Subserosal localization of myenteric ganglia in normal human appendix: immunostaining with neuronal and glial markers

Visualization of unexpected distribution of myenteric ganglia in normal human appendiceal wall by immunofluorescence.

The myenteric plexus is located between the longitudinal and circular muscle layers of the GIT. However, recently the irregular distribution of myenteric ganglia was revealed in human appendix.

The cryosections prepared from normal human appendices were examined by immunofluorescence methods using antibodies to neurofilaments (NF) and glial fibrillary acidic protein (GFAP).

Indirect immunofluorescence revealed the positive staining of myenteric ganglia with both neuronal and glial marker antibodies. Double labeling for NF/GFAP staining showed close assotiation between glia and neurons inside ganglia. GFAP-positive cells were often observed as the cells surrounding myenteric ganglia. The staining confirmed the irregular distribution of myenteric ganglia in human appendiceal wall and revealed the small ganglia in the subserosal area.

Our results showed that localization of myenteric ganglia in human appendix differs from other parts of GIT. GFAP immunostaining is available for visualization of smaller myenteric ganglia located mainly in the subserosal area. Our studies may find application in current HIV research focused on enteric neuropathogenesis and in diagnostic laparoscopy for chronic abdominal pain: to detect the irritation of subserosal ganglia (Fig. 2, Ref. 26).