TY - JOUR
T1 - Effect of tolcapone on brain activity during a variable attentional control task
T2 - A double-blind, placebo-controlled, counter-balanced trial in healthy volunteers
AU - Magalona, Sophia C.
AU - Rasetti, Roberta
AU - Chen, Jingshan
AU - Chen, Qiang
AU - Gold, Ian
AU - Decot, Heather
AU - Callicott, Joseph H.
AU - Berman, Karen F.
AU - Apud, José A.
AU - Weinberger, Daniel R.
AU - Mattay, Venkata S.
N1 - Funding Information:
This research was supported by direct funding of the Weinberger Lab in the Intramural Research Program of the National Institute of Mental Health, NIH, Bethesda, MD 20892, USA. and the Lieber Institute for Brain Development. We thank Saumitra Das, MS for his help with data acquisition.
PY - 2013/8
Y1 - 2013/8
N2 - Background: Attention is the capacity to flexibly orient behaviors and thoughts towards a goal by selecting and integrating relevant contextual information. The dorsal cingulate (dCC) and prefrontal (PFC) cortices play critical roles in attention. Evidence indicates that catechol-O- methyltransferase (COMT) modulates dopaminergic tone in the PFC and dCC. Objective: In this study, we explored the effect of tolcapone, a CNS penetrant COMT inhibitor that increases cortical dopamine levels, on brain activity during a Variable Attentional Control (VAC) task. Study Design: We performed a double-blinded, placebo-controlled, counter-balanced trial with tolcapone (Tasmar, tablets, 100 mg three times a day for 1 day and then 200 mg three times a day for 6 days; ClinicalTrials.gov identifier: NCT00044083). Setting: The study was conducted in the Clinical Center of the National Institute of Mental Health from 2005 to 2009. Patients: Twenty healthy volunteers (11 males; mean age = 32.7 years) with good imaging and performance data on both arms of the study were investigated. Intervention: Participants underwent 3T blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) while performing the event-related VAC task, which varies attention over three levels of load: LOW, INT (intermediate), and HIGH. Main Outcome Measure: Changes in behavioral data and individual contrast images were analyzed using ANOVA with drug and task load as co-factors. Results: There was a significant main effect of increasing task load, with resulting decreased accuracy and increased reaction time. While there was no significant effect of tolcapone on these behavioral measures, the neuroimaging data showed a significant effect on load-related changes in dCC, with significantly lower dCC activation on tolcapone compared with placebo. Further, neural activity in dCC correlated positively with COMT enzyme activity (i.e., lower COMT activity and presumably more dopamine was associated with lower activation in dCC, i.e., more efficient information processing). Conclusion: Our results show that pharmacological reduction of COMT activity modulates the engagement of attentional mechanisms, selectively enhancing the efficiency of dCC processing in healthy volunteers, reflected as decreased activity for the same level of performance.
AB - Background: Attention is the capacity to flexibly orient behaviors and thoughts towards a goal by selecting and integrating relevant contextual information. The dorsal cingulate (dCC) and prefrontal (PFC) cortices play critical roles in attention. Evidence indicates that catechol-O- methyltransferase (COMT) modulates dopaminergic tone in the PFC and dCC. Objective: In this study, we explored the effect of tolcapone, a CNS penetrant COMT inhibitor that increases cortical dopamine levels, on brain activity during a Variable Attentional Control (VAC) task. Study Design: We performed a double-blinded, placebo-controlled, counter-balanced trial with tolcapone (Tasmar, tablets, 100 mg three times a day for 1 day and then 200 mg three times a day for 6 days; ClinicalTrials.gov identifier: NCT00044083). Setting: The study was conducted in the Clinical Center of the National Institute of Mental Health from 2005 to 2009. Patients: Twenty healthy volunteers (11 males; mean age = 32.7 years) with good imaging and performance data on both arms of the study were investigated. Intervention: Participants underwent 3T blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) while performing the event-related VAC task, which varies attention over three levels of load: LOW, INT (intermediate), and HIGH. Main Outcome Measure: Changes in behavioral data and individual contrast images were analyzed using ANOVA with drug and task load as co-factors. Results: There was a significant main effect of increasing task load, with resulting decreased accuracy and increased reaction time. While there was no significant effect of tolcapone on these behavioral measures, the neuroimaging data showed a significant effect on load-related changes in dCC, with significantly lower dCC activation on tolcapone compared with placebo. Further, neural activity in dCC correlated positively with COMT enzyme activity (i.e., lower COMT activity and presumably more dopamine was associated with lower activation in dCC, i.e., more efficient information processing). Conclusion: Our results show that pharmacological reduction of COMT activity modulates the engagement of attentional mechanisms, selectively enhancing the efficiency of dCC processing in healthy volunteers, reflected as decreased activity for the same level of performance.
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U2 - 10.1007/s40263-013-0082-x
DO - 10.1007/s40263-013-0082-x
M3 - Review article
C2 - 23794107
AN - SCOPUS:84880799337
SN - 1172-7047
VL - 27
SP - 663
EP - 673
JO - CNS Drugs
JF - CNS Drugs
IS - 8
ER -