Figure 6. Bromodeoxyuridine (BrdU) pulse chase experiment in animals having one central and one peripheral photocoagulation (PC) lesion
followed by a single pulse of BrdU. The number of labeled cells increased over days 1–7, then leveled off between days 7–9.
Levels of BrdU labeling in each case were greater in the periphery than in the center. The increasing number of cells found
over time was statistically significant (see test for). These data reveal that cell numbers double approximately between day
1 and day 7; hence the cell-cycle rate is likely to be roughly this long.