Figure 6.

Mid-subjective day dark pulses suppress the suprachiasmatic nuclei and activate the median raphe. Histograms show expression of c-Fos (mean ± SEM) at CT6 and CT9 in constant light (gray-filled histograms) and 1 h and 4 h into a 6 h dark pulse beginning at CT5 (black-filled histograms) in the SCN (A), IGL (B), DRN (C), and MRN (D). **p < 0.01.