In order to compare the BrdU results to another cell cycle marker, Ki-67, an endogenous marker of all active phases of the cell cycle (excluding Go, the resting state), was examined in adjacent sections of 4D tissue. Ki-67 immunolabeling was similar to BrdU in that it was punctate with clusters spread throughout the subgranular zone (Figure 4). However, the number of Ki-67-positive (Ki-67+) cells was not different between the ethanol (n=6) and control groups (n=6). This lack of effect indicates that similar numbers of cells are in the active phase of the cell cycle despite binge alcohol intoxication.
