Dopamine receptor stimulation does not modulate the loudness dependence of the auditory evoked potential in humans

Abstract

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.

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

“…Assuming such an individual sensitivity exists, an examination of parameters influencing the LDAEP such as the COMT polymorphism would be interesting. Our result stands in line with other findings in the literature; O'Neill et al (O'Neill et al 2006(O'Neill et al , 2008b did not find any effect of acute dopamine receptor stimulation with pergolide or bromocriptine on the LDAEP. In the studies using dopamine receptor agonists and in our trial an iatrogenic condition as a state factor is used.…”

“…However, O'Neill et al (O'Neill et al 2006) could not find a significant effect on the LDAEP after dopaminergic stimulation of the D 1 /D 2 /D 3 receptors with pergolide and D 2 /D 3 receptors with bromocriptine. In another trial of the same study group, selective serotonin and dopamine depletion with greater than 80% plasma precursor depletion had no effect on the LDAEP (O'Neill et al 2008b).…”

“…After 8 h of fasting (Black and Mink 2000) in order to exclude proteinous inhibition of the enteral levodopa absorption, the participants arrived on the testing days at 8 o'clock in the morning and ate a low protein breakfast (bread with butter and jam, orange juice). In order to reduce the likelihood of any nausea following levodopa/benserazide intake, domperidone 20 mg was given orally (O'Neill et al 2006). Domperidone does not cross the blood/brain barrier and acts as a peripheral dopamine antagonist (O'Neill et al 2006).…”

“…In order to reduce the likelihood of any nausea following levodopa/benserazide intake, domperidone 20 mg was given orally (O'Neill et al 2006). Domperidone does not cross the blood/brain barrier and acts as a peripheral dopamine antagonist (O'Neill et al 2006). Afterwards, a baseline LDAEPrecording was performed.…”

“…Several findings cast some doubt over its sensitivity to changes in 5-HT functioning alone (Juckel et al , 1997O'Neill et al 2006;Pogarell et al 2004;Uhl et al 2006). An association between 5-HT (SERT) and dopamine (DAT) transporter availability and the interindividual LDAEP has been found in a [123I]beta-CIT single-photon emission computed tomography (SPECT) study (Pogarell et al 2004).…”