The Experts below are selected from a list of 19008 Experts worldwide ranked by ideXlab platform
Thomas Hummel - One of the best experts on this subject based on the ideXlab platform.
-
electro olfactograms in humans in response to ortho and retronasal chemosensory stimulation
Chemosensory Perception, 2017Co-Authors: Thomas Hummel, Roberto Pellegrino, Stefan HeilmannAbstract:Aim Ortho- and retronasal Olfaction represent two aspects of a shared sensory system yet evoke different sensations. The differences between ortho- and retronasal Olfaction have triggered a number of studies during the past years, which pointed towards a decreased sensitivity to odors presented through the retronasal olfactory pathway. Especially intensity was reported to be lower after retronasal olfactory stimulation. The aim of this study was to investigate how this compares to activation at the level of the olfactory epithelium in humans.
-
Olfaction as a marker for depression
Journal of Neurology, 2017Co-Authors: Ilona Croy, Thomas HummelAbstract:Olfactory and emotional higher processing pathways share common anatomical substrates. Hence, depression is often accompanied by alterations in olfactory function. These alterations are negative in nature and may involve decreased activation in olfactory eloquent structures or decreased volume in the olfactory bulb (OB). We suggest that Olfaction and depression interact in two ways. First, olfactory function in depression is impaired as a consequence of reduced olfactory attention and diminished olfactory receptor turnover rates. Second, the OB may constitute a marker for enhanced vulnerability to depression. Closer analysis of these interactions may help to explain observed experimental data, as well as to elucidate new therapeutic strategies involving Olfaction. Because of the difficulties to disentangle cause from consequence in the relationship between Olfaction and depression, longitudinal and intervention studies are necessary to elucidate this further.
-
Olfaction in allergic rhinitis a systematic review
The Journal of Allergy and Clinical Immunology, 2015Co-Authors: Oris A Stuck, Thomas HummelAbstract:Olfactory dysfunction is a key symptom in patients with allergic rhinitis (AR). Despite the implications for quality of life, relatively few articles have tested olfactory function in their investigations. The current systematic review aimed to investigate the following 2 questions: (1) What does AR do to human Olfaction? (2) How effective is the treatment of AR in restoring the sense of smell? A comprehensive literature search was performed, and human studies of any design were included. A total of 420 articles were identified, and 36 articles were considered relevant. Data indicate that the frequency of olfactory dysfunction increases with the duration of the disorder, and most studies report a frequency in the range of 20% to 40%. Although olfactory dysfunction does not appear to be very severe in patients with AR, its presence seems to increase with the severity of the disease. There is very limited evidence that antihistamines improve olfactory function. In addition, there is limited evidence that topical steroids improve the sense of smell, especially in patients with seasonal AR. This is also the case for specific immunotherapy. However, many questions remain unanswered because randomized controlled trials are infrequent and only a few studies rely on quantitative measurement of olfactory function.
-
learning about the functions of the olfactory system from people without a sense of smell
PLOS ONE, 2012Co-Authors: Ilona Croy, Basile Nicolas Landis, Simona Negoias, Lenka Martinec Novakova, Thomas HummelAbstract:The olfactory system provides numerous functions to humans, influencing ingestive behavior, awareness of environmental hazards and social communication. Approximately ⅕ of the general population exhibit an impaired sense of smell. However, in contrast to the many affected, only few patients complain of their impairment. So how important is it for humans to have an intact sense of smell? Or is it even dispensable, at least in the Western world? To investigate this, we compared 32 patients, who were born without a sense of smell (isolated congenital anosmia - ICA) with 36 age-matched controls. A broad questionnaire was used, containing domains relevant to Olfaction in daily life, along with a questionnaire about social relationships and the BDI-questionnaire. ICA-patients differed only slightly from controls in functions of daily life related to Olfaction. These differences included enhanced social insecurity, increased risk for depressive symptoms and increased risk for household accidents. In these domains the sense of Olfaction seems to play a key role.
-
tests for screening olfactory and gustatory function in school age children
Otolaryngology-Head and Neck Surgery, 2008Co-Authors: David G Laing, Carolina Segovia, Therese Fark, Olga N Laing, Anthony L Jinks, Julia Nikolaus, Thomas HummelAbstract:OBJECTIVE: Determine the suitability of three tests based on the identification of familiar odors and tastes for the clinical assessment of Olfaction and gustation in children. STUDY DESIGN AND SETTING: A total of 232 children aged 5 to 7 years from Sydney public schools and 56 adults aged 18 to 51 years participated in a cross-sectional study. RESULTS: The children demonstrated they can identify the majority of the 16 test odorants and 4 common tastes that describe gustatory function. The response distributions obtained for each test provide the basis for a set of normative data for young children. CONCLUSION: Olfactory and gustatory function can be determined in school-age children using the three tests described. SIGNIFICANCE: Currently no satisfactory clinical tests of Olfaction and gustation for children or normative data are available. The present study resolves these shortcomings and provides normative data that can be used in the diagnosis of olfactory and gustatory impairment in school-age children.
We Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Humans with stereo Olfaction
'Proceedings of the National Academy of Sciences', 2020Co-Authors: Wu Yuli, Che Kepu, Ye Yuting, Zhang Tao, We ZhouAbstract:Human navigation relies on inputs to our paired eyes and ears. Although we also have two nasal passages, there has been little empirical indication that internostril differences yield directionality in human Olfaction without involving the trigeminal system. By using optic flow that captures the pattern of apparent motion of surface elements in a visual scene, we demonstrate through formal psychophysical testing that a moderate binaral concentration disparity of a nontrigeminal odorant consistently biases recipients' perceived direction of self-motion toward the higherconcentration side, despite that they cannot verbalize which nostril smells a stronger odor. We further show that the effect depends on the internostril ratio of odor concentrations and not the numeric difference in concentration between the two nostrils. Taken together, our findings provide behavioral evidence that humans smell in stereo and subconsciously utilize stereo olfactory cues in spatial navigation
-
humans navigate with stereo Olfaction
Proceedings of the National Academy of Sciences of the United States of America, 2020Co-Authors: Kepu Che, Tao Zhang, We ZhouAbstract:Human navigation relies on inputs to our paired eyes and ears. Although we also have two nasal passages, there has been little empirical indication that internostril differences yield directionality in human Olfaction without involving the trigeminal system. By using optic flow that captures the pattern of apparent motion of surface elements in a visual scene, we demonstrate through formal psychophysical testing that a moderate binaral concentration disparity of a nontrigeminal odorant consistently biases recipients’ perceived direction of self-motion toward the higher-concentration side, despite that they cannot verbalize which nostril smells a stronger odor. We further show that the effect depends on the internostril ratio of odor concentrations and not the numeric difference in concentration between the two nostrils. Taken together, our findings provide behavioral evidence that humans smell in stereo and subconsciously utilize stereo olfactory cues in spatial navigation.
-
Olfaction modulates visual perception in binocular rivalry
Current Biology, 2010Co-Authors: We Zhou, Yi Jiang, Denise CheAbstract:Vision is widely accepted as the dominant sense in larger primates including humans, whereas Olfaction is often considered a vestigial sense yielding only obscure object representations [1]. It is well documented that vision drives olfactory perception [2, 3], but there has been little indication that Olfaction could modulate visual perception. Here we introduce smells to a well-established visual phenomenon termed binocular rivalry, perceptual alternations that occur when distinctively different images are separately presented to the two eyes [4]. We show that an odorant congruent to one of the competing images prolongs the time that image is visible and shortens its suppression time in a manner that is automatic, essentially independent of cognitive control, and partly subconscious. Our findings provide the first direct evidence that an olfactory cue biases the dynamic process of binocular rivalry, thereby demonstrating olfactory modulation of visual perception-an effect that has been hitherto unsuspected.
Leonardo José Gil Barcellos - One of the best experts on this subject based on the ideXlab platform.
-
effects of znso4 induced peripheral anosmia on zebrafish behavior and physiology
Behavioural Brain Research, 2017Co-Authors: Murilo S. De Abreu, Ana C.v.v. Giacomini, Leonardo José Gil Barcellos, Allan V. Kalueff, Rubens RodriguezAbstract:Abstract Olfaction plays a key role in modulating behavioral and physiological responses of various animal species, including fishes. Olfactory deficits can be induced in fish experimentally, and utilized to examine the role of Olfaction in their normal and pathological behaviors. Here, we examine whether experimental anosmia, evoked by ZnSO4 in adult zebrafish can be associated with behavioral and/or physiological responses. We show that experimental ZnSO4-induced anosmia caused acute, but not prolonged, anxiogenic-like effects on zebrafish behavior tested in the novel tank test. The procedure also elevated whole-body cortisol levels in zebrafish. Moreover, ZnSO4 treatment, but not sham, produced damage to olfactory epithelium, inducing overt basal cell vacuolization and intercellular edema. The loss of Olfaction, assessed by the fish food preference behavior in the aquatic Y-maze, was present 1 h, but not 24 h, after the treatment. Collectively, this suggests that transient experimental anosmia by ZnSO4 modulates zebrafish behavior and Olfaction, which can be used to evoke and assess their stress-related anxiety-like states.
-
the smell of anxiety behavioral modulation by experimental anosmia in zebrafish
Physiology & Behavior, 2016Co-Authors: Murilo S. De Abreu, Ana C.v.v. Giacomini, Allan V. Kalueff, Leonardo José Gil BarcellosAbstract:Olfaction is strongly involved in the regulation of fish behavior, including reproductive, defensive, social and migration behaviors. In fish, anosmia (the lack of Olfaction) can be induced experimentally, impairing their ability to respond to various olfactory stimuli. Here, we examine the effects of experimental lidocaine-induced anosmia on anxiety-like behavior and whole-body cortisol levels in adult zebrafish (Danio rerio). We show that experimentally-induced anosmia reduces anxiolytic-like behavioral effects of fluoxetine and seems to interact with anxiogenic effect of stress also paralleling cortisol responses in zebrafish. These findings provide first experimental evidence that temporary anosmia modulates anxiety-like behaviors and physiology in adult zebrafish.
Mehme Ozbil - One of the best experts on this subject based on the ideXlab platform.
-
implausibility of the vibrational theory of Olfaction
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Eric Lock, Seogjoo Jang, Hiroaki Matsunami, Sivakuma Sekhara, Erenice Dethie, Mehmed Z Ertem, Sivaji Gundala, Stephene N Lodge, Mehme OzbilAbstract:The vibrational theory of Olfaction assumes that electron transfer occurs across odorants at the active sites of odorant receptors (ORs), serving as a sensitive measure of odorant vibrational frequencies, ultimately leading to olfactory perception. A previous study reported that human subjects differentiated hydrogen/deuterium isotopomers (isomers with isotopic atoms) of the musk compound cyclopentadecanone as evidence supporting the theory. Here, we find no evidence for such differentiation at the molecular level. In fact, we find that the human musk-recognizing receptor, OR5AN1, identified using a heterologous OR expression system and robustly responding to cyclopentadecanone and muscone, fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse ORs, responded similarly to normal, deuterated, and 13C isotopomers of their respective ligands, paralleling our results with the musk receptor OR5AN1. These findings suggest that the proposed vibration theory does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other ORs examined. Also, contrary to the vibration theory predictions, muscone-d30 lacks the 1,380- to 1,550-cm−1 IR bands claimed to be essential for musk odor. Furthermore, our theoretical analysis shows that the proposed electron transfer mechanism of the vibrational frequencies of odorants could be easily suppressed by quantum effects of nonodorant molecular vibrational modes. These and other concerns about electron transfer at ORs, together with our extensive experimental data, argue against the plausibility of the vibration theory.
Mehmed Z Ertem - One of the best experts on this subject based on the ideXlab platform.
-
implausibility of the vibrational theory of Olfaction
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Eric Lock, Seogjoo Jang, Hiroaki Matsunami, Sivakuma Sekhara, Erenice Dethie, Mehmed Z Ertem, Sivaji Gundala, Stephene N Lodge, Mehme OzbilAbstract:The vibrational theory of Olfaction assumes that electron transfer occurs across odorants at the active sites of odorant receptors (ORs), serving as a sensitive measure of odorant vibrational frequencies, ultimately leading to olfactory perception. A previous study reported that human subjects differentiated hydrogen/deuterium isotopomers (isomers with isotopic atoms) of the musk compound cyclopentadecanone as evidence supporting the theory. Here, we find no evidence for such differentiation at the molecular level. In fact, we find that the human musk-recognizing receptor, OR5AN1, identified using a heterologous OR expression system and robustly responding to cyclopentadecanone and muscone, fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse ORs, responded similarly to normal, deuterated, and 13C isotopomers of their respective ligands, paralleling our results with the musk receptor OR5AN1. These findings suggest that the proposed vibration theory does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other ORs examined. Also, contrary to the vibration theory predictions, muscone-d30 lacks the 1,380- to 1,550-cm−1 IR bands claimed to be essential for musk odor. Furthermore, our theoretical analysis shows that the proposed electron transfer mechanism of the vibrational frequencies of odorants could be easily suppressed by quantum effects of nonodorant molecular vibrational modes. These and other concerns about electron transfer at ORs, together with our extensive experimental data, argue against the plausibility of the vibration theory.
