Figure 4.

Immunohistochemical visualization of neurotrophin receptor p75 (p75), S100 calcium binding protein B (S100 beta) and sodium channels. (A,B) Detection of the protein for neurotrophin receptor p75 underpinned assumptions of less number of neural progenitor cells in aged human myenteric plexus. The number of p75-positive cells marked by arrowheads could be shown in higher number in young tissue in (A) compared to aged colon in (B). (C,D) In contrast, a slight relative increase of S100 beta-expressing cells was observed in aged tissues of proximal colon. (E) Although slight cross-reaction with cell nuclei in the muscle tissue was detected, sodium channel Na_v1.6 could be demonstrated exclusively in myenteric plexus, representatively shown for one child and marked by arrowheads. (F) The sodium channel subtype Na_v1.9 was identified in ganglion cells (marked by arrowheads) and in muscle tissue (marked by arrows). (A–F) outer longitudinal (LM), inner circular muscle (CM); nuclei stained with DAPI (blue); scale bar 100 μm.