TY - JOUR
T1 - Evidence for dysregulated high-frequency oscillations during sensory processing in medication-naïve, first episode schizophrenia
AU - Sun, Limin
AU - Castellanos, Nazareth
AU - Grützner, Christine
AU - Koethe, Dagmar
AU - Rivolta, Davide
AU - Wibral, Michael
AU - Kranaster, Laura
AU - Singer, Wolf
AU - Leweke, Markus F.
AU - Uhlhaas, Peter J.
PY - 2013/11
Y1 - 2013/11
N2 - 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'). 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.
AB - 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'). 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.
KW - First-episode
KW - High-frequency oscillations
KW - MEG
KW - Neural synchrony
KW - Perceptual organization
KW - Schizophrenia
UR - http://www.scopus.com/inward/record.url?scp=84886287924&partnerID=8YFLogxK
U2 - 10.1016/j.schres.2013.08.023
DO - 10.1016/j.schres.2013.08.023
M3 - Article
C2 - 24016727
AN - SCOPUS:84886287924
SN - 0920-9964
VL - 150
SP - 519
EP - 525
JO - Schizophrenia Research
JF - Schizophrenia Research
IS - 2-3
ER -