Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Edinburgh, Scotland, UK.
Curr Pharm Des. 2012;18(4):434-42. doi: 10.2174/138161212799316235.
Measures of cortical folding ('gyrification') and connectivity are both reported to be disrupted in schizophrenia. There are also reports that increases in prefrontal gyrification may be predictive of subsequent illness in individuals at familial risk of the disorder. Such measures therefore have important potential clinical relevance. The nature of the relationship between cortical morphology and underlying connectivity is however unclear. In the current study we sought to explore the relationship between measures of gyrification and functional connectivity in a cohort of individuals at high genetic risk for the disorder. The theoretical background is based on the hypothesis that increased gyrification index (GI) in the prefrontal cortex may reflect increased short range regional connectivity. The cohort comprised 68 young unaffected relatives of schizophrenia patients and 21 healthy controls. Cortical folding was assessed using an automated Gyrification Index method (A-GI). Participants performed the Hayling sentence completion paradigm in the scanner and measures of functional connectivity were assessed using a correlation based approach. In the high risk subjects significant positive associations were found between prefrontal GI and prefrontal lateral-medial connectivity, while a negative correlation was found between prefrontal GI and prefrontal-thalamic connectivity. These associations indicate that measures describing morphological features of the brain surface relate to measures of underlying functional connectivity in the high risk subjects. Correlations in high risk people were more pronounced than in control subjects. We suggest our previous finding of increased prefrontal gyrification may therefore relate to increased local short range prefrontal connectivity and reduced long range connectivity.
皮层褶皱（“脑回形成”）和连通性的测量都被报道在精神分裂症中受到破坏。也有报道称，前额叶脑回增加可能预示着具有该疾病家族风险的个体随后会患病。因此，这些措施具有重要的潜在临床意义。然而，皮层形态与潜在连通性之间的关系尚不清楚。在目前的研究中，我们试图探索高遗传风险个体的脑回形成和功能连通性之间的关系。理论背景基于这样的假设，即前额叶皮层的增加脑回形成指数（GI）可能反映了短程区域连通性的增加。该队列包括 68 名未受影响的精神分裂症患者的年轻亲属和 21 名健康对照者。使用自动脑回形成指数方法（A-GI）评估皮层折叠。参与者在扫描仪中执行海林句子完成范式，使用基于相关性的方法评估功能连通性的测量。在高风险受试者中，发现前额叶 GI 与前额叶外侧-内侧连通性之间存在显著正相关，而前额叶 GI 与前额叶-丘脑连通性之间存在显著负相关。这些关联表明，描述大脑表面形态特征的测量与高风险受试者潜在功能连通性的测量有关。高风险人群中的相关性比对照组更明显。我们认为，我们之前发现的前额叶脑回增加可能与前额叶局部短程连通性增加和长程连通性减少有关。
