Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel.
Department of Neuroscience, Brown University, Providence, RI 02912.
Proc Natl Acad Sci U S A. 2022 Jul 12;119(28):e2118192119. doi: 10.1073/pnas.2118192119. Epub 2022 Jul 6.
Studies with experimental animals have revealed a mood-regulating neural pathway linking intrinsically photosensitive retinal ganglion cells (ipRGCs) and the prefrontal cortex (PFC), involved in the pathophysiology of mood disorders. Since humans also have light-intensity-encoding ipRGCs, we asked whether a similar pathway exists in humans. Here, functional MRI was used to identify PFC regions and other areas exhibiting light-intensity-dependent signals. We report 26 human brain regions having activation that either monotonically decreases or monotonically increases with light intensity. Luxotonic-related activation occurred across the cerebral cortex, in diverse subcortical structures, and in the cerebellum, encompassing regions with functions related to visual image formation, motor control, cognition, and emotion. Light suppressed PFC activation, which monotonically decreased with increasing light intensity. The sustained time course of light-evoked PFC responses and their susceptibility to prior light exposure resembled those of ipRGCs. These findings offer a functional link between light exposure and PFC-mediated cognitive and affective phenomena.
研究动物实验已经揭示了一条与情绪障碍的病理生理学有关的、将内在感光视网膜神经节细胞（ipRGC）和前额叶皮层（PFC）联系起来的调节情绪的神经通路。由于人类也有光强度编码的 ipRGC，我们想知道是否在人类中存在类似的通路。在这里，功能磁共振成像被用于识别 PFC 区域和其他表现出光强度依赖性信号的区域。我们报告了 26 个人类大脑区域，它们的激活要么随着光强度单调减少，要么随着光强度单调增加。与光强度相关的激活发生在大脑皮层、不同的皮质下结构和小脑，包括与视觉图像形成、运动控制、认知和情绪相关的功能的区域。光抑制了 PFC 的激活，而 PFC 的激活随着光强度的增加而单调减少。光诱发的 PFC 反应的持续时间过程及其对先前光暴露的敏感性类似于 ipRGC 的反应。这些发现为光暴露与 PFC 介导的认知和情感现象之间提供了一个功能联系。
