Fig. 2.

Double-plotted actograms of two hamsters that received melatonin injections in the evening (circles) and vehicle (diamonds) in the morning (group 2) for 7 days immediately after transplantation (T). The hamsters also received injections (as indicated) 6 weeks after transplantation. Theheavy vertical lines are the eye fit lines used to estimate the phases of activity onset on the day after the initial set of injections (top end of the line).Asterisks on the time scales at the tops of the actograms also indicate the phases. Eye fit lines before and after the later set of injections were used to assess the effects of the later injections. Record B shows an advance phase shift in response to vehicle injections. The VIP-immunoreactive grafts of animals A and B are shown in Figure 3, C andD.