The Experts below are selected from a list of 57786 Experts worldwide ranked by ideXlab platform
Christian J. Fiebach - One of the best experts on this subject based on the ideXlab platform.
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effects of dopamine related gene gene interactions on working Memory Component processes
European Journal of Neuroscience, 2009Co-Authors: Christine Stelzel, Ulrike Basten, Christian Montag, Martin Reuter, Christian J. FiebachAbstract:Dopamine modulates complex cognitive functions like working Memory and cognitive control. It is widely accepted that an optimal level of prefrontal dopamine supports working Memory performance. In the present study we used a molecular genetic approach to test whether the optimal activity of the dopamine system for different Component processes of working Memory is additionally related to the availability of dopamine D2 receptors. We sought evidence for this assumption by investigating the interaction effect (epistasis) of variations in two dopaminergic candidate genes: the catechol-O-methyltransferase (COMT) Val(158)Met polymorphism, which has been shown to influence prefrontal dopamine concentration, and the DRD2/ANKK1-Taq-Ia polymorphism, which has been related to the density of D2 receptors. Our results show that COMT effects on working Memory performance are modulated by the DRD2/ANKK1-TAQ-Ia polymorphism and the specific working Memory Component process under investigation. Val- participants - supposedly characterized by increased prefrontal dopamine concentrations - outperformed Val+ participants in the manipulation of working Memory contents, but only when D2 receptor density could be considered to be high. No such effect was present for passive maintenance of working Memory contents or for maintenance in the face of distracting information. This beneficial effect of a balance between prefrontal dopamine availability and D2 receptor density reveals the importance of considering epistasis effects and different working Memory subprocesses in genetic association studies.
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Effects of dopamine-related gene–gene interactions on working Memory Component processes
European Journal of Neuroscience, 2009Co-Authors: Christine Stelzel, Ulrike Basten, Christian Montag, Martin Reuter, Christian J. FiebachAbstract:Dopamine modulates complex cognitive functions like working Memory and cognitive control. It is widely accepted that an optimal level of prefrontal dopamine supports working Memory performance. In the present study we used a molecular genetic approach to test whether the optimal activity of the dopamine system for different Component processes of working Memory is additionally related to the availability of dopamine D2 receptors. We sought evidence for this assumption by investigating the interaction effect (epistasis) of variations in two dopaminergic candidate genes: the catechol-O-methyltransferase (COMT) Val(158)Met polymorphism, which has been shown to influence prefrontal dopamine concentration, and the DRD2/ANKK1-Taq-Ia polymorphism, which has been related to the density of D2 receptors. Our results show that COMT effects on working Memory performance are modulated by the DRD2/ANKK1-TAQ-Ia polymorphism and the specific working Memory Component process under investigation. Val- participants - supposedly characterized by increased prefrontal dopamine concentrations - outperformed Val+ participants in the manipulation of working Memory contents, but only when D2 receptor density could be considered to be high. No such effect was present for passive maintenance of working Memory contents or for maintenance in the face of distracting information. This beneficial effect of a balance between prefrontal dopamine availability and D2 receptor density reveals the importance of considering epistasis effects and different working Memory subprocesses in genetic association studies.
Pascale Schumann-bard - One of the best experts on this subject based on the ideXlab platform.
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Time decay of object, place and temporal order Memory in a paradigm assessing simultaneously episodic-like Memory Components in mice
Behavioural Brain Research, 2015Co-Authors: Hassina Belblidia, Abdelmalek Abdelouadoud, Christelle Jozet-alves, Hélène Dumas, Thomas Freret, Marianne Leger, Pascale Schumann-bardAbstract:A common trait of numerous Memory disorders is the impairment of episodic Memory. Episodic Memory is a delay-dependant Memory, especially associating three Components, the "what", "where" and "when" of a unique event. To investigate underlying mechanisms of such Memory, several tests, mainly based on object exploration behaviour, have been set up in rodents. Recently, a three-trial object recognition task has been proposed to evaluate simultaneously the different Components of episodic-like Memory in rodents. However, to date, the time course of each Memory Component in this paradigm is not known. We characterised here the time course of Memory decay in adult mice during the three-trial object recognition task, with inter-trial interval (ITI) ranging from 1 h to 4 h. We found that, with 1 hand 2 h, but not 4h ITI, mice spent more time to explore the displaced "old object" relative to the displaced "recent object", reflecting Memory for "what and when". Concomitantly, animals exhibited more exploration time for the displaced "old object" relative to the stationary "old object", reflecting Memory for "what and where". These results provide strong evidence that mice establish an integrated Memory for unique experience consisting of the "what", "where" and "when" that can persist until 2 h ITI. (C) 2015 Elsevier B.V. All rights reserved.
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Time decay of object, place and temporal order Memory in a paradigm assessing simultaneously episodic-like Memory Components in mice.
Behavioural Brain Research, 2015Co-Authors: Hassina Belblidia, Abdelmalek Abdelouadoud, Christelle Jozet-alves, Hélène Dumas, Thomas Freret, Marianne Leger, Pascale Schumann-bardAbstract:Abstract A common trait of numerous Memory disorders is the impairment of episodic Memory. Episodic Memory is a delay-dependant Memory, especially associating three Components, the “what”, “where” and “when” of a unique event. To investigate underlying mechanisms of such Memory, several tests, mainly based on object exploration behaviour, have been set up in rodents. Recently, a three-trial object recognition task has been proposed to evaluate simultaneously the different Components of episodic-like Memory in rodents. However, to date, the time course of each Memory Component in this paradigm is not known. We characterised here the time course of Memory decay in adult mice during the three-trial object recognition task, with inter-trial interval (ITI) ranging from 1 h to 4 h. We found that, with 1 h and 2 h, but not 4 h ITI, mice spent more time to explore the displaced “old object” relative to the displaced “recent object”, reflecting Memory for “what and when”. Concomitantly, animals exhibited more exploration time for the displaced “old object” relative to the stationary “old object”, reflecting Memory for “what and where”. These results provide strong evidence that mice establish an integrated Memory for unique experience consisting of the “what”, “where” and “when” that can persist until 2 h ITI.
Fergus I M Craik - One of the best experts on this subject based on the ideXlab platform.
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the role of spatial working Memory in inhibition of return evidence from divided attention tasks
Attention Perception & Psychophysics, 2003Co-Authors: Ala D Castel, Jay Pra, Fergus I M CraikAbstract:Inhibition of return (IOR) refers to a bias against returning attention to a location that has been recently attended. In the present experiments, we examined the role of working Memory in IOR by introducing secondary tasks (in the temporal interval between the cue and the target) that involved a working Memory Component. When the secondary task was nonspatial in nature (monitoring odd digits or adding digits), IOR was present, although overall reaction times were greater in the presence of the secondary task. When the task involved a spatial working Memory load (remembering the directionality of arrows or the orientation of objects), IOR was eliminated. However, when the participants had incentive to process the directionality of an arrow but did not have to use any Memory system, IOR persisted at peripheral locations. Overall, the results suggest that IOR is partially mediated by a spatial working Memory system.
Christine Stelzel - One of the best experts on this subject based on the ideXlab platform.
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effects of dopamine related gene gene interactions on working Memory Component processes
European Journal of Neuroscience, 2009Co-Authors: Christine Stelzel, Ulrike Basten, Christian Montag, Martin Reuter, Christian J. FiebachAbstract:Dopamine modulates complex cognitive functions like working Memory and cognitive control. It is widely accepted that an optimal level of prefrontal dopamine supports working Memory performance. In the present study we used a molecular genetic approach to test whether the optimal activity of the dopamine system for different Component processes of working Memory is additionally related to the availability of dopamine D2 receptors. We sought evidence for this assumption by investigating the interaction effect (epistasis) of variations in two dopaminergic candidate genes: the catechol-O-methyltransferase (COMT) Val(158)Met polymorphism, which has been shown to influence prefrontal dopamine concentration, and the DRD2/ANKK1-Taq-Ia polymorphism, which has been related to the density of D2 receptors. Our results show that COMT effects on working Memory performance are modulated by the DRD2/ANKK1-TAQ-Ia polymorphism and the specific working Memory Component process under investigation. Val- participants - supposedly characterized by increased prefrontal dopamine concentrations - outperformed Val+ participants in the manipulation of working Memory contents, but only when D2 receptor density could be considered to be high. No such effect was present for passive maintenance of working Memory contents or for maintenance in the face of distracting information. This beneficial effect of a balance between prefrontal dopamine availability and D2 receptor density reveals the importance of considering epistasis effects and different working Memory subprocesses in genetic association studies.
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Effects of dopamine-related gene–gene interactions on working Memory Component processes
European Journal of Neuroscience, 2009Co-Authors: Christine Stelzel, Ulrike Basten, Christian Montag, Martin Reuter, Christian J. FiebachAbstract:Dopamine modulates complex cognitive functions like working Memory and cognitive control. It is widely accepted that an optimal level of prefrontal dopamine supports working Memory performance. In the present study we used a molecular genetic approach to test whether the optimal activity of the dopamine system for different Component processes of working Memory is additionally related to the availability of dopamine D2 receptors. We sought evidence for this assumption by investigating the interaction effect (epistasis) of variations in two dopaminergic candidate genes: the catechol-O-methyltransferase (COMT) Val(158)Met polymorphism, which has been shown to influence prefrontal dopamine concentration, and the DRD2/ANKK1-Taq-Ia polymorphism, which has been related to the density of D2 receptors. Our results show that COMT effects on working Memory performance are modulated by the DRD2/ANKK1-TAQ-Ia polymorphism and the specific working Memory Component process under investigation. Val- participants - supposedly characterized by increased prefrontal dopamine concentrations - outperformed Val+ participants in the manipulation of working Memory contents, but only when D2 receptor density could be considered to be high. No such effect was present for passive maintenance of working Memory contents or for maintenance in the face of distracting information. This beneficial effect of a balance between prefrontal dopamine availability and D2 receptor density reveals the importance of considering epistasis effects and different working Memory subprocesses in genetic association studies.
Carlos A Zarate - One of the best experts on this subject based on the ideXlab platform.
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potential of pretreatment neural activity in the visual cortex during emotional processing to predict treatment response to scopolamine in major depressive disorder
JAMA Psychiatry, 2013Co-Authors: Maura L Furey, Wayne C Drevets, Elana M Hoffman, Erica Frankel, Andrew M Speer, Carlos A ZarateAbstract:Context The need for improved treatment options for patients with major depressive disorder (MDD) is critical. Faster-acting antidepressants and biomarkers that predict clinical response will facilitate treatment. Scopolamine produces rapid antidepressant effects and thus offers the opportunity to characterize potential biomarkers of treatment response within short periods. Objective To determine if baseline brain activity when processing emotional information can predict treatment response to scopolamine in MDD. Design A double-blind, placebo-controlled, crossover study together with repeated functional magnetic resonance imaging, acquired as participants performed face-identity and face-emotion working Memory tasks. Setting National Institute of Mental Health Division of Intramural Research Programs. Participants Fifteen currently depressed outpatients meeting DSM-IV criteria for recurrent MDD and 21 healthy participants, between 18 and 55 years of age. Main Outcome Measure The magnitude of treatment response to scopolamine (percentage of change in the Montgomery-Asberg Depression Rating Scale score between study end and baseline) was correlated with blood oxygen level–dependent (BOLD) signal associated with each working Memory Component (encode, maintenance, and test) for both identity and emotion tasks. Treatment response also was correlated with change in BOLD response (scopolamine vs baseline). Baseline activity was compared between healthy and MDD groups. Results Baseline BOLD response in the bilateral middle occipital cortex, selectively during the stimulus-processing Components of the emotion working Memory task (no correlation during the identity task), correlated with treatment response magnitude. Change in BOLD response following scopolamine administration in overlapping areas in the middle occipital cortex while performing the same task conditions also correlated with clinical response. Healthy controls showed higher activity in the same visual regions than patients with MDD during baseline. Conclusion These results implicate cholinergic and visual processing dysfunction in the pathophysiology of MDD and suggest that neural response in the visual cortex, selectively to emotional stimuli, may provide a useful biomarker for identifying patients who will respond favorably to scopolamine. Trial Registration clinicaltrials.gov Identifier: NCT00055575
