title: Acute dopamine and/or serotonin depletion does not modulate mismatch negativity (MMN) in healthy human participants.
abstract: BACKGROUND
  Schizophrenia is commonly associated with impairments in pre-attentive change detection, as represented by reduced mismatch negativity (MMN). While the neurochemical basis of MMN has been linked to N-methyl-D: -aspartic acid (NMDA) receptor function, the roles of the dopaminergic and/or the serotonergic systems are not fully explored in humans.
  
  
  OBJECTIVE
  The aim of the present study was to investigate the effects of acutely depleting dopamine (DA) and serotonin (5-hydroxytryptamine, 5-HT) alone or simultaneously by depleting their amino acid precursors on MMN in healthy participants.
  
  
  METHODS
  Sixteen healthy male subjects participated in a double-blind, placebo-controlled, cross-over design in which each subject's duration MMN was assessed under four acute treatment conditions separated by a 5-day washout period: balanced amino acid control (no depletion), tyrosine/phenylalanine depletion (to reduce DA neurotransmission), tryptophan depletion (to reduce 5-HT neurotransmission) and tryptophan/tyrosine/phenylalanine depletion (to reduce DA and 5-HT neurotransmission simultaneously).
  
  
  RESULTS
  Acute depletion of either DA and 5-HT alone or simultaneously had no effect on MMN.
  
  
  CONCLUSIONS
  These findings suggest that modulation of the dopaminergic and serotonergic systems acutely does not lead to changes in MMN.
authors.affiliation: Brain Sciences Institute, Faculty of Life and Social Sciences, Swinburne University of Technology, P.O. Box 218, John Street Hawthorn, 3122, Melbourne, VIC, Australia. smleung@groupwise.swin.edu.au
authors.forename: Sumie
authors.initials: S
authors.lastname: Leung
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Croft
authors.forename: Valérie
authors.initials: V
authors.lastname: Guille
authors.forename: Kirsty
authors.initials: K
authors.lastname: Scholes
authors.forename: Barry V
authors.initials: BV
authors.lastname: O'Neill
authors.forename: K Luan
authors.initials: KL
authors.lastname: Phan
authors.forename: Pradeep J
authors.initials: PJ
authors.lastname: Nathan
mesh_terms: D000328:Adult; D003265:Contingent Negative Variation; D018592:Cross-Over Studies; D004298:Dopamine / Q000172:deficiency*; D004311:Double-Blind Method; D004569:Electroencephalography; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000378:metabolism*; D010649:Phenylalanine / Q000172:deficiency; D011930:Reaction Time; D012701:Serotonin / Q000172:deficiency*; D013997:Time Factors; D014364:Tryptophan / Q000172:deficiency; D014443:Tyrosine / Q000172:deficiency; D055815:Young Adult
chemical_list: D012701:Serotonin; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D004298:Dopamine