Fig. 4.

The effect of light (L) on PPARβ/δ immunoreactivity in the SCN is time-dependent. a In the hamsters maintained under the light–dark cycle, a 1-h light pulse given at ZT14 and 2 h after the light/dark transition produced an immunoreactivity that was similar to those observed during the light phase at ZT06 a, b significant difference p < 0.05, one-way ANOVA. b In the hamsters maintained under constant darkness, a light pulse given either during the rest phase (CT06) or 2 h after the onset of the active phase (CT14) exhibited an effect only at CT14 with a dramatic increase of immunolabeling. a, b Significant difference p < 0.05, one-way ANOVA. The values are presented as the mean ± SEM (n = 4 or 5). Above the bars representative diagram of PPARβ/δ distribution