70 research outputs found

    Changes in functioning of mesolimbic incentive processing circuits during the premenstrual phase

    Get PDF
    The premenstrual phase of the menstrual cycle is associated with marked changes in normal and abnormal motivated behaviors. Animal studies suggest that such effects may result from actions of gonadal hormones on the mesolimbic dopamine (DA) system. We therefore investigated premenstrual changes in reward-related neural activity in terminal regions of the DA system in humans. Twenty-eight healthy young women underwent functional magnetic resonance imaging on 2 days during the menstrual cycle, once during the late follicular phase and once during the premenstrual phase, in counterbalanced order. Using a modified version of the monetary incentive delay task, we assessed responsiveness of the ventral striatum to reward anticipation. Our results show enhanced ventral striatal responses during the premenstrual as compared to the follicular phase. Moreover, this effect was most pronounced in women reporting more premenstrual symptoms. These findings provide support for the notion that changes in functioning of mesolimbic incentive processing circuits may underlie premenstrual changes in motivated behaviors. Notably, increases in reward-cue responsiveness have previously been associated with DA withdrawal states. Our findings therefore suggest that the sharp decline of gonadal hormone levels in the premenstrual phase may trigger a similar withdrawal-like state

    The relationship between weight gain during pregnancy and allopregnanolone levels : a longitudinal study

    No full text
    Objective: Large weight gain during pregnancy is a risk factor for complications for mother and fetus. Hunger and satiety are regulated in the hypothalamus, where the gamma-amino-butyric acid system (GABA) has an important role. Allopregnanolone, a progesterone metabolite, increases during pregnancy and is a potent GABA-A receptor modulating steroid. Allopregnanolone has been shown to induce overeating in rodents. The aim was to investigate whether there is a relationship between weight gain and allopregnanolone concentrations during pregnancy in humans. Design: A longitudinal, cohort study. Methods: Pregnant women (n = 56) were recruited in primary care in northern Sweden. Allopregnanolone concentrations in plasma were measured using radioimmunoassay and weight was measured in gestational weeks 12 and 35. Results: Weight increase correlated significantly to allopregnanolone in late pregnancy increase (r(s) = 0.320; P = 0.016), indicating a positive relationship between weight increase and allopregnanolone increase. A positive relationship was also noted between allopregnanolone in the 35th gestational week and weight increase. Women who gained = 11 kg during pregnancy showed higher allopregnanolone concentrations in week 35 and higher increase compared to women who increased < 11 kg (P = 0.006 and P = 0.009 resp.). There was no difference in weight or allopregnanolone concentrations at the onset of pregnancy. Conclusions: The results show a relationship between weight gain during pregnancy and increase in allopregnanolone concentrations

    Positive GABAA receptor modulating steroids and their antagonists : Implications for clinical treatments

    No full text
    GABA is the main inhibitory neurotransmitter in the brain and GABAergic transmission has been shown to be of importance for regulation of mood, memory and food intake. The progesterone metabolite allopregnanolone (Allo) is a positive GABAA receptor modulating steroid with potent effects. In humans, disorders such as premenstrual dysphoric disorder (PMDD), hepatic encephalopathy and polycystic ovarian syndrome are associated with elevated Allo levels and increased negative mood, disturbed memory and increased food intake in some individuals. This is surprising because Allo shares many properties with benzodiazepines and is mainly considered to be anxiolytic and anti-depressant. However, it is well established that, in certain individuals, GABAA receptor activating compounds could have paradoxical effects and thus be anxiogenic in low physiological plasma concentrations but anxiolytic at high levels. We have demonstrated that isoallopregnanolone (Isoallo), the 3β-OH sibling of Allo, functions as a GABAA receptor modulating steroid antagonist (GAMSA) but without any effects of its own on GABAA receptors. The antagonistic effect is noted in most GABAA subtypes investigated in vitro to date. In vivo, Isoallo can inhibit Allo-induced anaesthesia in rats, as well as sedation or saccadic eye velocity in humans. Isoallo treatment has been studied in women with PMDD. In a first phase II study, Isoallo (Sepranolone; Asarina Pharma) injections significantly ameliorated negative mood in women with PMDD compared with placebo. Several GAMSAs for oral administration have also been developed. The GAMSA, UC1011, can inhibit Allo induced memory disturbances in rats and an oral GAMSA, GR3027, has been shown to restore learning and motor coordination in rats with hepatic encephalopathy. In humans, vigilance, cognition and pathological electroencephalogram were improved in patients with hepatic encephalopathy on treatment with GR3027. In conclusion GAMSAs are a new possible treatment for disorders and symptoms caused by hyperactivity in the GABAA system

    Body fat percentage and CRP correlates with a composite score of vascular risk markers in healthy, young adults : The Lifestyle, Biomarkers, and Atherosclerosis (LBA) study

    No full text
    Background: Identification of early signs of atherosclerosis in young adults have the potential to guide early interventions to prevent later cardiovascular disease. We therefore analyzed measures of vascular structure and function and biomarkers of cardiovascular risk in a sample of young healthy adults. Methods: Pulse-wave velocity (PWV), carotid-intima media thickness (cIMT) and augmentation index (AIX) were measured in 834 healthy non-smokers (ages 18.0-25.9). Emphasis was put on discriminating between individuals having a vascular structure and function associated with a higher or lower risk, and cluster analysis algorithms were employed to assign the subjects into groups based on these vascular measurements. In addition, a vascular status score (VSS) was calculated by summarizing the results according to quintiles of the vascular measurements. The associations between VSS and cardiovascular biomarkers were examined by regression analyses. Results: The cluster analyses did not yield sufficiently distinct clustering (groups of individuals that could be categorized unequivocally as having either a vascular structure and function associated with a higher or lower CVD risk). VSS proved a better classificatory variable. The associations between VSS and biomarkers of cardiovascular risk were analyzed by univariable and multivariable regressions. Only body fat percentage and C-reactive protein (CRP) were independently associated with VSS. Conclusions: A VSS calculation, which integrates PWV, cIMT, and AIX measurements is better suited for cardiovascular risk evaluation in young adults than cluster analyses. The independent associations of VSS with body fat percentage and CRP highlight the decisive role of adiposity and systemic inflammation in early atherosclerotic progression and suggests a subordinate role of insulin and lipid metabolism in this age span

    Shielding Effectiveness Study of Two Fabrics with Microwave Properties Before and After High Power Irradiation

    No full text
    Over the past decade several applications forfabrics with electromagnetic properties have emerged, most ofthem relating to garments, including jackets with built-inantennas and workwear with increased radar visibility. Besidethese have surfaced two protective applications, namely toprotect transports of confidential equipment from discoveryand identification; and to protect sensitive apparatus fromdamage by high power electromagnetic irradiation e.g. in fieldoperations. In this paper results are presented frommeasurement of shielding effectiveness before and after highpower radiation for two types of fabrics under considerationfor the latter applications. Shielding effectivenessmeasurements have been conducted between 1 and 18 GHzwhile the high power irradiationQC 20151104. QC 20160129</p

    Shielding Effectiveness Study of Two Fabrics with Microwave Properties Before and After High Power Irradiation

    No full text
    Over the past decade several applications forfabrics with electromagnetic properties have emerged, most ofthem relating to garments, including jackets with built-inantennas and workwear with increased radar visibility. Besidethese have surfaced two protective applications, namely toprotect transports of confidential equipment from discoveryand identification; and to protect sensitive apparatus fromdamage by high power electromagnetic irradiation e.g. in fieldoperations. In this paper results are presented frommeasurement of shielding effectiveness before and after highpower radiation for two types of fabrics under considerationfor the latter applications. Shielding effectivenessmeasurements have been conducted between 1 and 18 GHzwhile the high power irradiationQC 20151104. QC 20160129</p
    corecore