Fig. 2.

(a) Daily changes in total ambulatory activity for 60 min after subcutaneous administration of saline or BUP. All mice were given saline on days 1–3 (acclimation session). On day 4 (challenge session), one group was given saline (N = 7), and another group was given 10 mg/kg BUP (N = 10). Symbols show median values of total normalized ambulatory activity for 60 min after administration, and vertical lines denote the first and third quartiles. *P < 0.05 BUP vs. saline on day 4 (challenge session). (b) Time course of ambulatory activity before and after administration of saline or 10 mg/kg BUP on day 4. The arrow indicates time point for the administration. Immediately after the end of the ambulatory measurement, the mice were transcardially perfused with fixative, and their brains were later used for c-Fos immunocytochemistry. Symbols show median values of normalized ambulatory activity for each 10-min period. Symbols were plotted against the midpoint of the measurement period. Vertical lines denote the first and third quartiles. *P < 0.05 BUP vs. saline.