Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
Schizophr Bull. 2012 Mar;38(2):285-94. doi: 10.1093/schbul/sbq074. Epub 2010 Jun 30.
Abnormal connectivity of the anticorrelated intrinsic networks, the task-negative network (TNN), and the task-positive network (TPN) is implicated in schizophrenia. Comparisons between schizophrenic patients and their unaffected siblings enable further understanding of illness susceptibility and pathophysiology. We examined the resting-state connectivity differences in the intrinsic networks between schizophrenic patients, their unaffected siblings, and healthy controls.
Resting-state functional magnetic resonance images were obtained from 25 individuals in each subject group. The posterior cingulate cortex/precuneus and right dorsolateral prefrontal cortex were used as seed regions to identify the TNN and TPN through functional connectivity analysis. Interregional connectivity strengths were analyzed using overlapped intrinsic networks composed of regions common to all subject groups.
Schizophrenic patients and their unaffected siblings showed increased connectivity in the TNN between the bilateral inferior temporal gyri. By contrast, schizophrenic patients alone demonstrated increased connectivity between the posterior cingulate cortex/precuneus and left inferior temporal gyrus and between the ventral medial prefrontal cortex and right lateral parietal cortex in the TNN. Schizophrenic patients exhibited increased connectivity between the left dorsolateral prefrontal cortex and right inferior frontal gyrus in the TPN relative to their unaffected siblings, though this trend only approached statistical significance in comparison to healthy controls.
Resting-state hyperconnectivity of the intrinsic networks may disrupt network coordination and thereby contribute to the pathophysiology of schizophrenia. Similar, though milder, hyperconnectivity of the TNN in unaffected siblings of schizophrenic patients may contribute to the identification of schizophrenia endophenotypes and ultimately to the determination of schizophrenia risk genes.
相关内在网络（负任务网络[TNN]和正任务网络[TPN]）的异常连接与精神分裂症有关。将精神分裂症患者与其未受影响的兄弟姐妹进行比较，可以进一步了解疾病易感性和病理生理学。我们研究了精神分裂症患者、未受影响的兄弟姐妹和健康对照组之间内在网络的静息态连接差异。
从每个受试者组中获得 25 名个体的静息态功能磁共振成像数据。使用后扣带回皮层/楔前叶和右侧背外侧前额叶作为种子区域，通过功能连接分析来识别 TNN 和 TPN。使用由所有受试者组共同区域组成的重叠内在网络来分析区域间连接强度。
精神分裂症患者及其未受影响的兄弟姐妹的双侧颞下回之间的 TNN 连接增强。相比之下，仅精神分裂症患者的 TNN 中后扣带回皮层/楔前叶与左侧颞下回之间以及腹内侧前额叶与右侧外侧顶叶之间的连接增强。与未受影响的兄弟姐妹相比，精神分裂症患者的 TPN 中左侧背外侧前额叶与右侧额下回之间的连接增强，尽管与健康对照组相比，这种趋势仅接近统计学意义。
内在网络的静息状态超连接可能破坏网络协调，从而导致精神分裂症的病理生理学。精神分裂症患者未受影响的兄弟姐妹中 TNN 的类似但较轻的超连接可能有助于识别精神分裂症的表型，并最终确定精神分裂症的风险基因。
