Klinische Neurophysiologie 2010; 41 - ID70
DOI: 10.1055/s-0030-1250899

Impact of a haplotype (Val66Met) in the brain derived neurotrophic factor (BDNF) gene on serotonergic neurotransmission as reflected by the loudness dependence of auditory evoked potentials

C Norra 1, C Schumacher 1, I Giegling 2, H Assion 1, P Mavrogiorgou 1, O Pogarell 2, C Mulert 2, U Hegerl 3, D Rujescu 2, G Juckel 1
  • 1Ruhr Universität Bochum, Psychiatrie und Psychotherapie, Bochum, Deutschland
  • 2LMU München, Psychiatrie, München, Deutschland
  • 3Universität Leipzig, Psychiatrie, Leipzig, Deutschland

Objectives: The serotonergic system plays an important pathophysiological role in various psychiatric disorders. Brain derived neurotrophic factor (BDNF) is involved in the differentiation and survival of serotonergic neurons. A previous study showed that low serum BDNF levels were associated with strong loudness dependence of auditory evoked potentials (LDAEP) as a reflection of low central nervous serotonergic activity. To evaluate the genetic basis of this relationship, we studied whether the LDAEP is correlated with genetic variants within the BDNF gene.

Methods: Auditory evoked potentials (AEP) of 95 healthy volunteers 41 males, 54 females) were recorded using multi-channel EEG. Bloods were taken for BDNF genotyping with analysis of three BDNF markers (including the single nucleotide polymorphism rs6265(Val66Met)).

Results: Haplotype analysis revealed stronger LDAEP values in carriers of the G(Val)-C-T [rs6265(Val66Met)-rs2030324-rs1491850] haplotype within the BDNF gene in comparison to other haplotype carriers. These findings were demonstrated for the LDAEP of both left and right primary auditory cortices (respectively tangential dipole sources) as well as for the vertex electrode (Cz). Findings on the single marker analysis corresponded to the haplotype results.

Discussion: Subjects with the BDNF haplotype G(Val)-C-T seem to be characterized by low serotonergic activity as well as possibly by low serum BDNF levels. These findings need replication in independent samples.