Fig. 4

Different parts of meniscus immunohistochemically stained by substance-P. a) In anterior horn, SP+ fibers could be identified accompanied with blood vessels (black arrow); b) In inner third at the junction between anterior horn and anterior body, a small amount of isolated myelinated nerve fibers with SP+ can be seen; c). In outer third at the anterior body, SP+ fibers (black arrow) and blood vessels and connective tissue (red arrow) were observed; d). Thin, unmyelinated SP+ nerve fibers could be seen in outer third at the middle body; e). No nerve fibers or receptors were detected in the inner third of the posterior body of menisci; f). In inner third at the posterior horn, large amounts of SP+ fibers could be found; g). A medial meniscus was sectioned by five parts (black line) and specimens immunohistochemical stained from specific part were shown as (a)-(f)