An Enteroendocrine Cell – Enteric Glia Connection Revealed by 3D Electron Microscopy
Figure 3
3D ultrastructure reveals axonal process escorted by enteric glia.
A. Enteroendocrine cells compared to other intestinal epithelial cells express neurofilaments light and medium (top panel). Neurofilament proteins light and medium are expressed in 22% and 47% of Pyy-GFP cells, respectively (bottom panel). This quantification was performed using immunohistochemistry with neurofilament-specific antibodies. B. Top panel is a representative image showing that neurofilament heavy is expressed in subepithelial myofibroblasts but not in enteroendocrine cells. Neurofilament light is contained within the Pyy-GFP cell basal process (bottom panel). C. Enteroendocrine cells contain neurofilament medium within the neuropod. Inset shows the position of the cell in the epithelium of the ileum. 3D reconstruction of confocal z-stacks depicts the neurofilament medium contained within the Pyy-GFP cell neuropod. D. The SBEM data also revealed the relationship between the neuropod in the Pyy-GFP cell and enteric glia. Enteric glia trespass the basal lamina and penetrate into the epithelium (inset). SBEM data segmentation revealed that the enteric glia extends a cytoplasmic process into the epithelium that contacts the enteroendocrine cell neuropod. Bars in B and C = 10 µm, in D = 1 µm.