The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jennifer A Smith - One of the best experts on this subject based on the ideXlab platform.
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vortioxetine reduces bold signal during performance of the n back working Memory Task a randomised neuroimaging trial in remitted depressed patients and healthy controls
Molecular Psychiatry, 2018Co-Authors: Jennifer A Smith, Michael Browning, Silke Conen, Richard Smallman, Jeppe Buchbjerg, K G Larsen, C K Olsen, S R Christensen, G. R. Dawson, J. F William DeakinAbstract:Vortioxetine reduces BOLD signal during performance of the N-back working Memory Task: a randomised neuroimaging trial in remitted depressed patients and healthy controls
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vortioxetine reduces bold signal during performance of the n back working Memory Task a randomised neuroimaging trial in remitted depressed patients and healthy controls
Molecular Psychiatry, 2018Co-Authors: Jennifer A Smith, Michael Browning, Silke Conen, Jeppe Buchbjerg, C K Olsen, S R Christensen, G. R. Dawson, Richard Smallman, K G Larsen, J F W DeakinAbstract:Cognitive dysfunction is common in depression during both acute episodes and remission. Vortioxetine is a novel multimodal antidepressant that has improved cognitive function including executive function in depressed patients in randomised placebo-controlled clinical trials. However, it is unclear whether vortioxetine is able to target directly the neural circuitry implicated in the cognitive deficits in depression. Remitted depressed (n=48) and healthy volunteers (n=48) were randomised to receive 14 days treatment with 20 mg vortioxetine or placebo in a double-blind design. The effects of treatment on functional magnetic resonance imaging responses during an N-back working Memory Task were assessed at baseline and at the end of treatment. Neuropsychological measures of executive function, speed and information processing, attention and learning and Memory were examined with the Trail Making Test (TMT), Rey Auditory Learning Test and Digit Symbol Substitution Test before and after treatment; subjective cognitive function was assessed using the Perceived Deficits Questionnaire (PDQ). Compared with placebo, vortioxetine reduced activation in the right dorsolateral prefrontal cortex and left hippocampus during the N-back Task compared with placebo. Vortioxetine also increased TMT-A performance and self-reported cognitive function on the PDQ. These effects were seen across both subject groups. Vortioxetine modulates neural responses across a circuit subserving working Memory in a direction opposite to the changes described in depression, when performance is maintained. This study provides evidence that vortioxetine has direct effects on the neural circuitry supporting cognitive function that can be dissociated from its effects on the mood symptoms of depression.
Douglas C. Noll - One of the best experts on this subject based on the ideXlab platform.
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temporal dynamics of brain activation during a working Memory Task
Nature, 1997Co-Authors: Jonathan D. Cohen, Douglas C. Noll, Todd S Braver, William M Perlstein, Leigh E Nystrom, John Jonides, Edward E SmithAbstract:Working Memory is responsible for the short-term storage and online manipulation of information necessary for higher cognitive functions, such as language, planning and problem-solving. Traditionally, working Memory has been divided into two types of processes: executive control (governing the encoding manipulation and retrieval of information in working Memory) and active maintenance (keeping information available 'online'). It has also been proposed that these two types of processes may be subserved by distinct cortical structures, with the prefrontal cortex housing the executive control processes, and more posterior regions housing the content-specific buffers (for example verbal versus visuospatial) responsible for active maintenance. However, studies in non-human primates suggest that dorsolateral regions of the prefrontal cortex may also be involved in active maintenance. We have used functional magnetic resonance imaging to examine brain activation in human subjects during performance of a working Memory Task. We used the temporal resolution of this technique to examine the dynamics of regional activation, and to show that prefrontal cortex along with parietal cortex appears to play a role in active maintenance.
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Activation of prefrontal cortex in children during a nonspatial working Memory Task with functional MRI.
NeuroImage, 1995Co-Authors: B. J. Casey, Jonathan D. Cohen, Douglas C. Noll, Peter Jezzard, Robert Turner, Rolf J. Trainor, Jay N. Giedd, Debra Kaysen, Lucy Hertz-pannier, Judith L. RapoportAbstract:Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of prefrontal cortex in prepubertal children during performance of a nonspatial working Memory Task. The children observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison Task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Location of activation closely approximated that observed in a recent fMRI study with adults using exactly the same Task. Activation of the inferior and middle frontal gyri was reliably observed within individual subjects during performance of the working Memory Task relative to the comparison Task. Activation increased and decreased with a time course that was highly consistent with the Task manipulations and correlated with behavioral performance. To our knowledge, this study is one of the first to demonstrate the applicability of fMRI to a normative developmental population. Issues of age dependence of the hemodynamic responses of fMRI are discussed.
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activation of the prefrontal cortex in a nonspatial working Memory Task with functional mri
Human Brain Mapping, 1994Co-Authors: Jonathan D. Cohen, B. J. Casey, Douglas C. Noll, Steven D Forman, Todd S Braver, David ServanschreiberAbstract:Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of the prefrontal cortex during performance of subjects in a nonspatial working Memory Task. Subjects observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison Task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Functional scanning was performed using a newly developed spiral scan image acquisition technique that provides high-resolution, multislice scanning at approximately five times the rate usually possible on conventional equipment (an average of one image per second). Using these methods, activation of the middle and inferior frontal gyri was reliably observed within individual subjects during performance of the working Memory Task relative to the comparison Task. Effect sizes (2–4%) closely approximated those that have been observed within primary sensory and motor cortices using similar fMRI techniques. Furthermore, activation increased and decreased with a time course that was highly consistent with the Task manipulations. These findings corroborate the results of positron emission tomography studies, which suggest that the prefrontal cortex is engaged by Tasks that rely on working Memory. Furthermore, they demonstrate the applicability of newly developed fMRI techniques using conventional scanners to study the associative cortex in individual subjects. © 1994 Wiley-Liss, Inc.
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Activation of the prefrontal cortex in a nonspatial working Memory Task with functional MRI
Human brain mapping, 1994Co-Authors: Jonathan D. Cohen, B. J. Casey, Steven D Forman, Todd S Braver, David Servan-schreiber, Douglas C. NollAbstract:Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of the prefrontal cortex during performance of subjects in a nonspatial working Memory Task. Subjects observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison Task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Functional scanning was performed using a newly developed spiral scan image acquisition technique that provides high-resolution, multislice scanning at approximately five times the rate usually possible on conventional equipment (an average of one image per second). Using these methods, activation of the middle and inferior frontal gyri was reliably observed within individual subjects during performance of the working Memory Task relative to the comparison Task. Effect sizes (2-4%) closely approximated those that have been observed within primary sensory and motor cortices using similar fMRI techniques. Furthermore, activation increased and decreased with a time course that was highly consistent with the Task manipulations. These findings corroborate the results of positron emission tomography studies, which suggest that the prefrontal cortex is engaged by Tasks that rely on working Memory. Furthermore, they demonstrate the applicability of newly developed fMRI techniques using conventional scanners to study the associative cortex in individual subjects. © 1994 Wiley-Liss, Inc.
Nikolaos Pitsikas - One of the best experts on this subject based on the ideXlab platform.
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the nitric oxide releasing derivative of ferulic acid ncx 2057 antagonized delay dependent and scopolamine induced performance deficits in a recognition Memory Task in the rat
Progress in Neuro-psychopharmacology & Biological Psychiatry, 2010Co-Authors: Antonios Boultadakis, Panagiotis Liakos, Nikolaos PitsikasAbstract:Nitric oxide (NO) is considered as an intracellular messenger in the brain. Its involvement in learning and Memory processes has been proposed. The present study was designed to investigate the effects of the NO-releasing derivative of ferulic acid NCX 2057 on rats' recognition Memory. For this purpose the object recognition Task was selected. Post-training treatment with NCX 2057 (10 mg/kg, i.p.) and with the reference compound, the NO donor molsidomine (4 mg/kg, i.p.), antagonized extinction of recognition Memory in the normal rat. Conversely, animals treated with the parent compound ferulic acid (1.9, 6.2 and 18.7 mg/kg, i.p.) failed to do so. In addition, NCX 2057 (3 and 10 mg/kg, i.p) reversed the scopolamine (0.2 mg/kg, s.c.)-induced performance deficits in this recognition Memory Task. These results indicate that this novel NO donor may modulate different aspects of recognition Memory and suggest that an interaction between the nitrergic and cholinergic system is relevant to cognition.
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the nitric oxide no donor molsidomine antagonizes scopolamine and l name induced performance deficits in a spatial Memory Task in the rat
Behavioural Brain Research, 2009Co-Authors: Nikolaos PitsikasAbstract:Nitric oxide (NO) is considered as an intracellular messenger in the brain. Its involvement in learning and Memory processes has been proposed. Compounds that inhibit NO synthase (NOS), the key synthesizing enzyme, may inhibit cognition, while NO donors may facilitate it. The present study was designed to investigate the effects of the NO donor molsidomine on rats' spatial Memory. Thus, the ability of molsidomine (2 and 4 mg/kg, i.p.) in attenuating spatial Memory deficits produced either by the muscarinic receptor antagonist scopolamine (0.2 mg/kg, s.c.) or by the NOS inhibitor L-NAME (30 mg/kg, i.p.) was assessed. For this aim, the object location test was selected. In the first study, molsidomine (4 mg/kg) counteracted the scopolamine-induced performance deficits in this spatial Memory Task. Subsequently, pre-training administration of molsidomine (4 mg/kg but not 2 mg/kg) antagonized also the impairing effects produced by L-NAME in the object location paradigm. These results indicate that NO is involved in spatial recognition Memory and that an NO component modulates the effects of the cholinergic system on spatial Memory.
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molsidomine antagonizes l name induced acquisition deficits in a recognition Memory Task in the rat
Pharmacological Research, 2003Co-Authors: Nikolaos Pitsikas, Antonello E Rigamonti, S M Bonomo, Silvano G Cella, Eugenio E MullerAbstract:Abstract The present study was designed to investigate the role of nitric oxide (NO) on the acquisition of a recognition Memory Task in the rat. For this purpose, the effects on Memory exerted by pre-training administration of the NO synthase inhibitor L-NAME ( N ω -nitro- l -arginine methyl ester) and the NO donor molsidomine ( N -[ethoxycarbonyl]-3-[4-morpholinosydnomine]) were assessed by using the object recognition Task, a working Memory paradigm based on the differential exploration of a new and familiar object. In a first dose–response study, it was found that L-NAME (10, 30, and 60 mg kg −1 , i.p.) at 30 but not at 10 mg kg −1 disrupted animals performance, whereas the dose of 60 mg kg −1 induced side effects. Molsidomine (2 and 4 mg kg −1 , i.p.) at 4 but not at 2 mg kg −1 , antagonized the L-NAME-induced performance deficits. These results indicate that NO is involved in the acquisition of a recognition Memory Task.
Jonathan D. Cohen - One of the best experts on this subject based on the ideXlab platform.
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temporal dynamics of brain activation during a working Memory Task
Nature, 1997Co-Authors: Jonathan D. Cohen, Douglas C. Noll, Todd S Braver, William M Perlstein, Leigh E Nystrom, John Jonides, Edward E SmithAbstract:Working Memory is responsible for the short-term storage and online manipulation of information necessary for higher cognitive functions, such as language, planning and problem-solving. Traditionally, working Memory has been divided into two types of processes: executive control (governing the encoding manipulation and retrieval of information in working Memory) and active maintenance (keeping information available 'online'). It has also been proposed that these two types of processes may be subserved by distinct cortical structures, with the prefrontal cortex housing the executive control processes, and more posterior regions housing the content-specific buffers (for example verbal versus visuospatial) responsible for active maintenance. However, studies in non-human primates suggest that dorsolateral regions of the prefrontal cortex may also be involved in active maintenance. We have used functional magnetic resonance imaging to examine brain activation in human subjects during performance of a working Memory Task. We used the temporal resolution of this technique to examine the dynamics of regional activation, and to show that prefrontal cortex along with parietal cortex appears to play a role in active maintenance.
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Activation of prefrontal cortex in children during a nonspatial working Memory Task with functional MRI.
NeuroImage, 1995Co-Authors: B. J. Casey, Jonathan D. Cohen, Douglas C. Noll, Peter Jezzard, Robert Turner, Rolf J. Trainor, Jay N. Giedd, Debra Kaysen, Lucy Hertz-pannier, Judith L. RapoportAbstract:Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of prefrontal cortex in prepubertal children during performance of a nonspatial working Memory Task. The children observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison Task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Location of activation closely approximated that observed in a recent fMRI study with adults using exactly the same Task. Activation of the inferior and middle frontal gyri was reliably observed within individual subjects during performance of the working Memory Task relative to the comparison Task. Activation increased and decreased with a time course that was highly consistent with the Task manipulations and correlated with behavioral performance. To our knowledge, this study is one of the first to demonstrate the applicability of fMRI to a normative developmental population. Issues of age dependence of the hemodynamic responses of fMRI are discussed.
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activation of the prefrontal cortex in a nonspatial working Memory Task with functional mri
Human Brain Mapping, 1994Co-Authors: Jonathan D. Cohen, B. J. Casey, Douglas C. Noll, Steven D Forman, Todd S Braver, David ServanschreiberAbstract:Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of the prefrontal cortex during performance of subjects in a nonspatial working Memory Task. Subjects observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison Task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Functional scanning was performed using a newly developed spiral scan image acquisition technique that provides high-resolution, multislice scanning at approximately five times the rate usually possible on conventional equipment (an average of one image per second). Using these methods, activation of the middle and inferior frontal gyri was reliably observed within individual subjects during performance of the working Memory Task relative to the comparison Task. Effect sizes (2–4%) closely approximated those that have been observed within primary sensory and motor cortices using similar fMRI techniques. Furthermore, activation increased and decreased with a time course that was highly consistent with the Task manipulations. These findings corroborate the results of positron emission tomography studies, which suggest that the prefrontal cortex is engaged by Tasks that rely on working Memory. Furthermore, they demonstrate the applicability of newly developed fMRI techniques using conventional scanners to study the associative cortex in individual subjects. © 1994 Wiley-Liss, Inc.
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Activation of the prefrontal cortex in a nonspatial working Memory Task with functional MRI
Human brain mapping, 1994Co-Authors: Jonathan D. Cohen, B. J. Casey, Steven D Forman, Todd S Braver, David Servan-schreiber, Douglas C. NollAbstract:Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of the prefrontal cortex during performance of subjects in a nonspatial working Memory Task. Subjects observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison Task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Functional scanning was performed using a newly developed spiral scan image acquisition technique that provides high-resolution, multislice scanning at approximately five times the rate usually possible on conventional equipment (an average of one image per second). Using these methods, activation of the middle and inferior frontal gyri was reliably observed within individual subjects during performance of the working Memory Task relative to the comparison Task. Effect sizes (2-4%) closely approximated those that have been observed within primary sensory and motor cortices using similar fMRI techniques. Furthermore, activation increased and decreased with a time course that was highly consistent with the Task manipulations. These findings corroborate the results of positron emission tomography studies, which suggest that the prefrontal cortex is engaged by Tasks that rely on working Memory. Furthermore, they demonstrate the applicability of newly developed fMRI techniques using conventional scanners to study the associative cortex in individual subjects. © 1994 Wiley-Liss, Inc.
J. F William Deakin - One of the best experts on this subject based on the ideXlab platform.
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vortioxetine reduces bold signal during performance of the n back working Memory Task a randomised neuroimaging trial in remitted depressed patients and healthy controls
Molecular Psychiatry, 2018Co-Authors: Jennifer A Smith, Michael Browning, Silke Conen, Richard Smallman, Jeppe Buchbjerg, K G Larsen, C K Olsen, S R Christensen, G. R. Dawson, J. F William DeakinAbstract:Vortioxetine reduces BOLD signal during performance of the N-back working Memory Task: a randomised neuroimaging trial in remitted depressed patients and healthy controls
