Effect of fetal alcohol exposure on olfactory bulb neurogenesis. (a) Postnatal OB neurogenesis was assessed using 3 methods: (i) in vitro neurosphere assay, (ii) in vivo labeling with BrdU, and (iii) in vivo labeling with LacZ using a transgenic reporter system. (b,c) FAE mice (n = 9) had fewer in vitro neural precursor cells and fewer small neurospheres in the SEZ compared to control mice (n = 9) between P4 and P14. (d) FAE mice had fewer BrdU+ cells in the granule cell layer of the OB compared to control mice P7 (control n = 9, FAE n = 8) and P21 (control n = 8, FAE n = 9). (e) There was no difference in BrdU+ cells between control (n = 8) and FAE mice (n = 8) at P60. (f) FAE reporter mice had fewer LacZ+ cells in the granule cell layer of the OB at P30 (control n = 8, FAE (10%) n = 6, FAE (15%) n = 9).