Fig. 2.

Long-term multiunit activity as a function of circadian time. Circadian time was determined on the basis of drinking actograms. The recordings were performed in constant darkness. The onset of drinking activity is the onset of the subjective night and corresponds with CT 12. The subjective night is shaded. Multiunit discharge inside (A) and outside (B) the SCN was counted every 10 sec.Dots represent mean values per minute. At the bottom of each figure, movement artifacts have been plotted. The gaps in the multiunit traces are the consequence of the exclusion of data bins in which movement artifacts occurred.