Effect of light colour temperature and intensity on τhε behaviour of male C57CL/6J mice

Abstract

Light is an important environmental factor affecting laboratory animals' well-being but still there is a range of light parameters in animal research facilities that need further study. Behavioural testing was conducted to study the impact of different conditions of light colour temperature and intensity (4000K, 60lx; 4000K, 30lx; 2500K, 60lx; 2500K, 30lx) on rodents' behaviour. 24 C57BL/6J mice were subjected to marble burying, open field and elevated plus-maze test to detect effects of lighting on spontaneous behaviour, locomotor activity and anxiety-like behaviour, respectively. Data, as normally distributed, were analysed using analysis of variance (ANOVA). Mice exposed to cool light (4000K) of high intensity (60lx) exhibited the highest level of anxiety-like behaviour in the elevated plus-maze test in comparison to the groups of mice exposed to the other lighting conditions, while those exposed to warm light (2500K) of low intensity (30lx) were the less anxious, since a main effect of colour temperature (P<0.05) as well as a main effect of intensity (P<0.05) were detected. However, spontaneous repetitive behaviour and locomotion seemed to be unaffected by both light parameters. In conclusion, light colour temperature of either 4000 or 2500K combined with intensity of either 60 or 30lx did not affect spontaneous behaviours and locomotor activity levels, but mice exposed to light colour temperature of 4000K and intensity of 60lx were more stressed, which is indicative of an undesirable, more anxiogenic environment for the mice.