Effect of sleep and sleep deprivation on the expression of core clock components. The expression of exemplar circadian genes is plotted as a function of time in both the heart and lung. Changes in transcript expression from baseline conditions (lights on) are plotted as a percent of baseline expression levels. Maroon curves show data from experimentally sleep-deprived animals and blue curves show data from spontaneously sleeping animals. Data from heart tissue is connected with dashed lines. Data from lung tissue is connected by uninterrupted lines. Transcripts annotated with a (*) or (+) showed differential expression in the lung or heart respectively (p < 0.001). Data shown represents mean ± standard error for 8 or 9 biological replicates.