Gamma Band Oscillations Reveal Neural Network Cortical Coherence Dysfunction in Schizophrenia Patients

Light, Gregory A.; Hsu, Jung Lung; Hsieh, Ming H.; Meyer-Gomes, Katrin; Sprock, Joyce; Swerdlow, Neal R.; Braff, David L.

doi:10.1016/j.biopsych.2006.03.055

Cited by 399 publications

(356 citation statements)

References 107 publications

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“…Hong et al (2004) demonstrated a similar reduction in evoked potential amplitude to click trains (476 ms length) in un-medicated first degree relatives of schizophrenic patients, but failed to replicate the reduction in the medicated patients themselves. Most recently, Light et al (2006) report a reduction in 40 Hz evoked power and inter-trial phase coherence at electrode site Fz in patients with schizophrenia using a 500 ms click train stimulus similar to that of Kwon and colleagues.…”

Section: Introductionmentioning

confidence: 73%

Cortical source estimates of gamma band amplitude and phase are different in schizophrenia

et al. 2008

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Reductions in gamma band phase synchrony and evoked power have been reported in schizophrenic subjects in response to auditory stimuli. These results have been observed in the EEG at one or two electrode sites. We wished to extend these results using magnetic field data to estimate the responses at the neural generators themselves in each hemisphere. Whole head magnetoencephalographic (MEG) recordings were used to estimate the phase and amplitude behavior of sources in primary auditory cortex in both hemispheres of schizophrenic and comparison subjects. Both ipsi-and contralateral cases were evaluated using a driving (40 Hz modulated 1 kHz carrier) and a non-driving (1 kHz tone) stimulus. We used source space projection (SSP) to collapse the magnetic field data into estimates of the time course of source strengths in individual trials. Complex wavelet based timefrequency decomposition was used to compute inter-trial phase locking factor (PLF), and mean evoked and induced amplitude for each cortical generator. Schizophrenic subjects showed reduced SSP PLF and evoked source strength for contra-lateral generators responding to the driving stimulus in both hemispheres. For the pure tone stimulus, only the left hemisphere PLF's in the transient window were reduced. In contrast, subjects with schizophrenia exhibited higher induced 40 Hz power to both stimulus types, consistent with the reduced PLF findings. The method of SSP combined with wavelet based complex demodulation produces a significant improvement in signal-to-noise ratio, and directly estimates the activity of the cortical generators responsible for gamma band auditory MEG evoked fields. Schizophrenic subjects exhibit significant impairment of generation and phase locking of this activity in auditory cortex, suggesting an impairment of GABA-ergic inhibitory interneuronal modulation of pyramidal cell activity.

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Section: Introductionmentioning

confidence: 73%

Cortical source estimates of gamma band amplitude and phase are different in schizophrenia

et al. 2008

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“…Previous studies using a similar click train paradigms (Hong et al 2004;Kwon et al 1999;Light et al 2006) do not confirm an increase in 20-Hz response to 40-Hz drive in the schizophrenic subjects, although Kwon et al does seem to show presence of such a signal but without statistical significance. Our modeling points to several reasons that this may be the case.…”

Section: Modeling Suggests Reasons That Schizophrenic Enhanced 20-hz mentioning

confidence: 79%

“…This may indicate that lower volume click trains will be more apt to expose 20-Hz behavior. Indeed one previous study (Light et al 2006 Figure 17 shows two individual trials of the GENESIS schizophrenic network with 40-Hz drive for a fixed connectivity. The top trace shows a network that has a decreased response to first, third, fifth, etc pulses from the drive, whereas the bottom trace shows a response that is instead least responsive to the second, fourth, sixth, etc inputs.…”

Section: Even In the Presence Of Extended Ipscs Strong Drive Can Eramentioning

confidence: 91%

Modeling Gaba Alterations in Schizophrenia: A Link Between Impaired Inhibition and Altered Gamma and Beta Range Auditory Entrainment

Vierling-Claassen¹,

Siekmeier²,

Stufflebeam³

2008

Schizophrenia Research

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Vierling-Claassen D, Siekmeier P, Stufflebeam S, Kopell N. Modeling GABA alterations in schizophrenia: a link between impaired inhibition and altered gamma and beta range auditory entrainment. J Neurophysiol 99: 2656 -2671, 2008. First published February 20, 2008 doi:10.1152/jn.00870.2007. The disorganized symptoms of schizophrenia, including severely disordered thought patterns, may be indicative of a problem with the construction and maintenance of cell assemblies during sensory processing and attention. The gamma and beta frequency bands (15-70 Hz) are believed relevant to such processing. This paper addresses the results of an experimental examination of the cortical response of 12 schizophrenia patients and 12 control subjects when presented with auditory click-train stimuli in the gamma/beta frequency band during measurement using magnetoencephalography (MEG), as well as earlier work by Kwon et al. These data indicate that control subjects show an increased 40-Hz response to both 20-and 40-Hz stimulation as compared with patients, whereas schizophrenic subjects show a preference for 20-Hz response to the same driving frequencies. In this work, two computational models of the auditory cortex are constructed based on postmortem studies that indicate cortical interneurons in schizophrenic subjects have decreased GAT-1 (a GABA transporter) and GAD 67 (1 of 2 enzymes responsible for GABA synthesis). The models transition from control to schizophrenic frequency response when an extended inhibitory decay time is introduced; this change captures a possible effect of these GABA alterations. Modeling gamma/beta range auditory entrainment in schizophrenia provides insight into how biophysical mechanisms can impact cognitive function. In addition, the study of dynamics that underlie auditory entrainment in schizophrenia may contribute to the understanding of how gamma and beta rhythms impact cognition in general.

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“…Most of these studies have employed low-level perceptual processing tasks, finding impaired evoked gamma power during a visual backward-masking task (Wynn et al, 2005), decreased evoked gamma power (Haig et al, 2000;Symond et al, 2005) and synchrony (Slewa-Younan et al, 2004;Symond et al, 2005) in auditory oddball paradigms, decreased evoked gamma power and synchrony in auditory steady-state potential paradigms using click-train stimuli (Kwon et al, 1999;Light et al, 2006) or sustained tones (Brenner et al, 2003), and decreased gamma phase-locking, observed in visual (Spencer et al, 2008a) and auditory oddball tasks , with auditory tones (Teale et al, 2008;Krishnan et al, 2009), and immediately before spontaneous movement (Staykova et al, 2008). Impaired evoked gamma activity has also been found in response to transcranial magnetic stimulation (Ferrarelli et al, 2008), in association with sensory gating deficits in schizophrenia (Hong et al, 2004a), and in the unaffected relatives of schizophrenia patients (Hong et al, 2004b).…”

Section: Introductionmentioning

confidence: 99%

Gamma Oscillatory Power is Impaired During Cognitive Control Independent of Medication Status in First-Episode Schizophrenia

Minzenberg

Firl

Yoon

et al. 2010

Neuropsychopharmacol

217

169

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Schizophrenia is characterized by impaired cognitive control associated with prefrontal cortex dysfunction, but the underlying pathophysioloical mechanisms remain unknown. Higher cognitive processes are associated with cortical oscillations in the gamma range, which are also impaired in chronic schizophrenia. We tested whether cognitive control-related gamma deficits are observed in firstepisode patients, and whether they are associated with antipsychotic medication exposure. Fifty-three first-episode schizophrenia patients (21 without antipsychotic medication treatment) and 29 healthy control subjects underwent electroencephalography (EEG) during performance of a preparatory cognitive control task (preparing to overcome prepotency or POP task). The first-episode schizophrenia patient group was impaired (relative to the control group) on task performance and on delay-period gamma power at each of the three subgroups of frontal electrodes. The unmedicated patient subgroup was similarly impaired compared with controls, and was not different on these measures compared with the medicated patient subgroup. In contrast, delay-period theta power was not impaired in the full patient group nor in the unmedicated patient subgroup. Impaired cognitive control-related gamma cortical oscillatory activity is present at the first psychotic episode in schizophrenia, and is independent of medication status. This suggests that altered local circuit function supporting high-frequency oscillatory activity in prefrontal cortex ensembles may serve as the pathophysiological substrate of cognitive control deficits in schizophrenia.

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Gamma Band Oscillations Reveal Neural Network Cortical Coherence Dysfunction in Schizophrenia Patients

Cited by 399 publications

References 107 publications

Cortical source estimates of gamma band amplitude and phase are different in schizophrenia

Cortical source estimates of gamma band amplitude and phase are different in schizophrenia

Modeling Gaba Alterations in Schizophrenia: A Link Between Impaired Inhibition and Altered Gamma and Beta Range Auditory Entrainment

Gamma Oscillatory Power is Impaired During Cognitive Control Independent of Medication Status in First-Episode Schizophrenia

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