Fig. 4

Bioluminescence signal intensity changes associated with OR task. a Experimental schedule for OR task and BLI. Bioluminescence signal intensity was measured in each mouse 6 h after putting a plastic cube into their home cage (Object). For the Control, no object was presented. BLI was also performed without any treatment 1 day before the OR task (Base). The time points of BLI are indicated with black triangles. b Representative images of bioluminescence signals (pseudocolored, 3000–15,000 counts) in the Arc-Luc Tg HL mouse brain at 4 weeks of age for the Object and Control. Location of ROIs in the forebrain is indicated in the Control image. Scale bar 10 mm. c Subdivision of ROI in forebrain into smaller rectangles at 0.35 mm intervals in rostral to caudal direction. d Distribution of bioluminescence signals associated with OR (n = 7). Profiles of photon density throughout the forebrain for object presentation (red line) and control condition (black line). Each value obtained from ROIs in (b) was normalized to the mean signal intensity (photon density = 1.0) in the whole forebrain. Significant differences between the control and OR conditions are shown in gray (0–1.4 mm and 4.55–7.35 mm from the rostral end) in the graph. The data represent mean ± SD. *p < 0.05; two-tailed Student’s t test