Advancing Diffusion Tensor Imaging and Analyses for Basic Alcohol Research

描述（由申请人提供）：本申请涉及广泛的挑战领域（15）：转化科学和特定挑战主题，15-AA-107：酒精依赖啮齿动物模型中扩散张量成像（DTI）程序的改进。正如本次挑战所提出的，拟议的努力旨在迅速推进DTI技术及其应用，以发现和记录酒精对出生前和出生后啮齿动物大脑的有害影响。一个主要的重点将是实现比目前可能的更快的成像时间。这将允许从离体到体内标本的DTI分析的扩展。为了补充成像方面的进展，还将开发新的方法，包括用于数据管理和分析的工具和软件，并将其应用于我们对胎儿和出生后小鼠大脑的分析。这些技术将用于扩展本实验室目前在小鼠模型中对胎儿酒精谱系障碍（FASD）的研究，并解决以下假设：母体酒精（乙醇）给药仅限于产前发育的非常早期阶段（对应于人类发育的第3周）导致永久性中枢神经系统损伤。我们实验室利用DTI的初步工作表明，急性酒精暴露后小鼠胎儿的纤维束形态发生了显着变化。拟议的努力将允许更快的成像时间比以前可能的，并将促进我们的成像分析扩展到产后时期。为此，将解决以下具体目标：目标1是开发新的DTI方法，使成像时间比目前可行的更快。这将通过使用主动染色技术、3D径向锁孔成像和应用于DTI的新型低温射频线圈来实现。目标#2是快速开发一个软件框架，用于基于无偏图谱生成的新的自动化小鼠大脑数据分析。该分析方法将用于DTI属性和连接模式的逐体素分析，以及DTI纤维追踪特定分析。目的#3是将先前目的中提出的方法应用于检查酒精对出生前和出生后小鼠大脑的影响。为此，将在产前第17天（GD 17）或产后第45或90天（PND 45，PND 90）检查对照小鼠和妊娠第7天暴露于酒精的小鼠的大脑纤维束形态（包括微结构完整性）。除了GD 17和PND 45和90脑的离体成像外，PND 45动物的子集将在体内成像。由于据报道产前酒精暴露与人类随后的酒精依赖有关，并且还增加了动物的酒精自我给药和偏好，因此在成像之前，将在许多行为电池中检查出生后动物，旨在评估其对急性酒精挑战的反应。研究者在各自领域的专业知识为成功完成这些目标提供了保证（成像技术开发领域的G. A约翰逊;图像分析软件开发中的Styner;和K.K. Sulik在FASD研究）和他们以前富有成效的合作努力。预计除了快速提供可直接应用于其他啮齿动物模型和研究问题的工具和方法外，拟议的挑战工作将提供有关产前酒精暴露的生物学（结构和功能）后果的重要新信息。 公共卫生相关性：拟议的工作涉及广泛的挑战领域（15）：转化科学和特定的挑战主题，15-AA-107：酒精依赖啮齿动物模型中扩散张量成像（DTI）程序的改进。正如本次挑战所提出的，拟议的努力旨在迅速推进DTI技术及其应用，以发现和记录酒精对出生前和出生后啮齿动物大脑的有害影响。一个主要的重点将是实现比目前可能的更快的成像时间。这将允许从固定到活标本的DTI分析的扩展。为了补充成像技术的进步，还将开发新的方法，包括用于数据管理和分析的工具和软件，并应用于我们对酒精引起的大脑异常的研究。

DESCRIPTION (provided by applicant): This application addresses the broad Challenge Area (15): Translational Science and specific Challenge Topic, 15-AA-107: Refinements of Procedures for Diffusion Tensor Imaging (DTI) in Rodent Models of Alcohol Dependence. As set forth for this Challenge, the proposed effort is designed to rapidly advance DTI technology and its application to discovery and documentation of alcohol's deleterious effects on the pre-and postnatal rodent brain. A major focus will be on achieving faster imaging times than are currently possible. This will allow the extension of DTI analyses from ex vivo to in vivo specimens. To complement the advances in imaging, new methodologies including tools and software for data management and analyses will also be developed and applied to our analyses of the fetal and postnatal mouse brain. These techniques will be utilized to extend this laboratory's current investigation of fetal alcohol spectrum disorders (FASD) in a mouse model and to address the hypothesis that maternal alcohol (ethanol) administration limited to very early stages of prenatal development (corresponding to week 3 of human development) results in permanent central nervous system damage. Preliminary work from our laboratory utilizing DTI has shown significant alterations in fiber tract morphology in the mouse fetus following acute alcohol exposure. The proposed effort will allow faster imaging times than previously possible and will facilitate extension of our imaging analyses into the postnatal period. To this end, the following specific Aims will be addressed: Aim # 1 is to develop new DTI methodologies that will allow faster imaging times than are currently feasible. This will be accomplished by the use of active staining techniques, 3D radial keyhole imaging, and a novel cryogenic radiofrequency coil applied to DTI. Aim #2 is to rapidly develop a software framework for a new, automated mouse brain data analysis based on an unbiased atlas generation. This analysis method will be used for voxel-wise analysis of DTI properties and connectivity patterns, as well as DTI fiber tractography-specific analysis. Aim #3 is to apply the methodologies advanced in the previous Aims to the examination of alcohol's effect on the pre- and postnatal mouse brain. For this, the brains of control mice and those exposed to alcohol on their 7th day of gestation, will be examined on their 17th prenatal day (GD 17), or their 45th or 90th postnatal day (PND 45, PND 90) for fiber tract morphology (including microstructural integrity). In addition to ex vivo imaging of the GD 17 and PND 45 and 90 brains, a subset of the PND 45 animals will be imaged in vivo. Since prenatal alcohol exposure is reportedly related to subsequent alcohol dependence in humans and also increases alcohol self administration and preference in animals, prior to imaging, the postnatal animals will be examined in a number of behavioral batteries designed to assess their reactions to acute alcohol challenge. Promise for the successful completion of these Aims is provided by the expertise of the investigators in their respective fields (G.A Johnson in imaging technology development; M.A. Styner in image analysis software development; and K.K. Sulik in FASD research) and their previously productive collaborative efforts. It is expected that in addition to rapidly providing tools and approaches that can be directly applied to other rodent models and research questions, the proposed Challenge effort will provide important new information regarding the biological (both structural and functional) consequences of prenatal alcohol exposure. PUBLIC HEALTH RELEVANCE: The proposed work addresses the broad Challenge Area (15): Translational Science and specific Challenge Topic, 15-AA-107: Refinements of Procedures for Diffusion Tensor Imaging (DTI) in Rodent Models of Alcohol Dependence. As set forth for this Challenge, the proposed effort is designed to rapidly advance DTI technology and its application to discovery and documentation of alcohol's deleterious effects on the pre-and postnatal rodent brain. A major focus will be on achieving faster imaging times than are currently possible. This will allow the extension of DTI analyses from fixed to live specimens. To complement the advances in imaging, new methodologies including tools and software for data management and analyses will also be developed and applied to our study of alcohol-induced brain abnormalities.