Electron microscopic studies on embryonic chick spinal ganglion cells: relationship between microtubules and the...

Spinal ganglia from 11 day chick embryos were fixed immediately after removal, or after a short incubation in media with or without nerve growth factor (NGF), and were subsequently examined by transmission electron microscopy. Qualitatively, incubation did not effect the fine structure of the neuroblasts. Morphometrically, however, NGF was found to cause a marked increase in the amounts of microtubules and microfilaments in the perikarya of the cells with a threefold increase in the volume density of these organelles after 4 h. The cells displayed a prominent Golgi complex, mostly with dictyosomes organized in one continuous band or area. Individual dictyosomes consisted of a stack of 3-6 parallel cisternae associated with small vesicles and occasional larger vacuoles. Microtubules were observed in all parts of the cyotplasm but were particularly numerous within the Golgi area. They occurred both on the forming and maturing sides of the dictyosomes and in the latter site were closely associated with small vesicles and peripheral dilatations of the cisternae. These observations indicate a possible role of microtubules in the organization and function of the Golgi complex.