Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands.
Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.
J Biol Rhythms. 2022 Apr;37(2):216-221. doi: 10.1177/07487304221074995. Epub 2022 Feb 8.
Sleep deprivation reduces the response of neuronal activity in the suprachiasmatic nucleus (SCN) and the phase shift in circadian behaviour to phase shifting light pulses, and thus seems to impair the adaptation of the circadian clock to the external light-dark cycle. The question remains where in the pathway of light input to the SCN the response is reduced. We therefore investigated whether the electroretinogram (ERG) changes after sleep deprivation in wild-type mice and in mutant male mice. We found that the ERG is clearly affected by the mutations, but that the ERG after sleep deprivation does not differ from the baseline response. The difference between wild-type and mutant is in accordance with the lack of functional rod and melanopsin in the retina of the mutant mice. We conclude that the decrease in light responsiveness of the SCN after sleep deprivation is probably not caused by changes at the retinal level, but rather at the postsynaptic site within the SCN, reflecting affected neurotransmitter signalling.
睡眠剥夺会降低视交叉上核（SCN）神经元活动的反应性和昼夜节律行为的相移光脉冲，从而似乎损害了生物钟对外部明暗周期的适应。问题仍然是在光输入到 SCN 的途径中，反应性降低在哪里。因此，我们研究了睡眠剥夺后在野生型小鼠和 突变雄性小鼠中是否会改变视网膜电图（ERG）。我们发现 ERG 明显受到 突变的影响，但睡眠剥夺后的 ERG 与基线反应没有差异。野生型和突变型之间的差异与突变型小鼠视网膜中功能型视杆细胞和黑视蛋白的缺乏相一致。我们得出结论，睡眠剥夺后 SCN 对光反应性的降低可能不是由视网膜水平的变化引起的，而是由 SCN 内突触后部位的变化引起的，反映了受影响的神经递质信号传递。
