The olfactory bulb (OB), with its comparatively simple and well-delineated connectivity, presents an interesting system for examining cell-specific pathology in neurologic degenerative disorders such as Alzheimer's disease (AD). We have found that in AD the large, efferently projecting neurons (mitral cells) of the OB degenerate, typically without classical Alzheimer neurofibrillary changes. In some cases, with less severe neocortical pathology, the terminal arborizations of olfactory nerve appear hyperplastic and are associated with focal accumulations of A-4 (β-amyloid) immunoreactivity that are not detectable by standard amyloid stains. These abnormalities may represent a pathologic manifestation of normally occuring plasticity in the olfactory system.
Bibliographical noteFunding Information:
This work was supported by Southern Illinois University Central Research Committee and NIH Grant AGO8014. We express our sincere gratitude for the generosity ofD. J. Selkoe, F. L. Margolis, and W. Van Nostrand, who supplied the antisera used in this study. We also thank R. J. Elble for editorial comments and S. K. Murphy and C. Gre-gurich for expert technical assistance.
- Alzheimer's disease
- Olfactory system