{"id":"37c0a543-1f9a-574a-bd73-62e24be9bdd3","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-rat-dopamine-transients","predicate":"when_depleted_reduces","statement":"Combined phenylalanine/tyrosine depletion decreased dopamine-transient frequency without decreasing transient amplitude in freely moving rats.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"52495362-1b2f-52a9-94d5-52c8c725f588","mechanism_event_label":"Less precursor can change release dynamics without simply emptying all dopamine stores.","subject":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"object":{"id":"efd6b709-d381-5e87-b162-2f3a339b66bc","slug":"rat-nac-dopamine-transient-frequency","display_name":"Rat nucleus-accumbens dopamine transient frequency","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"52495362-1b2f-52a9-94d5-52c8c725f588","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-rat-dopamine-transients-event","event_type":"observed_relationship","label":"Less precursor can change release dynamics without simply emptying all dopamine stores.","description":"Combined phenylalanine/tyrosine depletion decreased dopamine-transient frequency without decreasing transient amplitude in freely moving rats.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"efd6b709-d381-5e87-b162-2f3a339b66bc","slug":"rat-nac-dopamine-transient-frequency","display_name":"Rat nucleus-accumbens dopamine transient frequency","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"9cca6209-0603-5ab7-96ad-2f3ae4b772d2","slug":"dopamine","display_name":"Dopamine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"190407ad-0219-54b5-b05f-7c75f3895ca6","slug":"l-phenylalanine","display_name":"L-Phenylalanine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Fast-scan cyclic voltammetry in a separate rat group from the tissue-content experiment.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The release endpoint is not a direct human measurement; the corrected norepinephrine endpoint is excluded. Correction record: The 2018 correction (PMID 30094500) reports an error in norepinephrine standard concentrations used for HPLC calibration. The correction abstract was inspected, but full notice content was unavailable; its complete quantitative scope remains unverified. This collection uses the tyrosine depletion and dopamine-transient findings and does not reuse the original norepinephrine concentration result. https://pubmed.ncbi.nlm.nih.gov/30094500/","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Less precursor can change release dynamics without simply emptying all dopamine stores.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Acute phenylalanine/tyrosine depletion of phasic dopamine in the rat brain. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26944052/ · DOI 10.1007/s00213-016-4259-0","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"2df66de7-56ff-56f0-bccd-157c85edb84c","evidence_kind":"source_excerpt","locator":"Lines 388-394","start_line":388,"end_line":394,"excerpt":"## l-tyrosine-rat-dopamine-transients\nLess precursor can change release dynamics without simply emptying all dopamine stores.\nCombined phenylalanine/tyrosine depletion decreased dopamine-transient frequency without decreasing transient amplitude in freely moving rats.\nModel: Fast-scan cyclic voltammetry in a separate rat group from the tissue-content experiment.\nLimitations: The release endpoint is not a direct human measurement; the corrected norepinephrine endpoint is excluded. Correction record: The 2018 correction (PMID 30094500) reports an error in norepinephrine standard concentrations used for HPLC calibration. The correction abstract was inspected, but full notice content was unavailable; its complete quantitative scope remains unverified. This collection uses the tyrosine depletion and dopamine-transient findings and does not reuse the original norepinephrine concentration result. https://pubmed.ncbi.nlm.nih.gov/30094500/\nEvidence access: Primary abstract\nAcute phenylalanine/tyrosine depletion of phasic dopamine in the rat brain. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26944052/ · DOI 10.1007/s00213-016-4259-0","model_system":"Fast-scan cyclic voltammetry in a separate rat group from the tissue-content experiment.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"12917df2-c6e0-5b61-850f-dbff6d4b4d30","stable_key":"import-63ce713e-6aea-59f6-9896-ca30e010b2ce","title":"L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"7777f4440a8bfb14a04ff73e73392ccc45d8ee89f7853ecbcc0027d6f563b8a0","revision_id":"e1206111-3a75-5809-b8e9-231ff809ff1e","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}