BETA-AMYLOID PRECURSOR PROTEIN-LIKE IMMUNOREACTIVITY IS UP-REGULATED DURING OLFACTORY NERVE REGENERATION IN ADULT RATS

beta-amyloid precursor protein (APP) is the source of beta-amyloid, wh ich forms the cores of senile plaques in Alzheimer's Disease. However, the function of this precursor protein is currently unknown and an ad ult animal in which this protein varied substantially would be valuabl e. We used subcutaneous diethyldithiocarbamate to reversibly lesion th e olfactory epithelium in adult rats and found that whole-bulb levels of APP-like immunoreactivity significantly decreased after the lesion, then increased reaching almost five-fold normal levels six weeks afte r treatment. Growth cone associated protein (GAP43) decreased when the nerve degenerated, then increased, replicating previous studies of ol factory nerve regeneration. Immunocytochemical techniques identified A PP immunoreactive perikarya and fibers in and around glomeruli at thre e days to one week post-lesion and upregulation of APP-like immunoreac tivity in mitral cells and dendrites at five weeks. Olfactory nerve re generation appears to be a useful in vivo model system to understand t he regulation of APP-like proteins. (C) 1998 Elsevier Science B.V.