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Caprioli D, Hong YT, Sawiak SJ, Ferrari V, Williamson DJ, Jupp B, Adrian Carpenter T, Aigbirhio FI, Everitt BJ, Robbins TW, Fryer TD, Dalley JW. Baseline-dependent effects of cocaine pre-exposure on impulsivity and D2/3 receptor availability in the rat striatum: possible relevance to the attention-deficit hyperactivity syndrome. Neuropsychopharmacology 2013; 38:1460-71. [PMID: 23399948 PMCID: PMC3682140 DOI: 10.1038/npp.2013.44] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have previously shown that impulsivity in rats predicts the emergence of compulsive cocaine seeking and taking, and is coupled to decreased D2/3 receptor availability in the ventral striatum. As withdrawal from cocaine normalises high impulsivity in rats, we investigated, using positron emission tomography (PET), the effects of response-contingent cocaine administration on D2/3 receptor availability in the striatum. Rats were screened for impulsive behavior on the five-choice serial reaction time task. After a baseline PET scan with the D2/3 ligand [(18)F]fallypride, rats were trained to self-administer cocaine for 15 days under a long-access schedule. As a follow-up, rats were assessed for impulsivity and underwent a second [(18)F]fallypride PET scan. At baseline, we found that D2/3 receptor availability was significantly lower in the left, but not right, ventral striatum of high-impulsive rats compared with low-impulsive rats. While the number of self-administered cocaine infusions was not different between the two impulsivity groups, impulsivity selectively decreased in high-impulsive rats withdrawn from cocaine. This effect was accompanied by a significant increase in D2/3 receptor availability in the left, but not right, ventral striatum. We further report that D2/3 receptor availability was inversely related to baseline D2/3 receptor availability in the ventral striatum of high-impulsive rats, as well as to the left and right dorsal striatum of both low-impulsive and high-impulsive rats. These findings indicate that the reduction in impulsivity in high-impulsive rats by prior cocaine exposure may be mediated by a selective correction of deficient D2/3 receptor availability in the ventral striatum. A similar baseline-dependent mechanism may account for the therapeutic effects of stimulant drugs in clinical disorders such as ADHD.
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Affiliation(s)
- Daniele Caprioli
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - Young T Hong
- Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Stephen J Sawiak
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Valentina Ferrari
- Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - David J Williamson
- Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Bianca Jupp
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - T Adrian Carpenter
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Franklin I Aigbirhio
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Barry J Everitt
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - Trevor W Robbins
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - Tim D Fryer
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Clinical Neurosciences, University of Cambridge, Wolfson Brain Imaging Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Jeffrey W Dalley
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK,Department of Psychiatry, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK,Department of Psychology, University of Cambridge, Downing St, Cambridge CB2 3EB, UK. Tel: +44 0 1223 765 291; Fax: +44 0 1223 333 564. E-mail:
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Oei NYL, Rombouts SA, Soeter RP, van Gerven JM, Both S. Dopamine modulates reward system activity during subconscious processing of sexual stimuli. Neuropsychopharmacology 2012; 37:1729-37. [PMID: 22395731 PMCID: PMC3358742 DOI: 10.1038/npp.2012.19] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 02/03/2012] [Accepted: 02/07/2012] [Indexed: 12/18/2022]
Abstract
Dopaminergic medication influences conscious processing of rewarding stimuli, and is associated with impulsive-compulsive behaviors, such as hypersexuality. Previous studies have shown that subconscious subliminal presentation of sexual stimuli activates brain areas known to be part of the 'reward system'. In this study, it was hypothesized that dopamine modulates activation in key areas of the reward system, such as the nucleus accumbens, during subconscious processing of sexual stimuli. Young healthy males (n=53) were randomly assigned to two experimental groups or a control group, and were administered a dopamine antagonist (haloperidol), a dopamine agonist (levodopa), or placebo. Brain activation was assessed during a backward-masking task with subliminally presented sexual stimuli. Results showed that levodopa significantly enhanced the activation in the nucleus accumbens and dorsal anterior cingulate when subliminal sexual stimuli were shown, whereas haloperidol decreased activations in those areas. Dopamine thus enhances activations in regions thought to regulate 'wanting' in response to potentially rewarding sexual stimuli that are not consciously perceived. This running start of the reward system might explain the pull of rewards in individuals with compulsive reward-seeking behaviors such as hypersexuality and patients who receive dopaminergic medication.
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Affiliation(s)
- Nicole Y L Oei
- Leiden Institute for Brain and Cognition-LIBC, Leiden University, Leiden, The Netherlands.
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Abler B, Seeringer A, Hartmann A, Grön G, Metzger C, Walter M, Stingl J. Neural correlates of antidepressant-related sexual dysfunction: a placebo-controlled fMRI study on healthy males under subchronic paroxetine and bupropion. Neuropsychopharmacology 2011; 36:1837-47. [PMID: 21544071 PMCID: PMC3154102 DOI: 10.1038/npp.2011.66] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Sexual dysfunction is a common side effect of selective serotonin reuptake inhibitors (SSRIs) like paroxetine in the treatment of depression, imposing a considerable risk on medication adherence and hence therapeutic success. Bupropion, a norepinephrine and dopamine reuptake inhibitor, is recommended as an alternative treatment without adverse effects concerning sexual arousal and libido. We investigated the neural bases of paroxetine-related subjective sexual dysfunction when compared with bupropion and placebo. We scanned 18 healthy, heterosexual males in a randomized, double-blind, within-subject design while watching video clips of erotic and nonerotic content under steady-state conditions after taking 20 mg of paroxetine, 150 mg of bupropion, and placebo for 7 days each. Under paroxetine, ratings of subjective sexual dysfunction increased compared with placebo or bupropion. Activation along the anterior cingulate cortex (ACC), including subgenual, pregenual, and midcingulate cortices, in the ventral striatum and midbrain was decreased when compared with placebo. In contrast, bupropion let subjective ratings and ACC activations unchanged and increased activity of brain regions including posterior midcingulate cortex, mediodorsal thalamus, and extended amygdala relative to placebo and paroxetine. Brain regions that have been related to the processing of motivational (ventral striatum), emotional, and autonomic components of erotic stimulation (anterior cingulate) in previous studies showed reduced responsiveness under paroxetine in our study. Drug effects on these regions may be part of the mechanism underlying SSRI-related sexual dysfunction. Increased activation under bupropion may point to an opposite effect that may relate to the lack of impaired sexual functioning.
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Affiliation(s)
- Birgit Abler
- Department of Psychiatry, University of Ulm, Ulm, Germany.
| | - Angela Seeringer
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, University of Ulm, Ulm, Germany
| | | | - Georg Grön
- Department of Psychiatry, University of Ulm, Ulm, Germany
| | - Coraline Metzger
- Department of Psychiatry, Otto von Guericke-University, Magdeburg, Germany
| | - Martin Walter
- Department of Psychiatry, Otto von Guericke-University, Magdeburg, Germany
| | - Julia Stingl
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, University of Ulm, Ulm, Germany
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