Effects of a fire alarm strobe light on fecal corticosterone metabolite concentrations in mice

The type and location of fire alarms are important considerations in animal facility design. The Guide for the Care and Use of Laboratory Animals recommends minimizing animal exposure to such alarms. Nevertheless, it is often necessary to maintain fire alarms within animal housing or procedural areas. The authors exposed male mice to the flashing strobe light component of a standard fire alarm and evaluated mouse fecal corticosterone concentration, which is known to be an indicator of stress. Mice were exposed to the strobe light for 5 min during either the light or the dark phase of the light:dark cycle. The authors collected fecal samples every 6 h for 24 h before exposing mice to the alarm and every 6 h for 24 h after exposure. Fecal samples taken before exposure (baseline samples) showed a normal circadian pattern of corticosterone metabolite excretion. In fecal samples taken after mice were exposed to the fire alarm, metabolite concentrations did not significantly differ from baseline concentrations over time.