Dopaminergic Modulation of Cognition and Psychomotor Function

Study Overview
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Brief Summary
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A recent study at our lab showed increased episodic memory consolidation and response readiness after treatment with methylphenidate in healthy volunteers. The investigators seek to replicate and extend these findings. Furthermore the pharmacological specificity of these effects will be studied. Since methylphenidate has an effect on two neurotransmitters, dopamine and noradrenaline, either could be responsible for the observed effects. In order to explore the dopaminergic contribution to this effect, the study proposed here includes not only methylphenidate but also levodopa/carbidopa, which only affects dopamine and not noradrenaline. In this study, 20 healthy males and females between 18 and 45 years of age will participate. They will be recruited via advertisements at Maastricht University and in local newspapers. Participants will be treated once with methylphenidate, once with levodopa/carbidopa and once with placebo. All medications will be administered orally with a capsule. It is hypothesized that methylphenidate and levodopa/carbidopa will both enhance episodic memory consolidation and improve response readiness

Official Title
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Dopaminergic Modulation of Cognition and Psychomotor Function

Conditions
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Dopamine Activity, Episodic Memory Consolidation, Response Preparation

Intervention / Treatment
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* Drug: Methylphenidate 40 mg
* Drug: Levodopa/carbidopa 125 mg
* Drug: Domperidon 10 mg


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female 18 to 45 years of age Healthy (i.e. absence of all exclusion criteria), normal static binocular acuity (corrected or uncorrected), Body mass index between 18.5 and 30 Willingness to sign an informed consent. Exclusion Criteria: history of cardiac, hepatic, renal, pulmonary, neurological, gastrointestinal, haematological or psychiatric illness. history of depression, bipolar disorder, anxiety disorder, panic disorder, psychosis, or attention deficit hyperactivity disorder will be excluded from participation. first-degree relative with a psychiatric disorder or a history with a psychiatric disorder excessive drinking (>20 glasses of alcohol containing beverages a week pregnancy or lactation use of medication other than oral contraceptives use of recreational drugs from 2 weeks before until the end of the experiment any condition in which gastrointestinal motility might carry any risk any sensory or motor deficits which could reasonably be expected to affect test performance

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Medication<br>In this study, a crossover design is applied. All participants receive all three treatments in randomized order on separate days. | Drug: Methylphenidate 40 mg<br>* Oral dose 40 mg<br>* Other names: Ritalin RVG 03957;Drug: Levodopa/carbidopa 125 mg<br>* oral dose, 100 mg levodopa, 25 mg carbidopa in one capsule<br>* Other names: Sinemet RVG08740;Drug: Domperidon 10 mg<br>* Domperidon 10 mg<br>* Other names: Domperidon RVG 23565;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavioral score on the Word learning test | Number of words recalled in the word learning test | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CNV amplitude | Amplitude of the CNV wave in the EEG | 1 day | 
| Reaction time on the CNV | Reaction time in the response preparation task in which CNV is measured | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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dopamine, EEG, episodic memory, contingent negative variation, response preparation, levodopa, methylphenidate