<i>Per1</i> mutation enhances masking responses in mice

Light can restrict the activity of an animal to a diurnal or nocturnal niche by synchronizing its endogenous clock (entrainment) which controls the sleep wake cycle. Light can also directly change an animal’s activity level (masking). In mice, high illumination levels decrease activity, i.e. negative masking occurs. To investigate the role of core circadian clock genes <i>Per1</i> and <i>Per2</i> in masking, we used a 5-day behavioral masking protocol consisting of 3 h pulses of light given in the night at various illuminances (4–5 lux, 20 lux and 200 lux). Mice lacking the <i>Per1</i> gene had decreased locomotion in the presence of a light pulse compared to wild-type, <i>Per2</i> and <i>Per1 Per2</i> double mutant mice. <i>Per2</i> single mutant and <i>Per1 Per2</i> double mutant mice did not show significantly different masking responses compared to wild-type controls. This suggests that <i>Per1</i> suppresses negative masking responses in mice.

光线可通过同步动物的内生生物钟（节律同步化，entrainment），将其活动限制在昼行或夜行生态位，而该内生生物钟正是调控睡眠-觉醒周期的核心机制。光线还可直接改变动物的活动水平，该效应被称为掩蔽效应（masking）。在小鼠中，高光照水平会抑制其活动，即出现负向掩蔽效应。为探究核心生物钟基因Per1（Period 1）与Per2（Period 2）在掩蔽效应中的作用，本研究采用为期5天的行为学掩蔽实验范式：于夜间以不同光照强度（4~5勒克斯、20勒克斯及200勒克斯）给予3小时的光脉冲刺激。与野生型小鼠、Per2单基因敲除小鼠及Per1 Per2双基因敲除小鼠相比，Per1基因敲除小鼠在光脉冲刺激下的运动活性显著降低。Per2单基因敲除小鼠与Per1 Per2双基因敲除小鼠的掩蔽反应与野生型对照组相比无显著差异。上述实验结果表明，Per1基因可抑制小鼠的负向掩蔽反应。

搜集汇总

背景与挑战

背景概述

该数据集研究小鼠中Per1基因突变对光掩蔽反应的影响，通过行为实验发现Per1缺失增强负掩蔽反应（即光照下活动减少），而Per2基因突变无显著作用。这揭示了Per1在调节小鼠光直接行为响应中的关键抑制角色，涉及昼夜节律和基因功能领域。