Phase-contrast cinematographic study of dissociated neurons from embryonic chick dorsal root ganglia cultured in the rose chamber

1. 1. Mechanically dissociated neurons of spinal ganglia from 14–15 day chick embryo were studied from 1 day to 2 months after cultivation by means of time-lapse cinematography. 2. 2. During the first 2–3 days, rounded neurons produced multiple short and thin processes. Some of the processes degenerated so that mostly bipolar neurons were formed. Some multipolar and pseudounipolar neurons were also observed in older cultures. 3. 3. Cultured neurons displayed nuclear rotation and movement of nucleoli. 4. 4. The organization and behavior of fibers and their contacts was described. Of particular interest is the variety of contacts made to the free surfaces of neurons and their influence on cell viability. 5. 5. Irregular phase-dense bulbs were observed moving along some nerve fibers. Dividing Schwann cells were seen in the free state and others displayed mobile activity in association with fibers. The rate of mobility was approx. 15 μ/h. 6. 6. Free neurons underwent passive movements induced by push-and-pull forces of other migrating cells. Such movements amounted to 3–5 μ/h or approx. 110 μ in a 24-h period. 7. 7. Typical satellite cells were seen to be reassociated with previously isolated neurons in older cultures. These glial cells displayed mobility patterns and cell division.