Department of Neuroscience, University of Parma, Parma, Italy.
Brain Res Bull. 2012 Feb 10;87(2-3):205-11. doi: 10.1016/j.brainresbull.2011.11.021. Epub 2011 Dec 7.
A number of neuroimaging studies have shown that drug addiction is associated with morphological differences in several brain areas, including orbito-frontal and limbic structures. Most of these studies have investigated patients with addiction to cocaine. The neurobiological mechanisms which play a role in drug addiction are not fully understood, however, and the causal factors remain under investigation. The present study investigated morphological differences between patients with history of cocaine (N=14) and heroin (N=24) abuse and healthy matched controls (N=24). A 3D T1W MRI scan was acquired for all participants and the grey matter images of each patient group compared with those of controls. A direct comparison of the two addiction groups was also carried out. When compared with controls cocaine dependent patients had lower grey matter values in the left middle occipital gyrus, right putamen and insula, whereas heroin abusers had lower grey matter values in the right insula. The direct comparison between the two addiction groups showed that cocaine abusers had less grey matter in the right posterior cingulate, medio-temporal and cerebellar regions, whereas heroin abusers showed less grey matter in parietal regions on both sides, including postcentral gyrus and inferior parietal lobule. Reduced right posterior insular cortex was commonly found in both cocaine and heroin dependent patients. This morphological difference might represent a structural marker of addiction, which is independent of the discrete regional effects of each psychotropic substance of abuse, and might constitute a possible neurobiological vulnerability or diathesis to addiction. Equally, the discrete structural differences emerging from the direct comparison of cocaine and heroin abusers might reflect the effects of differential drug binding in the brain and/or express a form of neurobiological vulnerability which might explain individual drug choice.
许多神经影像学研究表明，药物成瘾与包括眶额和边缘结构在内的几个大脑区域的形态差异有关。这些研究大多针对可卡因成瘾患者进行。然而，药物成瘾的神经生物学机制尚未完全了解，因果因素仍在研究中。本研究调查了有可卡因（N=14）和海洛因（N=24）滥用史的患者与健康匹配对照者（N=24）之间的形态差异。所有参与者均进行了 3D T1W MRI 扫描，并将每个患者组的灰质图像与对照组进行比较。还对这两个成瘾组进行了直接比较。与对照组相比，可卡因依赖者左侧中枕叶、右侧壳核和脑岛的灰质值较低，而海洛因滥用者右侧脑岛的灰质值较低。对这两个成瘾组的直接比较显示，可卡因滥用者右侧后扣带回、中颞叶和小脑区域的灰质较少，而海洛因滥用者两侧顶叶区域的灰质较少，包括中央后回和下顶叶。右后岛叶皮质普遍减少，可卡因和海洛因依赖者均如此。这种形态差异可能代表成瘾的结构标志物，与每种精神药物滥用的离散区域效应无关，可能构成成瘾的潜在神经生物学易感性或素质。同样，可卡因和海洛因滥用者直接比较中出现的离散结构差异可能反映了大脑中药物结合的差异效应，或表达一种可能解释个体药物选择的神经生物学易感性。
