title: Cognitive function is related to fronto-striatal serotonin transporter levels--a brain PET study in young healthy subjects.
abstract: BACKGROUND
  Pharmacological manipulation of serotonergic neurotransmission in healthy volunteers impacts on cognitive test performance. Specifically, markers of serotonin function are associated with attention and executive functioning, long-term memory, and general cognitive ability. The serotonin transporter (SERT) protein is a key regulator in the serotonin system. We hypothesized that higher performance on tests sensitive to serotonin would be associated with higher SERT levels in specific fronto-striatal brain regions.
  
  
  METHODS
  Thirty-two healthy subjects (25 males, mean age 26.0 years, range 19-37) underwent positron emission tomography using the SERT ligand [(11)C]DASB. Subjects underwent the following tests: Stroop Color Word Test, Trail Making Test B, Rey's Auditory Verbal Learning Test and Complex Figure Test, logical reasoning subtest from Intelligenz-Struktur-Test 2000 R, and a Danish version of National Adult Reading Test.
  
  
  RESULTS
  We found positive associations between performance on the Stroop Color Word Test and right-sided dorsolateral prefrontal SERT binding (R(2) = 0.12, p = 0.048). Furthermore, scores of logical reasoning (correlating with IQ) and educational level associated positively with SERT binding in the caudate, most prominent on the left side (logical reasoning: R(2) = 0.34, p = 0.0026 (left), R(2) = 0.2, p = 0.022 (right), educational level: R(2) = 0.19, p = 0.012 (left), R(2) = 0.15, p = 0.027 (right)). Scores of logical reasoning also associated with left-sided ventrolateral prefrontal cortex (R(2) = 0.24, p = 0.014). There were no significant associations between SERT binding and tests of long-term episodic memory.
  
  
  CONCLUSIONS
  The results imply that in healthy subjects, high SERT binding in fronto-striatal regions is associated with better performance on tasks involving executive function and logical reasoning.
authors.affiliation: The Neuroscience Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Karine
authors.initials: K
authors.lastname: Madsen
authors.forename: David
authors.initials: D
authors.lastname: Erritzoe
authors.forename: Erik Lykke
authors.initials: EL
authors.lastname: Mortensen
authors.forename: Anders
authors.initials: A
authors.lastname: Gade
authors.forename: Jacob
authors.initials: J
authors.lastname: Madsen
authors.forename: William
authors.initials: W
authors.lastname: Baaré
authors.forename: Gitte M
authors.initials: GM
authors.lastname: Knudsen
authors.forename: Steen G
authors.initials: SG
authors.lastname: Hasselbalch
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D003342:Corpus Striatum / Q000378:metabolism; D056344:Executive Function / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism; D006801:Humans; D008128:Logic; D008297:Male; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D057190:Stroop Test; D055815:Young Adult
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins