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Gregorio I, Mereu M, Contarini G, Bello L, Semplicini C, Burgio F, Russo L, Sut S, Dall'Acqua S, Braghetta P, Semenza C, Pegoraro E, Papaleo F, Bonaldo P, Cescon M. Collagen VI deficiency causes behavioral abnormalities and cortical dopaminergic dysfunction. Dis Model Mech 2022; 15:276265. [PMID: 35946603 PMCID: PMC9548377 DOI: 10.1242/dmm.049481] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 07/29/2022] [Indexed: 11/20/2022] Open
Abstract
Mutations of genes coding for Collagen VI (COL6) cause muscle diseases, including Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM). Although more recently COL6 genetic variants were linked to brain pathologies, the impact of COL6 deficiency in brain function is still largely unknown. Here, a thorough behavioral characterization of COL6 null (Col6a1-/-) mice unexpectedly revealed that COL6 deficiency leads to a significant impairment in sensorimotor gating and memory/attention functions. In keeping with these behavioral abnormalities, Col6a1-/- mice displayed alterations in dopaminergic signalling, primarily in the prefrontal cortex (PFC). In vitro co-culture of SH-SY5Y neural cells with primary meningeal fibroblasts from wild-type and Col6a1-/- mice confirmed a direct link between COL6 ablation and defective dopaminergic activity, through a mechanism involving the inability of meningeal cells to sustain dopaminergic differentiation. Finally, patients affected by COL6-related myopathies were evaluated with an ad hoc neuropsychological protocol, revealing distinctive defects in attentional control abilities. Altogether, these findings point at a novel role for COL6 in the proper maintenance of dopamine circuitry function and its related neurobehavioral features in both mice and humans.
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Affiliation(s)
- Ilaria Gregorio
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - Maddalena Mereu
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Italy.,Genetics of Cognition Laboratory, Neuroscience Area, Istituto Italiano di Tecnologia, 16163, Genova, Italy
| | - Gabriella Contarini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Italy.,Genetics of Cognition Laboratory, Neuroscience Area, Istituto Italiano di Tecnologia, 16163, Genova, Italy
| | - Luca Bello
- ERN Neuromuscular Center, Department of Neurosciences, University of Padova, 35129 Padova, Italy
| | - Claudio Semplicini
- ERN Neuromuscular Center, Department of Neurosciences, University of Padova, 35129 Padova, Italy
| | | | - Loris Russo
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - Stefania Sut
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Italy
| | - Stefano Dall'Acqua
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Italy
| | - Paola Braghetta
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - Carlo Semenza
- ERN Neuromuscular Center, Department of Neurosciences, University of Padova, 35129 Padova, Italy.,IRCCS San Camillo Hospital, 30126 Venice, Italy
| | - Elena Pegoraro
- ERN Neuromuscular Center, Department of Neurosciences, University of Padova, 35129 Padova, Italy
| | - Francesco Papaleo
- Genetics of Cognition Laboratory, Neuroscience Area, Istituto Italiano di Tecnologia, 16163, Genova, Italy
| | - Paolo Bonaldo
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - Matilde Cescon
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
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Arnoriaga-Rodríguez M, Mayneris-Perxachs J, Contreras-Rodríguez O, Burokas A, Ortega-Sanchez JA, Blasco G, Coll C, Biarnés C, Castells-Nobau A, Puig J, Garre-Olmo J, Ramos R, Pedraza S, Brugada R, Vilanova JC, Serena J, Barretina J, Gich J, Pérez-Brocal V, Moya A, Fernández-Real X, Ramio-Torrentà L, Pamplona R, Sol J, Jové M, Ricart W, Portero-Otin M, Maldonado R, Fernández-Real JM. Obesity-associated deficits in inhibitory control are phenocopied to mice through gut microbiota changes in one-carbon and aromatic amino acids metabolic pathways. Gut 2021; 70:2283-2296. [PMID: 33514598 PMCID: PMC8588299 DOI: 10.1136/gutjnl-2020-323371] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/16/2020] [Accepted: 01/08/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Inhibitory control (IC) is critical to keep long-term goals in everyday life. Bidirectional relationships between IC deficits and obesity are behind unhealthy eating and physical exercise habits. METHODS We studied gut microbiome composition and functionality, and plasma and faecal metabolomics in association with cognitive tests evaluating inhibitory control (Stroop test) and brain structure in a discovery (n=156), both cross-sectionally and longitudinally, and in an independent replication cohort (n=970). Faecal microbiota transplantation (FMT) in mice evaluated the impact on reversal learning and medial prefrontal cortex (mPFC) transcriptomics. RESULTS An interplay among IC, brain structure (in humans) and mPFC transcriptomics (in mice), plasma/faecal metabolomics and the gut metagenome was found. Obesity-dependent alterations in one-carbon metabolism, tryptophan and histidine pathways were associated with IC in the two independent cohorts. Bacterial functions linked to one-carbon metabolism (thyX,dut, exodeoxyribonuclease V), and the anterior cingulate cortex volume were associated with IC, cross-sectionally and longitudinally. FMT from individuals with obesity led to alterations in mice reversal learning. In an independent FMT experiment, human donor's bacterial functions related to IC deficits were associated with mPFC expression of one-carbon metabolism-related genes of recipient's mice. CONCLUSION These results highlight the importance of targeting obesity-related impulsive behaviour through the induction of gut microbiota shifts.
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Affiliation(s)
- María Arnoriaga-Rodríguez
- Department of Diabetes, Endocrinology and Nutrition, Dr. Josep Trueta University Hospital, Girona, Spain
- Nutrition, Eumetabolism and Health Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- CIBER Pathophysiology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
| | - Jordi Mayneris-Perxachs
- Department of Diabetes, Endocrinology and Nutrition, Dr. Josep Trueta University Hospital, Girona, Spain
- Nutrition, Eumetabolism and Health Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- CIBER Pathophysiology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
| | - Oren Contreras-Rodríguez
- Nutrition, Eumetabolism and Health Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- Department of Psychiatry, Bellvitge University Hospital, Bellvitge Biomedical Research Institute (IDIBELL) and CIBERSAM, Barcelona, Spain
| | - Aurelijus Burokas
- Laboratory of Neuropharmacology, Deparment of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
- Present address: Institute of Biochemistry, Life Sciences Center, Vilnius University, Saulėtekio av. 7, LT-10257 Vilnius, Lithuania
| | - Juan-Antonio Ortega-Sanchez
- Laboratory of Neuropharmacology, Deparment of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Gerard Blasco
- Institute of Diagnostic Imaging (IDI)-Research Unit (IDIR), Parc Sanitari Pere Virgili, Barcelona, Spain
- Medical Imaging, Girona Biomedical Research Institute (IdibGi), Girona, Spain
| | - Claudia Coll
- Neuroimmunology and Multiple Sclerosis Unit, Deparment of Neurology, Dr. Josep Trueta University Hospital, Girona, Spain
| | - Carles Biarnés
- Medical Imaging, Girona Biomedical Research Institute (IdibGi), Girona, Spain
| | - Anna Castells-Nobau
- Department of Diabetes, Endocrinology and Nutrition, Dr. Josep Trueta University Hospital, Girona, Spain
- Nutrition, Eumetabolism and Health Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- CIBER Pathophysiology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
| | - Josep Puig
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Institute of Diagnostic Imaging (IDI)-Research Unit (IDIR), Parc Sanitari Pere Virgili, Barcelona, Spain
- Medical Imaging, Girona Biomedical Research Institute (IdibGi), Girona, Spain
| | - Josep Garre-Olmo
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Research Group on Aging, Health and Disability, Girona Biomedical Research Institute, Health Assistance Institute, Girona, Spain
| | - Rafel Ramos
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Catalonia, Spain
| | - Salvador Pedraza
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Medical Imaging, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- Deparment of Radiology, Dr. Josep Trueta University Hospital, Girona, Spain
| | - Ramon Brugada
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Cardiovascular Genetics Center, CIBER-CV, Girona Biomedical Research Institute (IDIBGI), Dr. Josep Trueta University Hospital, Girona, Spain
- Biomedical Research Networking Center on Cardiovascular Diseases (CIBERCV), Madrid, Spain
- Deparment of Cardiology, Dr. Josep Trueta University Hospital, Girona, Spain
| | - Joan C Vilanova
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Medical Imaging, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- Deparment of Radiology, Dr. Josep Trueta University Hospital, Girona, Spain
| | - Joaquín Serena
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Department of Neurology, Dr. Josep Trueta University Hospital, Girona Biomedical Research Institute (IDIBGI), Girona, Spain
| | - Jordi Barretina
- Girona Biomedical Research Institute (IdibGi), Dr. Josep Trueta University Hospital, Girona, Spain
| | - Jordi Gich
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Neurodegeneration and Neuroinflammation Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
| | - Vicente Pérez-Brocal
- Joint Investigation Unit of FISABIO and I2Sysbio, University of València and CSIC, Valencia, Spain
- Biomedical Research Networking Center for Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Andrés Moya
- Joint Investigation Unit of FISABIO and I2Sysbio, University of València and CSIC, Valencia, Spain
- Biomedical Research Networking Center for Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Xavier Fernández-Real
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Lluis Ramio-Torrentà
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
- Neuroimmunology and Multiple Sclerosis Unit, Deparment of Neurology, Dr. Josep Trueta University Hospital, Girona, Spain
- Department of Neurology, Dr. Josep Trueta University Hospital, Girona Biomedical Research Institute (IDIBGI), Girona, Spain
- Neurodegeneration and Neuroinflammation Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- Red Española de Esclerosis Múltiple (REEM), Madrid, Spain
| | - Reinald Pamplona
- Metabolic Physiopathology Research Group, Experimental Medicine Department, Lleida University-Lleida Biochemical Research Institute (UdL-IRBLleida), Lleida, Spain
| | - Joaquim Sol
- Metabolic Physiopathology Research Group, Experimental Medicine Department, Lleida University-Lleida Biochemical Research Institute (UdL-IRBLleida), Lleida, Spain
- Institut Català de la Salut, Atenció Primària, Lleida, Spain
- Research Support Unit Lleida, Fundació Institut Universitari per a la recerca a l'Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Lleida, Spain
| | - Mariona Jové
- Metabolic Physiopathology Research Group, Experimental Medicine Department, Lleida University-Lleida Biochemical Research Institute (UdL-IRBLleida), Lleida, Spain
| | - Wifredo Ricart
- Department of Diabetes, Endocrinology and Nutrition, Dr. Josep Trueta University Hospital, Girona, Spain
- Nutrition, Eumetabolism and Health Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- CIBER Pathophysiology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
| | - Manuel Portero-Otin
- Metabolic Physiopathology Research Group, Experimental Medicine Department, Lleida University-Lleida Biochemical Research Institute (UdL-IRBLleida), Lleida, Spain
| | - Rafael Maldonado
- Laboratory of Neuropharmacology, Deparment of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - Jose Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Dr. Josep Trueta University Hospital, Girona, Spain
- Nutrition, Eumetabolism and Health Group, Girona Biomedical Research Institute (IdibGi), Girona, Spain
- CIBER Pathophysiology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
- Deparment of Medical Sciences, Faculty of Medicine, University of Girona, Girona, Spain
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Multimodal investigation of dopamine D 2/D 3 receptors, default mode network suppression, and cognitive control in cocaine-use disorder. Neuropsychopharmacology 2021; 46:316-324. [PMID: 33007778 PMCID: PMC7852666 DOI: 10.1038/s41386-020-00874-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/17/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022]
Abstract
Stimulant-use disorders have been associated with lower availability of dopamine type-2 receptors (D2R) and greater availability of type-3 receptors (D3R). Links between D2R levels, cognitive performance, and suppression of the default mode network (DMN) during executive functioning have been observed in healthy and addicted populations; however, there is limited evidence regarding a potential role of elevated D3R in influencing cognitive control processes in groups with and without addictions. Sixteen individuals with cocaine-use disorder (CUD) and 16 healthy comparison (HC) participants completed [11C]-(+)-PHNO PET imaging of D2R and D3R availability and fMRI during a Stroop task of cognitive control. Independent component analysis was performed on fMRI data to assess DMN suppression during Stroop performance. In HC individuals, lower D2R-related binding in the dorsal putamen was associated with improved task performance and greater DMN suppression. By comparison, in individuals with CUD, greater D3R-related binding in the substantia nigra was associated with improved performance and greater DMN suppression. Exploratory moderated-mediation analyses indicated that DMN suppression was associated with Stroop performance indirectly through D2R in HC and D3R in CUD participants, and these indirect effects were different between groups. To our knowledge, this is the first evidence of a dissociative and potentially beneficial role of elevated D3R availability in executive functioning in cocaine-use disorder.
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Flashman LA, McDonald BC, Ford JC, Kenny RM, Andrews KD, Saykin AJ, McAllister TW. Differential Effects of Pergolide and Bromocriptine on Working Memory Performance and Brain Activation after Mild Traumatic Brain Injury. J Neurotrauma 2020; 38:225-234. [PMID: 32635808 DOI: 10.1089/neu.2020.7087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Dopamine D1 and D2 receptors differ with respect to patterns of regional brain distribution and behavioral effects. Pre-clinical work suggests that D1 agonists enhance working memory, but the absence of selective D1 agonists has constrained using this approach in humans. This study examines working memory performance in mild traumatic brain injury (mTBI) patients when given pergolide, a mixed D1/D2 agonist, compared with bromocriptine, a selective D2 agonist. Fifteen individuals were studied 1 month after mTBI and compared with 17 healthy controls. At separate visits, participants were administered 1.25 mg bromocriptine or 0.05 mg pergolide prior to functional magnetic resonance imaging (MRI) using a working memory task (visual-verbal n-back). Results indicated a significant group-by-drug interaction for mean performance across n-back task conditions, where the mTBI group showed better performance on pergolide relative to bromocriptine, whereas controls showed the opposite pattern. There was also a significant effect of diagnosis, where mTBI patients performed worse than controls, particularly while on bromocriptine, as shown in our prior work. Functional MRI activation during the most challenging task condition (3-back > 0-back contrast) showed a significant group-by-drug interaction, with the mTBI group showing increased activation relative to controls in working memory circuitry while on pergolide, including in the left inferior frontal gyrus. Across participants there was a positive correlation between change in activation in this region and change in performance between drug conditions. Results suggest that activation of the D1 receptor may improve working memory performance after mTBI. This has implications for the development of pharmacological strategies to treat cognitive deficits after mTBI.
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Affiliation(s)
- Laura A Flashman
- Department of Neurology, Wake Forest Medical School and Wake Forest Baptist Medical Center, Winston-Salem, North Carolina, USA
| | - Brenna C McDonald
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - James C Ford
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Rachel M Kenny
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Katharine D Andrews
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Thomas W McAllister
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Woodcock EA, Zakiniaeiz Y, Morris ED, Cosgrove KP. Sex and the dopaminergic system: Insights from addiction studies. HANDBOOK OF CLINICAL NEUROLOGY 2020; 175:141-165. [PMID: 33008522 PMCID: PMC11267480 DOI: 10.1016/b978-0-444-64123-6.00011-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sex differences are present in psychiatric disorders associated with disrupted dopamine function, and thus, sex differences in dopamine neurobiology may underlie these clinical disparities. In this chapter, we review sex differences in the dopaminergic system with a focus on substance use disorders, especially tobacco smoking, as our exemplar disorder. This chapter is organized into five sections describing sex differences in the dopaminergic system: (1) neurobiology, (2) role of sex hormones, (3) genetic underpinnings, (4) cognitive function, and (5) influence on addiction. In each section, we provide an overview of the topic area, summarize sex differences identified to date, highlight addiction research, especially clinical neuroimaging studies, and suggest avenues for future research.
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Affiliation(s)
- Eric A Woodcock
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States; Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States; Yale Positron Emission Tomography (PET) Center, Yale University, New Haven, CT, United States
| | - Yasmin Zakiniaeiz
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States; Yale Positron Emission Tomography (PET) Center, Yale University, New Haven, CT, United States
| | - Evan D Morris
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States; Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States; Department of Biomedical Engineering, Yale University, New Haven, CT, United States; Department of Biomedical Engineering, Yale University, New Haven, CT, United States; Invicro, LLC, New Haven, CT, United States
| | - Kelly P Cosgrove
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States; Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States; Yale Positron Emission Tomography (PET) Center, Yale University, New Haven, CT, United States.
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MK-801-induced deficits in social recognition in rats: reversal by aripiprazole, but not olanzapine, risperidone, or cannabidiol. Behav Pharmacol 2016; 26:748-65. [PMID: 26287433 DOI: 10.1097/fbp.0000000000000178] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Deficiencies in social activities are hallmarks of numerous brain disorders. With respect to schizophrenia, social withdrawal belongs to the category of negative symptoms and is associated with deficits in the cognitive domain. Here, we used the N-methyl-D-aspartate receptor antagonist dizocilpine (MK-801) for induction of social withdrawal in rats and assessed the efficacy of several atypical antipsychotics with different pharmacological profiles as putative treatment. In addition, we reasoned that the marijuana constituent cannabidiol (CBD) may provide benefit or could be proposed as an adjunct treatment in combination with antipsychotics. Hooded Lister rats were tested in the three-chamber version for social interaction, with an initial novelty phase, followed after 3 min by a short-term recognition memory phase. No drug treatment affected sociability. However, distinct effects on social recognition were revealed. MK-801 reduced social recognition memory at all doses (>0.03 mg/kg). Predosing with aripiprazole dose-dependently (2 or 10 mg/kg) prevented the memory decline, but doses of 0.1 mg/kg risperidone or 1 mg/kg olanzapine did not. Intriguingly, CBD impaired social recognition memory (12 and 30 mg/kg) but did not rescue the MK-801-induced deficits. When CBD was combined with protective doses of aripiprazole (CBD-aripiprazole at 12 : or 5 : 2 mg/kg) the benefit of the antipsychotic was lost. At the same time, activity-related changes in behaviour were excluded as underlying reasons for these pharmacological effects. Collectively, the combined activity of aripiprazole on dopamine D2 and serotonin 5HT1A receptors appears to provide a significant advantage over risperidone and olanzapine with respect to the rescue of cognitive deficits reminiscent of schizophrenia. The differential pharmacological properties of CBD, which are seemingly beneficial in human patients, did not back-translate and rescue the MK-801-induced social memory deficit.
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Gallant H, Vo A, Seergobin KN, MacDonald PA. Pramipexole Impairs Stimulus-Response Learning in Healthy Young Adults. Front Neurosci 2016; 10:374. [PMID: 27594823 PMCID: PMC4990534 DOI: 10.3389/fnins.2016.00374] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/02/2016] [Indexed: 01/31/2023] Open
Abstract
Dopaminergic therapy has paradoxical effects on cognition in Parkinson's disease (PD) patients, with some functions worsened and others improved. The dopamine overdose hypothesis is proposed as an explanation for these opposing effects of medication taking into account the varying levels of dopamine within different brain regions in PD. The detrimental effects of medication on cognition have been attributed to exogenous dopamine overdose in brain regions with spared dopamine levels in PD. It has been demonstrated that learning is most commonly worsened by dopaminergic medication. The current study aimed to investigate whether the medication-related learning impairment exhibited in PD patients is due to a main effect of medication by evaluating the dopamine overdose hypothesis in healthy young adults. Using a randomized, double-blind, placebo-controlled design, 40 healthy young undergraduate students completed a stimulus-response learning task. Half of the participants were treated with 0.5 mg of pramipexole, a dopamine agonist, whereas the other half were treated with a placebo. We found that stimulus-response learning was significantly impaired in participants on pramipexole relative to placebo controls. These findings are consistent with the dopamine overdose hypothesis and suggest that dopaminergic medication impairs learning independent of PD pathology. Our results have important clinical implications for conditions treated with pramipexole, particularly PD, restless leg syndrome, some forms of dystonia, and potentially depression.
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Affiliation(s)
- Haley Gallant
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada
| | - Andrew Vo
- The Brain and Mind Institute, University of Western OntarioLondon, ON, Canada; Department of Psychology, University of Western OntarioLondon, ON, Canada
| | - Ken N Seergobin
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada
| | - Penny A MacDonald
- The Brain and Mind Institute, University of Western OntarioLondon, ON, Canada; Department of Psychology, University of Western OntarioLondon, ON, Canada; Department of Clinical Neurological Sciences, University of Western OntarioLondon, ON, Canada
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An investigation into aripiprazole's partial D₂ agonist effects within the dorsolateral prefrontal cortex during working memory in healthy volunteers. Psychopharmacology (Berl) 2016; 233:1415-26. [PMID: 26900078 PMCID: PMC4819596 DOI: 10.1007/s00213-016-4234-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/03/2016] [Indexed: 11/29/2022]
Abstract
RATIONALE Working memory impairments in schizophrenia have been attributed to dysfunction of the dorsolateral prefrontal cortex (DLPFC) which in turn may be due to low DLPFC dopamine innervation. Conventional antipsychotic drugs block DLPFC D2 receptors, and this may lead to further dysfunction and working memory impairments. Aripiprazole is a D2 receptor partial agonist hypothesised to enhance PFC dopamine functioning, possibly improving working memory. OBJECTIVES We probed the implications of the partial D2 receptor agonist actions of aripiprazole within the DLPFC during working memory. Investigations were carried out in healthy volunteers to eliminate confounds of illness or medication status. Aripiprazole's prefrontal actions were compared with the D2/5-HT2A blocker risperidone to separate aripiprazole's unique prefrontal D2 agonist actions from its serotinergic and striatal D2 actions that it shares with risperidone. METHOD A double-blind, placebo-controlled, parallel design was implemented. Participants received a single dose of either 5 mg aripiprazole, 1 mg risperidone or placebo before performing the n-back task whilst undergoing fMRI scanning. RESULTS Compared with placebo, the aripiprazole group demonstrated enhanced DLPFC activation associated with a trend for improved discriminability (d') and speeded reaction times. In contrast to aripiprazole's neural effects, the risperidone group demonstrated a trend for reduced DLPFC recruitment. Unexpectedly, the risperidone group demonstrated similar effects to aripiprazole on d' and additionally had reduced errors of commission compared with placebo. CONCLUSION Aripiprazole has unique DLPFC actions attributed to its prefrontal D2 agonist action. Risperidone's serotinergic action that results in prefrontal dopamine release may have protected against any impairing effects of its prefrontal D2 blockade.
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Trantham-Davidson H, Chandler LJ. Alcohol-induced alterations in dopamine modulation of prefrontal activity. Alcohol 2015; 49:773-9. [PMID: 26558348 DOI: 10.1016/j.alcohol.2015.09.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 09/01/2015] [Accepted: 09/01/2015] [Indexed: 02/06/2023]
Abstract
Long-term alcohol use leads to persistent cognitive deficits that may be associated with maladaptive changes in the neurocircuitry that mediates executive functions. Impairments caused by these changes can persist well into abstinence and have a negative impact on quality of life and job performance, and can increase the probability of relapse. Many of the changes that affect cognitive function appear to involve dysregulation of the mesocortical dopamine system. This includes changes in dopamine release and alterations in dopamine receptor expression and function in the medial prefrontal cortex (PFC). This review summarizes the cellular effects of acute and chronic ethanol exposure on dopamine release and dopamine receptor function in the PFC with the goal of providing greater understanding of the effects of alcohol-use disorders on the dopamine system and how this relates to deficits in the executive function of the PFC.
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Affiliation(s)
| | - L Judson Chandler
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
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Allen RJ, Schaefer A, Falcon T. Recollecting positive and negative autobiographical memories disrupts working memory. Acta Psychol (Amst) 2014; 151:237-43. [PMID: 25086225 DOI: 10.1016/j.actpsy.2014.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 06/30/2014] [Accepted: 07/11/2014] [Indexed: 10/25/2022] Open
Abstract
The present article reports two experiments examining the impact of recollecting emotionally valenced autobiographical memories on subsequent working memory (WM) task performance. Experiment 1 found that negatively valenced recollection significantly disrupted performance on a supra-span spatial WM task. Experiment 2 replicated and extended these findings to a verbal WM task (digit recall), and found that both negative and positive autobiographical recollections had a detrimental effect on verbal WM. In addition, we observed that these disruptive effects were more apparent on early trials, immediately following autobiographical recollection. Overall, these findings show that both positive and negative affect can disrupt WM when the mood-eliciting context is based on autobiographical memories. Furthermore, these results indicate that the emotional disruption of WM can take place across different modalities of WM (verbal and visuo-spatial).
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Machielsen MW, Veltman DJ, van den Brink W, de Haan L. The effect of clozapine and risperidone on attentional bias in patients with schizophrenia and a cannabis use disorder: An fMRI study. J Psychopharmacol 2014; 28:633-42. [PMID: 24646809 DOI: 10.1177/0269881114527357] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cannabis use disorders (CUDs) are highly comorbid in patients with schizophrenia and are associated with poor outcome. Clozapine has been put forward as the first choice antipsychotic in this comorbid group. However, little is known about the mechanisms underlying the assumed superiority of clozapine. We compared the effects of clozapine and risperidone on attentional bias, subjective craving and associated regional brain activity in patients with schizophrenia and CUD. Overall, 36 patients with schizophrenia and 19 healthy controls were included. Patients were randomised to antipsychotic treatment with clozapine or risperidone. At baseline and after 4 weeks of medication use, regional brain responses were measured during a classical Stroop and a cannabis word Stroop using functional magnetic resonance imaging. Clozapine-treated CUD patients showed a larger reduction in craving and in activation of the insula during the cannabis word Stroop, while risperidone-treated patients showed a larger decrease in activation of the right anterior cingulate cortex during the classical Stroop. A significant association was found between decreases in subjective craving and decreases in insula activation during the cannabis word Stroop. These findings strongly suggest that clozapine may be a better treatment choice in patients with schizophrenia and CUD than risperidone.
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Affiliation(s)
| | - Dick J Veltman
- Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
| | - Wim van den Brink
- Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands
| | - Lieuwe de Haan
- Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands
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van Velzen LS, Vriend C, de Wit SJ, van den Heuvel OA. Response inhibition and interference control in obsessive-compulsive spectrum disorders. Front Hum Neurosci 2014; 8:419. [PMID: 24966828 PMCID: PMC4052433 DOI: 10.3389/fnhum.2014.00419] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 05/24/2014] [Indexed: 12/30/2022] Open
Abstract
Over the past 20 years, motor response inhibition and interference control have received considerable scientific effort and attention, due to their important role in behavior and the development of neuropsychiatric disorders. Results of neuroimaging studies indicate that motor response inhibition and interference control are dependent on cortical–striatal–thalamic–cortical (CSTC) circuits. Structural and functional abnormalities within the CSTC circuits have been reported for many neuropsychiatric disorders, including obsessive–compulsive disorder (OCD) and related disorders, such as attention-deficit hyperactivity disorder, Tourette’s syndrome, and trichotillomania. These disorders also share impairments in motor response inhibition and interference control, which may underlie some of their behavioral and cognitive symptoms. Results of task-related neuroimaging studies on inhibitory functions in these disorders show that impaired task performance is related to altered recruitment of the CSTC circuits. Previous research has shown that inhibitory performance is dependent upon dopamine, noradrenaline, and serotonin signaling, neurotransmitters that have been implicated in the pathophysiology of these disorders. In this narrative review, we discuss the common and disorder-specific pathophysiological mechanisms of inhibition-related dysfunction in OCD and related disorders.
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Affiliation(s)
- Laura S van Velzen
- GGZ InGeest , Amsterdam , Netherlands ; Neuroscience Campus Amsterdam (NCA) , Amsterdam , Netherlands
| | - Chris Vriend
- GGZ InGeest , Amsterdam , Netherlands ; Neuroscience Campus Amsterdam (NCA) , Amsterdam , Netherlands ; Department of Psychiatry, VU University Medical Center , Amsterdam , Netherlands ; Department of Anatomy and Neurosciences, VU University Medical Center , Amsterdam , Netherlands
| | - Stella J de Wit
- GGZ InGeest , Amsterdam , Netherlands ; Neuroscience Campus Amsterdam (NCA) , Amsterdam , Netherlands ; Department of Psychiatry, VU University Medical Center , Amsterdam , Netherlands
| | - Odile A van den Heuvel
- Neuroscience Campus Amsterdam (NCA) , Amsterdam , Netherlands ; Department of Psychiatry, VU University Medical Center , Amsterdam , Netherlands ; Department of Anatomy and Neurosciences, VU University Medical Center , Amsterdam , Netherlands
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Abstract
Dopamine is an important regulator of cognition and behavior, but its precise influence on human brain processing remains unclear because of the lack of a reliable technique to study dopamine in the live human brain. In the recent years, a number of techniques have been developed to detect, map, and measure dopamine released during task performance. Most of these techniques are based on molecular imaging methods and have varying degrees of sensitivity. We developed a single-scan dynamic molecular imaging technique for the detection of dopamine released during task performance in the live human brain. This technique is extremely sensitive and has test-retest reliability. Using this technique, we detected dopamine released during the processing of a number of cognitive, behavioral, and emotional tasks. Since this technique acquires data that cannot be obtained using any other techniques, it extends the scope of neuroimaging research.
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Moeller SJ, Honorio J, Tomasi D, Parvaz MA, Woicik PA, Volkow ND, Goldstein RZ. Methylphenidate enhances executive function and optimizes prefrontal function in both health and cocaine addiction. ACTA ACUST UNITED AC 2012; 24:643-53. [PMID: 23162047 DOI: 10.1093/cercor/bhs345] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Previous studies have suggested dopamine to be involved in error monitoring/processing, possibly through impact on reinforcement learning. The current study tested whether methylphenidate (MPH), an indirect dopamine agonist, modulates brain and behavioral responses to error, and whether such modulation is more pronounced in cocaine-addicted individuals, in whom dopamine neurotransmission is disrupted. After receiving oral MPH (20 mg) or placebo (counterbalanced), 15 healthy human volunteers and 16 cocaine-addicted individuals completed a task of executive function (the Stroop color word) during functional magnetic resonance imaging (fMRI). During MPH, despite not showing differences on percent accuracy and reaction time, all subjects committed fewer total errors and slowed down more after committing errors, suggestive of more careful responding. In parallel, during MPH all subjects showed reduced dorsal anterior cingulate cortex response to the fMRI contrast error>correct. In the cocaine subjects only, MPH also reduced error>correct activity in the dorsolateral prefrontal cortex (controls instead showed lower error>correct response in this region during placebo). Taken together, MPH modulated dopaminergically innervated prefrontal cortical areas involved in error-related processing, and such modulation was accentuated in the cocaine subjects. These results are consistent with a dopaminergic contribution to error-related processing during a cognitive control task.
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Abstract
Pharmacological cognitive enhancers (PCEs) are used to improve cognitive functions, such as attention, learning, memory and planning in patients with impairments in cognition resulting from traumatic brain injury (TBI) or from neuropsychiatric disorders such as Alzheimer's disease (AD), mild cognitive impairment, schizophrenia, and attention deficit hyperactivity disorder (ADHD). Moreover, PCEs have been shown to improve cognition in healthy volunteers with no psychiatric disorders. This article describes the rationale behind the need for their use in neuropsychiatric patients and illustrates how PCEs can ameliorate cognitive impairments, improve quality of life and wellbeing, and therefore reduce the economic burden associated with these disorders. We also describe evidence that PCEs are being used as cognitive enhancers by healthy people. Crucially, as the lifestyle use of these drugs becomes very popular in the healthy population, a final aim is to present an overview of the current and future neuroethical considerations of enhancing the healthy brain. As information regarding their actual use, benefits and harms in various healthy populations is currently lacking, we propose research that aims to obtain relevant empirical data, monitor the short- and long-term effectiveness and side-effects, and initiate accurate surveys to determine current patterns and quantity of usage of PCE drugs by healthy people. Furthermore, in order to instigate a dialogue between neuroethics and neuropsychopharmacology, we urge scientists to explore and communicate the social and ethical implications of their research to the public. Finally, we discuss and highlight other means of enhancing cognition in both patients and healthy adults, including education and physical exercise.
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Kwak Y, Müller ML, Bohnen NI, Dayalu P, Seidler RD. l-DOPA changes ventral striatum recruitment during motor sequence learning in Parkinson's disease. Behav Brain Res 2012; 230:116-24. [DOI: 10.1016/j.bbr.2012.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 01/28/2012] [Accepted: 02/02/2012] [Indexed: 10/14/2022]
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Liggins J, Pihl RO, Benkelfat C, Leyton M. The dopamine augmenter L-DOPA does not affect positive mood in healthy human volunteers. PLoS One 2012; 7:e28370. [PMID: 22238577 PMCID: PMC3251561 DOI: 10.1371/journal.pone.0028370] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 11/07/2011] [Indexed: 11/25/2022] Open
Abstract
Dopamine neurotransmission influences approach toward rewards and reward-related cues. The best cited interpretation of this effect proposes that dopamine mediates the pleasure that commonly accompanies reward. This hypothesis has received support in some animal models and a few studies in humans. However, direct assessments of the effect of transiently increasing dopamine neurotransmission have been largely limited to the use of psychostimulant drugs, which elevate brain levels of multiple neurotransmitters in addition to dopamine. In the present study we tested the effect of more selectively elevating dopamine neurotransmission, as produced by administration of the immediate dopamine precursor, L-DOPA (0, 100/25, 200/50 mg, Sinemet), in healthy human volunteers. Neither dose altered positive mood. The results suggest that dopamine neurotransmission does not directly influence positive mood in humans.
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Affiliation(s)
- John Liggins
- Department of Psychiatry, McGill University, Montréal, Québec, Canada
| | - Robert O. Pihl
- Department of Psychiatry, McGill University, Montréal, Québec, Canada
| | - Chawki Benkelfat
- Department of Psychiatry, McGill University, Montréal, Québec, Canada
| | - Marco Leyton
- Department of Psychiatry, McGill University, Montréal, Québec, Canada
- * E-mail:
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Sundermann B, Pfleiderer B, Möller HE, Schwindt W, Weglage J, Lepsien J, Feldmann R. Tackling frontal lobe-related functions in PKU through functional brain imaging: a Stroop task in adult patients. J Inherit Metab Dis 2011; 34:711-21. [PMID: 21491106 DOI: 10.1007/s10545-011-9318-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 02/28/2011] [Accepted: 03/18/2011] [Indexed: 12/26/2022]
Abstract
BACKGROUND Profound mental retardation in phenylketonuria (PKU) can be prevented by a low phenylalanine (Phe) diet. However, even patients treated early have inconsistently shown deficits in several frontal lobe-related neuropsychological tasks such as the widely accepted Stroop task. The goal of this study was to investigate whether adult patients exhibit altered brain activation in Stroop-related locations in comparison to healthy controls and if an acute increase in blood Phe levels in patients has an effect on activation patterns. METHODS Seventeen male, early-treated patients with classic PKU (mean ± SD age: 31.0 ± 5.2 years) and 15 male healthy controls (32.1 ± 6.4 years) were compared using a color-word matching Stroop task in a functional magnetic resonance imaging (fMRI) study at 3T. Participants were scanned twice, and an oral Phe load (100 mg/kg body weight) was administered to patients prior to one of the fMRI sessions (placebo-controlled). Activity in brain regions that are known to be involved in Stroop tasks was assessed. RESULTS PKU patients exhibited poorer accuracy in incongruent trials. Reaction times were not significantly different. There were no consistent differences in BOLD activations in Stroop-associated brain regions. The oral Phe administration had no significant effect on brain activity. CONCLUSIONS Neither a generally slower task performance nor distinctively altered functioning of brain networks involved in a task representing a subset of dopamine-dependent executive functions could be proven. Decreased accuracy and inconsistent findings in posterior areas necessitate further study of frontal-lobe functioning in PKU patients in larger study samples.
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Affiliation(s)
- Benedikt Sundermann
- Department of Clinical Radiology, University Hospital Muenster, Albert-Schweitzer-Str. 33, 48149 Muenster, Germany
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Lesh TA, Niendam TA, Minzenberg MJ, Carter CS. Cognitive control deficits in schizophrenia: mechanisms and meaning. Neuropsychopharmacology 2011; 36:316-38. [PMID: 20844478 PMCID: PMC3052853 DOI: 10.1038/npp.2010.156] [Citation(s) in RCA: 358] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 08/11/2010] [Accepted: 08/11/2010] [Indexed: 12/27/2022]
Abstract
Although schizophrenia is an illness that has been historically characterized by the presence of positive symptomatology, decades of research highlight the importance of cognitive deficits in this disorder. This review proposes that the theoretical model of cognitive control, which is based on contemporary cognitive neuroscience, provides a unifying theory for the cognitive and neural abnormalities underlying higher cognitive dysfunction in schizophrenia. To support this model, we outline converging evidence from multiple modalities (eg, structural and functional neuroimaging, pharmacological data, and animal models) and samples (eg, clinical high risk, genetic high risk, first episode, and chronic subjects) to emphasize how dysfunction in cognitive control mechanisms supported by the prefrontal cortex contribute to the pathophysiology of higher cognitive deficits in schizophrenia. Our model provides a theoretical link between cellular abnormalities (eg, reductions in dentritic spines, interneuronal dysfunction), functional disturbances in local circuit function (eg, gamma abnormalities), altered inter-regional cortical connectivity, a range of higher cognitive deficits, and symptom presentation (eg, disorganization) in the disorder. Finally, we discuss recent advances in the neuropharmacology of cognition and how they can inform a targeted approach to the development of effective therapies for this disabling aspect of schizophrenia.
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Affiliation(s)
- Tyler A Lesh
- Department of Psychiatry, UC Davis Imaging Research Center, Davis School of Medicine, University of California, Sacramento, CA, USA
| | - Tara A Niendam
- Department of Psychiatry, UC Davis Imaging Research Center, Davis School of Medicine, University of California, Sacramento, CA, USA
| | - Michael J Minzenberg
- Department of Psychiatry, UC Davis Imaging Research Center, Davis School of Medicine, University of California, Sacramento, CA, USA
| | - Cameron S Carter
- Department of Psychiatry, UC Davis Imaging Research Center, Davis School of Medicine, University of California, Sacramento, CA, USA
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Frank MJ, Fossella JA. Neurogenetics and pharmacology of learning, motivation, and cognition. Neuropsychopharmacology 2011; 36:133-52. [PMID: 20631684 PMCID: PMC3055524 DOI: 10.1038/npp.2010.96] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 06/09/2010] [Accepted: 06/10/2010] [Indexed: 02/07/2023]
Abstract
Many of the individual differences in cognition, motivation, and learning-and the disruption of these processes in neurological conditions-are influenced by genetic factors. We provide an integrative synthesis across human and animal studies, focusing on a recent spate of evidence implicating a role for genes controlling dopaminergic function in frontostriatal circuitry, including COMT, DARPP-32, DAT1, DRD2, and DRD4. These genetic effects are interpreted within theoretical frameworks developed in the context of the broader cognitive and computational neuroscience literature, constrained by data from pharmacological, neuroimaging, electrophysiological, and patient studies. In this framework, genes modulate the efficacy of particular neural computations, and effects of genetic variation are revealed by assays designed to be maximally sensitive to these computations. We discuss the merits and caveats of this approach and outline a number of novel candidate genes of interest for future study.
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Affiliation(s)
- Michael J Frank
- Department of Cognitive, Linguistic and Psychological Sciences, Brown Institute for Brain Science, Brown University, Providence, RI 02912-1978, USA.
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21
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Allman AA, Benkelfat C, Durand F, Sibon I, Dagher A, Leyton M, Baker GB, O'Driscoll GA. Effect of D-amphetamine on inhibition and motor planning as a function of baseline performance. Psychopharmacology (Berl) 2010; 211:423-33. [PMID: 20602089 DOI: 10.1007/s00213-010-1912-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 06/04/2010] [Indexed: 12/23/2022]
Abstract
RATIONALE Baseline performance has been reported to predict dopamine (DA) effects on working memory, following an inverted-U pattern. This pattern may hold true for other executive functions that are DA-sensitive. OBJECTIVES The objective of this study is to investigate the effect of D: -amphetamine, an indirect DA agonist, on two other putatively DA-sensitive executive functions, inhibition and motor planning, as a function of baseline performance. METHODS Participants with no prior stimulant exposure participated in a double-blind crossover study of a single dose of 0.3 mg/kg, p.o. of D: -amphetamine and placebo. Participants were divided into high and low groups, based on their performance on the antisaccade and predictive saccade tasks on the baseline day. Executive functions, mood states, heart rate and blood pressure were assessed before (T0) and after drug administration, at 1.5 (T1), 2.5 (T2) and 3.5 h (T3) post-drug. RESULTS Antisaccade errors decreased with D: -amphetamine irrespective of baseline performance (p = 0.025). For antisaccade latency, participants who generated short-latency antisaccades at baseline had longer latencies on D: -amphetamine than placebo, while those with long-latency antisaccades at baseline had shorter latencies on D: -amphetamine than placebo (drug x group, p = 0.04). D: -amphetamine did not affect motor planning. Ratings of mood improved on D: -amphetamine (p < 0.001). Magnitude of D: -amphetamine-induced changes in elation was related to baseline reaction time variability. CONCLUSIONS D: -amphetamine reduced antisaccade error rates in healthy controls, replicating and extending findings with DA agonists in clinical populations. D: -amphetamine had baseline-dependent effects on antisaccade latency, consistent with an inverted-U relationship between performance and DA activity.
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Affiliation(s)
- Ava-Ann Allman
- Department of Psychology, McGill University, 1205 Dr. Penfield Avenue, Montreal, QC, H3A 1B1, Canada
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Egerton A, Mehta MA, Montgomery AJ, Lappin JM, Howes OD, Reeves SJ, Cunningham VJ, Grasby PM. The dopaminergic basis of human behaviors: A review of molecular imaging studies. Neurosci Biobehav Rev 2009; 33:1109-32. [PMID: 19481108 DOI: 10.1016/j.neubiorev.2009.05.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 05/14/2009] [Accepted: 05/18/2009] [Indexed: 11/16/2022]
Abstract
This systematic review describes human molecular imaging studies which have investigated alterations in extracellular DA levels during performance of behavioral tasks. Whilst heterogeneity in experimental methods limits meta-analysis, we describe the advantages and limitations of different methodological approaches. Interpretation of experimental results may be limited by regional cerebral blood flow (rCBF) changes, head movement and choice of control conditions. We revisit our original study of striatal DA release during video-game playing [Koepp, M.J., Gunn, R.N., Lawrence, A.D., Cunningham, V.J., Dagher, A., Jones, T., Brooks, D.J., Bench, C.J., Grasby, P.M., 1998. Evidence for striatal dopamine release during a video game. Nature 393, 266-268] to illustrate the potentially confounding influences of head movement and alterations in rCBF. Changes in [(11)C]raclopride binding may be detected in extrastriatal as well as striatal brain regions-however we review evidence which suggests that extrastriatal changes may not be clearly interpreted in terms of DA release. Whilst several investigations have detected increases in striatal extracellular DA concentrations during task components such as motor learning and execution, reward-related processes, stress and cognitive performance, the presence of potentially biasing factors should be carefully considered (and, where possible, accounted for) when designing and interpreting future studies.
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Affiliation(s)
- Alice Egerton
- Medical Research Council Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, United Kingdom.
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Raz N, Rodrigue KM, Kennedy KM, Land S. Genetic and vascular modifiers of age-sensitive cognitive skills: effects of COMT, BDNF, ApoE, and hypertension. Neuropsychology 2009; 23:105-116. [PMID: 19210038 DOI: 10.1037/a0013487] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Several single nucleotide polymorphisms have been linked to neural and cognitive variation in healthy adults. We examined contribution of three polymorphisms frequently associated with individual differences in cognition (Catechol-O-Methyl-Transferase Val158Met, Brain-Derived-Neurotrophic-Factor Val66Met, and Apolipoprotein E epsilon4) and a vascular risk factor (hypertension) in a sample of 189 volunteers (age 18-82). Genotypes were determined from buccal culture samples, and cognitive performance was assessed in 4 age-sensitive domains?fluid intelligence, executive function (inhibition), associative memory, and processing speed. We found that younger age and COMT Met/Met genotype, associated with low COMT activity and higher prefrontal dopamine content, were independently linked to better performance in most of the tested domains. Homozygotes for Val allele of BDNF polymorphism exhibited better associative memory and faster speed of processing than the Met allele carriers, with greater effect for women and persons with hypertension. Carriers of ApoE epsilon4 allele evidenced steeper age-related increase in costs of Stroop color interference, but showed no negative effects on memory. The findings indicate that age-related cognitive performance is differentially affected by distinct genetic factors and their interactions with vascular health status.
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Abstract
Past research has demonstrated that performance on frontal lobe-dependent tasks is associated with dopamine system integrity and that various dopamine system deficits occur with aging. The positron emission tomography (PET) radiotracer 6-[(18)F]fluoro-l-m-tyrosine (FMT) is a substrate of the dopamine-synthesizing enzyme, aromatic amino acid decarboxylase (AADC). Studies using 6-[(18)F]fluorodopa (FDOPA) (another AADC substrate) to measure how striatal PET signal and age relate have had inconsistent outcomes. The varying results occur in part from tracer processing that renders FDOPA signal subject to aspects of postrelease metabolism, which may themselves change with aging. In contrast, FMT remains a purer measure of AADC function. We used partial volume-corrected FMT PET scans to measure age-related striatal dopamine synthesis capacity in 21 older (mean, 66.9) and 16 younger (mean, 22.8) healthy adults. We also investigated how striatal FMT signal related to a cognitive measure of frontal lobe function. Older adults showed significantly greater striatal FMT signal than younger adults. Within the older group, FMT signal in dorsal caudate (DCA) and dorsal putamen was greater with age, suggesting compensation for deficits elsewhere in the dopamine system. In younger adults, FMT signal in DCA was lower with age, likely related to ongoing developmental processes. Younger adults who performed worse on tests of frontal lobe function showed greater FMT signal in right DCA, independent of age effects. Our data suggest that higher striatal FMT signal represents nonoptimal dopamine processing. They further support a relationship between striatal dopamine processing and frontal lobe cognitive function.
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Wiebe SA, Espy KA, Stopp C, Respass J, Stewart P, Jameson TR, Gilbert DG, Huggenvik JI. Gene-environment interactions across development: Exploring DRD2 genotype and prenatal smoking effects on self-regulation. Dev Psychol 2009; 45:31-44. [PMID: 19209988 PMCID: PMC2855236 DOI: 10.1037/a0014550] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Genetic factors dynamically interact with both pre- and postnatal environmental influences to shape development. Considerable attention has been devoted to gene-environment interactions (G x E) on important outcomes (A. Caspi & T. E. Moffitt, 2006). It is also important to consider the possibility that these G x E effects may vary across development, particularly for constructs like self-regulation that emerge slowly, depend on brain regions that change qualitatively in different developmental periods, and thus may be manifested differently. To illustrate one approach to exploring such developmental patterns, the relation between variation in the TaqIA polymorphism, related to D2 dopamine receptor expression and availability, and prenatal exposure to tobacco was examined in two exploratory studies. First, in 4-week-old neonates, genotype-exposure interactions were observed for attention and irritable reactivity, but not for stress dysregulation. Second, in preschool children, genotype was related to Preschool Trail Making Test (K. A. Espy and M. F. Cwik, 2004) task performance on conditions requiring executive control; children with both the A1+ genotype and a history of prenatal tobacco exposure displayed disproportionately poor performance. Despite study limitations, these results illustrate the importance of examining the interplay between genetic and prenatal environmental factors across development.
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Affiliation(s)
- Sandra A Wiebe
- Department of Psychology, University of Nebraska-Lincoln, USA.
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27
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Imaging the genetics of executive function. Biol Psychol 2008; 79:30-42. [DOI: 10.1016/j.biopsycho.2007.11.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 11/22/2007] [Accepted: 11/23/2007] [Indexed: 01/27/2023]
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Snyder AM, Maruff P, Pietrzak RH, Cromer JR, Snyder PJ. Effect of Treatment with Stimulant Medication on Nonverbal Executive Function and Visuomotor Speed in Children with Attention Deficit/Hyperactivity Disorder (ADHD). Child Neuropsychol 2008; 14:211-26. [PMID: 17852127 DOI: 10.1080/09297040701220005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study used a novel hidden maze learning test to examine the nature and magnitude of impairment on separable aspects of executive function in 36 children with ADHD. A within-subject analysis of children with ADHD was also conducted to assess cognitive effects of open-label stimulant treatment. Compared to 31 age-matched controls, unmedicated children with ADHD were slower and made significantly more errors that were indicative of relative impairment in prepotent response inhibition and ability to "maintain set" while using simple rules to complete the task. Open-label administration of stimulant medication led to faster and more efficient performance, with children with ADHD making fewer perseverative and rule-break errors than when off medication. This instrument might be useful in monitoring treatment response in specific aspects of executive function and in assisting with dose-titration decisions.
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Affiliation(s)
- Andrew M Snyder
- Department of Pediatrics, Hasbro Children's Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, USA.
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Ellis KA, Mehta MA, Naga Venkatesha Murthy P, McTavish SF, Nathan PJ, Grasby PM. Tyrosine depletion alters cortical and limbic blood flow but does not modulate spatial working memory performance or task-related blood flow in humans. Hum Brain Mapp 2008; 28:1136-49. [PMID: 17290373 PMCID: PMC6871381 DOI: 10.1002/hbm.20339] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dopamine appears critical in regulating spatial working memory (SWM) within the PFC of non-human primates; however findings in humans are less clear. Recent studies of the effects of global depletion of dopamine via acute tyrosine/phenylalanine depletion (TPD) on SWM task performance have yielded inconsistent results, which may be partly related to task differences. These previous studies do not address whether TPD can directly impair PFC functioning. The current study investigated the effects of TPD on (1) regional cerebral blood flow (rCBF) during a SWM n-back task using H(2) (15)O Positron Emission Tomography (PET), and (2) behavioural performance on three different SWM tasks. Ten healthy males were scanned twice: once following a placebo (balanced) amino acid mixture and once following an equivalent mixture deficient in tyrosine/phenylalanine (TPD condition). Participants completed two additional delayed-response tasks to examine whether differences in response demands influenced TPD effects on performance. TPD resulted in widespread increases in rCBF, with maximum increases in the region of the parahippocampal gyrus bilaterally, left inferior frontal gyrus, and the putamen. TPD related rCBF reductions were observed in the medial frontal gyrus bilaterally, right inferior temporal gyrus and the pons. Despite widespread changes in blood flow following TPD, no specific effects on SWM neural networks or task performance were observed. The use of three different SWM tasks suggests that task differences are unlikely to account for the lack of effects observed. These findings question the capacity of TPD to consistently modulate dopamine function and SWM neural networks in humans.
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Affiliation(s)
- Kathryn A. Ellis
- Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia
- Academic Unit for Psychiatry of Old Age, Department of Psychiatry, University of Melbourne, Melbourne, Australia
| | - Mitul A. Mehta
- PET Psychiatry, Medical Research Council Clinical Sciences Centre (of the Faculty of Medicine, Imperial College London), Hammersmith Hospital, London, United Kingdom
- Division of Neuroscience and Psychological Medicine (of the Faculty of Medicine, Imperial College London), Hammersmith Hospital, London, United Kingdom
- Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College, London, United Kingdom
| | - P.J. Naga Venkatesha Murthy
- PET Psychiatry, Medical Research Council Clinical Sciences Centre (of the Faculty of Medicine, Imperial College London), Hammersmith Hospital, London, United Kingdom
- Division of Neuroscience and Psychological Medicine (of the Faculty of Medicine, Imperial College London), Hammersmith Hospital, London, United Kingdom
| | - Sarah F.B. McTavish
- Department of Psychiatry (of the University of Oxford), Warneford Hospital, Oxford, United Kingdom
| | - Pradeep J. Nathan
- School of Psychology, Psychiatry and Psychological Medicine (SPPPM), Monash University, Melbourne, Australia
| | - Paul M. Grasby
- PET Psychiatry, Medical Research Council Clinical Sciences Centre (of the Faculty of Medicine, Imperial College London), Hammersmith Hospital, London, United Kingdom
- Division of Neuroscience and Psychological Medicine (of the Faculty of Medicine, Imperial College London), Hammersmith Hospital, London, United Kingdom
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de Jongh R, Bolt I, Schermer M, Olivier B. Botox for the brain: enhancement of cognition, mood and pro-social behavior and blunting of unwanted memories. Neurosci Biobehav Rev 2008; 32:760-76. [DOI: 10.1016/j.neubiorev.2007.12.001] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 10/15/2007] [Accepted: 12/17/2007] [Indexed: 11/25/2022]
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Scholes KE, Harrison BJ, O'Neill BV, Leung S, Croft RJ, Pipingas A, Phan KL, Nathan PJ. Acute serotonin and dopamine depletion improves attentional control: findings from the stroop task. Neuropsychopharmacology 2007; 32:1600-10. [PMID: 17151596 DOI: 10.1038/sj.npp.1301262] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Schizophrenia is associated with impairments of attentional control on classic experimental paradigms such as the Stroop task. However, at a basic level the neurochemical mechanisms that may be responsible for such impairments are poorly understood. In this study, we sought to investigate the influence of brain monoamine function on Stroop task performance in healthy participants using the established methods of acute dietary serotonin, dopamine, and combined monoamine depletion. The study was a double-blind placebo controlled design in which 12 healthy male participants completed the Stroop task under four acute treatment conditions: (a) balanced/placebo control, (b) acute tryptophan depletion, (c) acute tyrosine/phenylalanine depletion, and (d) acute tyrosine/phenylalanine/tryptophan depletion (combined monoamine depletion). Decreased Stroop interference indicating improved attentional control was observed after both tryptophan depletion and tyrosine/phenylalanine depletion, while there was no significant change in interference after combined monoamine depletion. Findings suggest that reduced tonic dopamine or serotonin activity within specific neural circuits (such as the striatum, anterior cingulate, or prefrontal cortex) may play a critical role in attentional control, possibly by improving gating of information via reducing noise in monoaminergic systems. These findings enhance our understanding of the neurochemical basis of attentional control and the possible cause of attentional control deficits in schizophrenia.
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Affiliation(s)
- Kirsty E Scholes
- Behavioural Neuroscience Laboratory, Department of Physiology, Monash Centre for Brain and Behavior, Monash University, Melbourne, VIC, Australia
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Samuels ER, Hou RH, Langley RW, Szabadi E, Bradshaw CM. Comparison of pramipexole with and without domperidone co-administration on alertness, autonomic, and endocrine functions in healthy volunteers. Br J Clin Pharmacol 2007; 64:591-602. [PMID: 17578485 PMCID: PMC2203276 DOI: 10.1111/j.1365-2125.2007.02938.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS To investigate the effects of the D2-receptor agonist pramipexole with and without the co-administration of the peripherally acting D2-receptor antagonist domperidone on measures of alertness, autonomic and endocrine function. METHODS Sixteen male volunteers participated in four weekly sessions of pramipexole 0.5 mg, domperidone 40 mg, their combination, and placebo administered according to a balanced, double-blind design. Alertness (visual analogue scales (VAS), critical flicker fusion frequency, pupillographic sleepiness test), autonomic (pupil diameter, light and darkness reflexes, blood pressure, heart rate, salivation, temperature) and endocrine (prolactin, thyroid-stimulating hormone (TSH), growth hormone (GH)) functions were assessed. Data were analyzed with anova with multiple comparisons. RESULTS The pre-post treatment changes in VAS alertness were reduced by pramipexole with and without domperidone (mean difference from placebo (95% confidence interval), mm): pramipexole -15.75 (-23.38, -8.13), combination -11.84 (-20.77, -2.91). Treatment condition significantly affected pupil diameter measured in different ways (resting pupil diameter (F(3,45) = 8.39, P < 0.001), initial diameter of the light reflex response (F(3,42) = 3.78, P < 0.05), and light (F(3,45) = 5.21, P < 0.005) and dark (F(3,45) = 3.36, P < 0.05) diameters of the darkness reflex response). Pramipexole without domperidone consistently increased pupil diameter on all measures (P < 0.05), whereas with domperidone only the increase in resting and dark diameters reached significance. Pramipexole reduced light reflex amplitude and increased latency, whereas the combination affected latency only. Concentrations of prolactin and TSH were increased by domperidone. Pramipexole reduced prolactin and increased GH concentrations. CONCLUSIONS The attenuation of the central pupillary effects of pramipexole by domperidone indicates that domperidone had access to some central D2-receptors.
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Affiliation(s)
- Ebony R Samuels
- Psychopharmacology Section, University of Nottingham, Division of Psychiatry, Nottingham, UK
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Breitenstein C, Korsukewitz C, Flöel A, Kretzschmar T, Diederich K, Knecht S. Tonic dopaminergic stimulation impairs associative learning in healthy subjects. Neuropsychopharmacology 2006; 31:2552-64. [PMID: 16880771 DOI: 10.1038/sj.npp.1301167] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Endogenous dopamine plays a central role in salience coding during associative learning. Administration of the dopamine precursor levodopa enhances learning in healthy subjects and stroke patients. Because levodopa increases both phasic and tonic dopaminergic neurotransmission, the critical mechanism mediating the enhancement of learning is unresolved. We here probed how selective tonic dopaminergic stimulation affects associative learning. Forty healthy subjects were trained in a novel vocabulary of 45 concrete nouns over the course of 5 consecutive training days in a prospective, randomized, double-blind, placebo-controlled design. Subjects received the tonically stimulating dopamine-receptor agonist pergolide (0.1 mg) vs placebo 120 min before training on each training day. The dopamine agonist significantly impaired novel word learning compared to placebo. This learning decrement persisted up to the last follow-up 4 weeks post-training. Subjects treated with pergolide also showed restricted emotional responses compared to the PLACEBO group. The extent of 'flattened' affect with pergolide was related to the degree of learning inhibition. These findings suggest that tonic occupation of dopamine receptors impairs learning by competition with phasic dopamine signals. Thus, phasic signaling seems to be the critical mechanism by which dopamine enhances associative learning in healthy subjects and stroke patients.
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Lovallo WR, Yechiam E, Sorocco KH, Vincent AS, Collins FL. Working memory and decision-making biases in young adults with a family history of alcoholism: studies from the Oklahoma family health patterns project. Alcohol Clin Exp Res 2006; 30:763-73. [PMID: 16634844 PMCID: PMC2257923 DOI: 10.1111/j.1530-0277.2006.00089.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Alcohol misuse is more common in persons with a family history of alcoholism (FH+) than in those with no such history (FH-). Among FH+, behavioral disinhibition and male sex seem to signal the presence of an increased risk. METHODS This study examined cognitive and behavioral characteristics of 175 nonabusing 18- to 30-year-olds, 87 FH+ and 88 FH-, who were further characterized by their degree of behavioral disinhibition using the Sociability scale of the California Personality Inventory. Working memory and decision making were tested using the Stroop Color-Word Test and the Iowa Gambling Task, a simulated card game. RESULTS Persons with a family history of alcoholism who were behaviorally disinhibited displayed significantly greater interference on the Stroop task than the other subgroups. On the Iowa Gambling Task, FH+ males, but not the females, were significantly more attentive to financial gains than other subgroups, and they had greater consistency in their choice behaviors. CONCLUSIONS Persons with a family history of alcoholism, in combination with behavioral disinhibition, appears to signal working memory deficits and in combination with male sex indicates an attraction to the rewarding aspects of a risk-taking challenge. These findings are not secondary to heavy exposure to alcohol or other drugs, but instead reflect intrinsic risk-related familial and personal characteristics of the subjects.
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Affiliation(s)
- William R Lovallo
- Behavioral Sciences Laboratories, Veterans Affairs Medical Center, and Department of Psychiatry and Behavioral Sciences, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA.
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Roesch-Ely D, Weiland S, Scheffel H, Schwaninger M, Hundemer HP, Kolter T, Weisbrod M. Dopaminergic modulation of semantic priming in healthy volunteers. Biol Psychiatry 2006; 60:604-11. [PMID: 16603132 DOI: 10.1016/j.biopsych.2006.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Revised: 01/17/2006] [Accepted: 01/19/2006] [Indexed: 12/21/2022]
Abstract
BACKGROUND Semantic priming is a function related to prefrontal cortical (PFC) networks and is lateralized. There is evidence that semantic priming underlies dopaminergic modulation. It is known that the D1-receptor is more abundant in prefrontal networks; however, until now there have been no studies investigating the selective modulation of semantic priming with dopamine agonists. Furthermore, D1 receptor dysfunction has been described in schizophrenia, and patients with formal thought disorder seem to have disturbed focusing of associations and increased indirect priming. METHODS With a subtraction design, we compared the influence of pergolide (D1/D2 agonist) with bromocriptine (D2 agonist) and placebo, in a randomized, double-blind, crossover design in 40 healthy male volunteers. Subjects performed a lateralized lexical decision task including direct and indirect related prime-target pairs (stimulus onset asynchrony = 750 msec). RESULTS Only on pergolide a decrease of the indirect priming in the left hemisphere presentations was found. CONCLUSIONS These findings point to a potential selective modulation of agonists with a D1 component on the focusing of semantic associations. The clinical relevance of this study is that it might help the development of therapeutic strategies for treating cognitive deficits in schizophrenia and Parkinson's disease, which are highly relevant to the functional outcome.
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Affiliation(s)
- Daniela Roesch-Ely
- Psychiatry Hospital, University of Heidelberg, Heidelberg, Bad Homburg, Germany.
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Cropley VL, Fujita M, Innis RB, Nathan PJ. Molecular imaging of the dopaminergic system and its association with human cognitive function. Biol Psychiatry 2006; 59:898-907. [PMID: 16682268 DOI: 10.1016/j.biopsych.2006.03.004] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 10/07/2005] [Accepted: 03/06/2006] [Indexed: 11/16/2022]
Abstract
Molecular imaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) has recently been used to examine dopamine (DA) function and its relationship with cognition in human subjects. This article will review PET and SPECT studies that have explored the relationship between cognitive processes and components of the DA system (pre-, intra-, and postsynaptic) in healthy and patient populations such as Parkinson's disease (PD), schizophrenia, Huntington's disease, and aging. It is demonstrated that DA activity modulates a range of frontal executive-type cognitive processes such as working memory, attentional functioning, and sequential organization, and alterations of DA within the fronto-striato-thalamic circuits might contribute to the cognitive impairments observed in PD, schizophrenia, and normal aging. Although associations between DA and cognitive measures need to be considered within the context of fronto-striato-thalamic circuitry, it is suggested that striatal (especially caudate) DA activity, particularly via D2 receptors, might be important for response inhibition, temporal organization of material, and motor performance, whereas cortical DA transmission via D1 receptors might be important for maintaining and representing on-going behavior.
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Affiliation(s)
- Vanessa L Cropley
- Department of Physiology, Behavioural Neuroscience Laboratory, Monash Centre for Brain and Behaviour, Monash University, Victoria, Australia.
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Tanaka S. Dopaminergic control of working memory and its relevance to schizophrenia: A circuit dynamics perspective. Neuroscience 2006; 139:153-71. [PMID: 16324800 DOI: 10.1016/j.neuroscience.2005.08.070] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 08/10/2005] [Accepted: 08/24/2005] [Indexed: 11/21/2022]
Abstract
This article argues how dopamine controls working memory and how the dysregulation of the dopaminergic system is related to schizophrenia. In the dorsolateral prefrontal cortex, which is the principal part of the working memory system, recurrent excitation is subtly balanced with intracortical inhibition. A potent controller of the dorsolateral prefrontal cortical circuit is the mesocortical dopaminergic system. To understand the characteristics of the dopaminergic control of working memory, the stability of the circuit dynamics under the influence of dopamine has been studied. Recent computational studies suggest that the hyperdopaminergic state is usually stable but the hypodopaminergic state tends to be unstable. The stability also depends on the efficacy of the glutamatergic transmission in the corticomesencephalic projections to dopamine neurons. When this cortical feedback is hypoglutamatergic, the circuit of the dorsolateral prefrontal cortex tends to be unstable, such that a slight increase in dopamine releasability causes a catastrophic jump of the dorsolateral prefrontal cortex activity from a low to a high level. This may account for the seemingly paradoxical overactivation of the dorsolateral prefrontal cortex observed in schizophrenic patients. Given that dopamine transmission is abnormal in the brains of patients with schizophrenia and working memory deficit is a core dysfunction in schizophrenia, the concept of circuit stability would be useful not only for understanding the mechanisms of working memory processing but for developing therapeutic strategies to enhance cognitive functions in schizophrenia.
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Affiliation(s)
- S Tanaka
- Department of Electrical and Electronics Engineering, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan.
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Frank MJ, O'Reilly RC. A mechanistic account of striatal dopamine function in human cognition: Psychopharmacological studies with cabergoline and haloperidol. Behav Neurosci 2006; 120:497-517. [PMID: 16768602 DOI: 10.1037/0735-7044.120.3.497] [Citation(s) in RCA: 320] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The authors test a neurocomputational model of dopamine function in cognition by administering to healthy participants low doses of D2 agents cabergoline and haloperidol. The model suggests that DA dynamically modulates the balance of Go and No-Go basal ganglia pathways during cognitive learning and performance. Cabergoline impaired, while haloperidol enhanced, Go learning from positive reinforcement, consistent with presynaptic drug effects. Cabergoline also caused an overall bias toward Go responding, consistent with postsynaptic action. These same effects extended to working memory and attentional domains, supporting the idea that the basal ganglia/dopamine system modulates the updating of prefrontal representations. Drug effects interacted with baseline working memory span in all tasks. Taken together, the results support a unified account of the role of dopamine in modulating cognitive processes that depend on the basal ganglia.
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Affiliation(s)
- Michael J Frank
- Department of Psychology and Program in NeuroscienceUniversity of Arizona, Tucson, AZ 85721, USA.
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Ellis KA, Mehta MA, Wesnes KA, Armstrong S, Nathan PJ. Combined D1/D2 receptor stimulation under conditions of dopamine depletion impairs spatial working memory performance in humans. Psychopharmacology (Berl) 2005; 181:771-80. [PMID: 15983794 DOI: 10.1007/s00213-005-0019-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Accepted: 03/31/2005] [Indexed: 10/25/2022]
Abstract
RATIONALE The mesocortical dopamine system is regarded as an important modulator of working memory. While it has been established that stimulation of the D1/D2 receptor in primates can improve spatial working memory performance, findings in humans are less consistent. Recent studies in humans suggest that global depletion of dopamine via tyrosine/phenylalanine depletion may impair spatial working memory performance, although these results are also inconsistent, and it has been suggested that task differences may partly underlie the inconsistent findings. OBJECTIVES This study had two aims: (1) to investigate the effects of acute tyrosine depletion (TPD) on a number of working memory tasks and (2) to examine whether stimulation of D1/D2 receptors under conditions of TPD can attenuate or "reverse" TPD-induced working memory impairments. METHODS Eighteen healthy male participants performed a spatial working memory delayed-recognition task, non-spatial working memory task and spatial n-back task on three separate occasions, after TPD, TPD and pergolide (D1/D2 agonist), and placebo. RESULTS TPD did not impair working memory performance on any of the tasks administered. However, stimulation of D1/D2 receptors under TPD conditions caused a subtle impairment in spatial working memory performance. CONCLUSIONS The finding that D1/D2 stimulation under TPD conditions impairs working memory highlights the complexity of functional effects of augmenting dopaminergic transmission within a dopamine-depleted state. The lack of TPD-related effects on a range of working memory tasks questions the reliability of TPD as a modulator of dopamine function and working memory performance in humans.
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Affiliation(s)
- Kathryn A Ellis
- Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia.
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Reeves SJ, Grasby PM, Howard RJ, Bantick RA, Asselin MC, Mehta MA. A positron emission tomography (PET) investigation of the role of striatal dopamine (D2) receptor availability in spatial cognition. Neuroimage 2005; 28:216-26. [PMID: 15979345 DOI: 10.1016/j.neuroimage.2005.05.034] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 04/26/2005] [Accepted: 05/19/2005] [Indexed: 10/25/2022] Open
Abstract
The functional significance of age-related changes in regional brain dopamine (DA) function is poorly understood in health. Two recent studies have reported positive linear associations between measures of striatal DA (D2) receptor availability (binding potential) and specific aspects of motor and cognitive performance, after controlling for the effects of age [(Volkow, N.D., Gur, R.C., Wang, G.-J., Fowler, J.S., Moberg, P.J., Ding, Y.-S., Hitzemann, R., Smith, G., Logan, J., 1998. Association between decline in brain dopamine activity with age and cognitive and motor impairment in healthy individuals. Am. J. Psychiatry 155 (3), 344-349; Backman, L., Ginovart, N., Dixon, R.A., Wahlin, T.-B.R., Wahlin, A., Halldin, C., Farde, L., 2000. Age-related cognitive deficits mediated by changes in the striatal dopamine system. Am. J. Psychiatry 157 (4), 635-637)]. We investigated the relationship between measures of striatal DA (D2) receptor availability and visuo-spatial cognitive performance in thirty healthy post-menopausal women aged 58-90 years. [(11)C] Raclopride (RAC) positron emission tomography (PET) was used to assess dopamine (D2) receptor availability. The CANTAB neuropsychological test battery was used to assess spatial span, spatial working memory (SWM) and planning ability. Age showed significant linear correlations with several of the CANTAB performance measures. After controlling for age effects, DA (D2) receptor measures in left-sided striatal regions (caudate and putamen) were significantly and positively correlated with 'perfect solution' scores--the measure of performance accuracy--on the Tower of London (TOL) test of spatial planning. When this relationship was examined in relation to task difficulty, only perfect scores for the most 'difficult' (4-move) problems were significantly correlated with BP measures in all striatal regions, most notably the right and left caudate nuclei. Paradoxically, individuals with higher DA (D2) receptor measures in the right caudate performed less accurately on the SWM task, exhibiting a higher number of errors within each search sequence. The relative contribution of striatal DA (D2) receptor availability to specific aspects of cognitive performance needs to be evaluated in larger mixed-sex samples to facilitate the meaningful investigation of the potential therapeutic benefits of DA (D2) agonists in later life.
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Affiliation(s)
- Suzanne J Reeves
- Section of Old Age Psychiatry, Institute of Psychiatry, De Crespigny Park, London, UK.
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