Amygdala Connectivity in Autism Spectrum Disorder

描述（由申请人提供）：自闭症谱系障碍（ASD）是一组在生命的前2 - 4年诊断出的神经发育状况，包括社交和沟通方面的缺陷。虽然许多大脑区域可能参与ASD，但杏仁核由于其在情感行为中的作用以及与ASD中涉及的其他大脑区域的众多连接而一直是人们非常感兴趣的区域。杏仁核功能异常已经在ASD受试者中得到证实，并且初步研究已经在ASD成人的死后组织中鉴定出杏仁核神经解剖学的改变。此外，一些磁共振成像（MRI）研究表明，杏仁核是扩大在年轻的ASD受试者，这种扩大发生在生命的早期。最近的报道不仅证实了这种扩大，而且还确定了自闭症儿童在生命最初几年中杏仁核生长的多种模式。这些结果表明，杏仁核可能是ASD异常脑网络的中心，并且杏仁核病理可能在ASD的不同组中有所不同。这些发现也提高了杏仁核和其他大脑区域之间的连接模式在ASD中改变的可能性。然而，与杏仁核相关的白质通路的潜在改变尚未得到彻底研究。 扩散张量成像（DTI）允许在体内可视化和调查的途径，在大脑中。DTI研究已经开始识别成人ASD大脑中的白质异常，但没有研究调查ASD症状首次出现时以及异常杏仁核扩大最明显时的杏仁核连接。拟议的研究将利用DTI来调查一个大型纵向组的学龄前ASD儿童和典型的发育对照儿童的杏仁核连接。通过检查几年来幼儿杏仁核连接的完整性，拟议的研究将大大有助于我们理解ASD中的杏仁核异常。此外，通过检查大量广泛表型的ASD儿童的白质通路，该提案旨在进一步确定ASD中神经病理学的特定亚型。

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.