Culture of isolated embryonic chick dorsal root ganglia at an air-liquid interface: a simple method for studying the mechanism and control of neurite outgrowth.

Extensive neurite outgrowth occurs within 24 h from explants of embryonic chick dorsal root ganglia floated on the surface of serum-free culture medium. The amount of neurite outgrowth was less in culture medium containing serum albumen and varied systematically with the concentration of nerve growth factor (NGF). Compared with outgrowth from floating ganglia, the NGF-dependent outgrowth of neurites from ganglia stuck to coated substrata was much less on polylysine, but outgrowth was more extensive on a laminin-coated substrate. Neurites growing out from floating ganglia showed more fasciculation than those growing out from adherent ganglia. This new, simple preparation provides a serum- and substrate-independent system for studying mechanisms of neurite outgrowth and for quantitative bioassay for potential neurotrophic factors or for factors which influence neurite fasciculation.