Prefrontal dysfunction in schizophrenia by use of brain functional neuroivnaging as an endophenotype

点击翻译按钮获取中文摘要

Psychiatric disorders are associated with prefrontal dysfunction, which leads to abnormalities in higher cognitive function. We investigated spatiotemporal characteristics of prefrontal cortical function in normal controls and patients with schizophrenia using multi-channel near-infrared spectroscopy (NIRS). During a verbal fluency task, the time-course pattern of oxygenated hemoglobin concentration ([oxy-Hb]) change differed significantly between patients with schizophrenia and normal controls. The reduced [oxy-Hb] change was significantly associated with poorer global assessment of functioning scores in schizophrenia (Takizawa, et al., 2008).In this scientific research, we investigated the relationship between prefrontal hemodynamic activation and the catechol-O-methyltranseferese (COMT val158met) genotype. A common functional polymorphism of COMT that metabolizes released dopamine has been a candidate that affects the prefrontal cortical function in schizophrenia. The increase of [o … More xy-Hb] in the met carriers during the task was significantly higher than that of val/val individuals in the frontopolar prefrontal cortex in schizophrenia.These results, consistent with findings from previous fMRI studies, suggest that the met allele may have the beneficial effect on prefrontal function in schizophrenia. Previous researches showed that the COMT met allele was associated with greater improvement of memory performance and negative symptoms in patients with schizophrenia treated with antipsychotic drugs. Taken together, prefrontal reactivity assessed by LAIRS might be useful for evaluation and prediction of medicinal benefits.We have examined the clinical usefulness of this noninvasive neuroimaging technique. The projects we are currently working on are : (1) to develop technology used as an aid in diagnosis and clinical evaluation including applicability to early intervention ; (2) to shed light on the understanding of brain pathophysiology by endophenotype studies ; (3) to test for evaluative and predictive values regarding benefits from pharmacological intervention. We hope that these attempts will contribute to the improvement of quality of treatment in mental disorders by introducing non-invasive neuroimaging techniques to clinical psychiatry. Less