Department of Psychology, University of Minnesota , Elliott Hall, Minneapolis, MN , USA and.
Am J Drug Alcohol Abuse. 2013 Nov;39(6):403-13. doi: 10.3109/00952990.2013.848211.
Addiction is a complex phenotype, though it consistently includes characteristics of impulsivity. A number of brain regions are suggested to be involved in cocaine addiction, including the insula, which serves diverse functions including interoceptive awareness and integration of neural signals from sensory, subcortical and frontal regions. Malfunction of this integration links impulsive behavior to the insula.
This study examines intrinsic connectivity of the insula in chronic cocaine users to investigate abnormal insular circuitry, its role in cocaine addiction, and relationships to measure of impulsivity.
Cocaine-dependent individuals (n = 33) and healthy controls (n = 32) completed a resting-state fMRI scan. An intrinsic connectivity network (ICN) approach generated metrics of mean network connectivity and inter-network connectivity from fMRI data. Metrics pertaining to ICNs involving insula and other structures repeatedly involved in addiction (e.g. striatum) were selected for analysis, which included the capacity to discriminate groups. Relationships between group discriminating connectivity metrics and behavioral impulsivity were examined.
Models demonstrated group prediction accuracy up to 75%. Accuracy of 69% was obtained by a parsimonious model of six inter-network connectivity metrics. The inter-network connectivity between an ICN involving the anterior insula and ACC, and an ICN involving the striatum, was significantly weaker in cocaine users relative to controls. The degree of reduced inter-network connectivity was significantly related to greater non-planning impulsivity in cocaine users.
Aberrant insula-derived intrinsic connectivity patterns are observed in cocaine users and include dysfunctions in insula to striatal connectivity, which is furthermore linked to increased impulsivity pertaining to forethought.
成瘾是一种复杂的表型，尽管它始终包括冲动性的特征。许多脑区被认为与可卡因成瘾有关，包括脑岛，它具有多种功能，包括内感受意识和整合来自感觉、皮质下和额叶区域的神经信号。这种整合的功能障碍将冲动行为与脑岛联系起来。
本研究通过检查慢性可卡因使用者脑岛的内在连通性，来研究异常的脑岛回路，它在可卡因成瘾中的作用，以及与冲动性测量的关系。
可卡因依赖者（n=33）和健康对照者（n=32）完成了静息状态 fMRI 扫描。内在连通性网络（ICN）方法从 fMRI 数据中生成了网络连通性和网络间连通性的平均度量。选择与脑岛和其他结构有关的涉及成瘾的 ICN 度量（例如纹状体）进行分析，包括区分组别的能力。还检查了组间区分连通性度量与行为冲动性之间的关系。
模型显示出高达 75%的组预测准确性。通过涉及前脑岛和 ACC 的 ICN 与涉及纹状体的 ICN 之间的六个网络间连通性度量的简约模型，获得了 69%的准确率。与对照组相比，可卡因使用者中涉及前脑岛和 ACC 的 ICN 与涉及纹状体的 ICN 之间的网络间连通性明显较弱。可卡因使用者的网络间连通性降低程度与非计划性冲动性增加显著相关。
在可卡因使用者中观察到异常的脑岛源性内在连通性模式，包括脑岛与纹状体连通性的功能障碍，并且与前瞻性冲动性增加有关。
