Matochik John A, London Edythe D, Eldreth Dana A, Cadet Jean-Lud, Bolla Karen I
Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
Neuroimage. 2003 Jul;19(3):1095-102. doi: 10.1016/s1053-8119(03)00244-1.
Cocaine abusers exhibit impairment of executive cognitive functions that are mediated by the frontal cortex. This work tested for structural (i.e., tissue composition) abnormalities that may underlie such performance deficits. Research participants were cocaine abusers (n = 14) abstinent for 20 days and a non-drug-using comparison group (n = 11), who underwent magnetic resonance imaging (T1-weighted scans of the brain). Gray matter and white matter tissue densities were determined using voxel-based morphometry with small volume correction based on a priori hypotheses derived from functional imaging of the same subjects. Cocaine abusers had significantly lower gray matter tissue density than did the non drug users in 10 of 13 small volumes analyzed in the frontal cortex [bilateral anterior cingulate gyrus (infragenual and perigenual regions) and medial orbitofrontal cortex and the lateral orbitofrontal cortex and middle/dorsal cingulate gyrus in the right hemisphere]. No group differences were found in white matter density of the frontal cortex. These results extend our previous findings of defective frontal cortical activation (indexed by cerebral blood flow) in cocaine abusers to include abnormalities in gray matter tissue density in the same frontal cortical regions.
可卡因滥用者表现出由额叶皮层介导的执行认知功能受损。这项研究测试了可能是这种表现缺陷基础的结构（即组织成分）异常。研究参与者包括20天未使用可卡因的可卡因滥用者（n = 14）和非吸毒对照组（n = 11），他们接受了磁共振成像（大脑的T1加权扫描）。基于对同一受试者功能成像得出的先验假设，使用基于体素的形态测量法并进行小体积校正来确定灰质和白质组织密度。在额叶皮层分析的13个小体积区域中的10个区域，可卡因滥用者的灰质组织密度显著低于非吸毒者[双侧前扣带回（膝下和膝周区域）、内侧眶额皮层、外侧眶额皮层以及右半球的中/背侧扣带回]。额叶皮层的白质密度未发现组间差异。这些结果将我们之前关于可卡因滥用者额叶皮层激活缺陷（以脑血流量为指标）的发现扩展到包括同一额叶皮层区域灰质组织密度异常。
