TY - JOUR A1 - Sebold, Miriam Hannah A1 - Deserno, Lorenz A1 - Nebe, Stefan A1 - Schad, Daniel A1 - Garbusow, Maria A1 - Haegele, Claudia A1 - Keller, Juergen A1 - Juenger, Elisabeth A1 - Kathmann, Norbert A1 - Smolka, Michael N. A1 - Rapp, Michael Armin A1 - Schlagenhauf, Florian A1 - Heinz, Andreas A1 - Huys, Quentin J. M. T1 - Model-based and model-free decisions in alcohol dependence JF - Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography N2 - Background: Human and animal work suggests a shift from goal-directed to habitual decision-making in addiction. However, the evidence for this in human alcohol dependence is as yet inconclusive. Methods: Twenty-six healthy controls and 26 recently detoxified alcohol-dependent patients underwent behavioral testing with a 2-step task designed to disentangle goal-directed and habitual response patterns. Results: Alcohol-dependent patients showed less evidence of goal-directed choices than healthy controls, particularly after losses. There was no difference in the strength of the habitual component. The group differences did not survive controlling for performance on the Digit Symbol Substitution Task. Conclusion: Chronic alcohol use appears to selectively impair goal-directed function, rather than promoting habitual responding. It appears to do so particularly after nonrewards, and this may be mediated by the effects of alcohol on more general cognitive functions subserved by the prefrontal cortex. KW - Alcohol dependence KW - Decision-making KW - Reinforcement learning KW - Dopamine KW - Computational psychiatry Y1 - 2014 U6 - https://doi.org/10.1159/000362840 SN - 0302-282X SN - 1423-0224 VL - 70 IS - 2 SP - 122 EP - 131 PB - Karger CY - Basel ER - TY - JOUR A1 - Schumacher, Fabian A1 - Chakraborty, Sudipta A1 - Kleuser, Burkhard A1 - Gulbins, Erich A1 - Schwerdtle, Tanja A1 - Aschner, Michael A. A1 - Bornhorst, Julia T1 - Highly sensitive isotope-dilution liquid-chromatography-electrospray ionization-tandem-mass spectrometry approach to study the drug-mediated modulation of dopamine and serotonin levels in Caenorhabditis elegans JF - Talanta : the international journal of pure and applied analytical chemistry N2 - Dopamine (DA) and serotonin (SRT) are monoamine neurotransmitters that play a key role in regulating the central and peripheral nervous system. Their impaired metabolism has been implicated in several neurological disorders, such as Parkinson's disease and depression. Consequently, it is imperative to monitor changes in levels of these low-abundant neurotransmitters and their role in mediating disease. For the first time, a rapid, specific and sensitive isotope-dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of DA and SRT in the nematode Caenorhabditis elegans (C. elegans). This model organism offers a unique approach for studying the effect of various drugs and environmental conditions on neurotransmitter levels, given by the conserved DA and SRT biology, including synaptic release, trafficking and formation. We introduce a novel sample preparation protocol incorporating the usage of sodium thiosulfate in perchloric acid as extraction medium that assures high recovery of the relatively unstable neurotransmitters monitored. Moreover, the use of both deuterated internal standards and the multiple reaction monitoring (MRM) technique allows for unequivocal quantification. Thereby, to the best of our knowledge, we achieve a detection sensitivity that clearly exceeds those of published DA and SRT quantification methods in various matrices. We are the first to show that exposure of C elegans to the monoamine oxidase B (MAOB) inhibitor selegiline or the catechol-O-methyltransferase (COMT) inhibitor tolcapone, in order to block DA and SRT degradation, resulted in accumulation of the respective neurotransmitter. Assessment of a behavioral output of the dopaminergic system (basal slowing response) corroborated the analytical LC-MS/MS data. Thus, utilization of the C elegans model system in conjunction with our analytical method is well-suited to investigate drug-mediated modulation of the DA and SRT system in order to identify compounds with neuroprotective or regenerative properties. (C) 2015 Elsevier B.V. All rights reserved. KW - Caenorhabditis elegans KW - Dopamine KW - Serotonin KW - Liquid chromatography-tandem mass spectrometry KW - Isotope-dilution analysis Y1 - 2015 U6 - https://doi.org/10.1016/j.talanta.2015.05.057 SN - 0039-9140 SN - 1873-3573 VL - 144 SP - 71 EP - 79 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Kaminski, Jakob A1 - Schlagenhauf, Florian A1 - Rapp, Michael Armin A1 - Awasthi, Swapnil A1 - Ruggeri, Barbara A1 - Deserno, Lorenz A1 - Laura, Daedelow A1 - Banaschewski, Tobias A1 - Bokde, Arun A1 - Quinlan, Erin Burke A1 - Buechel, Christian A1 - Bromberg, Uli A1 - Desrivieres, Sylvane A1 - Flor, Herta A1 - Frouin, Vincent A1 - Garavan, Hugh A1 - Gowland, Penny A1 - Ittermann, Bernd A1 - Martinot, Jean-Luc A1 - Martinot, Marie-Laure Paillere A1 - Nees, Frauke A1 - Orfanos, Dimitri Papadopoulos A1 - Paus, Tomas A1 - Poustka, Luise A1 - Smolka, Michael A1 - Froehner, Juliane A1 - Walter, Henrik A1 - Whelan, Robert A1 - Ripke, Stephan A1 - Schumann, Gunter A1 - Heinz, Andreas T1 - Variance in Dopaminergic Markers BT - a possible marker of individual differences in IQ? T2 - Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry KW - Intelligence KW - Dopamine KW - Epigenetic Biomarkers KW - Reward Anticipation KW - Polygenic Risk Score Y1 - 2018 U6 - https://doi.org/10.1016/j.biopsych.2018.02.311 SN - 0006-3223 SN - 1873-2402 VL - 83 IS - 9 SP - S118 EP - S118 PB - Elsevier CY - New York ER - TY - JOUR A1 - Peres, Tanara V. A1 - Horning, Kyle J. A1 - Bornhorst, Julia A1 - Schwerdtle, Tanja A1 - Bowman, Aaron B. A1 - Aschner, Michael T1 - Small Molecule Modifiers of In Vitro Manganese Transport Alter Toxicity In Vivo JF - Biological Trace Element Research N2 - Manganese (Mn) is essential for several species and daily requirements are commonly met by an adequate diet. Mn overload may cause motor and psychiatric disturbances and may arise from an impaired or not fully developed excretion system, transporter malfunction and/or exposure to excessive levels of Mn. Therefore, deciphering processes regulating neuronal Mn homeostasis is essential to understand the mechanisms of Mn neurotoxicity. In the present study, we selected two small molecules (with opposing effects on Mn transport) from a previous high throughput screen of 40,167 to test their effects on Mn toxicity parameters in vivo using Caenorhabditis elegans. We pre-exposed worms to VU0063088 and VU0026921 for 30min followed by co-exposure for 1h with Mn and evaluated Mn accumulation, dopaminergic (DAergic) degeneration and worm survival. Control worms were exposed to vehicle (DMSO) and saline only. In pdat-1::GFP worms, with GFP labeled DAergic neurons, we observed a decrease of Mn-induced DAergic degeneration in the presence of both small molecules. This effect was also observed in an smf-2 knockout strain. SMF-2 is a regulator of Mn transport in the worms and this strain accumulates higher Mn levels. We did not observe improved survival in the presence of small molecules. Our results suggest that both VU0063088 and VU0026921 may modulate Mn levels in the worms through a mechanism that does not require SMF-2 and induce protection against Mn neurotoxicity. KW - Small molecules KW - Manganese KW - Neurotoxicity KW - C. elegans KW - Dopamine Y1 - 2018 U6 - https://doi.org/10.1007/s12011-018-1531-7 SN - 0163-4984 SN - 1559-0720 VL - 188 IS - 1 SP - 127 EP - 134 PB - Human press inc. CY - Totowa ER -