Fig. 1.

Representative immunohistochemistry of substance P (SP)-positive sensory nerve fibers and sympathetic tyrosine hydroxylase (TH)-positive nerve fibers. a, b SP-positive sensory nerve fibers embedded in extracellular matrix (a) and following a larger synovial tissue artery (b; blue fluorescence staining = DAPI, 4′,6-diamidino-2-phenylindol). c, d TH-positive sympathetic nerve fibers embedded in extracellular matrix (green intrinsic fluorescence demonstrating fibrillar structures). Micrographs were taken at ×400 magnification