Melanopsin bistability impinges on higher order cognitive brain function

摘要: Introduction: Light strongly stimulates human alertness and cognition, presumably through intrinsically-photosensitive retinal ganglion cells (ipRGCs) that express melanopsin. However, direct evidence for the involvement of ipRGCs in stimulating cognition normal individuals has not yet been reported. Recent vitro vivo studies suggest melanopsin is bistable light sensitivity modulated by prior exposure. According to this hypothesis, pre-exposure longer but shorter wavelength increase photics responsiveness Here we tested whether immediate history modulates subsequent impact on cognitive brain function, modulation consistent with bistability properties. Methods: Sixteen participants underwent 3 consecutive fMRI sessions during which they were exposed monochromatic green (511nm) while performing auditory working memory 3-back 0-back tasks. One hour each session, 10min orange (589nm), or blue (461nm) light. We computed difference between tasks isolate executive responses compared influence these sessions. Results: Prior exposure orange, as light, increased bilaterally superior frontal gyrus dorsolateral prefrontal cortex right ventrolateral cortex. Furthermore, green, left The remaining comparisons (orange>green; green>orange; blue>orange; blue>green) led no significant response changes. Conclusion: Although performed same task under condition, influenced areas agreement hypotheses bistability. Our data favor a role melanopsin-expressing responses. Melanopsin may therefore confer “photic memory” cognition. Support:FNRS(Belgium),FMRE,ULg