Table 4.

Migration Rates of OPCs in Culture

Time	Migration rate
	PDGF	PDGF + bFGF
d*	μm/h‡
5	23 ± 3	24 ± 2
60	21 ± 3	22 ± 2
150	13 ± 2	19 ± 2
300	6 ± 3	16 ± 1
420	5 ± 1	15 ± 3

*Purified P7 OPCs that had been in culture for various periods of time were cultured in B-S medium containing either PDGF or PDGF + bFGF for the days indicated.

^‡Cell migration was determined by measuring the distance that the cell body moved during a randomly chosen period of time. Time-lapse video recordings were performed for 48–96 h. Clones of 2–10 cells were chosen, and 15–20 cells from 3–5 different clones were analyzed for each time point. The results are shown as mean ± SEM.