Adult rat cerebellum was examined for the presence of nerve growth factor receptor (NGFr) immunoreactivity (IR) using the monoclonal antibody 192-IgG. In normal animals, light NGFr-IR was observed consistently in Purkinje cells and molecular layer throughout the flocculonodular lobe. However, animals treated with intracerebroventricular colchicine 7-72 h prior to analysis displayed a graded increase of IR in Purkinje cells of all regions with progressively longer survival times. These findings demonstrate the usefulness of colchicine in revealing accumulation of NGFr in adult CNS neurons where previously not visualized and suggest responsiveness of a non-cholinergic neuronal population to nerve growth factor (NGF).