| 1. |
- Hansson, Anita C., et al.
(författare)
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Oxytocin Reduces Alcohol Cue-Reactivity in Alcohol-Dependent Rats and Humans
- 2018
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Ingår i: Neuropsychopharmacology. - : NATURE PUBLISHING GROUP. - 0893-133X .- 1740-634X. ; 43:6, s. 1235-1246
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Tidskriftsartikel (refereegranskat)abstract
- Approved pharmacological treatments for alcohol use disorder are limited in their effectiveness, and new drugs that can easily be translated into the clinic are warranted. One of those candidates is oxytocin because of its interaction with several alcohol-induced effects. Alcoholdependent rats as well as post-mortem brains of human alcoholics and controls were analyzed for the expression of the oxytocin system by qRT-PCR, in situ hybridizaton, receptor autoradiography ([(125)l]OVTA binding), and immunohistochemistry. Alcohol self administration and cue-induced reinstatement behavior was measured after intracerebroventicular injection of 10 nM oxytocin in dependent rats. Here we show a pronounced upregulation of oxytocin receptors in brain tissues of alcohol dependent rats and deceased alcoholics, primarily in frontal and striatal areas. This upregulation stems most likely from reduced oxytocin expression in hypothalamic nuclei. Pharmacological validaton showed that oxytocin reduced cue-induced reinstatement response in dependent rats-an effect that was not observed in nondependent rats. Finally, a clinical pilot study (German clinical trial number DRKS00009253) using functional magnetic resonance imaging in heavy social male drinkers showed that intranasal oxytocin (24 IU) decreased neural cue-reactivity in brain networks similar to those detected in dependent rats and humans with increased oxytocin receptor expression. These studies suggest that oxytocin might be used as an anticraving medication and thus may positvely affect treatment outcomes in alcoholics.
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| 2. |
- Zillich, Lea, et al.
(författare)
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Multi-omics signatures of alcohol use disorder in the dorsal and ventral striatum
- 2022
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Ingår i: Translational Psychiatry. - : Springer Nature. - 2158-3188. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Alcohol Use Disorder (AUD) is a major contributor to global mortality and morbidity. Postmortem human brain tissue enables the investigation of molecular mechanisms of AUD in the neurocircuitry of addiction. We aimed to identify differentially expressed (DE) genes in the ventral and dorsal striatum between individuals with AUD and controls, and to integrate the results with findings from genome- and epigenome-wide association studies (GWAS/EWAS) to identify functionally relevant molecular mechanisms of AUD. DNA-methylation and gene expression (RNA-seq) data was generated from postmortem brain samples of 48 individuals with AUD and 51 controls from the ventral striatum (VS) and the dorsal striatal regions caudate nucleus (CN) and putamen (PUT). We identified DE genes using DESeq2, performed gene-set enrichment analysis (GSEA), and tested enrichment of DE genes in results of GWASs using MAGMA. Weighted correlation network analysis (WGCNA) was performed for DNA-methylation and gene expression data and gene overlap was tested. Differential gene expression was observed in the dorsal (FDR < 0.05), but not the ventral striatum of AUD cases. In the VS, DE genes at FDR < 0.25 were overrepresented in a recent GWAS of problematic alcohol use. The ARHGEF15 gene was upregulated in all three brain regions. GSEA in CN and VS pointed towards cell-structure associated GO-terms and in PUT towards immune pathways. The WGCNA modules most strongly associated with AUD showed strong enrichment for immune response and inflammation pathways. Our integrated analysis of multi-omics data sets provides further evidence for the importance of immune- and inflammation-related processes in AUD.
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| 3. |
- Bazov, Igor, 1973-, et al.
(författare)
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Dynorphin and κ-Opioid Receptor Dysregulation in the Dopaminergic Reward System of Human Alcoholics.
- 2018
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Ingår i: Molecular Neurobiology. - : Springer. - 0893-7648 .- 1559-1182. ; 55:8, s. 7049-7061
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Tidskriftsartikel (refereegranskat)abstract
- Molecular changes induced by excessive alcohol consumption may underlie formation of dysphoric state during acute and protracted alcohol withdrawal which leads to craving and relapse. A main molecular addiction hypothesis is that the upregulation of the dynorphin (DYN)/κ-opioid receptor (KOR) system in the nucleus accumbens (NAc) of alcohol-dependent individuals causes the imbalance in activity of D1- and D2 dopamine receptor (DR) expressing neural circuits that results in dysphoria. We here analyzed post-mortem NAc samples of human alcoholics to assess changes in prodynorphin (PDYN) and KOR (OPRK1) gene expression and co-expression (transcriptionally coordinated) patterns. To address alterations in D1- and D2-receptor circuits, we studied the regulatory interactions between these pathways and the DYN/KOR system. No significant differences in PDYN and OPRK1 gene expression levels between alcoholics and controls were evident. However, PDYN and OPRK1 showed transcriptionally coordinated pattern that was significantly different between alcoholics and controls. A downregulation of DRD1 but not DRD2 expression was seen in alcoholics. Expression of DRD1 and DRD2 strongly correlated with that of PDYN and OPRK1 suggesting high levels of transcriptional coordination between these gene clusters. The differences in expression and co-expression patterns were not due to the decline in neuronal proportion in alcoholic brain and thereby represent transcriptional phenomena. Dysregulation of DYN/KOR system and dopamine signaling through both alterations in co-expression patterns of opioid genes and decreased DRD1 gene expression may contribute to imbalance in the activity of D1- and D2-containing pathways which may lead to the negative affective state in human alcoholics.
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| 4. |
- Björk, Karl, et al.
(författare)
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β-Arrestin 2 knockout mice exhibit sensitized dopamine release and increased reward in response to a low dose of alcohol
- 2013
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Ingår i: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 230:3, s. 439-449
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Tidskriftsartikel (refereegranskat)abstract
- RationaleThe rewarding effects of alcohol have been attributed to interactions between opioid and dopaminergic system within the mesolimbic reward pathway. We have previously shown that ablation of β-arrestin 2 (Arrb2), a crucial regulator of μ-opioid receptor function, attenuates alcohol-induced hyperlocomotion and c-fos activation in the nucleus accumbens.ObjectivesHere, we further investigated the role of Arrb2 in modulating alcohol-induced dopamine (DA) release and conditioned place preference (CPP). We also assessed the functional importance of Arrb2 for μ-opioid receptor surface expression and signaling following an acute alcohol challenge.MethodsAlcohol-evoked (0.375, 0.75, and 1.5 g/kg intraperitoneally) DA release was measured by in vivo microdialysis in the shell of nucleus accumbens. Reward was assessed by the CPP paradigm. Receptor function was assessed by μ-receptor binding and [35S]GTP-γ-S autoradiography.ResultsIn Arrb2 knockout mice accumbal DA levels reach maximum response at a lower dose compared to wild-type (wt) animals. In line with these results, Arrb2 knockout mice display increased CPP for alcohol as compared to wt mice. Finally, Arrb2 mutant mice display increased μ-opioid receptor signaling in the ventral and dorsal striatum and amygdala in response to a low dose of alcohol, indicating impaired desensitization mechanisms in these mice.ConclusionsOur results show that Arrb2 modulates the response to low doses of alcohol on various levels including μ-opioid receptor signaling, DA release, and reward. They also reveal a clear dissociation between the effects of Arrb2 on psychomotor and reward behaviors.
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| 5. |
- Blom, Elin S, et al.
(författare)
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Increased mRNA Levels of TCF7L2 and MYC of the Wnt Pathway in Tg-ArcSwe Mice and Alzheimer's Disease Brain
- 2010
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Ingår i: International journal of Alzheimer's disease. - : Hindawi Limited. - 2090-0252 .- 2090-8024. ; 2011, s. 936580-
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Tidskriftsartikel (refereegranskat)abstract
- Several components in the Wnt pathway, including β-catenin and glycogen synthase kinase 3 beta, have been implied in AD pathogenesis. Here, mRNA brain levels from five-month-old tg-ArcSwe and nontransgenic mice were compared using Affymetrix microarray analysis. With surprisingly small overall changes, Wnt signaling was the most affected pathway with altered expression of nine genes in tg-ArcSwe mice. When analyzing mRNA levels of these genes in human brain, transcription factor 7-like 2 (TCF7L2) and v-myc myelocytomatosis viral oncogene homolog (MYC), were increased in Alzheimer's disease (AD) (P < .05). Furthermore, no clear differences in TCF7L2 and MYC mRNA were found in brains with frontotemporal lobar degeneration, suggesting that altered regulation of these Wnt-related genes could be specific to AD. Finally, mRNA levels of three neurogenesis markers were analyzed. Increased mRNA levels of dihydropyrimidinase-like 3 were observed in AD brain, suggesting that altered Wnt pathway regulation may signify synaptic rearrangement or neurogenesis.
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| 6. |
- Cippitelli, Andrea, et al.
(författare)
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Neuropeptide Y (NPY) suppresses yohimbine-induced reinstatement of alcohol seeking
- 2010
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Ingår i: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 208:3, s. 417-426
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Reinstatement of responding to a previously alcohol-associated lever following extinction is an established model of relapse-like behavior and can be triggered by stress exposure. Here, we examined whether neuropeptide Y (NPY), an endogenous anti-stress mediator, blocks reinstatement of alcohol-seeking induced by the pharmacological stressor yohimbine.MATERIALS AND METHODS: NPY [5.0 or 10.0 mug/rat, intracerebroventricularly (ICV)] dose-dependently blocked the reinstatement of alcohol seeking induced by yohimbine (1.25 mg/kg, i.p.) but failed to significantly suppress the maintenance of alcohol self-administration. We then used c-fos expression mapping to examine neuronal activation following treatment with yohimbine or NPY alone or yohimbine following NPY pre-treatment.RESULTS AND DISCUSSION: The analysis was focused on a network of structures previously implicated in yohimbine-induced reinstatement, comprised of central (CeA) and basolateral (BLA) amygdala and the shell of the nucleus accumbens (Nc AccS). Within this network, both yohimbine and NPY potently induced neuronal activation, and their effects were additive, presumably indicating activation of excitatory and inhibitory neuronal populations, respectively.CONCLUSION: These results suggest that NPY selectively suppresses relapse to alcohol seeking induced by stressful events and support the NPY system as an attractive target for the treatment of alcohol addiction.
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| 7. |
- Domi, Esi, et al.
(författare)
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Genetic Deletion of Neuronal PPAR gamma Enhances the Emotional Response to Acute Stress and Exacerbates Anxiety: An Effect Reversed by Rescue of Amygdala PPAR gamma Function
- 2016
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Ingår i: JOURNAL OF NEUROSCIENCE. - : SOC NEUROSCIENCE. - 0270-6474. ; 36:50, s. 12611-12623
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Tidskriftsartikel (refereegranskat)abstract
- PPAR gamma is one of the three isoforms of the Peroxisome Proliferator-Activated Receptors (PPARs). PPAR gamma is activated by thiazolidinediones such as pioglitazone and is targeted to treat insulin resistance. PPAR gamma is densely expressed in brain areas involved in regulation of motivational and emotional processes. Here, we investigated the role of PPAR gamma in the brain and explored its role in anxiety and stress responses in mice. The results show that stimulation of PPAR gamma by pioglitazone did not affect basal anxiety, but fully prevented the anxiogenic effect of acute stress. Using mice with genetic ablation of neuronal PPAR gamma (PPAR gamma(NestinCre)), we demonstrated that a lack of receptors, specifically in neurons, exacerbated basal anxiety and enhanced stress sensitivity. The administration of GW9662, a selective PPAR gamma antagonist, elicited a marked anxiogenic response in PPAR gamma wild-type (WT), but not in PPAR gamma(NestinCre) knock-out (KO) mice. Using c-Fos immunohistochemistry, we observed that acute stress exposure resulted in a different pattern of neuronal activation in the amygdala (AMY) and the hippocampus (HIPP) of PPAR gamma(NestinCre) KO mice compared with WT mice. No differences were found between WT and KO mice in hypothalamic regions responsible for hormonal response to stress or in blood corticosterone levels. Microinjection of pioglitazone into the AMY, but not into the HIPP, abolished the anxiogenic response elicited by acute stress. Results also showed that, in both regions, PPAR gamma colocalizes with GABAergic cells. These findings demonstrate that neuronal PPAR gamma is involved the regulation of the stress response and that the AMY is a key substrate for the anxiolytic effect of PPAR gamma
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| 8. |
- Domi, Esi, et al.
(författare)
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Nicotine increases alcohol self-administration in male rats via a mu-opioid mechanism within the mesolimbic pathway
- 2020
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Ingår i: British Journal of Pharmacology. - : WILEY. - 0007-1188 .- 1476-5381. ; 177:19, s. 4516-4531
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Alcohol and nicotine use disorders are commonly comorbid. Both alcohol and nicotine can activate opioid systems in reward-related brain regions, leading to adaptive changes in opioid signalling upon chronic exposure. The potential role of these adaptations for comorbidity is presently unknown. Here, we examined the contribution of mu and kappa-opioid receptors to nicotine-induced escalation of alcohol self-administration in rats. Experimental Approach: Chronic nicotine was tested on alcohol self-administration and motivation to obtain alcohol. We then tested the effect of the kappa antagonist CERC-501 and the preferential mu receptor antagonist naltrexone on basal and nicotine-escalated alcohol self-administration. To probe mu or kappa receptor adaptations, receptor binding and G-protein coupling assays were performed in reward-related brain regions. Finally, dopaminergic activity in response to alcohol was examined, using phosphorylation of DARPP-32 in nucleus accumbens as a biomarker. Key Results: Nicotine robustly induced escalation of alcohol self-administration and motivation to obtain alcohol. This was blocked by naltrexone but not by CERC-501. Escalation of alcohol self-administration was associated with decreased DAMGO-stimulated mu receptor signalling in the ventral tegmental area (VTA) and decreased pDARPP-32 in the nucleus accumbens shell in response to alcohol. Conclusions and Implications: Collectively, these results suggest that nicotine contributes to escalate alcohol self-administration through a dysregulation of mu receptor activity in the VTA. These data imply that targeting mu rather than kappa receptors may be the preferred pharmacotherapeutic approach for the treatment of alcohol use disorder when nicotine use contributes to alcohol consumption.
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| 9. |
- Festari, Cristina, et al.
(författare)
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European consensus for the diagnosis of MCI and mild dementia : Preparatory phase
- 2023
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Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 19:5, s. 1729-1741
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Etiological diagnosis of neurocognitive disorders of middle-old age relies on biomarkers, although evidence for their rational use is incomplete. A European task force is defining a diagnostic workflow where expert experience fills evidence gaps for biomarker validity and prioritization. We report methodology and preliminary results. Methods: Using a Delphi consensus method supported by a systematic literature review, 22 delegates from 11 relevant scientific societies defined workflow assumptions. Results: We extracted diagnostic accuracy figures from literature on the use of biomarkers in the diagnosis of main forms of neurocognitive disorders. Supported by this evidence, panelists defined clinical setting (specialist outpatient service), application stage (MCI-mild dementia), and detailed pre-assessment screening (clinical-neuropsychological evaluations, brain imaging, and blood tests). Discussion: The Delphi consensus on these assumptions set the stage for the development of the first pan-European workflow for biomarkers’ use in the etiological diagnosis of middle-old age neurocognitive disorders at MCI-mild dementia stages. Highlights: Rational use of biomarkers in neurocognitive disorders lacks consensus in Europe. A consensus of experts will define a workflow for the rational use of biomarkers. The diagnostic workflow will be patient-centered and based on clinical presentation. The workflow will be updated as new evidence accrues.
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| 10. |
- Heilig, Markus, et al.
(författare)
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Translating the neuroscience of alcoholism into clinical treatments : from blocking the buzz to curing the blues
- 2010
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Ingår i: Neuroscience and Biobehavioral Reviews. - : Elsevier. - 0149-7634 .- 1873-7528. ; 35:2, s. 334-344
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the pathophysiology of addictive disorders is critical for development of new treatments. A major focus of addiction research has for a long time been on systems that mediate acute positively reinforcing effects of addictive drugs, most prominently the mesolimbic dopaminergic (DA) system and its connections. This research line has been successful in shedding light on the physiology of both natural and drug reward, but has not led to therapeutic breakthroughs. The role of classical reward systems is perhaps least clear in alcohol addiction. Here, recent work is summarized that points to some clinically important conclusions. First, important pharmacogenetic differences exist with regard to positively reinforcing effects of alcohol and the ability of this drug to activate classical reward pathways. This offers an opportunity for personalized treatment approaches in alcoholism. Second, brain stress and fear systems become pathologically activated in later stages of alcoholism and their activation is a major influence in escalation of alcohol intake, sensitization of stress responses, and susceptibility to relapse. These findings offer a new category of treatment mechanisms. Corticotropin-releasing hormone (CRH) signaling through CRH1 receptors is a major candidate target in this category, but recent data indicate that antagonists for substance P (SP) neurokinin 1 (NK1) receptors may have a similar potential.
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