Axonal outgrowth and cell migration in vitro from nervous system of cockroach embryos.

Brain and ganglia of embryonic Periplaneta americana were grown for 2 to 3 weeks in a chemically defined medium. Nerve fibers sprouted vigorously from intact brains and ganglia, interconnecting nerve cultures, and adjacent cultures of the digestive tract, Glia, tracheal, and nerve cells were present in large numbers in the migratory zone surrounding the explants.