Biomedical Imaging Technology Center, Department of Biomedical Engineering, Emory University & Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
Neurotoxicol Teratol. 2009 Nov-Dec;31(6):342-8. doi: 10.1016/j.ntt.2009.08.005. Epub 2009 Aug 21.
While prenatal cocaine exposure (PCE) has been associated with arousal dysregulation and attentional impairments in both human and animal studies, the neurobiological bases of these teratogenic effects have not been well characterized. In the current study, we report functional neuroimaging observations of these effects in exposed youth. Using functional magnetic resonance imaging (fMRI), we embedded task-irrelevant emotional distracters in a working memory task to examine the interaction of emotional arousal and memory in 33 PCE and 23 non-exposed adolescents. Though with similar behavioral performance, the two groups exhibited different activation patterns associated with emotion-memory interactions. On the one hand, higher memory load attenuated emotion-related amygdala activation in controls but not in the exposed adolescents; on the other hand, prefrontal activation associated with memory load decreased in the presence of emotional distraction in the controls but increased in the exposed group. These group interaction differences suggest neurobiological substrates for arousal-associated neuronal alterations related to prenatal cocaine exposure. Consistent with previous findings in behavioral and physiological studies, the present neuroimaging data provided more in-depth evidence supporting the view that PCE has significant long-term teratogenic effect on arousal regulation system.
虽然产前可卡因暴露 (PCE) 已在人类和动物研究中与觉醒失调和注意力损伤相关，但这些致畸作用的神经生物学基础尚未得到很好的描述。在当前的研究中，我们报告了这些暴露于可卡因的年轻人的功能性神经影像学观察结果。使用功能磁共振成像 (fMRI)，我们在一项工作记忆任务中嵌入了与任务无关的情绪干扰，以检查 33 名 PCE 青少年和 23 名非暴露青少年的情绪唤醒和记忆之间的相互作用。尽管行为表现相似，但两组表现出与情绪-记忆相互作用相关的不同激活模式。一方面，更高的记忆负荷减弱了对照组中与情绪相关的杏仁核激活，但在暴露组中没有；另一方面，在对照组中存在情绪干扰时，与记忆负荷相关的前额叶激活减少，但在暴露组中增加。这些组间交互差异表明，与产前可卡因暴露相关的觉醒相关神经元改变存在神经生物学基础。与行为和生理研究中的先前发现一致，本神经影像学数据提供了更深入的证据，支持 PCE 对觉醒调节系统具有重大长期致畸作用的观点。
