Mast Cell Activation, Neuroinflammation, and Tight Junction Protein Derangement in Acute Traumatic Brain Injury

Figure 2

Acute TBI increases mast cell number and degranulation in the brain. Mast cell number and its degranulation were evaluated in the frozen sections (20 μm) cut from the brains after 24 h and 72 h of weight drop-induced TBI and sham control mouse brains without TBI ( mice/group). These brain sections were stained with 0.1% toluidine blue solution for mast cell detection. The number, as well as activation (purple, black arrows) of mast cells, was increased in 24 h and 72 h TBI brains as compared with sham control mouse brains without TBI (a). Note the presence of widespread extracellular granules in degranulated mast cells. Degranulated mast cells also appear irregular in shape. Control mast cells without degranulation did not show extracellular cytoplasmic granules. Photomicrograph original magnifications = 100x. Representative photomicrographs show increased number and activation of mast cells in 24 h and 72 h TBI brains as compared with sham control brains without TBI (a). Photomicrograph original magnifications = 100x. The total number of mast cells was increased in TBI brains as compared to sham control mouse brains (b; , sham control vs. TBI).

(a)

(b)