The effect of fibronectin on cholinergic differentiation of the fetal colon.

In an effort to determine the factors which affect cholinergic development after completion of migration of neural crest cells to the colon, the extracellular matrix constituents, fibronectin, collagen IV, laminin, and heparan sulfate were studied during this later postmigration stage of differentiation. Distal colons of the 14 1/2 day embryo rat were incubated in vitro with antibodies to the above constituents or with fibronectin alone. Cholinergic function of the colon was assessed by acetylcholinesterase staining and choline acetyltransferase activity. When 100 micrograms/mL of fibronectin was added to the medium, the choline acetyltransferase activity was enhanced; when antibody to fibronectin (50 or 100 micrograms/mL) was added, acetylcholinesterase staining and choline acetyltransferase activity were inhibited. Addition of anti-laminin, anti-collagen IV, or anti-heparan sulfate did not affect either acetylcholinesterase staining or choline acetyltransferase activity. Fibronectin may be an important factor in cholinergic differentiation of the enteric nervous system during the postmigration stage of development.