Figure 2

Time-dependent odorant induced CREB phosphorylation. (A) Staining for phospho-CREB (Ser-133). Low levels of basal phospho-CREB were observed in the nuclei of OSNs and immature OSNs not expressing OMP, with little or no staining in the sustentacular cell layer. An increase in phospho-CREB in the sustentacular cell layer was observed after 15 min of exposure to a mixture of 100 different odorants, and after 2 hours positive staining for phospho-CREB was observed in the nuclei of OSNs, immature OSNs not expressing OMP and the sustentacular cells. Scale bar 20 μm. (B) High magnification image (2X) of a section of the images in A, clearly showing the increase in CREB phosphorylation in the sustentacular cell layer (arrowhead) and in the OSNs (arrow) after 2 h odorant treatment. Scale bar 20 μm. (C) Bar chart shows mean ± SD average fluorescence intensity along the nuclei of different cell types indicated, normalized to cytosolic background staining. Sustentacular cell nuclei layer, control 0.96 ± 0.33 n = 78, 15 min odorant 4.88 ± 0.68 n = 71, 2 h odorant 7.10 ± 0.59 n = 76. OSN nuclei layer, control 2.58 ± 1.47 n = 68, 15 min odorant 2.80 ± 0.81 n = 81 (p = 0.24), 2 h odorant 4.16 ± 3.11 n = 74. Immature cell nuclei layer, control 0.79 ± 0.69 n = 74, 15 min odorant 2.76 ± 0.24 n = 79, 2 h odorant 3.97 ± 0.86 n = 69. n represents one standard field of view at 40 × magnification and 2 × zoom, one-way ANOVA p*** < 0.001, p** < 0.01. Three mice were used for each condition and four cryosections with complete olfactory epithelium were quantified per mouse.