| 1. |
- Bendre, Megha
(författare)
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Predictors of Alcohol Misuse : Role of MAOA Genotype, Methylation, Transcription, and Negative and Positive Environmental factors
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Alcohol misuse is a risk factor for alcohol use disorder (AUD). Gene-environment interactions contribute to the risk or resilience for AUD. A functional polymorphism in the promoter of the monoamine oxidase A gene (MAOA-uVNTR), in interaction with negative environment (Eneg), is associated with alcohol misuse and AUD. Men carrying short (MAOA-S), and women carrying long (MAOA-L), MAOA-uVNTR alleles who experienced maltreatment or poor parent-child relationships are at increased susceptibility to alcohol misuse and AUD. This thesis assessed whether the association of MAOAxEneg with the risk of AUD is moderated by MAOA methylation or positive environment and whether MAOA methylation-associated changes in MAOA expression in the stress- and reward-related brain regions is an underlying mechanism.The thesis reveals that the association of MAOAxEneg with alcohol misuse is moderated by MAOA methylation in men, but not in women. In the clinical sample, men carrying MAOA-S allele who experienced maltreatment and had low MAOA methylation displayed higher alcohol-related problems than those without maltreatment or MAOA-L carriers with and without maltreatment. Furthermore, the quality of the parent–child relationship moderated the association of MAOAxEneg with alcohol misuse in a sex- and AUD stage-dependent manner. In the non-clinical sample of adolescents, girls carrying MAOA-L allele who experienced maltreatment and poor parent–child relationship displayed higher alcohol consumption, whereas those with average or good parent–child relationship had lower alcohol consumption. In the clinical sample of adolescents, however, no such association was observed. These results suggest that a good parent–child relationship protects MAOA susceptibility genotype carriers exposed to maltreatment during the early stages of alcohol use. The preclinical studies revealed that the male rats exposed to Eneg and alcohol had higher CpG-specific Maoa promoter methylation, which was associated with lower Maoa expression in the nucleus accumbens than the control rats. Thus, MAOA methylation-associated changes in MAOA expression in the nucleus accumbens might mediate the effect of environment on alcohol use.The thesis contributes to the understanding of biological mechanisms underlying MAOAxEnvironment effect and the critical role of MAOA methylation and positive environment in moderating risk and resilience for AUD. Also, the identification of subgroups may benefit from personalised interventions for AUD.
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| 2. |
- Vadlin, Sofia, 1973-
(författare)
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Problematic Gaming and Gambling among Adolescents
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aims of this thesis were to develop and evaluate a screening instrument designed to detect gaming addiction symptoms in adolescents, to study associations between problematic gaming and psychiatric symptoms, to investigate the stability of problematic gaming, and to examine possible associations between gaming at baseline (W1) with problem gambling three years later (W2).The study population consisted of adolescents from the Survey of Adolescent Life in Västmanland SALVe Cohort (adolescents in Västmanland born in 1997 and 1999, and their parents), in two waves (2012, n = 1887; 2015, n = 1576), and adolescents from child and adolescent psychiatric clinics in Västmanland (2014, n = 242).The development of the Gaming Addiction Identification Test (GAIT) was based upon the research literature on gaming, gambling, and addiction. An expert panel estimated the content validity of the GAIT and found it to be excellent. Additional psychometric evaluations of the GAIT and the parent version, GAIT-P, were conducted and it was found that both versions showed promising psychometric results, with high internal consistency, high concurrent validity, high concordance, unidimensionality, and high factor loadings, although poor model fit in exploratory factor analysis. Self- and parent-rated prevalence of gaming addiction symptoms were estimated at 1.3% with the GAIT and 2.4% with the GAIT-P in 13- and 15-year-olds.Self-rated problematic gaming above the cutoff had a boy to girl ratio of approximately 5:1 in both the SALVe Cohort and the clinical sample, whereas more girls than boys reported symptoms above the cutoff for ADHD, depression, anxiety, and psychotic-like-experiences. ADHD, depression, and anxiety symptoms were associated with odds ratios of 2.43, 2.47, and 2.06, respectively, in relation to coexisting problematic gaming. Furthermore, problematic gaming was stable over time, and problematic gaming at the first wave was associated with problem gambling three years later.It is important to screen for possible co-occurring symptoms among those who seek treatment and among those who appear to have symptoms of gaming, gambling, or psychiatric symptoms. Ongoing evaluation of adequate screening and diagnostic measurements, and the development and evaluation of treatments for problematic gaming, gaming addiction, and comorbid conditions are needed.
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| 3. |
- Immenschuh, Jana, 1994-
(författare)
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Aromatase, sex hormones and the young adult brain
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The enzyme aromatase coded by the gene CYP19A1/Cyp19a1 (humans/animals) catalyses the conversion of androgens into oestrogens, which play an important role in brain function from development through adulthood. Together with the sex hormones, aromatase seems to influence behaviour and cognition by affecting neurogenesis, differentiation, neuroplasticity, and neuroprotection. It is highly expressed in the limbic brain, suggesting a link to sex differences in mental health, including nicotine addiction, gambling disorder and resilience to early life stress (ELS) as well as structural properties of the brain. However, the underlying molecular mechanisms remain unclear. The studies of the present dissertation explored the distribution and influence of aromatase and sex hormones in rat and human brains, using different molecular biological methods, cognitive testing, as well as multimodal neuroimaging. Using fluorescence in-situ hybridization in the rat brain, Cyp19a1 expression was observed in the limbic regions and found to be higher in males compared to females, with the highest expression in the medial amygdala and the bed nucleus of the stria terminalis. Most Cyp19a1-expressing cells were GABAergic, some glutamatergic, and a small population of astrocytes expressing the gene was found. Furthermore, the expression of Cyp19a1 was observed to be lower in the medial prefrontal cortex (mPFC) of male rats exposed to ELS compared to controls, and a relationship between ELS and DNA methylation in the Cyp19a1 gene was detected. Using magnetic resonance imaging combined with [11C]cetrozole positron emission tomography in young adult women, aromatase availability (AA) was observed in the thalamus, the amygdala and the hypothalamus. A positive correlation with grey matter volume in those regions was found, together with a relationship between AA and the volume and cortical thickness of the mPFC and the volume and microstructure of the fornix. Additionally, an acute dose of nicotine was able to reduce AA in the thalamus. Experimental testing in young women showed an effect of menstrual cycle phase on reward-based decision-making and suggested a possible interaction between oestradiol and nicotine. In conclusion, these findings show for the first time in rats that aromatase is sex-, region- and cell type-specifically expressed and is affected by ELS. Moreover, in women aromatase is shown to be related to brain morphology and can be inhibited by nicotine, while fluctuating oestradiol influences cognition both alone and possibly in an interplay with nicotine. These findings advance our knowledge on the role of aromatase in the brain and the theoretical framework of psychoneuroendocrinology.
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| 4. |
- Kaltsouni, Elisavet
(författare)
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Neuroimaging progesterone receptor modulation in patients with premenstrual dysphoric disorder : Is it just in your head?
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Premenstrual dysphoric disorder (PMDD) is a menstrually related mood disorder affecting about 5% of women during their reproductive years. The disorder is cyclic, with the symptomatology namely occurring at the luteal phase of a menstrual cycle, for most ovulatory menstrual cycles and entails a series of mood and physical symptoms. A neural susceptibility to regular hormonal fluctuations is hypothesized as the neuropathophysiological mechanism. While treatment options, such as selective serotonin reuptake inhibitors and hormonal interventions, are available, the neural mechanisms underlying symptom relief remain largely unclear. In this series of studies, a multimodal neuroimaging design was approach was used to reveal the neural correlates of three-month, low-dose selective progesterone receptor modulator (SPRM) treatment in comparison to a placebo. This treatment has been demonstrated to be effective in alleviating psychological symptoms associated with PMDD. Thirty-five women with fulfilling the criteria of a PMDD diagnosis were randomized to treatment with SPRM or placebo, with structural and functional MRI scans conducted before and after randomization. Findings indicated enhanced fronto-cingulate activity during a reactive aggression task in the SPRM treatment group compared to placebo, along with a negative association between aggressive responding and brain activity in the placebo group. Resting state functional connectivity was additionally altered after treatment with SPRM in fronto-visual, temporo-insular, and temporo-cerebellar regions. Additionally, a positive correlation was observed between the reduction in cortisol levels and the decrease in temporo-insular connectivity. No treatment effects were observed on brain structure, including grey and white matter volume, as well as cortical surface architecture. Lastly, White matter microstructure integrity did not differ longitudinally but showed cross-sectional differences. In conclusion, the effects of SPRM treatment were primarily observed in brain function, specifically in terms of enhanced cognitive control processing in the context of reactive aggression and resting state functional connectivity in regions relevant to cognitive and sensorimotor processing, with no significant structural alterations noted. Taken together, these findings confirm that the fluctuations rather than absolute levels of ovarian hormones are primary contributing to premenstrual symptomatology, potentially through hormonal-state dependent functional correlates.
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| 5. |
- Viereckel, Thomas, 1987-
(författare)
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United in Diversity : A Physiological and Molecular Characterization of Subpopulations in the Basal Ganglia Circuitry
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Basal Ganglia consist of a number of different nuclei that form a diverse circuitry of GABAergic, dopaminergic and glutamatergic neurons. This complex network is further organized in subcircuits that govern limbic and motor functions in humans and other vertebrates. Due to the interconnection of the individual structures, dysfunction in one area or cell population can affect the entire network, leading to synaptic and molecular alterations in the circuitry as a whole. The studies in this doctoral thesis aimed at characterizing restricted subpopulations of neurons in the Basal Ganglia circuitry and their importance in the wider function of the network. To this end, we identified subpopulations of neurons in the subthalamic nucleus (STN), substantia nigra (SN) and ventral tegmental area (VTA), characterized their molecular profile and investigated their physiological role in the circuitry.Within the mouse STN, reduction of glutamatergic neurotransmission in a subpopulation expressing Paired-like homeodomain transcription factor 2 (Pitx2) led to structural alterations in the nucleus as well as biochemical alterations of the dopaminergic system in the Nucleus accumbens (NAc) and changes in reward-related behavior. In the ventral midbrain, we identified and characterized novel marker genes selective to the VTA or SN. Of these, transient receptor potential cation channel subfamily V member 1 (TrpV1) marks a population of mainly glutamatergic neurons in the VTA which project to the NAc, while gastrin releasing peptide (Grp) is expressed in a population of dopaminergic neurons neuroprotected in Parkinson's disease. Furthermore, we discovered that disruption of glutamatergic co-release of dopaminergic neurons expressing dopamine transporter (DAT), diminishes fast EPSCs and glutamate release but does not affect the acquisition of reward-related behavioral tasks. To selectively quantify glutamate release from specific subpopulations, we devised a technique combining glutamate-amperometry and optogenetics. This was used to measure glutamate released from Pitx2-expressing synaptic terminals in the Globus pallidus as well as DAT- or TrpV1-expressing terminals in the NAc.In summary, this doctoral thesis has furthered understanding of the function and importance of specific subpopulations within the Basal Ganglia circuitry and provides a novel means to investigate glutamate in the intact rodent brain within clearly defined, restricted cell populations.
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| 6. |
- Stiernman, Louise, 1994-
(författare)
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Premenstrual dysphoric disorder : brain structure and function, GABAA-active neurosteroids and GABAA receptor plasticity
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background Premenstrual dysphoric disorder (PMDD) is an ovarian hormone-bound disorder, characterized by mood symptoms which occur exclusively during the luteal phase of the menstrual cycle. Previous neuroimaging studies of PMDD have primarily reported functional brain differences during the luteal phase in regions of the salience network (SN), which is commonly implicated in mood and anxiety disorders. SN dysfunction may mediate affective and behavioral deficits by leading to enhanced detection and inappropriate assignment of salience to stimuli. What drives altered brain function in PMDD is unknown. However, one influential hypothesis implicates the luteal phase hormone progesterone, and in particular its neurosteroid metabolites. Progesterone-derived neurosteroids increase transmission at the g- aminobutyric acid type A (GABAA) receptor, leading to increased inhibitory tone at the neuronal level. This thesis aimed to i) investigate structural and functional characteristics of the brain in PMDD, ii) relate functional measures to levels of neurosteroids during the luteal phase, and iii) investigate how gene expression of GABAA receptor subunits is altered across the menstrual cycle in PMDD.Results In Study I, we found that women with PMDD had thinner cortices in widespread brain regions, including regions of the SN. In Studies II and III, we found that increases in functional brain measures are most prominent during the symptomatic luteal phase in regions belonging to the SN and in other networks commonly involved in the psychopathology of mood disorders. Furthermore, we could show that increased activity in key nodes of the SN was apparent in the follicular phase and related to the severity of affective symptoms experienced during the luteal phase. Additionally, in Study II, we found that functional activity in the amygdala, a key region of the SN, was differentially associated with serum levels of GABAA receptor- active neurosteroids between PMDD and controls during the luteal phase. Lastly, in Study IV, we found seminal evidence of reduced mRNA expression of the d-GABAA subunit, which imbues GABAA receptors with increased sensitivity to progesterone’s neurosteroid metabolites. Lower expression of d subunits was related to higher amygdala reactivity.Conclusion In this thesis, I provide evidence for altered structure and function in multiple brain networks, particularly the SN in PMDD. Accentuated SN dysfunction during the symptomatic luteal phase may be mediated by the amygdala, and related to abnormal deficits in the expression of neurosteroid-sensitive d- GABAA receptors in response to ovarian hormone fluctuations.
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| 7. |
- Dubol, Manon, et al.
(författare)
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Acute nicotine exposure blocks aromatase in the limbic brain of healthy women : A [11C]cetrozole PET study
- 2023
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Ingår i: Comprehensive Psychiatry. - : Elsevier. - 0010-440X .- 1532-8384. ; 123
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Tidskriftsartikel (refereegranskat)abstract
- Background: Of interest to women's mental health, a wealth of studies suggests sex differences in nicotine addiction and treatment response, but their psychoneuroendocrine underpinnings remain largely unknown. A pathway involving sex steroids could indeed be involved in the behavioural effects of nicotine, as it was found to inhibit aromatase in vitro and in vivo in rodents and non-human primates, respectively. Aromatase regulates the synthesis of oestrogens and, of relevance to addiction, is highly expressed in the limbic brain.Methods: The present study sought to investigate in vivo aromatase availability in relation to exposure to nicotine in healthy women. Structural magnetic resonance imaging and two [11C]cetrozole positron emission tomography (PET) scans were performed to assess the availability of aromatase before and after administration of nicotine. Gonadal hormones and cotinine levels were measured. Given the region-specific expression of aromatase, a ROI -based approach was employed to assess changes in [11C]cetrozole non-displaceable binding potential.Results: The highest availability of aromatase was found in the right and left thalamus. Upon nicotine exposure, [11C]cetrozole binding in the thalamus was acutely decreased bilaterally (Cohen's d =-0.99). In line, cotinine levels were negatively associated with aromatase availability in the thalamus, although as non-significant trend.Conclusions: These findings indicate acute blocking of aromatase availability by nicotine in the thalamic area. This suggests a new putative mechanism mediating the effects of nicotine on human behaviour, particularly relevant to sex differences in nicotine addiction.
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| 8. |
- Iliadis, Stavros I, 1983-
(författare)
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Personality and the HPA-axis in Association with Postpartum Depression
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Postpartum depression is a psychiatric disorder affecting a substantial proportion of newly delivered women, and remains a significant cause of childbirth-related morbidity. The aim of the present thesis was to examine psychological, endocrine and genetic aspects of postpartum depression in a large, population-based sample of women in Uppsala, Sweden. All included studies were undertaken as parts of the BASIC-project, a longitudinal study on psychological wellbeing during pregnancy and the postpartum period. Study participants were screened for depressive symptoms in pregnancy week 17 and 32 as well as at six weeks and six months postpartum, mainly by use of the Swedish version of the Edinburgh Postnatal Depression Scale (EPDS). Furthermore, personality was assessed with the Swedish universities Scale of Personality (SSP) in pregnancy week 32. Evening cortisol levels in saliva were measured in pregnancy week 36 and at six weeks postpartum. Blood samples were obtained to measure corticotropin-releasing hormone levels (CRH) and to perform genetic analyses. The results of this thesis demonstrate that neuroticism is a strong and independent predictive factor of depressive symptoms at six weeks and six months postpartum, and has a significant mediatory role in the association between a single nucleotide polymorphism in the hydroxysteroid (11-beta) dehydrogenase 1 gene (HSD11B1) and postpartum depression. Furthermore, women with postpartum depressive symptoms present with a dysregulated hypothalamic-pituitary-adrenal axis activity in terms of elevated cortisol levels postpartum, as well as elevated CRH levels in mid-gestation. In conclusion, this thesis develops current knowledge on several attributes of postpartum depression. Further studies are required to replicate and expand on these results, which would further contribute to early identification of women at risk of postpartum depression and adoption of proper interventions that may moderate the short- and long-term consequences of the disorder.
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| 9. |
- Kaltsouni, Elisavet, et al.
(författare)
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Selective progesterone receptor modulation and brain activity at rest in patients with premenstrual dysphoric disorder
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Ovarian hormones have been indicated to impact brain connectivity and mood. However, there is no consistent evidence on hormone-dependent functional connectivity and mental health. Alterations in resting state networks have been suggested as markers of affective disorders, but only preliminary evidence is provided on premenstrual dysphoric disorder, in which symptoms occur upon fluctuations of ovarian hormones. Recently, three-month low-dose selective progesterone receptor modulator (SPRM) administration has been associated with symptom relief and altered task-based brain reactivity during a reactive aggression condition. The present study sought to investigate the effect of this treatment on resting state functional connectivity (rs-FC) in patients with PMDD. Seed-based analyses were conducted, including including seeds from the classic resting state networks along with the functional cluster affected by SPRM treatment. Within previously identified networks related with emotional processing, rs-FC was compared between individuals with PMDD during the symptomatic luteal phase before randomization to treatment or placebo and during the end of the last treatment cycle. Seed-based rs-FC analyses yielded significant treatment by time effects on rs-FC between the left posterior superior temporal gyrus and the right insula cortex, between the posterior cerebellum and the left temporal pole, and between the right lateral visual network and left superior frontal gyrus. Visuo-frontal luteal phase connectivity decreased for the SPRM group and was positively correlated with changes in mood symptom severity in the placebo group. Cerebellar and temporal connectivity increased for the SPRM treatment group, while temporo-insular connectivity decreased and was positively correlated with cortisol levels. These findings indicate that SPRM treatment influenced rs-FC, which could be a relevant mechanism behind symptom alleviation.
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| 10. |
- Kaltsouni, Elisavet, et al.
(författare)
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White matter integrity upon progesterone antagonism in individuals with premenstrual dysphoric disorder: a randomized placebo-controlled diffusion tensor imaging study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Premenstrual dysphoric disorder (PMDD) is a depressive disorder triggered by fluctuations of progesterone and estradiol during the luteal phase of the menstrual cycle. Selective progesterone receptor modulation (SPRM), while exerting an antagonistic effect on progesterone and maintaining the estradiol on moderate levels, has shown beneficial effects on the mental symptoms of PMDD. Progesterone is also known for its neuroprotective effects, while synthetic progestins have been suggested to promote myelination. However, the impact of this treatment on white matter neuroanatomy is unexplored. Diffusion tensor imaging was used to collect data on white matter integrity in patients with PMDD, before and after treatment with ulipristal acetate (an SPRM) or placebo, as part of a double-blind randomized controlled-trial. Tract based spatial statistics were performed to investigate SPRM treatment vs. placebo longitudinal effects on fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) on the whole white matter skeleton. Voxel-wise analyses indicated no change over time in any white matter microstructure metrics in individuals treated with SPRM versus placebo. Improvement in PMDD symptoms did not correlate with changes in white matter microstructure. In secondary, cross-sectional comparisons during treatment, the SPRM group displayed lower FA and higher MD, RD, and AD in several tracts. The main findings suggest that SPRM treatment did not impact white matter microstructure. However, the between-group differences after treatment call for further investigation on the tracts potentially impacted by progesterone antagonism.
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