Effects of olfactory mucosa conditioned medium on olfactory bulb (OB-ns) and subventricular zone neurosphere cell (SVZ-ns) proliferation. (A-D) Photomicrographs of 7 day old olfactory bulb neurospheres expanded in bFGF/EGF (control 1 shown in A and control 2 shown in B) and in OM-CM (C and D). (D) High magnification of photomicrograph C revealing cells located away from the core of the neurosphere (arrows). (E-F) Graphs showing proliferation curves of control cultures (control 1 and control 2) and neurosphere cells derived from the olfactory bulb in (E) and from the subventricular zone (F) cultured in OM-CM. (G) Semi-quantitative RT-PCR showing expression level of the neural stem and progenitor cell markers in OB-ns in control cultures and OM-CM. Scale bars: 100 μm in A-C and 50 μm in D.