{"id":"8a2d45f1-1566-5f47-a05f-1c795d8e63d8","stable_key":"6660bba2-4fa0-590a-bf52-9803a24bea9f:human-dopamine-pet","predicate":"increases_in_recorded_experiment","statement":"Separate raclopride PET measurements after oral modafinil supported increased extracellular dopamine; radiotracer displacement is an indirect indicator, not chemical sampling.","claim_class":"observational","status":"source_recorded","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"76d6996d-e6fd-5b2f-80c8-d2c138eb8344","mechanism_event_label":"Separate raclopride PET measurements after oral modafinil supported increased extracellular dopamine; radiotracer displacement is an indirect indicator, not chemical sampling.","subject":{"id":"624e6a4b-f96d-5d12-8206-30d1e1715c26","slug":"modafinil","display_name":"Modafinil","entity_type_key":"drug"},"object":{"id":"9cca6209-0603-5ab7-96ad-2f3ae4b772d2","slug":"dopamine","display_name":"Dopamine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"76d6996d-e6fd-5b2f-80c8-d2c138eb8344","stable_key":"6660bba2-4fa0-590a-bf52-9803a24bea9f:human-dopamine-pet-event","event_type":"experimental_observation","label":"Separate raclopride PET measurements after oral modafinil supported increased extracellular dopamine; radiotracer displacement is an indirect indicator, not chemical sampling.","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","sequence_order":0,"notes":""},{"entity":{"id":"9cca6209-0603-5ab7-96ad-2f3ae4b772d2","slug":"dopamine","display_name":"Dopamine","entity_type_key":"small_molecule"},"role":"measured outcome","stoichiometry":null,"state_label":"increase","sequence_order":1,"notes":""},{"entity":{"id":"9e5c68df-f041-565a-8c77-b1282ff645eb","slug":"slc6a3","display_name":"Human dopamine transporter / DAT / SLC6A3","entity_type_key":"protein"},"role":"engaged transporter","stoichiometry":null,"state_label":"","sequence_order":2,"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\", \"comparator\": \"Baseline/placebo comparison\", \"endpoint\": \"Separate raclopride PET measurements after oral modafinil supported increased extracellular dopamine; radiotracer displacement is an indirect indicator, not chemical sampling.\", \"effect_direction\": \"increase\", \"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, 200 or 400 mg oral exposure.","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. The complete source passage retains qualifications; unspecified doses/timing have not been extracted here. No clinical efficacy, nutrient deficiency or unique molecular mediation is inferred.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Separate raclopride PET measurements after oral modafinil supported increased extracellular dopamine; radiotracer displacement is an indirect indicator, not chemical sampling.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Effects of modafinil on dopamine and dopamine transporters in the male human brain: clinical implications. | 2009 | DOI 10.1001/jama.2009.351 | PMID 19293415 | https://pubmed.ncbi.nlm.nih.gov/19293415/","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 36-36; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"ddb08f94-3c81-5170-95ea-e198fd270a8a","evidence_kind":"source_excerpt","locator":"Lines 36-36","start_line":36,"end_line":36,"excerpt":"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/)","model_system":"Human PET, ten healthy men, 200 or 400 mg oral exposure.","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. Not a verbatim quotation from a primary paper.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"17a64928-eaa2-5117-ba4f-52dcbdf9cc9e","stable_key":"import-6660bba2-4fa0-590a-bf52-9803a24bea9f","title":"Modafinil: detailed mechanisms of action (reviewed 3 October 2026)","document_type":"imported_text","citation_label":"Original AI-assisted review of primary studies and, where relevant, official regulatory records. Access level is retained per claim. Corrections, null results and unresolved questions remain explicit. Not publisher full text or independent replication.","file_path":"","sha256":"006008cb4cfd183dd3b0846d3abc66c8ebf40cf1b6bd1f0bcdb4f4d937a8e115","revision_id":"c85b3e2e-c18a-59fc-9e79-5c375e64d119","review_status":"source_recorded","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}