Mice exposed to circadian disruption (CD) light conditions have altered activity rhythms. (
A) Picture of the custom-built infrared motion sensor (PIR), showing (
above) the sensor as encased in a 3D-printed plastic shell and (
below) removed from the case showing the circuit board and components. (
B) Representative control light (CL) cycle (
black outline), with lights on (
pale yellow shading) at 6 AM and lights off (
navy blue shading) at 6 PM, and CD light cycle (
red outline), with light inversions twice weekly (note that this is the same schedule as shown in
Figure 1, but plotted with different start time). (
C) Representative single-plotted actograms from 3 cages of female mice exposed to CL over a 6-day period, with
vertical black lines indicating activity and each row representing a 24-hour period. (
D) Representative single-plotted actograms from 3 cages of female mice exposed to CD over a 6-day period, with
black lines indicating activity and each row a 24-hour period. (
E) Representative actograms from running wheels of females exposed to CD over a 15-day period, with
black lines indicating activity and each row a 24-hour period. (
F) Intradaily stability (t = 6.77, df = 4,
P = 0.003), (
G) intradaily variability (t = 0.40, df = 4,
P = 0.71), and (
H) relative amplitude (t = 3.52, df = 4,
P = 0.025) as calculated from the representative actograms in
C and
D, presented as mean ± SEM and analyzed with student's 2-tailed unpaired
t-tests, *
P < 0.05 and **
P < 0.01.