Figure 1.

CB immunohistochemistry in the somatosensory cortex in the (A-C) mice, (D-F) rats and (G-I) gerbils. In all species, CB-immunoreactive neurons were primarily observed in layers II and III. The age-associated alterations were different amongst the species. The neuronal number in the aged was generally lower than that of the adults. Scale bars: (Aa-Ia), 200 µm and (Ab-Ic), 25 µm. (J) The percentage mean number of CB-immunoreactive neurons in whole layers in the somatosensory cortex. *P<0.05 vs. the young group; ^†P<0.05 vs. the adult group. Data are presented as the mean ± the standard error of the mean (n=7/group). CB, calbindin-D28k.