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Zhu H, Yang X, Zhao Y. Recent Advances in Current Uptake Situation, Metabolic and Nutritional Characteristics, Health, and Safety of Dietary Tryptophan. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:6787-6802. [PMID: 38512048 DOI: 10.1021/acs.jafc.3c06419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Tryptophan (Trp) is an essential amino acid which is unable to be synthesized in the body. Main sources of Trp are uptake of foods such as oats and bananas. In this review, we describe the status of current dietary consumption, metabolic pathways and nutritional characteristics of Trp, as well as its ingestion and downstream metabolites for maintaining body health and safety. This review also summarizes the recent advances in Trp metabolism, particularly the 5-HT, KYN, and AhR activation pathways, revealing that its endogenous host metabolites are not only differentially affected in the body but also are closely linked to health. More attention should be paid to targeting its specific metabolic pathways and utilizing food molecules and probiotics for manipulating Trp metabolism. However, the complexity of microbiota-host interactions requires further exploration to precisely refine targets for innovating the gut microbiota-targeted diagnostic approaches and informing subsequent studies and targeted treatments of diseases.
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Affiliation(s)
- Haoyan Zhu
- Key Laboratory of the Ministry of Education for Medicinal Resource and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Xingbin Yang
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, and Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710119, China
| | - Yan Zhao
- Key Laboratory of the Ministry of Education for Medicinal Resource and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
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Gilger MD, Hellrung L, Neukam PT, Kroemer NB, Nebe S, Pooseh S, Deza-Lougovski YI, Smolka MN. Arbitration between model-free and model-based control is not affected by transient changes in tonic serotonin levels. J Psychopharmacol 2024; 38:178-187. [PMID: 38151862 PMCID: PMC10863371 DOI: 10.1177/02698811231216325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
BACKGROUND Serotonin has been suggested to modulate decision-making by influencing the arbitration between model-based and model-free control. Disruptions in these control mechanisms are involved in mental disorders such as drug dependence or obsessive-compulsive disorder. While previous reports indicate that lower brain serotonin levels reduce model-based control, it remains unknown whether increases in serotonergic availability might thus increase model-based control. Moreover, the mediating neural mechanisms have not been studied yet. AIM The first aim of this study was to investigate whether increased/decreased tonic serotonin levels affect the arbitration between model-free and model-based control. Second, we aimed to identify the underlying neural processes. METHODS We employed a sequential two-stage Markov decision-task and measured brain responses during functional magnetic resonance imaging in 98 participants in a randomized, double-blind cross-over within-subject design. To investigate the influence of serotonin on the balance between model-free and model-based control, we used a tryptophan intervention with three intervention levels (loading, balanced, depletion). We hypothesized that model-based behaviour would increase with higher serotonin levels. RESULTS We found evidence that neither model-free nor model-based control were affected by changes in tonic serotonin levels. Furthermore, our tryptophan intervention did not elicit relevant changes in Blood-Oxygenation-Level Dependent activity.
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Affiliation(s)
- Maximilian D. Gilger
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
| | - Lydia Hellrung
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland
| | - Philipp T. Neukam
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- Depression and Anxiety Center for Discovery and Treatment, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Nils B. Kroemer
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- Section of Medical Psychology, Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Bonn, Bonn, Germany
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health, University of Tübingen, Tübingen, Germany
- German Center for Mental Health (DZPG), Tübingen, Germany
| | - Stephan Nebe
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland
| | - Shakoor Pooseh
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- Freiburg Center for Data Analysis and Modelling, Institute of Physics, University of Freiburg, Freiburg, Germany
| | - Yacila I. Deza-Lougovski
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- Institute of Psychology, University of the Bundeswehr München, Neubiberg, Germany
| | - Michael N. Smolka
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
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No effects of acute tryptophan depletion on anxiety or mood in weight-recovered female patients with anorexia nervosa. Eur Arch Psychiatry Clin Neurosci 2023; 273:209-217. [PMID: 35511296 PMCID: PMC9957824 DOI: 10.1007/s00406-022-01414-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/11/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND Previous studies have suggested that individuals recovered from anorexia nervosa (AN) are characterized by increased serotonergic (5-HT) activity that might be related to elevated levels of anxiety. Assuming these traits to be also present in individuals at risk for AN, it was further hypothesized that restricting food intake might be a means to temporarily alleviate dysphoric affective states by reducing central nervous availability of tryptophan (TRP), the sole precursor of 5-HT. One study that supported this hypothesis found anxiolytic effects in individuals with a history of AN during an experimentally induced short-term depletion of TRP supply to the brain. METHODS In this placebo-controlled, double-blind cross-over study, 22 patients weight-recovered from AN (recAN) and 25 healthy control participants (HC) completed questionnaires assessing anxiety and momentary mood during acute tryptophan depletion (ATD), a dietary intervention that lowers central 5-HT synthesis. RESULTS The ATD procedure effectively reduced the ratio of TRP to competing for large neutral amino acids in the peripheral blood, indicating decreased TRP supply to the brain. Effects of ATD on anxiety and mood did not differ between recAN and HC. Bayesian null hypothesis testing confirmed these initial results. DISCUSSION Our results do not support the hypothesis that short-term depletion of TRP and its impact on the brain 5-HT reduces anxiety or improves mood in AN. As the evidence for the role of 5-HT dysfunction on affective processes in patients with AN is limited, further studies are needed to assess its relevance in the pathophysiology of AN.
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Boehm I, Hennig J, Ritschel F, Geisler D, King JA, Lesch I, Roessner V, Zepf FD, Ehrlich S. Acute tryptophan depletion balances altered resting-state functional connectivity of the salience network in female patients recovered from anorexia nervosa. J Psychiatry Neurosci 2022; 47:E351-E358. [PMID: 36195339 PMCID: PMC9533767 DOI: 10.1503/jpn.210161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/03/2022] [Accepted: 04/17/2022] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND It has been suggested that individuals predisposed to or recovered from anorexia nervosa experience a hyperserotonergic state associated with anxiety that might be mitigated by restricted food intake, because diminished levels of the tryptophan precursor lower the central availability of serotonin (5-HT). At the neural level, the salience network is a system of functionally connected brain regions; it has been closely associated with 5-HT functioning and mental disorders (including anorexia nervosa). The aim of the present study was to investigate the effect on the salience network of a temporary dietary manipulation of 5-HT synthesis in patients with anorexia nervosa. METHODS In this double-blind crossover study, we obtained data on resting-state functional connectivity from 22 weight-recovered female patients with a history of anorexia nervosa, and 22 age-matched female healthy controls. The study procedure included acute tryptophan depletion (a dietary intervention that lowers the central 5-HT synthesis rate) and a sham condition. RESULTS We identified an interaction of group and experimental condition in resting-state functional connectivity between the salience network and the orbitofrontal cortex extending to the frontal pole (F 1,42 = 12.52; p FWE = 0.026). Further analysis revealed increased resting-state functional connectivity during acute tryptophan depletion in patients recovered from anorexia nervosa, resembling that of healthy controls during the sham condition (T 42 = -0.66; p = 0.51). LIMITATIONS The effect of acute tryptophan depletion on the central availability of 5-HT can be judged only indirectly using plasma ratios of tryptophan to large neutral amino acids. Moreover, the definition of anorexia nervosa recovery varies widely across studies, limiting comparability. CONCLUSION Taken together, our findings support the notion of 5-HT dysregulation in anorexia nervosa and indicate that reduced 5-HT synthesis and availability during acute tryptophan depletion (and possibly with food restriction) may balance hyperserotonergic functioning and the associated resting-state functional connectivity of the salience network.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Stefan Ehrlich
- From the Translational Developmental Neuroscience Section, Division of Psychological and Social Medicine and Developmental Neurosciences, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Boehm, Hennig, Ritschel, Geisler, King, Lesch, Ehrlich); the Department of Child and Adolescent Psychiatry, Faculty of Medicine, University Hospital C. G. Carus, Technische Universität Dresden, Dresden, Germany (Roessner); the Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Jena University Hospital, Friedrich Schiller University, Jena, Germany (Zepf); the Eating Disorder Treatment and Research Centre, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Ehrlich)
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Tryptophan modulation in individuals with attention deficit hyperactivity disorder: a systematic review. J Neural Transm (Vienna) 2022; 129:361-377. [PMID: 35286460 PMCID: PMC9007797 DOI: 10.1007/s00702-022-02478-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/11/2022] [Indexed: 12/28/2022]
Abstract
The serotonergic system is implicated in ADHD, but the impact of serotonin’s precursor molecule, tryptophan, on ADHD symptomology remains unclear. Systematic searches of randomised controlled trials with an experimental tryptophan intervention in children and adults with ADHD identified 14 studies measuring core and related symptoms of the condition. Risk of bias was assessed using the Cochrane Risk of Bias tool. The 14 studies all used acute tryptophan depletion procedures, and most did not investigate core ADHD symptoms (inattention, impulsivity, hyperactivity) as primary outcome measures. Only two studies examined attention and revealed mixed effects of tryptophan. Similar effects were found for impulsivity in a small number of studies. No studies investigated hyperactivity. Most studies focused on reactive aggression, but samples were heterogenous and small, rendering potential meta-analyses inconclusive or misleading. However, the narrative analysis indicates tryptophan interventions may impact reactive aggression. More research is needed on the effect of tryptophan modulation on core ADHD symptoms, especially in adults, using more diverse samples to determine potential as an intervention. From current data, tryptophan modulation appears to alter aggressive behaviour in ADHD; however, the available studies were insufficient for the planned meta-analysis.
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Effects of serotonin and dopamine depletion on neural prediction computations during social learning. Neuropsychopharmacology 2020; 45:1431-1437. [PMID: 32330925 PMCID: PMC7360591 DOI: 10.1038/s41386-020-0678-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 04/06/2020] [Accepted: 04/08/2020] [Indexed: 01/23/2023]
Abstract
We have previously shown that individuals with high depression scores demonstrate impaired behavioral and neural responses during social learning. Given that depression is associated with altered dopamine (DA) and serotonin (5-HT) functioning, the current study aimed to elucidate the role of these neurotransmitters in the social learning process using a dietary depletion manipulation. In a double-blind design, 70 healthy volunteers were randomly allocated to a 5-HT depletion (N = 24), DA depletion (N = 24), or placebo (N = 22) group. Participants performed a social learning task during fMRI scanning, as part of which they learned associations between name cues and rewarding (happy faces) or aversive (fearful faces) social outcomes. Behaviorally, 5-HT depleted subjects demonstrated impaired social reward learning compared to placebo controls, with a marginal effect in the same direction in the DA depletion group. On the neural level, computational modeling-based fMRI analyses revealed that 5-HT depletion altered social reward prediction signals in the insula, temporal lobe, and prefrontal cortex, while DA depletion affected social reward prediction encoding only in the prefrontal cortex. These results indicate that 5-HT depletion impairs learning from social rewards, on both the behavioral and the neural level, while DA depletion has a less extensive effect. Interestingly, the behavioral and neural responses observed after 5-HT depletion in the current study closely resemble our previous findings in individuals with high depression scores using the same task. It may thus be the case that decreased 5-HT levels contribute to social learning deficits in depression.
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Stewart RM, Wong JWY, Mahfouda S, Morandini HAE, Rao P, Runions KC, Zepf FD. Acute Tryptophan Depletion Moja-De: A Method to Study Central Nervous Serotonin Function in Children and Adolescents. Front Psychiatry 2020; 10:1007. [PMID: 32210845 PMCID: PMC7067742 DOI: 10.3389/fpsyt.2019.01007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 12/20/2019] [Indexed: 11/13/2022] Open
Abstract
Serotonin (5-HT) is widely implicated as a key neurotransmitter relevant to a range of psychiatric disorders and psychological processes. The role of central nervous 5-HT function underlying these processes can be examined through serotonergic challenge methodologies. Acute tryptophan depletion (ATD) is a key challenge method whereby a diminished dietary intake of tryptophan-the amino acid precursor to brain 5-HT synthesis-results in temporary diminished central nervous 5-HT synthesis. While this particular methodology has been used in adult populations, it was only recently that modifications were made to enable the use of ATD in child and adolescent populations. Additionally, the Moja-De modification of the ATD challenge methodology has demonstrated benefits over other ATD techniques used previously. The aim of this protocol paper is to describe the ATD Moja-De methodology in detail, its benefits, as well as studies that have been conducted to validate the procedure in child and adolescent samples. The ATD Moja-De protocol provides a potential methodology for investigating the role of central nervous 5-HT via manipulation of brain tryptophan availability in human psychopathology from a developmental viewpoint.
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Affiliation(s)
- Richard M. Stewart
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Janice W. Y. Wong
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
- Brain and Behaviour, Telethon Kids Institute, Perth, WA, Australia
- Specialised Child and Adolescent Mental Health Services, Department of Health, Perth, WA, Australia
| | - Simone Mahfouda
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
- Brain and Behaviour, Telethon Kids Institute, Perth, WA, Australia
- School of Psychological Sciences, Faculty of Science, The University of Western Australia, Perth, WA, Australia
| | - Hugo A. E. Morandini
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Pradeep Rao
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
- Community Child and Adolescent Mental Health Services, Department of Health, Perth, WA, Australia
| | - Kevin C. Runions
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
- Brain and Behaviour, Telethon Kids Institute, Perth, WA, Australia
- Community Child and Adolescent Mental Health Services, Department of Health, Perth, WA, Australia
| | - Florian D. Zepf
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
- Brain and Behaviour, Telethon Kids Institute, Perth, WA, Australia
- Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Jena University Hospital, Friedrich Schiller University, Jena, Germany
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Königschulte W, Civai C, Hildebrand P, Gaber TJ, Fink GR, Zepf FD. Effects of serotonin depletion and dopamine depletion on bimodal divided attention. World J Biol Psychiatry 2020; 21:183-194. [PMID: 30295116 DOI: 10.1080/15622975.2018.1532110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Objectives: This study aimed to explore the effects of acute phenylalanine tyrosine depletion (APTD) and acute tryptophan depletion (ATD) on bimodal divided attention. A balanced amino acid mixture (BAL) served as control condition.Methods: Fifty-three healthy adults (final analyzed sample was N = 49, age: M = 23.8 years) were randomly assigned to APTD, ATD or BAL in a double-blind, between-subject approach. Divided attention was assessed after 4 h. Blood samples were taken before and 6 h after challenge intake.Results: Amino acid concentrations following challenge intake significantly decreased (all P ≤ 0.01). There was a significant difference in the mean reaction time (RT) towards auditory stimuli, but not towards visual stimuli between the groups. Post-hoc comparison of mean RTs (auditory stimuli) showed a significant difference between ATD (RT = 604.0 ms, SD = 56.9 ms) and APTD (RT = 556.4 ms, SD = 54.2 ms; P = 0.037), but no RT difference between ATD and BAL or APTD and BAL (RT = 573.6 ms, SD = 45.7 ms).Conclusions: The results indicate a possible dissociation between the effects of a diminished brain 5-HT and DA synthesis on the performance in a bimodal divided attention task. The difference was exclusively observed within the RT towards auditory signals.
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Affiliation(s)
- W Königschulte
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - C Civai
- School of Psychology, University of Kent, Canterbury, UK
| | - P Hildebrand
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - T J Gaber
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - G R Fink
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany.,Department of Neurology, University of Cologne, Cologne, Germany
| | - F D Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Jena University Hospital, Friedrich Schiller University Jena, Germany.,Centre and Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences & Division of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, The University of Western Australia, Perth, Australia.,Telethon Kids Institute, Perth, Australia
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Neukam PT, Deza-Araujo YI, Marxen M, Pooseh S, Rietschel M, Schwarzenbolz U, Smolka MN. No evidence for the involvement of serotonin or the 5-HTTLPR genotype in intertemporal choice in a larger community sample. J Psychopharmacol 2019; 33:1377-1387. [PMID: 31547761 DOI: 10.1177/0269881119874417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Serotonin has been implicated in impulsive behaviours such as temporal discounting. While animal studies and theoretical approaches suggest that reduced tonic serotonin levels increase temporal discounting rates and vice versa, evidence from human studies is scarce and inconclusive. Furthermore, an important modulator of serotonin signalling, a genetic variation in the promoter region of the serotonin transporter gene (5-HTTLPR), has not been investigated for temporal discounting so far. OBJECTIVE First, the purpose of this study was to test for a significant association between 5-HTTLPR and temporal discounting. Second, we wished to investigate the effect of high/low tonic serotonin levels on intertemporal choice and blood oxygen-level-dependent response, controlling for 5-HTTLPR. METHODS We tested the association of 5-HTTLPR with temporal discounting rates using an intertemporal choice task in 611 individuals. We then manipulated tonic serotonin levels with acute tryptophan interventions (depletion, loading, balanced) in a subsample of 45 short (S)-allele and 45 long (L)/L-allele carriers in a randomised double-blind crossover design using functional magnetic resonance imaging and an intertemporal choice task. RESULTS Overall, we did not find any effect of serotonin and 5-HTTLPR on temporal discounting rates or the brain networks associated with valuation and cognitive control. CONCLUSION Our findings indicate that serotonin may not be directly involved in choices including delays on longer timescales such as days, weeks or months. We speculate that serotonin plays a stronger role in dynamic intertemporal choice tasks where the delays are on a timescale of seconds and hence are therefore directly experienced during the experiment.
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Affiliation(s)
- Philipp T Neukam
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Yacila I Deza-Araujo
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Michael Marxen
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Shakoor Pooseh
- Freiburg Center for Data Analysis and Modeling, Freiburg, Germany
| | - Marcella Rietschel
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Uwe Schwarzenbolz
- Institute of Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Michael N Smolka
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
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Hildebrandt CS, Helmbold K, Linden M, Langen KJ, Filss CP, Runions KC, Stewart RM, Rao P, Moore JK, Mahfouda S, Morandini HAE, Wong JWY, Rink L, Zepf FD. No detectable effects of acute tryptophan depletion on short-term immune system cytokine levels in healthy adults. World J Biol Psychiatry 2019; 20:416-423. [PMID: 29353534 DOI: 10.1080/15622975.2018.1428357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Objectives: Recent research suggested an influence of diminished central nervous serotonin (5-HT) synthesis on the leptin axis via immunological mechanisms in healthy adult females. However, studies assessing immunological parameters in combination with dietary challenge techniques that impact brain 5-HT synthesis in humans are lacking. Methods: In the present trial, a pilot analysis was conducted on data obtained in healthy adult humans receiving either different dietary acute tryptophan depletion (ATD) challenge or tryptophan (TRP)-balanced control conditions (BAL) to study the effects of reduced central nervous 5-HT synthesis on serum tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 concentrations. The data of N = 35 healthy adults were analysed who were randomly subjected to one of the following two dietary conditions in a double-blind between-subject approach: (1) The Moja-De ATD challenge (ATD), or (2) TRP-balanced control condition for ATD Moja-De (BAL). Serum concentrations for the assessment of relevant parameters (TNF-α, IL-1β and IL-6) and relevant TRP-related characteristics after the respective challenge procedures were assessed at baseline (T0) and in hourly intervals after administration over a period of 6 h (T1-T6). Results: The ATD condition did not result in significant changes to cytokine concentrations for the entire study sample, or in male and female subgroups. Depletion of CNS 5-HT via dietary TRP depletion appears to have no statistically significant short-term impact on cytokine concentrations in healthy adults. Conclusions: Future research on immunological stressors in combination with challenge techniques will be of value in order to further disentangle the complex interplay between brain 5-HT synthesis and immunological pathways.
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Affiliation(s)
- Caroline S Hildebrandt
- a Jülich Aachen Research Alliance, JARA Translational Brain Medicine , Aachen , Germany.,b Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy , RWTH Aachen University , Aachen , Germany.,c Clinics of the City Cologne GmbH , Child and Adolescent Psychiatry and Psychotherapy , Cologne , Germany
| | - Katrin Helmbold
- a Jülich Aachen Research Alliance, JARA Translational Brain Medicine , Aachen , Germany.,b Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy , RWTH Aachen University , Aachen , Germany
| | - Maike Linden
- a Jülich Aachen Research Alliance, JARA Translational Brain Medicine , Aachen , Germany.,b Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy , RWTH Aachen University , Aachen , Germany
| | - Karl-Josef Langen
- d Institute of Neuroscience and Medicine (INM-4) Research Centre Jülich , Jülich , Germany.,e Section JARA-Brain , Jülich-Aachen Research Alliance (JARA) , Jülich , Germany.,f Department of Nuclear Medicine , RWTH Aachen University Hospital , Aachen , Germany
| | - C P Filss
- e Section JARA-Brain , Jülich-Aachen Research Alliance (JARA) , Jülich , Germany.,f Department of Nuclear Medicine , RWTH Aachen University Hospital , Aachen , Germany
| | - Kevin C Runions
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia.,h Telethon Kids Institute , Perth , Australia
| | - Richard M Stewart
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia
| | - Pradeep Rao
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia.,i Department of Health , Community Child and Adolescent Mental Health Services (CAMHS) , Perth , Western Australia , Australia
| | - Julie K Moore
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia.,j Princess Margaret Hospital, Department of Health , Pediatric Consultation Liason Program, Acute Child and Adolescent Mental Health Services (CAMHS) , Perth , Western Australia , Australia
| | - Simone Mahfouda
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia.,h Telethon Kids Institute , Perth , Australia
| | - Hugo A E Morandini
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia
| | - Janice W Y Wong
- g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia.,h Telethon Kids Institute , Perth , Australia.,k Department of Health , Specialised Child and Adolescent Mental Health Services (CAMHS) , Perth , Western Australia , Australia
| | - Lothar Rink
- l Department of Immunology , RWTH Aachen University Hospital , Aachen , Germany
| | - Florian D Zepf
- a Jülich Aachen Research Alliance, JARA Translational Brain Medicine , Aachen , Germany.,b Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy , RWTH Aachen University , Aachen , Germany.,g Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health , The University of Western Australia , Perth , Australia.,h Telethon Kids Institute , Perth , Australia.,k Department of Health , Specialised Child and Adolescent Mental Health Services (CAMHS) , Perth , Western Australia , Australia
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11
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Microbiota Alterations in Alzheimer’s Disease: Involvement of the Kynurenine Pathway and Inflammation. Neurotox Res 2019; 36:424-436. [DOI: 10.1007/s12640-019-00057-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 12/15/2022]
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12
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Deza-Araujo YI, Neukam PT, Marxen M, Müller DK, Henle T, Smolka MN. Acute tryptophan loading decreases functional connectivity between the default mode network and emotion-related brain regions. Hum Brain Mapp 2018; 40:1844-1855. [PMID: 30585373 DOI: 10.1002/hbm.24494] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 11/26/2018] [Accepted: 11/29/2018] [Indexed: 12/21/2022] Open
Abstract
It has been shown that the functional architecture of the default mode network (DMN) can be affected by serotonergic challenges and these effects may provide insights on the neurobiological bases of depressive symptomatology. To deepen our understanding of this possible interplay, we used a double-blind, randomized, cross-over design, with a control condition and two interventions to decrease (tryptophan depletion) and increase (tryptophan loading) brain serotonin synthesis. Resting-state fMRI from 85 healthy subjects was acquired for all conditions 3 hr after the ingestion of an amino acid mixture containing different amounts of tryptophan, the dietary precursor of serotonin. The DMN was derived for each participant and session. Permutation testing was performed to detect connectivity changes within the DMN as well as between the DMN and other brain regions elicited by the interventions. We found that tryptophan loading increased tryptophan plasma levels and decreased DMN connectivity with visual cortices and several brain regions involved in emotion and affect regulation (i.e., putamen, subcallosal cortex, thalamus, and frontal cortex). Tryptophan depletion significantly reduced tryptophan levels but did not affect brain connectivity. Subjective ratings of mood, anxiety, sleepiness, and impulsive choice were not strongly affected by any intervention. Our data indicate that connectivity between the DMN and emotion-related brain regions might be modulated by changes in the serotonergic system. These results suggest that functional changes in the brain associated with different brain serotonin levels may be relevant to understand the neural bases of depressive symptoms.
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Affiliation(s)
- Yacila I Deza-Araujo
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Philipp T Neukam
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Michael Marxen
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Dirk K Müller
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Thomas Henle
- Institute of Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Michael N Smolka
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
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13
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Stewart RM, Hood SD, Rao P, Moore JK, Runions KC, Murphy SE, Wong JWY, Zepf FD. Using acute tryptophan depletion to investigate predictors of treatment response in adolescents with major depressive disorder: study protocol for a randomised controlled trial. Trials 2018; 19:434. [PMID: 30097056 PMCID: PMC6086023 DOI: 10.1186/s13063-018-2791-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 07/06/2018] [Indexed: 11/21/2022] Open
Abstract
Background Selective serotonin reuptake inhibitors (SSRIs) are amongst the most prescribed antidepressants for adolescents with depressive symptoms and major depressive disorder. However, SSRIs have significant shortcomings as a first-line treatment considering that not all patients respond to these antidepressants. Amongst paediatric populations, meta-analyses indicate that up to approximately 40% of patients do not respond, and for those who do show benefit, there is substantial heterogeneity in response onset. The neurotransmitter serotonin (5-HT) plays a role in the clinical effectiveness and mechanisms of action of SSRIs. However, the exact and complete mechanism of action and reasons for the low response rate to SSRIs in some adolescent populations remains unknown. Methods To examine SSRI response and the role of 5-HT, this study will employ a randomised double-blind within subject, repeated measures design, recruiting adolescent patients with major depressive disorder. Participants will be subjected to acute tryptophan depletion (ATD) and the balanced control condition on two separate study days within a first study phase (Phase A), and the order in which these conditions (ATD/balanced control condition) occur will be random. This phase will be followed by Phase B, where participants will receive open label pharmacological treatment as usual with the SSRI fluoxetine and followed-up over a 12-week period. Discussion ATD is a neurodietary method typically used to investigate the impact of lowered brain 5-HT synthesis on mood and behaviour. The major hypothesis of this study is that ATD will be negatively associated with mood and cognitive functioning, therefore reflecting individual serotonergic sensitivity and related depressive symptoms. Additionally, we expect the aforementioned effects of ATD administration on mood to predict clinical improvement with regard to overall depressive symptomatology 12 weeks into SSRI treatment. Trial registration Australian and New Zealand Clinical Trials Registry (ANZCTR) ACTRN12616001561471. Registered on 11 November 2016. Electronic supplementary material The online version of this article (10.1186/s13063-018-2791-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard M Stewart
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Divisions of Paediatrics and Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway (M561), Crawley WA, Perth, 6009, Australia
| | - Sean D Hood
- Division of Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Australia
| | - Pradeep Rao
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Divisions of Paediatrics and Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway (M561), Crawley WA, Perth, 6009, Australia.,Community Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, Australia
| | - Julia K Moore
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Divisions of Paediatrics and Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway (M561), Crawley WA, Perth, 6009, Australia.,Paediatric Consult-Liaison, Acute Child and Adolescent Mental Health Services (CAMHS), Department of Health, Perth, Western Australia, Australia
| | - Kevin C Runions
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Divisions of Paediatrics and Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway (M561), Crawley WA, Perth, 6009, Australia.,Community Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, Australia.,Telethon Kids Institute, Perth, Australia
| | - Susannah E Murphy
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, UK
| | - Janice W Y Wong
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Divisions of Paediatrics and Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway (M561), Crawley WA, Perth, 6009, Australia.,Telethon Kids Institute, Perth, Australia.,Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, Australia
| | - Florian D Zepf
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Divisions of Paediatrics and Psychiatry, UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway (M561), Crawley WA, Perth, 6009, Australia. .,Telethon Kids Institute, Perth, Australia. .,Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, Australia.
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14
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Neukam PT, Kroemer NB, Deza Araujo YI, Hellrung L, Pooseh S, Rietschel M, Witt SH, Schwarzenbolz U, Henle T, Smolka MN. Risk-seeking for losses is associated with 5-HTTLPR, but not with transient changes in 5-HT levels. Psychopharmacology (Berl) 2018; 235:2151-2165. [PMID: 29730700 DOI: 10.1007/s00213-018-4913-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/17/2018] [Indexed: 10/17/2022]
Abstract
RATIONALE Serotonin (5-HT) plays a key role in different aspects of value-based decision-making. A recent framework proposed that tonic 5-HT (together with dopamine, DA) codes future average reward expectations, providing a baseline against which possible choice outcomes are compared to guide decision-making. OBJECTIVES To test whether high 5-HT levels decrease loss aversion, risk-seeking for gains, and risk-seeking for losses. METHODS In a first session, 611 participants were genotyped for 5-HTTLPR and performed a mixed gambles (MGA) task and two probability discounting tasks for gains and losses, respectively (PDG/PDL). Afterwards, a subsample of 105 participants (44 with S/S, 6 with S/L, 55 with L/L genotype) completed the pharmacological study using a crossover design with tryptophan depletion (ATD), loading (ATL), and balanced (BAL) conditions. The same decision constructs were assessed. RESULTS We found increased risk-seeking for losses in S/S compared to L/L individuals at the first visit (p = 0.002). Neither tryptophan depletion nor loading affected decision-making, nor did we observe an interaction between intervention and 5-HTTLPR genotype. CONCLUSION Our data do not support the idea that transient changes of tonic 5-HT affect value-based decision-making. We provide evidence for an association of 5-HTTLPR with risk-seeking for losses, independent of acute 5-HT levels. This indicates that the association of 5-HTTLPR and risk-seeking for losses is mediated via other mechanisms, possibly by differences in the structural development of neural circuits of the 5-HT system during early life phases.
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Affiliation(s)
- Philipp T Neukam
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Nils B Kroemer
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany.,Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Yacila I Deza Araujo
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Lydia Hellrung
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany.,Department of Economics, University of Zürich, Zürich, Switzerland
| | - Shakoor Pooseh
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Marcella Rietschel
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Stephanie H Witt
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Uwe Schwarzenbolz
- Institute of Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Thomas Henle
- Institute of Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Michael N Smolka
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany.
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15
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Birkl P, Kjaer JB, Szkotnicki W, Forsythe P, Harlander-Matauschek A. Acute tryptophan depletion: the first method validation in an avian species (Gallus gallus domesticus). Poult Sci 2018. [PMID: 28641389 DOI: 10.3382/ps/pex142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Acute tryptophan depletion (ATD) is a valuable non-invasive nutritional tool in human and rodent research to study dysfunctions of the serotonergic system and related behavioral disorders. Serotonergic dysfunction is thought to be involved in the pathology of feather pecking behavior of laying hens, one of the most relevant welfare and production issues in modern intensive egg-production systems. ATD temporarily compromises the influx of tryptophan (TRP) across the blood brain barrier which reduces central availability of TRP, the substrate for serotonin (5-HT) synthesis. However, ATD has never before been developed and evaluated in birds. We hereby report that ATD in laying hens effectively depletes plasma levels of TRP to 50% of the baseline concentration, 4 hours after administration. Furthermore, ATD reduces the ratios of TRP towards aromatic amino acids (AAA) by 60% and the ratio of TRP towards large neutral amino acids (LNAA) by 70%, three hours after administration. Further studies will be needed to determine the effects of peripheral depletion on brain TRP and 5-HT levels in birds. However, our study showed for the first time in an avian species that ATD causes lowering of plasma TRP and the ratio in plasma of TRP towards other AAA or LNAA.
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Affiliation(s)
- Patrick Birkl
- Department of Animal Biosciences, University of Guelph, ON N1G 2W1 Guelph, Canada
| | - Joergen B Kjaer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Animal Welfare and Animal Husbandry, Doernbergstrasse 25 & 27, 29223 Celle, Germany
| | - William Szkotnicki
- Department of Animal Biosciences, University of Guelph, ON N1G 2W1 Guelph, Canada
| | - Paul Forsythe
- Brain-body Institute and Firestone Institute for Respiratory Health, Department of Medicine, McMaster University, 50 Carlton Avenue East, L8N 4A6 Hamilton, Canada
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16
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Wong JWY, Morandini HAE, Dingerkus VLS, Gaber TJ, Runions KC, Rao P, Mahfouda S, Helmbold K, Bubenzer-Busch S, Koenemann R, Stewart RM, Zepf FD. Effects of Dietary Acute Tryptophan Depletion (ATD) on NPY Serum Levels in Healthy Adult Humans Whilst Controlling for Methionine Supply-A Pilot Study. Nutrients 2018; 10:E594. [PMID: 29751614 PMCID: PMC5986474 DOI: 10.3390/nu10050594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 04/28/2018] [Accepted: 05/01/2018] [Indexed: 11/19/2022] Open
Abstract
Central nervous serotonin (5-HT) can influence behaviour and neuropsychiatric disorders. Evidence from animal models suggest that lowered levels of neuropeptide Y (NPY) may have similar effects, although it is currently unknown whether decreased central nervous 5-HT impact NPY concentrations. Given that the production of NPY is dependent on the essential amino acid methionine (MET), it is imperative to account for the presence of MET in such investigations. Hence, this study sought to examine the effects of acute tryptophan depletion (ATD; a dietary procedure that temporarily lowers central nervous 5-HT synthesis) on serum concentrations of NPY, whilst using the potential renal acid load indicator (PRAL) to control for levels of MET. In a double-blind repeated measures design, 24 adult humans randomly received an AA-load lacking in TRP (ATD) on one occasion, and a balanced control mixture with TRP (BAL) on a second occasion, both with a PRAL of nearly 47.3 mEq of MET. Blood samples were obtained at 90, 180, and 240 min after each of the AA challenges. ATD, and therefore, diminished substrate availability for brain 5-HT synthesis did not lead to significant changes in serum NPY concentrations over time, compared to BAL, under an acute acidotic stimulus.
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Affiliation(s)
- Janice W Y Wong
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
- Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health, 6009 Perth, Australia.
- Telethon Kids Institute, 6009 Perth, Australia.
| | - Hugo A E Morandini
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
| | - Vita L S Dingerkus
- Acute Child and Adolescent Mental Health Services (CAMHS), Department of Health, 6009 Perth, Australia.
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University Hospital, 52074 Aachen, Germany.
- Department of Ophthalmology, Triemli Hospital Zürich, CH-8063 Zürich, Switzerland.
| | - Tilman J Gaber
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University Hospital, 52074 Aachen, Germany.
| | - Kevin C Runions
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
- Telethon Kids Institute, 6009 Perth, Australia.
- Community Child and Adolescent Mental Health Services (CAMHS), Department of Health, 6009 Perth, Australia.
| | - Pradeep Rao
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
- Department of Ophthalmology, Triemli Hospital Zürich, CH-8063 Zürich, Switzerland.
| | - Simone Mahfouda
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
- Telethon Kids Institute, 6009 Perth, Australia.
- School of Psychological Sciences, Faculty of Science, The University of Western Australia, 6009 Perth, Australia.
| | - Katrin Helmbold
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University Hospital, 52074 Aachen, Germany.
| | - Sarah Bubenzer-Busch
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University Hospital, 52074 Aachen, Germany.
| | - Rebecca Koenemann
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University Hospital, 52074 Aachen, Germany.
| | - Richard M Stewart
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
| | - Florian D Zepf
- Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Medicine, Division of Psychiatry and Clinical Neurosciences and Division of Paediatrics and Child Health, The University of Western Australia, 6009 Perth, Australia.
- Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health, 6009 Perth, Australia.
- Telethon Kids Institute, 6009 Perth, Australia.
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University Hospital, 52074 Aachen, Germany.
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17
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Ioannou S, Williams AL. Preliminary fMRI findings concerning the influence of 5-HTP on food selection. Brain Behav 2017; 7:e00594. [PMID: 28127513 PMCID: PMC5256178 DOI: 10.1002/brb3.594] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 08/10/2016] [Accepted: 09/10/2016] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE This functional magnetic resonance imaging study was designed to observe how physiological brain states can alter food preferences. A primary goal was to observe food-sensitive regions and moreover examine whether 5-HTP intake would activate areas which have been associated with appetite suppression, anorexia, satiety, and weight loss. METHODS AND PROCEDURE Fourteen healthy male and female participants took part in the study, of which half of them received the supplement 5-HTP and the rest vitamin C (control) on an empty stomach. During the scanning session, they passively observed food (high calories, proteins, carbohydrates) and nonfood movie stimuli. RESULTS Within the 5-HTP group, a comparison of food and nonfood stimuli showed significant responses that included the limbic system, the basal ganglia, and the prefrontal, temporal, and parietal cortices. For the vitamin C group, activity was mainly located in temporal and occipital regions. Compared to the vitamin C group, the 5-HTP group in response to food showed increased activation on the VMPFC, the DLPFC, limbic, and temporal regions. For the 5-HTP group, activity in response to food high in protein content compared to food high in calories and carbohydrates was located in the limbic system and the right caudomedial OFC, whereas for the vitamin C group, activity was mainly located at the inferior parietal lobes, the anterior cingulate gyri, and the left ventrolateral OFC. Greater responses to carbohydrates and high calorie stimuli in the vitamin C group were located at the right temporal gyrus, the occipital gyrus, the right VLPFC, whereas for the 5-HTP group, activity was observed at the left VMPFC, the parahippocampal gyrus bilaterally, the occipital lobe, and middle temporal gyri. DISCUSSION In line with the hypotheses, 5-HTP triggered cortical responses associated with healthy body weight as well as cerebral preferences for protein-rich stimuli. The brain's activity is altered by macronutrients rich or deprived in the body. By reading the organisms physiological states and combining them with memory experiences, it constructs behavioral strategies steering an individual toward or in opposition to a particular food.
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Affiliation(s)
- Stephanos Ioannou
- Department of Physiology College of Medicine Alfaisal University Riyadh Saudi Arabia; Department of Life Sciences & Centre for Cognitive Neuroscience Brunel University London Uxbridge Middlesex UK
| | - Adrian L Williams
- Department of Life Sciences & Centre for Cognitive Neuroscience Brunel University London Uxbridge Middlesex UK
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18
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Linden M, Helmbold K, Kempf J, Sippas S, Filss C, Langen KJ, Eisert A, Zepf FD. Dietary tryptophan depletion in humans using a simplified two amino acid formula - a pilot study. Food Nutr Res 2016; 60:29272. [PMID: 27989269 PMCID: PMC5165058 DOI: 10.3402/fnr.v60.29272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 09/26/2016] [Accepted: 11/03/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Acute tryptophan depletion (ATD) is a well-established dietary method in translational brain research used to briefly lower central nervous serotonin (5-hydroxytryptamine (5-HT)) synthesis. A simplified two amino acid ATD formula (ATDPHE/LEU) was developed while reducing the overall amount of amino acids (AAs), with the objective of administration especially in children and adolescents in future studies. OBJECTIVE This study investigated tryptophan (TRP) influx rates across the blood-brain barrier (BBB) after dietary ATDPHE/LEU administration relative to the ATD Moja-De protocol that has been established for use in children and adolescents. DESIGN Seventy-two healthy adults (50% females) were randomized into four groups and administered ATD Moja-De, its TRP-balanced control condition (BAL), ATDPHE/LEU, or its respective control mixture (BALPHE/LEU) in a counterbalanced, double-blind, between-subjects design. Blood samples were collected at baseline and at hourly intervals for 6 h after AA intake. Questionnaires about mood, taste, and challenge tolerance were completed at fixed time points. RESULTS Both challenge mixtures significantly reduced central nervous TRP influx as calculated by Michaelis-Menten kinetics relative to baseline and the respective control conditions with only mild and comparable side effects. A greater decline in TRP influx over the BBB after ATDPHE/LEU administration when compared with ATD Moja-De was detected without group effects for taste, challenge tolerance, and mood. There was unintended initial short increase in plasma TRP concentrations observed after ATDPHE/LEU intake, and a possible redistribution between free and protein-bound TRP triggered by protein synthesis stimulated by the ingested AAs may account for this finding. Moreover, a decline in TRP influx after BALPHE/LEU administration over a 6-h period was observed, and the large amount of PHE in the BALPHE/LEU mixture may be a possible explanation for this particular phenomenon, which could have led to an unexpected increase in displacement of TRP at the BBB in this control condition. CONCLUSIONS This pilot study provides preliminary evidence for the possibility of lowering TRP influx as calculated by Michaelis-Menten kinetics into the brain by using a simplified ATD protocol in humans. The simplified composition of only two AAs, the lower overall AA amount, and the appropriate tolerance are characteristics of the newly developed ATDPHE/LEU protocol. Future studies focusing on the effects of the ATDPHE/LEU protocol and its respective control condition on CSF 5-HIAA concentrations, as well as neurochemical studies in rodents, are needed to further validate this newly developed AA mixture before definite conclusions about its usability in ATD-related research in humans, its specificity, and additional effects can be made.
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Affiliation(s)
- Maike Linden
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Jülich Aachen Research Alliance, Jülich, Germany
| | - Katrin Helmbold
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Jülich Aachen Research Alliance, Jülich, Germany
| | - Janina Kempf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Jülich Aachen Research Alliance, Jülich, Germany.,Faculty of Arts and Social Sciences, Maastricht University, Maastricht, The Netherlands
| | - Shabnam Sippas
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Jülich Aachen Research Alliance, Jülich, Germany.,Faculty of Arts and Social Sciences, Maastricht University, Maastricht, The Netherlands
| | - Christian Filss
- Section JARA-Brain, Jülich-Aachen Research Alliance (JARA), Jülich, Germany
| | - Karl-Josef Langen
- Section JARA-Brain, Jülich-Aachen Research Alliance (JARA), Jülich, Germany.,Institute of Neuroscience and Medicine (INM-3, -4, -5), Research Centre Jülich, Jülich, Germany.,Department of Nuclear Medicine, RWTH Aachen University Hospital, Aachen, Germany
| | - Albrecht Eisert
- Department of Pharmacy, RWTH Aachen University, Aachen, Germany
| | - Florian Daniel Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Jülich Aachen Research Alliance, Jülich, Germany.,Centre and Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, School of Psychiatry and Clinical Neurosciences & School of Paediatrics and Child Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, Australia.,Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, Australia;
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19
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Eisner P, Klasen M, Wolf D, Zerres K, Eggermann T, Eisert A, Zvyagintsev M, Sarkheil P, Mathiak KA, Zepf F, Mathiak K. Cortico-limbic connectivity in MAOA-L carriers is vulnerable to acute tryptophan depletion. Hum Brain Mapp 2016; 38:1622-1635. [PMID: 27935229 DOI: 10.1002/hbm.23475] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/09/2016] [Accepted: 11/14/2016] [Indexed: 01/12/2023] Open
Abstract
INTRODUCTION A gene-environment interaction between expression genotypes of the monoamine oxidase A (MAOA) and adverse childhood experience increases the risk of antisocial behavior. However, the neural underpinnings of this interaction remain uninvestigated. A cortico-limbic circuit involving the prefrontal cortex (PFC) and the amygdala is central to the suppression of aggressive impulses and is modulated by serotonin (5-HT). MAOA genotypes may modulate the vulnerability of this circuit and increase the risk for emotion regulation deficits after specific life events. Acute tryptophan depletion (ATD) challenges 5-HT regulation and may identify vulnerable neuronal circuits, contributing to the gene-environment interaction. METHODS Functional magnetic resonance imaging measured the resting-state state activity in 64 healthy males in a double-blind, placebo-controlled study. Cortical maps of amygdala correlation identified the impact of ATD and its interaction with low- (MAOA-L) and high-expression variants (MAOA-H) of MAOA on cortico-limbic connectivity. RESULTS Across all Regions of Interest (ROIs) exhibiting an ATD effect on cortico-limbic connectivity, MAOA-L carriers were more susceptible to ATD than MAOA-H carriers. In particular, the MAOA-L group exhibited a larger reduction of amygdala connectivity with the right prefrontal cortex and a larger increase of amygdala connectivity with the insula and dorsal PCC. CONCLUSION MAOA-L carriers were more susceptable to a central 5-HT challenge in cortico-limbic networks. Such vulnerability of the cortical serotonergic system may contribute to the emergence of antisocial behavior after systemic challenges, observed as gene-environment interaction. Hum Brain Mapp 38:1622-1635, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Patrick Eisner
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
| | - Martin Klasen
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
| | - Dhana Wolf
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
| | - Klaus Zerres
- Department of Human Genetics, Medical School, RWTH Aachen University, Aachen, Germany
| | - Thomas Eggermann
- Department of Human Genetics, Medical School, RWTH Aachen University, Aachen, Germany
| | - Albrecht Eisert
- Department of Pharmacy, RWTH Aachen University, Aachen, Germany
| | - Mikhail Zvyagintsev
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
| | - Pegah Sarkheil
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
| | - Krystyna A Mathiak
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
| | - Florian Zepf
- Department of Child and Adolescent Psychiatry, School of Psychiatry and Clinical Neurosciences and School of Pediatrics and Child Health; Faculty of Medicine, Dentistry and Health Sciences; The University of Western Australia (M561), Perth, Australia.,Department of Health in Western Australia, Specialized Child and Adolescent Mental Health Services (CAMHS), Perth, Australia
| | - Klaus Mathiak
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,JARA-Translational Brain Medicine, Aachen, Germany
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20
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Biskup CS, Helmbold K, Baurmann D, Klasen M, Gaber TJ, Bubenzer-Busch S, Königschulte W, Fink GR, Zepf FD. Resting state default mode network connectivity in children and adolescents with ADHD after acute tryptophan depletion. Acta Psychiatr Scand 2016; 134:161-71. [PMID: 27145324 DOI: 10.1111/acps.12573] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/25/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Alterations of the default mode network (DMN) have been described in patients with neuropsychiatric disorders, including attention deficit hyperactivity disorder (ADHD), and the neurotransmitter serotonin (5-HT) is known to modulate DMN activity. This study aimed to explore the role of 5-HT on the DMN and its functional connectivity (FC) in young patients with ADHD. METHODS Young male patients with ADHD (n = 12) and healthy controls (n = 10) (both aged 12-17 years) were subjected to acute tryptophan depletion (ATD) and subsequently diminished brain 5-HT synthesis. Three hours after challenge intake (ATD or a balanced control condition, BAL), resting state fMRI scans were obtained. RESULTS In patients, ATD led to attenuated FC of the right superior premotor cortex (BA 6) with the DMN, comparable to the extent found in controls after BAL administration. ATD lowered FC of the left somatosensory cortex (BA 3) with the DMN, independently of the factor group, but with stronger effects in controls. CONCLUSIONS Data reveal a serotonergic modulation of FC between BA 6 and 3, known to be relevant for motor planning and sensory perception, and the DMN, thereby possibly pointing toward ATD acting beneficially on neural planning of motor activity in patients with ADHD.
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Affiliation(s)
- C S Biskup
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM3), Research Centre Jülich, Jülich, Germany
| | - K Helmbold
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - D Baurmann
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM3), Research Centre Jülich, Jülich, Germany
| | - M Klasen
- Department of Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany
| | - T J Gaber
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - S Bubenzer-Busch
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM3), Research Centre Jülich, Jülich, Germany
| | - W Königschulte
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM3), Research Centre Jülich, Jülich, Germany
| | - G R Fink
- Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM3), Research Centre Jülich, Jülich, Germany.,Department of Neurology, University of Cologne, Cologne, Germany
| | - F D Zepf
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM3), Research Centre Jülich, Jülich, Germany.,Centre & Discipline of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy; School of Psychiatry and Clinical Neurosciences & School of Paediatrics and Child Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, WA, Australia.,Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, WA, Australia
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21
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Serotonergic modulation of resting state default mode network connectivity in healthy women. Amino Acids 2016; 48:1109-1120. [PMID: 26767373 DOI: 10.1007/s00726-015-2137-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 11/16/2015] [Indexed: 09/29/2022]
Abstract
The default mode network (DMN) plays a central role in intrinsic thought processes. Altered DMN connectivity has been linked to diminished cerebral serotonin synthesis. Diminished brain serotonin synthesis is further associated with a lack of impulse control and various psychiatric disorders. Here, we investigated the serotonergic modulation of intrinsic functional connectivity (FC) within the DMN in healthy adult females, controlling for the menstrual cycle phase. Eighteen healthy women in the follicular phase (aged 20-31 years) participated in a double-blind controlled cross-over study of serotonin depletion. Acute tryptophan depletion (ATD) and a balanced amino acid load (BAL), used as the control condition, were applied on two separate days of assessment. Neural resting state data using functional magnetic resonance imaging (fMRI) and individual trait impulsivity scores were obtained. ATD compared with BAL significantly reduced FC with the DMN in the precuneus (associated with self-referential thinking) and enhanced FC with the DMN in the frontal cortex (associated with cognitive reasoning). Connectivity differences with the DMN between BAL and ATD in the precentral gyrus were significantly correlated with the magnitude of serotonin depletion. Right medial frontal gyrus and left superior frontal gyrus connectivity differences with the DMN were inversely correlated with trait impulsivity. These findings partially deviate from previous findings obtained in males and underline the importance of gender-specific studies and controlling for menstrual cycle to further elucidate the mechanism of ATD-induced changes within intrinsic thought processes.
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Maciejak P, Szyndler J, Turzyńska D, Sobolewska A, Kołosowska K, Krząścik P, Płaźnik A. Is the interaction between fatty acids and tryptophan responsible for the efficacy of a ketogenic diet in epilepsy? The new hypothesis of action. Neuroscience 2016; 313:130-48. [DOI: 10.1016/j.neuroscience.2015.11.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 01/09/2023]
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Zepf F, Rao P, Moore J, Stewart R, Ladino YM, Hartmann B. Human breast milk and adipokines – A potential role for the soluble leptin receptor (sOb-R) in the regulation of infant energy intake and development. Med Hypotheses 2016; 86:53-5. [DOI: 10.1016/j.mehy.2015.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/19/2015] [Indexed: 11/29/2022]
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Sánchez CL, Van Swearingen AED, Arrant AE, Biskup CS, Kuhn CM, Zepf FD. Simplified dietary acute tryptophan depletion: effects of a novel amino acid mixture on the neurochemistry of C57BL/6J mice. Food Nutr Res 2015; 59:27424. [PMID: 26278978 PMCID: PMC4538305 DOI: 10.3402/fnr.v59.27424] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 06/24/2015] [Accepted: 06/24/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Diet and nutrition can impact on the biological processes underpinning neuropsychiatric disorders. Amino acid (AA) mixtures lacking a specific neurotransmitter precursor can change the levels of brain serotonin (5-HT) or dopamine (DA) in the central nervous system. The availability of these substances within the brain is determined by the blood-brain barrier (BBB) that restricts the access of peripheral AA into the brain. AA mixtures lacking tryptophan (TRP) compete with endogenous TRP for uptake into the brain across the BBB, which in turn leads to a decrease in central nervous 5-HT synthesis. OBJECTIVE The present study compared the effects of a simplified acute tryptophan depletion (SATD) mixture in mice on blood and brain serotonergic and dopaminergic metabolites to those of a commonly used acute tryptophan depletion mixture (ATD Moja-De) and its TRP-balanced control (BAL). DESIGN The SATD formula is composed of only three large neutral AAs: phenylalanine (PHE), leucine (LEU), and isoleucine (ILE). BAL, ATD Moja-De, or SATD formulas were delivered to adult male C57BL/6J mice by gavage. TRP, monoamines, and their metabolites were quantified in blood and brain regions (hippocampus, frontal cortex, amygdala, caudate putamen, and nucleus accumbens). RESULTS Both ATD Moja-De and SATD significantly decreased levels of serum and brain TRP, as well as brain 5-HIAA and 5-HT compared with BAL. SATD reduced HVA levels in caudate but did not alter total DA levels or DOPAC. SATD decreased TRP and serotonergic metabolites comparably to ATD Moja-De administration. CONCLUSION A simplified and more palatable combination of AAs can manipulate serotonergic function and might be useful to reveal underlying monoamine-related mechanisms contributing to different neuropsychiatric disorders.
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Affiliation(s)
- Cristina L Sánchez
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, RWTH Aachen University, Aachen, Germany.,Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
| | | | - Andrew E Arrant
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
| | - Caroline S Biskup
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, RWTH Aachen University, Aachen, Germany
| | - Cynthia M Kuhn
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
| | - Florian D Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, RWTH Aachen University, Aachen, Germany.,Department of Child and Adolescent Psychiatry, School of Paediatrics and Child Health & School of Psychiatry and Clinical Neurosciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, WA, Australia.,Specialised Child and Adolescent Mental Health Services (CAHMS), Department of Health, Perth, WA, Australia;
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Gaber TJ, Dingerkus VLS, Crockett MJ, Bubenzer-Busch S, Helmbold K, Sánchez CL, Dahmen B, Herpertz-Dahlmann B, Zepf FD. Studying the effects of dietary body weight-adjusted acute tryptophan depletion on punishment-related behavioral inhibition. Food Nutr Res 2015; 59:28443. [PMID: 26268708 PMCID: PMC4534625 DOI: 10.3402/fnr.v59.28443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 12/15/2022] Open
Abstract
Background Alterations in serotonergic (5-HT) neurotransmission are thought to play a decisive role in affective disorders and impulse control. Objective This study aims to reproduce and extend previous findings on the effects of acute tryptophan depletion (ATD) and subsequently diminished central 5-HT synthesis in a reinforced categorization task using a refined body weight–adjusted depletion protocol. Design Twenty-four young healthy adults (12 females, mean age [SD]=25.3 [2.1] years) were subjected to a double-blind within-subject crossover design. Each subject was administered both an ATD challenge and a balanced amino acid load (BAL) in two separate sessions in randomized order. Punishment-related behavioral inhibition was assessed using a forced choice go/no-go task that incorporated a variable payoff schedule. Results Administration of ATD resulted in significant reductions in TRP measured in peripheral blood samples, indicating reductions of TRP influx across the blood–brain barrier and related brain 5-HT synthesis. Overall accuracy and response time performance were improved after ATD administration. The ability to adjust behavioral responses to aversive outcome magnitudes and behavioral adjustments following error contingent punishment remained intact after decreased brain 5-HT synthesis. A previously observed dissociation effect of ATD on punishment-induced inhibition was not observed. Conclusions Our results suggest that neurodietary challenges with ATD Moja–De have no detrimental effects on task performance and punishment-related inhibition in healthy adults.
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Affiliation(s)
- Tilman J Gaber
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - Vita L S Dingerkus
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany
| | - Molly J Crockett
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Sarah Bubenzer-Busch
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - Katrin Helmbold
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - Cristina L Sánchez
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - Brigitte Dahmen
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - Beate Herpertz-Dahlmann
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany
| | - Florian D Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.,JARA Translational Brain Medicine, Aachen & Jülich, Germany.,Institute for Neuroscience and Medicine, Jülich Research Centre, Jülich, Germany.,Department of Child and Adolescent Psychiatry, School of Psychiatry and Clinical Neurosciences & School of Paediatrics and Child Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, Australia.,Specialised Child and Adolescent Mental Health Services (CAMHS), Department of Health in Western Australia, Perth, WA, Australia;
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26
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Helmbold K, Zvyagintsev M, Dahmen B, Bubenzer-Busch S, Gaber TJ, Crockett MJ, Klasen M, Sánchez CL, Eisert A, Konrad K, Habel U, Herpertz-Dahlmann B, Zepf FD. Effects of serotonin depletion on punishment processing in the orbitofrontal and anterior cingulate cortices of healthy women. Eur Neuropsychopharmacol 2015; 25:846-56. [PMID: 25869157 DOI: 10.1016/j.euroneuro.2015.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 01/27/2015] [Accepted: 02/21/2015] [Indexed: 11/30/2022]
Abstract
Diminished synthesis of the neurotransmitter serotonin (5-HT) has been linked to disrupted impulse control in aversive contexts. However, the neural correlates underlying a serotonergic modulation of female impulsivity remain unclear. The present study investigated punishment-induced inhibition in healthy young women. Eighteen healthy female subjects (aged 20-31) participated in a double-blinded, counterbalanced, placebo-controlled, within subjects, repeated measures study. They were assessed on two randomly assigned occasions that were controlled for menstrual cycle phase. In a randomized order, one day, acute tryptophan depletion (ATD) was used to reduce 5-HT synthesis in the brain. On the other day, participants received a tryptophan-balanced amino acid load (BAL) as a control condition. Three hours after administration of ATD/BAL, neural activity was recorded during a modified Go/No-Go task implementing reward or punishment processes using functional magnetic resonance imaging (fMRI). Neural activation during No-Go trials in punishment conditions after BAL versus ATD administration correlated positively with the magnitude of central 5-HT depletion in the ventral and subgenual anterior cingulate cortices (ACC). Furthermore, neural activation in the medial orbitofrontal cortex (mOFC) and the dorsal ACC correlated positively with trait impulsivity. The results indicate reduced neural sensitivity to punishment after short-term depletion of 5-HT in brain areas related to emotion regulation (subgenual ACC) increasing with depletion magnitude and in brain areas related to appraisal and expression of emotions (mOFC and dorsal ACC), increasing with trait impulsivity. This suggests a serotonergic modulation of neural circuits related to emotion regulation, impulsive behavior, and punishment processing in females.
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Affiliation(s)
- K Helmbold
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany; Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany
| | - M Zvyagintsev
- Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany; RWTH Aachen University, Department of Psychiatry, Psychotherapy and Psychosomatics, Germany
| | - B Dahmen
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany
| | - S Bubenzer-Busch
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany; Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany
| | - T J Gaber
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany; Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany
| | - M J Crockett
- Wellcome Trust Centre for Neuroimaging, University College London, United Kingdom
| | - M Klasen
- Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany; RWTH Aachen University, Department of Psychiatry, Psychotherapy and Psychosomatics, Germany
| | - C L Sánchez
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany; Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany
| | - A Eisert
- Department of Pharmacy, RWTH Aachen University, Aachen, Germany
| | - K Konrad
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany; Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany; Institute for Neuroscience and Medicine, Jülich Research Centre, Germany
| | - U Habel
- Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany; RWTH Aachen University, Department of Psychiatry, Psychotherapy and Psychosomatics, Germany
| | - B Herpertz-Dahlmann
- RWTH Aachen University, Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Germany; Jülich Aachen Research Alliance, JARA Translational Brain Medicine, Germany
| | - F D Zepf
- Department of Health in Western Australia, Specialised Child and Adolescent Mental Health Services (CAMHS), Perth, WA, Australia; Department of Child and Adolescent Psychiatry, School of Psychiatry & Clinical Neurosciences and School of Paediatrics & Child Health, The University of Western Australia, Perth, WA, Australia.
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Hildebrand P, Königschulte W, Gaber TJ, Bubenzer-Busch S, Helmbold K, Biskup CS, Langen KJ, Fink GR, Zepf FD. Effects of dietary tryptophan and phenylalanine-tyrosine depletion on phasic alertness in healthy adults - A pilot study. Food Nutr Res 2015; 59:26407. [PMID: 25933613 PMCID: PMC4417080 DOI: 10.3402/fnr.v59.26407] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 03/22/2015] [Accepted: 03/24/2015] [Indexed: 11/14/2022] Open
Abstract
Background The synthesis of the neurotransmitters serotonin (5-HT) and dopamine (DA) in the brain can be directly altered by dietary manipulation of their relevant precursor amino acids (AA). There is evidence that altered serotonergic and dopaminergic neurotransmission are both associated with impaired attentional control. Specifically, phasic alertness is one specific aspect of attention that has been linked to changes in 5-HT and DA availability in different neurocircuitries related to attentional processes. The present study investigated the impact of short-term reductions in central nervous system 5-HT and DA synthesis, which was achieved by dietary depletion of the relevant precursor AA, on phasic alertness in healthy adult volunteers; body weight–adapted dietary tryptophan and phenylalanine–tyrosine depletion (PTD) techniques were used. Methods The study employed a double-blind between-subject design. Fifty healthy male and female subjects were allocated to three groups in a randomized and counterbalanced manner and received three different dietary challenge conditions: acute tryptophan depletion (ATD, for the depletion of 5-HT; N=16), PTD (for the depletion of DA; N=17), and a balanced AA load (BAL; N=17), which served as a control condition. Three hours after challenge intake (ATD/PTD/BAL), phasic alertness was assessed using a standardized test battery for attentional performance (TAP). Blood samples for AA level analyses were obtained at baseline and 360 min after the challenge intake. Results Overall, there were no significant differences in phasic alertness for the different challenge conditions. Regarding PTD administration, a positive correlation between the reaction times and the DA-related depletion magnitude was detected via the lower plasma tyrosine levels and the slow reaction times of the first run of the task. In contrast, higher tryptophan concentrations were associated with slower reaction times in the fourth run of the task in the same challenge group. Conclusion The present study is the first to demonstrate preliminary data that support an association between decreased central nervous system DA synthesis, which was achieved by dietary depletion strategies, and slower reaction times in specific runs of a task designed to assess phasic alertness in healthy adult volunteers; these findings are consistent with previous evidence that links phasic alertness with dopaminergic neurotransmission. A lack of significant differences between the three groups could be due to compensatory mechanisms and the limited sample size, as well as the dietary challenge procedures administered to healthy participants and the strict exclusion criteria used. The potential underlying neurochemical processes related to phasic alertness should be the subject of further investigations.
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Affiliation(s)
- Patricia Hildebrand
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Werner Königschulte
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Tilman Jakob Gaber
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Sarah Bubenzer-Busch
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Katrin Helmbold
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Caroline Sarah Biskup
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Karl-Josef Langen
- Institute of Neuroscience and Medicine (INM-3, -4, -5), Research Centre Jülich, Jülich, Germany.,Department of Nuclear Medicine, RWTH Aachen University Hospital, Aachen, Germany
| | | | - Florian Daniel Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, JARA Brain, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Department of Child and Adolescent Psychiatry, School of Psychiatry and Clinical Neurosciences & School of Paediatrics and Child Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, Australia.,Specialised Child and Adolescent Mental Health Services (CAHMS), Department of Health in Western Australia, Perth, WA, Australia;
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Biskup CS, Gaber T, Helmbold K, Bubenzer-Busch S, Zepf FD. Amino acid challenge and depletion techniques in human functional neuroimaging studies: an overview. Amino Acids 2015; 47:651-83. [DOI: 10.1007/s00726-015-1919-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 01/09/2015] [Indexed: 01/16/2023]
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Effects of a short-term reduction in brain serotonin synthesis on the availability of the soluble leptin receptor in healthy women. J Neural Transm (Vienna) 2014; 122:343-8. [PMID: 25204277 DOI: 10.1007/s00702-014-1292-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/06/2014] [Indexed: 10/24/2022]
Abstract
Serotonin (5-HT) and the hormone leptin have been linked to the underlying neurobiology of appetite regulation with evidence coming from animal and cellular research, but direct evidence linking these two pathways in humans is lacking. We examined the effects of reduced brain 5-HT synthesis due to acute tryptophan depletion (ATD) on levels of soluble leptin receptor (sOb-R), the main high-affinity leptin binding protein, in healthy adults using an exploratory approach. Women, but not men, showed reduced sOb-R concentrations after ATD administration. With females showing reduced baseline levels of central 5-HT synthesis compared to males diminished brain 5-HT synthesis affected the leptin axis through the sOb-R in females, thereby potentially influencing their vulnerability to dysfunctional appetite regulation and co-morbid mood symptoms.
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Zepf FD, Sánchez CL, Biskup CS, Kötting WF, Bubenzer S, Helmbold K, Eisert A, Gaber TJ, Landgraf M, Dahmen B, Poustka F, Wöckel L, Stadler C, Grabemann M, Mette C, Heinrich V, Uekermann J, Abdel-Hamid M, Kis B, Zimmermann M, Wiltfang J, Kuhn CM. Acute tryptophan depletion - converging evidence for decreasing central nervous serotonin synthesis in rodents and humans. Acta Psychiatr Scand 2014; 129:157-9. [PMID: 24237607 DOI: 10.1111/acps.12215] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- F D Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany; JARA Translational Brain Medicine, Aachen, Jülich, Germany; Institute for Neuroscience and Medicine, Jülich Research Centre, Jülich, Germany.
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31
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von Polier GG, Zepf FD. Physiosomatic complaints, immune-inflammatory pathways, and serotonin-related mood symptoms: relevance for tryptophan-related challenge procedures and clinical considerations with respect to the DSM-V. Acta Psychiatr Scand 2014; 129:98-9. [PMID: 24117193 DOI: 10.1111/acps.12197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- G G von Polier
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany
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32
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von Polier GG, Biskup CS, Kötting WF, Bubenzer S, Helmbold K, Eisert A, Gaber TJ, Zepf FD. Change in electrodermal activity after acute tryptophan depletion associated with aggression in young people with attention deficit hyperactivity disorder (ADHD). J Neural Transm (Vienna) 2013; 121:451-5. [DOI: 10.1007/s00702-013-1119-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 11/08/2013] [Indexed: 10/26/2022]
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33
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Acute tryptophan depletion reduces nitric oxide synthase in the rat hippocampus. Neurochem Res 2013; 38:2595-603. [PMID: 24170240 DOI: 10.1007/s11064-013-1177-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 10/02/2013] [Accepted: 10/05/2013] [Indexed: 10/26/2022]
Abstract
Acute tryptophan depletion (ATD) is extensively used to investigate the role of central serotonin (5-HT). However, several studies reported that ATD had no significant effect on central 5-HT concentration and some ATD-induced changes was independent of 5-HT in the rodent brain. Therefore, the potential mechanism of ATD might not be ascribed solely to changes in the central 5-HT system. In recent studies, evidence suggests that nitric oxide synthase (NOS) is closely associated with ATD-induced changes in modulation of cerebral blood flow and metabolism, cognitive, and locomotor activity. Thus, NOS is implicated to be an underlying factor contributing to ATD-induced changes. In the present study, the effect of ATD upon central NOS levels in the rat was evaluated. Male Sprague-Dawley (SD) rats were orally administered a tryptophan-free protein-carbohydrate mixture. Then, ATD effects upon affective behavior and spatial memory were assessed by the forced swimming test (FST) and Morris water maze test, respectively. Further, NOS activity and neuronal NOS (nNOS) protein levels in the hippocampus were measured after ATD. Our experimental results showed that ATD had no influence on affective behavior in the FST or spatial memory in SD rats. Interestingly, a significant reduction of both constitutive NOS activity and nNOS protein levels after ATD was found in the hippocampus. These findings demonstrate ATD does not influence affective behavior and spatial memory despite a direct effect on hippocampal NOS. Our study might provide a valuable clue for exploring earlier reported ATD-induced behavioral and neurochemical changes in rodents.
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34
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Influence of acute tryptophan depletion on verbal declarative episodic memory in young adult females. Amino Acids 2013; 45:1207-19. [DOI: 10.1007/s00726-013-1582-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 08/15/2013] [Indexed: 10/26/2022]
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Dietary manipulation of serotonergic and dopaminergic function in C57BL/6J mice with amino acid depletion mixtures. J Neural Transm (Vienna) 2013; 121:153-62. [PMID: 24061481 DOI: 10.1007/s00702-013-1083-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/14/2013] [Indexed: 01/24/2023]
Abstract
Amino acid (AA) depletion techniques have been used to decrease serotonin (5-HT) and/or dopamine (DA) synthesis after administration of a tryptophan (acute tryptophan depletion, ATD) or phenylalanine/tyrosine-free (phenylalanine-tyrosine depletion, PTD) AA formula and are useful as neurochemical challenge procedures to study the impact of DA and 5-HT in patients with neuropsychiatric disorders. We recently demonstrated that the refined Moja-De ATD paradigm decreases brain 5-HT synthesis in humans and mice and lowers brain 5-HT turnover. In the present study we validated the neurochemical effects of three developed AA formulas on brain 5-HT and DA function in mice. To distinguish the direct and indirect effects of such mixtures on 5-HT and DA and to determine whether additive depletion of both could be obtained simultaneously, we compared the effects of ATD for 5-HT, PTD for DA, and a combined monoamine depletion mixture (CMD) compared to a control condition consisting of a balanced amino acid mixture. Food-deprived male C57BL/6J mice were gavaged with AA mixtures. Serum and brain samples were collected and analyzed for determination of tryptophan (Trp), tyrosine (Tyr), 5-HT, 5-HIAA, DA, DOPAC and HVA levels. ATD was the most effective at decreasing Trp, 5-HT and 5-HIAA. In contrast, PTD reduced Tyr globally but HVA only in certain brain regions. Although CMD affected both 5-HT and DA synthesis, it was less effective when compared with ATD or PTD alone. The present results demonstrate that two newly developed PTD and CMD formulas differentially impact brain 5-HT and DA synthesis relative to 5-HT-specific ATD Moja-De. Different effects on 5-HT and DA function by these mixtures suggest that the exact composition may be a critical determinant for effectiveness with respect to the administered challenge procedure.
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36
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Young SN. Acute tryptophan depletion in humans: a review of theoretical, practical and ethical aspects. J Psychiatry Neurosci 2013; 38:294-305. [PMID: 23428157 PMCID: PMC3756112 DOI: 10.1503/jpn.120209] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The acute tryptophan depletion (ATD) technique has been used extensively to study the effect of low serotonin in the human brain. This review assesses the validity of a number of published criticisms of the technique and a number of previously unpublished potential criticisms. The conclusion is that ATD can provide useful information when results are assessed in conjunction with results obtained using other techniques. The best-established conclusion is that low serotonin function after tryptophan depletion lowers mood in some people. However, this does not mean that other variables, altered after tryptophan depletion, are necessarily related to low serotonin. Each aspect of brain function has to be assessed separately. Furthermore, a negative tryptophan depletion study does not mean that low serotonin cannot influence the variable studied. This review suggests gaps in knowledge that need to be filled and guidelines for carrying out ATD studies.
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Affiliation(s)
- Simon N. Young
- Correspondence to: S.N. Young, Department of Psychiatry, McGill University, 1033 Pine Ave. W, Montréal QC H3A 1A1;
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Kötting WF, Bubenzer S, Helmbold K, Eisert A, Gaber TJ, Zepf FD. Effects of tryptophan depletion on reactive aggression and aggressive decision-making in young people with ADHD. Acta Psychiatr Scand 2013; 128:114-23. [PMID: 22913430 DOI: 10.1111/acps.12001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE The neurotransmitter serotonin (5-HT) has been linked to the underlying biological processes related to aggressive behaviour. However, only a few studies on this subject involving young people have been published so far. METHOD We aimed to investigate the effects of acute tryptophan depletion (ATD) on reactive aggression and decision-time for aggressive responses in a sample of young people with Attention deficit hyperactivity disorder (n = 20), a population at risk for aggressive behaviour. The study design was a double-blind within-subject crossover design. Aggression was assessed using a Point subtraction aggression game (PSAG) with high (HP) and low provocation (LP) trials 2.5 h after the intake of ATD and a tryptophan-balanced control condition. RESULTS A chi-square comparison was used to identify the effect of ATD on increased aggression after LP. Boys were more likely to respond with an increased aggressive response after HP under ATD as represented by an increased relative risk and odds ratios. Girls had a higher relative risk than boys of an increased point subtraction under ATD after LP. No significant gender differences in decision-time were detected. CONCLUSION An effect of ATD on increased aggression was found in the whole sample after LP. Research involving larger samples is needed to confirm the present preliminary findings.
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Affiliation(s)
- W F Kötting
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany
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38
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Zepf FD. Acute tryptophan depletion--a translational research method for studying the impact of central nervous system serotonin function. Acta Psychiatr Scand 2013; 128:105-6. [PMID: 23829231 DOI: 10.1111/acps.12162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
| | - Florian Daniel Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, and RWTH Aachen University; Aachen; Germany
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Zepf FD, Landgraf M, Biskup CS, Dahmen B, Poustka F, Wöckel L, Stadler C. No effect of acute tryptophan depletion on verbal declarative memory in young persons with ADHD. Acta Psychiatr Scand 2013; 128:133-41. [PMID: 23418985 DOI: 10.1111/acps.12089] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/03/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Animal experiments and studies in adults have shown that the neurotransmitter serotonin (5-HT) plays an important role in learning and memory processes. However, data on this relationship in young persons are scarce, and neurodietary research in this age group is limited compared with the extensive literature on adults. Here, we aimed to explore the effects of a diminished central nervous 5-HT synthesis, which is achieved by acute tryptophan depletion (ATD) Moja-De , on memory function in young males with attention deficit hyperactivity disorder (ADHD). METHOD Twenty-two male patients with ADHD (ages 9-15 years, mean 10.95 ± 1.17 years) received ATD, thus diminishing central nervous 5-HT synthesis, and a tryptophan-balanced amino acid load (BAL) in a randomized, double-blind, within-subject, crossover design study. Approximately 1.7 h after administration of ATD/BAL, verbal declarative memory was assessed using the 'Auditory Verbal-Learning-Test' (AVLT). RESULTS There were no significant effects of ATD administration on verbal declarative memory function. CONCLUSION In this study, changes in 5-HT neurotransmission were not associated with specific aspects of verbal declarative memory in young persons with ADHD. Future studies with healthy control groups that address effects of covarying attentional processes are warranted.
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Affiliation(s)
- F D Zepf
- Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.
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40
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Grabemann M, Mette C, Zimmermann M, Heinrich V, Uekermann J, Wiltfang J, Abdel-Hamid M, Zepf FD, Kis B. No clear effects of acute tryptophan depletion on processing affective prosody in male adults with ADHD. Acta Psychiatr Scand 2013; 128:142-8. [PMID: 23581825 DOI: 10.1111/acps.12130] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/26/2013] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Adults with attention deficit hyperactivity disorder (ADHD) have difficulties processing affective prosody, and research evidence demonstrates the importance of brain serotonin (5-HT) in the neurobiology of ADHD. This study aimed to investigate whether diminished brain 5-HT synthesis, as achieved by acute tryptophan depletion (ATD), can impair the processing of affective prosody in adults with ADHD. METHOD Twenty male patients with ADHD and twenty male healthy controls received ATD and a tryptophan-balanced control condition on separate days in a double-blind within-subject repeated measures crossover design. In both conditions, the Tübingen Affect Battery was administered in which subjects had to name the affective prosody of sentences with neutral, congruent, or incongruent semantic content. RESULTS Participants in the group of patients with ADHD perceived affective prosody less accurately than controls. Participants with ADHD showed compromised processing of sentences, committing more errors than healthy controls when identifying affect in instances of incongruent semantic content (P = 0.031). ATD did not contribute to this effect (all P > 0.5). CONCLUSION The difficulties male adults with ADHD have in accurately processing affective prosody may result from impairments in their ability to inhibit unwanted stimuli and impulses. No clear evidence implicates 5-HT as a cause of these impairments.
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Affiliation(s)
- M Grabemann
- Department of Psychiatry and Psychotherapy, University of Duisburg-Essen, LVR Clinics Essen, Essen, Germany.
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Mette C, Zimmermann M, Grabemann M, Abdel-Hamid M, Uekermann J, Biskup CS, Wiltfang J, Zepf FD, Kis B. The impact of acute tryptophan depletion on attentional performance in adult patients with ADHD. Acta Psychiatr Scand 2013; 128:124-32. [PMID: 23419004 DOI: 10.1111/acps.12090] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/03/2013] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To date, the impact of the neurotransmitter serotonin (5-HT) on different neuropsychological functions in adults with attention deficit hyperactivity disorder (ADHD) is underinvestigated. We aimed to examine the effects of acute tryptophan depletion (ATD) and the resulting reduction in central nervous 5-HT synthesis on target/non-target discrimination ability and sustained attention in adults with ADHD using an AX-Continuous Performance Test (AX-CPT). METHOD Twenty male patients with ADHD (age: M = 30.25 SD = 9.37) and twenty male healthy controls (age: M = 27.90 SD = 6.01) received ATD on one day and a tryptophan-balanced control condition (BAL) on another day in a double-blind within-subject crossover design. A continuous performance test (AX-CPT) with three conditions (AX, AY, and BX) was administered on both days under depleted and sham-depleted conditions. RESULTS In patients omissions increased after ATD when compared with BAL. Patient's reaction time decreased after ATD when compared with BAL, which was contrasted by opposite effects in controls. Patients showed fewer correct responses (AX condition) and showed a higher rate of errors (condition AXE ) independent of ATD or BAL intake. CONCLUSION The present preliminary results are indicative of the contribution of serotonergic neurotransmission to attentional processes in adults with ADHD.
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Affiliation(s)
- C Mette
- Department of Psychiatry and Psychotherapy, LVR Clinics Essen, University of Duisburg-Essen, Essen, Germany.
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Schäuble S, Stavrum AK, Puntervoll P, Schuster S, Heiland I. Effect of substrate competition in kinetic models of metabolic networks. FEBS Lett 2013; 587:2818-24. [PMID: 23811082 DOI: 10.1016/j.febslet.2013.06.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 06/18/2013] [Accepted: 06/18/2013] [Indexed: 11/24/2022]
Abstract
Substrate competition can be found in many types of biological processes, ranging from gene expression to signal transduction and metabolic pathways. Although several experimental and in silico studies have shown the impact of substrate competition on these processes, it is still often neglected, especially in modelling approaches. Using toy models that exemplify different metabolic pathway scenarios, we show that substrate competition can influence the dynamics and the steady state concentrations of a metabolic pathway. We have additionally derived rate laws for substrate competition in reversible reactions and summarise existing rate laws for substrate competition in irreversible reactions.
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Affiliation(s)
- Sascha Schäuble
- Theoretical Systems Biology Group, Friedrich-Schiller-University Jena, Germany
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Biskup CS, Sánchez CL, Arrant A, Van Swearingen AED, Kuhn C, Zepf FD. Effects of acute tryptophan depletion on brain serotonin function and concentrations of dopamine and norepinephrine in C57BL/6J and BALB/cJ mice. PLoS One 2012; 7:e35916. [PMID: 22629305 PMCID: PMC3357407 DOI: 10.1371/journal.pone.0035916] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Accepted: 03/26/2012] [Indexed: 11/30/2022] Open
Abstract
Acute tryptophan depletion (ATD) is a method of lowering brain serotonin (5-HT). Administration of large neutral amino acids (LNAA) limits the transport of endogenous tryptophan (TRP) across the blood brain barrier by competition with other LNAAs and subsequently decreases serotonergic neurotransmission. A recent discussion on the specificity and efficacy of the ATD paradigm for inhibition of central nervous 5-HT has arisen. Moreover, side effects such as vomiting and nausea after intake of amino acids (AA) still limit its use. ATD Moja-De is a revised mixture of AAs which is less nauseating than conventional protocols. It has been used in preliminary clinical studies but its effects on central 5-HT mechanisms and other neurotransmitter systems have not been validated in an animal model. We tested ATD Moja-De (TRP−) in two strains of mice: C57BL/6J, and BALB/cJ, which are reported to have impaired 5-HT synthesis and a more anxious phenotype relative to other strains of mice. ATD Moja-De lowered brain TRP, significantly decreased 5-HT synthesis as indexed by 5-HTP levels after decarboxlyase inhibition, and lowered 5-HT and 5-HIAA in both strains of mice, however more so in C57BL/6J than in BALB/cJ. Dopamine and its metabolites as well as norepinephrine were not affected. A balanced (TRP+) control mixture did not raise 5-HT or 5-HIAA. The present findings suggest that ATD Moja-De effectively and specifically suppresses central serotonergic function. These results also demonstrate a strain- specific effect of ATD Moja-De on anxiety-like behavior.
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Affiliation(s)
- Caroline Sarah Biskup
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
- Institute for Neuroscience and Medicine, Jülich Research Centre, Jülich, Nordrhein-Westfalen, Germany
- JARA Translational Brain Medicine, Aachen & Jülich, Nordrhein-Westfalen, Germany
| | - Cristina L. Sánchez
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
- Institute for Neuroscience and Medicine, Jülich Research Centre, Jülich, Nordrhein-Westfalen, Germany
- JARA Translational Brain Medicine, Aachen & Jülich, Nordrhein-Westfalen, Germany
| | - Andrew Arrant
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Amanda E. D. Van Swearingen
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Cynthia Kuhn
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Florian Daniel Zepf
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
- Institute for Neuroscience and Medicine, Jülich Research Centre, Jülich, Nordrhein-Westfalen, Germany
- JARA Translational Brain Medicine, Aachen & Jülich, Nordrhein-Westfalen, Germany
- * E-mail:
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