Serotonergic functioning as measured by the loudness dependence of auditory evoked potentials is related to a haplotype in the brain-derived neurotrophic factor (BDNF) gene.
OBJECTIVE
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 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
Ninety five healthy subjects (41 males, 54 females) received electrophysiological recording of LDAEP and blood drawing for BDNF genotyping. Three BDNF markers (including the single nucleotide polymorphism rs6265(Val66Met)) were analyzed.


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 as well as for the vertex electrode (Cz).


CONCLUSIONS
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.
Juckel
Georg
G
Department of Psychiatry, Ruhr University, 44791 Bochum, Germany. Georg.Juckel@wkp-lwl.org
Schumacher
Christiane
C
Giegling
Ina
I
Assion
Hans-Jörg
HJ
Mavrogiorgou
Paraskevi
P
Pogarell
Oliver
O
Mulert
Christoph
C
Hegerl
Ulrich
U
Norra
Christine
C
Rujescu
Dan
D
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000368:Aged; D001303:Auditory Cortex / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood / Q000235:genetics*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000235:genetics*; D005260:Female; D007839:Functional Laterality; D005787:Gene Frequency; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium / Q000502:physiology; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011571:Psychoacoustics; D012701:Serotonin / Q000378:metabolism*; D055815:Young Adult
D019208:Brain-Derived Neurotrophic Factor; D012701:Serotonin