Figure 4.

Experimental design. We used a total of four rats in the present microarray studies, two for the circadian day (8 hours after lights on, rats (a) and (b)), and two for the circadian night (2 hours after lights off, rats (c) and (d)). From each rat we obtained coronal slices that contained two SCN (left and right), separated by the third ventricle. Slices were separated along the third ventricle and placed in media containing EGF (20 nM) or control vehicle (C) for one hour. RNA for use with the microarrays was then extracted from SCN punches from the slices.