Abstract
Spinal ganglia from 11 day chick embryos were incubated in media containing colchicine or vinblastine and subsequently examined by transmission electron microscopy. Both drugs caused a partial disappearance of cytoplasmic microtubules and a concomitant growth in the number of microfilaments in the neuroblasts. In ganglia treated with vinblastine for 4 h these effects were recorded morphometrically as a decrease of about 80% in the volume density of microtubules and a more than tenfold increase in the volume density of microfilaments. Furthermore, the cells displayed marked structural changes in the Golgi complex. The dictyosomes were mostly distinctly separated from each other and individual dictyosomes showed a decreased number of cisternae and an increased number of closely associated large vacuoles. The results are discussed with regard to the role of microtubules in the organization and function of the Golgi complex in nerve cells.