FIG 3.

VSV is limited to the OB, whereas IFN-induced proteins are widely expressed following intranasal infection. (A) A few periglomerular cells (arrows) show VSV-GFP, and strong expression is found in dendrites in the external plexiform layer (EPL). (B) A 4′,6-diamidino-2-phenylindole (DAPI) counterstain shows cell nuclei in the olfactory bulb. (C) Merged photomicrograph showing the images in panels A and B. Scale bar, 34 μm. (D) VSV-GFP is found in the granule cell somata (GC), indicated by three arrows, and their dendrites in the GCL. (E) NeuN immunostaining shows the nuclei of neurons. (F) Merged photomicrograph shows that VSV-GFP-labeled cell bodies contain red NeuN-labeled nuclei, indicating the infected cells are neurons. Scale bar, 22 μm. (G) Higher magnification of granule cell dendrites in the EPL. Scale bar, 9 μm. (H) Despite strong infection of neurons in the olfactory bulb, no virus was detected in cortex. Scale bar, 30 μm. GL, glomerular layer. (I) Western blot analysis shows upregulation of IFIT3 and actin (ACT) protein expression in mice administered intranasal VSV compared with saline (−) controls.