School of Medicine
Behavioral Medicine and Psychiatry
Light has substantial influences on the physiology and behavior of most laboratory animals. As such, lighting conditions within animal rooms are potentially significant, and often underappreciated variables within experiments. Disruption of the light/dark cycle, primarily by exposing animals to light at night (LAN), disturbs biological rhythms and has widespread physiological consequences due to mechanisms such as melatonin suppression, sympathetic stimulation, and altered circadian clock gene expression. Thus, attention to the lighting environment of laboratory animals and maintaining consistency of a light/dark cycle is imperative for study reproducibility. Light intensity as well as wavelength, photoperiod, and timing are all important variables. Although modern rodent facilities are designed to facilitate appropriate light cycling, there are simple ways to modify rooms to prevent extraneous light exposure during the dark period. Attention to lighting conditions of laboratory animals by both researchers and research care staff ensures best practices for maintaining animal welfare, as well as reproducibility of research results.
Digital Commons Citation
Emmer, Kathryn M.; Russart, Kathryn L. G.; Walker, William H. II; Nelson, Randy J.; and DeVries, A. Courtney, "Effects of light at night on laboratory animals and research outcomes" (2018). Clinical and Translational Science Institute. 902.
Emmer KM, Russart KLG, Walker WH, Nelson RJ, DeVries AC. Effects of light at night on laboratory animals and research outcomes. Behavioral Neuroscience. 2018;132(4):302-314. doi:10.1037/bne0000252