Fig. 4
From: Aging-associated inflammation and fibrosis in arachnoid membrane
Illustration of the process of AM hyperplasia. Fibroblasts and VEGFα play an important role in AM hyperplasia. Infiltration of macrophages though chronic inflammation tends to distribute inward to the pial side adjacent to the brain surface, and the extracellular matrix including collagen fibers mainly exists at the outward dural side. Macrophage activation accelerates the elevation of TNFα and TGFβ and promotes fibrosis. Consequently, VEGFα levels increase in the AM. The depicted image is our own design. AM: arachnoid membrane