Brain Changes with Cannabis and Methamphetamine

说明(申请人提供)：这项修订提案的总体目标是在南非现有磁共振成像/功能磁共振成像能力的基础上，应用新实施的结构和功能成像技术来检查南非西开普省地区严重吸食甲基苯丙胺或与大麻联合使用的青少年的脑功能。在过去的几年里，我们发起了麦克莱恩医院的脑成像中心(BIC)、哈佛医学院和斯泰伦博斯大学的脑成像小组(BIG)之间的研究合作，并通过NIDA赞助的补充补助金奖得以实现。拟议的R21旨在通过在磁共振方法和磁共振技术的应用方面对南非合作伙伴进行培训，同时收集关于甲基苯丙胺和大麻使用的影响的数据，来巩固和扩大这一合作。最近在南非安装的功能磁共振成像能力将通过以下方式扩大：a)就磁共振方法的基本概念提供讲习班和教程；b)介绍优化结构和功能成像协议的战略，以最大限度地提高图像质量，并促进在个人层面上以最佳方式同时记录功能与结构数据；c)审查开发和验证神经认知激活范式的方法，以便与功能磁共振一起使用；d)培训南非研究人员进行形态测量和功能成像数据的图像处理和分析，以发展利用SPM和Brain Voyager软件进行独立图像分析的能力；以及e)评估实施核磁共振光谱分析的硬件和软件需求。这些功能磁共振成像技术将被用于检验这样一种假设，即与匹配的不使用大麻的对照组(n=10)相比，南非西开普省地区13-17岁的青少年将出现额叶功能障碍，额叶功能障碍的衡量标准是前扣带回皮质(ACC)和背外侧前额叶皮质(DLPFC)的BOLD信号减少，这些青少年单独使用甲基苯丙胺(n=10)或与大麻联合使用(n=10)。然后，将根据在R21期间获得的数据准备R01应用程序。

DESCRIPTION (provided by applicant): The overall aims of this revised proposal are to build on existing MRI/functional MRI capacity in South Africa and to apply newly implemented structural and functional imaging techniques to examine brain function in adolescents of the Western Cape region of South Africa who are heavy users of methamphetamine alone or in combination with cannabis. Over the past several years we have initiated a research collaboration between the Brain Imaging Center (BIC) at McLean Hospital, Harvard Medical School and the Brain Imaging Group (BIG) at the University of Stellenbosch made possible through a NIDA sponsored supplementary grant award. The proposed R21 is designed to consolidate and extend this collaboration by training collaborative South African partners in MR methodology and the application of MR techniques while simultaneously collecting data on the effects of methamphetamine and cannabis use. Functional magnetic resonance imaging capacity, recently installed in South Africa, will be expanded by a) providing workshops and tutorials on fundamental concepts underlying MR methods; b) describing strategies for optimization of structural and functional imaging protocols in order to maximize image quality and facilitate optimal co- registration of functional to structural data at the individual level; c) reviewing approaches for development and validation of neurocognitive activation paradigms for use with fMRI; d) training of South African investigators in image processing and analysis of morphometric and functional imaging data to develop independent image analysis capacity using SPM and brain voyager software and; e) evaluating hardware and software needs for implementing MR spectroscopy. These fMRI techniques will be applied to test the hypothesis that frontal dysfunction, as measured by reduced BOLD signal in the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) will be present in adolescents, aged 13-17, of the Western Cape region of South Africa, who are heavy users of methamphetamine alone (n=10) or in combination with cannabis (n=10), relative to matched non-using controls (n=10). An R01 application will then be prepared based on the data acquired during the R21 period.