MRS/fMRI Investigations of Adolescent Cannabis Use

我们建议的研究的总体目标是检查大麻对儿童发展的影响。 吸食大麻的青少年和健康非吸食者的额叶系统及其功能 青少年通过应用一套互补的磁共振(MR)技术和 神经心理评估。我们之前的调查发现了与年龄有关的差异 健康青少年的认知、形态测量和功能磁共振成像(FMRI)。 此外，我们还发现，早期开始使用大麻与贫穷之间存在关联。 神经心理表现，以及前扣带回和大脑皮质的异常激活 停药后即刻运动和记忆功能测定的前额叶背外侧皮质 大麻在成人中的使用。因此，我们建议研究大麻发病年龄的影响。 在两个青少年队列中使用：1)报告至少100次使用的14岁队列 大麻；2)一个18岁的队列，他们报告了相同数量的大麻使用量，但谁这样做了 直到他们16岁生日后才开始吸烟。这两组人将与年龄匹配的非 吸烟的青少年。尽管大量证据表明两者之间存在关联 在大麻使用和额叶执行功能改变之间，很难研究和 记录与大麻有关的人脑功能变化，特别是在青春期。 在这个方案中，我们将利用高空间分辨率和更高的信噪比 由互补的高场磁共振技术提供以研究化学和功能的影响 大麻在额部大脑区域的使用，已知这些区域在 青春期。具体地说，这项研究将结合焦点功能磁共振大胆技术，使用 在3特斯拉的认知和情感挑战范式，以及单体素GABA谱 扣带在4特斯拉，与执行功能的神经心理测量，以解决 额叶发育的脑区是否更容易受到非法药物使用的影响 是大麻使用的早发和晚发。我们相信这些免费的大脑测量方法 功能将为抑制加工和决策的神经机制提供新的见解。 对滥用大麻的青少年进行干预，这对早期干预和 补救措施。

The overall aim of our proposed study is to examine the effects of marijuana on the development of frontal lobe systems and their function in marijuana-smoking adolescents and healthy non-using adolescents by applying a complementary set of magnetic resonance (MR) techniques and neuropsychological assessments. Our previous investigations have identified age-related differences in cognition, morphometry and functional magnetic resonance imaging (fMRI) in healthy adolescents. Furthermore, we have found an association between early onset of marijuana use and poorer neuropsychological performance, as well as abnormal cortical activation in the anterior cingulate and dorsal lateral prefrontal cortex on measures of motor and memory function shortly after cessation of marijuana use in adults. We therefore propose to examine the effects of age of onset of marijuana use in two adolescent cohorts: 1) a 14 year old cohort who report a minimum of 100 episodes of using marijuana; and 2) an 18 year old cohort who report the same amount of marijuana usage, but who did not begin smoking until after their 16thbirthday. Both groups will be compared to age matched non- smoking adolescents. Although significant evidence has accumulated indicating an association between marijuana use and altered frontal-executive function, it has been difficult to study and document functional human brain changes associated with marijuana, particularly during adolescence. In this proposal, we will take advantage of the high spatial resolution and increased signal to noise offered by complementary high field MR techniques to investigate chemical and functional effects of marijuana use in frontal brain regions that are known to undergo maturational refinements during adolescence. Specifically, this study will incorporate focal functional MR BOLD techniques using cognitive and affective challenge paradigms at 3 Tesla, and single voxel GABA spectroscopy of the cingulate at 4 Tesla, with neuropsychological measures of executive function, in order to address the question of whether developing frontal brain regions are more vulnerable to illicit drug use when there is an early versus late onset of marijuana use. We believe these complimentary measures of brain function will provide new insights into the neural mechanisms of inhibitory processing and decision- making in adolescents who abuse marijuana, which has implications for early intervention and remediation.