Figure 2.

Correlations between the slope of the ongoing baseline change in gene expression, the gene expression at sleep deprivation onset, and the sleep-deprivation induced change in gene expression. Depicted are linear regression lines (solid) and their 95 % confidence interval (delimited by paired dashed lines) for the partial correlations of Dbp, Per2, and Homer1a transcripts (top to bottom panels, respectively) calculated for the dependence of the sleep-deprivation (SDep)-induced change in gene expression on either the ongoing baseline change in expression (i.e., “slope,” left panels, green symbols), or the expression at sleep-deprivation-onset (right panels, blue symbols). The effect of the level of expression at sleep-deprivation-onset was removed for assessing the effect of slope on the effect of sleep deprivation and vice versa (i.e., partial correlations). Analyses are based on the mean values obtained in the 3 inbred strains (n = 3/sleep deprivation, total n = 12; see Figure 1). Partial correlation coefficients are indicated (r_par; P-values in parentheses). Note that for Homer1a the sleep-deprivation-induced increase depends only on its expression at sleep-deprivation-onset, while for Dbp and Per2, the sleep-deprivation-induced change depends almost exclusively on the ongoing change in expression under baseline conditions (or “slope”). Further note that the data points can no longer be directly compared to those in Figure 1, as these are adjusted according to the partial correlations.