کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6038594 | 1188803 | 2009 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Steady state and induced auditory gamma deficits in schizophrenia
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موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب شناختی
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چکیده انگلیسی
Steady state auditory evoked potentials (SSAEPs) in the electroencephalogram (EEG) and magnetoencephalogram (MEG) have been reported to be reduced in schizophrenia, most consistently to frequencies in the gamma range (40Â Hz and greater). The current study evaluated the specificity of this deficit over a broad range of stimulus frequencies and harmonics, the relationship between phase locking and signal power, and whether induced 40Â Hz activity was also affected. SSAEPs to amplitude modulated tones from 5 to 50Â Hz were obtained from subjects with schizophrenia (SZ) and healthy control subjects in 5Â Hz steps. Time-frequency spectral analysis was used to differentiate EEG activity synchronized in phase across trials using Phase Locking Factor (PLF) and Mean Power (MP) change from baseline activity. In the SSAEP frequency response condition, patients with SZ showed broad band reductions in both PLF and MP. In addition, the control subjects showed a more pronounced increase in PLF with increases in power compared to SZ subjects. A noise pulse embedded in 40Â Hz stimuli resulted in a transient reduction of PLF and MP at 40Â Hz in control subjects, while SZ showed diminished overall PLF. Finally, induced gamma (around 40Â Hz) response to unmodulated tone stimuli was also reduced in SZ, indicating that disturbances in this oscillatory activity are not confined to SSAEPs. In summary, SZ subjects show impaired oscillatory responses in the gamma range across a wide variety of experimental conditions. Reduction of PLF along with reduced MP may reflect abnormalities in the auditory cortical circuits, such as a reduction in pyramidal cell volume, spine density and alterations in GABAergic neurons.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NeuroImage - Volume 47, Issue 4, 1 October 2009, Pages 1711-1719
Journal: NeuroImage - Volume 47, Issue 4, 1 October 2009, Pages 1711-1719
نویسندگان
G.P. Krishnan, W.P. Hetrick, C.A. Brenner, A. Shekhar, A.N. Steffen, B.F. O'Donnell,