La douleur est un phénomène complexe régi par le système nerveux. De nombreuses molécules modulent la douleur par des mécanismes complexes et variés. L’une d’elle, l’ocytocine, est plus connue pour ses rôles dans la reproduction et les interactions sociales, mais est pourtant un puissant agent analgésique endogène. Au cours de cette thèse, j’ai cherché à comprendre comment l’ocytocine régulait la douleur dans deux différentes régions du cerveau, l’hypothalamus et l’amygdale. Ces travaux ont permis de mettre à jour un petit groupe de neurones ocytocinergiques de l’hypothalamus, qui contrôle la douleur par une action double, à la fois en inhibant la transmission du message douloureux dans la moelle épinière et en contrôlant en même temps l’activité d’autres neurones ocytocinergiques qui sécrètent alors de l’ocytocine dans la circulation sanguine. Dans l’amygdale, nous avons pu montrer que l’effet analgésique de l’ocytocine nécessitait le bon fonctionnement d’un type de cellule non neuronal, l’astrocyte, qui répond à la présence d’ocytocine et, ce faisant, permet l’activation de circuits de neurones contrôlant la douleur. / Pain is a complex phenomenon arising from the nervous system. Numerous molecules modulate pain through complex and various mechanisms. One of those, oxytocin, is more famous for its roles in reproduction and social interactions, but is also a potent endogenous analgesic. During this thesis, I tried to understand how oxytocin modulates pain in two brain regions, the hypothalamus and the amygdala. This work unveiled a small group of oxytocinergic neurons in the hypothalamus which control pain through a dual action, firstly by inhibiting the pain signals in the spinal cord and secondly by activating at the same time another population of oxytocinergic neurons, which then secrete oxytocin in the bloodstream. In the amygdala, we showed that the analgesic effect of oxytocin required the proper functioning of a non-neuronal cell type, the astrocyte, which responds to oxytocin and, doing so, allows the activation of neural circuits which modulate pain.

Obsessive-compulsive disorder (OCD), with a prevalence of 1-2 %, frequently leads a chronic course. Persons with OCD are often reluctant to seek help and, if they do, their OCD is often missed. This is unfortunate, since active treatment may substantially improve social function and quality of life. Serotonin reuptake inhibitors (SRIs) have welldocumented efficacy in OCD, but delayed response may be problematic. Methods to predict response have been lacking. Because SRIs are effective, pathophysiological research on OCD has focussed on serotonin. However, no clear aberrations of serotonin have been found, thus other mechanisms ought to be involved. Our aims were to facilitate clinical detection and assessment of OCD, to search for biochemical correlates of response and side-effects in SRI treatment of OCD and to identify any possible involvement of oxytocin in the pathophysiology of OCD. In study I, we tested in 402 psychiatric out-patients the psychometric properties of a concise rating scale, “Brief Obsessive Compulsive Scale” (BOCS). BOCS was shown to be easy to use and have excellent discriminant validity in relation to other common psychiatric diagnoses. Studies II-V were based on 36 OCD patients from a randomised controlled trial of paroxetine, clomipramine or placebo. In study II, contrary to expectation, we found that the change (decrease) of serotonin in whole blood was most pronounced in non-responders to SRI. This is likely to reflect inflammatory influence on platelet turnover rather than serotonergic processes within the central nervous system. In studies IV-V, we found relations between changes of oxytocin in plasma and the anti-obsessive response, and between oxytocin and the SRI related delay of orgasm, respectively. In both cases, the relation to central oxytocinergic mechanisms is unclear. In males, delayed orgasm predicted anti-obsessive response.

No description available.

Institute for Rural Development / MRDV

Human pleasant touches promote feelings of security, supportiveness, and wellbeing. Conversely, human unpleasant touches promote the body for either “fight or flight” or “short term acute stress” during emergencies, feeling of stress or danger. The promoted stress response is released from the hypothalamus by the sympathetic nerve system further to the spinal cord to reach the signals to the adrenal medulla, where stress hormones adrenaline is released. Adrenaline, which is characterized by a mimic sympathetic nerve system, interacts with α and β receptors on different organs. The aim for this study was to investigate whether the stroker (partner/stranger) touch effects on adrenaline hormone releases. The null hypothesis for this study entails a significant adrenaline reduction in partners’ touches compared with strangers’ touches. Indirect competitive ELISA method was used, and concentration data of a total of sixteen participants was obtained. Whitney-U test was carried out to compare group differences within stroker (stranger/partner) touches and adrenaline releasing level. In addition, correlation in adrenaline with noradrenaline and oxytocin hormones was obtained using Spearman’s correlation test. The significant p-value 0.05 was conducted. The result of this study showed no differences between stroker (partner/stranger) associated with adrenaline hormone release. Correlation between partner maximum (max) concentration data for both oxytocin and adrenaline had significant differences. However, max variables for adrenaline and noradrenaline within stroker did not show significant differences. The conclusion of this study is that the gentle touch stimulus used in this study was not enough to detect stress hormone in adrenaline.

No description available.

No description available.

In just over ten years, internet-based technologies revolutionized several aspects of daily human life, including social interactions. Social media sites (SNSs), such as Facebook, Instagram, and Twitter, have dramatically changed the way people keep in touch or make new acquaintances. On the flipside, recent research have highlighted the risk for and inappropriate use of SNSs, which might result in personal discomfort or a mental disorder. For this reason, it is important to understand how these issues develop starting from the diverse contexts and individual features. The main aim of the present Ph.D. project is to identify to which extent the interaction between psychological components, like perceived parental warmth, and genetic susceptibility to the familiar environment can describe the social behavior online and offline. The underlying hypothesis is that sensibility to the familiar context will represent a positive factor, if the person recalls a good perception of parental care, leading to confident psychological mechanisms in adulthood, hence to more optimal neural responses to social stressors in real life, and to the appropriate use of social media. To this aim, three studies have been performed: •Study 1. Analysis of the impact of perceived early social experience on the formation of interactional patterns in adult social interaction in two different countries (Italy and Singapore); •Study 2. Investigation on how the interaction between genetic features of oxytocin receptor gene polymorphisms and perceived early social experience affect the neurophysiological responses to cries; •Study 3. Exploration of the link between adult psychological dimensions related to social behavior and metrics of usage on Instagram platform. The experimental activities have been performed in two different laboratories: as for the Italian samples, questionnaires and genetic information were collected at the Affiliative Behavior and PhysiologyLaboratory in Rovereto; with regards to the Singaporean sample, participants completed the questionnaires, then were tested for genetics, Near InfraRed Spectroscopy (NIRS), Electrocardiogram (ECG) at the Social and Affective Neuroscience set in Nanyang Technological University. One of the purposes of the overall project was the construction of a rich database, which aims to include information about genetic polymorphisms proved to be sensitive to social environment (oxytocin receptor gene rs53576, rs2254298, and serotonin rs25531), recalled parental warmth, main dimensions of adult attachment, neural and physiological responses to social distress, like listening to cries, and behavior on two main social media platforms, such are Facebook and Instagram. This complex design gives the project several strengths, such as the possibility to focus on the contribution of diverse factors within a bio-psycho-i social frame, that is claimed to be the more appropriate by scientific community standard, in order to have a wider and deeper understanding of human behavior. Secondly, results generated from studies based on this database would allow filling the present gap about social media usage and psychological mechanisms, providing a further comparison with offline behavior. Lastly, results might be helpful when implemented in clinical work to understand if and how social media can become a useful mean in clinical work. The temporary fragility of this project is related to the genetic sample size, as a broader sampling would be necessary to have a comparable amount of the different variants and generate more reliable explanations. However, this data collection represents a starting point, as it resents of temporal constraints. Future efforts are necessary to enrich the dataset and to find appropriate methodologies to examine in depth the interaction between all the factors

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Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 6 uppsatser.