Search Results (125)

The housing of laboratory rats in cages with dimensions according to international standards for research animals can hardly be regarded as a stimulating environment, even when fulfilling the minimum requirements for environmental enrichment. Little is known about whether changes in the housing situations to improve living conditions will affect the phenotypic traits of well-known models for human diseases. The obese Zucker fa/fa rat develops hyperlipidemia, hypertension, and fatty liver, and is widely used for studies on metabolic complications of obesity in humans. Young male obese Zucker fa/fa rats were housed in pairs in standard individually ventilated cages (IVCs: floor area 1500 cm² and maximum height 20 cm), or 4–6 rats were housed in a large open cage (LOC: floor area 7705 cm² and height 75 cm). The LOC provided an environment with more physical, social, auditory, visual, olfactory, and tactile stimuli compared to IVCs. The aims were to compare the development of obesity comorbidities and to assess the well-being of rats housed under different conditions. The rats housed in IVCs and the LOC had similar adiposity, blood pressure, hepatic triacylglycerol content, and similar serum concentrations of cholesterol, triacylglycerol, and alanine transaminase. IVC-housed rats showed some signs of distress, such as less interest in nest-building and signs of apathy compared to LOC-housed rats. To conclude, LOC housing did not affect the typical phenotype of obese Zucker fa/fa rats but did improve the welfare of these rats. Full article

Background/Objectives: Human milk provides essential nutrients and immune factors with beneficial impact on term, but especially preterm infants’ development. Therefore, this study focuses on the quantification of differences in the peptidome composition of breast milk from mothers of preterm and term infants, keeping in mind that this could reflect different biological needs of these infants or indicate nutritional gaps for healthy development. Methods: In a prospective observational study, breast milk samples were collected from 10 mothers of preterm infants (29–36 weeks gestational age,) and 13 mothers of term infants (37–41 weeks) at day 4 to 6 postnatally. A non-targeted tandem mass spectrometry approach was employed to analyze the milk peptidome. Results: In total, 4570 peptides were quantified. Adjusting the results for maternal age, weight, and height revealed a significant difference for 130 peptides derived from 19 different proteins between preterm and term milk. Proteins comprised high abundant proteins (e.g., α_S1-casein, κ- casein, or ß-casein), but also proteins that are less prominent in milk but of high functional importance (e.g., Hypoxia-inducible factor 1-alpha, Olfactory receptor 4M1). The differentially abundant peptides included peptides derived from ß-casein, which have already been described as being involved in antimicrobial functions as well as proliferation stimulating. For another 32 peptides, bioactivity was predicted. Conclusions: The current study provides a comprehensive overview on the differences in the milk peptidome at different gestational ages independent from common maternal phenotypes and improved the database for future peptide functionality studies. Full article

Forty per cent of major depression patients are resistant to antidepressant medication. Thus, it is necessary to search for alternative treatments. Melatonin (N-acetyl-5-hydroxytryptamine) enhances neurogenesis and neuronal survival in the adult mouse hippocampal dentate gyrus. Additionally, melatonin stimulates the activity of Ca²⁺/Calmodulin-dependent Kinase II (CaMKII), promoting dendrite formation and neurogenic processes in human olfactory neuronal precursors and rat organotypic cultures. Similarly, ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, modulates CaMKII activity. Importantly, co-treatment of low doses of ketamine (10⁻⁷ M) in combination with melatonin (10⁻⁷ M) produces additive effects on neurogenic responses in olfactory neuronal precursors. Importantly, enhanced neurogenic responses are produced by conventional antidepressants like ISSRs. The goal of this study was to investigate whether hippocampal CaMKII participates in the signaling pathway elicited by combining doses of melatonin with ketamine acutely administered to mice, 30 min before being subjected to the forced swimming test. The results showed that melatonin, in conjunction with ketamine, significantly enhances CaMKII activation and changes its subcellular distribution in the dentate gyrus of the hippocampus. Remarkably, melatonin causes nuclear translocation of the active form of CaMKII. Luzindole, a non-selective MT₁ and MT₂ receptor antagonist, abolished these effects, suggesting that CaMKII is downstream of the melatonin receptor pathway that causes the antidepressant-like effects. These findings provide molecular insights into the combined effects of melatonin and ketamine on neuronal plasticity-related signaling pathways and pave the way for combating depression using combination therapy. Full article

Environmental enrichment is essential for promoting species-specific behaviors and enhancing the welfare of zoo-housed animals. This study examined the behavioral responses of two juvenile male binturongs (Arctictis binturong) at the Minnesota Zoo to three enrichment stimuli: lavender oil (olfactory), thawed fish (olfactory and dietary), and hard-boiled egg (olfactory and dietary). Their behaviors were recorded using scan sampling before and after enrichment exposure, focusing on locomotion, foraging, resting, and visitor visibility. Food-based enrichments, particularly the hard-boiled egg, significantly increased foraging behavior, while lavender oil and thawed fish produced minimal behavioral changes. Locomotion and visibility remained stable across the conditions, although a slight increase in resting was observed with lavender oil. No evidence of scent-marking disruption was noted, and individual differences appeared to influence inactivity levels. These findings highlight the potential of biologically relevant, food-based enrichment to stimulate natural behaviors in binturongs and emphasize the importance of species-specific enrichment strategies. Future research should explore a broader range of olfactory cues, assess long-term behavioral responses, and incorporate physiological measures to further evaluate enrichment impacts on binturong welfare. Full article

Araucaria araucana is one of the longest-living Chilean trees. Recently, Araucaria Leaf Damage disease, which causes damage to branches and crowns, was detected. Sinophloeus porteri, a bark beetle affecting A. araucana, could be associated with foliar damage. However, little is known about their ecological and chemical interactions. This study examined the olfactory response of S. porteri to volatiles emitted from A. araucana. Branches and weevils were collected from a national park, and volatiles were trapped from both healthy and unhealthy branches. Thirty terpenes were identified, some of which were reported for the first time in A. araucana. Healthy branches emitted large amounts of myrcene (>360 ng g⁻¹ day⁻¹), and unhealthy branches showed high hibaene emanations (>140 ng g⁻¹ day⁻¹). Olfactory assays verified that S. porteri was attracted to the volatile blends of branches, regardless of the health condition of the branches, but preferred the blend of unhealthy branches. Moreover, myrcene was repellent to these weevils, and hibaene acted as an attractant, suggesting that A. araucana might use myrcene for defense against S. porteri, and hibaene could stimulate host selection by beetles. Full article

Background: Research suggests that periodontal disease may exacerbate symptoms of coronavirus disease (COVID-19). The etiology of this condition has been associated with cytokines such as IL-6. The inflammatory response in COVID-19 can be partially attributed to periodontopathic bacteria and their metabolites. Furthermore, the aspiration of periodontal pathogens and the stimulation of ACE2 expression may lead to an increased production of inflammatory cytokines, potentially worsening COVID-19 symptoms in patients with periodontitis. Materials and Methods: A cross-sectional study was conducted involving patients with both periodontal disease and COVID-19, patients with either condition alone, and healthy subjects. All participants underwent RT-PCR testing for SARS-CoV-2, and a self-reported periodontal disease (Self-RPD) questionnaire was administered. Saliva samples were collected to assess IL-6 levels using the ELISA technique. Results: A total of 28 patients were classified as COVID-19/Self-RPD+, 32 patients had only COVID-19, 25 were Self-RPD+ only, and 17 were healthy controls. The COVID-19/Self-RPD+ group frequently exhibited symptoms such as fever, body aches, nasal congestion, and olfactory disturbances and showed significantly higher IL-6 levels compared to the other groups. Cough with phlegm was significantly more frequent in the COVID-19-only group. Additionally, IL-6 levels in saliva were elevated in patients with nasal congestion and in those with 11 or more symptoms in the Self-RPD+ group. Full article

Microfluidic platforms have emerged as critical technologies for exploring sperm chemotaxis, providing precise gradient control, and facilitating in-depth behavioral assessment. We designed a novel, user-friendly microfluidic device that is optimized for human sperm morphology and motility. The device was validated using two well-established sperm chemoattractants, progesterone and bourgeonal, demonstrating its reliability and reproducibility. Given the key role of olfactory receptors (ORs) in mediating sperm chemotaxis, the newly developed device was employed to identify additional receptors that may contribute to sperm behavior. Using the Atlas database, we identified OR2H1 as a candidate receptor. It is enriched in testis-derived cells, particularly in early and late spermatids, and it is broadly expressed across human spermatozoa. We demonstrated that OR2H1’s ligand, methional, a sulfur-containing aldehyde naturally found in vaginal fluid and biosynthesized by Lactococcus lactis, significantly enhances sperm migration and progressive motility. Methional stimulation also triggered increased intracellular calcium levels, indicating receptor activation. Computer-assisted sperm analysis revealed that methional treatment improved sperm linearity, straightness, and wobble without affecting the average velocity, suggesting enhanced directional movement. These findings provide evidence that methional promotes sperm chemotaxis via OR2H1 and highlight the potential role of the vaginal microbiome in influencing human fertility. Full article

Background: Chemosensation in ticks opens a novel and unique field for scientific research. This study highlights ticks’ chemosensory system to comprehend its host-searching behavior and other integrated chemistry and biology involving Haller’s structure. Methodology: This study combines microanatomical, electrophysiological, and behavioral experiments to investigate the role of Haller’s organ in adult ticks in response to different classes of organic compounds. Results: We showed the microscopic anatomy of Haller’s organ in Haemaphysalis darjeeling, present at the terminal segment of the first pair of appendages. Haller’s structure serves a vital function in perceiving odor. The electrophysiological activity of adult ticks to different classes of organic compounds via electroscutumography was explored at five different concentrations: w/v 0.001, 0.01, 0.1, 1.0, and 2.0%. Among 55 organic compounds, moderate to high stimulation was recorded with pyruvate (13.28 mv at 2%), ammonia (12.26 mv at 2%), benzoic acid (1.99 mv at 0.001%), isobutyric acid (1.39 mv at 0.001%), 2,6-dichlorophenol (1.34 mv at 0.001%), p-Tolualdehyde (1.26 mv at 2%), tetradecane (1.23 mv at 2%), docosane (1.17 mv at 2%), citronellal (1.13 mv at 0.1%), isopropyl acetate (1.05 mv at 0.01%), cyclohexanol (1.03 mv at 2%), 1-octane-3-ol (1.02 mv at 2%), and 1-octanol (1.01 mv at 0.001%). Olfactometric bioassays at w/v 2.0% concentration further confirmed that ammonia, pyruvate, 1-octane-3-ol, hematin porcine, p-Tolualdehyde, methyl salicylate, uric acid, tetradecane, carbon dioxide, propanoic acid, 3-hexanol, hexanoic acid, adenine, 2,6-dichlorophenol, hexadecane, heptanoic acid, pentanoic acid, octadecane, guanine, and nonanoic acid acted as strong attractants, while citronellal, eugenol, butyric acid, geraniol, benzaldehyde, and tiglic aldehyde showed an active repellent effect against the tick species. Conclusions: This investigation provides knowledge of the olfactory sensilla of Haller’s structure as biosensors behind tick olfaction and the possibility for chemical detection of diverse attractants and repellents for future development of anti-tick compounds. Full article

Environmental enrichment is crucial to improve welfare, reduce stress, and encourage natural behaviours in dogs housed in confined environments. This study aimed to use accelerometery and machine learning to evaluate the effect of different enrichment types on dog behaviour. Three enrichments (food, olfactory, and tactile) were provided to dogs for five consecutive days, with four days between each treatment. Acceleration data were collected using a collar mounted ActiGraph^®. Nine behaviours were classified using a validated machine learning model. Behaviour and activity differed significantly among the dogs. Dogs interacted most with the food enrichment, followed by the olfactory and then tactile enrichments. The dogs were least active during the olfactory enrichment, whereas activity was relatively consistent during the food and tactile enrichments. For all enrichments, dogs exhibited the most exploratory/locomotive behaviour during the first hour of each enrichment period, but this declined over the treatment period indicating habituation. For exploratory and locomotive behaviour, food enrichment was the most stimulating for the dogs with longer daily engagement than for both olfactory and tactile enrichments. These results illustrate that accelerometery and machine learning can be used to evaluate enrichment strategies in dogs, but it is important to consider variation among dogs and habituation. Full article

The antennal sensilla serve as a crucial olfactory organ, enabling insects to detect semiochemicals and adjust their host-seeking and oviposition behaviors accordingly. Monolepta signata (Oliver) (Coleoptera: Chrysomelidae), has emerged as a significant agricultural pest that affects key economic crops such as maize and cotton. Despite the development of various control methods based on volatile stimulation, there is still limited documentation on the sensilla involved in olfaction. In this study, the ultrastructure of the sensilla, especially the olfactory sensilla on the antennae of both males and females, was investigated with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Three types of olfactory sensillum types, including trichodea, basiconica, and coeloconica, and four non-olfactory sensilla including chaetica, campaniformia, auricillica, and Böhm bristle were observed. Sensilla trichodea and basiconica on the antennae of M. signata were further classified into two subtypes according to their morphology. For the first time, the pores on the sensilla trichodea, basiconica, and coeloconica cuticular walls were observed in this species, suggesting that they are involved in semiochemical perception. This study contributes new insights into the olfactory system of M. signata, which can be integrated with other molecular, genetic, and behavioral research to establish a comprehensive understanding of its physiological functions. Full article

Emotion recognition using an odor-induced electroencephalogram (EEG) has broad applications in human-computer interaction. However, existing studies often rely on subjective self-reporting to label emotion, lacking objective verification. While the β/α ratio has been identified as a potential objective indicator of arousal in EEG spectral analysis, its value in emotion recognition remains underexplored. This study ensured the authenticity of emotions through self-reporting and EEG spectral analysis of 50 adults after inhaling sandalwood essential oil (SEO) or bergamot essential oil (BEO). Classification models were built using discriminant analysis (DA), support vector machine (SVM), and random forest (RF) algorithms to identify low or high arousal emotions. Notably, this study introduced the β/α ratio as a novel frequency domain feature to enhance model performance for the first time. Both self-reporting and EEG spectral analysis indicated that SEO promotes relaxation, whereas BEO enhances attentiveness. In model testing, incorporating the β/α ratio enhanced the performance of all models, with the accuracy of DA, SVM, and RF increasing from 70%, 75%, and 85% to 75%, 80%, and 95%, respectively. This study validated the authenticity of emotions by employing a combination of subjective and objective methods and highlighted the importance of β/α in emotion recognition along the arousal dimension. Full article

Introduction: In line with previous research conducted during chemotherapy to explore whether virtual reality (VR) can support patients’ emotional regulation, this study examines the relevance of adding olfactory reinforcement to VR sessions during breast cancer treatment. Methods: An experimental protocol assessed the impact of VR sensoriality in 50 patients over three chemotherapy sessions. Each patient experienced a 10-min immersion in a natural environment under three randomized conditions: Contemplative VR, Participatory VR, Participatory VR with olfactory reinforcement. The sense of presence measured immersion, while anxiety, depression, and emotional state were evaluated using a within-subject design to compare the effects of each VR modality. Results: A reduction in anxiety and depression was observed in patients regardless of the type of VR immersion experienced. The interactive and multimodal nature of VR may support patients in their emotional regulation. Conclusions: This study provides preliminary evidence for the usefulness of olfactory enhancement in VR during chemotherapy sessions in breast cancer patients. The multimodal potential of VR contributes to the reduction of anxiety and depression by inducing a positive emotional experience in a soothing natural environment. The reported results highlight the value of sensorimotor VR, which also stimulates the sense of smell, in improving supportive care. Full article

Background/Objectives: Olfactory dysfunction (OD) is a common symptom among people with cystic fibrosis (PwCF) and contributes to environmental safety concerns, nutritional challenges, and an overall diminished quality of life. OD is perceived to progress along the lifespan in PwCF, often due to worsening sinonasal disease. Among children with cystic fibrosis (CwCF), OD is poorly characterized as limited resources and tolerance contribute to challenges in psychophysical olfactory evaluation among pediatric populations. The Children’s Personal Significance of Olfaction (ChiPSO) questionnaire was recently proposed as a tool to assess olfaction and the importance of olfactory stimulation among children. This pilot study aimed to evaluate the utility of ChiPSO among a cohort of ethnically diverse CwCF. Methods: Individuals aged 7–17 with physician-diagnosed CF were asked to complete questionnaires, including ChiPSO and the brief questionnaire on olfactory dysfunction (bQOD-NS), prior to undergoing psychophysical olfactory evaluation with the U-Sniff Identification test. Potential associations between questionnaires and olfactory performance, pulmonary function, and demographic characteristics were evaluated using Pearson and Spearman correlations, independent-sample t-tests, Wilcoxon rank sum tests, and multiple linear regression. Results: U-Sniff Identification score positively correlated with the overall ChiPSO total score [r(13) = 0.640, p = 0.010] and its environmental subdomain score [r(13) = 0.774, p < 0.001], though not with the food subdomain [r(13) = 0.450, p = 0.093], the social subdomain [r(13) = 0.343, p = 0.2], or bQOD-NS score [r(11) = −0.125, p = 0.7]. Hispanic ethnicity is associated with ChiPSO (p = 0.041). Conclusions: In this preliminary study, olfactory importance increases with olfactory function among an ethnically diverse sample of CwCF, with a preferential influence of olfactory function on personal importance of environmental olfactory information. While these results should be interpreted with limitations imposed by the pilot nature of our sample size, our pilot data highlights associations with early adolescent development of importance of olfaction that can be disrupted in the setting of progressive disease among CwCF. Full article

Background: Pain is prevalent in almost all populations and may often hinder visual, auditory, tactile, olfactory, and taste perception as it alters brain neural processing. The quantitative methods emerging to define pain and assess its effects on neural functions and perception are important. Identifying pain biomarkers is one of the initial stages in developing such models and interventions. The existing literature has explored chronic and experimentally induced pain, leveraging electroencephalograms (EEGs) to identify biomarkers and employing various qualitative and quantitative approaches to measure pain. Objectives: This systematic review examines the methods, participant characteristics, types of pain states, associated pain biomarkers of the brain’s electrical activity, and limitations of current pain studies. The review identifies what experimental methods researchers implement to study human pain states compared to human control pain-free states, as well as the limitations in the current techniques of studying human pain states and future directions for research. Methods: The research questions were formed using the Population, Intervention, Comparison, Outcome (PICO) framework. A literature search was conducted using PubMed, PsycINFO, Embase, the Cochrane Library, IEEE Explore, Medline, Scopus, and Web of Science until December 2024, following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to obtain relevant studies. The inclusion criteria included studies that focused on pain states and EEG data reporting. The exclusion criteria included studies that used only MEG or fMRI neuroimaging techniques and those that did not focus on the evaluation or assessment of neural markers. Bias risk was determined by the Newcastle–Ottawa Scale. Target data were compared between studies to organize the findings among the reported results. Results: The initial search resulted in 592 articles. After exclusions, 24 studies were included in the review, 6 of which focused on chronic pain populations. Experimentally induced pain methods were identified as techniques that centered on tactile perception: thermal, electrical, mechanical, and chemical. Across both chronic and stimulated pain studies, pain was associated with decreased or slowing peak alpha frequency (PAF). In the chronic pain studies, beta power increases were seen with pain intensity. The functional connectivity and pain networks of chronic pain patients differ from those of healthy controls; this includes the processing of experimental pain. Reportedly small sample sizes, participant comorbidities such as neuropsychiatric disorders and peripheral nerve damage, and uncontrolled studies were the common drawbacks of the studies. Standardizing methods and establishing collaborations to collect open-access comprehensive longitudinal data were identified as necessary future directions to generalize neuro markers of pain. Conclusions: This review presents a variety of experimental setups, participant populations, pain stimulation methods, lack of standardized data analysis methods, supporting and contradicting study findings, limitations, and future directions. Comprehensive studies are needed to understand the pain and brain relationship deeper in order to confirm or disregard the existing findings and to generalize biomarkers across chronic and experimentally induced pain studies. This requires the implementation of larger, diverse cohorts in longitudinal study designs, establishment of procedural standards, and creation of repositories. Additional techniques include the utilization of machine learning and analyzing data from long-term wearable EEG systems. The review protocol is registered on INPLASY (# 202520040). Full article

Electroencephalography (EEG)-basedpersonal identification has gained significant attention, but fluctuations in emotional states often affect model accuracy. Previous studies suggest that multisensory stimuli, such as video and olfactory cues, can enhance emotional responses and improve EEG-based identification accuracy. This study proposes a novel deep learning-based model, CNN-BiLSTM-Residual Network (CBR-Net), for EEG-based identification and establishes a multisensory emotional EEG dataset with both video-only and olfactory-enhanced video stimulation. The model includes a convolutional neural network (CNN) for spatial feature extraction, Bi-LSTM for temporal modeling, residual connections, and a fully connected classification module. Experimental results show that olfactory-enhanced video stimulation significantly improves the emotional intensity of EEG signals, leading to better recognition accuracy. The CBR-Net model outperforms video-only stimulation, achieving the highest accuracy for negative emotions (96.59%), followed by neutral (94.25%) and positive emotions (95.42%). Ablation studies reveal that the Bi-LSTM module is crucial for neutral emotions, while CNN is more effective for positive emotions. Compared to traditional machine learning and existing deep learning models, CBR-Net demonstrates superior performance across all emotional states. In conclusion, CBR-Net enhances identity recognition accuracy and validates the advantages of multisensory stimuli in EEG signals. Full article