Abnormal enteric innervation identified without histopathologic staining in aganglionic colorectum from a mouse model of Hirschsprung's disease.

PURPOSE: The piebald lethal mouse with a deletion of endothelin-B receptor gene (EDNRB) is a model for Hirschsprung's disease (HD), whereas the SOX10 gene is vital for the development of intestinal neural crest-derived cells. Recently, we created a SOX10 transgenic mouse with intestinal neural crest-derived cells visible with enhanced green fluorescent protein (VENUS), that is, SOX10-VENUS(+)/EDNRB(sl/sl) to investigate intestinal innervation in HD.

METHODS

SOX10-VENUS(+)/EDNRB(sl/sl) (n = 30) were compared with wild-type littermates as controls (EDNRB(s/s), n = 30). Mice were killed on days 3, 7, or 12 of age. The entire colorectum was excised, fixed with 4% paraformaldehyde, and examined using fluorescence microscopy alone without staining.

RESULTS

In normoganglionic colorectum from controls, a grid network of nerve fibers/glial cells was visualized that connected smoothly with extrinsic nerve fibers running along the colorectal wall. In aganglionic colorectum from SOX10-VENUS(+)/EDNRB(sl/sl) mice, there was no grid network and more extrinsic nerve fibers than controls that invaded the colon wall becoming elongated with branching fibers. Normoganglionic colon from controls and SOX10-VENUS(+)/EDNRB(sl/sl) mice appeared the same. Innervation patterns did not change over time.

CONCLUSION

This is the first time for abnormal enteric innervation in aganglionic colon in a model for HD to be visualized without staining.