Figure 6

Extracellular 11A1 immunoreactivity. (A) Representative images of an extracellular 11A1 immunoreactivity of inferior parietal cortex, layer V (63x objective lens). Left panel shows the merged image of 11A1 (green), MAP2 (red) and ALDH1L1 (magenta) signals. The area outlined by the white rectangle is magnified in the right panel and shows the extracellular 11A1 immunoreactivity. Scale bar 5 µm. (B) Representative immunostaining patterns of 11A1 antibody in neurons, astrocytes and pericapillary spaces in human cerebral cortex (63x objective lens). The row of figures shows immunostaining with 11A1 (green) and cellular/compartment marker (red) antibodies combined with DAPI staining. The cellular marker for neuron is MAP2 and for astrocyte is ALDH1L1, for pericapillary space is Collagen IV. The 11A1 immunoreactive particles form clusters around the DAPI signal in neurons and astrocytes. In the pericapillary space, there are both clusters and rows of 11A1 immunoreactive particles near the DAPI signal (blue). Scale bar 5 µm. (C) Staining pattern of the extracellular 11A1 immunoreactivity (green) ≥5 µm apart from DAPI signals (blue). In this compartment, the 11A1 immunoreactive particles do not form clusters, as seen in Fig. 6B, but appear as single and isolated structures independent of neuronal and astrocytic cell bodies and of blood vessels. Scale bar 5 µm. (D) Colocalization of the extracellular 11A1 immunoreactivity (green) with CD63 signal (magenta). The criteria for the identification of the extracellular 11A1 immunoreactivity is described in the method section. The rows of figures correspond to three age groups: early 30 s, middle 40 s, and early 60 s. Scale bar 5 µm. (E) Total number of the extracellular 11A1 immunoreactivity in measured area across the age-spectrum (30–65 years). The relationship with age is not statistically significant before age 45 (P = 0.51), but it becomes highly significant after age 45 (P < 0.0001) by the Piecewise regression. (F) Colocalization of 11A1 (green) and CD63 (magenta) immunoreactivity in protoplasmic astrocytes. The rows of figures correspond to three age groups: early 30 s, middle 40 s, and early 60 s. Left panels show the 11A1 signal, middle panels the CD63 signal, and right panels the merged images. The white line in the merged images indicates the cell shape identified by GFAP signal. Scale bar 5 µm. (G) Representative image of 11A1 labeled Aβ plaque and CD63 signal. Left panels show the 11A1 labeled Aβ plaque (green), middle panels the CD63 signal (magenta), and right panels the merged images. Scale bar 5 µm.