Gamma oscillations in schizophrenia: Mechanisms and clinical significance

Brain oscillations are increasingly used for understanding complex psychiatric disorders. Gamma (30-50 Hz) oscillations have warranted special attention due to their omnipresence in cognitive tasks. For patients with schizophrenia (SCZ), a disease associated with poor cognition, abnormal gamma oscillations have been reported in many experimental paradigms. The goal of this paper is to review the literature on gamma oscillations in SCZ. The review is structured into four sections. First, the functional role, neurobiology, and analysis of brain oscillations, especially gamma oscillations will be outlined. Second, the neurobiological abnormalities of SCZ in relation to gamma oscillations will be reviewed. Third, selected paradigms for investigating irregular gamma oscillations in SCZ will be discussed in detail. Finally, a discussion on the limitations of current findings and potential future research directions will be provided. The reviewed evidence suggests that gamma oscillations are disrupted in SCZ and could account for cognitive disturbances in this disorder. With additional analysis and experimentation, these indices may ultimately serve as endophenotypes that facilitate the development of etiologically based diagnostic methods, foster early identification and treatment, and advance our understanding of the complex genetic mechanisms involved in this disorder. (C) 2011 Elsevier B.V. All rights reserved.