FIG. 1.

Urinary bladder matrix (UBM) injection does not activate microglia, does not cause astrocytosis or neurodegeneration. (a, b) There was no discernable increase in expression of the microglia, or astrocyte activation indicator Iba-1 or GFAP, as measured by immunofluorescent staining between UBM- and vehicle-treated cerebral hemispheres. The representative images shown here are the tissue regions from the needle track to the injection site. The white arrow indicates the needle track and the tip of the arrow is the injection site. Note the increased number of activated microglia along the needle track at day 3, which subsided by day 21 in both UBM- and vehicle-treated hemispheres. Histological sections are representative of the findings from both hemispheres with an n=3 rats per time period. (c, d) Immunofluorescent staining for GFAP presented little difference between UBM- and phosphate-buffered saline (PBS)-injected brain tissue after 1, 3, and 21 days. n=3 rats per time period at 1, 3, and 21 days following injection. (b, d) High magnification of the images at day 3 shows the morphology of activated microglia and astrocytes near the injection site of both groups. (e) Staining UBM- and vehicle- injected brain sections with the neurodegeneration marker FluoroJade-B indicates that UBM treatment does not result in more degenerative neurons than control (PBS injection). There was a slight presence of degenerative neurons around the tip of injection on day 1 after injection, but this was equal between UBM- and vehicle-treated hemispheres. Histological sections are representative of the findings from both hemispheres with an n=3 rats per time period. Scale bar: 1 mm in (a, c); 40 μm in (b, d); 100 μm in (e). Color images available online at www.liebertpub.com/tea