HUMAN BRAIN FUNCTION AND DRUG ABUSE

该项目旨在识别大脑中的异常 导致药物依赖的功能，并提供线索 在开发新的治疗方式方面。我们的战略已经 包括评估可卡因的渴求和 大脑新陈代谢通过使用 [F-18]氟脱氧葡萄糖正电子发射断层扫描(PET) 方法和脑电(EEG)觉醒体征； 比较大脑结构大小的差异，因为它们相关 对物质滥用者的影响；以及确定 尼古丁对大脑功能的影响。一种高分辨率的磁共振 25例前额叶体积的影像研究 多物质滥用者和14名正常志愿者发现 前额叶的总体积在 物质滥用者。这一赤字后来被描述为 灰质体积的减少，但不是白质。这些结果 表明前额叶发育不良和/或萎缩 伴随着多种物质的滥用，是一项关于 前额叶皮质功能。前额叶的结构性赤字 吸毒量可能与吸毒者在 这是一项对人类眼眶前额损伤敏感的任务。这项任务 (赌博任务)要求主体权衡短期收益 以防范长期损失。曾接受治疗的吸毒者(n=30) 在这项任务上明显比对照组(n=24)差。论 另一方面，多药滥用者和吸毒者之间没有差别 威斯康星州卡片分类任务的控制，一种标准 额叶皮质功能的神经心理测试，这是 对背外侧前额叶皮质损伤敏感。这些 数据表明，多药滥用可能与功能性 前额叶皮质特定部分的缺陷。一项新的研究是 评估尼古丁对大脑功能的影响，通过 宠物用[O-15]H2O。局部脑血流激活 在一项工作记忆任务中评估戒酒12小时(12小时) 尼古丁依赖吸烟者和12名非依赖对照。在……里面 尼古丁依赖吸烟者，记忆力表现似乎 由与对照组不同的神经底物介导， 这表明长期接触尼古丁会改变认知能力 为记忆服务的策略或神经系统。地区性 工作记忆任务执行期间的激活(N-BACK 在对照组中，尼古丁增加了)，但在吸烟者中没有增加。

This project aims to identify abnormalities in brain function that contribute to dependence on drugs, and to offer leads in developing new treatment modalities. Our strategies have included evaluating the relationship between cocaine craving and brain metabolism as measured using the [F-18]flurodeoxyglucose-positron emission tomography (PET) method and electroencephalographic (EEG) signs of arousal; comparing differences in the size of brain structures as they relate to substance abusers; and determining the cognitive effects of nicotine on brain function. A high-resolution magnetic resonance imaging study, measuring prefrontal lobe volumes in 25 polysubstance abusers and 14 normal volunteers, found that the total volume of the prefrontal lobe was significantly smaller in substance abusers. This deficit was subsequently characterized as a reduction in the volume of gray but not white matter. These results indicate that hypoplasia and/or atrophy in the prefrontal lobe accompanies polysubstance abuse and were the basis for a study of prefrontal cortical function. The structural deficit in prefrontal volume may be related to the poor performance of drug abusers on a task that is sensitive to orbitofrontal damage in humans. This task (Gambling Task) requires that the subject balance short term gains against long term losses. Polydrug abusers (n=30) performed significantly more poorly on this task than controls (n =24). On the other hand, there was no difference between polydrug abusers and controls on the Wisconsin Card Sorting Task, a standard neuropsychological test of frontal cortical function, which is sensitive to damage of the dorsolateral prefrontal cortex. These data imply that polydrug abuse may be associated with functional deficits in specific portions of the prefrontal cortex. A new study is evaluating the effects of nicotine on brain function, as measured by PET with [O-15]H2O. Regional cerebral blood flow activation during a working memory task was assessed in 12 abstinent (12 h) nicotine-dependent smokers and 12 non-dependent controls. In nicotine-dependent smokers, memory performance seemed to be mediated by different neural substrates than those in controls, suggesting that chronic exposure to nicotine alters cognitive strategies or neural systems subserving memory. Regional activation during performance of a working memory task (N-Back test) was increased by nicotine in controls, but not in smokers.