Auditory-evoked potentials as indicator of brain serotonergic activity - First evidence in behaving cats

Georg Juckel, Márk Molnár, Ulrich Hegerl, Valéria Csépe, George Karmos

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Due to the increasing importance of the central serotonergic neurotransmission for pathogenetic concepts and as a target of pharmacotherapeutic interventions in psychiatry, reliable indicators of this system are needed. Several findings from basic and clinical research suggest that the stimulus intensity dependence of auditory evoked potentials (AEP) may be such an indicator of behaviorally relevant aspects of serotonergic activity (Hegerl and Juckel 1993, Biol Psychiatry 33:173-187.). In order to study this relationship more directly, epidural recordings over the primary and secondary auditory cortex were conducted in chronically implanted cats under intravenous (i.v.) administration of drugs influencing the serotonergic and other modulatory systems (8-OH-DPAT: m-CPP, ketanserin, DOI, apomorphine, atropine clonidine). The intensity dependence of the cat AEP component with the highest functional similarity to this of the N1/P2-component in humans was significantly changed by influencing 5-HT(1a) and 5-HT2 receptors, but not 5-HT(1c) receptors. This serotonergic modulation of the intensity dependence was only found for the primary auditory cortex which corresponds to the known different innervation of the primary and secondary auditory cortex by serotonergic fibers. Our study supports the idea that the intensity dependence of AEP could be a valuable indicator of brain serotonergic activity; however this indicator seems to be of relative specificity because at least cholinergic effects on the intensity dependence were also observed.

Original languageEnglish
Pages (from-to)1181-1195
Number of pages15
JournalBiological Psychiatry
Issue number12
Publication statusPublished - Jun 15 1997



  • Auditory evoked potentials
  • Augmenting/reducing
  • Serotonin
  • auditory cortex

ASJC Scopus subject areas

  • Biological Psychiatry

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