Direct evidence that acutely enhancing serotonin with the selective serotonin reuptake inhibitor citalopram modulates the loudness dependence of the auditory evoked potential (LDAEP) marker of central serotonin function

Authors

  • Pradeep J. Nathan,

    Corresponding author
    1. Behavioural Neuroscience Laboratory, Department of Physiology, Monash Centre for Brain and Behaviour, Monash University, Melbourne, Australia
    • Behavioural Neuroscience Laboratory, Department of Physiology, Monash Centre for Brain and Behaviour, PO Box 13F, Monash University, Victoria, 3800.
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  • Rebecca Segrave,

    1. Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia
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  • K. Luan Phan,

    1. Behavioural Neuroscience Laboratory, Department of Physiology, Monash Centre for Brain and Behaviour, Monash University, Melbourne, Australia
    2. Clinical Neuroscience and Psychopharmacology Research Unit, Department of Psychiatry, Biological Sciences Division and the Pritzker School of Medicine, The University of Chicago, Chicago, Illinois, USA
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  • Barry O'Neill,

    1. Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia
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  • Rodney J. Croft

    1. Behavioural Neuroscience Laboratory, Department of Physiology, Monash Centre for Brain and Behaviour, Monash University, Melbourne, Australia
    2. Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia
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Abstract

The loudness dependence of the auditory evoked potential (LDAEP) has been suggested as a reliable measure of central serotonin function in humans. The most convincing evidence for a direct relationship between serotonergic function and LDAEP to date has come from animal studies, while evidence in humans has been circumstantial and inconsistent. In the current study, we examine the direct effect of serotonergic modulation with the selective serotonin reuptake inhibitor (SSRI) citalopram on the LDAEP. The study was a double-blind placebo controlled design in which healthy participants were tested under two acute treatment conditions: placebo and citalopram (20 mg). Enhancement of serotonin function with citalopram in comparison to placebo decreased the slope of the LDAEP (i.e. weaker LDAEP). The findings provide direct evidence in humans, of a relationship between central serotonin function and the LDAEP, supporting findings previously observed in animals and clinical populations. Together the results provide further support for the validity of the LDAEP as a non-invasive in vivo measure of central serotonin function in humans. Copyright © 2005 John Wiley & Sons, Ltd.

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