AdBDNF injection increased recruitment to the olfactory bulb. A, B, BrdU+ cells in the olfactory bulbs of AdBDNF:IRES:hGFP (A) AdNull:GFP (B) injected brains, at day 20. C, Stereological reconstruction of BrdU+ cells, viewed here at different mediolateral levels of the olfactory bulb, revealed substantially higher BrdU+ cell densities in the olfactory subependyma and granular layers of AdBDNF-treated rats (C) than in their AdGFP-injected controls (D). Arrows denote entry to rostral migratory stream in red. E, The average number of BrdU+ cells/mm3in the olfactory bulb (n = 4 per group), plotted as a function of treatment, again revealed significantly higher numbers of newly generated BrdU+ cells in AdBDNF-treated rats than their controls.