Effects Of Olfactory Stimulation Research Articles

Effect of olfactory stimulation from aromatherapy on the autonomic nervous activity during aerobic exercises

Variations in the autonomic nervous system activity during exercise therapy in patients with cardiovascular diseases may lead to adverse events. Aromatherapy may reduce these adverse events by enhancing parasympathetic nervous activity (PNA). However, the effects of aromatherapy during exercise remain relatively unknown. This study aimed to evaluate the effect of aromatherapy on autonomic nervous activity during exercise and recovery. This randomized crossover study included 20 healthy men subjected to both aroma and placebo conditions which involved rest and moderate-intensity aerobic exercise on a cycle ergometer, followed by recovery. Blood pressure, heart rate variability indices, and SpO2 were measured during the rest, exercise, and recovery phases. Moreover, aroma preferences and emotional changes in response to the aroma were assessed. Under the placebo condition, high frequency (HF), root mean square of successive differences indices, and heart rate showed delayed recovery (P < 0.05). Furthermore, a moderate positive correlation was identified between aroma preference, pleasant emotions induced by aromatherapy, and the HF index (P < 0.05). These results indicate that aromatherapy facilitates the recovery of PNA after exercise. Furthermore, these effects were more pronounced among individuals who exhibited a stronger preference for and more positive emotions toward aromas.

The effects of olfactory stimulation on the behaviour of captive slender lorises (Loris lydekkerianus)

Studies on primate sense of smell are scarce, even though odours represent the main communicative channel for many nocturnal primates such as gray slender lorises (Loris lydekkerianus). Here, we investigate the influence of natural odours on communicative and social behaviours on a group of slender lorises housed at the Frankfurt Zoo. Previously collected chemical marks from unknown conspecifics, urine from a natural predator (rusty-spotted cats) and a control setup were introduced in random order to the group enclosure. We recorded chemical communication behaviours, such as marking and sniffing, social behaviours and general activities. Using generalized linear mixed-effect models, we found that the odours did not have an effect on marking, but on sniffing behaviours of the animals. Conspecific odours decreased the sniffing frequencies of the animals (especially shortly after introduction). When predator odours were introduced, sniffing increased when compared to treatments with conspecific odours, but not in comparison to control treatments. The frequency of social behaviours, feeding and self-grooming did not change in response to predator or conspecific odours. Despite some limitations to our study, the data show a trend that natural odours may trigger some interest in group-kept slender lorises, and further examination of other novel odours may be worth studying (e.g. for potential chemical enrichment in zoos).

Effect of Olfactory Stimulation with Breast Milk on Pain Responses to Heel Stick in Premature Infants: A Randomized Controlled Trial.

Purpose: This study aimed to evaluate the effect of breast milk olfactory stimulation on pain response in premature infants during heel stick tests. Methods: A quasi-experimental randomized controlled trial was conducted in the neonatal intensive care unit of a tertiary-level hospital in Seoul, Korea. A breast milk group was provided olfactory stimulation with breast milk 30 seconds before the start of heel stick sampling, and a control group underwent heel stick sampling without olfactory stimulation. To evaluate infants' pain response, the heel stick procedure was video recorded, and pain response was assessed separately by two blinded research assistants using the Premature Infant Pain Scale (PIPS) through behavioral response, heart rate on physiological monitoring, and blood oxygen saturation on pulse oximetry through the video recording. Results: Forty-eight premature infants (gestational age, within 28-37 weeks, n = 24; control) were included in this study. The pain scores of the breast milk group were significantly lower than those of the control group (z = -2.04, p = 0.021). Conclusion: Breast milk odor may reduce pain in premature infants during heel stick tests.

Effect of Olfactory Stimulation with Vanilla Odor on Degree of Gastric Myoelectrical Activity

Olfactory stimulation elicits various physiological responses. However, few reports exist on the changes in gastric motility during olfactory stimulation in humans. In this regard, we carried out electrogastrography (EGG) to non-invasively measure the gastric myoelectrical activity, which regulates gastric motility. Moreover, subjective sensory evaluation was performed to determine which characteristics of vanilla odor at two different concentrations affect the myoelectrical activity. The participants consisted of eight healthy young males. EGG and electrocardiography (ECG) recordings were obtained approximately 20 min prior to and during olfactory stimulation. Autonomic nervous system activity was evaluated in terms of heart rate variability (HRV) and mean heart rate (HR) from ECG signals. EGG signals were analyzed by spectral analysis. In addition, the translation error was estimated by the Wayland algorithm. Sensory evaluation was performed using the Visual Analog Scale (VAS). There were no significant differences in HRV and HR values and results of spectral analyses of EGG signals in all sample presentations. The translation error of EGG signals and the rating of perceived odor intensity significantly increased in a concentration-dependent manner. There was a strong positive correlation between translation error and odor intensity. The correlation found between translation error and odor intensity suggests that the higher the vanilla odor intensity was perceived, the greater the randomness of EGG signals was. Our results suggest that the application of the Wayland algorithm to EGG signals can be used as an objective indicator in odor evaluation.

Effects of Olfactory Stimulation on Swallowing Function in Taiwanese Older Adults.

This pretest-posttest pilot study was to examine the effects of how olfactory stimulation (OS) influenced swallowing function in older adults. Forty-four community-dwelling older residents (24 OS & 20 control) from southern Taiwan were recruited. Participants in the intervention group administered pre-meal OS using odor and flavor inhalation. The study found that physiological responses for different food textures significantly differed between groups at post-test (p ≤ .02). Within the experimental group, swallowing function, and individual satisfaction showed significant differences before and after the odor inhalation over time (p < .01, = 0.16–0.33). An individual’s satisfaction to their own swallowing capacity was largely enhanced by the significant interaction between time and group (F[1, 42] = 11.34, p = .002, = 0.21), but not for physiological response to OS and swallowing function. The results suggest OS may be advantageous to improving physiological response to OS, swallowing function and satisfaction with swallowing capacity in older adults.

후각자극이 만성 뇌졸중 환자의 균형, 경직 및 삶의 질에 미치는 효과

본 연구는 만성 뇌졸중 환자를 대상으로 2주간 후각 자극이 균형, 경직 및 삶의 질에 미치는 효과를 규명하기 위하여 실시되었다. 단일맹검 및 사전 무작위 임상시험으로 진행되었으며, 21명의 만성 뇌줄중 환자는 무작위로 후각자극군(n=10)과 속임 후각자극군(n=11)으로 배정되었다. 후각자극 군은 라벤더 오일을 2주간 주 5회, 총 10회 시행하였고, 속임 후각자극 군은 물을 적용하였다. 경직은 Composite Spasticity Score (CSS)를 사용하여 측정하였고, 정적균형은 힘판(force plate), 동적균형은 Timed up and go test(TUG), 삶의 질은 Short-Form 36 items(SF-36)를 사용하였다. 훈련 후 후각자극 군이 속임 후각자극 군에 비해 정적균형이 유의하게 개선되었으며(p.05), 경직과 동적균형은 집단 간 유의한 차이가 없었다. 또한, 후각자극 군에서 SF 36의 정신적 건강요약과 총점이 속임 후각자극 군에 비해 유의하게 개선되었다. 본 연구는 후각자극이 만성 뇌졸중 환자의 정적균형과 삶의 질을 효과적으로 향상시킴을 증명하였다.

Effect of Olfactory Stimulation Mixed Carbonated Water Swallow on Suprahyoid Muscle Activity in Healthy Subjects

Effect of Olfactory Stimulation Mixed Carbonated Water Swallow on Suprahyoid Muscle Activity in Healthy Subjects

Effect of Olfactory Stimulation by L-Menthol on Laboratory-Induced Dyspnea in COPD

Inhalation of L-menthol as a transient receptor potential melastatin 8 agonist induces a cooling sensation in the airway. This cooling sensation induced through olfactory stimulation by L-menthol (OSM) alleviates dyspnea in healthy humans. Therefore, we investigated effects of OSM on the neural respiratory drive (NRD) and multidimensional aspects of dyspnea induced by inspiratory resistive loaded breathing in COPD. In total, 28 patients with COPD and 14 control participants were included in this randomized, single-blinded, placebo-controlled, crossover study. OSM was administered using an L-menthol-scented patch, whereas placebo was administered using olfactory stimulation by strawberry-scented patch: placebo (OSP). Sham condition was measured by breathing through a face mask without a OSP. Dyspnea was evoked by breathing through the inspiratory resistance of 20 or 30cm H2O/L/s and measured using the Multidimensional Dyspnea Profile. NRD was estimated using the electromyogram activities of the parasternal intercostal muscles. Compared with sham and OSP, OSM did not alter the breathing pattern/timing and NRD during inspiratory resistive loading; however, it significantly alleviated the physical and mental breathing effort, air hunger, breathing discomfort, anxiety, and fear during inspiratory resistive loaded breathing in patients with COPD. However, although OSM reduced the air hunger, mental breathing effort, and unpleasantness, no significant improvement on affective dimension of dyspnea by OSM was observed in control participants. Our findings suggest that OSM activated the sense of inspiratory flow that achieved dyspnea relief in patients with COPD. UMIN Clinical Trials Registry (UMIN-CTR); No.: UMIN000033822; URL: https://www.umin.ac.jp/ctr/index.htm.

The effect of olfactory stimulation on neuronal activity in dreaming during nrem 2 stage of sleep and sensory perception during dreams

The effect of olfactory stimulation on neuronal activity in dreaming during nrem 2 stage of sleep and sensory perception during dreams

후각자극이 노인의 균형에 미치는 영향

후각자극이 노인의 균형에 미치는 영향

Impact of food odors signaling specific taste qualities and macronutrient content on saliva secretion and composition

Olfactory food cues can induce appetite for similar food products in humans. Odors may thus signal essential information about a foods’ composition such as taste or even macronutrient content and may stimulate specific physiological responses in anticipation of food intake. Several studies have shown that sensory food cues could stimulate saliva secretion. However, potential differences between food odors in their effect on saliva secretion, or the effects of olfactory stimulation on changes in saliva composition remain to be elucidated. To gain more insight, we conducted two studies to determine the influence of various odors, representing different taste qualities (study 1) and macronutrients (study 2), on salivary biomarkers. In study 1, 36 participants were randomly exposed to no-odor, non-food, and odors signaling sweet, savory, and sour taste. In study 2, 60 participants were randomly exposed to no-odor, non-food, and odors signaling carbohydrates, protein, fat, and low-calorie food. For each condition, whole-mouth saliva was collected and saliva secretion rate determined. Furthermore, we determined mouth-watering perception (subjective salivation), visco-elasticity (study 1 only), mucin concentration, α-amylase and lingual lipase activity (study 2 only). For both studies, linear mixed model analyses showed that saliva secretion rate significantly increased by food odor exposure compared to no-odor and non-food conditions. However, no changes in salivary composition were observed. These findings indicate that food odors play a crucial role in anticipatory saliva responses and can thereby affect subsequent eating behavior.

The olfactory stimulation slows down the substance clearance in the extracellular space of the hippocampus in rat brain

Accelerating the clearance of toxin in the brain extracellular space (ECS) has grown a promising strategy for treating some central nervous system diseases. As oldest sensory system, we know little about the influence of olfaction on the brain, but preclinical studies such as treatment of neurological diseases through it are in the ascendant. This makes it important to clarify the effects of olfaction on brain ECS and interstitial fluid (ISF) drainage. In this study, the effect of olfactory stimulation (eugenol, EUG) on ISF flow in hippocampus and its association with aquaporin 4 (Aqp4) had been investigated. The results show that eugenol can significantly increase the activity of hippocampal neurons, but reduce the clearance and diffusion rates of Gd-DTPA and A-594 in hippocampus. Similarly, eugenol inhalation slows down the rate of Gd-DTPA in CSF entering the hippocampus and its clearance. And knockout of Aqp4 gene aggravated these processes. In vitro results showed that after Aqp4 gene silencing, astrocytes grew slowly, with significantly decreased cells number, less nuclei, atrophied bodies and shorter processes. These results concluded that olfactory stimulation can change the ECS structure of the hippocampus, slow down the ISF drainage, and improve the function of neurons, while Aqp4 plays important roles.

The effects of olfactory stimulation on the behaviour of captive meerkats (Suricata suricatta)

Olfactory stimulation has been demonstrated to enhance welfare in a range of captive species through increasing behavioural diversity or decreasing frequencies of abnormal behaviours. Despite meerkats being commonly kept in many animal collections, research into methods of enrichment for captive meerkats is minimal and to date, the effects of olfactory stimulation on the behaviour of meerkats have not been explored. This study investigated the effects of olfactory stimulation on the behaviour of five meerkats (four females, one male; all captive-born) in response to five individual odour treatments: lavender, rosemary, catnip, prey odour and a no-odour control. Odours were presented individually on cloths in the animals’ enclosure for a period of three days per stimulus and meerkat behaviour was recorded using a scan-sampling technique. There was no significant effect of individual olfactory stimulation on the meerkats’ interaction with the cloth or general behaviour, although when odour versus no odour conditions were considered, higher levels of vigilance and eating behaviour were exhibited in the presence of olfactory stimuli. Overall, our findings suggest that olfactory stimulation in the form of odour-scented cloths does not greatly influence the behaviour of captive meerkats. However, further investigation using a larger sample size, different methods of odour presentation and more biologically relevant odours is recommended in order to fully explore the potential application of olfactory stimulation as enrichment in captive meerkats.

7.嗅覚刺激の自律神経と生理機能に与える影響( おいしさのシグナルと肥満(ダイエット)の科学)

7.嗅覚刺激の自律神経と生理機能に与える影響( おいしさのシグナルと肥満(ダイエット)の科学)

The effect of olfactory stimulation on affective valence of dreams and affective state upon waking: preliminary results of a pilot study

The effect of olfactory stimulation on affective valence of dreams and affective state upon waking: preliminary results of a pilot study

植物由来の香りの人に対する効果( エコロジカルボラタイル-生き物を結びつける目に見えない絆)

植物由来の香りの人に対する効果( エコロジカルボラタイル-生き物を結びつける目に見えない絆)

Effects of olfactory stimulation with scents of grapefruit and lavender essential oils on the skeletal muscle sympathetic nerve and muscle blood flow in rats

AbstractWe have previously observed that olfactory stimulation with scents of grapefruit and lavender oils have opposing effects on autonomic neurotransmission and physiological phenomena in rats. Since the suppression and facilitation of activity of the sympathetic nerves innervating the skeletal muscles decreases and increases the skeletal muscle blood flow (skeletal muscle‐BF), respectively, the effects of olfactory stimulation with scent of a grapefruit essential oil (SGFO) and scent of a lavender essential oil (SLVO) on skeletal muscle sympathetic nerve activity (skeletal muscle‐SNA) and skeletal muscle‐BF were examined. SGFO reduced, and SLVO elevated skeletal muscle‐SNA and skeletal muscle‐BF, respectively. Furthermore, 1) anosmic treatment with ZnSO4 eliminated the changes in skeletal muscle‐SNA due to SGFO and SLVO, 2) diphenhydramine, a histamine H1‐antagonist, eliminated the SGFO‐induced suppression of skeletal muscle‐SNA, and thioperamide, a histamine H3‐antagonist, abolished the SLVO‐induced enhancement of skeletal muscle‐SNA, and 3) butoxamine, an adrenergic β2‐antagonist, blocked the SLVO‐induced increase in skeletal muscle‐BF. These findings suggest that olfactory stimulation with SGFO reduces, and SLVO enhances, skeletal muscle‐BF via these autonomic changes. In addition, the histamine H1‐receptor was found to be involved in the SGFO‐induced suppression of skeletal muscle‐SNA, the H3‐receptor was shown to be concerned to the SLVO‐induced enhancement of skeletal muscle‐SNA, and the adrenergic β2‐receptor was indicated to be implicated in the SLVO‐induced increase in skeletal muscle‐BF via an increase in skeletal muscle‐SNA. These findings suggest that SGFO may suppress, and SLVO may enhance, the muscle recovery from muscle fatigue and the growth of muscles, via changes in autonomic neurotransmission.

The Effects of Olfactory Stimulation during REM Sleep on Dream and Physiological Activity: differential influences with odor preferences

The Effects of Olfactory Stimulation during REM Sleep on Dream and Physiological Activity: differential influences with odor preferences

Effect of olfactory stimulation using geranium essential oil on the quality of life and brain structure of women in their 40s

Effect of olfactory stimulation using geranium essential oil on the quality of life and brain structure of women in their 40s

Effects of olfactory stimulation by α-pinene on autonomic nervous activity

Effects of olfactory stimulation by α-pinene on autonomic nervous activity