Department of Neurology, University Hospital and Medical School of Geneva, Switzerland.
Neuroimage. 2013 Oct 1;79:42-51. doi: 10.1016/j.neuroimage.2013.04.074. Epub 2013 Apr 28.
The nicotinic system plays an important role in ordinary cognition, particularly in attention. The main nicotinic receptor in the human brain is the heteromeric α4β2 neuronal nicotinic acetylcholine receptor (nAChR), which is distributed throughout the brain, with an especially high density in the thalamus and brainstem. Despite the important role of α4β2 nAChRs in various physiological functions and pathological conditions, their distribution in the human cortex remains poorly characterized. We assessed the in vivo distribution of α4β2 nAChRs in the human cortex in a group of seven non-smoking healthy subjects, using 2-[(18)F]F-A-85380 PET and a volume-of-interest-based analysis. We showed that cortical nAChR density was highest in the insular and anterior cingulate cortices. In functional magnetic resonance imaging studies, these two cortical regions and the thalamus have been shown to be highly correlated during the resting state and various tasks. Here, we also directly assessed nAChR density in this cingulo-insular network as defined in an independent dataset using resting-state functional connectivity, and compared it to other control-related networks, to the default mode network as well as to sensory and motor networks. Receptor density was significantly higher in the cingulo-insular network. This network has been suggested to maintain a variety of foundational capacities fundamental to cognitive function. The demonstration of a high nAChR density in the insular and anterior cingulate cortices reflects a particular neurochemical organization of the cingulo-insular network, and suggests an important role of the nicotinic receptors in its functions.
尼古丁系统在普通认知中起着重要作用，特别是在注意力方面。人类大脑中的主要尼古丁受体是异源α4β2 神经元烟碱型乙酰胆碱受体 (nAChR)，它分布在整个大脑中，在丘脑和脑干中密度特别高。尽管α4β2 nAChRs 在各种生理功能和病理条件中起着重要作用，但它们在人类皮层中的分布仍知之甚少。我们在一组七名不吸烟的健康受试者中使用 2-[(18)F]F-A-85380 PET 和基于感兴趣区的分析评估了α4β2 nAChR 在人脑中的分布。我们发现皮层 nAChR 密度在岛叶和前扣带皮层最高。在功能磁共振成像研究中，这两个皮层区域和丘脑在静息状态和各种任务中显示出高度相关性。在这里，我们还直接评估了在独立数据集使用静息状态功能连接定义的扣带-岛叶网络中的 nAChR 密度，并将其与其他控制相关网络、默认模式网络以及感觉和运动网络进行了比较。受体密度在扣带-岛叶网络中显著更高。该网络被认为维持了各种对认知功能至关重要的基本能力。在岛叶和前扣带皮层中 nAChR 密度较高的发现反映了扣带-岛叶网络的特殊神经化学组织，并表明尼古丁受体在其功能中起着重要作用。
