title: Dopamine receptor stimulation does not modulate the loudness dependence of the auditory evoked potential in humans.
abstract: BACKGROUND
  The Loudness Dependence of the Auditory Evoked Potential (LDAEP) has been suggested as a reliable measure of central serotonin function in humans; however, its specificity for the serotonin system remains a topic of debate, with possible modulation of this purported serotonin marker by other neurotransmitters, including dopamine.
  
  
  OBJECTIVE
  We examined the effect of dopaminergic modulation on the LDAEP using the D1/D2/D3 dopamine receptor agonist pergolide and the D2/D3 agonist bromocriptine.
  
  
  METHODS
  The study was a double-blind, placebo-controlled repeated-measures design in which healthy participants were tested under three acute treatment conditions: placebo, bromocriptine (2.5 mg), and pergolide (0.1 mg). Changes in the amplitude of the N1/P2 at intensities (60, 70, 80, 90, and 100 dB) were examined at C Z.
  
  
  RESULTS
  Acute stimulation of D1/D2/D3 receptors with pergolide and D2/D3 receptors with bromocriptine in comparison with placebo had no effect on the LDAEP.
  
  
  CONCLUSIONS
  These findings indicate that acute stimulation of dopamine D1, D2, and D3 receptors does not modulate the LDAEP in humans. Although the findings suggest that the LDAEP may not be modulated by acute changes in dopamine neurotransmission, further studies are needed to fully characterize its dopaminergic sensitivity.
authors.affiliation: Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia.
authors.forename: Barry V
authors.initials: BV
authors.lastname: O'Neill
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Croft
authors.forename: Sumie
authors.initials: S
authors.lastname: Leung
authors.forename: Valérie
authors.initials: V
authors.lastname: Guille
authors.forename: Matthew
authors.initials: M
authors.lastname: Galloway
authors.forename: K Luan
authors.initials: KL
authors.lastname: Phan
authors.forename: Pradeep J
authors.initials: PJ
authors.lastname: Nathan
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001971:Bromocriptine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology*; D004311:Double-Blind Method; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D006801:Humans; D008297:Male; D010479:Pergolide / Q000494:pharmacology; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism; D050637:Receptors, Dopamine D3 / Q000187:drug effects / Q000378:metabolism; D012016:Reference Values
chemical_list: D018491:Dopamine Agonists; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D010479:Pergolide; D001971:Bromocriptine