Global ETD Search

11	Social Buffering By Unfamiliar Adult Males In Preweaning Guinea Pigs (Cavia Pocellus): The Effects On HPA Activity And Fos Induction In The Medial Prefrontal Cortex Watanasriyakul, Withayapon 04 May 2016 (has links) No description available. Psychobiology Psychology Behavioral Psychology Neurosciences HPA Cortisol Social Buffering mPFC Prelimbic Infralimbic Preweaning Guinea Pigs Social Interactions
12	Optogenetic Inhibition of the mPFC During Delay Discounting Shelby M White (6615890) 10 June 2019 (has links) <p> <i>Impulsivity</i>, or the tendency to act prematurely without foresight, has been linked to a diverse range of pathological conditions. Foresight refers to the ability to envision future rewards and events (i.e. prospectively sample) and has been associated with decreased impulsivity. One form of impulsivity is measured by the ability to delay gratification and is often studied in the framework of Delay Discounting (DD). DD provides the means to study impulsivity in a number of pathological conditions. However, whether impulsivity precedes the development of pathological states or results from the pathological state itself is not fully understood. This necessitates an understanding of neurobiological mechanisms contributing to decision making in both non-impulsive as well as impulsive populations of individuals. </p> <p> Animal models allow invasive techniques to be used to dissect the neurocircuitry involved in decision making. Given that the decision-making process is an ongoing process rather than an isolated event, optogenetics provide the temporal and spatial specificity necessary for evaluating brain region specific contributions to decision making in DD. In the present study, optogenetics were used to assess the contribution of the medial Prefrontal Cortex (mPFC), a brain region involved in ‘goal-directed’ behavior, in the planning of future choices (i.e. prospective plans) and subsequent measures of impulsivity in an adjusting amount DD procedure. Optogenetic inhibition of mPFC was conducted in Wistar rats during different epochs of a DD task in order to assess how mPFC affects planning behavior in a population of rat not considered to be highly impulsive. Although no direct effects on planning behavior (e.g. consistency) were observed, inhibiting mPFC after a trial has been initiated and directly before a choice was made (Epoch 2) was observed to increase measures of impulsivity in comparison to days where no optogenetic manipulation occurred in a delay-specific manner. This suggests that mPFC differentially contributes to decision making at different delays. A pattern of associations between choice latency, impulsivity, and consistency began to emerge for inactivation occurring in Epoch 2, suggesting that mPFC contributes to some aspect of planning choices during this epoch. Moreover, these results indicate that mPFC is involved in decision making in Wistar Rats. Understanding the direct role that mPFC plays in promoting choices of delayed rewards provides a neurobiological target for treatment aimed at reducing impulsivity in the clinical population.</p> Decision Making Optogenetics ArchT Wistar decision making Prospective Strategy delay discounting impulsive choice epoch-specific mPFC
13	Ovarian Steroid Hormones, Emotion Processing and Mood Gingnell, Malin January 2013 (has links) It is known that some psychiatric disorders may deteriorate in relation to the menstrual cycle. However, in some conditions, such as premenstrual dysphoric disorder (PMDD), symptomatology is triggered mainly by the variations in ovarian steroid hormones. Although symptoms induced by fluctuations in ovarian steroids often are affective, little is known about how emotion processing in women is influenced by variations, or actual levels, of ovarian steroid hormones. The general aim of this thesis was to evaluate menstrual cycle effects on reactivity in emotion generating and controlling areas in the corticolimbic system to emotional stimulation and anticipation, in healthy controls and women with PMDD. A second aim was to evaluate corticolimbic reactivity during long-term administration of exogenous ovarian steroids. In study I, III and IV effects of the menstrual cycle on emotional reactivity in women with PMDD was studied. In study I, women with PMDD in displayed higher amygdala reactivity than healthy controls to emotional faces, not in the luteal phase as was hypothesised, but in the follicular phase. No difference between menstrual cycle phases was obtained in women with PMDD, while healthy controls had an increased reactivity in the luteal phase. The results of study I was further elaborated in study III, where women with PMDD were observed to have an increased anticipatory reactivity to negative emotional stimuli. However, no differences in amygdala reactivity to emotional stimuli were obtained across the menstrual cycle. Finally, in study IV the hypothesis that amygdala reactivity increase in the luteal phase in women with PMDD is linked to social stimuli rather than generally arousing stimuli was suggested, tested and supported. In study II, re-exposure to COC induced mood symptoms de novo in women with a previous history of COC-induced adverse mood. Women treated with COC reported increased levels of mood symptoms both as compared to before treatment, and as compared to the placebo group. There was a relatively strong correlation between depressive scores before and during treatment. The effects of repeated COC administration on subjective measures and brain function were however dissociated with increased aversive experiences accompanied by reduced reactivity in the insular cortex. premenstrual dysphoric disorder menstrual cycle combined oral contraceptives estrogen estradiol progesterone ethinyl-estradiol levonorgestrel randomized clinical trial placebo fMRI amygdala ACC insula dlPFC mPFC IFG MFG
14	Reelin-immunreaktive Zellen im prälimbischen Kortex männlicher Ratten: Einfluss von Stress / Reelin-immunoreactive cells in the prelimbic cortex of male rats: influence of stress Koldehoff, Andreas Michael 27 March 2012 (has links) No description available. 610 Medizin, Gesundheit Medicine 44.90
15	Female-Specific Role of Ciliary Neurotrophic Factor in the Medial Amygdala in Promoting Stress Responses Jia, Cuihong, Gill, Wesley D., Lovins, Chiharu, Brown, Russell W., Hagg, Theo 01 March 2022 (has links) Ciliary neurotrophic factor (CNTF) is produced by astrocytes which have been implicated in regulating stress responses. We found that CNTF in the medial amygdala (MeA) promotes despair or passive coping, i.e., immobility in an acute forced swim stress, in female mice, while having no effect in males. Neutralizing CNTF antibody injected into the MeA of wildtype females reduced activation of downstream STAT3 (Y705) 24 and 48 h later. In concert, the antibody reduced immobility in the swim test in females and only after MeA injection, but not when injected in the central or basolateral amygdala. Antibody injected into the male MeA did not affect immobility. These data reveal a unique role of CNTF in female MeA in promoting despair or passive coping behavior. Moreover, 4 weeks of chronic unpredictable stress (CUS) increased immobility in the swim test and reduced sucrose preference in wildtype CNTF+/+, but not CNTF-/- littermate, females. Following CUS, 10 min of restraint stress increased plasma corticosterone levels only in CNTF+/+ females. In males, the CUS effects were present in both genotypes. Further, CUS increased CNTF expression in the MeA of female, but not male, mice. CUS did not alter CNTF in the female hippocampus, hypothalamus and bed nucleus of stria terminalis. This suggests that MeA CNTF has a female-specific role in promoting CUS-induced despair or passive coping, behavioral anhedonia and neuroendocrine responses. Compared to CNTF+/+ mice, CNTF-/- mice did not show differences in CUS-induced anxiety-like behavior and sensorimotor gating function as measured by elevated T-Maze, open field and pre-pulse inhibition of the acoustic startle response. Together, this study reveals a novel CNTF-mediated female-specific mechanism in stress responses and points to opportunities for developing treatments for stress-related disorders in women. anhedonia BLA basolateral amygdala BNST bed nucleus of stria terminalis CNTF ciliary neurotrophic factor CRF corticotropin releasing factor CUS chronic unpredictable stress CeA central amygdala Chronic unpredictable stress HPA hypothalamic-pituitary-adrenal Hyp hypothalamus IL-6 interleukin-6 LIF leukemia inhibitory factor MeA medial amygdala neuroendocrine response Neutralizing antibody PAG periaqueductal grey PTSD post-traumatic stress disorder PVN paraventricular nucleus passive stress-coping stereotaxic injection TNF tumor necrosis factor mPFC medial prefrontal cortex Biomedical Sciences

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