Contribution of cosmetic ingredients and skin care textures to emotions.

OBJECTIVE: Emotions play an important role in consumers' perception of a sensory experience. The objective of this work was to investigate the ability of basic skin care formulas (i.e. without interference of odour, colour and packaging) and pillar ingredients (i.e. emollients and rheology modifiers) to elicit emotions. Another objective was to track, as claimed by neurocosmetics, the possible effect of formulas to trigger emotions from their direct biochemical effects on the skin. METHODS: Standard methodologies were mobilized, combining subjective and behavioural parameters (i.e. verbatim, prosody and gesture). Sense and Story methodology based on a collection of metaphoric verbatim was conducted after an induction phase. In addition, an experimental electrophysiological real-time visualization method was tried as a first experience in cosmetics. Finally, the ability of formulations with emotional benefits to modulate the release of neuropeptides by sensory neurons was evaluated on a 3D human model (epidermis co-cultured with sensory neurons). RESULTS: Skin care formulas were shown to play a role in emotional potential and the types of emotion generated, while changing one ingredient mostly acted on the intensity of the emotions. Verbatim provided contrasted answers depending on the protocol, highlighting the interest of non-verbal approaches to detect subtle effects. The in vitro model substantiated physiological effects of skin care formulas with emotional potential on human skin sensory neuron activity. CONCLUSION: Emotions were impacted by the change in ingredients and were better captured through non-verbal methods.

OBJECTIF: Les émotions jouent un rôle important dans la perception qu'ont les consommateurs d'une expérience sensorielle. L'objectif de ce travail était d'étudier la capacité de formules de soins pour la peau de base (c'est­à­dire sans interférence d'odeur, de couleur, d'emballage) et d' ingrédients essentiels (c'est­à­dire les émollients et les modificateurs de rhéologie) à susciter des émotions. Un autre objectif était de suivre, comme le prétendent les neurocosmétiques, l'effet possible des formules à déclencher des émotions à partir de leurs effets biochimiques directs sur la peau. MÉTHODES: Des méthodologies standards ont été mises en œuvre, combinant des paramètres subjectifs et comportementaux (c'est­à­dire verbatim, prosodie et gestuelle). La méthodologie Sense & Story basée sur un ensemble de verbatim métaphoriques a été mise en œuvre après une phase d'induction. En outre, une méthode expérimentale de visualisation électrophysiologique en temps réel a été testée comme première expérience dans le domaine des cosmétiques. Enfin, la capacité des formulations présentant des bénéfices émotionnels à moduler la libération de neuropeptides par les neurones sensoriels a été évaluée sur un modèle humain 3D (épiderme co­cultivé avec des neurones sensoriels). RÉSULTATS: Il a été démontré que les formules de soins pour la peau jouent un rôle dans le potentiel émotionnel et les types d'émotions générées, tandis que le changement d'un ingrédient agit principalement sur l'intensité des émotions. Le verbatim a fourni des réponses contrastées selon le protocole, soulignant l'intérêt des approches non verbales pour détecter les effets subtils. Le modèle in vitro a confirmé les effets physiologiques des formules de soins pour la peau ayant un potentiel émotionnel sur l'activité des neurones sensoriels de la peau humaine. CONCLUSION: Les émotions ont été affectées par le changement d'ingrédients et ont été mieux saisies par des méthodes non verbales.

Physiological benefits associated with facial skincare: Well-being from emotional perception to neuromodulation.

OBJECTIVE: This study aimed to demonstrate the specific nature of well-being induced by a facial skincare by deciphering its physiological and psychological impacts out of a therapeutic context. METHODS: Objective and subjective evaluations were performed on two groups of healthy participants. One group of 32 participants received 1-h facial skincare, while the second group of 31 participants were subjected to a resting condition during the same period. Electroencephalography, electrocardiography, electromyography, and respiratory rate measurements were assessed before and after both experimental conditions. Prosody and semantic analyses were also performed to evaluate the emotional perception in both groups. RESULTS: Physiological relaxation was observed after both experimental sessions; however, the effect was higher after the facial skincare. The cerebral, cardiac, respiratory, and muscular relaxation induced by facial skincare was 42%, 13%, 12%, and 17% higher, respectively, than that induced by the resting condition. In addition, non-verbal and verbal assessments showed that positive emotions were more markedly associated with the perception of facial skincare. CONCLUSION: The comparison between parameters recorded after a rest period allowed us to distinguish the physiological and psychological signature of facial skincare. Moreover, our results suggest an involvement of positive emotions in the physiological relaxation enhancement. All these observations contribute to the very scarce data available on the specific profile of well-being associated with facial skincare.

OBJECTIF: Cette étude visait à démontrer la nature spécifique du bien-être, induit par un soin du visage, en décryptant son impact physiologique et psychologique en dehors d'un contexte thérapeutique. MÉTHODES: Des évaluations objectives et subjectives ont été réalisées sur deux groupes de participants sains. Le premier groupe, de 32 participants, a reçu un soin du visage d'une heure ; tandis que le second groupe, de 31 participants, a été soumis à une session de repos de même durée. Des mesures d'électroencéphalographie, d'électrocardiographie, d'électromyographie, ainsi que de fréquence respiratoire, ont été enregistrées avant et après ces deux conditions expérimentales. Des analyses prosodiques et sémantiques ont également été effectuées, pour évaluer la perception émotionnelle dans chacun des deux groupes. RÉSULTATS: Une relaxation physiologique a été observée après les deux sessions expérimentales ; cependant, celle-ci fût plus importante après le soin du visage. En effet, comparativement à la session de repos, le soin du visage a induit une relaxation cérébrale, mais aussi cardiaque, respiratoire et musculaire, plus élevées de 42%, 13%, 12% et 17%, respectivement. De plus, les évaluations verbales et non verbales ont montré que les émotions positives étaient nettement plus associées à la perception du soin du visage, plutôt qu'à celle du repos. CONCLUSION: Cette étude comparative nous a permis de distinguer la signature physiologique, mais aussi psychologique, du soin du visage. Egalement, nos résultats suggèrent une implication des émotions positives dans l'amélioration de la relaxation physiologique. Ces observations contribuent à enrichir les rares données disponibles sur le profil spécifique du bien-être associé au soin du visage.

3Rs-based optimization of mice behavioral testing: The habituation/dishabituation olfactory test.

BACKGROUND: There is clear evidence that most of the paradigms that are used in the field of behavioral neuroscience suffer from a lack of reliability mainly because of oversimplification of both testing procedures and interpretations. In the present study we show how an already existing behavioral test, the olfactory habituation / dishabituation task, can be optimized in such a way that animal number and animal distress could be minimized, number/confidence of behavioral outcomes and number of explored behavioral dimensions could be increased. NEW METHOD: We used ethologically relevant technical and procedural changes associated with videotracking-based automated quantification of sniffing behavior to validate our new setup. Mainly internal and construct validity were challenged through the implementation of a series of simple experiments. RESULTS: We show that the new version of the test: 1) has very good within and inter laboratory replicability, 2) is sensitive to some environmental / experimental factors while insensitive to others, 3) allows investigating hedonism, both state and trait anxiety, efficacy of anxiolytic molecules, acute stress, mental retardation-related social impairments and learning and memory. 4) We also show that interest for both nonsocial and social odors is stable over time which makes repetitive testing possible. CONCLUSIONS: This work paves the way for future studies showing how behavioral tests / procedures may be improved by using ethologically relevant changes, in order to question laboratory animals more adequately. Refining behavioral tests may considerably increase predictivity of preclinical tests and, ultimately, help reinforcing translational research.

Maternal exposure to lipopolysaccharide leads to transient motor dysfunction in neonatal rats.

Epidemiological and experimental data implicate maternal infection and inflammation in the etiology of brain white matter injury, which may lead to cerebral palsy in preterm newborns. Our aim was to investigate motor development of the offspring after maternal administration of lipopolysaccharide (LPS). Wistar rats were intraperitoneally injected with Escherichia coli LPS or saline on gestational days 19 and 20. From birth to 3 weeks, pups were tested for neurobehavioral development, neurological signs and reflexes. From 3 to 6 weeks, motor coordination was investigated. At 4 months, animals were tested for locomotion. Brain myelination was assessed by myelin basic protein immunohistochemistry. Days of appearance of several neurological reflexes were significantly delayed, and neonate LPS pups displayed retarded performance in righting, gait and negative geotaxis. At the juvenile stage, LPS animals showed important impairment in coordination. However, although the LPS group performed worse in most tests, they reached vehicle levels by 5 weeks. At 4 months, LPS animals did not show variations in locomotion performances compared to vehicle. No myelination differences have been observed in the brains at adulthood. Maternal LPS administration results in delayed motor development even though these alterations fade to reach control level by 5 weeks. Motor impairments observed at the early stage in this study could be linked to previously reported hypomyelination of the white matter induced by maternal LPS challenge in the neonates. Finally, the normal myelination shown here at adulthood may explain the functional recovery of the animals and suggest either a potential remyelination of the brain or a delayed myelination in LPS pups.

Psychosocial stress, emotions and cytokine-related disorders.

It is quite clear from our daily experiences that psychosocial stress and emotional factors affects immunity and health. Moreover, from the first pioneer studies in the emerging field of study concerning the relations between emotions and immunity, stress has been commonly associated with immune-suppression. However, several evidence reveal a more complex relationship between emotions and immunity, thus offering new insights for the study of the impact of emotional factors in the onset, development or severity of many disorders, including autoimmune diseases. The present review summarizes background data concerning the crosstalk between brain and immune system and emphasizes the role of cytokines (in addition to the extensive influence of cathecolamines and glucocorticoid hormones) as key-molecules and discusses related patents.

Changes in social exploration of a lipopolysaccharides-treated conspecific in mice: role of environmental cues.

Despite the many advantages offered by sociality in animals, one of its main drawbacks is the increased propensity to be exposed to parasites and pathogens. In infection (bacteria and viruses), one of the common symptoms used to describe an animal experiencing an acute inflammation is a "social disinterest". According to the literature, this reduction in social behaviors would be an adaptive feature preventing further contamination. However, if the case of parasitic infection has been extensively studied, concerning inflammatory processes, no direct evidence of a proper isolation of sick animals by healthy conspecifics has been provided. The present study aimed to investigate the effects of endotoxin-induced inflammation (LPS, lipopolysaccharides) on the behavior of healthy conspecifics to verify a possible active social isolation of the immune-challenged animal. In addition, we applied variations to the functional significance of the situation by pre-exposing healthy subjects to unsanitary olfactory cues (i.e., 1,5-diaminopentane, odor of decaying flesh). Observations revealed several results: (1) no agonistic behavior was observed during dyadic encounter, whatever the immune status of the conspecifics or the olfactory stimulation; (2) endotoxin-induced inflammation triggered several behavioral changes in healthy conspecifics: increased inter-individual distance, decreased physical contacts, and changes in the modalities of social exploration (increased proportion of muzzle sniffing and decreased proportion of ano-genital sniffing); (3) these effects were more salient after olfactory priming with 1-,5-diaminopentane. Our data reveal that mice are able to discriminate the "state of sickness" in conspecifics use this information to support pertinent behavioral changes. Moreover, these results support the idea that mice would switch from a "controlled exposure" strategy under standard condition to a "pathogen avoidance" strategy under a specific unsanitary context.

Why women use makeup: implication of psychological traits in makeup functions.

Makeup acts and stimulates three of our senses: touch (which encompasses all sensations from the body surface), smell (fragrance), and sight (the process of becoming and looking beautiful). The positive stimulation of these senses by makeup can induce sensory as well as psychological pleasure. In order to understand the relationship of women to their makeup, we interviewed different groups of women on their quality of life and makeup habits. Then, through four standard well-validated psychometric self-questionnaires, we examined the possible relation between the need to make up oneself and specific psychological features. Our first results clearly showed that makeup could support two opposite "up" functions, i.e., "camouflage" vs "seduction." Concerning their psychological profiles, results showed that women of the functional class "camouflage" are more anxious, defensive, and emotionally unstable compared to those of the functional class "seduction," who appear to be more sociable, assertive, and extroverted. Further analyses revealed a division of the two classes into subclasses of volunteers with opposed personality and psychological profiles. This new classification allowed us to define more precisely the relations existing within the subjective experience of women during the makeup process. In conclusion, our study revealed that beyond the simple application of colorful products on the face, makeup has two major functional implications depending on specific psychological profiles of women.

Assessment of positive emotions in animals to improve their welfare.

It is now widely accepted that good welfare is not simply the absence of negative experiences, but rather is primarily the presence of positive experiences such as pleasure. However scientific investigation of positive emotions has long been neglected. This paper addresses two main issues: first, it reviews the current state of scientific knowledge that supports the existence of positive affective states in animals and, second, it suggests possible applications of this knowledge that may enhance quality of life under animal management conditions. In the first part of the paper, recent advances in psychology and neuroscience are reviewed to provide pragmatic frameworks based on cognitive processes (such as positive anticipation, contrast and controllability) for further investigations of positive emotions in animals. Thereafter, the neurobiological bases of positive emotions are highlighted in order to identify behavioral and physiological expressions of positive experiences in animals. Monitoring both the autonomic nervous system (via heart rate and its variability) and the immune system could offer relevant tools to better assess emotional states in animals, complementary to classical adrenocortical measures. In the second part of the paper, useful strategies for enhancing positive experiences (such as physical, social and cognitive enrichment or putative genetic selection) are outlined. Then this paper emphasizes practical applications for assessing and promoting positive emotions that may help in providing animals with a better quality of life. Play, affiliative behaviors and some vocalizations appear to be the most promising convenient indicators for assessing positive experiences in laboratory and farm animals under commercial conditions.

Immunity and emotions: lipopolysaccharide increases defensive behaviours and potentiates despair in mice.

Many studies have pointed out the relationships between immunity and depression, supporting a neuroimmune hypothesis of depressive disorders. However, despite the growing interest for such a hypothesis and the amount of clinical and experimental data available, the precise nature of this relationship between immunity and depression remains unclear. The present study aimed to investigate further the link between depression and immunity in mice using the modified version of the forced-swimming test. Based on a two-session test, results from our first experiment showed that endotoxin enhanced active defensive behaviours in mice during the first exposure to water, but was associated with increased immobility (i.e., 'behavioural despair') in the subsequent session. In our second experiment, we showed that these effects were blocked by a chronic antidepressant treatment with imipramine. Finally, we suggest a link between immunity and depression, based on the behavioural context in which immune activation takes place. We hypothesize that immune activation, by enhancing reactivity to the negative features of a given situation, increases defensive motivation of subjects, but therefore makes them more vulnerable to the deleterious emotional consequences of failure in defensive strategies.

The taste of sickness: lipopolysaccharide-induced finickiness in rats.

Decrease in food intake is one of the most documented non-specific symptoms of inflammatory processes. However, attention has been mainly focused on quantitative analysis. The present paper reports studies undertaken to test the possible contribution of changes in taste processes in inflammatory-induced alteration of feeding behavior. In a first experiment, the effects of lipopolysaccharide-induced sickness were assessed on preference for saccharin and aversion for quinine in rats using the two-bottle test paradigm. In a second experiment, effect of lipopolysaccharide (LPS) on the behavioral reactivity to palatable, unpalatable and mixed solutions was analyzed using the taste-reactivity paradigm. Our results show that LPS decreased total fluid intake but did not change taste responses to unpalatable or palatable substances. However, LPS increased aversive reactions and decreased hedonic responses to mixed taste. These LPS-induced changes are interpreted as an increase in finickiness and are discussed in regard to their potential role in the adaptation of individuals to sickness.