Are oscillatory brain responses generally reduced in schizophrenia during long sustained attentional processing?

Başar-Eroğlu, Canan; Schmiedt-Fehr, Christina; Mathes, Birgit; Zimmermann, Jörg; Brand, Andreas

doi:10.1016/j.ijpsycho.2008.07.004

Cited by 48 publications

(31 citation statements)

References 54 publications

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“…According to several previous studies, schizophrenia patients display both reduced spontaneous alpha activity and event related alpha (Alfimova and Uvarova 2008;Başar-Eroglu et al 2009;Iacono 1982;Itil et al 1972Itil et al , 1974Miyauchi et al 1990;Sponheim et al 1994Sponheim et al , 2000. Few studies discuss the common and extinct parameters of schizophrenia and bipolar disorder by means of anatomical and genetically analysis (Lim et al 1999;Roy et al 1998;McDonald et al 2004;Hoge et al 1999;Campbell et al 2004;Wright et al 2000).…”

Section: Comparison Of Bipolar Alpha Band Results With Schizophreniamentioning

confidence: 99%

“…Can the drastic breakdown of alpha be considered as a candidate biomarker in future, especially for differentiation between schizophrenia and other psychiatric disorders? Başar-Eroglu et al (2009) published results showing a 10-15% reduction in alpha responses among schizophrenic patients; Itil et al (1972Itil et al ( , 1974 also reported only a 10-15% reduction in EEG. This suggests that a very large alpha decrease in bipolar disease will possibly serve as a biomarker for differentiation from schizophrenia.…”

Section: Comparison Of Bipolar Alpha Band Results With Schizophreniamentioning

confidence: 99%

“…EEG Alpha activity was also found to be decreased in schizophrenia (Alfimova and Uvarova 2008;Iacono 1982;Itil et al 1972Itil et al , 1974Miyauchi et al 1990;Sponheim et al 1994Sponheim et al , 2000. Başar-Eroglu et al (2009) observed significantly reduced alpha responses in the range of 15% and Ford et al (2008) also reported reduced alpha response in schizophrenia.…”

Section: Introductionmentioning

confidence: 95%

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Brain’s alpha activity is highly reduced in euthymic bipolar disorder patients

et al. 2011

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Brain's alpha activity and alpha responses belong to major electrical signals that are related to sensory/cognitive signal processing. The present study aims to analyze the spontaneous alpha activity and visual evoked alpha response in drug free euthymic bipolar patients. Eighteen DSM-IV euthymic bipolar patients (bipolar I n = 15, bipolar II n = 3) and 18 healthy controls were enrolled in the study. Patients needed to be euthymic at least for 4 weeks and psychotrop free for at least 2 weeks. Spontaneous EEG (4 min eyes closed, 4 min eyes open) and evoked alpha response upon application of simple visual stimuli were analyzed. EEG was recorded at 30 positions. The digital FFT-based power spectrum analysis was performed for spontaneous eyes closed and eyes open conditions and the response power spectrum was also analyzed for simple visual stimuli. In the analysis of spontaneous EEG, the ANOVA on alpha responses revealed significant results for groups (F(1,34) = 8.703; P < 0.007). Post-hoc comparisons showed that spontaneous EEG alpha power of healthy subjects was significantly higher than the spontaneous EEG alpha power of euthymic patients. Furthermore, visual evoked alpha power of healthy subjects was significantly higher than visual evoked alpha power of euthymic patients (F(1,34) = 4.981; P < 0.04). Decreased alpha activity in spontaneous EEG is an important pathological EEG finding in euthymic bipolar patients. Together with an evident decrease in evoked alpha responses, the findings may lead to a new pathway in search of biological correlates of cognitive impairment in bipolar disorder.

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Section: Comparison Of Bipolar Alpha Band Results With Schizophreniamentioning

confidence: 99%

Section: Comparison Of Bipolar Alpha Band Results With Schizophreniamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

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Brain’s alpha activity is highly reduced in euthymic bipolar disorder patients

et al. 2011

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“…Although most neurophysiological studies assessing oscillatory activity in schizophrenic patients have focused on high-frequency oscillations (b, g) (Kwon et al, 1999;Spencer et al, 2003;Uhlhaas and Singer, 2006), alterations in lower frequencies have also been reported (Basar-Eroglu et al, 2009;Shin et al, 2010), which may be relevant to the emergence of schizophrenia symptoms given Clozapine reversal of PCP effect involves 5-HT 1A R L Kargieman et al the involvement of slow oscillations in cognitive processes and memory consolidation (Stickgold, 2005;Marshall et al, 2006). Here we report that PCP administration markedly reduced synchrony in mouse PFC, as assessed by SCO (0.15-4 Hz), 1-Hz oscillations, and the number of active phases.…”

Section: Discussionmentioning

confidence: 99%

Clozapine Reverses Phencyclidine-Induced Desynchronization of Prefrontal Cortex through a 5-HT1A Receptor-Dependent Mechanism

Kargieman

Riga

Artigas

et al. 2011

Neuropsychopharmacol

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The non-competitive NMDA receptor (NMDA-R) antagonist phencyclidine (PCP)Fused as a pharmacological model of schizophreniaFdisrupts prefrontal cortex (PFC) activity. PCP markedly increased the discharge rate of pyramidal neurons and reduced slow cortical oscillations (SCO; 0.15-4 Hz) in rat PFC. Both effects were reversed by classical (haloperidol) and atypical (clozapine) antipsychotic drugs. Here we extended these observations to mice brain and examined the potential involvement of 5-HT 2A and 5-HT 1A receptors (5-HT 2A R and 5-HT 1A R, respectively) in the reversal by clozapine of PCP actions. Clozapine shows high in vitro affinity for 5-HT 2A R and behaves as partial agonist in vivo at 5-HT 1A R. We used wild-type (WT) mice and 5-HT 1A R and 5-HT 2A R knockout mice of the same background (C57BL/6) (KO-1A and KO-2A, respectively). Local field potentials (LFPs) were recorded in the PFC of WT, KO-1A, and KO-2A mice. PCP (10 mg/kg, intraperitoneally) reduced SCO equally in WT, KO-2A, and KO-1A mice (58 ± 4%, 42 ± 7%, and 63 ± 7% of pre-drug values, n ¼ 23, 13, 11, respectively; po0.0003). Clozapine (0.5 mg/kg, intraperitoneally) significantly reversed PCP effect in WT and KO-2A mice, but not in KO-1A mice nor in WT mice pretreated with the selective 5-HT 1A R antagonist WAY-100635.The PCP-induced disorganization of PFC activity does not appear to depend on serotonergic function. However, the lack of effect of clozapine in KO-1A mice and the prevention by WAY-100635 indicates that its therapeutic action involves 5-HT 1A R activation without the need to block 5-HT 2A R, as observed with clozapine-induced cortical dopamine release.

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“…Zheng-yan (2005), Hogan et al (2003), Güntekin et al (2008), Yener et al (2007Yener et al ( , 2008Yener et al ( , 2009) and Dauwels et al (2009) published results on Alzheimer patients. Our research group and other groups on the topic of neuropsychiatric disorders initiated several reports on cognitive processes in schizophrenia (Başar-Eroglu et al 2009) and in two different states of bipolar disorders (Ö zerdem et al 2008a, b). The publications mentioned primarily aimed to show the changes in oscillatory behavior in the abovementioned diseases.…”

Section: Introductionmentioning

confidence: 99%

Sensory evoked and event related oscillations in Alzheimer’s disease: a short review

Yener¹,

Başar²

2010

Cogn Neurodyn

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Diagnosis and treatment of Alzheimer's disease (AD) depend on clinical evaluation and there is a strong need for an objective tool as a biomarker. Our group has investigated brain oscillatory responses in a small group of AD subjects. We found that the de novo (untreated) AD group differs from both the cholinergically-treated AD group and aged-matched healthy controls in theta and delta responses over left frontal-central areas after cognitive stimulation. On the contrary, the difference observed in AD groups upon a sensory visual stimulation includes response increase over primary or secondary visual sensorial areas compared to controls. These findings imply at least two different neural networks, depending on type of stimulation (i.e. cognitive or sensory). The default mode defined as activity in resting state in AD seems to be affected electrophysiologically. Coherences are also very valuable in observing the group differences, especially when a cognitive stimulus is applied. In healthy controls, higher coherence values are elicited after a cognitive stimulus than after a sensory task. Our findings support the notion of disconnectivity of cortico-cortical connections in AD. The differences in comparison of oscillatory responses upon sensory and cognitive stimulations and their role as a biomarker in AD await further investigation in series with a greater number of subjects.

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Are oscillatory brain responses generally reduced in schizophrenia during long sustained attentional processing?

Cited by 48 publications

References 54 publications

Brain’s alpha activity is highly reduced in euthymic bipolar disorder patients

Brain’s alpha activity is highly reduced in euthymic bipolar disorder patients

Clozapine Reverses Phencyclidine-Induced Desynchronization of Prefrontal Cortex through a 5-HT1A Receptor-Dependent Mechanism

Sensory evoked and event related oscillations in Alzheimer’s disease: a short review

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