The fractions of biochemical markers expressed by adult born neurons are similar to those expressed by the overall population of olfactory bulb neurons labeled with NT. The percentage of BrdU or NT positive cells that also express NC, CR, GABA, TH, and CB in the GCL (A) and GLL (B). Data for all markers are similar except for GABA, which is expressed in significantly more new neurons (BrdU+) than in the overall population (NT+). Also shown, data from confocal imaging of new GCL neurons double labeled for Calretinin, GABA and N-copein. BrdU, bromodeoxyuridine; NT, NeuroTrace; NC, N-copine; CR, calretinin; TH, tyrosine-hydroxylase; CB, calbindin; GCL, granule cell layer; GLL, glomerular layer.