Amygdala Connectivity in Autism Spectrum Disorder

描述(由申请人提供)：自闭症谱系障碍(ASD)是一组在生命的头2-4年被诊断为神经发育状况的疾病，包括社交和沟通障碍。虽然许多大脑区域可能参与ASD，但杏仁核一直是一个非常感兴趣的区域，因为它在情绪行为中发挥作用，以及它与其他大脑区域的大量联系也与ASD有关。在ASD受试者中已经证实了杏仁核功能的异常，初步研究已经在ASD成人的身体组织中发现了杏仁核神经解剖学的改变。此外，几项磁共振成像(MRI)研究表明，在年轻的ASD受试者中，杏仁核增大，而且这种增大发生在生命早期。最近的报告不仅证实了这种增大，而且还发现了自闭症儿童在出生后最初几年杏仁核生长的多种模式。这些结果表明，杏仁核可能位于ASD异常脑网络的中心，并且在ASD的不同组中，杏仁核的病理可能有所不同。这些发现也提出了杏仁核和其他大脑区域之间的连接模式在ASD中发生改变的可能性。然而，与杏仁核相关的白质通路的潜在变化还没有得到彻底的研究。弥散张量成像(DTI)允许在体内可视化和研究大脑中的通路。DTI研究已经开始识别成人ASD大脑中的白质异常，但还没有研究研究在生命早期何时出现ASD症状，何时杏仁核异常增大最为明显。这项拟议的研究将利用DTI来研究患有ASD的学龄前儿童和典型发育中的对照组儿童的杏仁核连接。通过几年来检查幼儿杏仁核连接的完整性，拟议的研究将大大有助于我们对自闭症杏仁核异常的理解。此外，通过研究大量ASD表型儿童的脑白质通路，本研究试图进一步确定ASD神经病理的特定亚型。

DESCRIPTION (provided by applicant): Autism spectrum disorder (ASD) is a group of neurodevelopmental conditions diagnosed in the first 2-4 years of life which includes deficits in social interaction and communication. Although many brain regions are likely involved in ASD, the amygdala has been an area of great interest due to its role in emotional behavior and its numerous connections to other brain regions also implicated in ASD. Abnormal amygdala function has been demonstrated in ASD subjects and initial studies have identified altered amygdala neuroanatomy in post- mortem tissue from ASD adults. In addition, several magnetic resonance imaging (MRI) studies demonstrate that the amygdala is enlarged in young ASD subjects and that this enlargement occurs early in life. Recent reports not only confirm this enlargement but have also identified multiple patterns of amygdala growth in the first few years of life in children with ASD. These results suggest that the amygdala may be at the center of an abnormal brain network in ASD, and that amygdala pathology may vary across different groups in ASD. These findings also raise the possibility that the pattern of connectivity between the amygdala and other brain regions is altered in ASD. However, potential alterations in the white-matter pathways associated with the amygdala have not been thoroughly investigated. Diffusion tensor imaging (DTI) allows for in vivo visualization and investigation of pathways in the brain. DTI studies have already begun to identify white-matter abnormalities in the adult ASD brain, but no studies have investigated amygdala connectivity early in life when ASD symptoms first emerge and when abnormal amygdala enlargement is most pronounced. The proposed research will utilize DTI to investigate amygdala connectivity in a large longitudinal group of preschool-aged children with ASD and typically developing control children. By examining the integrity of connections to and from the amygdala in young children over several years, the proposed research will contribute significantly to our understanding of amygdala abnormalities in ASD. In addition, by examining white-matter pathways in a large group of extensively phenotyped children with ASD, this proposal seeks to further identify specific subtypes of neuropathology in ASD.