Responses to cell contacts between growth cones, neurites and ganglionic non-neuronal cells

The motility of growth cones of embryonic peripheral neurons is not inhibited by contact with the surfaces of neurites or of non-neuronal cells. Rather, growth cones and microspikes adhere to other cell surfaces and often respond with forward movement and elongation in contact with other cells, as they do on adhesive surfaces in vitro. Furthermore, non-neuronal cells do not display contact inhibition when they contact growth cones or neurites. If anything, surface motility and ruffling is stimulated by contact with a neuronal cell surface and some non-neuronal cells prefer to migrate along neurites rather than on the surface of the culture dish. These observations on the contact behaviour of cells from peripheral nerve ganglia imply that the surfaces of embryonic neurons differ from those of non-neuronal cells in that the neuronal surfaces do no elicit the typical contact inhibition response.