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1.
Molecules ; 26(3)2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499197

RESUMO

Teas and various herbal teas are well-known beverages and are commonly consumed around the world. In this study, we focused on kuromoji tea. Kuromoji is a deciduous shrub of the Lauraceae family, and the plucked leaves and branches have been drunk as a tea in production areas for a long time. However, no studies have investigated the subjective and physiological effects of kuromoji tea. In this study, the effects of kuromoji tea were examined on the basis of the measurements of heart rate variability and cerebral blood flow, core body temperature and subjective assessments. Moreover, the results of this study showed that a pleasant subjective feeling could be obtained by sniffing the aroma of kuromoji teas, especially tea leaves. It was also found that the aroma of kuromoji teas has the potential to stimulate saliva secretion and increase subjective and physiological excitements in the oral cavity. 1,8-Cineole, linalool, terpinen-4-ol, carvone and geraniol were determined in both kuromoji leaves and branches. In this study, the beneficial effects of kuromoji teas when drunk conventionally were investigated.


Assuntos
Lindera/química , Odorantes/análise , Chás de Ervas/análise , Temperatura Corporal , Estudos Cross-Over , Cromatografia Gasosa-Espectrometria de Massas , Frequência Cardíaca , Humanos , Inalação , Japão , Masculino , Percepção Olfatória/fisiologia , Oxiemoglobinas/metabolismo , Microextração em Fase Sólida , Escala Visual Analógica , Adulto Jovem
2.
PLoS One ; 15(12): e0243535, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33320870

RESUMO

High-frequency oscillations of the frontal cortex are involved in functions of the brain that fuse processed data from different sensory modules or bind them with elements stored in the memory. These oscillations also provide inhibitory connections to neural circuits that perform lower-level processes. Deficit in the performance of these oscillations has been examined as a marker for Alzheimer's disease (AD). Additionally, the neurodegenerative processes associated with AD, such as the deposition of amyloid-beta plaques, do not occur in a spatially homogeneous fashion and progress more prominently in the medial temporal lobe in the early stages of the disease. This region of the brain contains neural circuitry involved in olfactory perception. Several studies have suggested that olfactory deficit can be used as a marker for early diagnosis of AD. A quantitative assessment of the performance of the olfactory system can hence serve as a potential biomarker for Alzheimer's disease, offering a relatively convenient and inexpensive diagnosis method. This study examines the decline in the perception of olfactory stimuli and the deficit in the performance of high-frequency frontal oscillations in response to olfactory stimulation as markers for AD. Two measurement modalities are employed for assessing the olfactory performance: 1) An interactive smell identification test is used to sample the response to a sizable variety of odorants, and 2) Electroencephalography data are collected in an olfactory perception task with a pair of selected odorants in order to assess the connectivity of frontal cortex regions. Statistical analysis methods are used to assess the significance of selected features extracted from the recorded modalities as Alzheimer's biomarkers. Olfactory decline regressed to age in both healthy and mild AD groups are evaluated, and single- and multi-modal classifiers are also developed. The novel aspects of this study include: 1) Combining EEG response to olfactory stimulation with behavioral assessment of olfactory perception as a marker of AD, 2) Identification of odorants most significantly affected in mild AD patients, 3) Identification of odorants which are still adequately perceived by mild AD patients, 4) Analysis of the decline in the spatial coherence of different oscillatory bands in response to olfactory stimulation, and 5) Being the first study to quantitatively assess the performance of olfactory decline due to aging and AD in the Iranian population.


Assuntos
Doença de Alzheimer/diagnóstico , Lobo Frontal/patologia , Percepção Olfatória/fisiologia , Idoso , Doença de Alzheimer/fisiopatologia , Biomarcadores/metabolismo , Encéfalo/patologia , Córtex Cerebral/patologia , Diagnóstico Precoce , Eletroencefalografia/métodos , Feminino , Lobo Frontal/metabolismo , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Odorantes , Olfato/fisiologia , Lobo Temporal/patologia
3.
Nat Commun ; 11(1): 3845, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737295

RESUMO

Many experimental studies suggest that animals can rapidly learn to identify odors and predict the rewards associated with them. However, the underlying plasticity mechanism remains elusive. In particular, it is not clear how olfactory circuits achieve rapid, data efficient learning with local synaptic plasticity. Here, we formulate olfactory learning as a Bayesian optimization process, then map the learning rules into a computational model of the mammalian olfactory circuit. The model is capable of odor identification from a small number of observations, while reproducing cellular plasticity commonly observed during development. We extend the framework to reward-based learning, and show that the circuit is able to rapidly learn odor-reward association with a plausible neural architecture. These results deepen our theoretical understanding of unsupervised learning in the mammalian brain.


Assuntos
Condicionamento Clássico/fisiologia , Rede Nervosa , Plasticidade Neuronal/fisiologia , Condutos Olfatórios/fisiologia , Percepção Olfatória/fisiologia , Olfato/fisiologia , Animais , Teorema de Bayes , Simulação por Computador , Mamíferos , Neurônios/citologia , Neurônios/fisiologia , Odorantes/análise , Bulbo Olfatório/fisiologia , Recompensa
4.
PLoS One ; 15(7): e0236468, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730278

RESUMO

The affective appraisal of odors is known to depend on their intensity (I), familiarity (F), detection threshold (T), and on the baseline affective state of the observer. However, the exact nature of these relations is still largely unknown. We therefore performed an observer experiment in which participants (N = 52) smelled 40 different odors (varying widely in hedonic valence) and reported the intensity, familiarity and their affective appraisal (valence and arousal: V and A) for each odor. Also, we measured the baseline affective state (valence and arousal: BV and BA) and odor detection threshold of the participants. Analyzing the results for pleasant and unpleasant odors separately, we obtained two models through network analysis. Several relations that have previously been reported in the literature also emerge in both models (the relations between F and I, F and V, I and A; I and V, BV and T). However, there are also relations that do not emerge (between BA and V, BV and I, and T and I) or that appear with a different polarity (the relation between F and A for pleasant odors). Intensity (I) has the largest impact on the affective appraisal of unpleasant odors, while F significantly contributes to the appraisal of pleasant odors. T is only affected by BV and has no effect on other variables. This study is a first step towards an integral study of the affective appraisal of odors through network analysis. Future studies should also include other factors that are known to influence odor appraisal, such as age, gender, personality, and culture.


Assuntos
Modelos Biológicos , Redes Neurais de Computação , Odorantes/análise , Percepção Olfatória/fisiologia , Nível de Alerta , Intervalos de Confiança , Feminino , Humanos , Masculino , Estimulação Física , Adulto Jovem
5.
Nature ; 583(7815): 253-258, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32612230

RESUMO

The cortex organizes sensory information to enable discrimination and generalization1-4. As systematic representations of chemical odour space have not yet been described in the olfactory cortex, it remains unclear how odour relationships are encoded to place chemically distinct but similar odours, such as lemon and orange, into perceptual categories, such as citrus5-7. Here, by combining chemoinformatics and multiphoton imaging in the mouse, we show that both the piriform cortex and its sensory inputs from the olfactory bulb represent chemical odour relationships through correlated patterns of activity. However, cortical odour codes differ from those in the bulb: cortex more strongly clusters together representations for related odours, selectively rewrites pairwise odour relationships, and better matches odour perception. The bulb-to-cortex transformation depends on the associative network originating within the piriform cortex, and can be reshaped by passive odour experience. Thus, cortex actively builds a structured representation of chemical odour space that highlights odour relationships; this representation is similar across individuals but remains plastic, suggesting a means through which the olfactory system can assign related odour cues to common and yet personalized percepts.


Assuntos
Odorantes/análise , Córtex Olfatório/anatomia & histologia , Córtex Olfatório/fisiologia , Condutos Olfatórios , Compostos Orgânicos/análise , Compostos Orgânicos/química , Animais , Masculino , Camundongos , Bulbo Olfatório/citologia , Bulbo Olfatório/fisiologia , Córtex Olfatório/citologia , Percepção Olfatória/fisiologia , Olfato
7.
Nat Commun ; 11(1): 3350, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620767

RESUMO

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 fármacos
8.
Proc Natl Acad Sci U S A ; 117(27): 16065-16071, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571945

RESUMO

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.


Assuntos
Testes de Navegação Mental , Percepção Olfatória/fisiologia , Olfato/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Cavidade Nasal , Odorantes , Fluxo Óptico , Estimulação Luminosa , Adulto Jovem
9.
Eur Arch Otorhinolaryngol ; 277(12): 3519-3523, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32500326

RESUMO

PURPOSE: COVID-19 displays a variety of clinical manifestations; in pauci-symptomatic patients olfactory (OD) and gustatory dysfunctions (GD) may represent the first or only symptom. This topic is currently arousing great interest, and a growing number of papers are being published. Aim of this study is to investigate the timing of recovery from OD and GD in a real-life population hospitalized for COVID-19. METHODS: We followed up by a phone interview the first 100 patients discharged a month earlier from three Italian non-intensive care wards. RESULTS: All 100 patients were Caucasian, mean age was 65 years, 60% were males. Forty-two patients (mean age 63 years) experienced subjective chemosensory dysfunctions (29 OD and 41 GD): the male/female ratio was 2:1; 83% reported a complete or near complete recovery at follow-up. The recovery rate was not significantly different between males and females. The mean duration of OD and GD was 18 and 16 days, respectively. The mean recovery time from OD or GD resulted significantly longer for females than for males (26 vs 14 days, P = 0.009). Among the 42 symptomatic, the mean age of males was significantly higher than that of females (66 vs 57 years, P = 0.04), while the opposite was observed in the 58 asymptomatic patients (60 vs 73 years, P = 0.0018). CONCLUSIONS: Recovery from OD or GD was rapid, occurring within 4 weeks in most patients. Chemosensory dysfunctions in women was less frequent, but longer lasting. The value of our study is its focus on a population of hospitalized patients significantly older than those previously described, and the additional data on gender differences.


Assuntos
Ageusia/etiologia , Infecções por Coronavirus/diagnóstico , Coronavirus/isolamento & purificação , Transtornos do Olfato/diagnóstico , Transtornos do Olfato/etiologia , Pneumonia Viral/diagnóstico , Distúrbios do Paladar/etiologia , Percepção Gustatória/fisiologia , Idoso , Ageusia/epidemiologia , Betacoronavirus , Infecções por Coronavirus/complicações , Infecções por Coronavirus/epidemiologia , Feminino , Seguimentos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Transtornos do Olfato/epidemiologia , Percepção Olfatória/fisiologia , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/epidemiologia , Recuperação de Função Fisiológica , Fatores Sexuais , Olfato , Avaliação de Sintomas/métodos , Distúrbios do Paladar/epidemiologia
10.
Am J Rhinol Allergy ; 34(5): 686-693, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32527141

RESUMO

BACKGROUND: Covid-19 is defined by an association of multiple symptoms, including frequently reported olfactory and gustatory disorders. OBJECTIVE: The main purpose of this study was to analyze the prevalence of these neurosensory impairments in patients with Covid-19, and to assess short-term recovery. METHODS: We performed a multicenter case series study during the Covid-19 epidemic. All patients presenting a RT-PCR-confirmed SARS-CoV-2 infection were included, whether hospitalized or treated at home. To analyze the prevalence and features of olfactory and gustatory dysfunctions, a phone interview was conducted 5 days after the positive PCR result. The questionnaire was submitted again 10 days later to patients having reported olfactory and gustatory disorders, in order to assess their recovery. RESULTS: 115 patients were included in our study. 81 patients (70%) reported olfactory and gustatory disorders without nasal obstruction or rhinorrhea. These impairments were more frequently reported in the female population, young people, and house-bound patients with mild symptomatic forms. Short-term recovery assessed at Day 15 was complete for 64% of the patients, and incomplete in 33%. Median recovery time was 15 days (4-27 days) after olfactory or gustatory symptom onset. CONCLUSION: Olfactory and gustatory dysfunctions related to Covid-19 are frequently reported and prevalent in mild symptomatic forms of the disease. Recovery in most cases seems rapid and complete.


Assuntos
Betacoronavirus , Infecções por Coronavirus/complicações , Transtornos do Olfato/fisiopatologia , Percepção Olfatória/fisiologia , Pneumonia Viral/complicações , Recuperação de Função Fisiológica , Distúrbios do Paladar/fisiopatologia , Percepção Gustatória/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Coronavirus/fisiopatologia , Feminino , Seguimentos , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Olfato/etiologia , Pandemias , Pneumonia Viral/fisiopatologia , Prevalência , Estudos Prospectivos , Distúrbios do Paladar/epidemiologia , Distúrbios do Paladar/etiologia , Adulto Jovem
11.
Neuron ; 107(1): 173-184.e6, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32359400

RESUMO

Animals must discern important stimuli and place them onto their cognitive map of their environment. The neocortex conveys general representations of sensory events to the hippocampus, and the hippocampus is thought to classify and sharpen the distinctions between these events. We recorded populations of dentate gyrus granule cells (DG GCs) and lateral entorhinal cortex (LEC) neurons across days to understand how sensory representations are modified by experience. We found representations of odors in DG GCs that required synaptic input from the LEC. Odor classification accuracy in DG GCs correlated with future behavioral discrimination. In associative learning, DG GCs, more so than LEC neurons, changed their responses to odor stimuli, increasing the distance in neural representations between stimuli, responding more to the conditioned and less to the unconditioned odorant. Thus, with learning, DG GCs amplify the decodability of cortical representations of important stimuli, which may facilitate information storage to guide behavior.


Assuntos
Aprendizagem por Associação/fisiologia , Giro Denteado/fisiologia , Neurônios/fisiologia , Percepção Olfatória/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
12.
PLoS Biol ; 18(5): e3000724, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453719

RESUMO

Anticipating an odor improves detection and perception, yet the underlying neural mechanisms of olfactory anticipation are not well understood. In this study, we used human intracranial electroencephalography (iEEG) to show that anticipation resets the phase of delta oscillations in piriform cortex prior to odor arrival. Anticipatory phase reset correlates with ensuing odor-evoked theta power and improvements in perceptual accuracy. These effects were consistently present in each individual subject and were not driven by potential confounds of pre-inhale motor preparation or power changes. Together, these findings suggest that states of anticipation enhance olfactory perception through phase resetting of delta oscillations in piriform cortex.


Assuntos
Antecipação Psicológica/fisiologia , Percepção Olfatória/fisiologia , Córtex Piriforme/fisiologia , Adolescente , Adulto , Relógios Biológicos , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Nature ; 581(7809): 428-433, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32461641

RESUMO

After severe brain injury, it can be difficult to determine the state of consciousness of a patient, to determine whether the patient is unresponsive or perhaps minimally conscious1, and to predict whether they will recover. These diagnoses and prognoses are crucial, as they determine therapeutic strategies such as pain management, and can underlie end-of-life decisions2,3. Nevertheless, there is an error rate of up to 40% in determining the state of consciousness in patients with brain injuries4,5. Olfaction relies on brain structures that are involved in the basic mechanisms of arousal6, and we therefore hypothesized that it may serve as a biomarker for consciousness7. Here we use a non-verbal non-task-dependent measure known as the sniff response8-11 to determine consciousness in patients with brain injuries. By measuring odorant-dependent sniffing, we gain a sensitive measure of olfactory function10-15. We measured the sniff response repeatedly over time in patients with severe brain injuries and found that sniff responses significantly discriminated between unresponsive and minimally conscious states at the group level. Notably, at the single-patient level, if an unresponsive patient had a sniff response, this assured future regaining of consciousness. In addition, olfactory sniff responses were associated with long-term survival rates. These results highlight the importance of olfaction in human brain function, and provide an accessible tool that signals consciousness and recovery in patients with brain injuries.


Assuntos
Lesões Encefálicas/diagnóstico , Lesões Encefálicas/fisiopatologia , Estado de Consciência/fisiologia , Percepção Olfatória/fisiologia , Estado Vegetativo Persistente/diagnóstico , Estado Vegetativo Persistente/fisiopatologia , Olfato/fisiologia , Adulto , Nível de Alerta , Erros de Diagnóstico/prevenção & controle , Feminino , Humanos , Masculino , Odorantes/análise , Prognóstico , Recuperação de Função Fisiológica/fisiologia , Sensibilidade e Especificidade , Análise de Sobrevida
14.
PLoS One ; 15(4): e0231720, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320406

RESUMO

Many subjects with neuropathologically-confirmed dementia with Lewy bodies (DLB) are never diagnosed during life, instead being categorized as Alzheimer's disease dementia (ADD) or unspecified dementia. Unrecognized DLB therefore is a critical impediment to clinical studies and treatment trials of both ADD and DLB. There are studies that suggest that olfactory function tests may be able to distinguish DLB from ADD, but few of these had neuropathological confirmation of diagnosis. We compared University of Pennsylvania Smell Identification Test (UPSIT) results in 257 subjects that went on to autopsy and neuropathological examination. Consensus clinicopathological diagnostic criteria were used to define ADD and DLB, as well as Parkinson's disease with dementia (PDD), with (PDD+AD) or without (PDD-AD) concurrent AD; a group with ADD and Lewy body disease (LBD) not meeting criteria for DLB (ADLB) and a clinically normal control group were also included. The subjects with DLB, PDD+AD and PDD-AD all had lower (one-way ANOVA p < 0.0001, pairwise Bonferroni p < 0.05) first and mean UPSIT scores than the ADD, ADLB or control groups. For DLB subjects with first and mean UPSIT scores less than 20 and 17, respectively, Firth logistic regression analysis, adjusted for age, gender and mean MMSE score, conferred statistically significant odds ratios of 17.5 and 18.0 for the diagnosis, vs ADD. For other group comparisons (PDD+AD and PDD-AD vs ADD) and UPSIT cutoffs of 17, the same analyses resulted in odds ratios ranging from 16.3 to 31.6 (p < 0.0001). To our knowledge, this is the largest study to date comparing olfactory function in subjects with neuropathologically-confirmed LBD and ADD. Olfactory function testing may be a convenient and inexpensive strategy for enriching dementia studies or clinical trials with DLB subjects, or conversely, reducing the inclusion of DLB subjects in ADD studies or trials.


Assuntos
Doença de Alzheimer/diagnóstico , Encéfalo/patologia , Doença por Corpos de Lewy/diagnóstico , Transtornos do Olfato/diagnóstico , Percepção Olfatória/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Encéfalo/fisiologia , Diagnóstico Diferencial , Estudos de Viabilidade , Feminino , Humanos , Doença por Corpos de Lewy/patologia , Doença por Corpos de Lewy/fisiopatologia , Masculino , Transtornos do Olfato/fisiopatologia , Índice de Gravidade de Doença , Olfato
15.
Int Forum Allergy Rhinol ; 10(7): 814-820, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32271490

RESUMO

Early reports have suggested that smell loss may be an early symptom associated with the pandemic known as coronavirus disease 2019 (COVID-19). The possibility that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might cause olfactory dysfunction is certainly plausible. Patients presenting to specialized smell clinics are commonly diagnosed with upper respiratory infection (URI)-associated olfactory loss and most are presumed to be viral related. In acute phases of infection, it is common to experience some smell loss as a result of nasal inflammation, mucosal edema, and obstruction of airflow into the olfactory cleft. In most cases, these episodes of smell loss are self-limiting and coincide with resolution of URI symptoms. However, in some cases the smell loss persists for months to years and this is presumed to occur through a more direct olfactory insult by the virus. It remains too early to know whether infection with SARS-CoV-2 causes persistent olfactory dysfunction. However, given the scale of this pandemic, if SARS-CoV-2 does cause chronic olfactory loss in even a small portion of those infected, then the overall population prevalence could be quite large. This review provides a brief, practical overview of viral-associated olfactory loss, realizing that evidence related to COVID-19 will likely not be clear for some time. Our goal is to highlight the existence and importance of this condition and provide information geared for both providers and patients. Practical suggestions regarding evaluation and treatment will be provided, realizing that there may be constraints on medical resources and the nature of this pandemic remains dynamic.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/complicações , Transtornos do Olfato/etiologia , Transtornos do Olfato/virologia , Pneumonia Viral/complicações , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/fisiopatologia , Humanos , Transtornos do Olfato/fisiopatologia , Transtornos do Olfato/reabilitação , Percepção Olfatória/fisiologia , Pandemias , Pneumonia Viral/fisiopatologia , Olfato/fisiologia
16.
PLoS One ; 15(4): e0229302, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32241020

RESUMO

Multimodal signaling is nearly ubiquitous across animal taxa. While much research has focused on male signal production contributing to female mate-choice or preferences, females often give their own multimodal signals during intersexual communication events. Multimodal signal components are often classified based on whether they contain redundant information (e.g., the backup hypothesis) or non-redundant information (e.g., the multiple messages hypothesis) from the perspective of the receiver. We investigated the role of two different female vocalizations produced by the female house mouse (Mus musculus): the broadband, relatively low-frequency squeaks (broadband vocalizations or BBVs,), and the higher-frequency ultrasonic vocalizations (USVs). These female vocalizations may convey differently valenced information to the male receivers. We paired these vocalizations with and without female urine to examine the influence of combining information across multiple modalities. We found evidence that female urine and vocalizations act as non-redundant multimodal cues as males responded with different behaviors and vocalization rates depending on the female signal presented. Additionally, male mice responded with greater courtship effort to the multimodal combination of female USVs paired with female urine than any other signal combination. These results suggest that the olfactory information contained in female urine provides the context by which males can then evaluate potentially ambiguous female vocalizations.


Assuntos
Percepção Auditiva/fisiologia , Corte/psicologia , Percepção Olfatória/fisiologia , Olfato/fisiologia , Vocalização Animal/fisiologia , Animais , Copulação/fisiologia , Feminino , Masculino , Preferência de Acasalamento Animal/fisiologia , Camundongos , Camundongos Endogâmicos CBA , Ondas Ultrassônicas , Micção/fisiologia
17.
Int J Neural Syst ; 30(3): 2050011, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32116092

RESUMO

Olfactory-induced electroencephalogram (EEG) signal classification is of great significance in a variety of fields, such as disorder treatment, neuroscience research, multimedia applications and brain-computer interface. In this paper, a trapezoid difference-based electrode sequence hashing method is proposed for olfactory EEG signal classification. First, an N-layer trapezoid feature set whose size ratio of the top, bottom and height is 1:2:1 is constructed for each frequency band of each EEG sample. This construction is based on N optimized power-spectral-density features extracted from N real electrodes and N nonreal electrode's features. Subsequently, the N real electrodes' sequence (ES) codes of each layer of the constructed trapezoid feature set are obtained by arranging the feature values in ascending order. Finally, the nearest neighbor classification is used to find a class whose ES codes are the most similar to those of the testing sample. Thirteen-class olfactory EEG signals collected from 11 subjects are used to compare the classification performance of the proposed method with six traditional classification methods. The comparison shows that the proposed method gives average accuracy of 94.3%, Cohen's kappa value of 0.94, precision of 95.0%, and F1-measure of 94.6%, which are higher than those of the existing methods.


Assuntos
Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Percepção Olfatória/fisiologia , Processamento de Sinais Assistido por Computador , Adulto , Humanos
18.
Nat Commun ; 11(1): 1450, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193370

RESUMO

Olfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.


Assuntos
Comportamento Alimentar/fisiologia , Metabolismo dos Lipídeos/fisiologia , Sistemas Neurossecretores/metabolismo , Obesidade/metabolismo , Percepção Olfatória/fisiologia , Animais , Animais Geneticamente Modificados , Butanonas/química , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Odorantes , Optogenética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Neuropeptídeos/metabolismo
19.
Behav Neurosci ; 134(1): 59-68, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31904253

RESUMO

Structural modifications in the dendritic morphology of neurons occur following many forms of experience, including exposure to drugs, complex housing, and training in specific behavioral tasks. The present study examined morphological changes in orbitofrontal (OFC) and medial prefrontal cortex (mPFC) neurons of female rats following experience with a variety of social partners or nonsocial olfactory stimuli. We reasoned that experience with various social partners or olfactory stimuli, and the associated behavioral adaptations, would drive structural modifications in prefrontal cortex neurons engaged by these stimuli. Social experience was manipulated by providing rats with a novel cage-mate or housing the animal with the same cage-mate throughout the study. Similarly, olfactory experience was manipulated by introducing novel, nonsocial odors in the home cage or exposing the animals to the same home-cage odor throughout the study. Both forms of experience resulted in altered dendritic morphology in OFC neurons, whereas morphological changes in mPFC were comparatively small and limited to changes in spine density. These observations indicate that OFC and mPFC neurons respond differently to social and nonsocial olfactory stimulation in adulthood and join the growing body of data illustrating differential effects of experience on structural plasticity in OFC and mPFC. (PsycINFO Database Record (c) 2020 APA, all rights reserved).


Assuntos
Plasticidade Neuronal/fisiologia , Percepção Olfatória/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Dendritos/fisiologia , Feminino , Lobo Frontal , Relações Interpessoais , Neurônios/fisiologia , Odorantes , Ratos
20.
PLoS One ; 15(1): e0217665, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923248

RESUMO

Olfactory sense remains elusive regarding the primary reception mechanism. Some studies suggest that olfaction is a spectral sense, the olfactory event is triggered by electron transfer (ET) across the odorants at the active sites of odorant receptors (ORs). Herein we present a Donor-Bridge-Acceptor model, proposing that the ET process can be viewed as an electron hopping from the donor molecule to the odorant molecule (Bridge), then hopping off to the acceptor molecule, making the electronic state of the odorant molecule change along with vibrations (vibronic transition). The odorant specific parameter, Huang-Rhys factor can be derived from ab initio calculations, which make the simulation of ET spectra achievable. In this study, we revealed that the emission spectra (after Gaussian convolution) can be acted as odor characteristic spectra. Using the emission spectrum of ET, we were able to reasonably interpret the similar bitter-almond odors among hydrogen cyanide, benzaldehyde and nitrobenzene. In terms of isotope effects, we succeeded in explaining why subjects can easily distinguish cyclopentadecanone from its fully deuterated analogue cyclopentadecanone-d28 but not distinguishing acetophenone from acetophenone-d8.


Assuntos
Percepção Olfatória/genética , Neurônios Receptores Olfatórios/metabolismo , Receptores Odorantes/genética , Olfato/genética , Benzaldeídos/farmacologia , Respiração Celular/genética , Transporte de Elétrons/genética , Humanos , Cianeto de Hidrogênio/farmacologia , Isótopos/farmacologia , Nitrobenzenos/farmacologia , Odorantes/análise , Percepção Olfatória/fisiologia , Neurônios Receptores Olfatórios/química , Receptores Odorantes/metabolismo , Olfato/fisiologia , Vibração
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