Early Brain Development in One and Two Year Olds

描述(申请人提供)：生命的头两年是出生后大脑发育最活跃的阶段，也可能是最关键的阶段。在大脑结构快速增长的同时，认知和运动功能的发展也同样迅速。尽管它对了解正常发育和精神分裂症和自闭症等神经发育障碍的早期起源很重要，但我们对这一关键时期的人脑发育的了解很少。虽然人们对MRI研究正常大脑发育的兴趣与日俱增，但到目前为止，大多数研究还没有包括生命的头几年，因为这个年龄段儿童的图像采集和图像分析非常具有挑战性。我们已经解决了这些挑战，并培养了一批罕见的已经接受过新生儿核磁共振成像的未来儿童。*此外，我们还开发了新颖和尖端的最先进的图像分析技术，为研究出生前两年的大脑发育提供了强大的工具。我们是世界上少数几个开发了研究儿童早期大脑发育所必需的专业知识的团体之一。我们建议用MRI对正常一岁和两岁儿童的大脑发育进行纵向研究。这项研究将利用目前资助的一项名为“高风险儿童的早期大脑发育”研究的160多名儿童的独特而庞大的队列，在这项研究中，所有受试者都将在出生后2-4周接受产前超声波和核磁共振检查，并在一岁和两岁时进行发育跟踪。使用新的自动分割和分割方法，我们将研究出生后头两年灰质和白质体积的区域变化。我们将使用一种创新的弥散张量成像(DTI)特性的定量纤维束造影术和我们小组开发的特定年龄的DTI图谱来评估白质束的发育，包括穹隆体束和皮质脊髓束。这些白质束弥散特性的成熟可以通过DTI和结构磁共振成像的共同注册直接与束的髓鞘形成进行比较。在生命的头两年，将使用复杂的三维脑图来评估大脑的区域发育。将评估大脑区域和白质束发育轨迹的性别差异。最后，我们将研究儿童早期侧脑室形状的变化。这项拟议的研究将提供有关早期大脑发育的关键、不可用的信息，并将直接提高我们对大脑正常发育的理解，并为未来对该年龄段神经发育障碍的研究提供基础。

DESCRIPTION (provided by applicant): The first two years of life is the most dynamic and perhaps the most critical phase of postnatal brain development. Concurrent with the rapid pace of structural brain growth is an equally rapid development of a wide range of cognitive and motor functions. In spite of its importance for understanding normal development and the early origins of neurodevelopment disorders such as schizophrenia and autism, our knowledge of human brain development in this crucial time period is minimal. While there has been growing interest in the study of normal brain development with MRI, most studies to date have not included the first few years of life because image acquisition and image analysis of children at this age is very challenging. We have addressed these challenges and have developed a rare prospective cohort of children who have already had neonatal MRIs.* In addition, we have developed novel and cutting edge, state-of-the-art image analysis techniques that provide powerful tools to study brain development in the first two years of life. We are one of the few groups in the world that has developed the expertise necessary to study very early brain development in children. We propose a longitudinal study of brain development with MRI in normal one and two year olds. This study will take advantage of a unique and large cohort of over 160 children who are enrolled in the currently funded study "Early Brain Development in High Risk Children" in which all subjects will have had prenatal ultrasounds and MRI's 2-4 weeks after birth and developmental follow-up at ages one and two years. Using novel automatic segmentation and parcellation methods, we will study regional changes in gray and white matter volumes over the first two years of life. The development of white matter tracts, including the corpus callosum and corticospinal tracts will be assessed using an innovative quantitative tractography of diffusion tensor imaging (DTI) properties and age-specific DTI atlases developed by our group. The maturation of diffusion properties in these white matter tracts can be directly compared to the myelination of the tracts through co-registration of DTI and structural MRIs. Regional brain growth over the first two years of life will be assessed with sophisticated three-dimensional brain mapping. Gender differences in the developmental trajectories of brain regions and white matter tracts will be assessed. Finally, we will study the changes in lateral ventricle shape in early childhood. The proposed study will provide critical, unavailable information about early brain development and will directly improve our understanding of brain normal development and provide the basis for future studies of neurodevelopment disorders in this age group.