1. |
-
Alcohol and Alcohol-related Diseases
- 2023
-
Editorial collection (other academic/artistic)abstract
- Alcohol is one of the major risk factors for negative health outcomes worldwide. It accounts for more than 60 alcohol-related diseases, ranging from addiction, through liver cirrhosis, to cancer. Collectively, these conditions account for mortality and morbidity that make alcohol use one of the leading preventable causes of disability adjusted life-years (DALYs) lost globally. In this book, an international faculty covers all aspects of alcohol-related disorders, ranging from addiction/alcohol use disorders (AUD) to alcohol-related diseases of other organs such as liver, heart or cancer. A special focus is to reach out to primary care physicians who are in the front line of this major health problem. The book also provides an update for addiction specialists, as well as specialists in internal medicine, gastroenterology and hepatology. The book is divided into sections that include epidemiology, alcohol use disorders and addiction, alcohol-related liver disease, alcoholic hepatitis, primary care and interdisciplinary approaches and other alcohol-related diseases. Besides current diagnostic measures and treatment strategies, the book deals with the many underlying molecular and genetic mechanisms of alcohol toxicity. Novel insights include prospective data on all-cause mortality and the emerging major role of alcohol-mediated hemolysis and enhanced red blood cell turnover. The book also aims at guiding policy makers to handle the topic of alcohol in our society more responsibly.
|
|
2. |
- Aoun, E. G., et al.
(author)
-
A relationship between the aldosterone-mineralocorticoid receptor pathway and alcohol drinking: preliminary translational findings across rats, monkeys and humans
- 2018
-
In: Molecular Psychiatry. - : NATURE PUBLISHING GROUP. - 1359-4184 .- 1476-5578. ; 23:6, s. 1466-1473
-
Journal article (peer-reviewed)abstract
- Aldosterone regulates electrolyte and fluid homeostasis through binding to the mineralocorticoid receptors (MRs). Previous work provides evidence for a role of aldosterone in alcohol use disorders (AUDs). We tested the hypothesis that high functional activity of the mineralocorticoid endocrine pathway contributes to vulnerability for AUDs. In Study 1, we investigated the relationship between plasma aldosterone levels, ethanol self-administration and the expression of CYP11B2 and MR (NR3C2) genes in the prefrontal cortex area (PFC) and central nucleus of the amygdala (CeA) in monkeys. Aldosterone significantly increased after 6- and 12-month ethanol self-administration. NR3C2 expression in the CeA was negatively correlated to average ethanol intake during the 12 months. In Study 2, we measured Nr3c2 mRNA levels in the PFC and CeA of dependent and nondependent rats and the correlates with ethanol drinking during acute withdrawal. Low Nr3c2 expression levels in the CeA were significantly associated with increased anxiety-like behavior and compulsive-like drinking in dependent rats. In Study 3, the relationship between plasma aldosterone levels, alcohol drinking and craving was investigated in alcohol-dependent patients. Non-abstinent patients had significantly higher aldosterone levels than abstinent patients. Aldosterone levels positively correlated with the number of drinks consumed, craving and anxiety scores. These findings support a relationship between ethanol drinking and the aldosterone/MR pathway in three different species.
|
|
3. |
- Augier, Eric, et al.
(author)
-
The GABA(B) Positive Allosteric Modulator ADX71441 Attenuates Alcohol Self-Administration and Relapse to Alcohol Seeking in Rats
- 2017
-
In: Neuropsychopharmacology. - : NATURE PUBLISHING GROUP. - 0893-133X .- 1740-634X. ; 42:9, s. 1789-1799
-
Journal article (peer-reviewed)abstract
- GABAergic signaling is involved in modulating the reinforcing properties of alcohol, and GABA(B) receptors have been proposed as a potential target for clinical treatment of alcoholism. The orthosteric GABA(B) receptor agonist baclofen has been shown to suppress operant self-administration of alcohol in animals and alcohol use in alcohol-dependent patients, but its utility is limited by a narrow therapeutic index. We tested the effects of ADX71441, a novel GABA(B) receptor positive allosteric modulator, on alcohol-related behaviors in rats. We first assessed the effects of ADX71441 ( 1, 3, 10 and 30 mg/kg, I.P.) on both non-dependent and dependent male Wistar rats trained to self-administer 20% alcohol. We then determined the effects of ADX71441 on stress-induced as well as cue-induced relapse-like behavior. Finally, we sought to identify the brain regions through which ADX71441 may act to prevent relapse-like behavior by mapping the neuronal activation induced by stress-induced reinstatement of alcohol-seeking using c-Fos immunohistochemistry. ADX71441 dose-dependently decreased alcohol self-administration of both dependent and non-dependent animals, but its potency was higher in alcohol-dependent rats. Furthermore, both cue-and stress-induced alcohol seeking were blocked by the GABA(B) receptor positive allosteric modulator. Finally, pretreatment with 3 mg/kg of ADX71441 before stress-induced reinstatement significantly decreased c-Fos expression in a network of brain regions implicated in stress-induced relapse, comprising the nucleus accumbens shell, the dorsal raphe nucleus and the medial prefrontal cortex. Our findings support a causal role of GABAB receptors in alcohol reinforcement and relapse to alcohol seeking. These effects are observed in the absence of significant sedative side effects. Jointly, these observations indicate that GABAB receptor positive allosteric modulators merit being tested clinically for the treatment of alcoholism. Our data also point to a potential biomarker of target engagement for early clinical studies.
|
|
4. |
- Badiani, Aldo, et al.
(author)
-
Comments: Addiction research and theory: a commentary on the Surgeon Generals Report on alcohol, drugs, and health
- 2018
-
In: Addiction Biology. - : John Wiley & Sons. - 1355-6215 .- 1369-1600. ; 23:1, s. 3-5
-
Journal article (other academic/artistic)abstract
- The Office of the Surgeon General recently produced its first Report on the consequences of alcohol and drug abuse on health, making several very laudable policy recommendations. The Report also emphasizes the importance of adequate funding for biomedical research, which is good news for both researchers and patients. However, the Report is marred by a biased viewpoint on the psychology and neurobiology of drug addiction. We highlight here four controversial issues that were depicted as facts in the Report, thereby potentially misleading non-expert readers about the current state-of-the-art understanding of the psychology and neurobiology of drug addiction. It will be important to recognize a fuller range of scientific viewpoints in addiction neuroscience to avoid amplifying this bias in the coming years.
|
|
5. |
- Barbier, Estelle, et al.
(author)
-
DNA Methylation in the Medial Prefrontal Cortex Regulates Alcohol-Induced Behavior and Plasticity
- 2015
-
In: Journal of Neuroscience. - : Society for Neuroscience. - 0270-6474 .- 1529-2401. ; 35:15, s. 6153-6164
-
Journal article (peer-reviewed)abstract
- Recent studies have suggested an association between alcoholism and DNA methylation, a mechanism that can mediate long-lasting changes in gene transcription. Here, we examined the contribution of DNA methylation to the long-term behavioral and molecular changes induced by a history of alcohol dependence. In search of mechanisms underlying persistent rather than acute dependence-induced neuroadaptations, we studied the role of DNA methylation regulating medial prefrontal cortex (mPFC) gene expression and alcohol-related behaviors in rats 3 weeks into abstinence following alcohol dependence. Postdependent rats showed escalated alcohol intake, which was associated with increased DNA methylation as well as decreased expression of genes encoding synaptic proteins involved in neurotransmitter release in the mPFC. Infusion of the DNA methyltransferase inhibitor RG108 prevented both escalation of alcohol consumption and dependence-induced downregulation of 4 of the 7 transcripts modified in postdependent rats. Specifically, RG108 treatment directly reversed both downregulation of synaptotagmin 2 (Syt2) gene expression and hypermethylation on CpG#5 of its first exon. Lentiviral inhibition of Syt2 expression in the mPFC increased aversion-resistant alcohol drinking, supporting a mechanistic role of Syt2 in compulsive-like behavior. Our findings identified a functional role of DNA methylation in alcohol dependence-like behavioral phenotypes and a candidate gene network that may mediate its effects. Together, these data provide novel evidence for DNA methyltransferases as potential therapeutic targets in alcoholism.
|
|
6. |
- Barchiesi, Riccardo, 1989-
(author)
-
Overlapping Neural Substrates of Alcohol- and Anxiety-Related Behavior in the Rat
- 2021
-
Doctoral thesis (other academic/artistic)abstract
- Alcohol use is a leading cause of death and disease worldwide. A large part of this disease burden is associated with alcohol use disorder (AUD), a diagnostic category characterized by excessive use in spite of negative consequences ("compulsive use"), a loss of control over intake, and choice of alcohol over natural rewards. These behavioral symptoms are believed to reflect the emergence of persistent neuroadaptations in key brain regions that exert control over motivated behavior. A major challenge to addressing the treatment needs of patients with AUD is the high prevalence of co-occurring psychiatric disorders, of which anxiety disorders are the most common. Both AUD and anxiety disorders are characterized by broad changes in gene expression within brain regions that include the prelimbic cortex (PL) and the amygdala complex. Although the risk for AUD has a substantial genetic component, heavy alcohol use and stress also contribute to disease risk. Our lab previously identified DNA hypermethylation as a mechanism behind alcohol-induced downregulation of prelimbic Syt1 and Prdm2. In a subsequent study, our lab demonstrated a functional role of Prdm2 in alcohol-associated behaviors. In the work that constitutes this thesis, we have further investigated the behavioral consequences of Syt1 and Prdm2 downregulation. We found that Syt1 knock-down in the PL of non-dependent rats is sufficient to promote several behaviors that model critical aspects of AUD. We further identified the PL-basolateral amygdala (BLA) projection as a key brain circuit within which Syt1 knock-down promotes compulsive-like alcohol intake. In another study, we showed that Prdm2 knock-down in the PL increases the expression of fear memory, a central feature of anxiety disorders. Knock-down after memory formation (consolidation) did not increase the fear expression, indicating that Prdm2 regulates fear memory consolidation. We further showed that knock-down of Prdm2 in the PL-BLA projection was sufficient to promote the increased fear expression. Transcriptome analysis specifically in neurons projecting from the PL to the BLA showed a marked up-regulation of genes involved in synaptogenesis, suggesting that Prdm2 downregulation leads to excessive fear by strengthening fear memory consolidation in the PL-BLA circuit. In a third study, we used a model of social defeat- and witness stress to investigate mechanisms of co-occurring escalated alcohol intake and increased anxiety-like behavior ("comorbidity"). We recapitulated the broad range of individual stress responses observed in human populations. With gene expression analysis, we identified a marked upregulation of Avp in the amygdala of rats with "co-morbid" characteristics, and this upregulation correlated with the magnitude of the comorbidity. Together, our findings highlight the contribution of epigenetic mechanisms in regulating the behavioral consequences of alcohol-dependence, and identify specific downstream target genes whose expression is influenced by alcohol-induced epigenetic reprogramming to mediate long-term behavioral consequences. Our work also identifies amygdala Avp as a possible neurobiological substrate of individual susceptibility for stress-induced alcohol- and anxiety-related behaviors.
|
|
7. |
|
|
8. |
- Best, Laura M., et al.
(author)
-
Lower brain fatty acid amide hydrolase in treatment-seeking patients with alcohol use disorder: a positron emission tomography study with [C-11]CURB
- 2020
-
In: Neuropsychopharmacology. - : SPRINGERNATURE. - 0893-133X .- 1740-634X. ; 45:8, s. 1289-1296
-
Journal article (peer-reviewed)abstract
- The endocannabinoid enzyme, fatty acid amide hydrolase (FAAH), has been proposed as a therapeutic target for alcohol use disorder (AUD) and co-morbid psychiatric illnesses. Investigating this target in the living human brain and its relationship to clinical outcome is a critical step of informed drug development. Our objective was to establish whether brain FAAH levels are low in individuals with AUD and related to drinking behavior. In this pilot study, treatment-seeking patients with AUD completed two PET scans with the FAAH radiotracer [C-11]CURB after 3-7 days (n = 14) and 2-4 weeks (n = 9) of monitored abstinence. Healthy controls (n = 25) completed one scan. FAAH genetic polymorphism (rs324420) and blood concentrations of anandamide and other N-acylethanolamines metabolized by FAAH were determined and AUD symptoms assessed. In AUD, brain FAAH levels were globally lower than controls during early abstinence (F(1,36) = 5.447; p = 0.025)) and FAAH substrates (anandamide, oleoylethanolamide, and N-docosahexaenoylethanolamide) were significantly elevated (30-67%). No significant differences in FAAH or FAAH substrates were noted after 2-4 weeks abstinence. FAAH levels negatively correlated with drinks per week (r = -0.57, p = 0.032) and plasma concentrations of the three FAAH substrates (r > 0.57; p < 0.04)). Our findings suggest that early abstinence from alcohol in AUD is associated with transiently low brain FAAH levels, which are inversely related to heavier alcohol use and elevated plasma levels of FAAH substrates. Whether low FAAH is an adaptive beneficial response to chronic alcohol is unknown. Therapeutic strategies focusing on FAAH inhibition should consider the possibility that low FAAH during early abstinence may be related to drinking.
|
|
9. |
- Bilbao, Ainhoa, et al.
(author)
-
A Pharmacogenetic Determinant of Mu-Opioid Receptor Antagonist Effects on Alcohol Reward and Consumption : Evidence from Humanized Mice.
- 2015
-
In: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 77:10, s. 850-858
-
Journal article (peer-reviewed)abstract
- BACKGROUND: It has been proposed that therapeutic responses to naltrexone in alcoholism are moderated by variation at the mu-opioid receptor gene locus (OPRM1). This remains controversial because human results vary and no prospectively genotyped studies have been reported. We generated humanized mice carrying the respective human OPRM1 A118G alleles. Here, we used this model system to examine the role of OPRM1 A118G variation for opioid antagonist effects on alcohol responses.METHODS: Effects of naltrexone on alcohol reward were examined using intracranial self-stimulation. Effects of naltrexone or nalmefene on alcohol intake were examined in continuous access home cage two-bottle free-choice drinking and operant alcohol self-administration paradigms.RESULTS: Alcohol lowered brain stimulation reward thresholds in 118GG mice in a manner characteristic of rewarding drugs, and this effect was blocked by naltrexone. Brain stimulation reward thresholds were unchanged by alcohol or naltrexone in 118AA mice. In the home cage, increased alcohol intake emerged in 118GG mice with increasing alcohol concentrations and was 33% higher at 17% alcohol. At this concentration, naltrexone selectively suppressed alcohol intake in 118GG animals to a level virtually identical to that of 118AA mice. No effect of naltrexone was found in the latter group. Similarly, both naltrexone and nalmefene were more effective in suppressing operant alcohol self-administration in 118GG mice.CONCLUSIONS: In a model that allows close experimental control, OPRM1 A118G variation robustly moderates effects of opioid antagonism on alcohol reward and consumption. These findings strongly support a personalized medicine approach to alcoholism treatment that takes into account OPRM1 genotype.
|
|
10. |
- Bäckryd, Emmanuel, 1974-, et al.
(author)
-
Dynamiken i förskrivningen av opioider i Sverige 2000–2015 - Markanta omfördelningar inom opioidgruppen, men ingen »epidemi«
- 2017
-
In: Läkartidningen. - : Läkartidningen Förlag. - 0023-7205 .- 1652-7518. ; 114
-
Journal article (peer-reviewed)abstract
- Opioid prescription changes in Sweden 2000-2015 In contrast to the well-established »opioid epidemic« in the US, very little is known about how the prescription of opioids in Sweden has developed during the last decade. Aggregated data from the open Statistical database of the Swedish Board of Health and Welfare were analyzed descriptively. The yearly prevalence of opioid prescription did not change 2006-2015, but there were dramatic shifts in the choice of opioids. During this period, dextropropoxyphene was pulled off the market. Tramadol was used by fewer individuals (-54 % over the decade), but dosages expressed as Defined Daily Dose/patient/year (DDD/pat/y) increased (+41 %). In contrast, oxycodone and morphine were used by more individuals (+465 % and +137 %, respectively), but DDD/pat/y decreased during the period (-56% and -54%). Studies on non-aggregated data from available registries are needed to further elucidate the circumstances and possible consequences of these shifts in opioid prescription patterns.
|
|
11. |
- Böhme, Rebecca, et al.
(author)
-
Distinction of self-produced touch and social touch at cortical and spinal cord levels
- 2019
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 116:6, s. 2290-2299
-
Journal article (peer-reviewed)abstract
- Differentiation between self-produced tactile stimuli and touch by others is necessary for social interactions and for a coherent concept of "self." The mechanisms underlying this distinction are unknown. Here, we investigated the distinction between self-and other-produced light touch in healthy volunteers using three different approaches: fMRI, behavioral testing, and somatosensory-evoked potentials (SEPs) at spinal and cortical levels. Using fMRI, we found self-other differentiation in somatosensory and sociocognitive areas. Other-touch was related to activation in several areas, including somatosensory cortex, insula, superior temporal gyrus, supramarginal gyrus, striatum, amygdala, cerebellum, and prefrontal cortex. During self-touch, we instead found deactivation in insula, anterior cingulate cortex, superior temporal gyrus, amygdala, parahippocampal gyrus, and prefrontal areas. Deactivation extended into brain areas encoding low-level sensory representations, including thalamus and brainstem. These findings were replicated in a second cohort. During self-touch, the sensorimotor cortex was functionally connected to the insula, and the threshold for detection of an additional tactile stimulus was elevated. Differential encoding of self-vs. other-touch during fMRI correlated with the individual self-concept strength. In SEP, cortical amplitudes were reduced during self-touch, while latencies at cortical and spinal levels were faster for other-touch. We thus demonstrated a robust self-other distinction in brain areas related to somatosensory, social cognitive, and interoceptive processing. Signs of this distinction were evident at the spinal cord. Our results provide a framework for future studies in autism, schizophrenia, and emotionally unstable personality disorder, conditions where symptoms include social touch avoidance and poor self-vs.-other discrimination.
|
|
12. |
- Böhme, Rebecca, et al.
(author)
-
Sharpened self-other distinction in attention deficit hyperactivity disorder
- 2020
-
In: NeuroImage. - : Elsevier. - 2213-1582. ; 27
-
Journal article (peer-reviewed)abstract
- IntroductionDifferentiation between self-produced tactile stimuli and touch by others is necessary for social interactions and for a coherent concept of “self”. In attention-deficit-hyperactivity-disorder (ADHD), tactile hypersensitivity and social cognition problems are part of the symptomatology, but pathophysiological mechanisms are largely unknown. Differentiation of self- and non-self- generated sensations might be key to understand and develop novel strategies for managing hypersensitivity. Here, we compared the neural signatures of affective self- and other-touch between adults with ADHD and neurotypical controls (NC).MethodsTwenty-eight adult ADHD participants and 30 age- and gender-matched NC performed a self-other-touch-task during functional magnetic resonance imaging: they stroked their own arm, an object, or were stroked by the experimenter. In addition, tactile detection thresholds and rubber hand illusion (RHI) were measured.ResultsADHD participants had more autistic traits than NC and reported to engage less in interpersonal touch. They also reported to be more sensitive to tactile stimuli. Compared to NC, ADHD participants showed enhanced responses to both the self- and other-touch conditions: stronger deactivation during self-touch in the anterior and posterior insula, and increased activation during other-touch in primary somatosensory cortex. ADHD participants had intact tactile detection thresholds, but were less susceptible to the RHI.ConclusionsUnaltered detection thresholds suggest that peripheral processing is intact, and that hypersensitivity might be driven by central mechanisms. This has clinical implications for managing somatosensory hypersensitivity in ADHD. The more pronounced differentiation between self- and other-touch might indicate a clearer self-other-distinction. This is of interest regarding body ownership perception in both NC and ADHD, and possibly other psychiatric conditions with altered self-experiences, like schizophrenia. A sharper boundary of the own body might relate to deficits in social cognition and tactile hypersensitivity.
|
|
13. |
- de Wit, Harriet, et al.
(author)
-
Does acute stress play a role in the lasting therapeutic effects of psychedelic drugs?
- 2023
-
In: Neuropsychopharmacology. - : SPRINGERNATURE. - 0893-133X .- 1740-634X. ; 48:10, s. 1422-1424
-
Journal article (peer-reviewed)abstract
- Psychedelic drugs, when used in the context of psychotherapy, can produce significant and long-lasting memories with enduring beneficial effects. Yet, the behavioral and neurobiological mechanisms that underlie these beneficial effects remain a mystery. Here, we suggest that both the quality and durability of memories of the drug-facilitated therapeutic experience may be mediated, in part, by the acute stress responses induced by the drugs. It is known that high doses of psychedelic drugs activate autonomic and hormonal stress responses. For evolutionarily adaptive reasons, acute stress is known to i) instill meaning to the immediate context in which it is experienced, and ii) lead to the formation of salient and lasting memories of the events surrounding the stress. Thus, the stress-inducing effect of psychedelic drugs may contribute to the reported sense of meaning, as well as the durability of the memory of the drug experience. When used in a therapeutic context these actions may i) enhance the salience of insights gained during the experience and ii) strengthen the memories formed by these experiences. Future empirical studies will help to determine whether acute stress contributes to the emotional significance and lasting effects of psychedelic-assisted psychotherapy.
|
|
14. |
- Domi, Esi, et al.
(author)
-
Activation of GABA(B) receptors in central amygdala attenuates activity of PKC delta plus neurons and suppresses punishment-resistant alcohol self-administration in rats
- 2023
-
In: Neuropsychopharmacology. - : SPRINGERNATURE. - 0893-133X .- 1740-634X. ; 48, s. 1386-1395
-
Journal article (peer-reviewed)abstract
- Alcohol use despite negative consequences is a core phenomenon of alcohol addiction. We recently used alcohol self-administration that is resistant to footshock punishment as a model of this behavior, and found that activity of PKC delta + GABAergic neurons in the central amygdala (CeA) is a determinant of individual susceptibility for punishment resistance. In the present study, we examined whether activation of GABA(B) receptors in CeA can attenuate the activity of PKC delta + neurons in this region, and whether this will result in suppression of punishment- resistant alcohol self-administration in the minority of rats that show this behavior. Systemic administration of the clinically approved GABA(B) agonist baclofen (1 and 3 mg/kg) dose- dependently reduced punishment-resistant alcohol self-administration. Bilateral microinjections of baclofen into CeA (64 ng in 0.3 mu l/side) reduced the activity of PKC delta + neurons, as measured by Fos expression. This manipulation also selectively suppressed punished alcohol self-administration in punishment-resistant rats. Expression analysis indicated that virtually all CeA PKC delta + neurons express the GABA(B) receptor. Using in vitro electrophysiology, we found that baclofen induced hyperpolarization of CeA neurons, reducing their firing rate in response to depolarizing current injections. Together, our findings provide a potential mechanism that contributes to the clinical efficacy of baclofen in alcohol addiction. Therapeutic use of baclofen itself is limited by problems of tolerance and need for dose escalation. Our findings support a mechanistic rationale for developing novel, improved alcohol addiction medications that target GABA(B) receptors, and that lack these limitations, such as e.g., GABA(B) positive allosteric modulators (PAM:s).
|
|
15. |
- Domi, Esi, et al.
(author)
-
Nicotine increases alcohol self-administration in male rats via a mu-opioid mechanism within the mesolimbic pathway
- 2020
-
In: British Journal of Pharmacology. - : WILEY. - 0007-1188 .- 1476-5381. ; 177:19, s. 4516-4531
-
Journal article (peer-reviewed)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.
|
|
16. |
- Elliott Robinson, J., et al.
(author)
-
Receptor Reserve Moderates Mesolimbic Responses to Opioids in a Humanized Mouse Model of the OPRM1 A118G Polymorphism
- 2015
-
In: Neuropsychopharmacology. - : NATURE PUBLISHING GROUP. - 0893-133X .- 1740-634X. ; 40:11, s. 2614-2622
-
Journal article (peer-reviewed)abstract
- The OPRM1 A118G polymorphism is the most widely studied mu-opioid receptor (MOR) variant. Although its involvement in acute alcohol effects is well characterized, less is known about the extent to which it alters responses to opioids. Prior work has shown that both electrophysiological and analgesic responses to morphine but not to fentanyl are moderated by OPRM1 A118G variation, but the mechanism behind this dissociation is not known. Here we found that humanized mice carrying the 118GG allele (h/mOPRM1-118GG) were less sensitive than h/mOPRM1-118AA littermates to the rewarding effects of morphine and hydrocodone but not those of other opioids measured with intracranial self-stimulation. Reduced morphine reward in 118GG mice was associated with decreased dopamine release in the nucleus accumbens and reduced effects on GABA release in the ventral tegmental area that were not due to changes in drug potency or efficacy in vitro or receptor-binding affinity. Fewer MOR-binding sites were observed in h/mOPRM1-118GG mice, and pharmacological reduction of MOR availability unmasked genotypic differences in fentanyl sensitivity. These findings suggest that the OPRM1 A118G polymorphism decreases sensitivity to low-potency agonists by decreasing receptor reserve without significantly altering receptor function.
|
|
17. |
- Grodin, Erica N., et al.
(author)
-
Neural Correlates of Compulsive Alcohol Seeking in Heavy Drinkers
- 2018
-
In: Biological Psychiatry. - : Elsevier. - 2451-9022. ; 3:12, s. 1022-1031
-
Journal article (peer-reviewed)abstract
- Compulsive alcohol use, the tendency to continue alcohol seeking and taking despite negative consequences, is a hallmark of alcohol use disorder. Preclinical rodent studies have suggested a role for the medial prefrontal cortex, anterior insula, and nucleus accumbens in compulsive alcohol seeking. It is presently unknown whether these findings translate to humans. We used a novel functional magnetic resonance imaging paradigm and tested the hypothesis that heavy drinkers would compulsively seek alcohol despite the risk of an aversive consequence, and that this behavior would be associated with the activity of frontostriatal circuitry.
|
|
18. |
- Hansen, Johan Liseth, et al.
(author)
-
Problematic opioid use among osteoarthritis patients with chronic post-operative pain after joint replacement: analyses from the BISCUITS study
- 2023
-
In: Scandinavian Journal of Pain. - : WALTER DE GRUYTER GMBH. - 1877-8860 .- 1877-8879. ; 23:2, s. 353-363
-
Journal article (peer-reviewed)abstract
- Objectives: Opioids are commonly used to manage pain, despite an increased risk of adverse events and complications when used against recommendations. This register study uses data of osteoarthritis (OA) patients with joint replacement surgery to identify and characterize problematic opioid use (POU) prescription patterns.Methods: The study population included adult patients diagnosed with OA in specialty care undergoing joint replacement surgery in Denmark, Finland, Norway, and Sweden during 1 January 2011 to 31 December 2014. Those with cancer or OA within three years before the first eligible OA diagnosis were excluded. Patients were allocated into six POU cohorts based on dose escalation, frequency, and dosing of prescription opioids post-surgery (definitions were based on guidelines, previous literature, and clinical experience), and matched on age and sex to patients with opioid use, but not in any of the six cohorts. Data on demographics, non-OA pain diagnoses, cardiovascular diseases, psychiatric disorders, and clinical characteristics were used to study patient characteristics and predictors of POU.Results: 13.7% of patients with OA and a hip/knee joint replacement were classified as problematic users and they had more comorbidities and higher pre-surgery doses of opioids than matches. Patients dispensing high doses of opioids pre-surgery dispensed increased doses post-surgery, a pattern not seen among patients prescribed lower doses pre-surgery. Being dispensed 1-4,500 oral morphine equivalents in the year pre-surgery or having a non-OA pain diagnosis was associated with post-surgery POU (OR: 1.44-1.50, and 1.11-1.20, respectively).Conclusions: Based on the discovered POU predictors, the study suggests that prescribers should carefully assess pain management strategies for patients with a history of comorbidities and pre-operative, long-term opioid use. Healthcare units should adopt risk assessment tools and ensure that these patients are followed up closely. The data also demonstrate potential areas for further exploration in improving patient outcomes and trajectories.
|
|
19. |
- Heilig, Markus, 1959-
(author)
-
Alkohol, droger och hjärnan : tro och vetande utifrån modern neurovetenskap
- 2015
-
Book (other academic/artistic)abstract
- Alkohol, droger och hjärnan beskriver framsteg inom hjärnforskningen som gjort det möjligt att bättre förstå alkohol- och drogproblem. Boken är skriven från författarens perspektiv som läkare och forskare och visar hur vetenskapens framsteg pekar ut vägar mot empatisk, rationell behandling som alternativ till moraliserande attityder och vårdideologiska strider.Missbruksproblem är mycket vanliga, och nästan varje familj har erfarenhet av någon som drabbats. Svenskars användningsmönster av alkohol har förändrats. After Work-ölen och mitt-i-veckan-drinken är förhållandevis nya i svensk dryckeskultur, samtidigt som traditionen av tungt helgdrickande finns kvar. Dessa dryckesbeteenden aktualiserar behovet av fördjupad kunskap och vetenskapligt grundade behandlingsmetoder. För att nå dit behöver forskningens resultat nå ut utanför akademiska kretsar.
|
|
20. |
|
|
21. |
- Johnstone, Andrea L., et al.
(author)
-
Dysregulation of the histone demethylase KDM6B in alcohol dependence is associated with epigenetic regulation of inflammatory signaling pathways
- 2021
-
In: Addiction Biology. - : WILEY. - 1355-6215 .- 1369-1600. ; 26:1
-
Journal article (peer-reviewed)abstract
- Epigenetic enzymes oversee long-term changes in gene expression by integrating genetic and environmental cues. While there are hundreds of enzymes that control histone and DNA modifications, their potential roles in substance abuse and alcohol dependence remain underexplored. A few recent studies have suggested that epigenetic processes could underlie transcriptomic and behavioral hallmarks of alcohol addiction. In the present study, we sought to identify epigenetic enzymes in the brain that are dysregulated during protracted abstinence as a consequence of chronic and intermittent alcohol exposure. Through quantitative mRNA expression analysis of over 100 epigenetic enzymes, we identified 11 that are significantly altered in alcohol-dependent rats compared with controls. Follow-up studies of one of these enzymes, the histone demethylase KDM6B, showed that this enzyme exhibits region-specific dysregulation in the prefrontal cortex and nucleus accumbens of alcohol-dependent rats. KDM6B was also upregulated in the human alcoholic brain. Upregulation of KDM6B protein in alcohol-dependent rats was accompanied by a decrease of trimethylation levels at histone H3, lysine 27 (H3K27me3), consistent with the known demethylase specificity of KDM6B. Subsequent epigenetic (chromatin immunoprecipitation [ChIP]-sequencing) analysis showed that alcohol-induced changes in H3K27me3 were significantly enriched at genes in the IL-6 signaling pathway, consistent with the well-characterized role of KDM6B in modulation of inflammatory responses. Knockdown of KDM6B in cultured microglial cells diminished IL-6 induction in response to an inflammatory stimulus. Our findings implicate a novel KDM6B-mediated epigenetic signaling pathway integrated with inflammatory signaling pathways that are known to underlie the development of alcohol addiction.
|
|
22. |
- Karlsson, Camilla, 1977-, et al.
(author)
-
Proinflammatory signaling regulates voluntary alcohol intake and stress-induced consumption after exposure to social defeat stress in mice
- 2017
-
In: Addiction Biology. - : John Wiley & Sons. - 1355-6215 .- 1369-1600. ; 22:5, s. 1279-1288
-
Journal article (peer-reviewed)abstract
- Proinflammatory activity has been postulated to play a role in addictive processes and stress responses, but the underlying mechanisms remain largely unknown. Here, we examined the role of interleukin 1 (IL-1) and tumor necrosis factor-a (TNF-a) in regulation of voluntary alcohol consumption, alcohol reward and stress-induced drinking. Mice with a deletion of the IL-1 receptor I gene (IL-1RI KO) exhibited modestly decreased alcohol consumption. However, IL-1RI deletion affected neither the rewarding properties of alcohol, measured by conditioned place preference (CPP), nor stress-induced drinking induced by social defeat stress. TNF-a signaling can compensate for phenotypic consequences of IL1-RI deletion. We therefore hypothesized that double deletion of both IL-1RI and TNF-1 receptors (TNF-1R) may reveal the role of these pathways in regulation of alcohol intake. Double KOs consumed significantly less alcohol than control mice over a range of alcohol concentrations. The combined deletion of TNF-1R and IL-1RI did not influence alcohol reward, but did prevent increased alcohol consumption resulting from exposure to repeated bouts of social defeat stress. Taken together, these data indicate that IL-1RI and TNF-1R contribute to regulation of stress-induced, negatively reinforced drinking perhaps through overlapping signaling events downstream of these receptors, while leaving rewarding properties of alcohol largely unaffected.
|
|
23. |
- Karlsson, Hanna, 1989-
(author)
-
From social drinking to alcohol addiction : Decision making and its neural substrates along a spectrum from social drinking to alcohol addiction
- 2024
-
Doctoral thesis (other academic/artistic)abstract
- For a minority of alcohol users, the initial sip of alcohol marks the start of a life-threatening process. This thesis studies cognitive mechanisms pertinent to alcohol addiction and its development, using a spectrum of individuals that range from healthy social drinkers, through people with hazardous use, to those suffering from alcohol addiction. Decision making can be altered in addiction, but less is known on the direct pharmacodynamic effects of alcohol intake in healthy people. Study 1 addressed decision making under the effects of moderate alcohol intoxication in healthy social drinkers using established behavioral economics tasks. The investigated processes encompassed both personal and social aspects of decision making. Within the personal domain, impulsivity and risk taking were investigated, while in the social domain, prosocial attitudes along with moral judgment were assessed. Moderate alcohol intoxication was found to impact only the social domain, leading to increased prosocial and utilitarian behaviors, but did not affect measures of impulsivity. Choosing alcohol over other natural rewards despite negative consequences is a central phenomenon of alcohol addiction. Two studies of this thesis investigated choice preference for alcohol compared to snack, using a cost manipulation paradigm, in light and heavy drinkers. Study 2 was a laboratory experiment whereas Study 3 was an imaging experiment for characterization of neural substrates. Cost was an important predictor of choice, as in both groups, alcohol choice was sensitive to cost in a parametric manner. This was mirrored in the brain by activity in value-based and salience regions, including orbitofrontal cortex and insula. In Study 2 we found that heavy drinkers showed generally higher alcohol choice preference and attenuated cost sensitivity. Failure to replicate this finding in Study 3, was possibly due to the artificial scanner environment. Craving is a key component in the cycle of addiction and a determinant of relapse, making it an important target for treatment interventions. Study 4 was a randomized sham-controlled trial using repetitive transcranial magnetic stimulation (rTMS) targeting the insula as a method to reduce craving and alcohol use in people suffering from alcohol addiction. An overall decrease in alcohol consumption and craving were seen, but did not differ between sham stimulation and rTMS targeting the insula. In summary, this thesis provides some insights into cognitive mechanisms related to alcohol addiction and processes that may be implicated in its development. During a moderate acute alcohol intoxication in healthy social drinkers, social decision-making is influenced, leading to increased utilitarian and altruistic behaviors. Thus, deficits in prosocial behaviors in people with alcohol addiction are unlikely to result from direct pharmacodynamic effects of alcohol, but are rather likely to reflect a selection of vulnerable individuals, consequences of the addictive process, or both. In individuals at risk of developing alcohol addiction, the sensitivity to the costs associated with choosing alcohol over an alternative reward is largely preserved, though it might be reduced compared to light, non-problem drinkers. Modulation of the insula cortex with TMS was not successful in decreasing alcohol use in individuals with alcohol addiction.
|
|
24. |
- Lee, Mary R., et al.
(author)
-
Corticotropin-Releasing Factor receptor 1 (CRF1) antagonism in patients with alcohol use disorder and high anxiety levels: effect on neural response during Trier Social Stress Test video feedback
- 2023
-
In: Neuropsychopharmacology. - : SPRINGERNATURE. - 0893-133X .- 1740-634X. ; 48:5, s. 816-820
-
Journal article (peer-reviewed)abstract
- In preclinical models of alcohol use disorder, the corticotropin-releasing factor (CRF) receptor is upregulated, particularly in the extended amygdala. This upregulation is thought to play a role in stress-induced relapse to drinking by a mechanism that is independent of the hypothalamic-pituitary-adrenal axis. As part of a double-blind, placebo-controlled clinical study with pexacerfont, a selective, orally available, and brain-penetrant CRF1 receptor antagonist which has anti-anxiety effects in preclinical studies, we examined the effect of pexacerfont on the neural response to a social stress task adapted to fMRI. Subjects were 39 individuals (4 women) with high trait anxiety and moderate to severe alcohol use disorder randomized to receive pexacerfont or placebo. The task involved feedback of videoclips of an individual performing the Trier Social Stress Test. Pexacerfont had no effect on the neural response to self-observation under stress. The neural response to viewing oneself under stress vs an unknown other under stress activated prefrontal brain regions including insula, inferior frontal gyrus as well as medial, superior frontal gyri. These regions of activation overlap with those found in studies using similar paradigms. Potential applications of this task to probe neurocircuitry that is disrupted in addiction is discussed.
|
|
25. |
- Lindell, S. G., et al.
(author)
-
Intermittent Access to Ethanol Induces Escalated Alcohol Consumption in Primates
- 2017
-
In: Journal of addictive behaviors, therapy and rehabilitation. - : SciTechnol. - 2324-9005. ; 6:1
-
Journal article (peer-reviewed)abstract
- Escalation of voluntary alcohol drinking is characteristic of alcohol addiction and can be induced in rodents using intermittent access to alcohol. This model has been used to evaluate candidate therapeutics, but key systems involved in the transition into alcohol addiction, such as CRF, differ in their organization between rodents and primates. We examined the ability of an intermittent access schedule to induce escalation of voluntary alcohol drinking in non-human primates and used this model to assess the role of corticotropin releasing hormone (CRF) signaling in this process.
|
|
26. |
- Ljungvall, Hanna, et al.
(author)
-
Reliability of the Addiction Severity Index self-report form (ASI-SR) : a self-administered questionnaire based on the Addiction Severity Index composite score domains
- 2020
-
In: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 74:1, s. 9-15
-
Journal article (peer-reviewed)abstract
- Objectives: The Addiction Severity Index (ASI) is a standardized interview used to assess problems associated with substance use. Although widely used, the time required for the interview remains an obstacle to its acceptance in many clinical settings. We examined if a self-administered questionnaire based on the composite score (CS) items, the ASI Self-Report form (ASI-SR), offers a reliable alternative to the ASI in assessing current substance use and related problems.Methods:Participants were 59 treatment seeking individuals entering outpatient programs at the Addiction Psychiatric Clinic at Uppsala University Hospital who were assessed with Swedish versions of the ASI and ASI-SR. Agreement between the ASI interview's CS and ASI-SR's CS was evaluated on the individual basis by intraclass correlation analysis (ICC) and on group level with the Wilcoxon signed rank test. Reliability and internal consistency were evaluated using Cronbach's alpha.Results:For 6 out of 7 CS domains, the ICC for the ASI interview and ASI-SR were good to excellent. Internal consistency was acceptable for 6 out of 7 CS domains on the ASI interview and for 5 out of 7 CS domains on the ASI-SR.Conclusions:The present study suggests that the ASI-SR is a reliable alternative to the ASI interview for assessing current patient functioning and evaluation of problems related to alcohol and drug use.
|
|
27. |
- Löfberg, Andreas, 1987-, et al.
(author)
-
Assessing Childhood Maltreatment Exposure in Patients Without and With a Diagnosis of Substance Use Disorder
- 2023
-
In: Journal of addiction medicine. - : Wolters Kluwer. - 1932-0620 .- 1935-3227. ; 17:3, s. 263-270
-
Journal article (peer-reviewed)abstract
- Objectives: Childhood maltreatment (CM), widely held as a risk factor for substance use disorders (SUDs), is commonly assessed using the Childhood Trauma Questionnaire (CTQ). Retrospective self-reports are, however, potentially subject to bias. We used a unique patient sample with prospectively documented CM to examine the performance of the CTQ and how this is affected by the presence of SUD.Methods: Analysis was based on a total of 104 individuals. Subjects with prospectively recorded CM were identified from a specialized childhood trauma unit in Linköping, Sweden (n = 55; 31 with SUD, 61% females; 24 without SUD, 71% females). Clinical controls had SUD but no CM (n = 25, 48% females). Healthy controls had neither SUD nor CM (n = 24, 54% females). We analyzed the agreement between retrospective CTQ scores and prospectively documented CM by κ analysis and assessed the performance of the CTQ to identify CM exposure using receiver operating characteristic (ROC) analysis.Results: Agreement between prospectively and retrospectively recorded CM exposure was poor for sexual abuse (36.6%, Cohen κ = 0.32, P = 0.008) and physical abuse (67.3%, κ = 0.35, P = 0.007). Overall CTQ performance was fair (ROC: area under the ROC curve = 0.78, optimal cutoff = 36.5, sensitivity = 0.65, specificity = 0.75). However, performance was excellent in the absence of SUD (area under the ROC curve = 0.93, cutoff = 32.0, sensitivity = 0.88, specificity = 0.88), but poor in participants with lifetime SUD (area under the ROC curve = 0.62, cutoff = 42.0, sensitivity = 0.60, specificity = 0.36).Conclusions: These data support the CTQ as a tool to assess CM exposure but suggest that it may be less useful in patients with SUD.
|
|
28. |
- Mayo, Leah, et al.
(author)
-
Elevated Anandamide, Enhanced Recall of Fear Extinction, and Attenuated Stress Responses Following Inhibition of Fatty Acid Amide Hydrolase: A Randomized, Controlled Experimental Medicine Trial
- 2020
-
In: Biological Psychiatry. - : ELSEVIER SCIENCE INC. - 0006-3223 .- 1873-2402. ; 87:6, s. 538-547
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Posttraumatic stress disorder, an area of large unmet medical needs, is characterized by persistence of fear memories and maladaptive stress responses. In rodents, elevation of the endocannabinoid anandamide due to inhibition of fatty acid amide hydrolase (FAAH) facilitates fear extinction and protects against the anxiogenic effects of stress. We recently reported that elevated anandamide levels in people homozygous for a loss-of-function FAAH mutation are associated with a similar phenotype, suggesting a translational validity of the preclinical findings. METHODS: In this double-blind, placebo-controlled experimental medicine study, healthy adults were randomized to an FAAH inhibitor (PF-04457845, 4 mg orally, once daily; n = 16) or placebo (n = 29) for 10 days. On days 9 and 10, participants completed a task battery assessing psychophysiological indices of fear learning, stress reactivity, and stress-induced affective responses. RESULTS: FAAH inhibition produced a 10-fold increase in baseline anandamide. This was associated with potentiated recall of fear extinction memory when tested 24 hours after extinction training. FAAH inhibition also attenuated autonomic stress reactivity, assessed via electrodermal activity, and protected against stress-induced negative affect, measured via facial electromyography. CONCLUSIONS: Our data provide preliminary human evidence that FAAH inhibition can improve the recall of fear extinction memories and attenuate the anxiogenic effects of stress, in a direct translation of rodent findings. The beneficial effects of FAAH inhibition on fear extinction, as well as stress- and affect-related behaviors, provide a strong rationale for developing this drug class as a treatment for posttraumatic stress disorder.
|
|
29. |
- Mayo, Leah M., 1987-, et al.
(author)
-
Protective effects of elevated anandamide on stress and fear-related behaviors : translational evidence from humans and mice
- 2020
-
In: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 25:5, s. 993-1005
-
Journal article (peer-reviewed)abstract
- Post-traumatic stress disorder (PTSD) is a common, debilitating condition with limited treatment options. Extinction of fear memories through prolonged exposure therapy, the primary evidence-based behavioral treatment for PTSD, has only partial efficacy. In mice, pharmacological inhibition of fatty acid amide hydrolase (FAAH) produces elevated levels of anandamide (AEA) and promotes fear extinction, suggesting that FAAH inhibitors may aid fear extinction-based treatments. A human FAAH 385C-greater thanA substitution encodes an FAAH enzyme with reduced catabolic efficacy. Individuals homozygous for the FAAH 385A allele may therefore offer a genetic model to evaluate the impact of elevations in AEA signaling in humans, helping to inform whether FAAH inhibitors have the potential to facilitate fear extinction therapy for PTSD. To overcome the challenge posed by low frequency of the AA genotype (appr. 5%), we prospectively genotyped 423 individuals to examine the balanced groups of CC, AC, and AA individuals (n = 25/group). Consistent with its loss-of-function nature, the A allele was dose dependently associated with elevated basal AEA levels, facilitated fear extinction, and enhanced the extinction recall. Moreover, the A-allele homozygotes were protected against stress-induced decreases in AEA and negative emotional consequences of stress. In a humanized mouse model, AA homozygous mice were similarly protected against stress-induced decreases in AEA, both in the periphery, and also in the amygdala and prefrontal cortex, brain structures critically involved in fear extinction and regulation of stress responses. Collectively, these data suggest that AEA signaling can temper aspects of the stress response and that FAAH inhibition may aid the treatment for stress-related psychiatric disorders, such as PTSD.
|
|
30. |
- Muench, Christine, et al.
(author)
-
Fear conditioning and extinction in alcohol dependence: Evidence for abnormal amygdala reactivity
- 2021
-
In: Addiction Biology. - : WILEY. - 1355-6215 .- 1369-1600. ; 26:1
-
Journal article (peer-reviewed)abstract
- Fear conditioning and extinction (FCE) are vital processes in adaptive emotion regulation and disrupted in anxiety disorders. Despite substantial comorbidity between alcohol dependence (ALC) and anxiety disorders and reports of altered negative emotion processing in ALC, neural correlates of FCE in this clinical population remain unknown. Here, we used a 2-day fear learning paradigm in 43 healthy participants and 43 individuals with ALC at the National Institutes of Health. Main outcomes of this multimodal study included structural and functional brain magnetic resonance imaging, clinical measures, as well as skin conductance responses (SCRs) to confirm differential conditioning. Successful FCE was demonstrated across participants by differential SCRs in the conditioning phase and no difference in SCRs to the conditioned stimuli in the extinction phase. The ALC group showed significantly reduced blood oxygenation level-dependent responses in the right amygdala during conditioning (Cohens d = .89, P-(FWE) = .037) and in the left amygdala during fear renewal (Cohens d = .68, P-(FWE) = .039). Right amygdala activation during conditioning was significantly correlated with ALC severity (r = .39, P-(Bonferroni) = .009), depressive symptoms (r = .37, P-(Bonferroni) = .015), trait anxiety (r = .41, P-(Bonferroni) = .006), and perceived stress (r = .45, P-(Bonferroni) = .002). Our data suggest that individuals with ALC have dysregulated fear learning, in particular, dysregulated neural activation patterns, in the amygdala. Furthermore, amygdala activation during fear conditioning was associated with ALC-related clinical measures. The FCE paradigm may be a promising tool to investigate structures involved in negative affect regulation, which might inform the development of novel treatment approaches for ALC.
|
|
31. |
- Paul, Elisabeth, 1991-, et al.
(author)
-
Peripheral and central kynurenine pathway abnormalities in major depression
- 2022
-
In: Brain, behavior, and immunity. - : Academic Press Inc - Elsevier Science. - 0889-1591 .- 1090-2139. ; 101, s. 136-145
-
Journal article (peer-reviewed)abstract
- Considerable data relate major depressive disorder (MDD) with aberrant immune system functioning. Pro inflammatory cytokines facilitate metabolism of tryptophan along the kynurenine pathway (KP) putatively resulting in reduced neuroprotective and increased neurotoxic KP metabolites in MDD, in addition to modulating metabolic and immune function. This central nervous system hypothesis has, however, only been tested in the periphery. Here, we measured KP-metabolite levels in both plasma and cerebrospinal fluid (CSF) of depressed patients (n = 63/36 respectively) and healthy controls (n = 48/33). Further, we assessed the relation between KP abnormalities and brain-structure volumes, as well as body mass index (BMI), an index of metabolic disturbance associated with atypical depression. Plasma levels of picolinic acid (PIC), the kynurenic/quinolinic acid ratio (KYNA/QUIN), and PIC/QUIN were lower in MDD, but QUIN levels were increased. In the CSF, we found lower PIC in MDD. Confirming previous work, MDD patients had lower hippocampal, and amygdalar volumes. Hippocampal and amygdalar volumes were correlated positively with plasma KYNA/QUIN ratio in MDD patients. BMI was increased in the MDD group relative to the control group. Moreover, BMI was inversely correlated with plasma and CSF PIC and PIC/QUIN, and positively correlated with plasma QUIN levels in MDD. Our results partially confirm previous peripheral KP findings and extend them to the CSF in MDD. We present the novel finding that abnormalities in KP metabolites are related to metabolic disturbances in depression, but the relation between KP metabolites and depression-associated brain atrophy might not be as direct as previously hypothesized.
|
|
32. |
- Peng, Shi-Yu, et al.
(author)
-
Reduced motor cortex GABABR function following chronic alcohol exposure
- 2021
-
In: Molecular Psychiatry. - : SPRINGERNATURE. - 1359-4184 .- 1476-5578. ; 26:2, s. 383-395
-
Journal article (peer-reviewed)abstract
- The GABA(B) receptor (GABA(B)R) agonist baclofen has been used to treat alcohol and several other substance use disorders (AUD/SUD), yet its underlying neural mechanism remains unclear. The present study aimed to investigate cortical GABA(B)R dynamics following chronic alcohol exposure. Ex vivo brain slice recordings from mice chronically exposed to alcohol revealed a reduction in GABA(B)R-mediated currents, as well as a decrease of GABA(B1/2)R and G-protein-coupled inwardly rectifying potassium channel 2 (GIRK2) activities in the motor cortex. Moreover, our data indicated that these alterations could be attributed to dephosphorylation at the site of serine 783 (ser-783) in GABA(B2) subunit, which regulates the surface expression of GABA(B)R. Furthermore, a human study using paired-pulse-transcranial magnetic stimulation (TMS) analysis further demonstrated a reduced cortical inhibition mediated by GABA(B)R in patients with AUD. Our findings provide the first evidence that chronic alcohol exposure is associated with significantly impaired cortical GABA(B)R function. The ability to promote GABA(B)R signaling may account for the therapeutic efficacy of baclofen in AUD.
|
|
33. |
- Perini, Irene, 1983-, et al.
(author)
-
Repetitive transcranial magnetic stimulation targeting the insular cortex for reduction of heavy drinking in treatment-seeking alcohol-dependent subjects: a randomized controlled trial
- 2020
-
In: Neuropsychopharmacology. - : Springer Nature. - 0893-133X .- 1740-634X. ; 45:5, s. 842-850
-
Journal article (peer-reviewed)abstract
- Insula responses to drug cues are correlated with cravings, and lesions in this area reduce nicotine seeking. Here, we investigated the potential efficacy of repetitive transcranial magnetic stimulation (rTMS) targeting the insula in alcohol addiction. Treatment-seeking alcohol-dependent patients (Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition; N = 56) participated in this double-blind, sham-controlled, randomized trial. Participants received 10 Hz rTMS or sham using an H8 coil, 5 days a week for 3 weeks. Stimulation targeted insular cortex and overlaying regions bilaterally, while excluding anterior prefrontal areas. Craving and self-reported as well as biomarker-based drinking measures were collected at baseline, during treatment, and through 12 weeks. Resting-state magnetic resonance imaging (rsMRI) data were collected before and after treatment. Task-based MRI was used to probe brain correlates of reward processing, affective responses, and alcohol following completion of treatment. A marked overall decrease in craving and drinking measures was observed during treatment, but did not differ between rTMS or sham stimulation. Both groups equally increased their alcohol use following completion of treatment and through the 12-week follow-up. Analysis using seeds in the insula identified differences in resting-state connectivity between active and sham groups at completion of treatment, potentially indicating an ability of treatment to modify insula function. However, while each task robustly replicated brain responses established in the literature, no effects of rTMS were found. Collectively, this study does not support efficacy of rTMS targeting the insula in alcohol addiction.
|
|
34. |
- Perini, Irene, 1983-, et al.
(author)
-
Resilience to substance use disorder following childhood maltreatment: association with peripheral biomarkers of endocannabinoid function and neural indices of emotion regulation
- 2023
-
In: Molecular Psychiatry. - : SPRINGERNATURE. - 1359-4184 .- 1476-5578. ; :6, s. 2563-2571
-
Journal article (peer-reviewed)abstract
- Childhood maltreatment (CM) is a risk factor for substance use disorders (SUD) in adulthood. Understanding the mechanisms by which people are susceptible or resilient to developing SUD after exposure to CM is important for improving intervention. This case-control study investigated the impact of prospectively assessed CM on biomarkers of endocannabinoid function and emotion regulation in relation to the susceptibility or resilience to developing SUD. Four groups were defined across the dimensions of CM and lifetime SUD (N = 101 in total). After screening, participants completed two experimental sessions on separate days, aimed at assessing the behavioral, physiological, and neural mechanisms involved in emotion regulation. In the first session, participants engaged in tasks assessing biochemical (i.e., cortisol, endocannabinoids), behavioral, and psychophysiological indices of stress and affective reactivity. During the second session, the behavioral and brain mechanisms associated with emotion regulation and negative affect were investigated using magnetic resonance imaging. CM-exposed adults who did not develop SUD, operationally defined as resilient to developing SUD, had higher peripheral levels of the endocannabinoid anandamide at baseline and during stress exposure, compared to controls. Similarly, this group had increased activity in salience and emotion regulation regions in task-based measures of emotion regulation compared to controls, and CM-exposed adults with lifetime SUD. At rest, the resilient group also showed significantly greater negative connectivity between ventromedial prefrontal cortex and anterior insula compared to controls and CM-exposed adults with lifetime SUD. Collectively, these peripheral and central findings point to mechanisms of potential resilience to developing SUD after documented CM exposure.
|
|
35. |
- Perini, Irene, 1983-, et al.
(author)
-
Social Acts and Anticipation of Social Feedback
- 2022
-
In: Neuroscience of Social Stress. - Cham : Springer. - 9783031042560 - 9783031042553 ; , s. 393-416
-
Book chapter (other academic/artistic)abstract
- Socialization happens so regularly in humans that it can be perceived as an effortless activity. However, it reflects a sophisticated behavior, pervaded by anticipation and emotion. The fast-paced social interplay, strongly mediated by facial expressions, can be considered one of the most frequent high-order motor acts within the human behavioral repertoire. The ability to adequately process social feedback is critical for appropriate socialization and affects well-being. The social difficulties often observed in psychiatric patients highlight the link between mental health and successful socialization and the importance of characterizing the behavioral and neural mechanisms of social interaction. This chapter will present some cross-species evidence on the cortical regions engaged during social interactions including facial expressions, and the impact of induced or perceived social stress on the experience of social interactions.
|
|
36. |
- Persson, Emil, 1982-, et al.
(author)
-
Using quantitative trait in adults with ADHD to test predictions of dual-process theory
- 2020
-
In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
-
Journal article (peer-reviewed)abstract
- Dual-process theory is a widely utilized modelling tool in the behavioral sciences. It conceptualizes decision-making as an interaction between two types of cognitive processes, some of them fast and intuitive, others slow and reflective. We make a novel contribution to this literature by exploring differences between adults with clinically diagnosed ADHD and healthy controls for a wide range of behaviors. Given the clinical picture and nature of ADHD symptoms, we had a strong a priori reason to expect differences in intuitive vs reflective processing; and thus an unusually strong case for testing the predictions of dual-process theory. We found mixed results, with overall weaker effects than expected, except for risk taking, where individuals with ADHD showed increased domain sensitivity for gains vs losses. Some of our predictions were supported by the data but other patterns are more difficult to reconcile with theory. On balance, our results provide only limited empirical support for using dual-process theory to understand basic social and economic decision-making.
|
|
37. |
- Petrella, Michele, et al.
(author)
-
Pharmacological blockage of NOP receptors decreases ventral tegmental area dopamine neuronal activity through GABAB receptor-mediated mechanism
- 2024
-
In: Neuropharmacology. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0028-3908 .- 1873-7064. ; 248
-
Journal article (peer-reviewed)abstract
- The Nociceptin/Orphanin FQ (N/OFQ) peptide and its receptor NOP are highly expressed within several regions of the mesolimbic system, including the ventral tegmental area (VTA). Evidence indicates that the N/OFQ-NOP receptor system is involved in reward processing and historically it has been proposed that activation of NOP receptors attenuates the motivation for substances of abuse. However, recent findings demonstrated that drug self -administration and relapse to drug -seeking are also attenuated after administration of NOP receptor antagonists. Here, to shed light on the mechanisms through which NOP receptor blockers modulate these processes, we utilized ex vivo patch -clamp recordings to investigate the effect of the selective NOP receptor antagonist LY2817412 on VTA dopaminergic (DA) function in male rats. Results showed that, similar to the endogenous NOP receptor agonist N/OFQ, LY2817412 reduced the spontaneous basal firing discharge of VTA DA neurons. Consistently, we found that NOP receptors are expressed both in VTA DA and GABA cells and that LY2817412 slice perfusion increased GABA release onto VTA DA cells. Finally, in the attempt to dissect the role of postsynaptic and presynaptic NOP receptors, we tested the effect of N/OFQ and LY2817412 in the presence of GABA receptors blockers. Results showed that the effect of LY2817412 was abolished following pretreatment with GABABR, but not GABAAR, blockers. Conversely, inhibition of DA neuronal activity by N/OFQ was unaffected by blockade of GABA receptors. Altogether, these results suggest that both NOP receptor agonists and antagonists can decrease VTA DA neuronal activity, but through distinct mechanisms of action. The effect of NOP receptor antagonists occurs through a GABABR-mediated mechanism while NOP receptor agonists seem to act via a direct effect on VTA DA neurons.
|
|
38. |
- Pietrzak, Michal, 1987-, et al.
(author)
-
Ghrelin decreases sensitivity to negative feedback and increases prediction-error related caudate activity in humans, a randomized controlled trial
- 2024
-
In: Neuropsychopharmacology. - : Springer Science+Business Media B.V.. - 0893-133X .- 1740-634X. ; 49, s. 1042-1049
-
Journal article (peer-reviewed)abstract
- The stomach-derived hormone ghrelin plays not only a role in feeding, starvation, and survival, but it has been suggested to also be involved in the stress response, in neuropsychiatric conditions, and in alcohol and drug use disorders. Mechanisms related to reward processing might mediate ghrelin's broader effects on complex behaviors, as indicated by animal studies and mostly correlative human studies. Here, using a within-subject double-blind placebo-controlled design with intravenous ghrelin infusion in healthy volunteers (n = 30), we tested whether ghrelin alters sensitivity to reward and punishment in a reward learning task. Parameters were derived from a computational model of participants' task behavior. The reversal learning task with monetary rewards was performed during functional brain imaging to investigate ghrelin effects on brain signals related to reward prediction errors. Compared to placebo, ghrelin decreased punishment sensitivity (t = -2.448, p = 0.021), while reward sensitivity was unaltered (t = 0.8, p = 0.43). We furthermore found increased prediction-error related activity in the dorsal striatum during ghrelin administration (region of interest analysis: t-values >= 4.21, p-values <= 0.044). Our results support a role for ghrelin in reward processing that extends beyond food-related rewards. Reduced sensitivity to negative outcomes and increased processing of prediction errors may be beneficial for food foraging when hungry but could also relate to increased risk taking and impulsivity in the broader context of addictive behaviors.
|
|
39. |
|
|
40. |
- Sangchooli, Arshiya, et al.
(author)
-
Parameter Space and Potential for Biomarker Development in 25 Years of fMRI Drug Cue Reactivity
- 2024
-
In: JAMA psychiatry. - : AMER MEDICAL ASSOC. - 2168-6238 .- 2168-622X.
-
Research review (peer-reviewed)abstract
- Importance In the last 25 years, functional magnetic resonance imaging drug cue reactivity (FDCR) studies have characterized some core aspects in the neurobiology of drug addiction. However, no FDCR-derived biomarkers have been approved for treatment development or clinical adoption. Traversing this translational gap requires a systematic assessment of the FDCR literature evidence, its heterogeneity, and an evaluation of possible clinical uses of FDCR-derived biomarkers. Objective To summarize the state of the field of FDCR, assess their potential for biomarker development, and outline a clear process for biomarker qualification to guide future research and validation efforts. Evidence Review The PubMed and Medline databases were searched for every original FDCR investigation published from database inception until December 2022. Collected data covered study design, participant characteristics, FDCR task design, and whether each study provided evidence that might potentially help develop susceptibility, diagnostic, response, prognostic, predictive, or severity biomarkers for 1 or more addictive disorders. Findings There were 415 FDCR studies published between 1998 and 2022. Most focused on nicotine (122 [29.6%]), alcohol (120 [29.2%]), or cocaine (46 [11.1%]), and most used visual cues (354 [85.3%]). Together, these studies recruited 19 311 participants, including 13 812 individuals with past or current substance use disorders. Most studies could potentially support biomarker development, including diagnostic (143 [32.7%]), treatment response (141 [32.3%]), severity (84 [19.2%]), prognostic (30 [6.9%]), predictive (25 [5.7%]), monitoring (12 [2.7%]), and susceptibility (2 [0.5%]) biomarkers. A total of 155 interventional studies used FDCR, mostly to investigate pharmacological (67 [43.2%]) or cognitive/behavioral (51 [32.9%]) interventions; 141 studies used FDCR as a response measure, of which 125 (88.7%) reported significant interventional FDCR alterations; and 25 studies used FDCR as an intervention outcome predictor, with 24 (96%) finding significant associations between FDCR markers and treatment outcomes. Conclusions and Relevance Based on this systematic review and the proposed biomarker development framework, there is a pathway for the development and regulatory qualification of FDCR-based biomarkers of addiction and recovery. Further validation could support the use of FDCR-derived measures, potentially accelerating treatment development and improving diagnostic, prognostic, and predictive clinical judgments.
|
|
41. |
|
|
42. |
- Thorsell, Annika, et al.
(author)
-
Cationic lipid-mediated delivery and expression of prepro-neuropeptide Y cDNA after intraventricular administration in rat : feasibility and limitations.
- 1996
-
In: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 61:3, s. 205-211
-
Journal article (peer-reviewed)abstract
- The utility of in vivo lipofection for delivery and expression of a neuropeptide gene in the adult rat brain was explored. Prepro-neuropeptide Y (NPY) cDNA was cloned into the episomal eucaryotic expression vector pCEP4. This construct was complexed to lipofectamine or lipofectin. Complexed DNA was injected into the lateral ventricles of adult rats. Brains were removed for analysis following various time intervals. Polymerase chain reaction (PCR) reactions were designed for specific detection of endogenous and vector derived NPY sequence, respectively. PCR of DNA preparations from 5 major brain regions (frontal and parietal cortex, striatum, hypothalamus, brain stem) demonstrated presence of vector DNA up to 1 month (longest interval studied) in all brain regions. Reverse-transcription (RT-) PCR of DNase treated RNA-preparations from brain tissue demonstrated presence of both vector-derived and endogenous NPY mRNA in treated animals, while only endogenous mRNA was detected in controls. In situ hybridization histochemistry indicated scattered patches of vector uptake into tissue in the vicinity of the CSF compartment, but not into deeper located structures. Weight gain was not affected, indicating that the expression levels achieved may not be sufficient to play a functional role, and/or may need to be targeted to specific brain areas. These findings suggest a potential for cationic lipid mediated gene transfer in the brain as an experimental tool and as a possible future therapeutic principle, but also indicate the need for optimization of delivery strategies in order to achieve functionally relevant expression levels.
|
|
43. |
- Van Hedger, Kathryne, et al.
(author)
-
Neural responses to cues paired with methamphetamine in healthy volunteers
- 2018
-
In: Neuropsychopharmacology. - : Nature Publishing Group. - 0893-133X .- 1740-634X. ; 43:8, s. 1732-1737
-
Journal article (peer-reviewed)abstract
- Drug cues, or conditioned responses to stimuli paired with drugs, are widely believed to promote drug use. The acquisition of these conditioned responses has been well characterized in laboratory animals: neutral stimuli paired with drugs elicit conditioned responses resembling the motivational and incentive properties of the drug itself. However, few studies have examined acquisition of conditioning, or the nature of the conditioned response, in humans. In this study, we used fMRI to examine neural responses to stimuli that had been paired with methamphetamine or placebo in healthy young adults. Participants first underwent four conditioning sessions in which visual-auditory stimuli were paired with either methamphetamine (20 mg, oral) or placebo. Then on a drug-free test day, the stimuli were presented during an fMRI scan to assess neural responses to the stimuli. We hypothesized that the stimuli would elicit drug-like brain activity, especially in regions related to reward. Instead, we found that the methamphetamine-paired stimuli, compared to placebo-paired stimuli, produced greater activation in regions related to visual and auditory processing, consistent with the drugs unconditioned effects on sensory processing. This is the first study to demonstrate conditioned neural responses to drug-paired stimuli after just two pairings of methamphetamine in healthy adults. The study also illustrates that conditioned responses may develop to unexpected components of the drugs effects.
|
|
44. |
- Zallar, L J, et al.
(author)
-
Development and initial characterization of a novel ghrelin receptor CRISPR/Cas9 knockout wistar rat model
- 2019
-
In: International Journal of Obesity. - : Nature Pub. Group. - 0307-0565 .- 1476-5497. ; 43:2, s. 344-354
-
Journal article (peer-reviewed)abstract
- Ghrelin, a stomach-derived hormone implicated in numerous behaviors including feeding, reward, stress, and addictive behaviors, acts by binding to the growth hormone secretagogue receptor (GHSR). Here, we present the development, verification, and initial characterization of a novel GHSR knockout (KO) Wistar rat model created with CRISPR genome editing.
|
|