Original Investigation

Psychopharmacology

, Volume 221, Issue 3, pp 389-396

Examination of the effect of acute levodopa administration on the loudness dependence of auditory evoked potentials (LDAEP) in humans

  • K. HitzAffiliated withDepartment of General Social Psychiatry, University of Zurich
  • , K. HeekerenAffiliated withDepartment of General Social Psychiatry, University of Zurich
  • , C. ObermannAffiliated withDepartment of General Social Psychiatry, University of Zurich
  • , T. HuberAffiliated withInternal Medicine, Psychiatric University Hospital Zurich
  • , G. JuckelAffiliated withDepartment of Psychiatry, Ruhr-University Bochum
  • , W. KawohlAffiliated withDepartment of General Social Psychiatry, University of ZurichPsychiatric University Hospital Zurich Email author 

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Rationale

The loudness dependence of the auditory evoked potential (LDAEP) is considered a noninvasive in vivo marker of central serotonergic functioning in humans. Nevertheless, results of genetic association studies point towards a modulation of this biomarker by dopaminergic neurotransmission.

Objective

We examined the effect of dopaminergic modulation on the LDAEP using L-3,4-dihydroxyphenylalanine (levodopa)/benserazide (Madopar®) as a challenge agent in healthy volunteers.

Methods

A double-blind placebo-controlled challenge design was chosen. Forty-two healthy participants (21 females and 21 males) underwent two LDAEP measurements, following a baseline LDAEP measurement either placebo or levodopa (levodopa 200 mg/benserazide 50 mg) were given orally. Changes in the amplitude and dipole source activity of the N1/P2 intensities (60, 70, 80, 90, and 100 dB) were analyzed.

Results

The participants of neither the levodopa nor the placebo group showed any significant LDAEP alterations compared to the baseline measurement. The test–retest reliability (Cronbachs Alpha) between baseline and intervention was 0.966 in the verum group and 0.759 in the placebo group, respectively.

Conclusions

The administration of levodopa showed no effect on the LDAEP. These findings are in line with other trials using dopamine receptor agonists.

Keywords

Dopamine Loudness dependence auditory evoked potentials (LDAEP) Levodopa Primary auditory cortex Serotonin