Abstract
The role of extracellular matrices during the development of ganglion cells of the chick colon was studied. Hematoxylin eosin and acetylcholinesterase stains were used to recognize differentiated ganglion cells. Organ culture techniques were used to know the stages when undifferentiated precursor cells migrate. Localization of three extracellular matrices, hyalu-ronic acid, sulfated GAG_s and fibronectin in the developing gut was examined using alcian blue stain (pH 2.5) with or without hyaluronidase digestion, 35^S-autoradiography, and immu-nohistochemistry respectively. In the distal colon of the chick embryo, ganglion cells were not recognized until stage 33 (8-day embryo). Organ culture studies revealed that the undifferentiated precursor cells had already migrated into distal colon at stage 29 (6-day embryo). Hyaluronic acid and fibronectin were rich along the way where precursor cells might migrate in the colon. Hyaluronic acid was depleted from the extracellular environment with migratory arrest and differentiation into the ganglion cells. Fibronectin, however, remained in the extracellular matrices during the ganglion cell differentiation. These results seem to indicate that hyaluronic acid and fibronectin promote the migration of undifferentiated cells and fibronectin accelerates the differentiation of ganglion cells.
