Functional Disconnection Between the Prefrontal and Parietal Cortices During Working Memory Processing in Schizophrenia: A [<sup>15</sup>O]H<sub>2</sub>O PET Study

한글 요약

조현병에서 작업기억을 담당하는 전두엽-두정엽 회로의 상호작용이 손상되어 있는지를 [15O]H2O 양전자방출단층촬영(PET)으로 직접 살핀 연구입니다. 조현병 환자와 건강한 대조군이 그림을 순서대로 기억하는 n-back 작업기억 과제를 수행하는 동안 국소 뇌혈류 변화를 측정하고, 외측 전전두엽의 활성이 다른 활성 영역과 얼마나 함께 움직이는지를 집단별로 비교했습니다. 대조군은 배외측 전전두엽이 활성화되고 그 활성이 양쪽 하두정엽 활성과 뚜렷한 상관을 보였지만, 환자군은 대신 복외측 전전두엽이 활성화되었고 어떤 영역과도 상관이 나타나지 않았습니다. 이는 조현병의 작업기억 결함이 개별 영역의 문제를 넘어 전두엽과 두정엽 사이의 기능적 단절에서 비롯될 수 있음을 보여 줍니다.

OBJECTIVE: The prefrontal-parietal circuits have been reported to play an important role in working memory. The purpose of this study was to use direct neuroimaging to address whether interregional correlation in the prefrontal-parietal circuits is impaired in schizophrenia.

METHOD: [(15)O]H(2)O positron emission tomography was used to compare regional blood flow changes in 12 schizophrenic and 12 healthy comparison subjects during the n-back sequential-picture working memory task. Interregional correlation was assessed by correlating the regional activation of the lateral prefrontal area with that of other activated areas in each subject group.

RESULTS: Dorsolateral prefrontal activation was observed around the right superior frontal sulcus in the healthy subjects, and ventrolateral prefrontal activation below the right inferior frontal sulcus was observed in the schizophrenic patients. Activation in the right lateral prefrontal cortex was significantly correlated with activation in the bilateral inferior parietal region in the healthy subjects but was not correlated with any regional activation in the patients.

CONCLUSIONS: The findings suggest prefrontal-parietal functional disconnection, particularly prefrontal dissociation and abnormal prefrontal-parietal interaction, during working memory processing in schizophrenia.