Fig. 3.

The fate of newborn cells is not affected in β₂^-/- mice. (a and b) Confocal microscopy images of BrdUrd (red) and NeuN (green) double-immunofluorescent labeling in the OB granule cell layer, 21 days after BrdUrd injections (n = 3 per genotype). Reconstructed orthogonal projections are presented as viewed in the x-z (Upper) and y-z (Right) planes. The proportion of double-labeled (yellow) cells did not differ between β₂^+/+ and β₂^-/- mice (b), as determined from the analysis of almost 1,000 cells per group. (c and d) Decreased apoptosis in the granule cell layer of β₂^-/- mice. (c) TUNEL staining in granule cell layer sections from adult β₂^+/+ (Left) and β₂^-/- mice (Right). Arrows point to apoptotic cells. (d) Significantly fewer apoptotic profiles were found in β₂^-/- mice. β₂^+/+, n = 3, and β₂^-/-, n = 4; ^*, P < 0.05 by Student's t test. (Scale bars: a, 10 μm; c, 25 μm.)