Koch Kathrin, Wagner Gerd, Schachtzabel Claudia, Schultz C Christoph, Güllmar Daniel, Reichenbach Jürgen R, Sauer Heinrich, Zimmer Claus, Schlösser Ralf G M
Department of Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany; Department of Psychiatry and Psychotherapy, Jena University Hospital, Philosophenweg 3, 07743 Jena, Germany.
Hum Brain Mapp. 2014 Apr;35(4):1469-76. doi: 10.1002/hbm.22284. Epub 2013 Apr 24.
Individual responsiveness to rewards or rewarding stimuli may affect various domains of normal as well as pathological behavior. The ventral striatum/nucleus accumbens (NAcc) constitutes a key brain structure in the regulation of reward-appetitive behavior. It remains unclear, however, to which extent individual reward-related BOLD response in the NAcc is dependent on individual characteristics of connecting white matter fiber tracts. Using tract-based spatial statistics (TBSS) and statistical parametric mapping (SPM) this combined DTI - fMRI study investigated this question by correlating NAcc BOLD signal upon receipt of a monetary reward with different white matter characteristics (FA, axial diffusivity, radial diffusivity). The results show that increased integrity of white matter as assessed by FA in the cingulate and corpus callosum, the inferior fronto-occipital fasciculus, the anterior thalamic radiation and the anterior limb of the internal capsule was positively correlated with reward-related activation in the NAcc. There were no negative correlations as well as no significant results regarding axial and radial diffusivity. These findings indicate that microstructural properties of fiber tracts connecting, amongst others, the cortex with the striatum may influence intensity of reward-related responsiveness of the ventral striatum by constraining or increasing efficiency in information transfer within relevant circuitries involved in processing of reward.
个体对奖励或奖励性刺激的反应性可能会影响正常及病理行为的各个领域。腹侧纹状体/伏隔核（NAcc）是调节奖励性食欲行为的关键脑结构。然而，尚不清楚NAcc中与奖励相关的个体血氧水平依赖（BOLD）反应在多大程度上取决于连接白质纤维束的个体特征。本DTI - fMRI联合研究使用基于纤维束的空间统计学（TBSS）和统计参数映射（SPM），通过将获得金钱奖励时的NAcc BOLD信号与不同的白质特征（分数各向异性（FA）、轴向扩散率、径向扩散率）进行关联，来研究这个问题。结果表明，扣带回和胼胝体、额枕下束、丘脑前辐射和内囊前肢中FA评估的白质完整性增加与NAcc中与奖励相关的激活呈正相关。关于轴向扩散率和径向扩散率，既没有负相关，也没有显著结果。这些发现表明，连接皮层与纹状体等的纤维束的微观结构特性可能通过限制或提高参与奖励处理的相关回路内的信息传递效率，来影响腹侧纹状体与奖励相关的反应强度。
