RESUMO
The olfactory system combines input from multiple receptor types to represent odor information, but there are few explicit examples relating olfactory receptor (OR) activity patterns to odor perception. To uncover these relationships, we performed genome-wide scans on odor-perception phenotypes for ten odors in 1000 Han Chinese and validated results for six of these odors in an ethnically diverse population (n = 364). In both populations, consistent with previous studies, we replicated three previously reported associations (ß-ionone/OR5A1, androstenone/OR7D4, cis-3-hexen-1-ol/OR2J3 LD-band), but not for odors containing aldehydes, suggesting that olfactory phenotype/genotype studies are robust across populations. Two novel associations between an OR and odor perception contribute to our understanding of olfactory coding. First, we found a SNP in OR51B2 that associated with trans-3-methyl-2-hexenoic acid, a key component of human underarm odor. Second, we found two linked SNPs associated with the musk Galaxolide in a novel musk receptor, OR4D6, which is also the first human OR shown to drive specific anosmia to a musk compound. We noticed that SNPs detected for odor intensity were enriched with amino acid substitutions, implying functional changes of odor receptors. Furthermore, we also found that the derived alleles of the SNPs tend to be associated with reduced odor intensity, supporting the hypothesis that the primate olfactory gene repertoire has degenerated over time. This study provides information about coding for human body odor, and gives us insight into broader mechanisms of olfactory coding, such as how differential OR activation can converge on a similar percept.
Assuntos
Percepção Olfatória , Polimorfismo de Nucleotídeo Único , Receptores Odorantes , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Povo Asiático/genética , Benzopiranos/farmacologia , Odor Corporal , Caproatos/farmacologia , Percepção Olfatória/efeitos dos fármacos , Percepção Olfatória/genética , Receptores Odorantes/genética , Reprodutibilidade dos Testes , Olfato/genéticaRESUMO
Enzyme-assisted solvent extraction (EASE) of Paeonia suffruticosa Andr. seed oil (PSO) was optimized by response surface methodology (RSM). The fatty acid composition and anti-Alzheimer's disease (AD) activity of PSO were analyzed. An enzyme mixture composed of cellulase and hemicellulase (1:1, w/w) was most effective in determining the extraction yield of PSO. The ideal extraction conditions were a pH value of 5.1, an enzymolysis time of 68 min, and a temperature of 50â. The average extraction yield of PSO was 38.2 mL/100 g, 37.4% higher than that of untreated peony seed (27.8 mL/100 g). The fatty acid composition of PSO under optimal conditions for EASE was analyzed by gas chromatography-mass spectrometry (GC-MS). The predominant unsaturated fatty acids of PSO were determined to be more than 90.00%, including n-3 α-linolenic acid (43.33%), n-6 linoleic acid (23.40%) and oleic acid (23.59%). In this experiment, the anti-AD effect of PSO was also analyzed by performing learning and memory ability tests with Drosophila. PSO retarded the decrease in climbing ability in AD Drosophila. The 1% and 5% PSO groups were significantly different from the model group (b p < 0.05). The smell short-term memory ability test revealed the number of Drosophila in barrier and barrier-free centrifuge tubes in each group. PSO feeding improved learning and memory in AD Drosophila, with the highest number entering the barrierfree centrifuge tube. The performance index (PI) measured by the Pavlov olfactory avoidance conditioning test also demonstrated the effect of PSO on the learning and memory abilities of Drosophila. The PI of the PSO group was significantly increased compared to that of the model group. HE-stained brain tissue sections of AD Drosophila showed higher neurodegenerative changes, while PSO significantly reduced neurodegenerative damage. These results indicated that PSO can significantly improve the cognitive function of AD Drosophila and may help to prevent AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Nootrópicos/uso terapêutico , Paeonia/química , Óleos de Plantas/uso terapêutico , Sementes/química , Doença de Alzheimer/patologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Drosophila/efeitos dos fármacos , Ácidos Graxos/análise , Glicosídeo Hidrolases/química , Química Verde/métodos , Aprendizagem/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Nootrópicos/análise , Nootrópicos/química , Nootrópicos/isolamento & purificação , Percepção Olfatória/efeitos dos fármacos , Óleos de Plantas/análise , Óleos de Plantas/química , Óleos de Plantas/isolamento & purificação , Extração em Fase Sólida/métodosRESUMO
American trypanosomiasis, or Chagas disease, is transmitted by both domestic and sylvatic species of Triatominae which use sensory cues to locate their vertebrate hosts. Among them, odorants have been shown to play a key role. Previous work revealed morphological differences in the sensory apparatus of different species of Triatomines, but to date a comparative functional study of the olfactory system is lacking. After examining the antennal sensilla with scanning electronic microscopy (SEM), we compared olfactory responses of Rhodnius prolixus and the sylvatic Rhodnius brethesi using an electrophysiological approach. In electroantennogram (EAG) recordings, we first showed that the antenna of R. prolixus is highly responsive to carboxylic acids, compounds found in their habitat and the headspace of their vertebrate hosts. We then compared responses from olfactory sensory neurons (OSNs) housed in the grooved peg sensilla of both species, as these are tuned to these compounds using single-sensillum recordings (SSRs). In R. prolixus, the SSR responses revealed a narrower tuning breath than its sylvatic sibling, with the latter showing responses to a broader range of chemical classes. Additionally, we observed significant differences between these two species in their response to particular volatiles, such as amyl acetate and butyryl chloride. In summary, the closely related, but ecologically differentiated R. prolixus and R. brethesi display distinct differences in their olfactory functions. Considering the ongoing rapid destruction of the natural habitat of sylvatic species and the likely shift towards environments shaped by humans, we expect that our results will contribute to the design of efficient vector control strategies in the future.
Assuntos
Antenas de Artrópodes/fisiologia , Ácidos Carboxílicos/farmacologia , Rhodnius/classificação , Rhodnius/fisiologia , Animais , Antenas de Artrópodes/efeitos dos fármacos , Doença de Chagas/transmissão , Eletrofisiologia , Insetos Vetores/fisiologia , Odorantes , Percepção Olfatória/efeitos dos fármacosRESUMO
Humans sense taste and smell of various chemical substances through approximately 430 chemosensory receptors. The overall picture of ligand-chemosensory receptor interactions has been partially clarified because of numerous interactions. This study presents a new method that enables a rapid and simple screening of chemosensory receptors. It would be useful for identifying chemosensory receptors activated by taste and odor substances.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Percepção Olfatória/efeitos dos fármacos , Percepção Gustatória/efeitos dos fármacosRESUMO
Mass trapping of gravid females represents one promising strategy for the development of sustainable tools against Aedes aegypti. However, this technique requires the development of effective odorant lures that can compete with natural breeding sites. The presence of conspecific larvae has been shown to stimulate oviposition. Hence, we evaluated the role of four major molecules previously identified from Ae. aegypti larvae (isovaleric, myristoleic, myristic [i.e. tetradecanoic], and pentadecanoic acids) on the oviposition of conspecific females, as well as their olfactory perception to evaluate their range of detection. Using flight cage assays, the preference of gravid females to oviposit in water that previously contained larvae (LHW) or containing the four larval compounds was evaluated. Then, compounds and doses inducing the highest stimulation were challenged for their efficacy against LHW. Only isovaleric acid elicited antennal response, suggesting that the other compounds may act as taste cues. Pentadecanoic acid induced significant oviposition stimulation, especially when dosed at 10 ppm. Myristoleic acid and isovaleric acid deterred oviposition at 10 and 100 ppm, while no effect on oviposition was observed with myristic acid irrespectively of the dose tested. When the four compounds were pooled to mimic larvae's chemical signature, they favored oviposition at 1 ppm but negatively affected egg-laying at higher concentrations. When properly dosed, pentadecanoic acid and the blend of compounds may be promising lures for ovitraps as they could compete with LHW. Due to their low volatility, their effect should be further evaluated under field conditions, in addition with long-range attractants for developing effective tools against gravid females.
Assuntos
Aedes/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Ácidos Graxos Monoinsaturados/farmacologia , Ácidos Graxos/farmacologia , Hemiterpenos/farmacologia , Ácido Mirístico/farmacologia , Oviposição/efeitos dos fármacos , Ácidos Pentanoicos/farmacologia , Animais , Sinais (Psicologia) , Feminino , Odorantes , Percepção Olfatória/efeitos dos fármacosRESUMO
Food neophobia is a behavior observed in rodents involving reduced consumption of a novel food or drink. In the absence of negative post-ingestive consequences, consumption increases with exposure (attenuation of neophobia), which is seen as an associative safe memory. Olfaction and gustation are sensory modalities essential for the development of a food preference. However, little is known about the neural mechanisms underlying neophobia to a food-related odor stimulus. In the present study, we examined the effect of pharmacological inactivation of the ventral hippocampus (vHPC) on neophobia to orally consumed solutions in rats using muscimol, a gamma aminobutyric acid type A receptor agonist. Two different types of solutions, almond odor (benzaldehyde) and sweet taste (saccharin), were prepared. In the results, microinjections of muscimol into the bilateral vHPC before the first odor and taste exposures did not alter the neophobic reactions of the rats to each stimulus. However, in the second odor, but not taste, exposure, the muscimol-injected rats showed higher consumption in comparison to that observed in the control rats, suggesting that the vHPC inactivation facilitates the attenuation of odor neophobia. On the other hand, intra-vHPC muscimol microinjections after the first odor and taste exposures did not facilitate consumption at the second exposures. These results indicate that neural activations within vHPC during orally consuming a novel odor, but not taste, solution play an inhibitory role in the subsequent attenuation of neophobia.
Assuntos
Comportamento Animal/fisiologia , Preferências Alimentares/fisiologia , Agonistas de Receptores de GABA-A/farmacologia , Hipocampo/efeitos dos fármacos , Muscimol/farmacologia , Percepção Olfatória/fisiologia , Percepção Gustatória/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Preferências Alimentares/efeitos dos fármacos , Agonistas de Receptores de GABA-A/administração & dosagem , Masculino , Muscimol/administração & dosagem , Percepção Olfatória/efeitos dos fármacos , Ratos , Ratos Wistar , Percepção Gustatória/efeitos dos fármacosRESUMO
Melatonin MT1 and MT2 receptors are expressed in the glomerular layer of the olfactory bulb (OB); however, the role of these receptors has not been evaluated until now. Considering the association of the OB with olfactory and depressive disorders in Parkinson's disease (PD), we sought to investigate the involvement of melatonin receptors in these non-motor disturbances in an intranigral 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD. We demonstrate the presence of functional melatonin receptors in dopaminergic neurons of the glomerular layer. Local administration of melatonin (MLT, 1 µg/µl), luzindole (LUZ, 5 µg/µl) or the MT2-selective receptor drug 4-P-PDOT (5 µg/µl) reversed the depressive-like behavior elicited by 6-OHDA. Sequential administration of 4-P-PDOT and MLT (5 µg/µl, 1 µg/µl) promoted additive antidepressant-like effects. In the evaluation of olfactory discrimination, LUZ induced an olfactory impairment when associated with the nigral lesion-induced impairment. Thus, our results suggest that melatonin MT2 receptors expressed in the glomerular layer are involved in depressive-like behaviors and in olfactory function associated with PD.
Assuntos
Anosmia/metabolismo , Comportamento Animal , Transtorno Depressivo/metabolismo , Neurônios Dopaminérgicos/metabolismo , Bulbo Olfatório/metabolismo , Transtornos Parkinsonianos/metabolismo , Receptor MT2 de Melatonina/metabolismo , Animais , Anosmia/etiologia , Anosmia/fisiopatologia , Anosmia/psicologia , Comportamento Animal/efeitos dos fármacos , Transtorno Depressivo/etiologia , Transtorno Depressivo/fisiopatologia , Transtorno Depressivo/psicologia , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Masculino , Melatonina/farmacologia , Bulbo Olfatório/efeitos dos fármacos , Bulbo Olfatório/fisiopatologia , Percepção Olfatória/efeitos dos fármacos , Oxidopamina , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/fisiopatologia , Transtornos Parkinsonianos/psicologia , Ratos Wistar , Receptor MT2 de Melatonina/efeitos dos fármacos , Transdução de Sinais , Olfato/efeitos dos fármacos , Natação , Tetra-Hidronaftalenos/farmacologia , Triptaminas/farmacologiaRESUMO
Caffeine has been demonstrated to enhance olfactory function in rodents, but to date, the sparse research in humans has not shown any equivalent effects. However, due to the methodological nature of those human studies, a number of questions remain unanswered, which the present study aimed to investigate. Using a double-blind experimental design, participants (n = 40) completed baseline mood measures, standardised threshold and identification tests and were then randomly allocated to receive a capsule containing either 100 mg of caffeine or placebo, followed by the same olfactory tests and mood measures. Results revealed that despite a trend toward elevated arousal following caffeine for habitual caffeine consumers, there were no changes in odour function. In contrast, for non-caffeine consumers, caffeine acted to enhance odour (threshold) sensitivity but reduce odour identification. Overall, these findings demonstrate a complex profile of effects of caffeine on odour function and, given the evidence from the wider caffeine literature, it is proposed that the effects of caffeine might be limited to older populations.
Assuntos
Afeto/efeitos dos fármacos , Cafeína/farmacologia , Percepção Olfatória/efeitos dos fármacos , Adolescente , Adulto , Nível de Alerta/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Masculino , Limiar Sensorial , Adulto JovemRESUMO
The beech leaf-mining weevil, Orchestes fagi, is a common pest of European beech, Fagus sylvatica, and has recently become established in Nova Scotia, Canada where it similarly infests American beech, F. grandifolia. We collected volatile organic compounds (VOCs) emitted by F. grandifolia leaves at five developmental stages over one growing season and simultaneously analyzed them for volatile emissions and O. fagi antennal response using gas chromatography-electroantennographic detection (GC-EAD). Volatile profiles changed significantly throughout the growing season, shifting from primarily ß-caryophyllene, methyl jasmonate, and simple monoterpene emissions to dominance of the bicyclic monoterpene sabinene during maturity. Two VOCs dominant during bud burst, (R)-(+)-limonene and geranyl-p-cymene, may be of biological relevance due to the highly specific oviposition period of O. fagi at this stage though antennal responses were inconclusive. Senescence showed a decrease in blend complexity with an increase in (Z)-3-hexenyl acetate and (Z)-3-hexen-1-ol as well as a resurgence of α-terpinene and geranyl-p-cymene. We present a novel electroantennal preparation for O. fagi. Antennae of both male and female O. fagi responded to the majority of detectable peaks for host volatiles presented via GC-EAD. Females displayed greater overall sensitivities and less specificity to host volatiles and it is hypothesized that this translates to more generalist olfaction than males. It is clear that olfactory cues are important physiologically though their implications on behaviour are still unknown. The results presented in this study provide a baseline and tools on which to connect the complex and highly time-specific phenology of both F. grandifolia and the destructive pest O. fagi through which olfactory-based lures can be investigated for monitoring systems.
Assuntos
Fagus/química , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/farmacologia , Gorgulhos/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Fenômenos Eletrofisiológicos , Fagus/crescimento & desenvolvimento , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Larva/fisiologia , Masculino , América do Norte , Percepção Olfatória/efeitos dos fármacosRESUMO
Insect pollination is essential to many unmanaged and agricultural systems and as such is a key element in food production. However, floral scents that pollinating insects rely on to locate host plants may be altered by atmospheric oxidants, such as ozone, potentially making these cues less attractive or unrecognizable to foraging insects and decreasing pollinator efficacy. We demonstrate that levels of tropospheric ozone commonly found in many rural areas are sufficient to disrupt the innate attraction of the tobacco hawkmoth Manduca sexta to the odor of one of its preferred flowers, Nicotiana alata. However, we further find that visual navigation together with associative learning can offset this disruption. Foraging moths that initially find an ozone-altered floral scent unattractive can target an artificial flower using visual cues and associate the ozone-altered floral blend with a nectar reward. The ability to learn ozone-altered floral odors may enable pollinators to maintain communication with their co-evolutionary partners and reduce the negative impacts that anthropogenically elevated oxidants may have on plant-pollinator systems.
Assuntos
Comportamento Animal/efeitos dos fármacos , Flores/fisiologia , Manduca/fisiologia , Nicotiana/fisiologia , Percepção Olfatória/efeitos dos fármacos , Ozônio/toxicidade , Animais , Flores/química , Flores/efeitos dos fármacos , Odorantes/análise , Polinização , Nicotiana/efeitos dos fármacosAssuntos
Mosquitos Vetores/fisiologia , Percepção Olfatória/fisiologia , Animais , Distinções e Prêmios , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Humanos , Repelentes de Insetos/farmacologia , Transtornos do Olfato/diagnóstico , Percepção Olfatória/efeitos dos fármacosRESUMO
Odor landscapes contain complex blends of molecules that each activate unique, overlapping populations of olfactory sensory neurons (OSNs). Despite the presence of hundreds of OSN subtypes in many animals, the overlapping nature of odor inputs may lead to saturation of neural responses at the early stages of stimulus encoding. Information loss due to saturation could be mitigated by normalizing mechanisms such as antagonism at the level of receptor-ligand interactions, whose existence and prevalence remains uncertain. By imaging OSN axon terminals in olfactory bulb glomeruli as well as OSN cell bodies within the olfactory epithelium in freely breathing mice, we find widespread antagonistic interactions in binary odor mixtures. In complex mixtures of up to 12 odorants, antagonistic interactions are stronger and more prevalent with increasing mixture complexity. Therefore, antagonism is a common feature of odor mixture encoding in OSNs and helps in normalizing activity to reduce saturation and increase information transfer.
Assuntos
Misturas Complexas/farmacologia , Odorantes , Percepção Olfatória/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Olfato/fisiologia , Animais , Antagonismo de Drogas , Feminino , Ligantes , Masculino , Camundongos , Microscopia de Fluorescência por Excitação Multifotônica , Bulbo Olfatório/citologia , Bulbo Olfatório/diagnóstico por imagem , Bulbo Olfatório/fisiologia , Mucosa Olfatória/citologia , Mucosa Olfatória/efeitos dos fármacos , Mucosa Olfatória/metabolismo , Percepção Olfatória/efeitos dos fármacos , Neurônios Receptores Olfatórios/efeitos dos fármacos , Terminações Pré-Sinápticas/fisiologia , Receptores Odorantes/metabolismo , Respiração , Olfato/efeitos dos fármacosRESUMO
Intelligent systems in nature like the mammalian nervous system benefit from adaptable inputs that can tailor response profiles to their environment that varies in time and space. Study of such plasticity, in all its manifestations, forms a pillar of classical and modern neuroscience. This study is concerned with a novel form of plasticity in the olfactory system referred to as induction. In this process, subjects unable to smell a particular odor, or unable to differentiate similar odors, gain these abilities through mere exposure to the odor(s) over time without the need for attention or feedback (reward or punishment). However, few studies of induction have rigorously documented changes in olfactory threshold for the odor(s) used for "enrichment." We trained 36 CD-1 mice in an operant-olfactometer (go/no go task) to discriminate a mixture of stereoisomers from a lone stereoisomer using two enantiomeric pairs: limonene and carvone. We also measured each subject's ability to detect one of the stereoisomers of each odor. In order to assess the effect of odor enrichment on enantiomer discrimination and detection, mice were exposed to both stereoisomers of limonene or carvone for 2 to 12 weeks. Enrichment was effected by adulterating a subject's food (passive enrichment) with one pair of enantiomers or by exposing a subject to the enantiomers in daily operant discrimination testing (active enrichment). We found that neither form of enrichment altered discrimination nor detection. And this result pertained using either within-subject or between-subject experimental designs. Unexpectedly, our threshold measurements were among the lowest ever recorded for any species, which we attributed to the relatively greater amount of practice (task replication) we allowed our mice compared to other reports. Interestingly, discrimination thresholds were no greater (limonene) or only modestly greater (carvone) from detection thresholds suggesting chiral-specific olfactory receptors determine thresholds for these compounds. The super-sensitivity of mice, shown in this study, to the limonene and carvone enantiomers, compared to the much lesser acuity of humans for these compounds, reported elsewhere, may resolve the mystery of why the former group with four-fold more olfactory receptors have tended, in previous studies, to have similar thresholds to the latter group. Finally, our results are consistent with the conclusion that supervised-perceptual learning i.e. that involving repeated feedback for correct and incorrect decisions, rather than induction, is the form of plasticity that allows animals to fully realize the capabilities of their olfactory system.
Assuntos
Odorantes/análise , Olfatometria , Percepção Olfatória/efeitos dos fármacos , Animais , Limoneno/química , Limoneno/farmacologia , Camundongos , VolatilizaçãoRESUMO
Environmental endocrine-disrupting chemicals (EDCs) disrupt hormone-dependent biological processes. We examined how prenatal exposure to EDCs act in a sex-specific manner to disrupt social and olfactory behaviors in adulthood and underlying neurobiological mechanisms. Pregnant rat dams were injected daily from embryonic day 8 to 18 with 1 mg/kg Aroclor 1221 (A1221), 1 mg/kg vinclozolin, or the vehicle (6% DMSO in sesame oil). A1221 is a mixture of polychlorinated biphenyls (weakly estrogenic) while vinclozolin is a fungicide (anti-androgenic). Adult male offspring exposed to A1221 or vinclozolin, and females exposed to A1221, had impaired mate preference behavior when given a choice between 2 opposite-sex rats that differed by hormone status. A similar pattern of impairment was observed in an odor preference test for urine-soaked filter paper from the same rat groups. A habituation/dishabituation test revealed that all rats had normal odor discrimination ability. Because of the importance of the ventrolateral portion of the ventromedial nucleus (VMNvl) in mate choice, expression of the immediate early gene product Fos was measured, along with its co-expression in estrogen receptor alpha (ERα) cells. A1221 females with impaired mate and odor preference behavior also had increased neuronal activation in the VMNvl, although not specific to ERα-expressing neurons. Interestingly, males exposed to EDCs had normal Fos expression in this region, suggesting that other neurons and/or brain regions mediate these effects. The high conservation of hormonal, olfactory, and behavioral traits necessary for reproductive success means that EDC contamination and its ability to alter these traits has widespread effects on wildlife and humans.
Assuntos
Disruptores Endócrinos/farmacologia , Percepção Olfatória/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Comportamento Sexual Animal/efeitos dos fármacos , Núcleo Hipotalâmico Ventromedial/efeitos dos fármacos , Animais , Comportamento de Escolha/efeitos dos fármacos , Feminino , Masculino , Odorantes , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/psicologia , Ratos , Ratos Sprague-Dawley , Reprodução/efeitos dos fármacos , Núcleo Hipotalâmico Ventromedial/fisiopatologiaRESUMO
Building on a growing body of research suggesting that political attitudes are part of broader individual and biological orientations, we test whether the detection of the hormone androstenone is predictive of political attitudes. The particular social chemical analyzed in this study is androstenone, a nonandrogenic steroid found in the sweat and saliva of many mammals, including humans. A primary reason for scholarly interest in odor detection is that it varies so dramatically from person to person. Using participants' self-reported perceptions of androstenone intensity, together with a battery of survey items testing social and political preferences and orientations, this research supports the idea that perceptions of androstenone intensity relate to political orientations-most notably, preferences for social order-lending further support to theories positing the influence of underlying biological traits on sociopolitical attitudes and behaviors.
Assuntos
Androstenos/farmacologia , Percepção Olfatória/efeitos dos fármacos , Percepção Olfatória/fisiologia , Política , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Princípios Morais , Odorantes , Inventário de Personalidade , Comportamento Sexual , Fatores Socioeconômicos , Estados UnidosRESUMO
During the initial pandemic wave of COVID-19, apart from common presenting symptoms (cough, fever, and fatigue), many countries have reported a sudden increase in the number of smell and taste dysfunction patients. Smell dysfunction has been reported in other viral infections (parainfluenza, rhinovirus, SARS, and others), but the incidence is much lower than SARS-CoV-2 infection. The pathophysiology of post-infectious olfactory loss was hypothesized that viruses may produce an inflammatory reaction of the nasal mucosa or damage the olfactory neuroepithelium directly. However, loss of smell could be presented in COVID-19 patients without other rhinologic symptoms or significant nasal inflammation. This review aims to provide a brief overview of recent evidence for epidemiology, pathological mechanisms for the smell, and taste dysfunction in SARS-CoV-2 infected patients. Furthermore, prognosis and treatments are reviewed with scanty evidence. We also discuss the possibility of using "smell and taste loss" as a screening tool for COVID-19 and treatment options in the post-SARS-CoV-2 infectious olfactory loss.
Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/fisiopatologia , Transtornos do Olfato/epidemiologia , Transtornos do Olfato/fisiopatologia , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/fisiopatologia , Corticosteroides/uso terapêutico , Antivirais/uso terapêutico , COVID-19 , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/tratamento farmacológico , Humanos , Incidência , Transtornos do Olfato/diagnóstico , Transtornos do Olfato/tratamento farmacológico , Mucosa Olfatória/efeitos dos fármacos , Mucosa Olfatória/fisiopatologia , Mucosa Olfatória/virologia , Percepção Olfatória/efeitos dos fármacos , Pneumonia Viral/diagnóstico , Pneumonia Viral/tratamento farmacológico , Guias de Prática Clínica como Assunto , Prognóstico , Quinoxalinas/uso terapêutico , Remissão Espontânea , SARS-CoV-2 , Percepção Gustatória/efeitos dos fármacos , Vitamina A/uso terapêuticoRESUMO
Many chemical substances are detectable in house dust, and they are consequently taken into our bodies via the mouth and nose. Triphenyl phosphate (TPhP), a flame retardant that has an estrogen-like effect in vitro, is present in house dust at high concentrations. Estrogen exposure during development has significant influences on reproductive behavior in rodents, and its effects persist until maturity. In the present study, we investigated the effect of early life exposure to TPhP on the reproductive behavior of female rats. Oral treatment with TPhP (25 or 250 mg/kg), ethinyl estradiol (EE; 15 µg/kg) as a positive control, or sesame oil as a negative control, were given to female rats (from birth to 28 days of age). The 8-week-old rats were bilaterally ovariectomized. At 12-15 weeks of age, the rats were subjected to odor preference and sexual behavior tests. In the odor preference test, the oil group showed significantly higher preference for male odor than female odor, but the low-dose TPhP treatment group lost the preference for male odor, indicating a possible outcome of early life TPhP exposure on sexual recognition. In the sexual behavior test, both the EE and TPhP treatment groups displayed significantly less proceptive behavior. These results suggest that early life exposure to TPhP disturbs the normal sexual behavior of female rats.
Assuntos
Disruptores Endócrinos/toxicidade , Retardadores de Chama/toxicidade , Odorantes , Percepção Olfatória/efeitos dos fármacos , Organofosfatos/toxicidade , Comportamento Sexual Animal/efeitos dos fármacos , Olfato/efeitos dos fármacos , Fatores Etários , Animais , Etinilestradiol/toxicidade , Feminino , Masculino , Preferência de Acasalamento Animal/efeitos dos fármacos , Ratos Wistar , Fatores SexuaisRESUMO
BACKGROUND: Anticholinergic challenge can induce odor identification impairment that indicates Alzheimer's disease (AD) pathology, and short-term change in odor identification impairment with cholinesterase inhibitor (CheI) treatment may predict longer term cognitive outcomes. OBJECTIVE: In patients with mild cognitive impairment (MCI) treated prospectively with donepezil, a CheI, for 52 weeks, to determine if 1) acute decline in odor identification ability with anticholinergic challenge can predict cognitive improvement, and 2) change in odor identification over 8 weeks can predict cognitive improvement. METHODS: MCI was diagnosed clinically without AD biomarkers. At baseline, the University of Pennsylvania Smell identification Test (UPSIT) was administered before and after an anticholinergic atropine nasal spray challenge. Donepezil was started at 5âmg daily, increased to 10âmg daily if tolerated, and this dose was maintained for 52 weeks. Main outcomes were ADAS-Cog total score and Selective Reminding Test (SRT) total immediate recall score measured at baseline, 26 and 52 weeks. RESULTS: In 100 study participants, mean age 70.14 (SD 9.35) years, atropine-induced decrease in UPSIT score at baseline was not associated with change in ADAS-Cog or SRT scores over 52 weeks. Change in UPSIT score from 0 to 8 weeks did not show a significant association with change in the ADAS-Cog or SRT measures over 52 weeks. CONCLUSION: These negative findings in a relatively large sample of patients with MCI did not replicate results in much smaller samples. Change in odor identification with anticholinergic challenge, and over 8 weeks, may not be useful predictors of cognitive improvement with CheI in patients with MCI.
Assuntos
Inibidores da Colinesterase/administração & dosagem , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/tratamento farmacológico , Donepezila/administração & dosagem , Percepção Olfatória/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Olfato/efeitos dos fármacosRESUMO
We aimed to investigate the changes of olfaction of major depressive disorder (MDD) before and after medical treatment, and to preliminarily scrutinize the association between the olfactory function and the severity of depressive symptoms, response inhibition, and emotional responding. Forty-eight medicine-naïve MDD patients plus 33 healthy controls (HC) matched on gender, ages, and level of education, were recruited in the test group. The Chinese Smell Identification Test (CSIT), Self-reported Olfactory Scale (SROS), 17-item Hamilton Depression Rating Scale (HAMD-17), Hamilton Anxiety Rating Scale (HAMA), and mean reaction time/accuracy rate (ΔMRT) of emotional Stroop test were measured. The patients were assessed before the treatment (baseline) and 3 months after the treatment (follow-up). The data at the baseline level were measured then associated using multiple linear regression stepwise analysis. The MDD patients had lower scores of the CSIT and SROS and longer ΔMRT at baseline level compared to HC while the ΔMRT of MDD patients remained longer after 3-month treatment (p's < 0.05). At the baseline level, the regression equation including age and ΔMRT of negative word-color congruent (NEG-C), was finally observed as follows: y(CSIT) = 10.676-0.063 × 1-0.002 × 2, [x1 = the age(y), x2 = the NEG-C (ms)]. The olfactory function of MDD appears to be correlated negatively with the age and the ΔMRT of negative stimuli before treatment. After the remission of MDD, the olfactory dysfunction was improved, which might be regarded as a responding phenotype of brain function of MDD rather than the emotional responding.
Assuntos
Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/complicações , Inibição Psicológica , Transtornos do Olfato/etiologia , Percepção Olfatória/fisiologia , Adulto , Fatores Etários , Antidepressivos/farmacologia , Estudos de Casos e Controles , Cognição/efeitos dos fármacos , Cognição/fisiologia , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Emoções/efeitos dos fármacos , Emoções/fisiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Olfato/diagnóstico , Transtornos do Olfato/tratamento farmacológico , Transtornos do Olfato/fisiopatologia , Córtex Olfatório/efeitos dos fármacos , Córtex Olfatório/fisiopatologia , Percepção Olfatória/efeitos dos fármacos , Tempo de Reação/fisiologia , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto JovemRESUMO
Functional magnetic resonance imaging (fMRI) is a valuable tool for studying neural activations in the central nervous system of animals due to its wide spatial coverage and non-invasive nature. However, the advantages of fMRI have not been fully realized in functional studies in mice, especially in the olfactory system, possibly due to the lack of suitable anesthesia protocols with spontaneous breathing. Since mice are widely used in biomedical research, it is desirable to evaluate different anesthesia protocols for olfactory fMRI studies in mice. Dexmedetomidine (DEX) as a sedative/anesthetic has been introduced to fMRI studies in mice, but it has a limited anesthesia duration. To extend the anesthesia duration, DEX has been combined with a low dose of isoflurane (ISO) or ketamine (KET) in previous functional studies in mice. In this report, olfactory fMRI studies were performed under three anesthesia protocols (DEX alone, DEX/ISO, and DEX/KET) in three different groups of mice. Isoamyl-acetate was used as an odorant, and the odorant-induced neural activations were measured by blood oxygenation-level dependent (BOLD) fMRI. BOLD fMRI responses were observed in the olfactory bulb (OB), anterior olfactory nuclei (AON), and piriform cortex (Pir). Interestingly, BOLD fMRI activations were also observed in the prefrontal cortical region (PFC), which are most likely caused by the draining vein effect. The response in the OB showed no adaptation to either repeated odor stimulations or continuous odor exposure, but the response in the Pir showed adaptation during the continuous odor exposure. The data also shows that ISO suppresses the olfactory response in the OB and AON, while KET enhances the olfactory response in the Pir. Thus, DEX/KET should be an attractive anesthesia for olfactory fMRI in mice.