Fig. 2. The density of glial cells and the glia to neuron ratio are increased in myenteric plexus of mice over-expressing BMP4.

The immunoreactivity of S100β was used to identify enteric glial cells in whole mounts of laminar preparations of bowel containing the myenteric plexus. A. WT mouse. Inset: A high magnification image of the cell body of an S100β-immunostained glial cell body (arrow). Cuprolinic blue counterstaining. This is the type of preparation used to quantify glia; note that glial processes wrap around the light blue non-immunostained neurons. B. Heterozygous NSE-BMP4 (BMP4/+) mouse. The ganglia and connectives of the myenteric plexus are made visible by the brown S100β immunoreactivity of enteric glia. The clear lacunae in the glial network are the non-immunostained neurons. The bars = 60 µm. C. The glial density (glia/mm² plexus) was quantified (see Fig. 2A inset) and expressed as % of WT. D. The glial density was normalized to that of neurons (marked by staining with cuprolinic blue [see Fig. 1 and 2A inset, above]) and expressed as a glia/neuron ratio. Both the glial density and the glia/neuron ratio were significantly greater in BMP4/+ than in WT mice. * p < 0.001, n = 12.