- 作者：Limin Sun ; Nazareth Castellanos ; Christine Gr眉tzner ; Dagmar Koethe ; Davide Rivolta ; Michael Wibral ; Laura Kranaster ; Wolf Singer ; Markus F. Leweke ; Peter J. Uhlhaas
- 关键词：Schizophrenia ; High-frequency oscillations ; Perceptual organization ; Neural synchrony ; First-episode ; MEG
- 刊名：Schizophrenia Research
- 出版年：November, 2013
- 年：2013
- 卷：150
- 期：2-3
- 页码：519-525
- 全文大小：769 K
Introduction
High-frequency oscillations are important for sensory processing and dysfunctions in the amplitude and synchrony of beta- and gamma-band oscillations have been demonstrated in schizophrenia (ScZ). However, the presence of aberrant high-frequency oscillations in first-episode (FE), medication-naive patients during sensory processing is unclear.Methods
Magnetoencephalographic (MEG) data were recorded from 15 never-medicated, FE-ScZ patients and 20 matched healthy controls during the perception of Mooney faces. MEG data were analysed for spectral power and single-sensor phase-locking in the beta (13-25 Hz) and gamma- (25-140 Hz) frequency range.
Results
FE-ScZ patients were characterized by significantly impaired sensory processing as indicated by a reduced discrimination index (A鈥?. Impaired behavioural performance in ScZ-patients was accompanied by decreased spectral power in the high- (60-120 Hz) gamma-band range. In contrast, oscillations in the lower (25-60 Hz) gamma-band were largely intact and beta-band oscillations were increased. Analysis of cross-frequency coupling showed a reduced correlation between 60 and 120 Hz amplitude values and beta-band power in FE-ScZ-patients relative to controls.
Discussion
Our findings show that impaired sensory processing in medication-naive, FE-schizophrenia is related to a dysregulation of neural oscillations which involves both an impairment in the generation of high gamma-band activity as well as a failure to downregulate task-irrelevant beta-band activity. Because of the interrelationship of these dysfunctions and the role of inhibitory networks in the shaping of high-frequency activity, aberrant neural oscillations in FE-schizophrenia may be linked to dysfunctions in the excitation-inhibition (E/I)-balance.