Nonvisual Responses to Light Exposure in the Human Brain during the Circadian Night

@article{citeulike:1367059, abstract = {The brain processes light information to visually represent the environment but also to detect changes in ambient light level. The latter information induces non-image-forming responses and exerts powerful effects on physiology such as synchronization of the circadian clock and suppression of melatonin [, and ]. In rodents, irradiance information is transduced from a discrete subset of photosensitive retinal ganglion cells via the retinohypothalamic tract to various hypothalamic and brainstem regulatory structures including the hypothalamic suprachiasmatic nuclei, the master circadian pacemaker [, and ]. In humans, light also acutely modulates alertness [ and ], but the cerebral correlates of this effect are unknown. We assessed regional cerebral blood flow in 13 subjects attending to auditory and visual stimuli in near darkness following light exposures (>8000 lux) of different durations (0.5, 17, 16.5, and 0 min) during the biological night. The bright broadband polychromatic light suppressed melatonin and enhanced alertness. Functional imaging revealed that a large-scale occipito-parietal attention network, including the right intraparietal sulcus, was more active in proportion to the duration of light exposures preceding the scans. Activity in the hypothalamus decreased in proportion to previous illumination. These findings have important implications for understanding the effects of light on human behavior.}, author = {Perrin, Fabien and Peigneux, Philippe and Fuchs, Sonia and Verhaeghe, Stephane and Laureys, Steven and Middleton, Benita and Degueldre, Christian and Del Fiore, Guy and Vandewalle, Gilles and Balteau, Evelyne and Poirrier, Robert and Moreau, Vincent and Luxen, Andre and Maquet, Pierre and Dijk, Derk-Jan }, citeulike-article-id = {1367059}, journal = {Current Biology}, keywords = {circadian}, month = {October}, number = {20}, pages = {1842--1846}, posted-at = {2007-06-06 01:59:06}, priority = {2}, title = {Nonvisual Responses to Light Exposure in the Human Brain during the Circadian Night}, url = {http://www.sciencedirect.com/science/article/B6VRT-4DMW0C4-T/2/c8afda8c5c996b8ddc3b415782257225}, volume = {14}, year = {2004} }

TY - JOUR ID - citeulike:1367059 L3 - citeulike-article-id:1367059 TI - Nonvisual Responses to Light Exposure in the Human Brain during the Circadian Night JF - Current Biology VL - 14 IS - 20 SP - 1842 EP - 1846 N2 - The brain processes light information to visually represent the environment but also to detect changes in ambient light level. The latter information induces non-image-forming responses and exerts powerful effects on physiology such as synchronization of the circadian clock and suppression of melatonin [, and ]. In rodents, irradiance information is transduced from a discrete subset of photosensitive retinal ganglion cells via the retinohypothalamic tract to various hypothalamic and brainstem regulatory structures including the hypothalamic suprachiasmatic nuclei, the master circadian pacemaker [, and ]. In humans, light also acutely modulates alertness [ and ], but the cerebral correlates of this effect are unknown. We assessed regional cerebral blood flow in 13 subjects attending to auditory and visual stimuli in near darkness following light exposures (>8000 lux) of different durations (0.5, 17, 16.5, and 0 min) during the biological night. The bright broadband polychromatic light suppressed melatonin and enhanced alertness. Functional imaging revealed that a large-scale occipito-parietal attention network, including the right intraparietal sulcus, was more active in proportion to the duration of light exposures preceding the scans. Activity in the hypothalamus decreased in proportion to previous illumination. These findings have important implications for understanding the effects of light on human behavior. KW - circadian AU - Perrin, Fabien AU - Peigneux, Philippe AU - Fuchs, Sonia AU - Verhaeghe, Stephane AU - Laureys, Steven AU - Middleton, Benita AU - Degueldre, Christian AU - Del Fiore, Guy AU - Vandewalle, Gilles AU - Balteau, Evelyne AU - Poirrier, Robert AU - Moreau, Vincent AU - Luxen, Andre AU - Maquet, Pierre AU - Dijk, Derk-Jan PY - 2004/10/26/ UR - http://www.sciencedirect.com/science/article/B6VRT-4DMW0C4-T/2/c8afda8c5c996b8ddc3b415782257225 ER -