Fig. 1.

Effects of long-term intracerebroventricular infusion of CRH on the circadian rhythms of body temperature (A, B) and locomotor activity (C, D) in rats (Protocol A). Body temperature (°C) and locomotor activity (arbitrary units) were measured continuously during 6 d of treatment with use of biotelemetry. The shaded areas indicate the dark periods. The data shown in A and Crepresent means over 30 min [•, intracerebroventricularly vehicle-treated control rats (n = 12); ○, intracerebroventricularly CRH-treated rats (n = 9); SEM values were omitted for the sake of clarity]. The time points on the x-axis correspond to the time of the day at which collection of the 30 min sample was started. The data depicted in B and D represent mean ± SEM over 6 hr (closed bars, intracerebroventricularly vehicle-treated rats; hatched bars, intracerebroventricularly CRH-treated rats). For this purpose, the 24 hr of the day were divided into four periods of 6 hr, of which periods 1 and 2 denote the light phase and periods 3 and 4 represent the dark phase (as shown on the x-axis). For more details see Materials and Methods. *, Significantly different from intracerebroventricularly vehicle-treated rats (Student’st test). For additional statistical analyses, see Results.