Pilz Luísa K, Quiles Caroline L, Dallegrave Eliane, Levandovski Rosa, Hidalgo Maria Paz L, Elisabetsky Elaine
Ethnopharmacology Laboratory, Department of Pharmacology, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Chronobiology Laboratory, Department of Psychiatry and Legal Medicine, UFRGS, Porto Alegre, RS, Brazil.
Braz J Psychiatry. 2015 Jul-Sep;37(3):185-90. doi: 10.1590/1516-4446-2014-1454. Epub 2015 Mar 24.
Circadian disturbances common to modern lifestyles have been associated with mood disorders. Animal models that mimic such rhythm disturbances are useful in translational research to explore factors contributing to depressive disorders. This study aimed to verify the susceptibility of BALB/c, C57BL/6N, and CF1 mice to photoperiod changes.
Thermochron iButtons implanted in the mouse abdomen were used to characterize temperature rhythms. Mice were maintained under a 12:12 h light-dark (LD) cycle for 15 days, followed by a 10:10 h LD cycle for 10 days. Cosinor analysis, Rayleigh z test, periodograms, and Fourier analysis were used to analyze rhythm parameters. Paired Student's t test was used to compare temperature amplitude, period, and power of the first harmonic between normal and shortened cycles.
The shortened LD cycle significantly changed temperature acrophases and rhythm amplitude in all mouse strains, but only BALB/c showed altered period.
These findings suggest that BALB/c, the preferred strain for stress-induced models of depression, should also be favored for exploring the relationship between circadian rhythms and mood. Temperature rhythm proved to be a useful parameter for characterizing rhythm disruption in mice. Although disruption of temperature rhythm has been successfully documented in untethered mice, an evaluation of desynchronization of other rhythms is warranted.
现代生活方式常见的昼夜节律紊乱与情绪障碍有关。模拟此类节律紊乱的动物模型在转化研究中有助于探索导致抑郁症的因素。本研究旨在验证BALB/c、C57BL/6N和CF1小鼠对光周期变化的易感性。
将植入小鼠腹部的温度记录器用于表征温度节律。小鼠先在12:12小时明暗（LD）循环下饲养15天，随后在10:10小时LD循环下饲养10天。采用余弦分析、瑞利z检验、周期图和傅里叶分析来分析节律参数。配对学生t检验用于比较正常周期和缩短周期之间的温度振幅、周期和一次谐波功率。
缩短的LD循环显著改变了所有小鼠品系的温度峰相位和节律振幅，但只有BALB/c小鼠的周期发生了改变。
这些发现表明，BALB/c作为应激诱导抑郁症模型的首选品系，在探索昼夜节律与情绪之间的关系时也应受到青睐。温度节律被证明是表征小鼠节律紊乱的一个有用参数。尽管在未系绳小鼠中已成功记录到温度节律的紊乱，但仍有必要评估其他节律的去同步化情况。
