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Journal ArticleDOI

Failure to deactivate in the prefrontal cortex in schizophrenia: dysfunction of the default mode network?

TL;DR: Patients with schizophrenia show both failure to activate and failure to deactivate during performance of a working memory task, including an area in the anterior prefrontal/anterior cingulate cortex that corresponds to one of the two midline components of the ‘default mode network’ implicated in functions related to maintaining one's sense of self.
Abstract: BackgroundFunctional imaging studies using working memory tasks have documented both prefrontal cortex (PFC) hypo- and hyperactivation in schizophrenia. However, these studies have often failed to consider the potential role of task-related deactivation.MethodThirty-two patients with chronic schizophrenia and 32 age- and sex-matched normal controls underwent functional magnetic resonance imaging (fMRI) scanning while performing baseline, 1-back and 2-back versions of the n-back task. Linear models were used to obtain maps of activations and deactivations in the groups.ResultsThe controls showed activation in the expected frontal regions. There were also clusters of deactivation, particularly in the anterior cingulate/ventromedial PFC and the posterior cingulate cortex/precuneus. Compared to the controls, the schizophrenic patients showed reduced activation in the right dorsolateral prefrontal cortex (DLPFC) and other frontal areas. There was also an area in the anterior cingulate/ventromedial PFC where the patients showed apparently greater activation than the controls. This represented a failure of deactivation in the schizophrenic patients. Failure to activate was a function of the patients' impaired performance on the n-back task, whereas the failure to deactivate was less performance dependent.ConclusionsPatients with schizophrenia show both failure to activate and failure to deactivate during performance of a working memory task. The area of failure of deactivation is in the anterior prefrontal/anterior cingulate cortex and corresponds to one of the two midline components of the ‘default mode network’ implicated in functions related to maintaining one's sense of self.
Citations
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Journal ArticleDOI
TL;DR: It is shown that inhibitory synaptic transmission, such as miniature and evoked inhibitory postsynaptic currents (mIPSCs, eIPSCs), is significantly reduced in the mPFC of NL2 R215H KI mice, suggesting a pivotal role of Nlgn 2 in maintaining E/I balance in themPFC and in the maintenance of normal behaviors governed by the m PFC.

13 citations

Journal ArticleDOI
TL;DR: This review summarizes findings of the effects of nicotinic drugs on three topics related to intrinsic brain network activity: the default mode network, a group of brain areas for which activity is maximal at rest and reduced during cognitive tasks, the salience network, and multi-scale complex network dynamics.

13 citations


Cites background or methods from "Failure to deactivate in the prefro..."

  • ...Patients are similarly impaired in their ability to deactivate the DMN as task difficulty is increased [41,52,53]....

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  • ...Patients inappropriately recruit the DMN, as evidenced by hyperactivity of the network during an auditory oddball task [51], working memory tasks [41,52,53], and language (semantic priming) tasks [54]....

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Journal ArticleDOI
TL;DR: The relationship between striatal dopamine synthesis capacity and frontostriatal FC is different between responders to first-line treatment and clozapine treatment in schizophrenia, indicating that a different pathophysiology could underlie schizophrenia in patients who respond to first -line treatments relative to those who do not.
Abstract: BACKGROUND Given that only a subgroup of patients with schizophrenia responds to first-line antipsychotic drugs, a key clinical question is what underlies treatment response. Observations that prefrontal activity correlates with striatal dopaminergic function, have led to the hypothesis that disrupted frontostriatal functional connectivity (FC) could be associated with altered dopaminergic function. Thus, the aim of this study was to investigate the relationship between frontostriatal FC and striatal dopamine synthesis capacity in patients with schizophrenia who had responded to first-line antipsychotic drug compared with those who had failed but responded to clozapine. METHODS Twenty-four symptomatically stable patients with schizophrenia were recruited from Seoul National University Hospital, 12 of which responded to first-line antipsychotic drugs (first-line AP group) and 12 under clozapine (clozapine group), along with 12 matched healthy controls. All participants underwent resting-state functional magnetic resonance imaging and [18F]DOPA PET scans. RESULTS No significant difference was found in the total PANSS score between the patient groups. Voxel-based analysis showed a significant correlation between frontal FC to the associative striatum and the influx rate constant of [18F]DOPA in the corresponding region in the first-line AP group. Region-of-interest analysis confirmed the result (control group: R2 = 0.019, p = 0.665; first-line AP group: R2 = 0.675, p < 0.001; clozapine group: R2 = 0.324, p = 0.054) and the correlation coefficients were significantly different between the groups. CONCLUSIONS The relationship between striatal dopamine synthesis capacity and frontostriatal FC is different between responders to first-line treatment and clozapine treatment in schizophrenia, indicating that a different pathophysiology could underlie schizophrenia in patients who respond to first-line treatments relative to those who do not.

13 citations

Journal ArticleDOI
TL;DR: A robust reduction of cortical thickness in the left parahippocampal gyrus (PHG) in G allele homozygotes of GAD1 rs3749034 is shown, pointing to the importance of the GABAergic system in the pathogenesis of schizophrenia.

12 citations

Journal ArticleDOI
TL;DR: The proposed MFBA method may help distinguish networks or oscillators in the human brain, reveal subtle alternations of networks through locating their dominant frequency band, and present potential to interpret the neuropathology disruptions.
Abstract: The human brain is a complex system composed by several large scale intrinsic networks with distinct functions. The low frequency oscillation (LFO) signal of blood oxygen level dependent (BOLD), measured through resting-state fMRI, reflects the spontaneous neural activity of these networks. We propose to characterize these networks by applying the multiple frequency bands analysis (MFBA) to the LFO time courses (TCs) resulted from the group independent component analysis (ICA). Specifically, seven networks, including the default model network (DMN), dorsal attention network (DAN), control executive network (CEN), salience network, sensorimotor network, visual network and limbic network, are identified. After the power spectral density (PSD) analysis, the amplitude of low frequency fluctuation (ALFF) and the fractional amplitude of low frequency fluctuation (fALFF) is determined in three bands: <0.1 Hz; slow-5; and slow-4. Moreover, the MFBA method is applied to reveal the frequency-dependent alternations of fALFF for seven networks in schizotypal personality disorder (SPD). It is found that seven networks can be divided into three categories: the advanced cognitive networks, primary sensorimotor networks and limbic networks, and their fALFF successively decreases in both slow-4 and slow-5 bands. Comparing to normal control group, the fALFF of DMN, DAN and CEN in SPD tends to be higher in slow-5 band, but lower in slow-4. Higher fALFF of sensorimotor and visual networks in slow-5, higher fALFF of limbic network in both bands have been observed for SPD group. The results of ALFF are consistent with those of fALFF. The proposed MFBA method may help distinguish networks or oscillators in the human brain, reveal subtle alternations of networks through locating their dominant frequency band, and present potential to interpret the neuropathology disruptions.

12 citations

References
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Journal ArticleDOI
TL;DR: A review of the research carried out by the Analysis Group at the Oxford Centre for Functional MRI of the Brain (FMRIB) on the development of new methodologies for the analysis of both structural and functional magnetic resonance imaging data.

12,097 citations

Book
01 Jan 1966
TL;DR: This book discusses statistical decision theory and sensory processes in signal detection theory and psychophysics and describes how these processes affect decision-making.
Abstract: Book on statistical decision theory and sensory processes in signal detection theory and psychophysics

11,820 citations


"Failure to deactivate in the prefro..." refers methods in this paper

  • ...The behavioural measure used was the signal detection theory index of sensitivity, dk (Green & Swets, 1966)....

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Journal ArticleDOI
TL;DR: A baseline state of the normal adult human brain in terms of the brain oxygen extraction fraction or OEF is identified, suggesting the existence of an organized, baseline default mode of brain function that is suspended during specific goal-directed behaviors.
Abstract: A baseline or control state is fundamental to the understanding of most complex systems. Defining a baseline state in the human brain, arguably our most complex system, poses a particular challenge. Many suspect that left unconstrained, its activity will vary unpredictably. Despite this prediction we identify a baseline state of the normal adult human brain in terms of the brain oxygen extraction fraction or OEF. The OEF is defined as the ratio of oxygen used by the brain to oxygen delivered by flowing blood and is remarkably uniform in the awake but resting state (e.g., lying quietly with eyes closed). Local deviations in the OEF represent the physiological basis of signals of changes in neuronal activity obtained with functional MRI during a wide variety of human behaviors. We used quantitative metabolic and circulatory measurements from positron-emission tomography to obtain the OEF regionally throughout the brain. Areas of activation were conspicuous by their absence. All significant deviations from the mean hemisphere OEF were increases, signifying deactivations, and resided almost exclusively in the visual system. Defining the baseline state of an area in this manner attaches meaning to a group of areas that consistently exhibit decreases from this baseline, during a wide variety of goal-directed behaviors monitored with positron-emission tomography and functional MRI. These decreases suggest the existence of an organized, baseline default mode of brain function that is suspended during specific goal-directed behaviors.

10,708 citations


"Failure to deactivate in the prefro..." refers background or result in this paper

  • ...This interpretation is supported by (a) the spatial correspondence between this area and that identified in studies of the default mode network (e.g. Gusnard et al. 2001 ; Raichle et al. 2001), and (b) the fact that the controls in our study showed deactivation in the same area while performing the n-back task....

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  • ...the inferior parietal cortex and parts of the temporal lobe including the hippocampus), these are thought to constitute a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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  • ...…is supported by (a) the spatial correspondence between this area and that identified in studies of the default mode network (e.g. Gusnard et al. 2001 ; Raichle et al. 2001), and (b) the fact that the controls in our study showed deactivation in the same area while performing the n-back task....

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  • ...…a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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Journal ArticleDOI
TL;DR: This study constitutes, to the knowledge, the first resting-state connectivity analysis of the default mode and provides the most compelling evidence to date for the existence of a cohesive default mode network.
Abstract: Functional imaging studies have shown that certain brain regions, including posterior cingulate cortex (PCC) and ventral anterior cingulate cortex (vACC), consistently show greater activity during resting states than during cognitive tasks. This finding led to the hypothesis that these regions constitute a network supporting a default mode of brain function. In this study, we investigate three questions pertaining to this hypothesis: Does such a resting-state network exist in the human brain? Is it modulated during simple sensory processing? How is it modulated during cognitive processing? To address these questions, we defined PCC and vACC regions that showed decreased activity during a cognitive (working memory) task, then examined their functional connectivity during rest. PCC was strongly coupled with vACC and several other brain regions implicated in the default mode network. Next, we examined the functional connectivity of PCC and vACC during a visual processing task and show that the resultant connectivity maps are virtually identical to those obtained during rest. Last, we defined three lateral prefrontal regions showing increased activity during the cognitive task and examined their resting-state connectivity. We report significant inverse correlations among all three lateral prefrontal regions and PCC, suggesting a mechanism for attenuation of default mode network activity during cognitive processing. This study constitutes, to our knowledge, the first resting-state connectivity analysis of the default mode and provides the most compelling evidence to date for the existence of a cohesive default mode network. Our findings also provide insight into how this network is modulated by task demands and what functions it might subserve.

6,025 citations


"Failure to deactivate in the prefro..." refers background in this paper

  • ...the inferior parietal cortex and parts of the temporal lobe including the hippocampus), these are thought to constitute a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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  • ...…a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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Journal ArticleDOI
TL;DR: This work explores the possibility that there might be a baseline or resting state of brain function involving a specific set of mental operations, including the manner in which a baseline is defined and the implications of such a baseline for the understanding ofbrain function.
Abstract: Functional brain imaging in humans has revealed task-specific increases in brain activity that are associated with various mental activities. In the same studies, mysterious, task-independent decreases have also frequently been encountered, especially when the tasks of interest have been compared with a passive state, such as simple fixation or eyes closed. These decreases have raised the possibility that there might be a baseline or resting state of brain function involving a specific set of mental operations. We explore this possibility, including the manner in which we might define a baseline and the implications of such a baseline for our understanding of brain function.

3,285 citations


"Failure to deactivate in the prefro..." refers background or result in this paper

  • ...Two studies, however, had opposite results to ours : Harrison et al. (2007) found that 12 schizophrenic patients showed greater deactivation of both the anterior and posterior cingulate midline loci than in 14 controls during a task requiring response suppression. Using an auditory oddball task, Garrity et al. (2007) found that 21 patients with schizophrenia showed a complex pattern of abnormality compared to 22 normal controls, but deactivation was increased in the anterior cingulate/ superior medial frontal gyri. The remaining two studies (Bluhm et al. 2007 ; Zhou et al. 2007) focused exclusively on connectivity, and cannot be directly compared with our findings. Of note, Kennedy et al. (2006) have also documented default mode network dysfunction in adult high-functioning autisticspectrum patients, although they found that the failure of deactivation affected both the anterior and posterior midline loci of the network....

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  • ...Gusnard et al. 2001 ; Raichle et al. 2001), and (b) the fact that the controls in our study showed deactivation in the same area while performing the n-back task. Menzies et al. (2007) also interpreted the failure to deactivate they found in schizophrenia in terms of default mode network dysfunction. However, as neither we nor Menzies et al. (2007) set out specifically to examine default mode network function in schizophrenia, such an interpretation should be regarded as provisional....

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  • ...Two studies, however, had opposite results to ours : Harrison et al. (2007) found that 12 schizophrenic patients showed greater deactivation of both the anterior and posterior cingulate midline loci than in 14 controls during a task requiring response suppression. Using an auditory oddball task, Garrity et al. (2007) found that 21 patients with schizophrenia showed a complex pattern of abnormality compared to 22 normal controls, but deactivation was increased in the anterior cingulate/ superior medial frontal gyri....

    [...]

  • ...the inferior parietal cortex and parts of the temporal lobe including the hippocampus), these are thought to constitute a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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  • ...Gusnard et al. (2001) have also reviewed various lines of evidence that suggest that different parts of the default mode network are involved in gathering information about the world, orienting oneself to salient environmental stimuli, theory of mind and self-representation....

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How long can a schizophrenic go without sleep?

This represented a failure of deactivation in the schizophrenic patients.