indicator G-CaMP2 in olfactory bulb mitral/tufted cells. Overall, dorsal surface mixture representations showed little mixture interaction and often appeared as a simple combination of the component representations. Based on this, it is concluded that dorsal surface glomerular mixture representations remain largely analytical with nearly all component information preserved.

  20. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    Science.gov (United States)

    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 units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well. PMID:25482234

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

    Institute of Scientific and Technical Information of China (English)

    PENG Yu; WANG YuFeng

    2009-01-01

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

  2. Adult neurogenesis in the olfactory system and neurodegenerative disease.

    Science.gov (United States)

    Gallarda, B W; Lledo, P-M

    2012-12-01

    The olfactory system is unique in many respects-two of which include the process of adult neurogenesis which continually supplies it with newborn neurons, and the fact that neurodegenerative diseases are often accompanied by a loss of smell. A link between these two phenomena has been hypothesized, but recent evidence for the lack of robust adult neurogenesis in the human olfactory system calls into question this hypothesis. Nevertheless, model organisms continue to play a critical role in the exploration of neurodegenerative disease. In part one of this review we discuss the most promising recent technological advancements for studying adult neurogenesis in the murine olfactory system. Part two continues by looking at emerging evidence related to adult neurogenesis in neurodegenerative disease studied in model organisms and the differences between animal and human olfactory system adult neurogenesis. Hopefully, the careful application of advanced research methods to the study of neurodegenerative disease in model organisms, while taking into account the recently reported differences between the human and model organism olfactory system, will lead to a better understanding of the reasons for the susceptibility of olfaction to disease.

  3. 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

  4. Strong Coupling and Classicalization

    CERN Document Server

    Dvali, Gia

    2016-01-01

    Classicalization is a phenomenon in which a theory prevents itself from entering into a strong-coupling regime, by redistributing the energy among many weakly-interacting soft quanta. In this way, the scattering process of some initial hard quanta splits into a large number of soft elementary processes. In short, the theory trades the strong coupling for a high-multiplicity of quanta. At very high energies, the outcome of such a scattering experiment is a production of soft states of high occupation number that are approximately classical. It is evident that black hole creation in particle collision at super-Planckian energies is a result of classicalization, but there is no a priory reason why this phenomenon must be limited to gravity. If the hierarchy problem is solved by classicalization, the LHC has a chance of detecting a tower of new resonances. The lowest-lying resonances must appear right at the strong coupling scale in form of short-lived elementary particles. The heavier members of the tower must b...

  5. Classical Mythology. Fourth Edition.

    Science.gov (United States)

    Morford, Mark P. O.; Lenardon, Robert J.

    Designed for students with little or no background in classical literature, this book introduces the Greek and Roman myths of creation, myths of the gods, Greek sagas and local legends, and presents contemporary theories about the myths. Drawing on Homer, Hesiod, Pindar, Vergil, and others, the book provides many translations and paraphrases of…

  6. Classical galactosaemia revisited

    NARCIS (Netherlands)

    A.M. Bosch

    2006-01-01

    Classical galactosaemia (McKusick 230400) is an: autosomal recessive disorder of galactose metabolism, caused by a deficiency of the enzyme galactose-1-phosphate uridyltransferase (GALT; EC 2.7.712). Most patients present in the neonatal period, after ingestion of galactose, with jaundice, hepatospl

  7. Classicism and Romanticism.

    Science.gov (United States)

    Huddleston, Gregory H.

    1993-01-01

    Describes one teacher's methods for introducing to secondary English students the concepts of Classicism and Romanticism in relation to pictures of gardens, architecture, music, and literary works. Outlines how the unit leads to a writing assignment based on collected responses over time. (HB)

  8. Mecanica Clasica (Classical Mechanics)

    OpenAIRE

    Rosu, H. C.

    1999-01-01

    First Internet graduate course on Classical Mechanics in Spanish (Castellano). This is about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. English and Romanian versions are in (slow) progress and hopefully will be arXived. For a similar course on Quantum Mechanics, see physics/9808031

  9. Nuclear motion is classical

    CERN Document Server

    Frank, Irmgard

    2016-01-01

    The notion from ab-initio molecular dynamics simulations that nuclear motion is best described by classical Newton dynamics instead of the time-dependent Schr{\\"o}dinger equation is substantiated. In principle a single experiment should bring clarity. Caution is however necessary, as temperature dependent effects must be eliminated when trying to determine the existence of a zero-point energy.

  10. Mecanica Clasica (Classical Mechanics)

    CERN Document Server

    Rosu, H C

    1999-01-01

    First Internet undergraduate course on Classical Mechanics in Spanish (Castellano). This is about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. English and Romanian versions are in (slow) progress and hopefully will be arXived. For a similar course on Quantum Mechanics, see physics/9808031

  11. Classical Mechanics Laboratory

    Science.gov (United States)

    Brosing, Juliet W.

    2006-12-01

    At Pacific University we have included a lab with our upper division Classical Mechanics class. We do a combination of physical labs (air resistance, harmonic motion, amusement park physics), Maple labs (software), and projects. Presentation of some of the labs, results and challenges with this course will be included.

  12. Children's Classics. Fifth Edition.

    Science.gov (United States)

    Jordan, Alice M.

    "Children's Classics," a 1947 article by Alice M. Jordan reprinted from "The Horn Book Magazine," examines the dynamics and appeal of some of the most famous books for young readers, including "Alice in Wonderland,""The Wind in the Willows,""Robinson Crusoe," and "Andersen's Fairy Tales." Paul Hein's annotated bibliography, a revision of Jordan's…

  13. The source of spontaneous activity in the main olfactory bulb of the rat.

    Directory of Open Access Journals (Sweden)

    Josif Stakic

    Full Text Available INTRODUCTION: In vivo, most neurons in the main olfactory bulb exhibit robust spontaneous activity. This paper tests the hypothesis that spontaneous activity in olfactory receptor neurons drives much of the spontaneous activity in mitral and tufted cells via excitatory synapses. METHODS: Single units were recorded in vivo from the main olfactory bulb of a rat before, during, and after application of lidocaine to the olfactory nerve. The effect of lidocaine on the conduction of action potentials from the olfactory epithelium to the olfactory bulb was assessed by electrically stimulating the olfactory nerve rostral to the application site and monitoring the field potential evoked in the bulb. RESULTS: Lidocaine caused a significant decrease in the amplitude of the olfactory nerve evoked field potential that was recorded in the olfactory bulb. By contrast, the lidocaine block did not significantly alter the spontaneous activity of single units in the bulb, nor did it alter the field potential evoked by electrical stimulation of the lateral olfactory tract. Lidocaine block also did not change the temporal patters of action potential or their synchronization with respiration. CONCLUSIONS: Spontaneous activity in neurons of the main olfactory bulb is not driven mainly by activity in olfactory receptor neurons despite the extensive convergence onto mitral and tufted cells. These results suggest that spontaneous activity of mitral and tufted is either an inherent property of these cells or is driven by centrifugal inputs to the bulb.

  14. Olfactory coding in antennal neurons of the malaria mosquito, Anopheles gambiae

    NARCIS (Netherlands)

    Qiu, Y.T.; Loon, van J.J.A.; Takken, W.; Meijerink, J.; Smid, H.M.

    2006-01-01

    Olfactory receptor neurons (ORNs) in the antenna of insects serve to encode odors in action potential activity conducted to the olfactory lobe of the deuterocerebrum. We performed an analysis of the electrophysiological responses of olfactory neurons in the antennae of the female malaria mosquito An

  15. File list: Pol.Oth.50.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  17. File list: Oth.Oth.05.AllAg.Olfactory_epithelium [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

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    Lifescience Database Archive (English)

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