MARIJUANA INTOXICATION AND BRAIN ACTIVATION

描述：(申请人摘要) 大麻是美国最常被滥用的非法药物。它 尤其令人担忧的是，这种药物被大量的 青少年。因此，大麻的急性和慢性影响及其 活性成分，包括THC，具有相当大的研究兴趣和 临床意义。一些调查人员展示了改变 通过神经心理测试对长期吸食大麻者的大脑功能的影响。 随着最近非侵入性技术的出现，有可能 在人类认知测试中测量脑血流量。在……里面 在这种激活研究中，CBF可作为局部脑功能的指标。 所有四项关于慢性大麻吸烟者CBF的研究都发现 全球流量在三年内达到统计意义。研究结果是 用133氙气吸入技术和正电子发射进行的 体层摄影术。急性大麻中毒可增加脑血流量 右半球和扣带回的变化更为明显。 行为研究表明，许多神经心理学 异常，包括短期记忆损害，如用 数字符号替换测试。 在拟议的研究中，我们将使用正电子发射计算机断层扫描来评估区域脑血流在 THC或安慰剂输注后的再认和回忆激活任务 吸食大麻者。我们还将比较静息CBF与 神经心理测试。

DESCRIPTION: (Applicant's Abstract) Marijuana is the most commonly abused illegal drug in the United States. It is of particular concern that this drug is abused by large numbers of adolescents. Thus, the acute and chronic effects of marijuana and its active ingredients, including THC, are of considerable research interest and clinical significance. A number of investigators demonstrated alterations in brain function via neuropsychological testing in chronic marijuana users. With the recent advent of non-invasive techniques, it has become possible to measure cerebral blood flow (CBF) during cognitive testing in humans. In such activation studies, CBF serves as an index of regional brain function. All four available studies on CBF in chronic marijuana smokers found reduced global flow which reached statistical significance in three. Studies were conducted with the 133 xenon inhalation technique and positron emission tomography. Acute marijuana intoxication was found to increase CBF with more marked changes in the right hemisphere and in the cingulate gyrus. Behavioral studies have indicated a number of neuropsychological abnormalities, including impairment of short-term memory as measured with the digit symbol substitution test. In the proposed study we shall use PET to assess regional CBF changes during recognition and recall activation tasks following THC or placebo infusion in marijuana smokers. We shall also compare resting CBF with neuropsychological test.