Figure 4.

The Midline-Estimating Statistic of Rhythms (A) and amplitudes (B) of the core and peripheral temperatures and the differences between these temperatures for the values obtained for each parameter in young and old ringdoves treated with melatonin (0.25 and 2.5 mg/kg of b.w. 1 hour before lights off, respectively) or old ringdoves treated with tryptophan (300 mg/kg of b.w. 1 hour after lights on). Each value represents the mean ± SD of 10 determinations. *p < .05 with respect to the values obtained in their respective control groups.