title: Exogenous dopamine reduces GABA receptor availability in the human brain.
abstract: While it has recently been shown that dopamine release stimulates conscious self-monitoring through the generation of gamma oscillations in medial prefrontal/anterior cingulate cortex, and that the GABAergic system is effective in producing such oscillations, interaction of the two transmitter systems has not been demonstrated in humans. We here hypothesize that dopamine challenge stimulates the GABA system directly in the medial prefrontal/anterior cingulate region in the human brain.
  
  
  
  Positron emission tomography (PET) with the GABA receptor α1/α5 subtype ligand [(11)C] Ro15-4513 was used to detect changes in GABA receptor availability after clinical oral doses of levodopa in a double blind controlled study.
  
  
  
  We here provide the first direct evidence for such coupling in the cerebral cortex, in particular in the medial prefrontal anterior cingulate region, by showing that exogenous dopamine decreases [(11)C] Ro15-4513 binding widely in the human brain compatible with a fall in α1 subtype availability in GABA complexes due to increased GABA activity.
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: Hans C
authors.initials: HC
authors.lastname: Lou
authors.affiliation: Dept. Ophtalmology Rigshospitalet Glostrup Copenhagen University Denmark.
authors.forename: Astrid
authors.initials: A
authors.lastname: Rosenstand
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: David J
authors.initials: DJ
authors.lastname: Brooks
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: Dirk
authors.initials: D
authors.lastname: Bender
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Jakobsen
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: Jakob U
authors.initials: JU
authors.lastname: Blicher
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: Kim V
authors.initials: KV
authors.lastname: Hansen
authors.affiliation: CFIN and Pet Center Aarhus University Norregade 44 8000 Aarhus Denmark.
authors.forename: Arne
authors.initials: A
authors.lastname: Møller
mesh_terms: D000328:Adult; D001386:Azides / Q000378:metabolism; D001569:Benzodiazepines / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism*; D002250:Carbon Radioisotopes; D015259:Dopamine Agents / Q000494:pharmacology*; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007980:Levodopa / Q000494:pharmacology*; D008024:Ligands; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D018079:Receptors, GABA / Q000378:metabolism*; D055815:Young Adult
chemical_list: D001386:Azides; D002250:Carbon Radioisotopes; D015259:Dopamine Agents; D008024:Ligands; D018079:Receptors, GABA; D001569:Benzodiazepines; D007980:Levodopa; C042957:Ro 15-4513
keywords: Dopamine; GABA; insula; medial prefrontal/anterior cingulate; self‐awareness