Repeated exposure to kairomone-containing coffee odor improves abnormal olfactory behaviors in heterozygous oxytocin receptor knock-in mice.

The oxytocin receptor (OXTR) knockout mouse is a model of autism spectrum disorder, characterized by abnormalities in social and olfactory behaviors and learning. Previously, we demonstrated that OXTR plays a crucial role in regulating aversive olfactory behavior to butyric acid odor. In this study, we attempted to determine whether coffee aroma affects the abnormal olfactory behavior of OXTR-Venus knock-in heterozygous mice [heterozygous OXTR (±) mice] using a set of behavioral and molecular experiments.

Application of integrative physiological approach to evaluate human physiological responses to the inhalation of essential oils of Japanese citrus fruits iyokan (Citrus iyo) and yuzu (Citrus junos).

This study investigated the effects of essential oil odors from Japanese citrus fruits, iyokan (Citrus iyo) and yuzu (Citrus junos), on human psychology and both the autonomic and central nervous systems. The inhalation of both essential oils significantly increased miosis rate and fingertip temperature and could induce parasympathetic dominance by suppressing sympathetic nerve activity. Oxyhemoglobin concentration in the prefrontal cortex increased after the inhalation of yuzu essential oil and decreased after the inhalation of iyokan essential oil.

Changes in gaseous concentration of alkylpyrazine analogs affect mouse avoidance behavior.

We developed a rapid and accurate method for quantifying gaseous phase odorants using headspace solid-phase microextraction (HS-SPME) in conjunction with GC-MS and used our system to quantify alkylpyrazine analogs in the Y-maze. Rapid extraction of volatile compounds in the vapor phase achieved accurate quantitative analysis of gaseous alkylpyrazine analogs at several locations in the Y-maze. We also used a series of three SPME fibers to quantify changes in the concentration over time.

Fucoxanthin administration delays occurrence of tumors in xenograft mice by colonospheres, with an anti-tumor predictor of glycine.

Fucoxanthin and its major metabolite, fucoxanthinol, have potent anti-cancer properties in carcinogenic model mice and against cancer cells. Evidence has accumulated regarding the diagnostic potential of biological metabolites as invasive and non-invasive obtainable approaches. We recently demonstrated that glycine was an effective predictor of the suppression of sphere formation and epithelial mesenchymal transition by fucoxanthinol in human colorectal cancer stem-like spheroids (colonospheres) under normoxia and hypoxia.

Oxytocin receptor signaling contributes to olfactory avoidance behavior induced by an unpleasant odorant.

Oxytocin (OXT) and its receptor (OXTR) regulate reproductive physiology (i.e. parturition and lactation), sociosexual behavior, learned patterns of behavior and olfactory behavior in social contexts.

Glycine and succinic acid are effective indicators of the suppression of epithelial-mesenchymal transition by fucoxanthinol in colorectal cancer stem-like cells.

Fucoxanthinol (FxOH) is a strong anticancer metabolite of fucoxanthin that accumulates in abundance in edible brown algae and promises human health benefits. FxOH has been shown to suppress tumorigenicity and sphere formation in human colorectal cancer stem cell (CCSC)-like spheroids (colonospheres, Csps). In the present study, we aimed to clarify the inhibitory activity of FxOH on epithelial-mesenchymal transition (EMT), which is essential for cancer recurrence and distant metastasis, and to identify intracellular low-molecular-weight metabolites that may be useful for evaluating the cellular effects of FxOH on CCSCs.

Glycine Is a Predictor for a Suppressive Effect of Fucoxanthinol on Colonosphere Formation Under Hypoxia.

Background/aim: Fucoxanthinol (FxOH), a metabolite of fucoxanthin, is known to inhibit tumorigenicity of human colorectal cancer stem cells (CCSCs) and their sphere formation. Hypoxic conditions and hypoxia-inducible factors (HIFs) are essential to maintain the stemness of CCSCs. We investigated effects of FxOH on sphere formation, intercellular energy metabolites in colonospheres formed from human colorectal HT-29 cells under hypoxic conditions.

Etizolam attenuates the reduction in cutaneous temperature induced in mice by exposure to synthetic predator odor.

Anxiety- and stress-related disorders can be debilitating psychiatric conditions in humans. To prevent or ameliorate these conditions, reliable animal models are needed to evaluate the effects of anxiolytic drugs. Previously, we found that a mixture of three pyrazine analogues (P-mix) that were present at high levels in wolf urine induced fear-related responses in mice, rats and deer.

Pyrazine analogues from wolf urine induced unlearned fear in rats.

Urine excreted from the common grey wolf () contains a kairomone, inducing fear-related behaviors in various mammals. Numerous fear-inducing substances activate neurons at the main and/or accessory olfactory bulb (AOB), medial and central amygdala, and hypothalamus. Our previous study showed that the mixture of pyrazine analogues (P-mix) contained in wolf urine induced avoidance and fear-related behaviors in laboratory mice and Hokkaido deer (), a species native to Japan.

Structure-Activity Relationships of Alkylpyrazine Analogs and Fear-Associated Behaviors in Mice.

Our previous studies identified alkyl pyrazine analogs in wolf urine that act as novel kairomones and induce a series of fear-associated behaviors in mice. A mixture of these alkyl pyrazines also effectively suppressed the approach of deer to a feeding area, and animals that did approach the marked area exhibited fear-associated behaviors. To investigate structure-activity relationships of alkyl pyrazines, four fear-associated behaviors - freezing, locomotion activity, odor investigation, and avoidance - were measured in experiments on female C57BL/6 J mice.

The scent of wolves: pyrazine analogs induce avoidance and vigilance behaviors in prey.

The common gray wolf (Canis lupus) is an apex predator located at the top of the food chain in the Northern Hemisphere. It preys on rodents, rabbits, ungulates, and many other kinds of mammal. However, the behavioral evidence for, and the chemical basis of, the fear-inducing impact of wolf urine on prey are unclear.

Pyrazine analogs are active components of wolf urine that induce avoidance and fear-related behaviors in deer.

Our previous studies indicated that a cocktail of pyrazine analogs, identified in wolf urine, induced avoidance and fear behaviors in mice. The effects of the pyrazine cocktail on Hokkaido deer (Cervus nippon yesoensis) were investigated in field bioassays at a deer park in Hokkaido, Japan. A set of feeding bioassay trials tested the effects of the pyrazine cocktail odor on the behavior of the deer located around a feeding area in August and September 2013.

Impaired mastication reduced newly generated neurons at the accessory olfactory bulb and pheromonal responses in mice.

Objectives: A large number of neurons are generated at the subventricular zone (SVZ) even during adulthood. In a previous study, we have shown that a reduced mastication impairs both neurogenesis in the SVZ and olfactory functions. Pheromonal signals, which are received by the vomeronasal organ, provide information about reproductive and social states.

Hard-diet feeding recovers neurogenesis in the subventricular zone and olfactory functions of mice impaired by soft-diet feeding.

The subventricular zone (SVZ) generates an immense number of neurons even during adulthood. These neurons migrate to the olfactory bulb (OB) and differentiate into granule cells and periglomerular cells. The information broadcast by general odorants is received by the olfactory sensory neurons and transmitted to the OB.

Pyrazine analogues are active components of wolf urine that induce avoidance and freezing behaviours in mice.

Background: The common grey wolf (Canis lupus) is found throughout the entire Northern hemisphere and preys on many kinds of mammals. The urine of the wolf contains a number of volatile constituents that can potentially be used for predator-prey chemosignalling. Although wolf urine is put to practical use to keep rabbits, rodents, deer and so on at bay, we are unaware of any prior behavioural studies or chemical analyses regarding the fear-inducing impact of wolf urine on laboratory mice.

Evaluation of the masking of dimethyl sulfide odors by citronellal, limonene and citral through the use of trained odor sensor mice.

Previous studies indicate that the most common result of mixing two odors is the decreased olfactory perception of one or both components in the mixture. An excellent example of this phenomenon is provided by the masking of an unpleasant odor by a pleasant odor. This study hypothesized that dimethyl sulfide (DS; a major chemical component of oral malodor) might be masked by citronellal, a monoterpene aldehyde that produces an intense lemon aroma.

Citronellal ingestion decreases the appeal of male mouse urinary pheromone for female mice.

To determine whether ingestion of citronellal decreases the attractive power of the male mouse urinary odor, female mice were used in preference tests. A series of tests revealed that the female mice preferred voided urine odors from aged mice over those from younger adult mice. However, exogenous citronellal directly inhibited the advantage of the aged males with regard to attraction.

Butylated hydroxytoluene is a ligand of urinary proteins derived from female mice.

Mice secrete substantial amounts of protein, particularly proteins called the major urinary proteins (MUPs), in urine. One function of MUPs is to sequester volatile pheromone ligands, thereby delaying their release and providing a stable long-lasting signal. Previously, only MUPs isolated from male mice have been used to identify ligands.

Alteration of mouse urinary odor by ingestion of the xenobiotic monoterpene citronellal.

Body odors provide a rich source of sensory information for other animals. There is considerable evidence to suggest that short-term fluctuations in body odor can be caused by diet; however, few, if any, previous studies have demonstrated that specific compounds can directly mask or alter mouse urinary odor when ingested and thus alter another animal's behavior. To investigate whether the ingestion of citronellal, a monoterpene aldehyde that produces an intense aroma detected by both humans and mice, can alter mouse urinary odor, mice (C57BL6J) were trained in a Y maze to discriminate between the urinary odors of male donor mice that had ingested either citronellal in aqueous solution or a control solution.

Profiles of volatiles in male rat urine: the effect of puberty on the female attraction.

Rat urine contains many volatile constituents that may be used for chemical communication. The levels of certain urinary volatiles are strongly dependent on the sex and endocrine status (e.g.

Syntheses of 2-Isopropyl-4,5-dihydrothiazole and 6-Hydroxy-6-methyl-3-heptanone, pheromone components of the male mouse, Mus musculus.

Syntheses of 2-isopropyl-4,5-dihydrothiazole and 6-hydroxy-6-methyl-3-heptanone, pheromone components of the male mouse, Mus musculus, were achieved to provide sufficient amounts of samples for biological studies.

The identification of attractive volatiles in aged male mouse urine.

In many species, older males are often preferred mates because they carry "good" genes that account for their viability. In some animals, including mice, which rely heavily on chemical communication, there is some indication that an animal's age can be determined by its scent. In order to identify the attractants in aged male mouse urine, chemical and behavioral studies were performed.

Effect of an orally ingested mugwort and mushroom extract mixture on urine odor from aged mice.

We had previously found that male mice could be trained to discriminate between the urine odor of aged and young adult (adult) mice. We hypothesized that these odors that characterized the older animals might be inhibited by a mixture of extracts (AAM) of mugwort and mushroom, because previous studies have indicated that these extracts could be used to reduce the intensity of unpleasant body odors. The findings of this chemical study strongly suggest that the AAM function helped to modify the aged mouse urine odor so that it more closely resembled the smell of urine from younger mice.

Experimental study of fatigue provoked by biotin deficiency in mice.

We investigated the relationships among behavioral parameters, forced-swimming test parameters, and plasma and organ biotin concentrations in biotin-deficient mice. Male ddY mice were divided into four groups: early biotin deficiency group (ED group; biotin-free diet for three weeks), progressive biotin-deficiency group (PD group; biotin-free diet for seven weeks), and two age-matched control groups. The dermatological symptoms of frank biotin deficiency were observed in most mice in the PD groups (72.

Co-administration of proline and inorganic iron enhance the improvement of behavioral and hematological function of iron-deficient anemic rats.

We investigated the interrelationships between behavior and serum amino acid concentrations in iron-deficient anemic rats. Concentrations of proline, alanine, glycine, and phenylalanine in serum samples were significantly higher than those in rats fed a normal diet, while serum threonine, glutamic acid, and valine levels were significantly lower. Activities of locomotion, rearing, hole-poking, and grooming, determined by using a hole board apparatus, were significantly reduced in anemic rats.