{"id":"8bcc3e9d-7235-5595-9213-989052e96f37","stable_key":"6660bba2-4fa0-590a-bf52-9803a24bea9f:human-dat-pet","predicate":"decreases_in_recorded_experiment","statement":"In ten healthy men, 200 or 400 mg oral modafinil reduced DAT-radiotracer binding by about 54% in caudate, 47% in putamen and 39% in nucleus accumbens.","claim_class":"mechanistic","status":"source_recorded","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"da6c175b-4fa8-586d-ad14-06204cb343d1","mechanism_event_label":"In ten healthy men, 200 or 400 mg oral modafinil reduced DAT-radiotracer binding by about 54% in caudate, 47% in putamen and 39% in nucleus accumbens.","subject":{"id":"624e6a4b-f96d-5d12-8206-30d1e1715c26","slug":"modafinil","display_name":"Modafinil","entity_type_key":"drug"},"object":{"id":"9e5c68df-f041-565a-8c77-b1282ff645eb","slug":"slc6a3","display_name":"Human dopamine transporter / DAT / SLC6A3","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"da6c175b-4fa8-586d-ad14-06204cb343d1","stable_key":"6660bba2-4fa0-590a-bf52-9803a24bea9f:human-dat-pet-event","event_type":"biochemical_relationship","label":"In ten healthy men, 200 or 400 mg oral modafinil reduced DAT-radiotracer binding by about 54% in caudate, 47% in putamen and 39% in nucleus accumbens.","description":"In a PET study of **10 healthy men**, oral 200 or 400 mg modafinil reduced transporter-radiotracer binding by approximately **54% in caudate, 47% in putamen and 39% in nucleus accumbens**. Separate raclopride measurements supported increased extracellular dopamine. DAT occupancy is not a percentage increase in dopamine; raclopride displacement is an indirect imaging indicator rather than direct chemical sampling. [Volkow et al., 2009](https://pubmed.ncbi.nlm.nih.gov/19293415/)","status":"provisional","compartment":null,"participants":[{"entity":{"id":"624e6a4b-f96d-5d12-8206-30d1e1715c26","slug":"modafinil","display_name":"Modafinil","entity_type_key":"drug"},"role":"tested factor","stoichiometry":null,"state_label":"Oral modafinil 200 or 400 mg","sequence_order":0,"notes":""},{"entity":{"id":"9e5c68df-f041-565a-8c77-b1282ff645eb","slug":"slc6a3","display_name":"Human dopamine transporter / DAT / SLC6A3","entity_type_key":"protein"},"role":"measured outcome","stoichiometry":null,"state_label":"decrease","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary indexed abstract checked; full methods and figures not comprehensively reviewed.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_contrast","value_text":"{\"intervention\": \"Oral modafinil 200 or 400 mg\", \"comparator\": \"Baseline/placebo comparison\", \"endpoint\": \"In ten healthy men, 200 or 400 mg oral modafinil reduced DAT-radiotracer binding by about 54% in caudate, 47% in putamen and 39% in nucleus accumbens.\", \"effect_direction\": \"decrease\", \"combination\": \"single\", \"conditions\": []}","comparator":null,"unit":null,"notes":"Explicit extracted experimental comparison; source-derived draft.","entity":null},{"dimension":"experimental_model","value_text":"Human PET, ten healthy men; transporter occupancy is not percent dopamine increase.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Interpret only within the recorded preparation, exposure and comparator. 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Separate raclopride measurements supported increased extracellular dopamine. DAT occupancy is not a percentage increase in dopamine; raclopride displacement is an indirect imaging indicator rather than direct chemical sampling. [Volkow et al., 2009](https://pubmed.ncbi.nlm.nih.gov/19293415/)","model_system":"Human PET, ten healthy men; transporter occupancy is not percent dopamine increase.","directness":"reported_statement","verification_status":"source_recorded","notes":"Exact excerpt of the retained AI-assisted reviewed reference; primary sources are cited in primary_references and access scope is retained. 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