title: Association of EEG coherence and an exonic GABA(B)R1 gene polymorphism.
abstract: The GABA(B) receptor 1 gene is mapped to chromosome 6p21.3 within the HLA class I region close to the HLA-F gene. Susceptibility loci for epilepsy and schizophrenia have been mapped in this region. Based on pharmacological evidence, it has been suggested that GABA(B) receptors may play a crucial role in the synchronization of EEG oscillations, which in turn can be abnormal in neuropsychiatric disorders. In the present study, the hypothesis was tested, whether three exonic variants of the gene encoding the human GABA(B) receptor (GABA(B)R1) modify cortical synchronization measured as scalp-recorded EEG-coherence. Two principal components of EEG coherence (frontal coherence, parietotemporal coherence) were investigated in 104 healthy subjects during three conditions: resting EEG, activated EEG, and event-related EEG. No significant associations were found between the frontal coherence component and any polymorphism or between the parietotemporal coherence component and the exon 1a1 polymorphism. However, parietotemporal coherence showed statistically highly significant associations across all three experimental conditions with exon 7 and trend associations with exon 11. The results provide evidence that the translated polymorphism of exon 7 may be functionally meaningful and impact cortical EEG oscillations. Since variations of EEG coherence have been described for several neuropsychiatric disorders, the present association should be tested in clinical samples using EEG coherence as an intermediate phenotype.
authors.affiliation: Department of Psychiatry, University Hospital Benjamin Franklin, Free University of Berlin, Berlin, Germany. wintereg@intra.nimh.nih.gov
authors.forename: Georg
authors.initials: G
authors.lastname: Winterer
authors.forename: Michael
authors.initials: M
authors.lastname: Smolka
authors.forename: Jerzy
authors.initials: J
authors.lastname: Samochowiec
authors.forename: Mario
authors.initials: M
authors.lastname: Ziller
authors.forename: Richard
authors.initials: R
authors.lastname: Mahlberg
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Rommelspacher
authors.forename: Werner M
authors.initials: WM
authors.lastname: Herrmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Sander
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003344:Cortical Synchronization; D004569:Electroencephalography; D005091:Exons; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic; D018080:Receptors, GABA-B / Q000235:genetics*
chemical_list: D018080:Receptors, GABA-B