Dataset Information

Association of a Serotonin Receptor 2A Gene Polymorphism with Visual Sustained Attention in Early-Onset Schizophrenia Patients and their Non-Psychotic Siblings.

ABSTRACT: The serotonin receptor 2A gene polymorphism is associated with attentional processes in schizophrenia. However, the specificity of the underlying cognitive constructs affected within this domain requires further elucidation. We carried out the first investigation of whether the TC/CC genotype of the 5-HT2A T102C polymorphism confers impairments in early-onset schizophrenia (EOS; onset of psychotic symptoms before age 18) but not in healthy siblings, the putative mechanism being that serotonergic inhibitory modulation of prefrontal dopamine is impaired in the presence of the C allele which in turn is a genetic risk marker for schizophrenia. Fifty-three EOS outpatients and 46 of their non-psychotic siblings (no current Axis I diagnoses) were genotyped for 5-HT2A T102C polymorphism. The Positive and Negative Syndrome Scale (PANSS) was used to assess symptomatology severity. Diagnostic classification was based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Structured Clinical Interview. The Degraded-Stimulus Continuous Performance Test (DS-CPT) was used to measure sustained focused attention. As predicted, EOS probands produced fewer correct responses (hit rate) and demonstrated poorer perceptual sensitivity compared with the healthy siblings. The C allele at codon 102 was associated with fewer correct responses compared with the TT genotype. There was no significant relationship between the polymorphism and clinical parameters, as measured using the PANSS. Our findings suggest that the C allele may be related to sustained attentional impairments in EOS.

SUBMITTER: Vyas NS

PROVIDER: S-EPMC3501364 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature

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Association of a Serotonin Receptor 2A Gene Polymorphism with Visual Sustained Attention in Early-Onset Schizophrenia Patients and their Non-Psychotic Siblings.

Vyas Nora S NS Lee Yohan Y Ahn Kwangmi K Ternouth Andrew A Stahl Daniel R DR Al-Chalabi Ammar A Powell John F JF Puri Basant K BK

Aging and disease 20120630 4

The serotonin receptor 2A gene polymorphism is associated with attentional processes in schizophrenia. However, the specificity of the underlying cognitive constructs affected within this domain requires further elucidation. We carried out the first investigation of whether the TC/CC genotype of the 5-HT2A T102C polymorphism confers impairments in early-onset schizophrenia (EOS; onset of psychotic symptoms before age 18) but not in healthy siblings, the putative mechanism being that serotonergic ...[more]

PMID: 23185710

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Project description:BACKGROUND:Quantitative endophenotypes are needed to better understand the pathogenesis of schizophrenia. The psychobiological model of temperament and character suggests that personality traits are heritable and regulated by brain systems influencing schizophrenia susceptibility. Thus, measures of temperament and character may serve as schizophrenia-related endophenotypes in individuals with schizophrenia and their non-psychotic siblings. METHODS:Individuals with schizophrenia (n=35), their non-psychotic siblings (n=34), controls (n=63), and their siblings (n=56) participated in a study of the clinical, neurocognitive and neuromorphological characteristics of schizophrenia. A mixed-model approach assessed group differences on the Temperament and Character Inventory (TCI). Neurocognitive deficits and psychopathology were correlated with the TCI. Configurations of TCI domains were examined using a generalized linear model. RESULTS:Individuals with schizophrenia and their non-psychotic siblings had higher harm avoidance than controls and their siblings. Individuals with schizophrenia had lower self-directedness and cooperativeness, and higher self-transcendence than their non-psychotic siblings, controls, and the siblings of controls. Neurocognition was not related to temperament and character in individuals with schizophrenia or either control group. In non-psychotic siblings, self-directedness and cooperativeness were correlated with working memory and crystallized IQ. CONCLUSION:Evidence supports harm avoidance as a schizophrenia-related endophenotype. An increased risk of schizophrenia may be associated with asociality (configured as high harm avoidance and low reward dependence), schizotypy (configured as low self-directedness, low cooperativeness, and high self-transcendence), and neurocognitive deficits (poor executive functioning, working/episodic memory, attention, and low IQ). The non-psychotic siblings demonstrated features of a mature character profile including strong crystallized IQ, which may confer protection against psychopathology.

Project description:In a crowded visual scene, attention must be distributed efficiently and flexibly over time and space to accommodate different contexts. It is well established that selective attention enhances the corresponding neural responses, presumably implying that attention would persistently dwell on the task-relevant item. Meanwhile, recent studies, mostly in divided attentional contexts, suggest that attention does not remain stationary but samples objects alternately over time, suggesting a rhythmic view of attention. However, it remains unknown whether the dynamic mechanism essentially mediates attentional processes at a general level. Importantly, there is also a complete lack of direct neural evidence reflecting whether and how the brain rhythmically samples multiple visual objects during stimulus processing. To address these issues, in this study, we employed electroencephalography (EEG) and a temporal response function (TRF) approach, which can dissociate responses that exclusively represent a single object from the overall neuronal activity, to examine the spatiotemporal characteristics of attention in various attentional contexts. First, attention, which is characterized by inhibitory alpha-band (approximately 10 Hz) activity in TRFs, switches between attended and unattended objects every approximately 200 ms, suggesting a sequential sampling even when attention is required to mostly stay on the attended object. Second, the attentional spatiotemporal pattern is modulated by the task context, such that alpha-mediated switching becomes increasingly prominent as the task requires a more uniform distribution of attention. Finally, the switching pattern correlates with attentional behavioral performance. Our work provides direct neural evidence supporting a generally central role of temporal organization mechanism in attention, such that multiple objects are sequentially sorted according to their priority in attentional contexts. The results suggest that selective attention, in addition to the classically posited attentional "focus," involves a dynamic mechanism for monitoring all objects outside of the focus. Our findings also suggest that attention implements a space (object)-to-time transformation by acting as a series of concatenating attentional chunks that operate on 1 object at a time.

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Dataset Information

Association of a Serotonin Receptor 2A Gene Polymorphism with Visual Sustained Attention in Early-Onset Schizophrenia Patients and their Non-Psychotic Siblings.

Publications

Association of a Serotonin Receptor 2A Gene Polymorphism with Visual Sustained Attention in Early-Onset Schizophrenia Patients and their Non-Psychotic Siblings.

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