Iyilikci Onur, Aydin E, Canbeyli R
Psychobiology Laboratory, Department of Psychology, Bogazici University, 34342 Bebek, Istanbul, Turkey.
Behav Brain Res. 2009 Oct 12;203(1):65-8. doi: 10.1016/j.bbr.2009.04.013. Epub 2009 Apr 18.
The present study investigated potential antidepressant effect of light exposure in the dark phase of a 12:12 L/D cycle on behavioral despair. In Exp.1, male Wistar rats were administered a single, 10 min broadband light pulse (1300lx) either 3h (ZT15) or 9h (ZT21) after dark onset (ZT12) and tested in two consecutive swim tests separated by 24 h. Photic stimulation at ZT21 but not ZT15 significantly reduced immobility in the second swim test relative to the first test compared to controls that were treated similarly except for light pulse administration (p<0.05). In Exp.2, groups were exposed to a single 10-min light pulse (1300lx) either in the blue or red end of the spectrum at ZT21 or were treated similarly except for photic exposure (controls). Exposure to blue light resulted in significantly reduced duration of immobility in the second swim test relative to that of the first test compared to the red light and control groups (p<0.05). The present findings suggest a critical role in the antidepressant effect of blue light stimulation for the melanopsin-containing ganglion cells in the retina that are sensitive to wavelengths in the blue but not red end of the visible spectrum.
本研究调查了在12:12光/暗循环的暗期进行光照对行为绝望的潜在抗抑郁作用。在实验1中，雄性Wistar大鼠在黑暗开始（ZT12）后3小时（ZT15）或9小时（ZT21）接受单次10分钟的宽带光脉冲（1300勒克斯）照射，并在间隔24小时的连续两次游泳测试中进行测试。与除光脉冲给药外接受类似处理的对照组相比，ZT21而非ZT15的光刺激在第二次游泳测试中相对于第一次测试显著降低了不动时间（p<0.05）。在实验2中，各实验组在ZT21时接受单次10分钟的光谱蓝端或红端的光脉冲（1300勒克斯）照射，或除光照外接受类似处理（对照组）。与红光组和对照组相比，蓝光照射导致第二次游泳测试中的不动时间相对于第一次测试显著缩短（p<0.05）。本研究结果表明，视网膜中对可见光谱蓝端而非红端波长敏感的含黑视蛋白神经节细胞在蓝光刺激的抗抑郁作用中起关键作用。
