title: GABA concentration in superior temporal sulcus predicts gamma power and perception in the sound-induced flash illusion.
abstract: In everyday life we are confronted with inputs of multisensory stimuli that need to be integrated across our senses. Individuals vary considerably in how they integrate multisensory information, yet the neurochemical foundations underlying this variability are not well understood. Neural oscillations, especially in the gamma band (>30Hz) play an important role in multisensory processing. Furthermore, gamma-aminobutyric acid (GABA) neurotransmission contributes to the generation of gamma band oscillations (GBO), which can be sustained by activation of metabotropic glutamate receptors. Hence, differences in the GABA and glutamate systems might contribute to individual differences in multisensory processing. In this combined magnetic resonance spectroscopy and electroencephalography study, we examined the relationships between GABA and glutamate concentrations in the superior temporal sulcus (STS), source localized GBO, and illusion rate in the sound-induced flash illusion (SIFI). In 39 human volunteers we found robust relationships between GABA concentration, GBO power, and the SIFI perception rate (r-values=0.44 to 0.53). The correlation between GBO power and SIFI perception rate was about twofold higher when the modulating influence of the GABA level was included in the analysis as compared to when it was excluded. No significant effects were obtained for glutamate concentration. Our study suggests that the GABA level shapes individual differences in audiovisual perception through its modulating influence on GBO. GABA neurotransmission could be a promising target for treatment interventions of multisensory processing deficits in clinical populations, such as schizophrenia or autism.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Große Hamburger Straße 5-11, 10115 Berlin, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Balz
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Große Hamburger Straße 5-11, 10115 Berlin, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Keil
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Große Hamburger Straße 5-11, 10115 Berlin, Germany.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Roa Romero
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Mekle
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Schubert
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Semiha
authors.initials: S
authors.lastname: Aydin
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Ittermann
authors.affiliation: Department of Psychiatry and Psychotherapy, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Große Hamburger Straße 5-11, 10115 Berlin, Germany. Electronic address: daniel.senkowski@charite.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Senkowski
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009903:Optical Illusions / Q000502:physiology*; D010775:Photic Stimulation; D013702:Temporal Lobe / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D005680:gamma-Aminobutyric Acid
keywords: Electroencephalography; Gamma-aminobutyric acid; Glutamate; Magnetic resonance spectroscopy; Multisensory; Oscillatory activity