Figure 4.

Newly generated cells in the adult macaque monkey OB 97 days after the last of five BrdU injections. (a–d) Granule neurons in the OB express NeuN (red), and astrocytes express GFAP (blue). (a and b) A cell in the granule cell layer that is labeled with BrdU (arrow, yellow green in b) also expresses NeuN (arrow, a), indicating a newly generated granule neuron. (c and d) An example of two BrdU-labeled nuclei (d, arrows, green) that did not emit a red fluorescence signal (c, arrows), demonstrating that the BrdU signal did not bleed into the red channel; these might be progenitors or newly generated nonneuronal cells. (Bars = 20 μm.)