Smith Jared B, Liang Zhifeng, Watson Glenn D R, Alloway Kevin D, Zhang Nanyin
Department of Engineering Science and Mechanics, Penn State University, University Park, PA, 16802, USA.
Center for Neural Engineering, Penn State University, W-316 Millennium Science Complex, University Park, PA, 16802, USA.
Brain Struct Funct. 2017 Jul;222(5):2041-2058. doi: 10.1007/s00429-016-1323-9. Epub 2016 Oct 6.
The claustrum is a brain region whose function remains unknown, though many investigators suggest it plays a role in conscious attention. Resting-state functional magnetic resonance imaging (RS-fMRI) has revealed how anesthesia alters many functional connections in the brain, but the functional role of the claustrum with respect to the awake versus anesthetized states remains unknown. Therefore, we employed a combination of seed-based RS-fMRI and neuroanatomical tracing to reveal how the anatomical connections of the claustrum are related to its functional connectivity during quiet wakefulness and the isoflurane-induced anesthetic state. In awake rats, RS-fMRI indicates that the claustrum has interhemispheric functional connections with the mediodorsal thalamus (MD) and medial prefrontal cortex (mPFC), as well as other known connections with cortical areas that correspond to the connections revealed by neuroanatomical tracing. During deep isoflurane anesthesia, the functional connections of the claustrum with mPFC and MD were significantly attenuated, while those with the rest of cortex were not significantly altered. These changes in claustral functional connectivity were also observed when seeds were placed in mPFC or MD during RS-fMRI comparisons of the awake and deeply anesthetized states. Collectively, these data indicate that the claustrum has functional connections with mPFC and MD-thalamus that are significantly lessened by anesthesia.
屏状核是一个功能未知的脑区，不过许多研究人员认为它在意识注意力方面发挥作用。静息态功能磁共振成像（RS-fMRI）已揭示麻醉如何改变大脑中的许多功能连接，但屏状核在清醒状态与麻醉状态下的功能作用仍不清楚。因此，我们采用基于种子点的RS-fMRI和神经解剖示踪相结合的方法，来揭示在安静清醒状态和异氟烷诱导的麻醉状态下，屏状核的解剖连接如何与其功能连接相关。在清醒大鼠中，RS-fMRI显示屏状核与背内侧丘脑（MD）和内侧前额叶皮质（mPFC）存在半球间功能连接，以及与皮质区域的其他已知连接，这些连接与神经解剖示踪所揭示的连接相对应。在深度异氟烷麻醉期间，屏状核与mPFC和MD的功能连接显著减弱，而与其余皮质的连接未发生显著改变。在对清醒和深度麻醉状态进行RS-fMRI比较时，当种子点置于mPFC或MD中时，也观察到了屏状核功能连接的这些变化。总体而言，这些数据表明屏状核与mPFC和丘脑MD存在功能连接，而麻醉会使这些连接显著减少。
