Sympathetic neurons extend neurites in a culture medium containing cyanide and dinitrophenol but not iodoacetate.

A culture medium circulated through the rat heart and supplemented with insulin, transferrin and nerve growth factor leads to a massive proliferation of neurite outgrowth from neurons of peripheral sympathetic ganglia of the chick embryo. Addition of 1 mM cyanide or 50 microM dinitrophenol to such medium for 2 days had no adverse effect on the neurite outgrowth and ATP content of these neurons. However, 0.5 microM iodoacetate lowered ATP content 65% without affecting the number of surviving neurons up to 2 days. Only when ATP content was reduced to 80% by 2.5 microM iodoacetate was the number of surviving neurons significantly reduced (30%). It is concluded that the glycolytic pathway is the major route of ATP synthesis in embryonic sympathetic neurons maintained in culture, and only a small fraction of ATP is utilized for the survival and neurite extension.