Effects of nerve growth factor from the venon of Vipera russelli on sensory and sympathetic ganglia from the embryonic chick in culture.

Sensory and sympathetic ganglia of embryonic chick were cultured in media in which no growth of fibres occurred, and then transferred to culture conditions favouring the growth of fibres. The effects on fibre outgrowth of having NGF in neither, one or both media were examined quantitatively. It was concluded that the main effect of NGF, under these conditions, is to maintain the viability of the neurons. Subsidiary experiments supporting this view are also reported.