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Tomasi D, Manza P, Yan W, Shokri-Kojori E, Demiral ŞB, Yonga MV, McPherson K, Biesecker C, Dennis E, Johnson A, Zhang R, Wang GJ, Volkow ND. Examining the role of dopamine in methylphenidate's effects on resting brain function. Proc Natl Acad Sci U S A 2023; 120:e2314596120. [PMID: 38109535 PMCID: PMC10756194 DOI: 10.1073/pnas.2314596120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/14/2023] [Indexed: 12/20/2023] Open
Abstract
The amplitude of low-frequency fluctuations (ALFF) and global functional connectivity density (gFCD) are fMRI (Functional MRI) metrics widely used to assess resting brain function. However, their differential sensitivity to stimulant-induced dopamine (DA) increases, including the rate of DA rise and the relationship between them, have not been investigated. Here we used, simultaneous PET-fMRI to examine the association between dynamic changes in striatal DA and brain activity as assessed by ALFF and gFCD, following placebo, intravenous (IV), or oral methylphenidate (MP) administration, using a within-subject double-blind placebo-controlled design. In putamen, MP significantly reduced D2/3 receptor availability and strongly reduced ALFF and increased gFCD in the brain for IV-MP (Cohen's d > 1.6) but less so for oral-MP (Cohen's d < 0.6). Enhanced gFCD was associated with both the level and the rate of striatal DA increases, whereas decreased ALFF was only associated with the level of DA increases. These findings suggest distinct representations of neurovascular activation with ALFF and gFCD by stimulant-induced DA increases with differential sensitivity to the rate and the level of DA increases. We also observed an inverse association between gFCD and ALFF that was markedly enhanced during IV-MP, which could reflect an increased contribution from MP's vasoactive properties.
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Affiliation(s)
- Dardo Tomasi
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Peter Manza
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Weizheng Yan
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Ehsan Shokri-Kojori
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Şükrü Barış Demiral
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Michele-Vera Yonga
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Katherine McPherson
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Catherine Biesecker
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Evan Dennis
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Allison Johnson
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Rui Zhang
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Gene-Jack Wang
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
| | - Nora D. Volkow
- Laboratory of Neuroimaging (LNI), National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD20892
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Wallace PJ, Schultz Martins R, Scott JS, Steele SW, Greenway MJ, Cheung SS. The effects of acute dopamine reuptake inhibition on cognitive function during passive hyperthermia. Appl Physiol Nutr Metab 2020; 46:511-520. [PMID: 33232172 DOI: 10.1139/apnm-2020-0869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dopamine activity can modulate physical performance in the heat, but less is known about its effects on cognition during thermal stress. Twelves males completed a randomized, double-blinded protocol consisting of oral ingestion of 20 mg of methylphenidate (MPH) or placebo (lactose pill) during passive heating using a water-perfused suit (water temperature ∼49 °C). To identify the impact of peripheral versus central thermal strain, a cognitive test battery was completed at 4 different thermal states: baseline (BASE; 37.2 ± 0.6 °C core, 32.9 ± 0.7 °C skin), neutral core-hot skin (NC-HS; 37.2 ± 0.3 °C, 37.4 ± 0.3 °C), hyperthermic core-hot skin (HC-HS; 38.7 ± 0.4 °C, 38.7 ± 0.2 °C), and hyperthermic core-cooled skin (HC-CS; 38.5 ± 0.4 °C, 35.1 ± 0.8 °C). The cognitive test battery consisted of the 2-back task (i.e., working memory), set-shifting (i.e., executive function), Groton Maze Learning Task (i.e., executive function) and detection task (i.e., psychomotor processing). MPH led to significantly higher heart rates (∼5-15 b·min-1) at BASE, NC-HS, and HC-HS (all p < 0.05). There were no significant differences in the number of errors made on each task (all p < 0.05). Participants were significantly faster (p < 0.05) on the set-shifting task in the HC-HS timepoint, irrespective of drug condition (p > 0.05). In summary, we demonstrated that 20 mg of MPH did not significantly alter cognitive function during either normothermia or moderate hyperthermia. Novelty: Twenty milligrams of MPH did not significantly alter cognitive function during passive heat stress. MPH led to significant higher heart rates (∼5-15 b·min-1) in thermoneutral and during passive heat stress. Future studies are needed to determine the mechanisms of why MPH improves physical but not cognitive performance during heat stress.
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Affiliation(s)
- Phillip J Wallace
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Ricardo Schultz Martins
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Jake S Scott
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Scott W Steele
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Mathew J Greenway
- Department of Family Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Stephen S Cheung
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
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Evers EA, Stiers P, Ramaekers JG. High reward expectancy during methylphenidate depresses the dopaminergic response to gain and loss. Soc Cogn Affect Neurosci 2017; 12:311-318. [PMID: 27677943 PMCID: PMC5390715 DOI: 10.1093/scan/nsw124] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 07/13/2016] [Accepted: 08/24/2016] [Indexed: 01/07/2023] Open
Abstract
Dopamine plays an important role in goal-directed behavior, through its modulatory influence on striatal neurons. It is unclear whether tonic dopamine levels, which regulate the vigor of acting, interact with the phasic dopamine response to reward that drives instrumental behavior. In a randomized placebo-controlled study in healthy volunteers, we show that methylphenidate, a drug that increases tonic dopamine levels, systematically reduced striatal phasic BOLD responses to gain and loss in a gambling task as measured with fMRI. It also increased response vigor and reward expectancy-related BOLD signals in the ventral striatum. These findings suggest that striatal tonic dopamine levels constitute an average reward expectation signal that modulates the phasic dopaminergic response to reward. This offers opportunities for treatment of behavioral disorders associated with abnormal reward sensitivity.
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Affiliation(s)
- E A Evers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, The Netherlands
| | - P Stiers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, The Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, The Netherlands
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Chen W, Liu P, Volkow ND, Pan Y, Du C. Cocaine attenuates blood flow but not neuronal responses to stimulation while preserving neurovascular coupling for resting brain activity. Mol Psychiatry 2016; 21:1408-16. [PMID: 26666202 PMCID: PMC4925321 DOI: 10.1038/mp.2015.185] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 09/02/2015] [Accepted: 10/05/2015] [Indexed: 12/16/2022]
Abstract
Cocaine affects neuronal activity and constricts cerebral blood vessels, making it difficult to determine whether cocaine-induced changes in cerebral blood flow (CBF) reflect neuronal activation or its vasoactive effects. Here we assessed the effects of acute cocaine on both resting-state and stimulation responses to investigate cocaine's effects on neurovascular coupling and to differentiate its effects on neuronal activity from its vasoactive actions. We concurrently measured cortical field potentials via thinned-skull electroencephalography recordings and CBF with laser Doppler flowmetry in the rat's somatosensory cortex for both resting state and forepaw stimulation before and following cocaine administration (1 mg kg(-1), intravenously). Results show both resting-state field potentials and CBF were depressed after cocaine administration (19.8±4.7% and 52.1±13.4%, respectively) and these changes were strongly correlated with each other (r=0.81, P<0.001), indicating that cocaine did not affect neurovascular coupling at rest and that the reduction in resting CBF reflected reduction in synchronized spontaneous neuronal activity rather than vasoconstriction. In contrast, the forepaw stimulation-evoked neuronal activity was not changed by cocaine (P=0.244), whereas the CBF to the stimulation was reduced 49.9±2.6% (P=0.028) gradually recovering ∼20 min after cocaine injection, indicating that neurovascular coupling during stimulation was temporarily disrupted by cocaine. Neurovascular uncoupling by cocaine during stimulation but not during rest indicates that distinct processes might underlie neurovascular regulation for both stimulation and spontaneous activity. The greater reductions by cocaine to the stimulation-induced CBF increases than to the background CBF should be considered when interpreting functional MRI studies comparing activation responses between controls and cocaine abusers. Neurovascular uncoupling could contribute to cocaine's neurotoxicity, particularly for stimulation conditions when CBF might be insufficient to cover for the energetic demands of neuronal tissue.
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Affiliation(s)
- Wei Chen
- Departments of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794
| | - Peng Liu
- Departments of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892
| | - Yingtian Pan
- Departments of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794
| | - Congwu Du
- Departments of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794
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Decreased dopamine brain reactivity in marijuana abusers is associated with negative emotionality and addiction severity. Proc Natl Acad Sci U S A 2014; 111:E3149-56. [PMID: 25024177 DOI: 10.1073/pnas.1411228111] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Moves to legalize marijuana highlight the urgency to investigate effects of chronic marijuana in the human brain. Here, we challenged 48 participants (24 controls and 24 marijuana abusers) with methylphenidate (MP), a drug that elevates extracellular dopamine (DA) as a surrogate for probing the reactivity of the brain to DA stimulation. We compared the subjective, cardiovascular, and brain DA responses (measured with PET and [(11)C]raclopride) to MP between controls and marijuana abusers. Although baseline (placebo) measures of striatal DA D2 receptor availability did not differ between groups, the marijuana abusers showed markedly blunted responses when challenged with MP. Specifically, compared with controls, marijuana abusers had significantly attenuated behavioral ("self-reports" for high, drug effects, anxiety, and restlessness), cardiovascular (pulse rate and diastolic blood pressure), and brain DA [reduced decreases in distribution volumes (DVs) of [(11)C]raclopride, although normal reductions in striatal nondisplaceable binding potential (BPND)] responses to MP. In ventral striatum (key brain reward region), MP-induced reductions in DVs and BPND (reflecting DA increases) were inversely correlated with scores of negative emotionality, which were significantly higher for marijuana abusers than controls. In marijuana abusers, DA responses in ventral striatum were also inversely correlated with addiction severity and craving. The attenuated responses to MP, including reduced decreases in striatal DVs, are consistent with decreased brain reactivity to the DA stimulation in marijuana abusers that might contribute to their negative emotionality (increased stress reactivity and irritability) and addictive behaviors.
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Schouw MLJ, Caan MWA, Geurts HM, Schmand B, Booij J, Nederveen AJ, Reneman L. Monoaminergic dysfunction in recreational users of dexamphetamine. Eur Neuropsychopharmacol 2013; 23:1491-502. [PMID: 23415394 DOI: 10.1016/j.euroneuro.2013.01.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 01/16/2013] [Accepted: 01/18/2013] [Indexed: 11/27/2022]
Abstract
Preclinical studies suggest that dexamphetamine (dAMPH) can lead to monoaminergic neurotoxicity. This exploratory study aimed to investigate effects of recreational dAMPH use on the dopamine (DA) and noradrenaline (NA) systems in humans. To that purpose, eight male abstinent dAMPH (26.0 ± 4.0 years) users and 10 age- and IQ-matched male healthy control subjects (23.0 ± 3.8) underwent neuropsychological testing sensitive to DAergic function and single photon emission computed tomography (SPECT) scanning with [(123)I]FP-CIT to determine striatal DA transporter (DAT) binding. In addition, changes in cerebral blood flow (CBF) induced by the DA/NA reuptake inhibitor methylphenidate (MPH) were measured using pharmacological magnetic resonance imaging (phMRI). Performance of dAMPH users was significantly worse on executive function and verbal memory tasks. Striatal DAT binding ratios were on average lower in dAMPH users (near-significant, p=0.05). In addition, CBF in control subjects decreased significantly in response to MPH in gray matter and basal ganglia, among which the striatum, thalamus and hippocampus by 10% to 29%. However, in dAMPH users the CBF response was blunted in most brain areas studied, only decreasing in the hippocampus and orbitofrontal cortex. When comparing groups, CBF response was found to be significantly different in the thalamus with a decrease for healthy controls and a blunted response in dAMPH users. Collectively, our findings of a blunted hemodynamic response in monoaminergic regions, in combination with indications for lower striatal DAT binding and poorer behavioral measures are likely to represent DAergic dysfunction in dAMPH users, although NAergic dysfunction may also play a role.
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Affiliation(s)
- M L J Schouw
- Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Brain Imaging Center at the Academic Medical Centre, Amsterdam, The Netherlands.
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Depue RA, Fu Y. On the nature of extraversion: variation in conditioned contextual activation of dopamine-facilitated affective, cognitive, and motor processes. Front Hum Neurosci 2013; 7:288. [PMID: 23785330 PMCID: PMC3682132 DOI: 10.3389/fnhum.2013.00288] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 06/02/2013] [Indexed: 12/25/2022] Open
Abstract
Research supports an association between extraversion and dopamine (DA) functioning. DA facilitates incentive motivation and the conditioning and incentive encoding of contexts that predict reward. Therefore, we assessed whether extraversion is related to the efficacy of acquiring conditioned contextual facilitation of three processes that are dependent on DA: motor velocity, positive affect, and visuospatial working memory. We exposed high and low extraverts to three days of association of drug reward (methylphenidate, MP) with a particular laboratory context (Paired group), a test day of conditioning, and three days of extinction in the same laboratory. A Placebo group and an Unpaired group (that had MP in a different laboratory context) served as controls. Conditioned contextual facilitation was assessed by (i) presenting video clips that varied in their pairing with drug and laboratory context and in inherent incentive value, and (ii) measuring increases from day 1 to Test day on the three processes above. Results showed acquisition of conditioned contextual facilitation across all measures to video clips that had been paired with drug and laboratory context in the Paired high extraverts, but no conditioning in the Paired low extraverts (nor in either of the control groups). Increases in the Paired high extraverts were correlated across the three measures. Also, conditioned facilitation was evident on the first day of extinction in Paired high extraverts, despite the absence of the unconditioned effects of MP. By the last day of extinction, responding returned to day 1 levels. The findings suggest that extraversion is associated with variation in the acquisition of contexts that predict reward. Over time, this variation may lead to differences in the breadth of networks of conditioned contexts. Thus, individual differences in extraversion may be maintained by activation of differentially encoded central representations of incentive contexts that predict reward.
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Methylphenidate modulates sustained attention and cortical activation in survivors of traumatic brain injury: a perfusion fMRI study. Psychopharmacology (Berl) 2012; 222:47-57. [PMID: 22203319 PMCID: PMC3369011 DOI: 10.1007/s00213-011-2622-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022]
Abstract
RATIONALE Methylphenidate (MPH), the most widely prescribed psychostimulant to treat many neuropsychiatric conditions, is reported to improve attention and speed of processing in survivors of traumatic brain injury (TBI). The neural correlate of this efficacy, however, remains unclear. OBJECTIVE Using perfusion functional magnetic resonance imaging (fMRI) as a biomarker of regional neural activity, the current study aimed to examine the neural correlates of single-dose (0.3 mg/kg) MPH administration in a randomized double-blind placebo-controlled crossover study design. METHODS Twenty-three individuals with moderate to severe TBI were tested on two occasions approximately 1 week apart. Perfusion fMRI scanning was carried out at rest and while participants performed cognitive tasks requiring sustained attention and working memory. RESULTS Behaviorally, MPH significantly improved both accuracy and reaction time (RT) in the sustained attention task but only RT in the working memory task. A trend of global reduction of cerebral blood flow by MPH was observed in all task conditions including resting. Voxel-wise whole-brain analysis revealed an interaction effect of drug by condition (MPH-placebo X task-rest) for the sustained attention task in the left posterior superior parietal cortex and parieto-occipital junction (BA 7/19). The magnitude of drug-related deactivation of this area during task performance was correlated with improvement in RT. CONCLUSION Suppression of activity in this area during task performance may reflect a compensatory mechanism by which MPH ameliorates attention impairments in TBI.
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Udo de Haes JI, Maguire RP, Jager PL, Paans AMJ, den Boer JA. Methylphenidate-induced activation of the anterior cingulate but not the striatum: a [15O]H2O PET study in healthy volunteers. Hum Brain Mapp 2007; 28:625-35. [PMID: 17080442 PMCID: PMC6871329 DOI: 10.1002/hbm.20293] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The dopaminergic system has been implicated in the pathogenesis and treatment of a variety of neuropsychiatric disorders, such as schizophrenia, depression, and addiction. (Dys)function of the dopaminergic system may be studied by combining [15O]H2O PET with a dopaminergic drug challenge. In this pilot study we investigated the suitability of the dopamine reuptake blocker methylphenidate (MP) as a dopaminergic probe. Measurements of regional cerebral blood flow (rCBF) were made at 10 and 30 min after placebo and MP (0.25 mg/kg) injection to seven healthy volunteers. During scanning the behavioral condition of the subjects was standardized using a continuous performance task. Growth hormone levels were assessed and subjective ratings were obtained. MP significantly elevated growth hormone levels. After receiving MP, the subjective experience varied from neutral to highly pleasurable. Ten minutes after MP administration, significant relative increases in rCBF were found in the rostral anterior cingulate (AC), temporal poles, and the supplementary motor area. Significant reductions were seen in the superior temporal gyri, right medial frontal gyrus, and right inferior parietal cortex. At 30 min after MP administration, increases were seen in the AC, temporal pole, and right cerebellum. No changes were observed in the striatum. The activation in the right rostral AC was significantly higher in the subjects with the highest euphoria scores compared to the subjects with minimal MP-induced changes in euphoria. We suggest that the combined MP challenge with functional imaging, as described in our study, may be a useful tool to study the functional integrity of the dopaminergic system in psychiatric disorders.
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Affiliation(s)
- Joanna I Udo de Haes
- Department of Biological Psychiatry, University Medical Center Groningen, Groningen, The Netherlands.
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Montgomery AJ, Asselin MC, Farde L, Grasby PM. Measurement of methylphenidate-induced change in extrastriatal dopamine concentration using [11C]FLB 457 PET. J Cereb Blood Flow Metab 2007; 27:369-77. [PMID: 16685253 DOI: 10.1038/sj.jcbfm.9600339] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
[(11)C]FLB 457 is a very high-affinity radiotracer that allows the measurement of dopamine D(2/3) receptor availability in regions of the brain where densities are very low, such as the cerebral cortex. It is not known if [(11)C]FLB 457 binding is sensitive to the concentration of endogenous dopamine in humans in a manner analogous to [(11)C]raclopride and [(123)I]IBZM in the striatum. To test this possibility, extrastriatal [(11)C]FLB 457 binding was measured at baseline and after the oral administration of 40 to 60 mg of the psychostimulant methylphenidate (MP) in 12 healthy volunteers using positron emission tomography (PET) in a balanced-order, double-blind design. The dynamic PET data were quantified using a two-tissue compartment model with a metabolite-corrected arterial plasma input function. Two volunteers were excluded because of excessive head movement. In the remainder, MP caused significant reductions in the volume of distribution (VD) in temporal and frontal cortical regions and thalamus, suggesting that [(11)C]FLB 457 binding is sensitive to endogenous dopamine concentration. Moreover, the change in [(11)C]FLB 457 binding after MP correlated with the dose of MP (in mg/kg body weight) in all regions assessed. We conclude that MP in doses within the therapeutic range for the treatment of attention deficit hyperactivity disorder causes increases in dopamine concentrations in extrastriatal regions and that [(11)C]FLB 457 PET may be a useful tool for the assessment of change in dopamine concentration in these areas in humans.
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Affiliation(s)
- Andrew J Montgomery
- MRC Clinical Sciences Centre, Cyclotron Building, Imperial College, Hammersmith Hospital, London, UK.
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Silveri MM, Anderson CM, McNeil JF, Diaz CI, Lukas SE, Mendelson JH, Renshaw PF, Kaufman MJ. Oral methylphenidate challenge selectively decreases putaminal T2 in healthy subjects. Drug Alcohol Depend 2004; 76:173-80. [PMID: 15488341 DOI: 10.1016/j.drugalcdep.2004.04.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2003] [Revised: 02/05/2004] [Accepted: 04/26/2004] [Indexed: 11/18/2022]
Abstract
Despite the recent rise in oral methylphenidate (MPH) abuse, few studies have characterized the time course of oral MPH brain effects in human subjects. Accordingly, this study assessed the hemodynamic effects of oral MPH effects in 11 healthy young adults (six women), by measuring brain transverse relaxation times (T2). T2 can be interpreted as a surrogate marker for, and inversely correlated with, steady-state cerebral blood volume (CBV). Data were acquired from the caudate nucleus, putamen, and thalamus, using a 1.5 T MRI scanner at baseline and serially for 2 h following oral MPH administration (0.5 mg/kg). Physiological and subjective measures and plasma MPH levels also were examined. MPH induced a selective T2 decrease (-1.65+/-0.53 ms) in the putamen (F(6,54)=2.68, P<0.03). Heartrate, blood pressure and plasma MPH levels increased significantly after drug administration, as well as subjective ratings of "feeling drug effect". T2 decreases may reflect MPH-induced increases in putaminal blood volume. These data suggest that T2 relaxometry can be used to study the time course of regional cerebral blood volume responses to MPH and perhaps to other stimulant drugs.
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Affiliation(s)
- Marisa M Silveri
- Brain Imaging Center, McLean Hospital & Department of Psychiatry, Harvard Medical School, Belmont, MA 02478, USA
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Bray CL, Cahill KS, Oshier JT, Peden CS, Theriaque DW, Flotte TR, Stacpoole PW. Methylphenidate Does Not Improve Cognitive Function in Healthy Sleep-Deprived Young Adults. J Investig Med 2004. [DOI: 10.1177/108155890405200335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Abuse of methylphenidate, a treatment of attention-deficit/hyperactivity disorder, is reported to be increasing among students for the purpose of improving cognition. Methods A single capsule, containing methylphenidate (20 mg) or placebo, was administered to healthy young adults orally following 24 hours of sleep deprivation. Measurements included percent change in score from sleep-deprived baseline on four standardized tests of cognitive function: Hopkins Verbal Learning, Digit Span, Modified Stroop, and Trail Making tests. Measurements also included percent changes in blood pressure and heart rate from sleep-deprived baseline and plasma methylphenidate concentration. Results Differences in cognitive test performance were not observed between intervention groups. In subjects receiving methylphenidate, mean percent changes from baseline for systolic blood pressure and heart rate were increased relative to placebo between 90 and 210 minutes following capsule administration (maximum increases of 9.45% and 11.03%, respectively). The timing of peak differences in physiologic measures did not correlate with peak serum methylphenidate concentrations. Exit questionnaire ratings of “capsule effect” and perceived performance on the postcapsule administration of the most challenging cognitive test were both higher ( p = .044 and p = .009, respectively) for the methylphenidate group than for the placebo group. Conclusions: Cognitive improvement among sleep-deprived young adults was not observed following methylphenidate administration. Benefits perceived by abusers may relate to increased confidence and sense of well-being, as well as to sympathetic nervous system stimulation. Moreover, methylphenidate administration results in physiologic effects that could be harmful to certain individuals.
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Affiliation(s)
| | - Kevin S. Cahill
- MD/PhD Program, University of Florida College of Medicine, Gainesville, FL
| | - Joseph T. Oshier
- MD/PhD Program, University of Florida College of Medicine, Gainesville, FL
| | - Carmen S. Peden
- MD/PhD Program, University of Florida College of Medicine, Gainesville, FL
| | - Douglas W. Theriaque
- General Clinical Research Center, University of Florida College of Medicine, Gainesville, FL
| | - Terence R. Flotte
- Powell Gene Therapy Center, University of Florida Genetics Institute, University of Florida College of Medicine, Gainesville, FL
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL
| | - Peter W. Stacpoole
- General Clinical Research Center, University of Florida College of Medicine, Gainesville, FL
- Department of Medicine (Division of Endocrinology and Metabolism), University of Florida College of Medicine, Gainesville, FL
- MD/PhD Program, University of Florida College of Medicine, Gainesville, FL
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Chang L, Grob CS, Ernst T, Itti L, Mishkin FS, Jose-Melchor R, Poland RE. Effect of ecstasy [3,4-methylenedioxymethamphetamine (MDMA)] on cerebral blood flow: a co-registered SPECT and MRI study. Psychiatry Res 2000; 98:15-28. [PMID: 10708923 DOI: 10.1016/s0925-4927(99)00048-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
3,4-methylenedioxymethamphetamine (MDMA), an illicit recreational drug, damages serotonergic nerve endings. Since the cerebrovasculature is regulated partly by the serotonergic system, MDMA may affect cerebral blood flow (CBF) in humans. We evaluated 21 abstinent recreational MDMA users and 21 age- and gender-matched healthy subjects with brain SPECT and MRI. Ten of the MDMA subjects also had repeat SPECT and MRI after receiving two doses of MDMA. Abstinent MDMA users showed no significantly different global or regional CBF (rCBF) compared to the control subjects. However, within 3 weeks after MDMA administration, rCBF remained decreased in the visual cortex, the caudate, the superior parietal and dorsolateral frontal regions compared to baseline rCBF. The decreased rCBF tended to be more pronounced in subjects who received the higher dosage of MDMA. Two subjects who were scanned at 2-3 months after MDMA administration showed increased rather than decreased rCBF. Low-dose recreational MDMA use does not cause detectable persistent rCBF changes in humans. The lack of long-term rCBF changes may be due to a non-significant effect of serotonergic deficits on rCBF, or regeneration of serotonergic nerve terminals. The subacute decrease in rCBF after MDMA administration may be due to the direct effect of MDMA on the serotonergic system or the indirect effects of its metabolites on the dopaminergic system; the preliminary data suggest these effects may be transient.
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Affiliation(s)
- L Chang
- Department of Neurology, UCLA School of Medicine, Harbor-UCLA Medical Center, 1000 W. Carson Street, B-4, Torrance, CA 90509, USA.
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Gollub RL, Breiter HC, Kantor H, Kennedy D, Gastfriend D, Mathew RT, Makris N, Guimaraes A, Riorden J, Campbell T, Foley M, Hyman SE, Rosen B, Weisskoff R. Cocaine decreases cortical cerebral blood flow but does not obscure regional activation in functional magnetic resonance imaging in human subjects. J Cereb Blood Flow Metab 1998; 18:724-34. [PMID: 9663502 DOI: 10.1097/00004647-199807000-00003] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The authors used functional magnetic resonance imaging (fMRI) to determine whether acute intravenous (i.v.) cocaine use would change global cerebral blood flow (CBF) or visual stimulation-induced functional activation. They used flow-sensitive alternating inversion recovery (FAIR) scan sequences to measure CBF and blood oxygen level-dependent (BOLD) sensitive T2* scan sequences during visual stimulation to measure neuronal activation before and after cocaine and saline infusions. Cocaine (0.6 mg/kg i.v. over 30 seconds) increased heart rate and mean blood pressure and decreased end tidal carbon dioxide (CO2). All measures returned to baseline by 2 hours, the interinfusion interval, and were unchanged by saline. Flow-sensitive alternating inversion recovery imaging demonstrated that cortical gray matter CBF was unchanged after saline infusion (-2.4 +/- 6.5%) but decreased (-14.1 +/- 8.5%) after cocaine infusion (n = 8, P < 0.01). No decreases were detected in white matter, nor were changes found comparing BOLD signal intensity in cortical gray matter immediately before cocaine infusion with that measured 10 minutes after infusion. Visual stimulation resulted in comparable BOLD signal increases in visual cortex in all conditions (before and after cocaine and saline infusion). Despite a small (14%) but significant decrease in global cortical gray matter CBF after acute cocaine infusion, specific regional increases in BOLD imaging, mediated by neurons, can be measured reliably.
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Affiliation(s)
- R L Gollub
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston 02129, USA
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15
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Affiliation(s)
- S J Gatley
- Medical Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
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Mach RH, Nader MA, Ehrenkaufer RL, Line SW, Smith CR, Gage HD, Morton TE. Use of positron emission tomography to study the dynamics of psychostimulant-induced dopamine release. Pharmacol Biochem Behav 1997; 57:477-86. [PMID: 9218272 DOI: 10.1016/s0091-3057(96)00449-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Microdialysis studies have shown that psychostimulants act through a common neurochemical mechanism of elevating synaptic dopamine content in the mesocorticolimbic dopaminergic system. However, little information is available regarding the dynamics of the interaction between the elevated synaptic dopamine levels induced by a psychostimulant and postsynaptic dopamine receptors. The goal of the current investigation was to determine if positron emission tomography (PET) studies using the dopamine D2-selective radioligand [18F]4'-fluoroclebopride ([18F]FCP) could be used to measure synaptic dopamine levels. Rhesus monkeys were used because our previous studies revealed that [18F]FCP has a low test/retest variability in this species. Under control conditions, [18F]FCP had a high uptake and slow rate of washout from the basal ganglia, a region of brain that expresses a high density of D2 receptors, reaching kinetic equilibrium at approximately 40 min. Challenge studies, each separated by at least 1 month, were conducted by administering an intravenous dose of (-)cocaine, d-amphetamine, methylphenidate, or d-methamphetamine (1.0 mg/kg) at 40 min post-IV injection of a no-carrier-added dose of [18F]FCP. In each case, the psychostimulant caused an increase in the rate of washout of [18F]FCP from the basal ganglia. Methamphetamine and amphetamine had more pronounced effects on the washout kinetics of [18F]FCP relative to cocaine and methylphenidate, a result that is consistent with the ability of each drug to elevate synaptic dopamine levels. Our results indicate that challenge studies with [18F]FCP may be a useful technique for studying the dynamics of the interaction between psychostimulant-induced increases in synaptic dopamine and postsynaptic D2 receptors.
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Affiliation(s)
- R H Mach
- Department of Radiology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC 27157, USA
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Booij J, Korn P, Linszen DH, van Royen EA. Assessment of endogenous dopamine release by methylphenidate challenge using iodine-123 iodobenzamide single-photon emission tomography. EUROPEAN JOURNAL OF NUCLEAR MEDICINE 1997; 24:674-7. [PMID: 9169577 DOI: 10.1007/bf00841408] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This double-blind, placebo-controlled study assessed pharmacologically induced endogenous dopamine (DA) release in healthy male volunteers (n=12). Changes in endogenous DA release after injection of the psychostimulant drug methylphenidate were evaluated by single-photon emission tomography (SPET) and constant infusion of iodine-123 iodobenzamide ([123I]IBZM), a D2 receptor radioligand that is sensitive to endogenous DA release. Methylphenidate induced displacement of striatal [123I]IBZM binding, resulting in a significantly decrease in the specific to non-specific [123I]IBZM uptake ratio (average: 8.6%) in comparison with placebo (average: -1.9%). Moreover, injection of methylphenidate induced significant behavioural responses on the following items: excitement, anxiety, tension, and mannerisms and posturing. The results of this study demonstrate the feasibility of using constant infusion of [123I]IBZM and SPET imaging to measure endogenous DA release after methylphenidate challenge and to investigate neurochemical aspects of behaviour.
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Affiliation(s)
- J Booij
- Graduate School of Neurosciences, Department of Nuclear Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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