Fig. 5.

Effect of age or DNJ on IGF-1R immunohistochemical staining in the dorsal hippocampus. Representative low-magnification photos in the O-con (a), Y-con (b), HD-DNJ (c), and LD-DNJ (d) groups are shown. An IGF-1R immunoreaction was detected in all layers of the O-con. For the Y-con, an IGF-1R immunoreaction was mainly detected in the DG-GL, CA1-PL, and CA3-PL. The analysis of average optical density showed that DNJ decreased the elevated IGF-1R level in the old controls. DG dentate gyrus, GL granule cell layer, PL pyramidal cell layer. Scale bar = 400 μm