Forced desynchrony disrupts the plasma corticosterone rhythm.

<p>A) Double-plotted locomotor activity of a representative forced desynchronized rat. Grey bars represent locomotor activity; double diagonal bands indicate the time of lights-on (<i>for box “C”</i>) or time of lights-off (<i>for box “D”</i>); dashed diagonal lines indicate the onset of dmSCN-associated locomotor activity bout with the angle set to match the LD-dissociated period indicated in the periodogram (B); black horizontal boxes indicate the 24-h periods during which blood samples were taken every two hours during misaligned (<i>top, “C”</i>) or aligned (<i>bottom, “D”</i>) phases. B) The X² periodogram analysis of locomotor activity revealing two statistically significant rhythmic components (22 h and 25 h) in the animal shown in (A). C and D) The plasma corticosterone profiles (raw data) determined for the one animal shown in (A) during the days of misalignment and alignment, respectively. The dotted line in (C) represents predicted values between initial (t = 10: 00) and final (t = 8: 00) sampling times. Grey shading indicates time of lights off. E) Schematic diagram of predicted <i>Per1</i> expression patterns in the subregions of the SCN at 5.5 h after lights-on or lights-off on days of alignment and misalignment. Predicted <i>Per1</i> expression patterns (grey and white for high and low expression, respectively) are based on previous studies [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068793#B20" target="_blank">20</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068793#B22" target="_blank">22</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068793#B28" target="_blank">28</a>].